US2974747A - Electric precipitators - Google Patents

Description

March 14, 1961 Filed March 20, 1956 J. COOLIDGE, JR., ET AL 2,974,747

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March 14, 961 J. E. COOLIDGE, JR., ETAL 2,974,747

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U d W8 Pa Q" ELECTRIC PRECIPITATORS John E. Coolidge, In, Arlington Heights, 111., and Lincoln T. Work, Maplewood, NJ., assignors to Borg-Warner Corporation, a corporation of Illinois Filed Mar. 20, 1956, Ser. No. 572,662

2 Claims. (Cl. 183-43) This invention relates to means for separating gases and particles from the atmosphere and more particularly to a gas mask adapted for removing noxious gases and also poisonous particles from air.

In the past gas masks using canisters filled with charcoal or other adsorbing means have been used to permit the wearer to operate in an atmosphere containing noxious gases. It is now contemplated that atomic bomb explosions may also leave dispersed in the atmosphere certain radioactive particles which would be injurious if inhaled. These radioactive particles may be small enough to pass through ordinary gas mask canisters.

One of the principal problems in using the usual gas mask having a canister containing loose granules ofcharcoal is the fact that the pressure drop through the necessary volume of small charcoal granules is such as to make breathing difficult and the wearing of the mask uncomfortable.

It is accordingly an object of this invention to provide a novel air cleaning means especially adapted for use in a gas mask canister which has a very low pressure drop and which will adsorb noxious gases and also will precipitate and collect particles from the air passing through the cleaner. 7

Another object of the present invention is to provide an air cleaning apparatus in which gas is adsorbed on spaced plates which also act as electrical collecting plates for particles.

Still another object is to provide a gas mask canister that will collect both gases. and particles and yet which is small and light in weight so that it can be carried on the person. 1

Other objects are to provide a gas mask canister which is relatively inexpensive, simple to-assemble and more comfortable to wear than presently known types. 7

Among still other objects of this invention is to provide a means for supporting activated charcoal in spaced parallel plates whereby it is useful to adsorb gases and also may be used as the collector plates of an electrical precipitator. The above and further objects and novel features of the invention will more fully appear from the following detailed description when taken in connection with the accompanying drawing. It will be understood however that the description and drawing are of preferred embodiments of the invention but that the invention is to be limited only by the appended claims. In the drawing: I

Fig. 1 is aiside elevational view partly in cross-section of a gas mask canister employing the present invention, the section'being taken on the'line 1-1 of Fig. 2;

I Fig. 2 is a side elevational view partly in cross-section with the section taken on the line 22 of Fig. 1;

Fig. 3 is an elevational view of enact the canister plates of the canister shown in Fig. 1;.

.screen members.

2,974,747 Patented Mar. 14,

Fig. 4 is an elevational view of a screen from the canister shown in Fig. 1; a

Fig. 5 is an elevational view partly in cross-section of a modified form of canister employing the present inventlon;

Fig. 6 is an elevational view of a gas mask showing the canister in place;

Fig. 7 is a schematic view of one form of' power pack adapted to be used with the present-invention; and

Fig. 8 is a schematic view of a second form of power pack also adapted to be used with the present invention.

In the accompanying drawing the present invention is illustrated, by way of example, in the form of a canister for a gas mask which may replace the ordinary canister used with well-known types of face pieces to form a gas masks; but it will be apparent that the novel means employed for separating particles from the air and for also adsorbing gases will be useful in other types of apparatus for cleaning air other than gas masks.

