US2717457A - Vapor condensing clothes drier trough construction - Google Patents

Description

T. R. SMITH Sept. 13, 195.5

VAPOR CONDENSING CLOTHES DRIER TROUGH CONSTRUCTION 2 Sheets-Sheet 1 Filed April 14, 1953 INVENTQR. 772017242512. 50%

T. R. SMITH Sept. 13, 1955 VAPOR CONDENSINC CLOTHES DRIER TROUGH CONSTRUCTION Filed April 14, 1953 2 Sheets-Sheet 2 INVENTOR.

Thomas 12 51724 90, BY )%1;Jm #nx ym 9% w United States Patent VAPOR CONDENSING CLOTHES DRIER TROUGH CONSTRUCTION Thomas R. Smith, Newton, Iowa, assignor to The Maytag Company, Newton, Iowa, a corporation of Delaware Application April 14, 1953, Serial No. 348,725

21 Claims. (Cl. 34-75) The invention relates to clothes driers, and more particularly to clothes driers of the tumbler type incorporat-. ing a vapor condensing area. In principle, the present invention carries forward the improvements which comprise the subject-matter of my copending application, Serial No. 259,580, filed December 3, 1951, for Clothes Drier, and to such extent is a continuation-in-part thereof.

In its general organization, the drier of the present invention is similar to that disclosed in my copending applications Serial No. 335,184, filed February 5, 1953, for Clothes Drier, now Patent No. 2,680,915, and Serial No. 336,470, filed February 12, 1953, for Clothes Drier Water Inlet and Condenser, now Patent No. 2,680,916. It differs therefrom in the particular details of construction of the vapor condensing zone of the casing. For the details of construction and operation of the machine as a whole, reliance here will be upon the prior applications listed above to avoid unnecessary duplication of description. For details of a control system suitable for drier of the type to which the present invention is applicable, and for a heating means therefor, reference may be had to my other copending applications Serial No. 335,185 and No. 335,186, filed February 5, 1953, now Patents No. 2,682,599 and No. 2,680,914, respectively.

As is noted in my copending applications identified above, the operation of clothes driers of the vapor condensing type involves the accumulation of lint within and about the condensing section which creates a problem. If the lint accumulates to too great an extent, proper operation of the drier may be impaired, which may require dismantling of the drier to clean the same, and, in

addition, bacteria may form in the collected lint 'to cause objectionable odors.

As is set forth in my copending applications, (the lint problem is minimized when the lint can be maintained relatively warm and dry, and, hence, in a relatively mobile, nonadherent, unagglomerated condition upon those surfaces adjacent the condensing area that are not actually flushed by the flow of condensing water therethrough. in this condition, it may be moved, without theformation of clogging impacted accumulations, to the drain at the bottom of the casing through which it is discharged with the condensing water.

Among the factors contributing to this desired. resultis the maintenance of a positive thermal and moisture break between the relatively cold and wet condensing zone and the surrounding surface. upon which lint may accumulate, which, from the standpoint of optimum operating conditions, should be kept as warm and dry as- 2,717,457 Patented Sept. 13, 1955 water, and by a wicking action like that just described, cause the dry lint to become wet and give rise to the objections already noted.

The present invention is, accordingly, directed to the provision of a condensing zone for clothes driers in which the cold, wetcondensing area is flushed with cold water which is afforded unobstructed flow to the drain, and which is contained by warm, dry areas constituting the contiguous parts of the casing whichare isolated from the cold, wet area by the use of insulating materials of drying chamber. The drying chamber is heated to evap-v orate the moisture in the clothing, and a section of the lower portion of the side wall of the container is recessed to provide a trough. Water is admitted to the interior of the container and flows downwardly by gravity in a thin film over the trough to define an internal condensing area for the vapor evaporated from the clothing. The trough is preferably formed from a sheet of material having low thermal conductivity which is recessed or offset outwardly in radial directions beyond the surface of the casing to provide for an increased resistance to the thermal flow therethrough while the better to confine the condensing water therein. In one form a relatively thin strip of material is adapted to overlap the marginal edges of the trough or condensing section to define an overlapping sharp edge which is effective to restrict the tendency oflint settling on the container walls about the condensing section to draw water therefrom by capillary attraction, which results in matting'and collection of additional lint. By providing a construction of this type, plus the temperature difference maintained between the condensing section and the surrounding walls of the container, accumulation of lint about the condensing section is maintained at a minimum. In addition, in one form of the invention a heating element is disposed about the marginal edges of the condensing area to maintain the area outside the trough at a high enough temperature to prevent condensation and subsequent accumulation of lint.

