WO2014138821A1

WO2014138821A1 - Improved air purifying apparatus, method & use of chemical substance

Info

Publication number: WO2014138821A1
Application number: PCT/AU2014/000281
Authority: WO
Inventors: Richard Harold Rubin; Paul Geoffrey SMYTH; Roger Gordon White; Michael Paul BRALKOWSKI
Original assignee: Air Sanz Holdings Pty Ltd
Priority date: 2013-03-15
Filing date: 2014-03-17
Publication date: 2014-09-18
Also published as: TW201446710A; TWI720937B

Abstract

An air-purifying apparatus draws in an airflow from an ambient environment, kills germs in the airflow within the apparatus and expels the airflow purified back into the environment The apparatus has a housing with an interior chamber. An airflow enters the chamber through an inlet From the interior chamber, the airflow is expelled through an outlet. The apparatus has an airflow-germ-killing-system that kills germs in the airflow. The apparatus- has an airflow- generator which causes the airflow to flow from the inlet to the outlet. The airflow-germ-killing- system has a germ-killing-substance-effuser that effuses germ-killing-liquid-substance into the airflow. The germ-killing-liquid-substance comprises at least one antimicrobial agent.

Description

IMPROVED R_^TO

SUBSTANCE _;Pi?1d. FJnvemion

The present invention relates to a method and use of a chemical substance in apparatus which draw in an airflow from an ambient, human-activity environment, kill germs in the airflow, then expel the purified air from the apparatus back into the ambienteavironment,

Background

Human-activity environments, which are frequented by people, tend to be conducive for spreading germs and particularly disease-causing viruses among the people intermingling m the human-activity environment.

Moreover, mere is constant change in the variety of viruses that circulate through a human population in any particular season of time. Each year, there are new strains of viruses which are different from the strains from previous seasons. Thus, anti-virus substances, designed to counterac earlier variants, may not be as effective against strains that emerge in the new season.

When some, anti-virus substances are manufactured to be of sufficient strength to kill certain viruses, a side effect is that the strength of those antivirus substances can also

inadvertently pose a health risk to humans. There are germ-killing substances, adapted to be harmful to germs, that are also toxic to humans. For example, substances that are able to kill virulent airborne viruses, such as HINT virus, may also be toxic to humans or can at least instigate harmful side effects in humans. For example, the substances, intended to kill the germs, could at the same time trigger allergic reactions in humans.

For apparatus that are designed, to draw in airflow from ambient human-activity environments, such apparatus may inadvertently become collectors and breeding sites for germs. For example, electric hand dryers, that are installed in toilets, can draw in germs from the ambient atmosphere of the toilet.

This specification and its description contains several inventive aspects, and it is not intended that each and every inventive aspect should be able to solve each and eve - one of the above problems. Rather, each inventive aspect is able to overcome or at least ameliorate at least one or more problems.

Any discussion of prior art above and herein in this specification, either singly or in combination, is not to be construed as an admission of the state of common general knowledge of the skilled addressee.

Summary of .Invent ion

The present specification contains several aspects of the present invention:

According to a first aspect of flic present invention,, there is provided a Iniman-activity- environment air-purifying apparatus that draws in an. airflow from an ambient haman-activiiy- envixonment, kills germs in the airflow within the apparatus and expels the airflow purified back into the uman-activity-environme-nt, the apparatus comprising:

a housing having an. interior chamber into which an. airflow enters through, an inlet and from which interior chamber the airflow is expelled through an outlet;

an airflow-germ-killing-system adapted to kill germs in the airflow;

an airflow-generator which causes the airflow to flow from the inlet to the outlet;

wherein the airf ow'-germ-kiliing-system includes a gemi-kiliing-substance-eilfuser that effuses _.gemvkiltag-!iquid-substanee into the airflow,

and wherein the getni-ktlling-iiquid-subslance comprises at least one antimicrobial agent.

The at least one antimicrobial agent may be a quaternary ammonium salt.

The quaternary ammonium salt may be an alky! dimethyl benzyl ammonium chloride. The germ-kiliing-liqiiid-substanee may further comprise a second antimicrobial agent.

The second antimicrobial agent ma be a quaternary ammonium salt.

The quaternary ammonium salt may be selected from a dialkyl dimethyl ammonium chloride or an alkyl sily! ammonium film-forming compound.

The alkyl silyi ammonium film-forming compound may he selected from 3- trimeihoxysilylpropyl-N,N-dimethyl-N-oetadecyi ammonium chloride, 3-triethoxysilylpropyl- N, -dimethyl-N-octadecyl ammonium chloride, 3-triethoxysi1ylpropyl-N, -dimethyl-N-isodecyl ammonium chloride and 3-ttrmjethoxysi1ylpropyl-N,N-dmiethyl-N^sodecyl ammonium chloride.

The germ-kiliing-!iquid-substanee ma further comprise a third antimicrobial agent.

The third antimicrobial agent may be a biguamde The biguanide may be poly-hexamefhylene biguanide or polyaminopropyl biguanide. The germ-kilimg-liquid-substance may further comprise a disperser.

The disperser may comprise an aikylgJueoside or polyalkyiglycoside and/or an alcohol ethoxylate.

The germ-killing-liq«id-sa.bstance may further comprise an aqueous carrier.

The germ-killiiig-ljquid-substance may further comprise a solvent carrier.

The solvent carrier may be a glycol.

The glycol may be dipropylene glycol. germ-killing-liquid-substance may be a composition comprising:

an aikyt silyl ammonium ^'film-forming compound;

a bert alkoniuni or ben ethonium chloride;

a polymeric biguanide; and

a surfactant system comprising:

a. an alcohol ethoxylate; and

b. an alkylglucoside Or alkyipolyglycosidc.

The germ-kiliing-Hqaid-substance may be a composition comprising

an alky] silyl ammonium .film-forming compound:

a benzalkonium or benzethonium chloride;

a polymeric biguanide; and

a glycol carrier. in a preferred embodiment: the airflow-germ-kiUing-system includes a three-dimensional filter structure having air-filter-surfaces that define a filter interior region therei and eocompassed by the air-filter-surfaces of the filter structure, the encompassed filter iateoor region, in use, positioned in connection with the inlet so that airflow entering the inlet i dispersed into the interior chamber in, multiple directions exclusively through the air-nlter-surfaces of the three-dimensional filter structure,

wherein the air-fiUer-surfaces comprise multiple layers of different filler material, and wherein the multiple layers of the air-filter-suxfaces comprise a sequence of layers from nearest to the filter interior region to furthest from the filter interior region as follows:

i) a germ-killing filter layer thai carries germ-kiHrag-substaaec; and is.) a germ-kil ing-substance interception filter layer that intercepts or substantially intercepts the germ-kiUmg-subsiaiiee.

The germ-killmg-substancc-effuser may include a germ-killing-substance-sprayer that sprays the gcrrn-kilting-iiquid-substance into the airflow.

The gam-killiiig-s bstance-effuser may include a germ-lrilHng-substanee-f gger that iises ultrasonic vibrations to create a fog of the germ-killing-liquid-substance.

In a preferred embodiment: the germ-killiag-substaiice-cffuser includes a gerra-kiUing- substance-cai ridge that holds a fibrous matrix that is impregnated with the germ-kiiling-liqtiid- substance, and wherein the germ-killmg-substanee-cartridge is adapted, in use, to be attached to an exterior portion of the three-dimensional filter structure to enable the germ-kiiimg-iiquid- subsiance in the fibrous matrix to be exposed to the airflow emanating from the filter.

The gemi-killing-substance-effuser may be in the form of a wiek-delivery-system where the germ-kiili ng-liquid-substaiice effuses off a wick.

The gerrn-kiliing-liqiud-substance may have a characteristic of quaternary-microbe attraction when killing germs in the airflow.

According to a second aspec t of the present invention, there is provided use of a gerro- killing-liquid-sabstance in a human-acttvity-envtronmeni air-purifying apparatus that draws in an airflow from an ambient human-activiry-envkon ent, kills germs in the airflow within the apparatus and expels the airflow purified back into the human-aciivity-environment, the apparatus comprising;

a housing having an interior chamber into which an airflow enters through an inlet and from which interior chamber the airflow is expelled through an outlet;

an airflow-germ-killing-system adapted to kill germs in the airflow:

an airflow-generator which causes the airflo to flow from the inlet to the outlet;

wherein the airfiow-genn-kiliing-system includes a germ-killing-substance-effuser that is able to effuse germ-killing-Hquid-substanee into the airflow,

and wherein the genn-killing-!iquid-substance comprises at least one antimicrobial agent.

The at least one antimicrobial agent may be a quaternary ammonium salt.

The at least one antimicrobial agent includes a first antt microbial agent comprising alkyl dimethyl benzyl ammonium chloride and a second ami microbial agent comprising didecyl dimethyl ammonium chloride of an alkyl silyi film-forming ammonium compound. The germ-k tlling-Iiquid-sitbslaiiee may have a characteristic of quaternary-microbe attraction when killing germs in the airflow.

According to a third aspect of the present invention, there is provided a method of spraying at least one antimicrobial agent onto and. spreading the agent over a user's hands, the method comprising:

spraying a germ-killmg-liquid-snbsian.ee using a human-activity-environment air- purifying apparatus thai draws in an airflow from an ambient human-activity-enviforiment, kills germs i the airflow within the apparatus and expels the airflow purified back into the human- activity-environment, the apparatus comprising:

a housing having an interior chamber into which an airflo enters through an inlet and from which interior chamber the airflow is expelled through an outlet:

an airflow-germ-killmg-systeni adapted to kill germs in the airflow;

an airflo -generator which causes the airflow to flow from the inlet to the outlet;

wherein the airflow-genn-kiiling-systenv .includes a germ-kill mg-substance-effuser that is used to effuse the gerni-killing-hquid-substancc into the airflow,

and wherein the germ-ktllmg-liqiiid-substanee comprises at least one antimicrobial agent and a disperser,

and wherein the gernt-ktiling-iiquid-substance comprises at least one antimicrobial agent and a disperser, and the method includes using the airflow and the disperser to spread the at least one antimicrobial agent across the user's skin of the hands.

In a preferred em bodiment of the method, the airflow-germ-killing-system includes a three-dimensional filter structure having air-filter-surfaces that define a filter interior region therein and encompassed by the air-filler-surfaces of the filter structure, the encompassed filter interior region, in use, positioned in connection with the inlet so that airflow entering the inlet is dispersed into the interior chamber in multiple directions exclusively through the air-fiiter- surfaees of the three-dimensional filter structure

The at least one antimicrobial agent may be a quaternary ammonium salt and the disperser comprises an alkyl glycoside and or an alcohol ethoxylate.

The germ-kiliing-liquid-substance may comprise a first antimicrobial agent comprising alkyl dimethyl benzyl ammonium chlortde and a second antimicrobial agent comprising didecyi dimethyl ammonium chloride or an alkyl stlyl film-forming ammonium compound. The disperser may comprise one or more of decylghicoside, ociyiglucoside or capryl/caprylyl glucoside.

The germ-killirtg-iiquid-subslarice may comprise a third antimicrobial agent.

The third antimicrobial agent may be a biguanide.

The biguanide may be poly-bexamethylene biguanide or polyarainopropyl. biguanide. in the method, the gcm-killing4iquid-sub tmi.ee may have a characteristic of quaternary" .microbe attraction when killing germs in the airflow. According to a fourth aspect of the present invention, there is pro v ided a human-activity- environment air-purifying apparatus that draws in an airflow from aft ambient human-activity- environment, kills germs in the airflow within the apparatus and expels the airflow purified back into the human-aclivity-e dronment, the apparatus comprising:

an airflow-germ-killing-system adapted to kill germs in the airflow, the airflow-germ- killing-system including a three-dimensional filter structure comprising air-fiher-surfaces that define a filter interior region therein and encompassed by the air- filter-surfaces of the filter structure, the encompassed filter interior region, in use, positioned in connection with the inlet so that airflow entering the inlet is dispersed into the housing ^'interior chamber in multiple directions exclusively through the air-filter-surfaccs of the three-dimensional filter structure, the air-filter- surfaces comprise maitiple layers of different filter material, and wherein the multiple layers of the air-filter-surfaces comprise a sequence of layers from nearest to the filter interior region to furthest from the filter interior region as follows:

i) a germ-killing filter layer that carries genn-kiHing-substance; and

ii) a germ-killing-substance interception filter layer that intercepts or substantially intercepts the germ-killing-substance; and

wherein the apparatus comprises germ-kiiling-s^'ubslance-efFuser in the form of a germ- killing-substance-fogger that uses ultrasonic vibrations to create a fog of germ-killing-liquid- substance i the human-activity-environment about the air-purifying apparatus.

The germ-killing-liquid-substance may compris at least one antimicrobial agent The at least one antimicrobial agent may be a quaternary ammonium salt. The germ-k tlling-Iiquid-sitbslaiiee may have a characteristic of quaternary-microbe attraction when killing germs in the air.

According to a fifth aspect of the present invcniion. there is provided a human-activity- environment air-purifying apparatus that dravvs in an airflow from an ambient human-activity- environment, kills germs in the airflow within the apparatus and expels di airflow purified back into the human-activity-em roraoent, the apparatus comprising:

a housing having an interior chamber into which an airflow enters through an inlet and from which interior chamber the airflo is expelled through an outlet;

an airilow-germ-kilHng-s steni adapted to kill germs in the airflow:

wherein the airflow- -gemi-killing-systern includes a germ-killing-substance-sprayer that sprays germ-kiiiing-liquid-substaiice into the airflow,

and wherein the genn-kiliing-Iiquid-substance comprises at least one antimicrobial agent.

The at least one antimicrobial agent may be a quaternary ammonium salt.

The quaternary ammonium sait may be an alky! dimethyl benzyl ammonium chloride. The germ-killing-Hqaid-substance further may comprise a second antimicrobial agent. The second antimicrobial agent ma be a quaternary ammonium salt.

The quaternary ammonium salt may be selected from a dialkyl dimethyl ammonium chloride or an alk l silyl ammonium film-forming compound.

Drawings In order that the present invention might be more fully understood, embodiments of each of the aspects of the invention will be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a bottom perspective view of an embodiment of an air purifying apparatus in the form of a hand dryer, where the dryer is viewed at an angle from be!ow when the unit is mounted on an upright surface, such as a wall;

Figure 2 is a side vie w of the embodiment of Figure 1 showing the apparatus with the housing in a closed arrangement;

Figure 3 is an end view or underside of the embodiment of Figure 1 viewed from beneath when the apparatus is mounted on a wall or upright surface; Figure 4 is a partial perspective view of the embodiment of Figure 1 shown with its hood in an opened arrangement; the draw ing of Figure 4 is regarded as a partial v ie in the sense that certain components, relating to a sprayi ng apparatus, have been omi tted from the drawing of the dryer in Figure 4, in order to show the tapered passageway that would otherwise be partially hidden by the presence of the spray ing apparatus;

Figure 5 is a front view of the embodiment shown in Figure 4, with the hood detached from the base plate. I n this drawing of Figure 5, in comparison to the partial Figure 4, the spraying apparatus is shown in front of the tapered passageway;

Figure 6A is a perspective view of a three-dimensional filter used in the embodiment in Figures 4 and 5;

Figure 6B is an exploded perspectiv e vie of the three-dimensional filter of Figure 6 A. and its tray supporting assembly;

Figure < C is a cross-section of a cut-away portion of the three-dimensional filter of Figure 6A;

Figure 6.D is another cut-away, perspecti ve view of the three-d imensional filter of Figure

6A;

Figure 6E is a cross-sectional plan view of the three-dimensional filter of Figure 6A, with a sub- view showing an enlarged portion;

Figure 6F is a perspective view of a modified alternative three-dimensional .filter that is larger in size compared to the filter of Figure 6A;

Figure 6G is a perspective view of a modification to the three-dimensional filter of Figure 6A in which the filter structure is provided with an external rack for carrying pieces of material to he effused into the airflow;

Figure 6GA is a perspective view of a .further modification to the three-dimensional filter of Figure 6A. in which the fdter structure is provided with an external rack for carrying a fibrous matrix cartridge that is impregnated, with anti-bacteria substance;

Figure 6GB is a view of the modification of Figure 6GA shown wi th the fibrous matrix cartridge fitted in place;

Figure 7 is a perspective view of an assembly of a fan housing with an attached tapered passageway, and also shows, attached to this assembly, a filter holder that mounts a filter, and a liquid container support that supports a container of liquid;

Figure 8 A is an exploded view of components that make up the filter holder and the liquid container support shown in. Figure 7; Figure 8B shows a modification of the filter holder of Figure 8A in which multiple tin id reservoirs with wicks are provided;

Figure 9A is a side view of a first. exemplary variant of a pump mechanism used in the embodiment -shown in Figure 5;

Figure 9B is a perspective view of the variant of Figure 9A;

Figure 9C is an u derside view of the variant of Figure 9A;

Figure 9D is an exploded perspective view of the variant of Figure 9A;

Figure 10 is a cut-away perspective view showing an example of a modification of the spray pump mechanism:

Figures 1 1A and 1 IB show side views of part of the modified spray pump mechanism o

Figure. 10;

Figure 12A to 12D show a sequence of diagrams indicating movement of the modified spray pump mechanism of Figure 10 ;

Figure 1.2E sh ows a modi fication to the modifi ed spray pum p mechanism of Figure 10; Figure 13A. is a perspective view of the pump-spray motor and rocking arm used in. the embodiment of Figure 10;

Figure 13 A is a side view-' of the rocking arm of Figure 10;

Figure 14A is a partial perspective end view of a further embodiment viewed from beneath when the apparatus is mounted on a wall or upright: surface 3, where the modified external casing relates to the modifications shown in Figure 10 to 12F;

Figure 14B is a similar viewpoint to Figure 14A but showing another embodiment in which the nozzle is fixed in place and does not, in use, reciprocate back and forth;

Figure 14C is a side view of the modified embodiment of Figure 14B , where Figure 14C has cut-away portions to reveal internal components of the modified pump mechanism;

Figure 15A is a side view, and Figures 15B and ISC are perspective view of a further embodiment;

and the following drawings relate to a further modified embodiment of m air purifying apparatus in the form of a hand dryer which has two air intakes, where:

Figure 16A is a bottom perspective view- of yet another embodiment of an air purifying apparatus in the form of a hand cleaner-dryer, where the cleaner-dryer is viewed at an angle from below when the unit is mounted on an upright surface, such as a wall;

Figure 16B is another perspective view of the embodiment of Figure 16A, shown notkmally mounted on a wall, with its cover opened to reveal internal components;

Figure 16C is an exploded perspective view of the embodiment of Figure 16A; and Figure ! 6D is a front partial view of the embodiment of Figure 16A shown with the cover removed to allow a view of parts of the internal components;

Figure 17A is a front partial view of a further embodiment which is a modification of the embodiment of Figures I and I6 A in that the present embodiment of Figure 17A is provided with angled inlet apertures;

Figure 178 is a bottom, perspective view o f the embodi ment of Figure 17 A;

Figure 18 is an variation of the 'invention embodied in a vacuum cleaner;

Figure i A and 19B both relate to prior art, and are schematic diagrams of end o underside view s a prior art hand dryer or air purifier viewed from beneath when the apparatus is mounted on a wall or upright surface (with these views corresponding to the view in the embodiment of Figure 3 of the present invention);

Figure 20 is an end view or underside of a modified embodiment viewed from beneath when the apparatus is mounted on a wail or upright surface, where the modification is the provision, of a fogging device;

Figure 21 is a perspective, cut-away view of internal components of {he fogging device of Figure 20 showing how the fogging device is connected to the internal reservoir and its reservoir shell 7 1 , and showing ho the fogging device is activated by the eccentric drive and the rocking arm; and

Figure 22 is a cut-away, detailed view of a portion of Figure 21. showing sections of the fogging device in greater detail.

