US3121000A - Laundry dryer or washer-dryer - Google Patents

Description

Feb. 11, 1964 J. R. HUBBARD 3,121,000

0 LAUNDRY DRYER OR WASHER-DRYER Filed Nov. 9, 1960 s sheets-sheet 1 INVENTOR.

JAA/[f #V55/MW f U/Pod Feb. 11, 1964 .1.R. HUBBARD LAUNDRY 'DRYER 0R WASHER-DRYER 3 Sheets-Sheet 2 Filed Nov. 9, 1960 Feb. 1,1, 1964 J. R. HUBBARD 3,121,000

LAUNDRY DRYER 0R WASHER-DRYER Filed Nov. 9. 1960 5 Sheets-Sheet 3 f4 :7 .if 7J Z? 1 I l '111111111111111 @if M I 72 45.- l /f 7f /fa V l E f a 7; s, I Q 7 n f United States Patent O Fried Nov. 9, 1960, ser. No'. 68,232 1 claim. (ci. 34-7s) This disclosure relates to improved apparatus for drying fabrics. The improvement is of particular utility when applied to a domestic combination washer-dryer.

The drying of fabrics has always been rather slow and has often been questionable as to the degree of dryness achieved. Although it is known that different fabrics have different requirements in thas respect, the public has long and generally desired a machine which could extract more humidity, in less time, from a given load of laundry. The industry has tried various arrangements for this purpose, but improvement of the drying eifect has still been desired. Such improvement is therefore an object hereof.

It is a further object hereof to construct the machine so that it occupies a minimum of space. This is important since users generally want the dryer or washer-dryer to be in compact form suitable for incorporation in a group of kitchen appliances.

The improved machine uses a new and distinctive arrangement of tub closure and bearing support plates for the fabric tumbling drum, this arrangement being such that, between said plates, a widely expanded iilm flow of cold condensing water is contacted with a turbulent sheet or current of flowing air, which air is prevented from entraining and short circuiting such condensing water. By these expedients the extraction of humidity is greatly promoted, although only a limited space, narrowly conned by the bearing support plates, is used for this operation.

These and other characteristics of the new machine can best be explained by means of a drawing which is therefore appended hereto. FIGURE 1 is a perspective rear view of a machine incorporating this invention. FIG- URE 2 is a generally similar but exploded view of internal parts of the machine. FIGURE 3 is a sectional view taken along line 3-3 in FIGURE 1. FIGURE 4 is another sectional view, taken generally along line 4-4 in FIGURE 1, while FIGURE 5 is an enlarged fragmentary view of a detail from FIGURE 4.

FIGURE 6 is a view generally similar to that of FIG- URE 4 but showing a modied embodiment of the invention. FIGURE 7 is an enlarged fragmentary view of a detail from FIGURE 6.

As shown in FIGURES 1 and 2, a pair of generally vertical, generally circular plates 10, 11 are disposed in coaxial arrangement, with central and body portions thereof axially spaced apart and with peripheral or rim portions thereof joined together, thereby providing not only a tub wall structure but also providing space for a condensing chamber or channel 12 between these plates. This channel as shown comprises a pair of channel portions or branches 13, each on one side of a bearing structure 14 for a tumbling drum. The bearing structure is shown as a cylindrical housing which has longitudinally spaced portions supported by the two plates and 11.

Each side or branch 13 of channel 12 has an aperture 15 in its lower portion, whereby air from a rear portion of vthe laundry tub 16, generally closed by plates 10, 11, can enter this channel 12. An upper central portion of this channel, on the other hand, has an air outlet port 17 therein (FIGURES 3, 4), and this port, by means of a straight horizontal duct 18, communicates with a front portion of tub 16. Thus the air circulating systems, provided in accordance with the invention (FIGURE 1), consists of horizontal duct 18, the interior of tub 16, and vertical channel 12. A blower 19 (FIGURE 2) is installed in a recess 19-A of back plate 11, with its suction side communicating with air outlet port 17 of channel 12, and this blower circulates the air forwardly to the front of tub 16, rearwardly through the tub, and then upwardly through the newly arranged condensing channel between plates 10, 11.