Referring to the drawings:

Figure 1 is a transverse vertical mid-sectional view of.

a clothes drier embodying the invention;

Figure 2 is a fragmentary sectional view taken generally along the line 22 of Figure l, with the revoluble drum removed;

Figure 3 is an enlarged detail sectional View of the,

improved trough construction taken along the line 3-3 of Figure 2; and

Figure 4 is an enlarged partial sectional view of the trough and water inlet construction taken along line 4-4 of Figure 2.

Referring now more in detail to the drawings for an embodiment selected to illustrate the invention, there is shown a tumbler type clothes drier 10 having a horizontally journaled revoluble drum 12 mounted within a substantially imperforate stationary sheet metal casing or container 14 providing a drying chamber 16, in which the drum revolves. The container or casing is suitably supported on a base frame construction 18 by means of a web and channel structure 20, and the entire assembly is enclosed within a cabinet construction 22 to provide a pleasing appearance. For further particulars regarding the construction, details, arrangement of parts, and the operation of the machine, reference is made to my copending applications above identified.

The substantially imperforate container or casing 14 surrounding the drum includes a longitudinally extending side wall 24, whose lower sector is generally cylindrical in transverse section; the vertical rear wall 26; and a generally vertical front wall 28. All of these elements are preferably secured together at their marginal edges in any suitable manner to provide a unitary rigid structure.

In order to evaporate the moisture in the clothing, heat is supplied by a pair of sheathed electric heating elements 30 which are mounted within the drying chamber 16 beyond the outer periphery of the rotatable drum 12.

A portion of one sector of the side wall 24 of the casing 14 is blanked or cut out from a line of the plane of the axis of the drum at one side thereof downwardly to slightly beyond the lowermost portion of the casing to provide an opening 32 (Fig. 2). In this particular design, the blanked out portion does not extend for the full axial extent of the side wall, but is centered with respect thereto to leave a pair of oppositely disposed relatively cylindrical surfaces 34. The opening 32 is closed by a sheet of thin material, such as, for example, stainless steel, molded plastic, or the like, in the form of a liquid conducting member or trough 36 which includes cylindrically curved bottom liquid conducting surface 38 of somewhat greater radius of arc than the side wall 24; a generally vertical side wall 40 defining the boundary of the liquid conducting surface having an outwardly directed flange 42 coextensive with its outer edge. The flange is formed to follow the contour of the outer periphery of the side wall 24 of the casing and is secured to the latter around the opening 32 therein in any suitable manner, such as, by thermal bonding, to provide a fluid tight joint. The central lowermost portion of the trough 36 is recessed to receive an annular securing or back-up member 44 surrounding a drain opening 46 therein which communicates directly with the inlet of a centrifugal pump 48.

The upper portion of the pump housing is secured to the casing through the securing member 44. i

In this embodiment, the vertical wall 40 bounding the trough 36 is wider and longer than the blanked-out portion of the casing, so that when the trough is secured in position, the side and bottom edges of the opening 32 overlap the vertical side wall 40 of the trough to provide a sharply defined overhanging edge or ledge 50. This overlapping of the edge is such as to prevent or restrict the tendency of any lint settling on'the surfaces 34 adjacent the trough 36 to withdraw water from the same by capillary action in a manner previously mentioned.

in addition, at the outside corners formed by the flange 42 and vertical wall 40 beneath the cylindrical ing the drying operation, heats the vertical walls of the trough and the adjacent cylindrical walls of the casing to evaporate any moisture tending to collect thereon, thus to maintain them dry at all times, for purposes already mentioned.

In an unvented drier of the type disclosed, the vapor is condensed by having it directly contact the zone or area defined by the trough 36, which is directly cooled by a relatively wide, thin stream of cooling water 54 4) flowing over the the inner surface 38 of the trough. The cooling or condensing water may be supplied from any suitable source of supply, and controlled, as is fully set forth in my copending applications already mentioned. It is discharged from the downwardly directed end of a conduit 56 into a generally rectangular distribution box or receptacle 58. This receptacle is disposed in a horizontal plane with the axis of the drum, and is seof the receptacle is part of the cylindrical bottom of the trough which defines the upper end of the condensing zone.