In the embodiments, like components are labeled with like reference numerals merely for the sake of ease of understanding the different embodiments and modifications of the various aspects of the invention.

In the description, the reference numeral 200 refers to the airflow, and this numeral with various suffixes 200A, 2.00B, 200C etc, refer to earlier or later portions of the same airflow that moves through the apparatus, and are not intended to refer to separate independent airflows.

Some of the further embodiments, described below, may comprise a partial modification in only sonic, but not all, of the components illustrated in an earlier-described embodiment of the invention in this specification. eserip doii o Embodiments Referring to the accompanying drawings. Figure 1 shows an embodiment of an air purifying apparatus in the form of a hand dry er 3 .

in Figure 1 , the dryer 1„ in use, draws in an airflow 200A from a human-activity ambient environment that is frequented by people, and then to expel that purified airflow 20OC back into the ambient environment The airflow 200 A is drawn in through an inlet in the form of an inlet aperture 101. The airflow 2(K)C exits the dryer through an outlet in the form of an exit-aperture 14.

The invention is not limited to a particular visual appearance of an inlet aperture and outlet aperture, and may be varied in accordance with other embodiments and modifications.

Examples of human-activity ambient environments, that are frequented by people, include toilets, doctors^'" waiting rooms, washrooms, rooms in a hospital, rooms for children, rooms for invalids, rooms in homes, to name but a few non-limiting examples.

Such human-activity ambient environments can also include closed environments that experience a high throughput of people such as waiting rooms, elevators, and in public transport such as trains and buses. Di fferent embodiments of the invention are not limited to hand dryers, but may include apparatus of different varieties that can incorporate an air purifying function for a range of human-activity ambient environments.

In Figure ] , the hand dryer \ is adapted to expel from the dryer 1 an airflow of

substantially sterilised air 200C that can be used, .for example, for drying hands. In the exemplary embodiment, the operational range of the heated air may be around 55 to 65 degrees Centigrade, although other embodiments may use whatever temperature is suited for that particular

environment. For example, winter climates may require airflows 00C of higher temperatures, white in warmer or tropical climates it may suffice for the dryer 1 to expel an airflow of lower or cooler temperature for drying hands in such warmer climates. The temperature of the airflow- may be adjusted to achieve a comfort-level, relative to the ambient temperature, for the user whose hands are exposed to the airflow. In other embodiments that are solely intended to function as air purifiers, no specific heating of the airf ow is required.

The hand dryer 1 has a housing. The housing includes a main hood 10 and a base- mounting in the form of a baseplate 1 1. The baseplate 11 is visible when the dryer 1 is in an open, partial view of Figure 4. The baseplate 1 1 is partly visible when, the dryer 1 is in a closed arrangement in the side view of Figure 2,

In Figure 2 and Figure 4, the hood 10 is mounted to the baseplate 1 1 by hinges 12. When the dryer 1 is installed in place for use, the basepla te 1 1 is secured to a wall or upright surface with screws, bolts or other appropriate fastening mechanism. Figure ! shows the hood 10 arranged in a closed arrangement, which is the arrangement of the dryer 1 when installed in location.

Figure 4 shows the hood 10 arranged in art opened arrangement

In the embodiment, the hood 1 and the baseplate 11 of the housing define therein an interior chamber in the form of inner chamber 13, The inner chamber 13 is the interior space that is enclosed by the hood 10 and baseplate 1 1. Figure 5 shows a range of components installed within the inner chamber 13.

Further embodimen ts are not limited to the shape , configuration or size of the housing 1 shown in Figure 1 , and the housings of other embodiments may vary in shape and configuration and many be greater or smaller in size.

During use, when the dryer 1 is operated to dry a user's hands, air from the ambient human-acti vity environment, in the form of an airflow 200 A, is drawn into the inner chamber 13 of the housing 1 where the airflow is purified, and may be heated. The airflow is subsequently expelled onto the user's hands in the outgoing stream 2O0C of the airflow.

The dryer 1 has two kinds of users of the apparatus: firstly the users who rely on the dryer

1 to dry their hands and to kill germs in order to purify the air in the ambient environment, and secondly the users who maintain the dryer by installing and replacing consumables inside the dryer 1. it is believed that the context of each situation will make it clear as to which user is being described.

in the embodiment of Figure ί , the incoming airflow 2.00A is sucked into the hand dryer

1 through the inlet aperture i 0 i .

When the hand dryer 1 is closed, as in Figures 1 and 2, the interface of the hood 10 and baseplate 1 1 is sealed to prevent ingress of airflow, other than through the iniet aperture 101. The air-proof seal between the contact surfaces of the hood and baseplate may be created by a rubber gasket material, resilient polymer, or other form of material that is capable of providing such an air-tight seal

In Figures 1 and 10, the inlet aperture 101 includes a grille structure 102. The grille Structure 102 comprises a grid-like arrangement of rods or strips.

When the dryer is closed and in operation, the incoming airflow 200A enters the hand dryer I through the inlet aperture 101. For the purpose of illustration only, however. Figures 4 and 5, which show an opened arrangement, nevertheless indicate the incoming 200A and outgoing 200C airflow as if the dryer 1 were notionaliy closed and in use. Also, in actual use, the airflow that occurs inside and through the dryer 1 has a degree of turbulence. Fan. in Figures 4 and 5, the airflow 200 A, 200B, 200C through the dryer 1 is created by airflow-generator in the .form of a. fan having a rotating fan-blade (not shown). The fan-blade revolves inside a fan-easing 400. Rotation of the fan-blade generates the airflow 200. The rotation of the fen-blade is operated by a fan-motor 405. The fan causes the airflow to flow from the inlet to the outlet. The invention is not limited to a particular shape of fan-blade.

In the embodiment, the fan, which is housed inside the fan-casing 400, is preferably a dual-fan comprising two fan-halves which together are adapted to draw airflow into the fan- casing 400 from two opposite directions.

In Figure 5, the dual-intake fan draws airflow into the fan-casin 400 from either side of the casing. Having two inlet apertures into the fan-casing 400 provides for a greater rate of airflow into the fan-easing 400, than would be the ease with a single aperture.

Hence, in Figure 5, part of the airflow enters the fan-casin 400 through an aperture located in one side 401 A of the casing. Another part of the airflow enters through another aperture in the other side 40 I B of the casing 400.

The fan is rotated by a fart-motor 405 that is at least partially housed in a motor-housing

403.

Part of the airflow, entering the other side 401B of the fan-casing 400, make ks way to the fan through a number of holes 402 located in the motor-housing 403. As the air enters through the holes 402, the air comes into contact or into proximity with parts of the fan-motor 405, and the airflow is heated to an extent by heat generated from the fan-motor 405.

Another part of the airflow, entering the other side 401 B of the fan-easing 400, makes its way to the fan through, a gap 407 A between, an adjacent outer surface of the fan-easing 400 and the motor-housing 403,

Air Heate in Figure 1 , the dryer 1 may be provided with heating-apparatus in the form of a heating element, in Figure 4, the heating element is located in a vicinity 20 downstream of where the airflow leaves the fart-casing 400. The heating element includes a grid of wires or plates adapted to be heated electrically when the dryer 1 is required to emit a heated airflow.

The heating element heats up the airstream 200B so that the expelled airflow 200C is Sufficiently warm to dry the user's hands. in other modified embodiments, there may be no need for a separate heating-apparatus. For instance, when the dryer 1 is used in countries with warmer or tropical climates, an airflow thai has been warmed merely by heat from, the fan-motor 405 may be sufficient to dry the hands comfortably for the user. Alternatively, where the hand dryer 1 is used in colder climates or where the ambient temperature is colder, a separate heating-apparatus, in addition to the heat from the fan-motor, may be provided.

Moreover, in other embodiments, which are not designed as hand dryers, but rather designed to function primarily or solely as air purifiers, in such embodiments there may be no requirement for a separate heating-apparatus over and above whatever heating may occur as the airflow passes through or proximate the fan-motor 405.

Genn ilhjng^y^m

In the embodiment of Figure \ , the hand dryer 1 is provided with airflow-genrt-kilHng- system. The airflow-germ-killing-system is in a form that includes one or more germ-killing subsystems. These airflow-germ-killing-systcm sub-systems, either individually, or preferabl in combination or combinations, serve the purpose of killing germs in the airflow. Description of embodiments of these one or more sub-systems of the airflow-gerat-killing-systera are provided below, by way of example only.

in the embodiments, various sub-systems of the airflow-gertn-kiiling-system preferably are. adapted to enhance airflo through the dryer 1.

I the embodiment of Figures 1, 4 and 5, a sub-system of (he airflow-germ-kiiling-system comprises a three- dimensional filter structure in the form of a three-dimeiisioiial filter 410A. The phrase "three-dimensionai filter structure" is used to distinguish it from another type of filter that consists of a generally two-dimensional, flat, planar sheet of filter material.

in this specification, the term "three-dimensional fitter structure" excludes and should not be construed to refer to microscopic features of the filter, for example, such as would require a microscope to readil discern. For example, the term "three-dimensional filter structure" does not cover microscopic gaps between individual strands or threads in the filter fibre. Hence, in this specification, the term "three-dimensional filter structure" is intended to relate to engineering design characteristics of a part of the apparatus, such as shown in the non-limiting examples in the drawings.

in the embodiment of Figures 4, 5, and 6A io 6E, as an example, the three-dimensional filter 4 ! OA comprises air-filter-surfaces that define an. encompassed filter interior region in the form of a filter interior 41 1 that is encompassed by the three-dimensional surfaces of the filter 41 OA.

In the embodiment, by way of example, the three-dimensional filter 4 ! OA is shaped as a container or a box having an opening 412 at one side. The three-dimensional filter 41 OA has semi-circular ends 413. In the embodiment, the filter interior 413 is an encompassed space or region which is bounded by {he air-filter-surfaces of the three-dimensional filter 41 OA, and which has the opening 412 at one side.

The sectional cut-out view of Figure 6D shows that the three-dimensional filter 41 OA is formed as a container or a box with one side 412 fully opened.

In this embodiment of the filter of Figures 6A to 6E, one entire side of the filter 410A is an opening 412, but in other modifications, the extent of the opening can be varied in terms of how much of the side is left open. For instance, in other modifications, merely part of a side may^¬ be opened, or portions or more than one side may be opened. In other words, other embodiments are not limited to a configuration where only one complete side is fully open

in u e, the three-dimensional filter 410A in Figure 4 is positioned in connection with the inlet aperture, which inlet aperture 101 is seen in Figures 1 and 3. In the embodiment, the filter 41 OA is positioned over the inlet aperture 101 so that ail of the airflow 200A, that enters into the dryer I through the inlet aperture 101 , first enters through the open side 412 and into the filter interior 411 , and then passes through the air-filter-surfaces of the three-dimensional filter 41 OA, and then is dispersed into the of inner chamber 13 of the hand dryer i . i f is through the open side 412 that the airflow 200A, from the inlet aperture 101 , is able to How into the filter interior 41 1 of flic three-dimensional filter 410A.

In other modifications, there may be an internal passageway that connects the three- dimensional filter 41 OA to the inlet aperture 101, however, such internal passageways are not open to the main chamber 13, since the airflow can only enter the main chamber 13 after it has passed through the three-dimensional filter 41 OA,

In Figures 6 A and 6E, the air-filter-surfaces of the three-dimensional filter 41 OA are i n a form that comprise wall-structure. In Figures 6A. and 6E, the wall-structure is in the form that comprises upright, side filter walls 414. The air-filter-surfeees are in a form that also comprise ceiliag-siracture. Figure 6A, the ceiling-structure is in the form of a filter ceiling 415. The filter ceiling 415 has semi-circular ends. The side filter walls 414 depend from the rim of the filter ceiling 41 . ^'Hence the semi-circular ends of the ceiling 415 correspond in shape to the semi-circular ends 413 of the walls 414.

Referring to Figure 6A, the filter ceiling 415 has a ceiling-frame 41.5A, The side filter walls 414 also have a wall- frame 14 A . In manufacture, the ceiling-frame 415 A may be connected to the wall-frame 4.14A by any suitable joining mechanism, such as through sonic welding or by the use of adhesives to bond the frames 415 A, 414A together, or ^'through the use of meeft anic al connections.

I |he embodiment of F igu re 6D, the opening 412 has general ly the same struc tural sh ape as the filter ceiling 415.

in the embodiment of Figure 6D, the side filter walls 414 are generally perpendicular to the plane of the filte ceiling 435.

in Figure 6 A and 6E, the side filter wails 414 and the filter ceiling 415 combine to define therein the filter interior 411 that is encompassed by the three-dimensional surfaces of the filter 41 OA.

In the embodiment, the three-dimensional nature of the filter 41GA means that it has an encompassed internal volume, having height, length and breadth, which together define the fiher interior 411 within the body of the filter 41 OA. The height of the filler walls 414 determine the height of the filter 41 OA. The filter interior 41 1 has a three-dimensional encompassed volume. This is distinguished from a generally flat sheet of filter material which, tn this specification, is not regarded as three-dimensional, having no encompassed interior space defined by height, length and breadth.

In other modifications, the three-dimensional nature of the filter may be such that the wall-structure and ceiling-structure are part of a seamless, contiguous structure, such as a dome or mound. In even further modifications, the three-diraensioaal nature of the filter may be such tha the wall-structure and ceiling-structure are also a contiguous structure, such as a pyramid, cubic, or tent-shaped structure, even having rectangular sides, for example, in all these modifications, the modified three-dimensional filter w on Id include an encompassed filter interior that has a three-dimensional volume, in other modifications, the open side 412 may alternatively be circular, square-shaped, rectangular, oval, or any suitable regular or irregular shape.

In use of the embodiment of Figure 6D, the airflow 2 0A enters the dryer 1 through its inlet aperture 101 , and then the airflow passes through the opening 412 of the three-dimensional filter 1 OA and into the filter interior 11, The air in the filter interior 41 1 is drawn through both the filter ceiling 415 and the upright filter walls 414. Thus, the airflow is dispersed in multiple directions exclusively through the wall and ceiling parts of the air- filter-surfaces of the three- dimensional filter 41 OA. The airflow 200A is dispersed in multiple directions, for example in the embodiment, by being dispersed straight through the ceiling 415 portions, and also dispersed laterally through the upright, side filter wails 414,

in modified embodiments where the three-dimensional filter structure is in the form of, for example, a dome, pyramid or tent, whether regular or irregular-shaped in each ease, the air- filter-surfaces, that are arranged in substantially different orientations, enable the airflow to be dispersed in multiple directions. This is in contrast to airflow that disperses through a flat, sheet- like planar filter in a generally consistent uni -direction,

Compared to a scenario of using a flat, two-dimensional filter to span the inlet aperture 101 , in contrast, the three-dimensional filter 41 OA of the present embodiment has a total combined surface area of the air-filter-surfaces, comprising the ceiling 4.15 portions and the upright filter wails 414, that provides a substantially and significantly larger surface area for the ai rflow 200.A to enter the dryer 1. The larger effecti ve surface area of walls and ceiling of the three-dimensional filter 4! OA enables a larger volume of airflow to pass through the filter 41 OA,

A greater filter surface area offers a larger air-transmission area, through which the airflow 200A can pass through the three-dimensional filter 410A.

Without being limited by theory, it is believed that the provision of a greater air- transmission surface area equates to less resistance to the airflow, it is believed that, for a given amount of air that needs to pass through the filter, a filter provided with a greater air-transmission surface area would offer less resistance to the airflow.

Without being limited by theory, it is believed that havin less resistance to the airflow may allow a less powerful, fan-motor to be used to achieve the required rate of airflow through the hand dryer 1. Less powerful fan-motors, that drive the internal fan, may be linked to a lower degree of noise during use.

Alternatively, the lesser resistance to airflow may be utilized in a different manner, which is to use a more powerful fan-motor to achieve faster rates of airflow than would be possible without such a three-dimensional fil ter, in this regard, in the example of the hand dryer 1 , the fan- motor is preferabl a universal motor with a rated speed of 13,000 to 14,000 rpm, which is generally suited for intermittent, stop-start operation. In the example, this higher speed motor configuration provides a very fast throughput of airflow which reduces the time needed for a user to dry his hands. Dry in times of less than 11 seconds ha ve been a chie ved in experimental embodiments, whereas in the marketplace drying times of double that, around 20 seconds, are often considered acceptable.

Another advantage of the provision of greater surface area of such a three-dimensional filter is that it is able to last longer in use before needing replacement, compared to a filter that had less surface area. A filter with greater surface area would tend to take longer to reach a point of being clogged u and needing to be replaced.

Another advantage is that the three-dimensional filter, with its larger surface area compared to a fiat two-dimensional filter, may offer a greater surface area that can potentially cany a larger amount of anti-germ substance.

Another advantage is that, if all other factors were equa a filter wi th greater surface area results in lesser resistance to airflow, which ma tend to increase the lifespan of the fan-motor.

Filter _.Surface_^ S_.traciure in the embodiment of Figure 6^'D, the air-filter-surfaces may comprise a three-dimensional surface structure that is non-fiat. In this specification, the phrase "non-fiat'" is not intended, and should not be construed, to refer to the microscope thread or strand filter structure that would be discernible by a microscope. For instance, a piece of paper is regard as having a flat surface structure, even though under a microscope it would not. Hence, in this specification, the term "non-flat" is to be construed from the same perspective as viewing all the engineering design components as shown in the non-limiting exemplary drawings.

In the embodiment, the non-fiat surface structure may be a multi-faceted surface structure. The multi-faceted surface structure further provides a larger effective surface area compared to a totally fiat, sheet-like surface. A larger suriaee area offers a greater surface area through which airflow can pass through the filter.