The blower can, as shown, be actuated in conventional manner, for which purpose a belt system 20 is disposed on the rear surface of back plate 11, this system being driven by a motor 21 mounted on a lower part of tub 16, as best shown in FIGURE 1.

The unit structure of tub 16, channel 12, duct 18, and drive means 20, 21 is suitably suspended in a frame 22, which also supports the panels 22-A forming the cabinet structure of the machine (FIGURE 3). A resilient suspension is used if the machine shall serve as a washerdryer, with centrifugal extraction prior to hot-air drying, and in such event the tub structure must be small enough to allow some vibratory motion of the suspended tub unit in and across the panel structure 22-A. Particularly in domestic dryers and washer-dryers, the space for this panel structure or cabinet is usually limited, thus imposing corresponding limitations on tub structure 16, includ` ing back plate and condensing channel structure 10, 11. As a result, the dimensions of this latter structure are limited in typical cases of plain domestic dryers and particularly in the case of domestic washer-dryers with resilient suspension. It is therefore necessary to make the entire, integral channel, tub and duct structure 12, 16, 18 as compact as possible. By means of the new arrangement this has been found to be possible; in other words, sufcient tub, channel and duct space is still provided to allow effective, rapid completion of a laundering and drying program, applied to a given weight of fabrics.

The new arrangement, which provides this advantageous result, is characterized in part by the way in which it brings the condensing water into contact with the air. For the purpose of drying this air, a small inlet pipe 23 (FIGURE 2) discharges cold water into the upper central portion of the condensing channel, while a lowermost portion of this channel provides an outlet 24 `for used condensing water. The cold water of course serves to rid the circulating air, which comes from the laundry tub 16, of an admixture of humidity which has been extracted from the fabrics by this circulating air. For the purpose of such extraction the air is heated by a heater 25, disposed in horizontal duct 18 (FIGURE 4), before it enters the tub.

The cold water admitted by pipe 23 between plates 10, 11 serves also to rid the water, circulating between these plates, of so called lint which has been removed from the fabrics in the drying process, and to flush this lint out at 24. i

It is, as mentioned, a feature of the invention that most if not all of the wall structure, forming the condensing channel, is provided by the bearing support structure which forms one of the basic and almost indispensable elements of the machine. This bearing support structure comprises the generally vertical plates 10, 11 which support the bearing 14, the latter element providing rotatable support for shaft 26 of fabric tumbling drum 27, thereby supporting and actuating said drum in tub 16. The shaft is provided with a drive pulley 28 at the rear end thereof, behind back plate 11, which pulley is driven by the drive or belt system 20, FIGURES 1, 2. When drum 27 is charged with fabrics and particularly with wet fabrics and when the drum is then rotated to cause tumbling, substantial forces and stress reactions are applied to the drum and the supports thereof, including shaft 26, bearing 14 and the bearing supports. For this reason it has been usual and necessary even in the absence of any condensing system to provide rugged bearing supports, similar to plates and 11. These plates, and the new condensing channel 12 therebetween, are accordingly free of any substantial or significant coat chargeable to the condensing system, the channel being completed by simple apertures 15, 17 for the access and withdrawal of circulating air.

The upper section or recess 19A of channel 12, containing the blower 19, includes a chamber 29 which receives the discharge of the blower and connects the blower with heater duct 18. This duct, as shown, conducts the heated air to an orifice ring 30, in a front portion of the tub, through a passage 31. Drum 27, revolving in tub 16, is of course formed with suitable perforations 32, for admission and/or removal of the circulating air. The air circulation is indicated by broken arrows in FIGURE 1. In the other figures this air circulation is distinguished from the water circulation, the currents of air being accordingly shown by open arrows 33 and those of water by plain arrows 34.