The wall portion 60 common to both the trough and the water distributing receptacle 58 is provided with a plurality of rows of parallel and horizontally spaced orifices 62 through which the water flows by gravity during the drying operation. Covering these openings within upper end in any suitable manner. The inner wall 60 the casing is a curtain-type flap or check valve 64 made of relatively thin plastic material, preferably having nonsticking, adhesion-resistant characteristics, which is anchored to the casing along its upper end by means of a clamping strip 66. The sides and the lower end of flap are free to swing about the clamp. The condensing water readily passes through the distributing openings 62 in a plurality of small, closely-spaced streams, and flows downwardly by gravity from behind the lower free edge of the flap check valve, over the inner peripheral surface 38 of the trough forming the condensing zone in a relatively wide and thin film. If for any reason there be a tendency for the vapor pressure within the drying chamber to increase above atmospheric pressure, the internal pressure acting on the curtain check valve 64 moves it against the wall of the casing to cover the openings through with no water is flowing and prevents the escape of vapor outwardly therethrough into the interior of the cabinet. I Also, an important function of the check valve is to cover the openings at all times to prevent the accumulation of lint about the openings which may clog the same. The features of the water inlet herein shown and described are the particular concern of my application Serial No. 336,476, new Patent No. 2,680,916, aforementioned.

The lower end of the condensing zone is recessed, as previously mentioned, to provide the trap or sump for collecting the condensing water, condensate and lint. This sump has its centrally located drain outlet 46 providing the inlet of the centrifugal pump 48 which is mounted directly below the lowermost portion of the casing. The centrifugal pump is driven in any suitable way, and its discharge end is connected to a conduit 68 leading to a'suitable drain.

With an arrangement of this type, under exceptionally severe linting conditions, lint will tend to fall and collect on the side wall of the casing about the condensing zone 38. However, if this lint is maintained in a dry condition, it rests lightly thereon, and as the drum 12 rotates the vapor currents set up tend to agitate the lint and keep fit'moving until it passes over the vapor condensing trough, into which it falls and is flushed to drain. Under some conditions it may be advisable to provide a plurality of radially outwardly extending thin flexible wiper strips 7 0 secured to the outer edge of the drum 12 to wipe the surfaces 34'fre'e of lint. The strips may be pitched helically somewhat in such directions as to work the lint toward the trough. As the wiper strips are moved with the drum, they lightly contact and brush across the interior surfaces of the side wall and restrict the tendency 'for the lint to accumulate therein. These thin wiper strips are preferably formed from plastic material having the non-sticking, adhesion-resistant characteristics.

In operation, heat builds up in the chamber 16, and .the moisture in the clothing being dried is evaporated "therefrom. With the drum being rotated in a counterclockwise direction, as viewed in Figure l, the vapor is circulated about the inner periphery of the stationary casing, where a portion of the vapor directly contacts the film of cold water 54 flowing over the condensing area "38 and is condensed. This condensation of vapor develops a slightly reduced pressure about the zone and results in a flow of vapor in the direction of the cold surface where it is condensed. As the condensing and condensate water reaches the bottom of the chamber, "it flows into the sump and is discharged as previously en ned- As the vapor moves toward the condensing section of V the drying chamber to be condensed, the fine airor vapor-borne lint will be carried by the vapor and it will likewise contact the condensing water and absorb enough moisture to settle thereon. Since a continuous supply or film of water is flowing over the condensing surface 38, the lint will be washed or moved downwardly by the flowing water into the sump and be discharged to drain along with the condensing and condensed water. Likewise, the heavier lint falling out of the drum on the condensing side of the chamber is moved to the outlet along with the other lint, and the heavier lint falling from the opposite side of the drum will tend to roll downwardly into the trough for discharge also.

The trough 36, being formed of material having poor thermal conducting characteristics and being offset from the marginal walls 34 by the vertical side wall 40, the temperature difierence between the condensing zone and adjacent portions of the casing tends to be sharply defined to minimize the accumulation of lint on the surfaces 34. However, since a flat surface of this type will accumulate some lint under operating conditions, the revolving drum and/ or wiping members moving across these surfaces tend to maintain the lint in an agitated state until it is worked over and into the trough where it is discharged to drain.

In this construction, wherein the edges of the opening 32 overlap the vertical side wall 40, any lint which may settle about or adjacent the opening over the trough is not in a position to contact the vertical side wall 40 of the same, and, thus, cannot gradually build up to a point where the lint makes contact with the water, which, if

it should occur, would draw a portion of the cooling water from the bottom of the trough upwardly by capillary action. In addition, the heating elements 52 about the trough are eifective to maintain a sharp temperature difierence between the two sections to prevent chilling of the remainder of the casing below the dew point of' the vapor and to evaporate quickly any water which might be splashed out of the trough. It can be seen that the lint settling on the side wall of the drum over the exposed edge of the opening 32 has a relatively narrow contact surface to retain it should build-up of lint occur. Should it reach a certain value and contact the water, the added weight and motion will pull the accumulated lint from the edge and flush it to drain. In addition, the overlapping ledge will hold the dry lint out of contact with the side walls of the trough, and the revolving drum and/ or wipers will tend to keep it agitated and moving toward the point of discharge.