In the embodiment of the filter in Figures 4, 5 and 6A to 6E, the multi-faceted surface structure of the air-filter surfaces may be an undulating structure. The undulating structure may be in a form that has a pleated, corrugated_* rippled or .zig-zag-shaped structure, any of which would distinguish the undulating surface structure from totally flat sheet material. The undulations may have sharp edges, as shown in example of Figure C , or the undulations may ha ve curv ed or gently-contoured edges. In other words, the term multi-faceted in this specification includes, but is not limited to, a case where each of the facets is fiat, as in the analogy of diamond facets. in Figure 6C, the multi-faceted surface structure comprises a corrugated or pleated structure, which are two alternative descriptive terms to describe tlx^* same structure shown, in Fi ure 6C.

In other modifications, the multi-faceted surface structure may comprise either a random or orderly, regular or irregular, pattern of three-dimensional bumps or protrusions on the surface of the three-dimensional filter structure. Such, three-dimensional bumps or protrusions would likewise have an effect of increasing the available surface area of the filter through, which, air can flow, compared to the surface area of a flat, sheet-like surface of similar length and breadth.

In the embodiment of Figure 6C, the cross-section of both the ceiling 415 portions and the upright filter wails 414 have a corrugated or pleated structure consisting of alternating ridges 416 and groo ves 417. The ridges 416 have sharp edges along the length of the ridges. In other modifications, the ridges may have more gently-contoured, curved or rounded edges. For example, in other alternative embodiments, the multi-faceted, three-dimensional surface structure may include a corrugated structure where ridges and grooves are less pronounced, with the structure resembling an undulatin wave-like structure.

Although the embodiments of surface structure shown in the illustrated embodiments comprise a regular three-dimensional surface structure, other modifications may comprise an irregular three-dimensional surface structure.

Figure 1.0 shows a cross-sectional, cut-away vi ew of the three-dimensional filter 41.0 A of Figure 5. A difference between the apparatus in each of Figure 5 and Figure 10 is that the former incorporates a .first embodiment of a pump spray apparatus 700A, while the latter incorporates a second embodiment of a modified pump spray apparatus 700B (the pumps described below).

In other modifications, the Overall shape and size of the three-dimensional filter structure can be varied. For example, a modified embodiment in Figure 6.F shows a larger three- dimensional filter 41 B that has a modified overall shape thai is different to the filter used in the earlier embodiment in Figure 4. fit the modification in Figure f>F, the three-dimensional filter 41 OB has corrugated wails 414B and ceiling 415B that have a somewhat more orthogonal three- dimensional structure, without the pronounced semi-circular ends 413 of the earlier embodiment of the filter of Figures 4, 5, and 6A to 6E.

For the sake of clarification, although the microscopic structure of the filter material may comprise interwoven fibres that, in other contexts, are regarded as three-dimensional, instead, in this specification, the three-dimensional nature of the filter, and also the nature of its filter surface structure, are regard here as being three-dimensional by having with regard to its overall design maefostructiire as shown in the appended drawings, rather than its microstfueture. Filter Insertion

In the embodiment of Figures 4, 5 and 6B, and in the filter shown in Figure 10, the three- dimensional filter 41 OA is able to be seated on a tray- structure. The {ray-structure is in the form of a tray-frame 424 tha t has semi-circular ends 425, such that the shape of the tray-frame correlates with the cross-section shape of the three-dimensional filter 41 A that is able to be seated on the tray-frame 424. The shape of the plan view of the tray-frame 424 corresponds to the shape of the base of the three-dimensional filter 1 OA

In Fi ure 6B and Figure i 0, the tray-frame 424 has an open central region 428, The open central region 428 is traversed b a grille structure 426. The grille structure 426 comprises an arrangement of crisscrossed rods that span from one side of the frame to the other in a grid-like arrangement. In Figure 6B, the ends of the rods, of the grille structure 426, are supported by the tray-frame 424. in the cross-sectional view of Figure 10, a sectional view of the tray-frame 424 is shown wit the three-dimensional filter 410A seated thereon.

in Figure 6B, the tray-frame 424 has a peripheral rim 429, When the filter 41 OA is seated on the tray-frame 242, the rim 429 prevents the filter 41 OA from moving from side to side when the airflow 200A passes through the filter 410A,

In the embodiments of Figures 5 and 10, the tray-frame 424 is able to slide into place in the hand dryer 1 , with the base of the three-dimensional filter 410A attached to the tray-frame 424.

In Figure 0, the tray-frame 424 has a base portion. The base portion has lateral sides that are each provided with a pair of elongated, outwardly projecting strips 427 that, in use, are able to slide in corresponding elongated grooves in. the hand dryer 1, Slotting of the strips 427 into the grooves serves to anchor the three-dimensional filter 41 OA in order to provide resistance to the force of the airflow thai flows through the filter 41 OA during operation of the hand dryer 1.

When the filter 41 OA needs to be replaced, the tray-frame 424 is slid out of place, a replacement filter attached to the tray -frame 424, and the tray-frame slid hack into place in the hand dryer 1 . Thus, the three-dimensional filter 41 OA, 41 OB in its various embodiments, which is seated on the tray-frame 424, is able to be replace bly slid into position.

MULTI-LAYER FILTER in the embodiment, in Figure 6D, a further sub-system, of the overall ajrilow-germ- killing-system, relates to the air-fiHcr-surfaccs that comprise multiple layers of different filter material. The multiple layers of the air~fitter~surfaees are seen in the cross-sectional view of

Figure 6C.

The cut-away, cross-sectional drawings of Figures 6C and 6D show that the ceiling 415 portions and the upright filter walls 414 are each made up of multiple layers. Each of these layers comprises a different filter material with distinguishing characteristics. Each of the different layers of filter material perform a different function.

In the embodiment, the layers of different filter material are ordered in a certain sequence, because adjoining layers perform roles that depend on. the order of the layers in the sequence of layers.

in the embodiment in Figure 6.D, in the upright filter walls 414 and in the ceiling 415 portion, there is a first layer 418, a second layer 19, and there may be at least a further third layer 420. The layer-sequence will be described, starting with a description of the filler that is nearest. to the filter interior 411 , and then proceeding to the filter that is next furthest away from the filter interior 41 1 . The first 418, second 41 and the preferred third filter layers 420 are shown in tile cut-away drawing in Figure 6C.

The filters are described in that sequential order because, in the embodimen , the filter interior 41 1 is where the airflow 200A first enters the hand dryer 1 apparatus. Therefore, as the airflow 200A passes through the air- ilter-surfaces of the three-dimensional filter 41. OA, it is the first filter layer 418. of the layer-sequence, that makes initial contact with the airflow 200A.

First _.Layer I the sequence of layers, the first filter layer 418 comprises; a germ-killing filter layer in the form of germ-killing filter 418.

The expression, first layer, is used to describe the germ-killing filter 418 because this is the first layer of the three-dimensional filter 410A that, in use, initially encounters the incoming airflow 2 0A.

The incoming airflo 2G0A, which is drawn from a hitman-activity ambient environment, contains germs.

The first filter, the germ-killing filter 418, carries^' germ-killing substance. As the incoming airflow 200 A. passes through the first filter 418, germs in the airflow are killed in the first germ-killing filter 418. The germ-killin substance, carried by the first germ-killing filter 418, can be any suitable substance that. is adapted to kill genus in the airflow 200A. Examples of suitable germ- killing substances are as follows: Nano-TiOj, nano Si<¼ and nano ZnQ_?. An example of a filter material used for the first germ-killing filter 41 8 consists of: 77% polyester and 19%

polypropylene fibres, together with 2.6% ano-TiOj, 0,7% nano SiO? and 0.7% nano Zm¾. The embodiment is not limited to this particular type of filter, and other^' appropriate antibacterial filter material may be used.

It is appreciated, however, that embodiments of the taveatioa are riot limited to any particular germ-killing substances being carried in the germ-killing filter layer, and can be varied and adapted depending on the nature of germs thai are encountered in a particular ambient environment.

Second Laye The second layer 41 of the three-dimensional filter 41 OA is the second in the ^'layer- sequence thai the incoming airflow 200A encounters as it moves through the three-dimensional filter 41 OA.

The second layer 419 comprises a gemi-kiliing-substance interception filter layer that intercepts or substantially intercepts the geim-killmg-substanee th come from the first layer 418.

In the embodiment in. Figure 6D, the germ-killing- substance interception filter layer comprises a fitter layer that is impregnated with charcoal or carbon.

An example of a filter material used for the second layer 419 consists of a nonwoven mix of functional polyester and bonding bieomponent fibers with polyester core and co-polyester sheath, impregnated with ethylacryla e-vinylchloride-copolymer, poiyfosfate flame retardant, activated carbon powder and black pigment. The embodiment is not limited to this particular type of filter, and other appropriate carbon or charcoal-impregnated filter material may be used.

When the airflow 200A moves through the air-filter-surfaces of the three-dimensional filter 41 OA, a portion of the germ-killmg-substance may come off the first filter 418 and thus enter the airflow. Some germ-kitling-substance, which are deadly to germs, may likewise be harmful to humans. Hence, the carbon or charcoal in the second layer 419 intercepts any germ- kiiling substance that comes from the first layer 1 8. As a consequence, the second layer 419 prevents, o at least minimises, the amount of genn-killing-substanee that is allowed to be carried by the airflow into the inner chamber 13 of the hand dryer 1. The impregnated carbon or charcoal in the second layer 419 is also able to remove smells and odors from the airflow. For example, some germ-killing substance, that are needed to kill highly toxic germs, may themselves have matadors or smells. Hence, the charcoal may also remove or at least minimise the extent of those smells in the airilow that enters the inner chamber 13 of the hand dryer 1. Thus, as a result of the second layer 4 , the airflow that enters the inner chamber 13 is able to be substantially free ofmaiodours.

T rd Layer la the embodiment, the three-dimensional filter 41 OA may be provided with a third layer

420 which comprises; a material entrapment layer that entraps at least any filter material that come from or is released from the first filter layer 418 or from the second filter layer 41 .

In the embodiment, as the airilow 200A flows throug the first two filter layers 418, 419, microscopic fibers or particles, originating from the material from which the first 41 8 and second 419 filter layers are made from, may be released into the airflow 200 A. if these microscopic fibers or particles in the airilow were to be released in the outgoing airflow 200C that exits from the hand dryer 1 , then, once these are released into the ambient environment, these minute objects may cause irritation, for instance, in the nasal passages or eyes of people in the huma activity environment. Such microscopic fibers or particles ma he particularly irritating to people that suffer from allergies.

in the embodiment in this third layer 420, the material entrapment layer includes anti- fiber-migration filter material. The material entrapment layer includes a fiber material that is able to entrap the said material that may emanate from the first 41.8 and second 419 filters.

An example of an anti-fiber-m igration filter material comprises a polyester fabric of greater than 85% polyester component, and less than 15% binder resin. The third layer 420 of the embodiment is not limited to this particular filter material, and other suitable materials may be used based on their abili ty to intercept said material that may emanate from the first 4.18 and second 419 filters.

In other modified embodiments, the first, second and third layers may be embodied, not merely as discrete layers, but alternatively may be in the form, of functional layer-regions. For instance* a modified embodiment may have tw or more initial sub-layers that both perform the function of killing germs, in this example, the two germ-killing sub-layers combine to form a first func tional layer-regions. Each of the sub-layers, in this first functional lay er-regions, ma carry a different germ-killing substance for killing different variety of germs. In other words, the first layer-region is not restricted to being just one layer, but may have two or more layers having similar functional characteristics.

Likewise, the second layer-region may have two or more layers each sharing similar functions.

Likewise, the preferred third layer-region may have two or more layers each sharing similar functions.

INTERCHANGEABLE ANTI-GERM MATERIAL

In Figure 6B, the airflow-gerni-kifling-system of the hand dryer 1 may optionally includes a further germ-killing sub-system that comprises genri-kiHmg-substarice positioner in the form of a mounting structure 421 , 422, 423. This gemi-killing-substauce positioner is a preferred feature that is not necessarily present in all embodiments.

The mounting structure is able to position one or more sources of one or more air- diffusible germ-kil ing- substances inside the filter interior 4! 1.

The air-dif fusible germ-killmg-subsiances are characterised in their ability to air-diffuse upon engagement with any airflow in the filter interior 41 1. Before air diffusion occurs, each of the one or more sources is initially in the form of a solid or gel. Then, when the airflow 200A flows over the air-diffusible germ-killing-subslances, the substances are diffused into the airflow, mostly by an evaporati on mechanism.

The mounting structure- includes tablets 421 that have an outer frame 422. In the embodiment;, the air-diffusible germ-kiilmg-substances is in the form of a block of gel that is carried inside the frame 422. The frame 422 has an internal mesh (not shown) that acts as a web that trarisverses the region within the frame 422. The gel is formed around this mesh. The mesh prevents the gel from falling off the frame 422,

In the embodiment:, the mounting structure also includes clasping mechanisms 423 located on the rods of the grille structure 426, The frames 422 are mounted on {he gri lle structure 426 b engaging with the clasping mechanisms 423.

Figure 6^'B shows, for example, three such sources of air-diffusible gemi-killmg- substanees in the form of air-diffusible anti-bacteria tablets 421 A, .42 IB, 421 C. in the embodiment of Figure 6B, the active germ-killing-substanee may be in the form of an air-diffusible gel In use, as the airflow 200A rushes over the tablets 421, the germ-killing- substanee on each tablet progressively diffuses in the stream of airflow 200A that rushes over the tablets, thus infusing the airflow with the germ-killing-substanee to kill the associated germs in the airflow.

Optionally, there ma be multiple sources whe re each of the tablets 421 A, 421B, 421C is provided with a different germ-killing-substanee that kills di fferen t types of germs.

A range of available air-diffusible germ-Mlling-substances may be used for the tablets 421 A, 42 IB 421 C, and their selection depends on their known properties for killing the type of germs in a particular ambient human-activity environment.

For example, in Figure 6B, there are shown three such tablets 421 A, 42 IB, 421 C, and these three tablets may each be carrying the same germ-killing-subsiance, or alternatively each of the tablets may each carry a different substance each designed to combat differen type of germs.

In the embodiment of Figure 6B, there is a synergy between the germ-killing first filter 418 of the three-dimensional filter 410 which, in this embodiment, acts in tandem with the optional air-diffusible anti-bacteria tablets 421 A, 42 IB, 421C.

On One hand, the first germ-killing filter 418 of the three-dimensional filter ma be suited for carrying germ-kill ing-substance for killing germs that are of a ubiqui tous variety, which are encountered week in week out. The germ-killing-substanee on the first layer, the germ-killing filter 418, is capable of lasting for a long time, such that the three-dimensional filter 410A tends not to have to be replaced frequently.

On the other hand, the optional mounting structure 421 , 422, 423 enables tablets to be interchanged and replaced as often as needed. This interchangeability also provides a degree of customization, which enables different germ-killing-substanee to be placed in position, or later replaced with other different substances. For example, epidemic-level germs, such as the SA S or HiNl virus, can tend to prevalent for a limited season. Hence, administrative operator of the hand dryer 1 can insert customized tablets 421 , as the need arises, to adapt and respond to newly discovered threats of emerging viruses.

Moreover, in a preferred embodiment, the ability to optionally mount the tablets 421 A, 421 B, 421 C, each having different germ-killing substances thereon, enables the administrative operators of the hand dryer 1 to utilize tablets carrying two or more different germ-killing substances so as to combat several types of major prevailing viruses at the same time, rather than being limited to using only one type of germ-killing substance at a time. Also, it is observed that the germ-killing substances, often needed to combat highly virulent viruses, such as the H1N1 virus, may also be toxic to humans. Hence, the abilit to position these human-toxic anti-bacteria tablets 421 A, 42 I B, 421C inside the internal fil ter interior 4.1 1 of the three-dimensional filter 4 IDA means that any human-toxic substances, diffused off the tablets 421 into the airflow 200A. may be intercepted by the second layer 419 of the three- dimensional filter 41 OA.

It is noted that these tablets 421 A, 42] B, 421C ideally would not be used to cany fragrance or perfume since these substances would be trapped or intercepted by the charcoal layer in the second filter 419, thus nullifying the influence of the fragrance in the airflow 200C emitted from the dryer 1 back into the human activity environment.

Figure 6G is a perspective view of a modification to the three-dimensional filter of Figure 6A in which the filter structure is provided with an external rack 430 for carrying pieces of preferably fragrance-effusing material 431 to be effused into the airflow. The fragrance material is placed outside of the three-dimensional f ilter 4 IDA so that the fragrance material is not intercepted by any of the layers of that filter 41 OA, particularly the second layer which is impregnated with carbon or charcoal.

Wick In. the embodime n t of Figure 7 , the airflow-germ-killing-system o f the hand dryer 1 may optionally include a further germ-killing sub-system that comprises germ-kil ing-substance- effuscr in the form of a wick-deli very-system.

I the embodiment of Figure 7, the wick-del ivery-system is in a form of a wick filter arrangement 612 that includes an air wick 600, The air wick 600 is able to effuse an anti- bacterial, germ-killin liquid that is stored in a replaceable container. The replaceable container is in the form of one or more replaceable bottles 610.

In Figure 7, part of the airflow enters the fan-easing 400 through the aperture thai is located in. the one side 401 A of the casing which is located further away from the motor-housing 403, The air wick 600 is positioned in front of the aperture in the side 401 A of the fan-easing 400 which is located further awa from the motor-housing 403.

The air wick 600 is arranged so as to be dipped in the liquid that is inside the bottle 610. As airflow 200 in the inner chamber 13 flows past the wick.600 as it enters the fan-easing 400, the liquid in the bottle 1 is drawn up through the wick and is dispersed into the airflow as it enters the fail-easing 400. in the embodiment of Figure 7, the wick filter arrangement 612 also includes a filter holder 61 1 that is able to support a further germ-kiliing-substanee interception filter layer in the form of wick filter arrangement 612.

The wick filter arrangement 612 may comprise one or more layers of filter that performs a similar role to the second layer 419 of the three-dimensional filter 410, namely to intercept or substantially intercept the genn-kiliing-substance in the airflow that comes from the wick 600, before the airflow enters the fen-casing 400. For a non-limiting example of a filter material useable with this filter holder 61 1 for interception of germ-killing substances, see the example given above use with for the second layer 419 of the three-dimensional filter 1 OA, since the func tion of bot of these filters is to intercept germ-killing substances.

Figure 8A shows an exploded view of the wick filter arrangement 612, comprising the wick 600 that is attached to the bottle 610, the filter 613, and the filter holder 6 1. The filter holder 1 .! has a pai of resilient pincers 614 that are adapted to hold the neck of the bottle 10. The filter 613 is provided with a slot 615 that fits over the pincers 614. When assembled, the bottle 610 is held by the pincers, and the filter is held by the pincers.