One form of novel apparatus embodying the invention is illustrated in Figs. 1 through 4 inclusive and comprises a light compact canister for a gas mask which may be connected to a face piece as shown in Fig. 6. The canister comprises a metal or plastic container 11 which houses the electrical precipitator. The container 11 comvprises a front 12, a back 13, two ends 14 and 15, a top 1'6 and a bottom 17. Secured to the inside of the front 12 of the container is a slotted plate 18 of insulating material and a similar slotted plate 19 is secured to the back 13 of the container. Supported in the slots in the plates 18 and 19 are a plurality of parallel screen members 20 which are provided with small holes to prevent large particles of matter from passing through said Interleaved between the screen members are a plurality of charged collector plates 21 and 22. Plates 21 are charged with one polarity and plates 22 are charged with the opposite polarity by means to be described later. The collector plates 21 and 22 comprise a metal supporting plate which is preferably constructed of aluminum because of its light weight. Secured to the top and bottom of the metal supporting plate 21, 22 is a layer of adsorbing material 24. It is preferred that this adsorbing material be activated charcoal which is secured to the top and bottom of the supporting plate 23 bymeans of an adhesive. We have found that charcoal granules of the order of 6 to 14 mesh fixed to the metal plates provide a satisfactory adsorbing surface. Other satisfactory structures include solid plates of charcoal supported on the metal supporting members or a self-supporting plate of charcoal may be used as acollector plate. Each of the collector plates 21 is generally rectangular in shape with two cars 25 and 26 projecting from one side. As is shown in Fig. 2, when the plates are assembled alternate plates are reversed in direction so that a tortuous air path is formed whereby the air passes under one side of the plate around the end of the Below the collector section are suspended a plurality ofcharging wires 29. A power pack which is not shown in Fig. 1 but may be either of the types shown schematically in Fig. 7 or 8 is positioned in the space alongside the collector section. The power pack is connected to the ribbons 27 and 28 and charging wires 29.

Air passing through the" apparatus enters in inlet 31 in the bottom of the container 11 and passes over the charging wires 29 which ionize particles entrained in the air. The ionized air then passes (as shownby the arrow) along the bottom surface of collector plate 21 around the end thereof and then back along the top surface around the end of the next plate continuing this back and forth motion through the entire canister. As the air passes over the canister plates certain gases will be adsorbed on the surface of the charcoal to which said gases are exposed. Since the collector plates 21 and 22 are charged, entrained particles which are also charged as they pass through the charging section are attracted to oppositely charged plates. Therefore, it will be seen that each collector plate 21 or 22 has a twofold purpose, namely, to adsorb certain gases and also to precipitate particles out of the air passing through the canister. The screen members 20 are provided principally to collect particles of carbon which may be dislodged from the collector plates 21 and 22 and they will also collect large particles which may be entrained in the air.

The collector plates 21 and 22 are spaced about A; of an inch apart so that a path of considerable volume is provided for air to pass through the canister and the pressure drop from inlet to outlet may be held to a minimum. With plate spacing in certain models of our canisters the pressure drop has been held to /2" of water. This compares with a standard gas mask canister containing particles of charcoal loosely arranged therein which has a pressure drop of 5" of water at maximum flow.

In Fig. 5 an alternative device embodying the present invention is shown. This comprises a gas mask canister generally cylindrical in shape and having an inlet 41 and an outlet 42 which is adapted to be attached to a face piece 43 as shown in Fig. 6. In the inlet 41 is mounted a screen 44 which collects large particles from the air entering the canister. Supported in the center of the canister and running throughout its length is a metal rod 45 which has on its lower end a charging wire 46. Supported on and electrically connected to the rod 45 are collector plates 47 which are generally annular in shape and comprise a metal supporting plate 48 having adhered to its top and bottom a layer of activated charcoal 48'. It will be noted that the collector plates 47 are smaller in diameter than the wall of the canister 40 so that the space 49 is provided between the end of the plate and the canister wall. Alternating with collector plates 47 are collector plates 50 which are secured to and electrically connected to the wall 51 of the canister 40. The collector plates 50 are also annular in shape and comprise metal supporting plates 52 with layers of activated charcoal 53 thereon. The collector plates 50 are provided with an opening in the center which is larger than the rod 45 so that a space 54 is provided between the inner periphery of the collector plates 50 and the rod 45. Between each pair of collector plates is positioned a corrugated plastic spacer 55 which serves to help maintain the spacing of the plates and also to prevent charcoal particles from falling off said plates. A perforated plate 56 supports the lowest plastic spacer.