Within the new condensing channel 12, as best indicated in FIGURE 3, this air circulation 33 is directed upwardly from air inlets to air outlet 17, whereas a generally downward flow of condensing water 34 passes through this channel from water inlet 23 to water outlet 24. It is further important to note that in accordance with the invention, the condensing water owing through channel 12 is caused to take the form of a wide and thin, downwardly flowing film 34A, passing over the inside surface of condensing channel wall 10, as best indicated in FIGURE 5. The significance of this maintenance of a film flow of condensing water can be outlined as follows.

Theoretically, a variety of procedures could be used to extract humidity from fabrics by circulating air and thereafter to remove such humidity from the air itself. It is for instance known for the latter purpose to spray atomized cold water into moist, hot lair and thereafter to collect and remove such water. However, any effective use of atomized water must be based upon the utilization of a cooling tower effect, and such an effect requires the use of very large tower space, compared with the space usually available in a domestic appliance of the present type. It has been found, in other words, that prior attempts to use atomized condensing water in fabric dryers, which have minimized the time period allowed for the desired degree of drying, have required excessively large dryer tubs, unsuitable for installation in compact cabinets. When, on the other hand, a smaller installation was used and an attempt was made nevertheless to dry the air by atomized water, this has required unduly extended periods of drying time, such as 120 minutes or more for conventional drying of washed and centrifuged laundry material.

Other attempts have therefore been made, heretofore, to condense the vapors contained in the air which circulates in the dryer. In some such attempts a flow of condensing water has been applied in form of a thin film, flowing for instance over inside surfaces of the tub. In such latter attempts, however, another difficulty has thus far been encountered, which seems to be connected with the problem of enforcing positive contact of all particles of air, having vapor therein, with the cold water film used as a condensing medium. The film flow of condensing water was potentially able to provide very etfecitve drying, but the air to be dried was not positively and adequately contacted therewith.

The latter difficulty was specially pronounced and the drying period specially long when an attempt was made to provide the air-water contact in the tub itself (in which case it has also been attempted to dispense with power driven blowers altogether and to use the condensing water itself as a kind of pumping medium; the pumping efficiency of such a medium was found to be low and much of the water shortcircuited through the machine without ever coming into adequate contact with the air to be dried). In the atomizing machines, on the other hand, too much of an air pumping and liquid entraining effect was applied to the drops and droplets of water, which were thereby removed from the condensing contact zone prematurely.

The invention, by contrast, provides not only the widely distributed, guided film fiow 34A of condensing water in channel 12 but also an overlying, directed, sheet-like current 33A of turbulent air, contacting but not entraining said film of water (FIGURE 5). These combined currents, passing through the vertical channel 12, not only provide a maximum of drying effect, in av minimum of time, but also allow the use of minimum space for this purpose, thereby both allowing and most effectively applying the use of the wide but narrow space 12, between closure plates 10, 11 of a compact tub 16, as a condensing channel.

The way in which the film flow 34A of condensing water is formed, in accordance with a specific feature and aspect of this invention, is indicated in FIGURE 5. Inlet pipe 23 for cold water 34 discharges horizontally against the central portion of a water spreading wheel or disc 35, disposed in an upper central portion of condensing channel 12. The shaft 36 of blower 19 extends from blower drive pulley 37 to and beyond the blower itself and toward a recess 10A of the inner vertical plate 1f), where it carries and rotate this wheel or disc 3S. A rim portion of this wheel or disc is arranged to receive the water from the central point of impingement and to discharge it centrifugally, thus forming a thin film of water which flows outwardly -across the gap between the rotating spreader wheel and the walls of recess 10A.

In effect, accordingly, shaft 36 operates an air blower 19 in the outlet 17 of air channel 12 and also operates a small, special impeller 35 for condensing water in the recessed, water-intercepting -wall area llt-A of said channel, opposite to and remote from said air outlet 17. 'Ihe arrangement of the water impeller and intercepting Wall is such as to create and maintain a coherent film iiow 34A, which then adheres to the walls of channel 12, thus avoiding entrainment of droplets, drops or particles of water into blower 19.