The wick filter 61 is also able to intercept moisture in the airflow, for instance any moisture emanatin from the wick 600, so as to minimise the likelihood of moisture bein in the air by the time the airflow reaches the optional heating element, in the embodiment, as mentioned, the optional heating element is located in the vicinity 20 downstream of where the airflow exits the fan-casing 400.

in other .modifications, the filter holder 11. may also support a further material entrapment layer that performs a similar role to the third layer 420 of the three-dimensional filter 410, namely to entrap at least any filter material that come fto.ni the material of the wick filter 13 , For a non-limiting example of a filter material useable with this further material entrapment layer, see the example given above use with for the third layer 420 of the three-dimensional filter 1 OA.

Figure 8B shows a further modification where multiple fluid reservoirs 610 with wicks 600 are provided. Having^' multiple reservoirs enables a user to infuse a wider range of materials into the airflow. For instance, one bottle may contain an anti-germ or anti-bacteria fluid, while the other bottle ma contain a fragrance liquid.

In a further possible modification, the wick 600 and bottle 610 may be placed inside the .filter interior 4.1 .1 that is within the three-dimensional surfaces of the filter 410A, 410B. in such a modification, the three-dimensional filter 410A_T 10B is made of sufficient size to accommodate the wick and bottle within. An advantage of such an embodiment is that any harmful substances, distributed by the wick, can be subsequently intercepted by the charcoal, filter ^'material in the second layer 41 of the three-dimensional filter 41 A.

The embodiment in Figure 5, in contrast to the modification in Figure 7, omits the wick 600 and bottle 610, indicating that the wick mechanism is a preferred feature that is not necessarily presen in all embodiments.

Examples of germ-kiMmg-suhstatiee in liquid form that can be delivered by the wick mechanism, include known available anti-bacterial liquids that can be effused into the air to kill germs, and the embodiment is not intended io be limited to any one type of substance for this purpose.

Selection of Different Options Of Delivery

In the exemplary embodiments, the air wick 600 in Figure 7 and the tablets in Figure 6B are preferred features.

The wick filter arrangement 612 in the exemplary embodiment of Figure 7 is useful for delivering substances that arc ideall delivered from a liquid soxircc, such that the liquid substance is stored in the bottle 6] 0 for delivery into the airflow via the wick.

The tablet system in the exemplary embodiment of Figure 6.B is useful for delivering substances that are ideally delivered from a solid source, such as a gel.

Hence, in various embodiments, the decision on whether to include a wick or tablet system may be influenced by the nature of substance that needs to be deli vered into the airflow, and/or depending perhaps on the nature of germs that need io be killed in a particular ambient human-activit environment.

SPSAY

In Figure 5, the airflow-germ-killing-system of the hand dryer 1 may optionally includes a further germ-killing sub-system in a form that may include germ-killing-substance-effuscr. Several exemplary, non-limiting variants of germ-killing-substance-effttser will be described below by way of example onl .

Spray Pump Variant 1 Figure 5 shows a gcrm-k»iljag-s«bstance-e:ffuser in the form, of a pump spraying apparatus 700A.

A function of the um spraying apparatus is to emit a brief burst of spray of antibacterial liquid into the airflow 2 0C that exits the dryer 1.

Although several embodiments arc described below, the embodiments of the in ven tion are not limited to any one of these exemplary spray mechanisms, since other variations can be proposed to achieve a similar pumping spray action. (In the partial illustration of Figure 4, the pump spraying apparatus 700A has been omitted from the cut-away diagram in order to show, in the illustration, die tapered passageway 16 which are located behind the pump spraying apparatus 700A when all assembled).

In Figure 5, the pump spray apparatus 700A introduces yet further gcrm-killing- substance, in the form of a liquid anti-germ, substance, to the airflow by sprayin the germ-killing substance into the airflow. The spray liquid, comprises an anti-bacterial germ-killing liquid, and may also include a fragrance liquid provided that there is no chemical reaction between the artfi- bacterial liquid and the fragrance substance.

Preferably, this further gcrm-ki!Ung-substance is sprayed into the airflow at a location where the genn-kiiiing-substance does not become coated on surfaces of the apparatus itself In the embodiment of Figure 5, the pump spray apparatus 700A is arranged, to spray the liquid anti- germ substance into the airflow at a point where the airflow has already exited the hand dryer 1.

In. the embodiment, the liquid anti-germ substance is sprayed in such a way that the anti- germ substance from the spray apparatus 700 A emerges through a spray-outlet in the form of spray aperture 758, and enters the airflow where the airflow is already outside the dryer 1 mingling with the ambient human-activity environment. The spray apparatus 700A sprays the anti-germ substance into the airflow that is already outside of the apparatus 1 so that the force of the airflow carries the substance onto the user's hands when the users expose their hands to the exiting airflow 20 C.

In other words, the anti-germ substance from the spray apparatus 700A is preferably not sprayed inside the apparatus 1 itself This is to minimise the likelihood of build-up of the sprayed anti-germ substance on internal surfaces of the dryer 1 , which could otherwise occur if the anti- germ substance were to be sprayed into the airflow while the airflow is still inside the dryer ! .

Alternatively, in a yet further embodiment, the Spray apparatus 700 A may spray the liquid anti-germ substance directly onto the user's hands, however, even in such a modified embodiment, the substance is spray ed in such a manner that it avoids or substantially minimises the substance reaching: and coating surfaces of the apparatus 1 itself. in the embodiment, the liquid anti-germ substance- may be a non-aicohol-based liquid, since it is found that the airflow around the person's hands, as the liquid is blown onto the hands, is sufficient to dry the liquid without the added effect of alcohol evaporation.

In other embodiments, if desired, the liquid anti-germ substance may be an alcohol-based liquid which is able to rely on alcohol evaporation to expedite drying of the liquid on the user's hands.

The liquid anti-germ substance, that the spray apparatus 700A sprays onto the user's hands, may be a mild antiseptic substance, and not a powerful toxic anti-germ substance which could inadvertently be toxic or irritating to humans.

In the embodime nt of F igu re 5, the pump spray apparatus 700A includes a pump ing mechanism that is able to be activated to emit a brief burst of spray.

in this first exemplary variant of the pumping mechanism, in Figure 5 and Figure 9 to 9D, the pumping mechanism includes a solenoid-driven pump mechanism. The hand dryer 1 is provided with a microprocessor and electrical circuit that is programmed to determine when to instruct and activate the solenoid 750A, 750B to drive the pump.

in Figure 9A, the pump spray apparatus 700 A includes a reservoir container 751 supported on a circular holder 752. The reservoir container 7 1 is able to hold a quantity of liquid such as an anti-germ substance in liquid form, in other modifications, the anti-germ liquid substance may also include a fragrance mixed into the aati-germ liquid.

In Figure 9D, the container 751 is provided with an exit nipple 753 which engages with a corresponding hole 754 in a nozzle cap 755. The nozzle cap 755 presses on an internal spring- loaded pump tube, whereb pressing on the nozzle cap 755 causes a pumping action. Each depression of the cap 755 draws Out an amount of liquid from the container 751. To emit several bursts of spray, the nozzle cap 755 is pressed several times for as many times as are required.

The hole 754 in the nozzle cap is connected via an internal channel to an exit nipple 756.

A thin tube 757 connects the exit nipple 7 6 to the spray aperture 758.

In Figure 9D, the solenoid includes two reciprocable components 750A, 750B. Activation of the solenoid causes the outer one of these two components 7508 to move so as to press against the nozzle cap 755. This pressing action causes an amount of liquid to be pumped out of the container 751 , through the internal channel, then through the thin tube 757, and finally to be sprayed out through the spray aperture 758. The spray aperture 758 is shaped to cause the liquid to be emitted as a fine mist of droplets of the liquid.

in Figure 9C, the exit-facia plate 1 is provided with a circular hole 759. The liquid sprays from the spray aperture 758 through this circular hole 759. in Figure 9C, the exit-facia plate 15 is provided with an aperture 19 that enables sensors 17 to have a clear line of sight to the region, where the user's hands would be placed when using the hand dryer 1. In various modifications, the number of sensors 17 can be v aried. In the variant in Figure 3 there are three sensors 17, while in the variant of Figure 9C there are two sensors, although the number of sensors may be modified.

Spray Pump Variant 2

In Figure 10, a second exemplary variant of a pumping mechanism makes use of an eccentric drive to perform the act of intermittently pressing against a modified nosde cap 755 A to activate a burst of spray.

Figures 11 A and 1 IB show the eccentric drive 760 that moves a rocking arm 763 that intermittently presses on. the nozzle cap 755A to emit a spray.

The sequence of diagrams in Figures 12 A to 12D illustrate the movement of the rocking arm 763 that enables the arm to intermittently press against the nozzle cap 755.A.

In the embodiment of Figures 1 1 A and 3 IB, the nozzle cap 755A is provided w'ith a spray-outlet in the form of an atomizer spra duct 758A. When the rocking arm 763 presses on the nozzle cap 755A, a small burst of liquid is emitted from the spray duct 758A. The liquid is drawn from an internal reservoir container that resides inside the reservoir shell 7 of the modified pump spray apparatus 700B.

As the rocking arm 763 presses on and lifts off the nozzle cap 755A, the spray duct 758 reciprocates back and forth. Hence, in the embodiment of Figure 14 A, the exit-facia plate 15, of that particular modification, is provided with an elongated apenure 759A to reveal the spray duct 758.A, The aperture 759A is elongated so as to reveal, the spray duct: 758A throughout the range of its reciprocal motion.

Consequently, in the modification in Figure 12E, the nozzle cap 755 A is provided with a semi-cylindrical shield 755 B. The shield 755.B fits across whatever portion of the elongated aperture 759A. that is no taken up by the spray duct 758.4. The shield 755B seals the aperture 759A to prevent ambient air entering from the aperture 759A into the inner chamber 13, The seal, created by the shield.755B and. the elongated aperture 7S9A„ may be enhanced by a resilient gasket material, or other suitable methods of enhancing seals to prevent ingress of air.

In Figure 12 A to 12E, and Figure 13A and 13B, the eccentric drive 760 is formed around an axial shaft 761 of a spray-pump motor 762. The eccentricity of the drive 760 imparts a rocking motion to the pivotal rocking arm 763 that has a lower end 764. The lower end 764 is adapted to press against the nozzle cap 755A.

Figure 11 A shows an. arrangement where the nozzle cap 755 A is not depressed by the end 764 of the rocking arm 763.

Figure 1 IB shows the same arrangement with the nozzle cap 755A is depressed by the end 764 of the rocking ami 763 that causes liquid to be sprayed through the atomizer spray duct 758A.

In use, when a user places his hands underneath the hand dryer 1 to dry his wet hands, the sensor or sensors 17 detect the presence of the hands. An electrical control circuit instigates the pump spray apparatus 700B to emi t one or more bursts of sprayed liquid.

In the embodiment, electrical control circuit includes a spray-s top-start system

comprising- a combination of components, as described below:

In the rotational sequence in Figures 12A to 12D, the shaft 761 rotates around its axis. The circular cross-section of the eccentric drive 760 is not concentric with the axis of the shaft 761. Rather, the circular cross-section is biased towards one lateral, side of the axial shaft 761. Therefore, as the shaft 7 1 rotates axially, the biased portion of the body of the eccentric drive 760 mo ves around the axis of the shaft 7 1 ,

(For illustration sake only, in Figure 12A the body of the eccentric drive 760 generally points around 3 o'clock; in Figure 1.2B the eccentric drive 760 generally points around 6 o'clock; in Figure 12C the eccentric drive 760 generally points around 9 o'clock; in Figure 12D the eccentric drive 760 generally points around 1 1 o'clock; which brings the eccentric drive 760 back to its starting position generally around 3 o'clock in Figure 1 A.)

In order to communicate to the spray-stop-start sy stem that a burst of spray has been emi tted, the shaft 761 is provided with a laterally projecting tab 765. The end of the tab carries a small magnet, and this magnet rotates in a circular path as the tab 765 rotates with the axial shaft 76 L In the embodiment, the magnet is a rare earth magnet.

In Figures 11 B and 12B, a Hall-sensor 766 is positioned in front of a window 767 that is positioned on a portion of the circular path of the magnet. The Hall-sensor 766 is part of an electrical circui t on a printed circuit board 768 of the electrical control circuit that is housed in the body of an internal component of the apparatus.

The Hall-sensor 766 is able to detect the magnetic field from the magnet on the tab 765, each time the tab rotates past the window. In Figure 12C, the arrangement is such that the tab 765 passes the Hall-sensor 766 at or proximate the point when the rocking arm 763 presses on the nozzle cap 755A to emit the spray, Thus, each passing of the tab 765 o ver tire Hall-sensor communicates to the control mechanism of the electrical circuit that a single burst of spray has been emitted.

Each 360 degree rotation of the eccentric drive 760 equates to one rocking motion of the lower end 764 of the rocking arm 763, which equates to one press of the pump, which equates to a single spray emitted from the spray duct 753A,

Thus, each single full rotation of the shaft 761 corresponds to one pump action that emits one burst of spray. Hence, the rotation of the tab 765 tells the control mechanism that one pump action has been effected, and thus the motor can stop gradually rotating.

Thus, Figure 12A shows the rocking arm 764 in its rest position. When a user places his hands beneath the hand dryer 1, (he spray-stop-Start system instructs the spray-pump motor 762 to start rotating, and it does so according to the rotational sequence of Figures L2B to 12D. When the tab 765 rotates past the Hall-sensor 766, the spray-stop-start system instructs the spray-pump motor 762 to gradually stop rotating such that it comes to back to its rest position shown in Figure 12 A. In the embodiment, this is achieved by the electrical control circuit: gradually decreasing the electrical current to the spray-pump motor 762 such that decelerates to a halt in its resting position of Figure 12 A.

In the embodiment of Figure 3 , each time the user places his hands under the hand dryer L ei ther one or preferably two bursts of spray are emitted. In other embodiments, any number of bursts may be emitted as is considered desirable under the prevailing conditions.

In. the embodiment, electrical control circuit instructs the spray-stop-start: system instigates the emission of two bursts of spray, and the timing is such that a period of a few- seconds elapses between the two bursts, for instance, five seconds in between each burst of spray.

The spray can be activated at various times, depending on the intended outcome for the spray for each embodiment and modification. For example, in one scenario example, the spray may be required merely to be sprayed into the airflow to cover a user^'s hands with the liquid anti- germ substance. In such a scenario, the embodiment can includes the sensors 17 which identify when a user's hands are placed beneath. The embodiment includes an electronic circuit that connects the sensors 17 to the activation mechanisms of the pump spray apparatus 700A, so that the pumping mechanism is activated periodically durin the timeframe that the sensors 1 detect that the user's hands remain under the hand dryer while the user is drying his or her hands.

In another scenario example, the apparatus 1 is embodied merely as an air purifier, for instance, that is designed to purify the ambient ai in a living room or a public area. In such a scenario, the embodiment can includes an electronic timing circuit that periodically and

simultaneously activates, firstly, the fan-motor 405 that drives the fan inside the Ian-casing 400 and, secondly, also activates the pump spray apparatus 700A to add the liquid substance into the outgoin -airflow 200C. In various such embodiments, the sprayed liquid substance may be an anti-germ substance or a fragrance substance,

In a preferred further embodiment of Figure 12E, the spray duct 758 A is preferably positioned at the distal end of a protrusion 754. In the embodiment, the length of the protrusion 754 allows the spray duct 758A. to be positioned slightly away from interna regions of the hand dryer I . Within the internal regions of the hand dryer 1 , air is sucked into the fan-casing 400, and tliis movement of air towards {he fan in the fan-easing 400 is experienced, to varying degrees, throughout the internal regions of the hand dryer ! that are in communication with the inner chamber 13. Therefore, the preferred protrusion 754 is able to position the spra duet 758A slightly away from the main inner regions of the hand dryer I . E ven though, in the further embodiment the protrusion 743 is only about 2 mm, it is found that such a small extra distance aids to minimise the likelihood of sprayed substance being substantially sucked back inside the hand dryer I .

in other embodiments, the position of the printed circuit board 768 may be re-arranged in other locations inside the inner chamber 13. In other embodiments, preferably the printed circuit board 768 is located in a position inside the chamber 13 where it is not directly underneath a potential source of liquid, such as directly beneath the replaceable bottles 61 . or the internal reservoir container that resides inside the reservoir shell 701. in normal usage, it is not anticipated that there would be any leakage from such sources of liquid, however, as a precaution again unintended failure of such liquid containers or liquid sources, the printed circuit board 768 is preferabl located away from directly under these liquid sources, should any leakage occur, so as to avoid damage to the electrical circuitry. Spray Piu p Variant 3

In Figure 14B, a third exemplary variant of a pumping mechanism is a modification which is provided with a stationary spray duct. 758C that slightly protrudes from the undersur face of the exit-facia plate 15, The stationary spray duet 758C is arranged to spra its liquid into the outgoing airflow 200C.

Figure 14C shows cut-away portions of the variant of Figure 14B. A rocking arm 763 rocks backwards and forwards in a manner described for the earlier embodiment. The lower end 764 of the rocking arm 763 intermittently presses on a head of a plunger assembly 75SC. Such depression of the plunger assembly 755C causes a burst of liquid to be emitted from the stationary spray duel 758C. The liquid is drawn from an internal reservoir container that resides inside the reservoir shell 701 into the plunger assembly 755C. A thin tube 757 connects the plunger assembly 755C to the stationary spray duct 758C. Pjacement.of Ant|-Gm

Preferably, any anti-germ substance used in: the first layer 418 of the three-dimensional, filter 410, or in the filter interior 41 i of the three-dimensional filter 410, for example the tablets 421, is able to be substantially toxic to humans. This is because any such toxic materials are entrapped by the second layer 41.9 of the filter 410,

In contrast, preferably, an anti-germ substance used elsewhere in the filter interior 411, the airflow path and outside of the three-dimensional filter 410, is substantially non-toxic to humans. For example, any anti-germ materia! effused oil^" the air wick 600 would be substantially non-toxic. Also, any anti-germ liquid sprayed by the pump spraying apparatus 700A onto a user's hands would consist of substantially non-toxic material. There reference to "substantially nontoxic" means that the materials are regarded as non-toxic when used according to prescribed guidelines, since such non-toxic substances may become toxic when used outside of guidelines for that particular material, Exit of Airflow

In partial Figure 4, and in partial Figure 5, after the airflow 200A emerges from the top and lateral sides of the three-dimensional filter 410, the airflow 200B moves within the inner chamber 13 until the airflow is sucked and drawn into the fan-casing 400.

in Figure 7, after the airflow is drawn into the fan-casing 400, the airflow 200C travels through the elongated, tapered passageway 16 until the air is exits the hand dryer 1 through the exit-aperture 14 which is located at the end of art elongated, tapered passageway 16.