The precipitator disclosed in Fig. 5 functions in a similar manner to that shown in Figs. 1 and 2. Particles in the air passing through inlet 41 are charged by a charging wire 46. The air with the entrained charged particles then passes in a tortuous path around the ends of the smaller plates and through the center opening of the larger plates. The air and the entrained particles are exposed to the charge on the collector plates 47 and 50 so that the particles are attracted to the charged 4 P at an ases her i a e a s on t a coa surfaces 53 of said plates. Since the charcoal is electrically conductive it is also contemplated that the plates could be made of solid pieces of charcoal rather than of metal plates supporting charcoal. The cleansed air passes from the canister through outlet 42 and into the face piece 43 where it may be breathed by the wearer.

It is contemplated that a power pack for the precipitator shown in Fig. 5 will be carried in a separate con tainer. Suitable connections will be provided between the power pack and the charging wire 46 which connections would also be to the center rod 45 thereby charging all plates 47 attached to it. The other line from the power pack would be attached to the grounded casing thereby grounding the alternate plates which are attached to it.

The power pack shown in Fig. 7 comprises a switch 60, a mechanical vibrator 61 which may be spring operated, a high voltage transformer 62, a selenium rectifier 63 and a filter condenser 64, and a battery 65. This power pack will produce approximately 2,000 to 3,000 volts. Since the output is only of the order of two microamperes there is no danger of shock to the wearer.

The power pack shown in Fig. 8 contemplates the use of transistors in order that it may be compact and light in weight. As shown the circuit comprises a point contact transistor 70, a junction power transistor 71, a high voltage transformer 72, a selenium rectifier 73, batteries 74, feed back condenser 75, and a coupling condenser 76. Either of the above mentioned power packs may be used with the precipitators that have been described.

It will be seen that by the use of precipitator collector plates covered with an adsorber such as activated carbon, we have provided a gas cleaning apparatus which will adsorb certain undesirable gases from air and also precipitate from the atmosphere entrained particles of material. Through the use of these combination collector plates the cleansing apparatus has been made small and compact and suitable for carrying on the person such as for gas mask use. Although one embodiment of the invention has been described as a gas mask canister it should be understood that the invention is susceptible of other uses such as in gas cleansing apparatus for industry.

Having described various embodiments of our invention, it will be realized that changes in the shape, arrangement and construction of the various features of the structures may be made without departing from the spirit nad scope of our invention, that the description and drawing are to be construed as illustrative only and the invention should be limited only by the appended claims.

What is claimed is:

1. A gas mask canister comprising a housing, an inlet for contaminated air; an outlet for purified air; a longitudinal conducting member positioned centrally of said housing; a plurality of first collector plates connected to and supported at spaced intervals on said longitudinal member and extending toward the sides of said housing with an opening between each plate and the side of the housing to provide an air path; and a plurality of second collector plates interleaved between said first collector plates connected to and supported at spaced intervals on said housing and provided with openings surrounding said longitudinal member to provide an air path, said collector plates having gas adsorbing surfaces, all of said first collector plates adapted to be connected to one pole of a source of power and all of said second collector plates being adapted to be connected to the other pole of a said source of power.

2. A gas mask canister is described in claim 1 wherein the gas adsorbing surface of the collector plates is activated charcoal.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Strong Dec. 16, 1919 Thompson Mar. 5, 1935 5 Wilhelm Apr. 21, 1936 Gates Feb. 1, 1938 Jacob Aug. 7, 1945 Carpenter et a1; Nov. 18,1947 Richardson 'Dec. 14, 1954 6 FOREIGN PATENTS Germany June 5, 1905 France Oct. 22, 1934 France Aug. 22, 1938 France Mar. 4, 1953

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