Successive operations of the machine can now be resumed briefly.

Drum 27 is initially charged with fabrics, through a door 38 of the machine, FIGURE 4, and laundering operations are then initiated by control devices, not shown. In order to dry the fabrics, operation of air heater 25 and drive system 20 is manually or automatically initiated by electrical switching means lforming part of said control devices, thereby rotating fabrics drum 27, air blower 19, and, according to the invention, condensing water spreading twheel 35, whereto water is admitted through inlet pipe 23 by a suitable valve, not shown.

The condensing water 34, centrally applied by pipe 23 to spreader wheel 3S, is centrifugally accelerated by and discharged from the rim of this wheel in form of a thin, substantially unbroken film of water, flowing outwardly. This flowing film or sheet of water impinges on wall 10, in recess 10A, wherefrom it continues to flow, still in form of a film 34A, FIGURE 5, in directions including outward components. Advantageously the arrangement and operation are such that this ilm vflow covers substantially the entire Iwidth of each side or branch 13` of condensing channel 12, as is generally indicated in FIGURE 3.

In further accordance with the invention, the circulating air 33 drawn from tub 16 ows upwardly th-rough condensing channel 12 in form of a lflat sheet 33A of turbulen-tly moving air, FIGURE 5, which proceeds generally countercurrently to the film yflow 34A of condensing water, the air filling substantially the entire channel 12 so that all portions of the air are etfectively contacted with the widely distributed film of water. This form of air current is enforced by the generally flat design of channel space 12 between inner and outer bearing support plates 1t?, 11. Advantage rather than harm is thus derived from the fact that the space available for the machine and particularly for the bearing plate structure 10, `11 is limited in forward-rearward directions. The new arrangement provides a form of air-water contact, without atomization of water, which appears to cause a maximum of condensation of steam within a minimum of space. It does so, as mentioned, at substantially no extra expense for the wall structure providing the boundaries of the required space, said wall structure being required also for the closure 4of the tub and the support of the drum bearing.

Preferably, a lrn or sheet of liowing condensing water is formed not only on the rear surface of the inner wall 1@ but also on the front surface of the outer back plate 11 in channel 12. For this purpose the peripheral velocity of spreader disc 35 and the flow velocity of the sheet 3511A of water, adjacent this disc, are made rapid enough to cause a substantial portion of the water to flow upwardly along the inner plate and rearwardly along the underside of the connecting or rim structure in the condensing channel, as is schematically indicated in the upper part of FIGURE 5. This latter portion of condensing water then Iforms a Ifilm flow 39' which passes downwardly along and over the inside surface of back pla-te 11. Said surface is provided with an upstanding annular lip 40 around the rim of suction inlet 17 of blower 19, so that the film 39' of condensing water is caused to ow around this suction inlet and not into the same.

This latter arrangement is important as it is desired to minimize entrainment of condensing water into a blower 19. Heretofore, as already mentioned, attempts have been made to extract humidity from the air circulating in a laundry machine by injecting cold water into the blower which circulated this air. According to the present invention, by contrast, the entrance of any particle of condensing water into the blower is not only dispensed with but positively avoided for the reasons which have been stated. The condensing water is caused to form ilowing ilms 34A, 39, which lms are contacted but not atomized or entrained by the air to be dried.

Incident to the drying process the air contained in the machine is circulated a number of times by means of blower 19, FIGURE 4, and the circulating air is exposed to the action of heater 2S on each pass from the blower to the tub, in order that the air be able to cause evaporation of humidity from the fabrics in drum 27. On each pass the air is then conducted through channel 12 as a turbulent, iiat, widely distributed, generally upward ow, in contact with the equally distributed, relatively slow, downward film ows of condensing water. When this is done, extremely rapid and complete drying results within the wide Ibut otherwise limited region 12, provided by the back plate and channel structure 10, 11.