The tapered passageway 1 is shown in partial. Figure 4 and Figure 7, and partially obstructed from view in Figure 5. The exist-aperture 14 is located in an e it-facia plate 15. The exit-facia plate 15 is snap-fastened to the hood 10 by resilient claws 18.

Note that Figure 4 is, in a sense, a cut-away or partial drawing because, in Figure 4, parts of the embodiment have been omitted from the drawing merely in order to show the tapered passageway 1 , whereas Figure 5 provides a normal view in which the tapered passageway 16 is partly obstructed from view by the components. Air Freshener

In other embodiments, the air purifying apparatus may be embodied, instead of a hand dryer 1 , but rather as an air purifier or air freshener

in an embodiment of an air purifying apparatus, which is in the form an air purifier or air freshener, the apparatus and its components are substantially represented by the example given in the hand dryer I, with the following preferred modifications:

1) An induction motor is used since the activity of an air purifier or air freshener can require the apparatus to purify airflow for considerably longer time periods than m embodiment in the form of a hand dryer. An induction motor is more suited to this manner of operation than a universal motor. For instance, where a hand dryer might operate for less than a minute while the user dries his hands, an embodiment in the form of an air purifier or air freshener may operate, for instance, for an hour or so or longer, to continuously purify the ambient atmosphere of the human-activity environment,

2) The motion sensor 17 may be arranged to detect motion in the wider vicinit around the apparatus, fo instance, a person entering the room in which the air purifier or air freshener is installed,, as compared to a hand dryer 1 where its motion sensor system is intended to detect the presence of a user's hands directly under the hand, dryer.

Alteration of Airflow Pat Size

In operation of the hand dryer 1 , the fan, which is housed in the fan-casing 400, generates an internal airflow 200B that is instrumental in transferring the anti-bacteria substances from v arious components of embodiments of the germ-killing system; such as the germ-killing filter 18 of the three-dimensional filter 1 OA, the anti-bacteria tablets 421 A, 42 IB, 421 C, and the air wick 600.

Without being limited by theory, in the exemplary embodiments, it is found that the speed or rate of airflow over or through these components can influence the efficiency with which the anti-bacteria substances are transferred from the components into the airflow. Moreover, each type of component, from which the anti-bacteria substances emanate, may have an optimum airflow that differs .fo each components. Also, the rate of airflow throughput, and the speed of the airflow over each of the componen ts, arc influenced by a number of parameters, including such as: the power of the fan-motor, the shape of the spaces through which the airflow passes, the total volumetric size of the inner chamber 13, to name a few such parameters. Another relevant factor may be the level of noise which is generated by the fan-motor for any given rate of airflow throughput, wi th a tendency of higher noise levels being associated with faster motor speed.

Hence, in each exemplary embodiments and in further modifications, there may be required some degree of experimentation to identiiy an achievable rate of airflow that is judged to be an optimum, having regard for the performance of each of th anti-bacteria-emitting components operating with that one rate of airflow throughput through the apparatus, as wet! as regard for the noise-level of the fan-motor.

Therefore, the embodiment may be provided with an airflow-path-size-alterable arrangement which enables adjustment of (he size of the path through which (he airflow passes.

The embodiment of Figure 4 and Fi g ure 5, and the embodiment in Figu res 1 A-C, is provided with airflow-path-size-alterable arrangement that enables adjustment of the size of at least part of the airflow path within the dryer 1.

in the embodiment, the asrflow-path-size-alterabie arrangement is in a form that includes a gap-adjustment plate 404 that enables adjustment of the size of the gap 407A. Adjustment of the size of the gap 407A either increases or decreases the size of the p&th through which airflow passes to reach the fan.

The fan-motor 405 and motor-housing 403 are supported on the gap-adjustment plate

404.

The plate 404 has one or more apertures through which parts of the fan-motor 405 connect to the fan that is inside the fan-easing 400. For example, the fan-motor 405 has a rotating shaft tha imparts rotation to the fan. The shaft passes through an aperture in (he gap-adjustment plate 404. Part of the airflow passes through the holes 402 of the motor-housing, and then through the aperture or apertures in the plate 404, en route to the fan in the fan-casing 400.

The gap-adjustment plate 404 is attached to the fan-casing 400 by a number of supporting posts 406. In the embodiment, there are four such posts 406, but the number can vary in other modifications, for example, there may be three or four posts or other forms of support.

n {he embodied examples of Figure 4, 5, 7, 15 A, 15B, the airfiow-path-size- alterable arrangement may be in the form of, or may include, an arrangement: that facilitates adjustment of the gap-adjustment plate 404, The embodiment is not restricted to one particular mechanism for enabling adjustment of the size of the gap 407A. In the embodiment of Figure 5, and the embodiment in Figures 15.4, 15B and 15C, adjustment of the gap 407A may be achieved by the selection of varying thickness of ring-like gaskets 408. The ends of the posts 406, have narrowed ends which receive the ring-like gaskets 408. The gap-adjustment plate 404 is provided holes thai each correspond with the location of one of the posts 406. The gap-adjustment plate 404 is seated on the set of posts 406, with the gaskets 408 sandwiched in between. Selection of thicker gaskets causes the gap 407A to be wider, while selection of thinner gaskets causes the gap 407A to be thinner.

in the embodiment, the gaskets 408 are preferably made of a resilient material such as natural rubber, artificial rubber, or a resilient polymer suitable for use as a resilient gasket. The resilient gaskets are able to at least partially absorb vibrations from the fan-motor 405.

In the embodiment, the gap 407 A is about 10 mm, and in the example it is found that adjustments in the gap size in the order of around 10 to 20 mm, for example, may result in a .noticeable change in the rate of airflow inside the inner chamber 13. This example of a 10 mm gap size, however, is not prescriptive for every other embodiment because experimentation is required in each configuration.

In a further example, in the modification of Figures 15 A, 15B and 15C, the airflow-path- size-alterable arrangement may also include, or may be in the form of a modified filte holder 11 A that is provided with slits 407.B which act as pathways for the airflow to pass through en route to the fan that is inside the fan-casing 400. In the arrangement, the airflow' -path-size is alterable by interchanging the filter holder 611A with a replacement holder that has a different sized flow path. The difference in flow path size can be achieved by modifying the replacement holder to have larger slits and/or an increased number of slits.

In the embodiment of Figures 15A, 15B and 15C, airflow passes through the two slits

407B en route to the fan in the fan-casing 400.

As the airflow passes through the slits 4 7B into the fan-casing, that airflow passes across the inner face of the filter 613 tha is carried by the modified filter holder 61 1 A.

Thus, at the filter holder 611 A, part of the airflow passes directly through the filter 613, and another part of the airflow enters through the side slits 407B to pass across the rear face of the filter 13. Without being limited by theory, it is believed that movement of airflow, across the inner or rear face of the filter 6 S 3, partially contributes to the drawing of airflow through the front of the filter. (In Figures 15 A, ,15.B and 15C, the inner or rear iace of the filter is that portion that is closer to the fan-casing).

The one or more side slits 407B are adapted to allow, in use, a portion of the airflow to enter the filter holder through the one or more side slits 407.B so as to pass across a rear face of the filter 6 i 3 while, in use. another portion of the airflow enters through the filter 61 3, such that the passage of airflow through the one or more side slits 407B serves to draw the airflo through the filter 613. in the embodiment, of Figures 1 A . 15 B and 15C, preferably there are two side slits

407B.

in other modifications, preferably there are two slits 407.B, but the number of slits 407B in the modified filter holder 61 ! A may vary from having one slit to having several slits.

'Preferably, as shown. In Figures 15 A, 15B and 15C. the two side slits 407B are provided only on one hemispherical half of the modified filter holder 61 1A, and not around the entire circutnferen.ee or rim. Without being limited by theory, it is believed that having slits only on one side contributes to a smoother airflow behind the inner face of the filter, thus avoiding a tendency for greater turbulence if the airflow were to enter through slits at opposing sides, for example.

In referring to the provision of slits 407 B only on one hemispherical side, it is understood that, in use, the one hemispherical side may be positioned at any location on the rim of the filter holder. In Figures 15 A, 15 B and 15C, the slits are positioned on a lateral side of the filter holder, but in other modifications the slits may be positioned at a lateral top or bottom of the filter holder.

In the embodiment, the combined, flow paths, firstly provided, by the gap 407A between the plate 404 and the fan-casing 400, and secondl provided by the slits 407^'B in the modified filter holder 61.1 A, can be adjusted to achieve a desired rate of airflow through the dryer 1 ,

The inner chamber is a scaled enclosure, with the inlet aperture 101 being the only air inlet aperture and the exit- aperture 14 being the only air exit. Therefore, preferably, the rate of airflow through the dryer 1 is set such that the amount of airflow 200 A entering the apparatus is roughly equivalent to the am ount of airflow 200C exiting the apparatus, in order to avoid fl ctuations in pressure in the inner chamber 13 of the hand dryer 1 .

Watser-less Hand Washing Figure |6A shows yet another embodiment of an air purifying apparatus in the form of a hand cleaner-dryer 1 A. The hand cleaner-dryer is adapted to be used in a method of water-less washing of hands, however, there are some spheres of activity where washing of hands with water brings with it a set of disadvantages.

Bacteria and germs breed and live in water. Without being limited by theory, il is believed thai, when users wash their hands with water and do not properly dry their hands, a result is that the bacteria can be carried particularly in the moisture that remains on the hands. Even the drying of hands with paper towels can leave amounts of moisture on hands that can encourage bacteria growth on the hands. Normally, a user washes his hands with water, and then may use a hand drying apparatus to dry the hands in the stream of air.

in contrast, in the embodiment of Figure 16 A, a method of waterless washing of hands involves dousing the user's unwashed hands with a large quantity of anti-germ liquid, and using a high-speed steam of substantially germ-free air to dry the hands rapidly.

The- hand cleaner-dryer 1 A has a baseplate 1 1 A that is able to be mounted on a wall during installation.

The embodiment of Figure 16A is provided with two sets of components of an airflow- germ-kil ling-system both working in parallel in order to deliver the large quantities of anti-germ liquid and germ-free airflow onto the hands when implementing a system of water-less washing of hands.

Large quantities of anti-germ liquid are stored in two large internal reservoir containers

701 A.

in use, airflow 2 0.A enters the hand cleaner-dryer 1 through an inlet m the form of two inlet ape tures 101 A, and each stream of airflow immediately enters one o the larger three- dimensional filter 410B, described above in relation to Figure 6F.

In an analogous manner to the operation of the embodiment shown in Figure 1, 4 and 5, the present embodiment of Figure 16B operating on the basis of the airflow being purified by passing through the larger three-dimensional filter 41 GB, and then entering into the inner chamber 13 A of the hand cleaner-dryer 1 A, and then bring drawn into a pair of fan-casings 4Θ0Α, and the being expelled as an airflow 200C of substantially germ-free air from the cleaner-dryer 1 A through a pair of tapered passageway 17A. The outgoing airflow 200C is directed onto the user's hands.

in the example embodiment of Figure 16A. the hand cleaner-dryer 1 A is provided with modified embodiments of an airilow-gemi-killmg-system which have been described by way examples with reference to the earlier embodiment of Figaro 1.

For example, in the embodiment of Figure 16A, the intakes to the fan-casings 400A may be provided with a wick-delivery-sysiem such as in the examples described with reference to Figures 8 A and fiB.

Rotary_Sp_ray

In the embodiment of Figure 16 A, the hand cleaner-dryer I A is provided with germ- kiliing-substanee-effuser in a form that has a spray-outlet. The spray-outlet is in a form of an arrangement of several atomizef spray ducts 758B. In Figure 16A, five spray dacis 758B are arranged on a duct-support 749. Each of the spray duets 758 are shaped to spray liquid in a roughly cone-shaped trajectory. On the duct-support 749, each of the spray ducts 758 is arranged to spray liquid in a different direction in order to allow the liquid to hit the user's hands in a range of varied directions.

in a modified embodiment, the duct-support 749 may be rotated as spray is emitted from its spray ducts 758. in other modifications, the direction of rotation of the duct-support 749 may be intermittently and periodically changed, for example, from clockwise to anti-clockwise.

In Figure 16B, the several atomizer spray ducts 758B receive anti-germ fluid from the two large reservoirs via thin tubes 757A (which are not shown, for the sake of clarity, in the exploded view of Figure 16C or the partial view of Figure 16D),

For the embodiment of Figure 16A, in use, when a user places unwashed hands underneath the hand cleaner-dryer 1 A, a large quantity of anti-germ liquid is expelled on the user's hands via the several atomizer spray ducts 758B. The outgoing airflow 200C of substantially germ- free air is used to dry the user's hands, in such a manner, the user's hands are able to be washed and dried without the use of water.

In Figure 16D, each of the inlet apertures 101 A, J01AA has a plane B-Bl , B-B2 that defines the front face of its opening. For each of the apertures 101 A, 101 A A their respective planes B-B l , B-B2 are perpendicular to the central axi s A- A, such that the l ce of each inlet apertures points directly downwards in the direction of the central axis A-A. In other words, in Figure 16D, the lane B-Bl of one of the inlet apertures is co-planar with the plane B-B2 of the other of the inlet apertures.

Dual Direction Inlet Apertares

Figure 17A shows another embodiment of an air purifyin apparatus in the form of another hand dryer IB.

In {he embodiment of Figure 17 A, the incoming stream 200 AA of the airflow is sucked into the hand dryer I B through an inlet.

In Figure 17A, the inlet is in the form of two inlet apertures 101 A, 101AA, The two inlet apertures 101 A, 101 A A each draw in part of any incoming airflow 200AA in a lateral direction relative to a central axis A A of the housing of the hand dryer IB.

Each of the inlet apertures 101. A, iOlAA draws in part of an incoming airflow 20 A A from a different direction relati ve to ther of the inlet apertures. Thus, in Figure 17A, one 101. A of the inlet apertures draws in airflow from the left side of the ax-is A-A, while the other 101AA of (he inlet apertures draws in airflow from the right side of the axis A-A.

The two inlet apertures 101 A draw in the incoming airflow laterally from the right hand side and left hand side of the central axis of the housing when mounted on a wall.

in this embodiment, the inlet apertures 101 A are arranged so as to receive air from either side of the hand dryer IB when mounted on a wall, in contrast to the embodiment of Figure 1 which is arranged to receive air generally from directly beneath the apparatus.

Each of the inlet apertures 101 A, 101 A has a plane B-Bl , B-B2 that defines the front face of its opening. For each of the apertures 101 A, lOiAA their respective planes B-B l, B-B2 are not perpendicular to the central axis A- A, in order thai the face of each inlet aperture points, to a degree, away from the central axis, and not directly downwards in the direction of the central axis A-A. In other words, in Figure 1 7 A, the plane B-Bl of one of the inlet apertures is not co- planar with the plane B-B2 of die other of the inlet apertures. This is in order to maximise the area from which air can be actively drawn into the apparatus from the ambient urnan-activity- envirotiment.

In further modifications, the number inlet apertures may be increased beyond two apertures. For instance, a modified unit may have four inlet apertures, with the faces of the inlet apertures all pointing in a variety of directions to maximise the area from which air can be actively drawn into the apparatus from the ambient human-activity-environment.

In. other embodiments the angle o the plane B-B can be varied from just a few degrees from being perpendicular to the axis A-A, all the way to the plane. B-B being parallel to the axis A-A.

An advantage of having an inlet, i the form of multiple inlet apertures which point in different directions relative to the axis A-A, is that the inlet apertures are thus able to draw in contaminated air from a wider region of the ambient h uman activity environment: so as to be more efficient at purifying the ambient atmosphere of germs.

Arc^a _.!^™eni _.Of jn|ei& _.Oujlej

Prior art Figures 1 A and 1. B are schematic diagrams of end views a prior art hand dryer or air purifier viewed from beneath when, the apparatus is mounted on a wall 3 or other upright surface. In each case, in the known hand dryers 805A, 805B in Figures 1. A and 1 B, when the apparatus is installed on the wall for use, the arrangement of the apparatus is such that the inlet 801 A is in between the wall 3 and the outlet 81.4, Without being limited to theory, it has been found that such an arrangement, resulting from the design of the known hand dryers 805 A, 80SB, tends to result in a significant build-Hp of dirt and grime on the exterior parts of the hand dryers 805A, 805B.

In contrast, in embodiments of the present invention in Figures 3, 16 A and 17.B, when the hand dryers and other air purifiers i , i A, 1 B are mounted on a wall 3 or other upright surface, the arrangement of each of the apparatus is such that the respective inlet apertures 101., 101 A, 1 1AA are not in between the wall 3 and the outlet 14 or whatever form of outlet each embodiment provides.

Rather, in Figures 3, 16 A and I 7B, in each embodiment, the inlet is alongside the outlet. In the embodiments of Figures 1, I 6A and 17B, each apparatus has a baseplate 1 1, 1 1 A.

In each embodiment, the respective inlet apertures 101, 101 A, 101 AA are not in between the baseplate and the outlet 14 or whatever form of outlet each embodiment provides.

In Figures 1 , 2 and 3, the inlet 101 is not between the outlet .14 and the baseplate 11. Both the inlet and the outlet are on the underside of the apparatus.

n Figure 16A, the two inlets lO! A are not between, the outlets 14A and the baseplate

11 A.

In Figure 16B„ the two inlets 101 A, 101AA are not between the Outlets 14B and the baseplate of the embodiment of Figure 16B.

Another way of describing the arrangements in Figures 3, 16A and 17B is that each inlet and outlet is arranged on the underside generally in a row or sequence where the direction of the row or sequence is generally alongside the base-mounting.

For example, in Figure 3, the general direction of the row or sequence is shown as dotted line R-R. This direction R-R is generally alongside the baseplate 1 1 that is also alongside the wall .3.

For example, in Figure 17B, the general direction of the row or sequence is also shown as another dotted line R-R. This direction R-R is generall alongside the baseplate 11 that is also alongside the wall 3.

Substantial Si e of Inlet

By way of background, the airflow 200C that exits each air purifier 1, 1 A, I B has been purified, and so the exiting airflow 200C will not contribute substantially or at all to build-up of dirt on the underside of the dryer 1 , 1A, IB. ndeed, in use, the strength of the outgoing airflow 2O0C deters un-purified air of the incoming airflow 200A from contacting a region of the underside that is proximate the outlet apertures 14B. in this specification, this general region thai is, in effect, largely shielded from any incoming airflow 200A by the force and flow of the outgoing airflow 200C, is referred to by definition as an outgoing-airflow-protected-surface- region.

In the example of Figure 3, the approximate region of the outgoing-airfiow-protected- surfaee-region is regarded as being the entire half of the underside of the hood 10 indicated by the arrow I OA and clotted line S-S.

In another example of Figure 17B, the approximate region of the outgoing-airflow- proteeted-surface-region is regarded as being around the central portion of the underside of the hood 10 indicated by the arrow 10A and the doited lines S-S,

Build-up of dirt and grime occurs as the un-purified incoming airflow 200A passes across surface area of the hood 10 and its underside, over a period of time, resulting in a build-up of dirt on these surfaces that are in regular contact with the un-purified incoming airflow 200A.

In this regard, in the exemplary embodiments in Figures 3, 16A and 17.B, on the surface where the outlet and inlet are positioned, it is preferable that the inlet aperture or apertures 1 1, 101 A occupy a very substantial portion of the surface that is outside the outgoing-airflow- protected-siirface-region. The effect is to minimise the amount of exposure to the incoming airflow 2 0A experienced by the underside surface that is outside the outgoing-airflo -protected- surfaee-region . in other w ords, it is a minimisation of the amount of surface area on w hich dirt can accumulate.

Germ- iliug-h in a modified embodiment, a variant of the germ-kiiling-substance-effuser of the dryer is provided with, and is thus able to spray, a germ-kiiling-liqiiid-substanee. The germ-killing-Hqiiid- substanec is sprayed into the outgoing airflow 200C in order for fee genn-killing-liquid-substance to reach and sufficiently coat the user's hands.

In the modification, the germ-killing-liquid-subsiance preferably contains 3 disperser, in fee modification, the disperser plays a role in enhancing the dispersal of at least one or more antimicrobial agents on the skin of the user's hands.

Without being limited by theory, it is believed that the disperser acts as a carrier for at least one or more germ -killing components of the germ-killing-liquid-substanee. As the disperser is carried b the airflow 200C onto and dispersed over the user's hands, the disperser effectively aids in the dispersal of one or more germ-killing components over the skin of the user 's hands. Preferably, the disperser comprises one or more surfactants, optionally including one or more super surfactants. The disperser may include an alkyl glucoskle. Preferably, the disperser includes one or more glycosides, such as Decyl Giucoside and/or Oety l Glucoside.

The mixture further includes at least one antimicrobial or biocide substance. The biocide may include one or more quaternary ammonium compounds. Preferably, the mixture includes a first biocide s ubstance in the rm of a quaternary ammoni salt of the formula:

Ar is an optionally substituted aryl or heteroaryl group. Preferably, Ar is selected from optionally substituted phenyl, benzyl, naplithyl. and pyrtdyl groups. Most preferably, Ar is an optionally substituted aryl group. Most preferably, Ar is an optionally substituted benzyl group.

R is any 06 or above unsubstiiiited branched or linear alkyl group. Preferably, R is any C8 ox above unsubstituied branched or linear alkyl group. More preferably, ii is any C 12 to C20 tmsubstituted branched or linear alkyl group. Most preferably, it is any C12 to C20 unsiihstituted linear alkyl group. Particularly preferred R is an imbranched unsubstituted C18 alky] group.

Each group Rl is independently selected from an CI to C4 branched or unhraached

unsubsti luted alkyl. Preferably Rl are each independently selected from methyl, ethyl, propyl, butyl and isopropyl. More preferably, R 1 are each methyl groups. is a halide anion. Preferably X is fluoride, chloride, bromide or iodide anion. Most preferably, X is a chloride ion.

Still more m salt of the formula:

wherein R l is C8, C 10, C 12, C 14, CI 6, CI 8 alkyl, preferably CI 2 or C14 alkyl; R2 is H or C1.-C5 alkyi, preferably H; and

X is Br, CI or F, preferably CI.

Most preferably, the first biocide substance is an Alkyi Dimethyl Benzyl Ammonium Chloride (Benzalkonium chloride, B AC).

The mixture preferably further comprises a second biocide substance. The second biocide substance may he a cationic biocidally active surfactant. The second biocide substance is optionally taken from the group including alkyi dimethyl benzyl ammonium (C8-C18), dialkyl dimethyl ammonium (C8-C12) and didecyi methyl polyethoxy ethyl ammonium and himethyl ammonium. Most pre ferably, the second biocidai substance is in the form of Didecyi Dimethyl Ammonium Chloride (DDQ) having the formula;

The ratio of the first biocide substance and the second biocide subs tance may be between 1 :2 and 2: 1 , more preferably l:.l , and most preferably is 4:6.

Advantageously, the germ-killing-liquid-substanee, including the disperser, includes a precise mix ture of 3 active biocide substances.

Accordingly, in a preferred form of the invention, the mixture includes a first biocide substance in the form of Alkyi Dimethyl Benzyl Ammonium Chloride (BAC), and a second biocide substance in the form of Didecyi Dimethyl Ammonium Chloride (DDQ).

Preferably, the ratio of the .first biocide substance and the second biocide substance may be between 1 :2 and 2: 1, more preferably 1 : 1 , and most preferably is about 4:6..

Preferably> the third biocide substance is a biguaiiidc.

The third biocide substance may comprise a substance of the formula:

here n is 1 or 2.

The third biocide substance more preferably comprises a guanide having the formula;

where n is the number of monomers consistent with stabilised micelles in the range of 1 - 100 nm, preferabl 5 - 10 mm.

Preferably the third biocide substance is therefore poly-hexamethyJene biguanide. The ratio of the third biocide to the combination of the first two biocidal substances may be between 1 :2 and 2:1 , more preferably between 2:3 and 3:2 and most preferably is about 1 : 1.

The disperser may also include at least one inactive ingredient. The inactive ingredient may be a. surfactants. The surfactant is preferably an alkyl ghicoside. Still more preferably, the inactive ingredient includes one or more of Decy IGlucoside and GctylGiucoside. This or these inactive ingredients are preferably effective to stabilize the mixture. Preferably, the ratio of .DecylGhicoside to OctylGlucoside is between 1 :2 and 2: 1, more preferably between 7:5 and 5:7, and most preferably about 6:5.

The inactive ingredients, for example DecylGhicoside (DO) and OctylGlucoside (OG), are effective to stabilize the mixture of the one, two or three biocide substances. Applicants believe that the inactive ingredients, such as DG and OG, act as the carrier and disperser to spread the biocide substances mixture effectively.

The inventive formulation preferably results in stablised micelles in the 5-1.0 nanometer (nm) range. This allows the geon-kUling-Uquid-substance (such as the exemplary mixture of 3 biocide substances) to achieve a higher germ-killing efficiency at lower concentrations, than would an unstabiiised mixture of the one or more bioci de substances.

Accordingly, with respect to the preferred genn-killing-Hquid-substance, the combined mixture of^" the first biocide substance, the second biocide substance, and the disperser, all three acting together, mean that lesser quantities of the first and second biocide substances are required to achieve the same kill-rate of germs on. the user's hands, compared to a case if the disperser is no present.

More particularly, the combined mixture of the three active biocide substances, and the disperser, the one or more components interacting and or acting together, mean that lesser quantities of the included biocide substances are required to achieve the same kill-rate of germs on the user's hands, compared to a ease where the disperser was not present.

in another embodiment, the germ-killing-liquid-substaace s a compositio comprising: i) an aikyl silyl ammonium film-forming conipouad;

ii) a benzalkonium or benzethonium chloride;

v) a polymeric biguanide; and

vi) a disperser or surfactant system comprising:

a. an alcohol ethoxyiate; and

b. an alkyigiucoside or alkylpolyglycosidc.

This embodiment is suitable to be carried in an aqueous carrier.

In some embodiments, the aikyl silyl ammonium film-Jormmg agent is a conipouad of formula ):

[R_i)₃Si-A-Nⁱ(W)(X)(Y)j M.^" (I)

wherein each R: is independently selected ^'from ^'hydrogen and -Cj-saikyl;

A is a Ci._f.alkylene group;

W and X are independently selected from -Ci.₍-,alkyl;

Y is a C(o_2tialk ^'l eroup; and

M is an anionic countcrion.

In particular embodiments, one o more of the following applies in relation to formula (I): Ri is hydrogen, methy l or ethyl, especially methyl or ethyl, more especially methyl;

A is a C_2- a1kylene group, especially -CH₂CHjCHr;

W and X are independently selected from methyl and ethyl, especially methyl;

Y is C;o-ii>alkyl; especially Cioalkyl or C_!Salkyl, more especially C_1¾aikyi; and

M is selected from F^", CI^", Br^" and 1^", especially CI^'.

In particular embodiments, the aikyl silyl ammonium film-forming compound of formula

(I) is selected from ί -octadeeanammium- , -dimeihyl- -[ 3 rimethoxysily1(propyl) |ehloride

(also known, as 3-irimethoxysilyipropyl-N_;N-di!nethyl-N-octadecyl ammonium chloride), 3- triethoxysiiylpropyi- , -dtniethyl-N-octadecyi ammonium chloride, 3-triethoxysilylpropyl-N,N- dsmethyl-N-isodecyl ammonium chloride and 3-trmieraoxysilylpfopyi-N,N-dimcthyl-N-isodecyl ammonium chloride.

The aikyl silyl ammonium film-fonning compound is present in the composition in an amount in the range of 0, 1 % to 1.5% w/w, especially about 0.3% to 1.0 % /w, more especially about 0.4 to 0.6 % /w of the composition.

In some embodiments, the benzalkonium or benzethionium chloride compound is a compound of formula (II):

wherein ¾ and R₃ are independently selected from C alkyl and

R is C _Salkyl or Η ¾("ΗαΟ)₂ 4-( 1 -diraethyi-3-dime{hylbaiyl)phenyl|.

In particular embodiments, one or more of the following applies:

R₂ and R₃ are independently selected from methyl or ethyl especially methyl; and

R.₄ is selected from C_$, CH>, CU, 14, C_J(! or C_{i S} alkyi. or mixtures thereof or -(CH₂CH₂0)₂ 4-( 1- dimeUiyJ -3 -dim eth l btrtyi)phenyi] .

The ben/alkonium or benzthionium chloride compound is present i an amount in the range of about 0.1% to 1.0% w/ of the composition, especiall about 0.1% to about 0.5% w/w, more especially about 0.1% to 0.2 % w/w of the composition.

in some embodiments, the polymeric biguanide is a compound of formula (III):

wherein Z is absent or an organic divalent bridgin group and each Z may be the same or different throughout the polymer; n is at least 3, preferably 5 to 20 and X^' and X⁴ are independently selected from -Nf¾, - H-C(= :1)-Nli-CN, optionally substituted alkyl optionally substituted cyeloaikyi, optionally substituted aryi, optionally substituted heterocyefyi and optionally substituted heteroaryl; or a pharmaceutically acceptable sail, thereof. Preferably, the molecular weight of the polymeric compound is at least 1 ,000 amu* more preferably between 1,000 amu and 50,000 amu. In a single composition, n may vary providing a mixture of polymeric biguanides.

The above polymeric biguanide compounds and methods for their preparation are described in, for example, US Patent No. 3,428,576 and East et. al., 1997.

in some .embodiments, the polymeric biguanide fox use in the invention are polymeric alkylene biguanides of the following formula (IV):

(IV) wherein n is an integer from 3 to 500, ra is an integer from 1 to 1 . especially 3 (polyarainopropyl biguanide) or 6 (poly hexame thy lene biguanidc, PHMB) and X^? and X⁴ are independently selected from -Nfi_2> -NH-C(= H)-NH-CN, optionally substituted alky], optionally substituted eycioalkyl, optionally substituted aryi, optionally substituted betcrocyclyl and optionally substituted aryi or a pharmaceutically acceptable salt thereof. In particular embodiments, n has an average value of 3 to 15, more especially 3 to 12. A suitable polymeric biguanide is sold under the trade name

Cosmocii CQ™ (Lonza),

The polymeric biguanide is present in the composition in ait amount in the range of 0.1% to 1.5% w/w, especially about 0.1% to about 1.0% w/w, more especially about 0.4% to about 0.6 % w/w of the composition .

The disperser/siirfaetant system comprises an. alcohol ethoxyiate and an alkyi glycoside or alkylpolyglycoside.

In particular embodiments, the alcohol ethoxyiate is a C Kw_.sakohol ethox iate, especially a Cu-iealeohol ethoxyiate and more especially a

alcohol ethoxyiate group. In particular embodiments, the alcohol ethoxyiate comprises 6 to 16 ethoxyiate groups, especially about 10 to 14 ethoxyiate groups. An. example of a useful- alcohol ethoxyiate is CI 2-15 Parefli-12™.

The alcohol ethoxyiate is present in the composition in an amount in the range of 0.1 % to 1.0% w/w, especially 0.2 to 0,8 % w/w, more especially aobut 0.4 to 0.6 % w/w of the composition.

In particular embodiments, the aikyiglucoside or alkylpolyglycoside is a C₈..i6

aikyiglucoside or alkylpolyglycoside, or a mixture thereof, in some embodiments, the aikyiglucoside or alkylpolyglycoside is selected from eajpryiyl giucoside-, caprylyl/capryl gkicoside, octyl gkicoside, decyl giucoside, dodecyl giucoside, coco giucoside, lauiyi gkicoside, capry.lyl polyglycoside, caprylyl/capryl polyglycoside, decyl polyglycoside, dodecyl

polyglycoside, coco polyglycoside and lauryl polyglycoside.

The alkyl giucoside or alkylpolyglycoside is present in the composition in an amoun in the range of 0.1 % to 0.5% w/w, especiall about 0.2 to 0.4 % w/w of the composition,

In some embodiments, particularly those applications where the sanitizing composition is for application to hands, the compositio may further comprise a moisturising, soothing, healing and antibacterial extract of aloe vera. in some embodiments, the composition ma also include other optional components such as theological modifiers, pH adjusters, lubricants, humeetams, fragrances and dyes. Suitable rheological modifiers include hydroxyethyJeellulese, hydroxypropylcellulose and carbapol. Suitable pH. adjusters include buffers, acids and bases. For example, a suitable acidic adjuster is acetic acid and a suitable basic adjuster is ammonium hydroxide. Suitable lubricants or humectants include, for example, glycerin. Fragrances include essential, oils and s nthetic fragrances to provide the desirable odour. Dyes may also be include to impart a suitable colour to the composition.

The compositions of this embodiment do not include alcohol such as ethanol or methanol as a component.

Without being limited b theory it is believed that, when the germ-killing-liquid- substance reaches the user's hands, the actual bioctdes do not bond effectively to the user's skin. However, according to the preferred mixture containing the disperser, it is believed that the bioeides can effectively bond to the disperser which, in turn, is able to effectively bond to the user's skin. Thus, it is believed that the preferred mixture works because She disperser aids in effectively bonding the biocide to the user's hands.

Advantageously, the apparatus is able to coat the user's hands with a very thin layer of gertn-kiiling-liquid-substance that contains far less active germ-killing agent, than would be the case if the disperser, that is in the germ-ki lf ing-liquid-substance, were not used.

Furthermore, in a further modified embodiment, without being limited by theory, a reason as to wh far less gem-killing active ingredient is required on the hands is believed to be the result of a synergy between (i) the usage of the three-dimensional filter 41 OA, and (ii) the preferred presence of the disperser in the modified germ-ki ling-iiquid-substance.

According to (he theory, this synergy is a result of the air being cleaner due to the operation of the three-dimensional filter 41 OA. A consequence of that operation is that fewer germs are blown onto the user's hands from the airflow 200C. Therefore, a smaller amount of germ-killing-ltq id-substance is required to be transmitted onto the user's hands. It will be understood by the skilled person that a sufficient amount of the biocide substance is required mostl to focus on killing germs on the user's hands, and since the airflow 20 C itself has already been purified inside the apparatus, it is believed that less germs make it onto the user's hands and hence a smaller amount of germ-killing agent is required.

However, it is notionally more difficult to evenly spread such, a smaller amount of gerai- iiing-liquid-substaace over the surface of the user's hands. Therefore, an advantage of the disposer is believed to be that it aids in the dispersal of this smaller quantity of substance over the user's skin.

ft is further postulated that the synergy also is a result of the faster airflow afforded by the three-dimensional filter 41 OA. The faster airflow, from, the three-dimensional filter 41 OA, provides more physical force to spread the disperscr across the user's hands while the user exposes his hands to the airflow. This may explain why less gcrm-killing-Iiquid-substanee is required to sufficiently coat the user's hands with an adequate, thin layer of germ-killing substance.

Moreover, another result of the observed advantageous results of the apparent synergy is thai the sufficient coating of the user's hands can be achieved by a shorter burst of spray of the germ-killing-liquid-substance into the airflow 2G0C

Furthermore, in the modified embodiment, a smaller amount of active germ-killing- liquid-substance is required. Therefore, in terms of the sensation that the user feels on his hands in practice, the user may feel that his hands have less material coating. Subjectively, this smaller amount of material on the user's hands may caitse the user to perceive that his iiands feel less sticky after the anti-bacteria material is applied to the hands.

In another aspect of the invention, the there is provided an germ-killiug-liquid-substanee suitable for use in a human-activity-environment air-purifying apparatus as described above. Such compositions comprise:

(i) an alkyi silyl ammonium fihn-forming compound;

(i i) a benza!koniura or benzethonium chloride;

(lit) a polymeric higuanide; and

(iv) a glycol carrier.

in some embodiments, the alkyi silyl ammonium film-forming agent is a compound of formula (1);

i;R :_>Si-A-N^÷( )(X){Y)] M^" (I)

wherein each R₍ i independently selected from hydrogen and^■■■(". ,.a;k l.

A is a C) ._calkyiene group;

W and X are independently selected from -Chalky!;

Y is a Cio-ajalkyl group; and

M is an anionic counterion.

In particular embodiments, one or more of the following applies;

¾ is hydrogen, methyl or ethyl, especially methyl or ethyl, more especially methyl;

A is a C^alkylene group, especially -C¾CFijC¾-; VV and X are independently selected from methyl and ethyl, especially methyl;

Y is Cio-:«alkyl; especially C_!0alky! or Cisalkyl, more especially Ci»aikyi; and

M is selected from F\ Cl^~, Br^" and 1 . especially CI^".

In particular embodiments, the alkyl silyl ammonium film-forming compound of formula (J) is selected from 1 -octadecanamm nn-N,N-di eihyh^

(also known as 3-triniethoxysi]Yipropyl-N, -din3ethyl-N-octadecyl ammoeium chloride), 3- riethoxysj|ylpropyl- ,N-diraethyl-N-octadecyl ammonium chloride, 34riethoxysilyIpropyi-N,N- dimethyl-N-isodecyl ammonium chloride or 3-trimethoxysi3ylpropyl-N,N-diaiethyl-N-isodecyl ammonium chloride.