In the modified embodiment 22B of FlIGURES 6 and 7 the condensing channel Sil is combined with an air duct 51 leading from the discharge portion 52 of blower S3 to heater 54 and `which is provided with a pair of aperture shutter systems 55 and 56. These are arranged in such a way that either closed or open circulation of air can be used. System 5S, as best shown in FIGURE 7, comprises a portion of the wall 60 of duct S1 with an aperture 6,1 therein which can selectively be closed or opened by a shutter 6-2, pivoted at 63. When closing this aperture 611 the shutter rests against the inside of wall 60 as indicated at 64; to open the aperture it is swung about pivot 63 and it then rests against an opposite wall area 65 as indicated at 66. Swinging of the shutter from one position into the other can be eifected for instance by a double acting solenoid system 67 connected with the shutter by suitable linkage 68. Gears 69, 70 interconnect shutter 62 with shutter 71 for the outside aperture 72 in the second aperture system 56, in such a way that both systems operate uniformly and that they simultaneously open to the ambient atmosphere (thereby Ibecoming separated from one another) and that both simultaneously open to one another (thereby becoming sealed from the ambient atmosphere).

In normal, drying operation of the modified machine both shutters 62, 71 are in the position in which they close their apertures 61, 72 to the outside, as shown in full lines in FIGURE 7. They then establish connection between blower discharge area 52 and heater channel 51, see full line arrows in FIGURE 6.

At the end of the drying operation, when heater S4 is cle-energized, it usually becomes desirable to provide rapid cooling down of the entire machine. This can be achieved better with the combined use of outside air 73 and cold water 74, than by merely circulating air 75 within the previously heated machine and exposing it to the cold water. At this time, accordingly, solenoid 67 (FIGURE 7) is operated to reverse the shutter position, to shut off blower discharge area 52 from heater duct 51 and to expel used air 76 through port 72, while causing the suction of the blower to draw outside air 73 into aperture 61 and thus into the machine. Shortcircuiting of discharged and aspirated air 76, 73, between apertures 72 and 61, is avoided by suitable partition or duct work 77.

While only two embodiments of the invention have been described and shown it should be understood that the details thereof are not to be construed as limitative of the invention except insofar as is consistent with the scope of the following claim.

I claim:

In a laundry machine of the type wherein fabrics are tumbled and hot-air dried in a tub, while spent air is dried in a condensation channel formed by rearwardly spaced rear closure walls of said tub:

an air blower having a blower intake in one of said walls, in an upper part of said channel, for drawing a current of air from the tub, upwardly through said channel, and then rapidly into said blower intake for return to said tub;

inlet passage means for introducing a stream of cold water through one of said walls into said channel for condensation of humidity in said current of air, said inlet passage means having an aperture for smoothly discharging said stream of cold water in a position confronting said blower intake and in an initial direction toward the same;

a dellector wheel rotatable with the blower fan, said wheel being located in said channel and axially spaced between said blower intake and said aperture confronting it, and being constructed and disposed toV deflect the discharged stream of water from the blower intake and to reverse and to distribute the discharged and deiiected stream of cold water toward said one wall forming said stream into a thin sheet flowing away from the blower intake and outwardly onto extended areas of said walls in said channel, thereby to prevent the current of air, even in the region where it is rapidly drawn into said blower intake, from entraining the stream of water or particles thereof and from short-circuiting the same to the tub, while providing extensive contact between said water and air throughout said channel, said extended areas of said walls dening surface structure 7 for gravitational flow of said thin sheet of cold water from said upper part to a lower part of the condensation channel; and outlet means for removing used water from said lower part of the condensation channel.

References Cited in the le of this patent UNITED STATES PATENTS 1,316,745 Safford Sept. 23, 1919 i3 Rieber ell 10, Matthews et al. Apr. 16, Zehibach Nov. 29, Patterson May 21, Raczynski J'uly 23, Toma Feb. 25, Foster May 30, Mellinger June 26,

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