In some embodiments, the alkyl silyl ammonium film-forming compound is present in the composition in an amount of 0.1% to 1.5% w/w, especially about 0,5% to 1.0% w w, more especially about 0.5 to 0.9% w/w of the composition.

The benzalkomum or benzethionium chloride compound is a compound of formula (II):

wherein R₂ and Rs are independently selected from Chalk ! and

R is Cs-igalkyl or H H₂CH₂0)2 4-(l-a memyl-3-dimet!i5?lbutyI)plienyIJ.

in particular embodiments, one or more of the following applies:

R₂ and R? are independently selected from methyl or ethyl, especially meiliyl; and

R₄ is selected from C¾, C-_!i C_i2, C^, C_K> or C_lg alkyl or mixtures thereof or -(CH₂C.H₂0)2i_.4~(l - dimethyl -3 -dim ethyl buty l)phe tr Ϊ j .

The ben/aikonium or benxthionmni chloride compound is present in an amount in the range of about 0.1% to 1.0% w/w of the composition, especially about 0.1% to about 0.5 % w/w, more especially about 0.1 to 0,2 % w/w of the composition.

In some embodiments, the polymeric biguanide is a compound of formula (HI):

( i ll )

wherein Z is absent or art organic divalent bridging group and each Z may be the same or different throughout the polymer; n is at least 3, preferably 5 to 20 and X' and X⁴ are

independently selected from ~NH₂, -NH-C(=NH)«NH-CN, optionally substituted alkyl, optionally substituted cyeioalkyl, optionally substituted aryl, optionally substituted heterocyelyl and optionally Siibstituted heteroaryl; or a pharmaceutically acceptable salt thereof. Preferabiy. the molecular weight of the polymeric compound is at least 1 ,000 amu, more preferably between 1,000 amu and 50,000 arau. In a single composition, n may vary providing a mixture of polymeric biguaaides.

The above polymeric biguanide compounds and methods for their preparation are described in, for example, U S Patent Mo. 3,428,576 and East et. oi., 1997.

In some embodiments, the polymeric biguanide for use in the invention are polymeric alkylene biguanides of the following formula (IV):

wherein n is an integer from 3 to 500, m. is 1 to 10, especially 3 or 6, and X⁵ and X⁴ are

independently selected from -NH.₂, -NH-C(=N.H)-NH-CN, optionally substituted alkyl, optionally substituted cycioalkyl, optionally substituted aryl, optionally substituted heterocyelyl and optionally substituted aryl or a pharmaceutically acceptable salt thereof, in particular

embodiments, n has an average value of 3 to 15, more especially 3 to 12. A suitable polymeric biguanide is sold under the trade name Cosmocil CQ^IM (Lonxa).

The polymeric biguanide is present in the composition in an amount in the range of about 0.05% to 1..0% w/w of the composition, more especially about 0.1 % to 0.5% w/w of the

composition, more especially about 0.1 % to about 0.3% w/w of the composition.

The carrier is a glycol carrier, in some embodiments, the glycol carrier is selected from dipropyiene glycol tripropylene glycol, propylene glycol and polyethylene glycol. In particular embodiments, the glycol carrier is dipropyiene glycol Dipropyiene glycol is an isomeric mixture of glycol compounds .including 4-oxa-2,6-heptaiidiol, 2-(2-hydropyproposy)propan-l-ol and 2-(2- fcydroxy- 1, -m ethy lethyoxy)propan - 1 -ol .

The carrier is present in an amount in the range of 40% to 99% w/w of the composition, especially 40% to 70% w/w of the composition, more especially about 50% to 65 w/w of the eo iposition, The compositions of the invention may further comprise fragrances. The fragrances may be any fragrance desired to provide ihe desired background smell. Suitable fragrances include synthetic fragrances, natural fragrances, essential oils and mixtures thereof. Some suitable fragrances include citrus oils such as orange, lime, lemon, tangerine, grapefruit, floral scents such as jasmine, rose, gardenia; fruit scents such as mango, banana, raspberry, apricot, apple; spicy fragrances such as vanilla, cmaamon, cloves, nutmeg; fragrance oils such as ylan ylang, sandalwood, cedarwood, lemon grass, rosehip,, pepper int and eucalyptus or mixtures of any of these fragrances.

The fragrance may be present in the composition in any amount suitable to provide the level of air fragrance desired. Typically, the fragrance is present in an amount of 20% to 60% w/w of the composition, especially about 30% to 50% w/w of the composition, more especially 35% to 45% w/w of the composition.

In particular embodiments, the composition is in the form of a viscous liquid, in relation, to the above chemical compounds, the following definitions apply:

As. used herein, the term "aikyl" refers to a straigh chain, or branched, saturated hydrocarbon group having 1 to 20 carbon atoms. Where appropriate, the alkyi group may have a specified number of carbon atoms, for example. C_halk ! which includes alky ! groups having 1 , 2, 3, 4, 5 or 6 carbon atoms in a linear or branched arrangement. Examples of suitable alky] groups include, but are not limited to, methyl, ethyl, »-propyi, /-propyl., n-butyl, /-butyl, /-butyl fi- peiityi, 2-methyIbutyl, 3-methylbutyI, 4-methylbut l, »-hexyl, 2-inethylpentyl, 3-methylpentyl, 4- roethylpetiiyL 5-meihylpentyl, 2-ethylbutyl, 3-ethylhutyf heptyi, octyi, nonyl, deeyl, isodec l, urtdecyl, dodecyl and the like.

As used herein, the term "cycloalkyl" refers to a saturated cyclic hydrocarbon. The cycloalkyl ring may include a specified number of carbon atoms. For example, a 3 to membered cycloalkyl group includes 3, 4, 5, 6, 7 or 8 carbon atoms. Examples of suitable cycloalkyl groups include, but are not limited to, cyciopropyl, eyclobuiyi, cyclopeniyl eyclohexyl, cycloheptyl and cycfooctyl.

As used herein, the term "aryi" is intended, to mean any stable, monocyclic bieyclie or tricyclic carbon ring system of up to 7 atoms in each ring, wherein at least one ring is aromatic. Examples of such aryl groups include, but are not limited to, phenyl, naphihyl,

tetrahydronaphthyi, irtdanyl, fluorenyl, phenanthrenyl, biphenyl and binaphthyl

As used herein, ihe term "alkylene" refers to a divalent saturated hydrocarbon, chain having 1 to 6 carbon atoms. Where appropriate, the alkylene group may have a specified number of carbon atoms, for example, O ^alkylene includes alkylene groups having 1 , 2, 3, 4, 5 or 6 carbon atoms in a linear arrangement. Examples of suitable alkylene groups include, but are not limited to, -C¾-, -C¾CH_r, -CH,C¾CH₂- -CH₂C¾CH₂C¾-, -C¾CH₂C¾C¾CH₂- and %CH₂C¾CH₂C¾CH₂-.

The term "heterocyclic" or "heterocyclyi" as used herein, refers to a cyclic hydrocarbon in which one to four carbon atoms have been replaced by heteroafoms independently selected from the group consisting of N, >i(R), S, S(0), S(0)₂ and 0. A ^'heterocyclic ting may be saturated or unsaturated but not aromatic. A heterocyclic group may also be part of a spirocyclic group containing 1 , 2 of 3 rings, two of which are in a "spiro" arrangement. Examples of suitable heterocyclyi groups include azetidine, letrahydrofuranyl, tetrahydrothiophenyl, pyrrolidmyl, 2- oxopyiTolidinyi, pyrrolinyi, pyranyl, dioxolanyl, piperidiny], 2-OKopiperidinyl, pyrazolmyi, imidazolinyl, thiazolinyl, dithiolyl oxathiolyl, dioxanyl, dioxinyl, dioxazolyl, oxathiozolyl, oxa olonyl, piperaz yl, rnorpholino, thiomorpholinyl, 3-oxoraorpholinyl, dithianyk triihianyl and oxa¾inyl.

The term "heteroaryi" as used herein, represents stable monocyclic, bicyclic or tricyclic ring of up to 7 atoms in each ring, wherein at least one ring is aromatic and at least one ring contains from 1 to 4 heteroatoras selected from the group consisting of 0, N and S, Heteroaryi groups within the scope of this definition include, but are not limited to, acridinyl, carbazolyl cinnolinyl, quinoxalrayl, quinazolinyi, pyrazolyl, indolyl, isoindolyi, 1 H,3H-1 -oxoisoindolyl, benzotriazoiyl, furanyl, thieny!, thiophenyl, benzothienyl, ^'benzofuranyL benzodioxane, beuzodioxin, quinolinyl, isoquinolinyi, oxazoiyi, isoxazolyl tmidazoiyl, pyraziayl, pyridazinyl, pyridinyL pyrimidinyi, pyrrolyl, tetrahydroquinolioyl, ihiazolyl, isomiazolyl, 1 ,2,3-triazolyi, 1 ,2,4-triazolyl, i,2,4-oxadiazoiyi L2,4-lliiadiazolyl, 1,3,5-iriazmyl, 1 ,2,4-triazinyl,

1,2,4,5-tetrazinyl and tetrazoiyl. Particular heteroaryi groups have 5- or 6-fttenibered rings, such as pyrazolyl, iuranyt, tbienyl. oxazoiyi, indolyl, isoindolyi, lH,3H-l-oxoisoindoiyl, isoxazolyl, imidazolyl, pyrazinyi, pyridazinvl, pyridinyl, pyrimidinyi, pyrrolyl, thiazo!yi, isothiaxolyl, 1,2,3- triazolyl, 1,2,4-triazolyl and L2,4-oxadiazolyl and 1,2,4-thiadiazolyl.

Alk i, cyeloalkyl, heterocyclyi heteroaryi and aryl groups of the invention may be optionally substituted with 1 to 5 groups selected from OH, OCi,₆alkyl, CI, Br, F, I, H₂, NHfCV _fiaikyl), fC^ai ylE SH, S^ lk l, C0₂H, C0₂C^aikyl,€ΟΝΗ₂. CONH(C_!-eialkyl) or CONiC^alkyl),.

As used herein, the term "divalent bridging group" refers to a radical that has a valence of two and is able to bind with two other groups. Examples of suitable divalent bridging groups include but are not limited to -{€¾)■- where t is an integer from i to 10, -0-. -S-, a divalent saturated or a matic carbocyclic rin or a heterocyclic Or licieroaromatic ring or a: combinatio of stich. divalent and/or cyclic moieties. For example a saturated C<s cyclic group would include -CSH^'H,-, a C₆ aromatic group would include -C_&H₄-, a C₆ heterocyclic group would include

and a€>, heteroarorriatic

Other divalent bridging groups include alkylene groups (-CHj-)_t in. which one or more carbon atoms have bees

In a preferred embodiment the divalent bridging group is -((%)_»- where t is an integer from 1 to 10, especially 1 to 6, more especially 6.

The compounds of the invention may be in the form of pharmaceutically acceptable sails. It. will be appreciated however that non-phannaeeuiically acceptable salts also fall within, the scope of the invention since these may be useful as intermediates in the preparation of pharmaceutically acceptable salts or may be useful during storage or transport. Suitable pharmaceutically acceptable salts include, but are not limited to, salts of pharmaceutically acceptable inorganic acids such as hydrochloric, sulphuric, phosphoric, nitric, carbonic, boric, sulfamic, and hydrobrornic acids. Of salts of pharmaceutically acceptable organic acids such as acetic, propionic, butyric, tartaric, raaleic, hydroxymaieic, fumaric, maleic, citric, lactic, mucic, gluconic, benzoic, succinic, oxalic, phenylacetic, methanesulphomc, toluenesitlphonic, beitezenesulphonic, salicylic sulphanilie. aspartie, glutamic, edetic, stearic, palmitic, oleic, lauric, pantothenic, tannic, ascorbic and valeric acids.

Base salts include, but are not limited to, those formed with pharmaceutically acceptable cations, such as sodium, potassium, lithium, calcium, magnesium, ammonium and

alky laramoni urn.

Basic nitrogen-containing groups may be quaterni¾cd with such agents as lower alkyl halide, such as methyl, ethyl, propyl, and butyl chlorides, bromides and iodides; dialkyl sulfates like dimethyl and diethyl sulfate; and others. As described above, the combinations of quaternary ammonium compounds may be carried in solvent or aqueous water-based compositions. When an aqueous composition is used, a disperser or surfactant system is required. When a solvent-based composition is used, no surfactant or disperser is required.

The water-based compositions are preferably used when the compositions are sprayed out of a hand dryer 1 onto the user's hands, a solvent-based systems may give a sticky sensation on the user's hands, in an exemplary embodiment, an aqueous water-based antibacterial composition is contained in the internal reservoir container thai resides inside the reservoir shell 701 in figure 10.

Solvent-based compositions are preferred when fragrances are added to the compositions, particularly in embodiments where the composition is to be used in an air purifying apparatus in locations thai are exposed to the fast air flow within the apparatus, for example:

at a location in Figure 8B where a fluid reservoir 610 with a wick 600 is provided to infuse material into the airflow;

at a location in Figure 6G were the filter structure is provided with an external rack 430 for carrying pieces of fragraiiee-eff tsing material 431 , or pieces of air-diffusible germ-kiiliiig- subsiartces, to be effused into the airflow; and

at a location where blocks of gel of air-diffusible germ-killing-substances are housed inside the filter interior 41 1, in Figure 6B.

In locations such as the above three examples, where fast airflow is encountered within the apparatus, the alternate use of a water-based substance is found to experience faster evaporate over a shorter period of time, thus having the .inconvenience of requiring more frequent replacement.

Without wishing to be bound, by theory, it is thought that the positive charges of the quaternar ammonium compounds attracts the negatively charged microbe particles in the air (hereinafter, in this specification and claims, defined and referred to as ''quaternary-microbe attraction" and may be related to the Zeia potential of the biocide substance). When the microbes come in contact with the quaternary ammonium compounds their cell membranes are ruptured causing the microbes to die. The dead microbes are bonded to the quaternary ammonium compounds and are heavier, gentl dropping out of (he air and bonding to the surface they fall on. This prevents re-entry of the dead microbe into the air.

Referring to Figure 6G. the external rack 430 may be modified to hold a fibrous matrix in position above the filter 41 OA, as shown with such modifications in. drawings Figure 6GA and Figure 6GB . Figure 6GA is a perspective view of an embodiment of a farther modification to the three-dimensional filter of Figure 6A in which the filter structure is provided with a modified external rack 430A that is able to hold a removable cartridge 431 A, In Figure 6GB, the cartridge carries a fibrous matrix 432 that is shaped like an oval with an aperture therein, akin to the shape of a running-track. The fibrous matrix 432 is impregnated with anti-bacteria substance, in a solvent-based form, comprising the quaternary ammonium compounds. The fibrous matrix 432 is positioned over the top of the filter 41 OA. As air rushes out of the top of the filter 41 OA, the quaternary ammonium anti-bacteria substance from the matrix 432 is infused into the airflow coming out of the filter 41 OA.

Figure 6GB is a view of the modification of Figure 6GA shown with the fibrous matrix cartridge 431 A fitted in place.

The matrix cartridge 431 A of Figure 6GA acts as a carrier which is impregnated with the solvent-based compositions comprising the quaternary ammonium compounds. Thus, as clean air exits the top of the three-dimensional filter 41 OA, the last, clean airflow from the filter 1 O A. becomes infused -with the quaternary ammonium, compounds. This causes the interior surfaces of the hand dryer 1 to become progressively coated with the solvent-based quaternary ammonium compounds. This anti-bacterial coating on interior surfaces of the dryer 1 performs an ongoing role of killing off any bacteria that could happen to ente the sealed dryer 1 in. spite of function of the filter 41.0A. The anti-bacterial coating of the quaternary ammonium compounds also kills germs that can enter the dryer 1 when the apparatus is manually opened for servicing.

in Figure: 8B, the fluid reservoir 610 with a wick 600 may he filled with solvent-based compositions comprising the quaternary ammonium compounds to be infused into the airflow that enters the fan-easing 400. This causes the interior surfaces of the fan and fan housing and the passageway 1 to become progressively coated with the anti-bacterial quaternary ammonium compounds, and a small amount of the compounds may end up being coated on the user's hands to kill germs there. This coating on the user's hands has potential to continue killing germs that may come in contact with the user's hands when, after using the hand dryer 1 , the user, for example, touches the door handles of a public toilet on the way out.

Thus, in the embodiment, quaternary ammonium compounds are infused into the airflow, at one or preferabl more locations in the dryer 1 , It is appreciated that the interception and killing of germs at the filter 41 OA already will have killed most of the germs in the airflow. Hence, the .further infusion of quaternary ammonium compounds into the airflow, within the apparatus, enhances the likelihood of any germs inside the apparatus being killed . This helps to achieve, as close as possible, a germ-free environment within the apparatus. This would be particularly useful when embodiments of the invention ate used in hospitals and surgical environments where the absolute minimisation of the presence of germs is a premium benefit.

Given that the quaternary ammonium compounds arc being infused into the airflow to end up as a coating on internal surfaces, in some embodiments the sensitive electronic and electrical components inside the apparatus may be coated with a sealant to protect the electrical parts from the anti-bacterial compounds.

Without wishing to be bound by theory, it is thought that infusion of the quaternary ammonium compounds into the airflow is able to make use of the said quaternary-microbe attraction to kill any germs in the airflow and on interior surfaces of the dryer 1 .

In the modified embodiment, the reservoir in the reservoir shell 701 may also be filled with the quaternary ammonium compound carried in an aqueous water-based composition. As m entioned above, the water-based compositions of the quaternary ammonium are preferabl used when the compositions are sprayed out of the hand dryer 1 onto the user's hands.

When the water-based compositions of the quaternary ammonium of the spray reaches the hands, the outgo ing fast, gemi-free airflow 200C evaporates the w ate content of the spray, leavin a small amount of quaternary ammonium compo und remaining on the user's hands. This amount of anti-bacteria substance is able to continue killing germs which may come into contact with the user's hands when, for example, after using the hand dryer 1 perhaps in a public washroom, the user's hands touch the toilet door handle when exiting the washroom.

In the embodiment, it is noted that the airflow that emanates from the three-dimensional filter 4 IOC is already substantially free of germs. Without wishing to be bound by theory, it is thought that the infusion of the quaternary ammonium compounds into that airflow, that is already substantially free of germs, enhances the action of the quaternary-microbe attraction, it is thought that the quaternary ammonium compounds, in the embodiment, are not being relied on to kill the majority of germs entering the dryer .1. That role of killing the majority of germs is the role of the main filter 4 IOC. Instead, it is thought that the quaternary-microbe attraction of the quaternary ammonium compounds is being utilised to il any remaining germs in the airflow, so as to enable to apparatus to achieve as close to a completely germ-free airflow as possible.

Without being bound by theory, it is thought that the quaternary ammonium compounds of the present embodiment, with their quaternary-microbe attraction, are highly effective when utilised in this substantially germ-free airflow⁷ that emanates from the three-dimensional main filter 4 I OC. It is believed to be a factor that enables embodiments of air-purifyin apparatus, whether embodied as hand dryers or mere air purifiers for example, to achieve as close as possible to a completely germ-free outgoing airflow. Fogging device

Figure 20 is an end view or underside of a modified embodiment viewed from beneath when the apparatus is mounted on a wall or upright surface. In the present modified embodiment, the gcrm-MUing-substaiice-effuser is in the form of a geim-Irilling-s«bstance-foggcr, embodied as fogging-apparatus 770, shown, in Figure 21 . The fogging-apparatus 770 is adapted to create a fog of ultrafme droplets of liquid in the ambient air about the embodiment of the air purifier.

Figure 21 is a perspective, cut-away view of internal components of the fogging- apparatus of Figu re 20.

Figure 22 is a cut-away, detailed view of a portion of^" Figure 21 showing sections of the fogging: device in greater detail.

A thin tube 757 connects the logging-apparatus 770 to the internal reservoir and its reservoir shell 701. The fogging device is activated by the eccentric drive and the rocking arm 763, in a similar manner to the earlier described embodiment

The pressin motion of the rocking arm 763, as described in the earlier embodiment, causes a small quanti ty of liquid from the internal reservoir, in the form of droplets, to fall on a fogging device in the form of ultrasonic fogging plate 758D. The plate 758 is connected to a source of electricity by wires. The ultrasonic fogging plate 758D is held and supported by a rubber rim 759. The ultrasonic fogging plate 758.D is provided with micro-holes through which the droplets, which arc converted into a list, can emerge from the fogging-apparatus 770, as shown in Figure 20.

In the embodiment, the logging plate 758D comprises a ceramic piezoelectric transducer that vibrates at a very high frequency, for example, 1.6 MHz. The high frequency, ultrasonic vibrations turn the droplets into a cloud or fog. The minute size of water particles of the fo , produced by such high frequency vibrations, is far smaller than carl be achieved by the mechanism of spray ing.

When the fog is released into the human-activity-environment, surrounding the air- purifying apparatus, the fog spreads into the ambient air. The fogging-apparatus 770 may be provide with a fan to disperse the fog.

Without wishing to be bound by theory, it is thought that infusing the quaternary ammonium compounds, in the form of a ultrafme Fog, actually enhances the mechanism referred to as the quaternary-microbe attraction for killing germs i the immediate environment around the apparatus. The fog of the quaternary ammonium compounds has subtly different characteristics compared to a spray of droplets of the same compounds. Without wishing to be bound by theory, it is though* that the smaller droplets in the fog would better enable the quaternary-microbe attraction to take place to kill germs in the air. It is also thought that the smaller particles of the fog will tend to hang in the air longer than the larger droplets of the spray. Being in the air flow long periods allows the fog particles to be available for killing germs using the quaternary- microbe attraction for a longer period of time before falling to the ground.

In various embodiments of the invention- the liquid from the internal reservoir 701 can. be either released using the alternate mechanisms of the spray aperture 758 or fogging apparatus 770.

It is envisaged that embodiments o f air-puri fying apparatus, tha t are in the form of hand dryers 1 , may make use of a spray aperture. It is thought that the fester propulsion of larger droplets of the spray would better enable the quaternary⁷ ammonium compounds to be projected further from the location of the apparatus, thus achieving a genn-kiUfng effect over a wider area of the humao-activity-emoronmeut that surrounds the apparatus.

It is also envisaged that embodiments of air-purifying apparatus, thai are in the form of air purifiers, without a hand-dryin function, may make use of a fogging apparatus to use the fog to purify the ambient air.

In other embodiments, however, both mechanisms of the spray aperture 758 or fogging apparatus may be incorporated in the one apparatus in order to gain the benefits of each of these methods of effusion of anti-bacteria liquid, for example, the quaternary ammonium compounds.

In this specification, the references to airflow are understood to be when the respective embodiments are installed and in operation, ft is also understood that an embodiment is capable of generating an airflow, but would not be ready to do so until it is installed and put into operation.

Embodiments of the present invention relates particularly, but not exclusively, to hand dry ers and air purifiers, and can be embodied in other apparatus, that in vol ve air-purifying, that draw in air from a human-activity environment, and expel that air purified back into the ambient environment, for example: hair dryers, vacuum cleaners, air fans, air conditioners, refrigerators, vacuum cleaners and clothing tumble dryers, to name a few non-limitin examples. Figure 18 shows a schematic diagram of an arrangement of use of an embodiment of the three-dimensional .filter stmcture in a vacuum, cleaner 1 C. The vacuum cleaner has a motor and fan 400, 405 that draws an airflow into the apparatus through a pipe 801. The air enters a main collection chamber 800 where the dirt is collected, and then enters into a three-dimensional filter structure in the form of a thfce-dimensional filter 410C. The filter 410C is in connection with the inlet aperture 10! of the vacuum cleaner via the main collection chamber 800. Thus, the main chamber 800 filters out filters out large particulate, and then the three-dimensional filter 4J.0C is used to remove germs and odours, as per the description of the threc-dimensiooai filter 41 OA in relation to earlier embodiments. Furthermore, embodiments may have one or more inlet apertures, and one or more outlet apertures. The phrases "^"an inlet" and "an outlet" includes modifications also may have multiple inlet apertures and/or multiple outlet apertures.

In this specification, the word germ is used as a generic umbrella term that includes both bacteria and viruses.

The embodiments have been advanced by w ay of example only , and modifications are possible within the scope of the invention as defined by the appended claims.

In this specification, where the words comprise or comprises or derivatives thereof are used in relation to elements, integers, steps or features, this is to indicate hat those elements, integers, steps or features are present but it is not to be taken to preclude the possibili ty of other elements, integers, steps or features bein present.

Claims

CLAIMS:

1. A human-actraty-em'ironraent air-purifying apparatus thai draws in. an airflow from an ambient human-activity-environment,, kills germs in the airflow within the apparatus and expels the airflow puri fied back into the human-aclivity-environmcnt, the apparatus comprising:

a housing bayin an interior chamber into whic an airflow enters through an inlet and from which interior chamber the airflow is expelled through an. outlet;

an airfiow-germ-kiliing-system adapted to kill germs in the airflow;

an airflow-generator which causes the airflow to flo from the inlet to the outlet;

wherein die airflow-gcrni-killing-system includes a germ-killing-siibsianee-elTuser thai effuses genn-kxlling-liquid-subsiance into the airflow,

and wherein the germ-killing-liquid-substanee comprises at least one antimicrobial agent.

2. An apparatus of claim 1 , wherein the at least on antimicrobial agent is a quaternary ammonium salt.

3. An apparatus of claim 2, wherein the quaternary ammonium salt is an alkyl dimethyl benzyl ammonium chloride.

4. An apparatus of any one of claims 1 to 3. wherein the genn-kltling-liqiiid-siibstance further comprises a second antimicrobial agent.

5. An apparatus of claim 4 wherein the second antimicrobial agent is a quaternary ammonium salt.

6. An apparatus of claim 5 wherein the quaternary aifimoniiun salt is selected from a dialkyl dimethyl ammonium chloride or an alkyl silyl ammonium film-forming compound.

7. An apparatus of claim 6 wherein the alkyl silyl ammonium film-forming compound is selected from 3-lrimethoxysilylpropyl- ,N-dimethyl-N-oeiaclecyl ammonium chloride, 3- triethoxysilylpropyl- _? -dimethyl-N-octadecyl ammonium chloride, 3-trieihoxy silyl propyl-Ν,Ν- dimethyl- -isodecyl ammonium chloride and 3-tnmedioxysilylprOpyl-N_tlSl-ditnethyl-N-isodecyl ammonium chloride.

8. An apparatus of an one of claims 1. to 7, wherein the gerni-kil!i g-liqafd-substatice further comprises a third antimicrobial agent.

9. An apparatus of claim 8, wherein the third antimicrobial agent is a biguanide

1 . An apparatus of claim 9, wherein the biguanide is poly-hexamethylene biguanide or polyaminopropy! biguanide.

1 ! . An apparatus of any one of claims 1 to 7, wherein the germ4d1ling iquid-sitbstance further comprises a dis e ses

12. An apparatus of claim 1 1 wherein the disperse? comprises an alkvlgUicoside or polyaikylglycoside and/or an alcohol ethoxylate.

13. An apparatus of any one of claims 1 to 12 wherein the germ-killing-liqutd-substance further comprises an aqueous carrier.

14. An apparatus of any one of claims 1 to 10, wherein the germ-kiiUng-iiquid-substance further comprises a solvent carrier.

15. An apparatus of claim 14 wherein the solvent carrier is a glycol.

16. An apparatus of claim 15 wherein the glycol is dipropykne glycol .

17. An apparatus of claim 1 wherein the germ-kil Img-Hquid-substanee is a compo sition comprising:

i) an alkyl silyl ammonium .film-forming compound;

ii) a benz&lkonium or benzethoniiim chloride;

vi^'i) a polymeric biguanide: and

viii) a surfactant system comprising:

a. an alcohol ethoxylate; and

b. an al.kylg.liiCosi.de or alkylpo^'lyglyeoside.

.1 . An apparatus of claim 1 wherein the germ-killing-liquid-substance is a composition comprising:

(v) an alky! silyl ammonium film-formin compound;

(vi) a bcnAilkonium or benzethonium chloride;

( vti) a polymeric biguani.de; and

(vi i ) a glycol carrier.

1 . An apparatus of an one of claims 1 to 18 wherein the airilo\v-genn-fcilling-systei¾ includes a three-dimensional filter structure having air-filter-surfaces that define a filter interior region therein and encompassed by the air-filter-sitrfaces of the filter structure, the encompassed fitter interior region, in use, positioned in connection with the inlet so that airflow entering the inlet is dispersed into the interior chamber in multiple directions exclusively through the air-filter- surfaces of die three-dimensional filter structure,

wherein the air-filter-surfaces comprise multiple layers of different filter material, and wherein the multiple layers of the atr-filier-surfaces comprise a sequence of layers from nearest to the filter interio region to furthest from the filter interior region as follows;

,ij a germ-killing filter layer thai carries germ-kiliing-substance; and

it) a germ-kiliing-substance interception filter layer that intercepts or substantially intercepts the germ-killing-substancc.

20, An apparatus of an one of claims 1 to 19 wherein the germ-killing-substanee-effuser includes a gcrm-killing-suhstancc-sprayer that sprays the germ-killing-liquid-substance into the airflow.

21, An apparatus of any one of claims 1 to 19 wherein the germ-killmg-substance-e ffuser includes a germ-kiliing-substance-fogger th at uses ultrasonic vibrations t create a fog of the genn-kil iin g-liqui d-substance .

22. An apparatus of any one of claims 1 to 19 wherein the germ-killing-sitbstance-eftiiser includes a germ-killing-substance-cartridge that holds a fibrous matrix that is impregnated with the germ-killing-liquid-substance, and wherein the germ-killing-substance-cartridge is adapted, in use, to be attached, to an exterior portion of the three-dimensional filter structure to enable the gerui-kiilifig-liquid-substance in the fibrous matrix to be exposed to the airflow emanating from the filter.

24. An apparatus of any one of claims 1 to 19 wherein the gemi-killing-substance-efmser is in the form of a wick-delivery-system where the germ-kHling-Iiquid-substance effuses off a wick.

25. An apparatus of an one of the preceding claims wherein the germ-kill ing- liquid- substance has a characteristic of quaternary-microbe attraction when killing germs in the airflow.

26. Use of a germ-killing-iiquid-sabsiance in a humaii-activity-eimrormient air-purifying apparatus that draws in an airflow from an ambient human-activity-environment, kills germs in the airflow within the apparatus and expels the airflow purified back into she hunian-aeii ity- eavironmeni, the apparatus comprising:

an. airflow-germ.-kiHing-sy.stem adapted to kill germs i the airflow;

an airflow-generator whic causes the airflo to How from the inlet to the outlet;

wherein the airflow-germ-kilimg-sysiem includes a germ-kiMing-substance-effuser that is able to effuse genn-killmg-liquid-substance into the airflow,

and wherein the germ-kiliing-liqnid-substance comprises at least one antimicrobial agent,

27. Use of a germ-kiliing-iiqxiid-substance of claim 26, wherein the at least one antimicrobial agent is a quaternary ammonium salt.

28. Use of a germ-killmg- iquid-substance of claim 26 or 27, wherein the at least one antimicrobial agent includes a .first ami microbial agent comprising alky] dimethyl, benzyl ammonium chloride and a second antt microbial agent comprising didecyi dimethyl ammonium chloride or an alky I sil l film-forming^■ammonium compound.

29. Use of a germ-kiiling-Hquid-substance of any one of claims 26 to 28 wherein the germ- ^'killing-liquid-substance has a characteristic of quaternary-microbe attraction when killing germs in the airflow,

30. A. method of spraying at least one antimicrobial agent onto and spreading the agent over a user's hands, the method comprising; spra ing a germ-kill .mg-liqiiid-substanee usin a human-acuViiy-eaviroaiment ak- purifying apparatus that draws in an airflow from an ambient hiaaan-activity-envirotmient, kills germs in the airflow within the apparatus and expels the air flow purified back into the buman- activity-environment, the apparatus comprising:

art airflow-germ-kHUng-s stera adapted to kill germs in the airflow:

wherein the airi ow-germ-killing-system includes

that is used to effuse the genn-killmg-liquid-substance into the airflow,

and wherein the geim-killing-liquid-substance comprises at least one antimicrobial, agent and a disperser,

and wherein the germ-kiliing-liquid-substance comprises at least one antimicrobial agent and a disperser, and the method includes using the airflow and the disperse to spread the at least one antimicrobial agent across the user's skin of the hands.

31. A method of claim 30 wherein the airilow-germ-killing-system includes a three- dimensional filter structure having air-filter-surfaces that define a filter interior region therein and encompassed by the air-filler-surfaces of the filter structure, the encompassed filter interior region, in use, positioned in connection with the inlet so that airflow entering the inlet is dispersed into the interior chamber in multiple directions exclusively through the atr-fiker-surfaces of the three-dimensional filter structure

32. A method of claim 30 or 31, wherein the at least one antimicrobial agent is a quaternary ammonium salt and the disperser comprises an alky] ghicoside and/or an alcohol ethoxylate.

33. A me thod of any one of claims 30 to 32 , wherein the gemi-killi.ng4iquid-substan.ee comprises a first antimicrobial agent comprising alkyi dimethyl benzyl ammonium chloride and a second antimicrobial agent comprising didecyl dimethyl ammonium chloride or an alkyi silyl ^■film- forming ammonium compound.

34. A method of any one of claims 30 to 33, wherein the disperser comprises one or more of decyiglucoside, octylglucoside or capryl caprylyl glucoside.

35. A method of any one of claims 30 to 34, wherein the gemi-kiiling-f iqutd-siibstaiice comprises a third antimicrobial agent.

36. A method of claim 35, wherein the third antimicrobial agent is a biguanide.

37. A method of claim 37, wherein the biguanide is poly-Iiexamethylene biguanide or polyarrtinopropyl biguanide.

38. A method of any one of claims 33 to 37 wherein the germ-killing-liquid-suhstance has a characteristic of quaternary-microbe attraction when killing germs in the airflow.

39. A hinnan-activity-environment air-purifying apparatus that draws in aft. airflow from an ambient httmaa-ac vity-eavironmen^ kills germs in the airflow within the apparatus and expel the airflow purified back into the hurasn-activity-envit^'oflment, the apparatus comprising:

a housing ha ving an interior chamber into which an airflow enters through an inlet and from which interior chamber the airflo is expelled through an outlet;

an air ow-gerni-kii!ing-system adapted to kill germs in the airiiow, the airilow-gerrii- killing-system including a three-dimensional filter structure comprising air-filter-sitrfaces that define a filter interior region therein and encompassed by the air-filter-surfaces of the filter structure, the encompassed filter interior region, in use, positioned in connection with the inlet so that airiiow catering the inlet is dispersed into the housing interior chamber in multiple directions exclusively through the air-fiiter-surfaces of the three-dimensional filter structure, the air-filter- surfaces comprise multiple layers of different filter material, and wherein the multiple layers of the air-fil er-surfaces compri e a sequence of layers from nearest to the filter interior region to furthest, from the filter interior region as follows:

i) a germ-killing filter layer that carries germ-kiiling-stibstance; and

ii) a germ-kiUing-substance interception filter layer that intercepts or substantially intercepts the germ~ki Ring-substance; and

wherein the apparatus comprises germ-kiiling-subsiance-effuser in the form of a gerni- kiiling-substanee-fogger tha uses ultrasonic vibrations to create a fog o gerrn-killing-!iquid- substance in the hum n-activity-enyironnient about the air-purifyisg apparatus.

40. An apparatus of claim 39 wherein the germ-killing-liquid-substance comprises at least one antimicrobial agent.

4 ! An apparatus of claim 40, wherein the at least one antimicrobial agent is a quaternary ammonium salt.

42. An apparatus of any one of claims 39 to 41 wherein the germ-killing-liqiiid-substanee has a characteristic of quaternary-microbe attraction when killing germs in the air.

43. A hui aii-activiiy-environmcnt air-purifying apparatus that draws in an airflow from an ambient hiramn-activity-enwonment. kills germs in the airflow within the apparatus and expels the airflow purified back into the hiiraan-activity-environraent, the apparatus comprising:

a housing having an interior chamber into which an airflow enters through a inlet and from which interior chamber the airflow is expelled through an outlet;

an airfiow-germ-kil!ing-systerri. adapted, to kill germs in the airflow:

wherein the airflow^;-genrf-killing-system includes a gcrm-killing-substance-sprayer that sprays germ-killing-liquid_^substance into the airflow,

and wherein the gerni-kiiling-iiquid-substance comprises at least one aaiimicrobial agent.

44. An apparatus of claim 43, wherein the at least one antimicrobial agent is a quaternary ammonium salt.

45. An apparatus of claim 44, wherein the quaternary ammonium salt is an alkyl dimethyl benzyl ammonium chloride.

46. An apparatus of any one of claims 43 to 45, wherein the germ-kilUng-liquid-subsiance further comprises a second antimicrobial agent.

47. An apparatus of claim 46 wherein the second antimicrobial agent is a quaternary ammonium salt.

48. An apparatus of claim 47 wherein the quaternary ammonium sal is selected from a dialkyl dimethyl ammonium chloride or an alkyl silyl ammonium film-forming compound.