As has already been mentioned, it is important to maintain the lint outside the trough in as dry a condition as possible because, should it absorb moisture or water from the trough, matting will occur and produce an adhesive effect in causing it to stick to the casing. Once this action is initiated, there is created a rough, cold, and wet surface for collecting additional lint. The present invention, by the principles of isolating the conditions of temperature and moisture prevalent in the condensing zone from the surrounding parts, eifectively obviates these difficulties.

It is claimed:

l. A drier for damp clothing, comprising means for agitating the clothing, a substantially imperforate casing having end walls and a side wall defining a drying chamber enclosing said means, means for heating said chamber to evaporate the moisture in the clothing, a recessed trough provided in the lower section of the side wall of agitating the clothing, a substantially inperforate casing,

having end walls and a side wall defining a drying chamber enclosing said means, means for heating said chamber to evaporate the moisture in the clothing, said side wall having an opening in a portion of its lower sector, a recessed trough member secured to the outer periphery of said side wall and covering the opening, said through being of greater width than said opening so that the edges of the latter project over said trough to define an overhanging ledge, a water inlet for admitting cooling water to said trough in a thin film to condense the vapor evaporated from the clothing and to collect lint therein, and means for collecting and discharging the water and lint, said over-hanging ledge defining a barrier against the induction of water out of the trough to the remainder of said casing by capillary action.

3. A drier for damp clothing, comprising means for agitating the clothing, a substantially imperforate casing having end walls and a side wall defining a drying chamber enclosing said means, means for heating said chamber to evaporate the moisture in said clothing, said side wall having an opening in a portion of its lower sector, a recessed trough member secured to the outer periphery of said side wall and covering the opening, said trough being bounded by side walls, said trough having an overall length and width greater than said opening so that the edges of the latter project over said trough to define an overhanging ledge along its sides and lower edges, a water inlet adjacent the upper end of said trough for admitting cooling water thereto to flow through said trough in a thin film to condense the vapor evaporated from the clothing and to collect lint therein, said trough having an outlet in its lower portion for discharging the cooling water, condensate and lint to drain, said overhanging .ledge defining a barrier against capillary attraction of the liquid in said trough. to the remaining portions of the casing by lint settling on the adjacent portions of said side Wall.

4. A drier for damp clothing, comprising means for agitating the clothing, a substantially imperforate casing enclosing said means and defining a drying chamber, means for heating said chamber to evaporate the moisture in the clothing, a trough formed in a portion of said casing, a side wall bounding said trough, a water inlet adjacent the upper end of said trough for admitting cooling water to said trough by gravity in a thin film to condense the vapor evaporated from the clothing and collect lint therein, said trough having an outlet in its lower portion for discharging the cooling water, condensate and lint to drain, and means for heating said side wall adjacent the periphery of said trough to maintain a temperature difference between said trough and side wall to prevent condensation of vapor on the adjacent surfaces of said side wall.

5. A drier for damp clothing, comprising a revoluble drum for agitating the clothing, a substantially imperforate casing having end walls and a side wall defining a drying chamber enclosing said drum, means for heating said chamber to evaporate the moisture in the clothing, said side wall having an opening in a portion of its lower sector, a trough member secured to the outer periphery of said side wall and covering said opening to provide a fluid tight connection, a water inlet adjacent the upper end ofsaid trough for admitting cooling water to said trough in a thin film to condense the vapor evaporated from the clothing and collect the lint therein, said trough having an outlet in its lower portion for discharging the cooling water, condensate and lint to drain, and means for heating said casing adjacent the periphery of said trough to maintain a temperature difference between said trough and the remainder of said casing and to maintain any of the lint settling adjacent the trough in a dry condition.

6. A drier fordamp clothing, comprising a revoluble drum for agitating the clothing, a substantially imperiorate casing having end walls and a side wall enclosing said means and defining a drying chamber, means for heating saidchamber to evporate the moisture in the clothing, a trough formed in a portion of the lower sector of said side wall,'a water inlet adjacent the upper end of. said trough for admitting cooling water to said trough by gravity in a thin film to condensethe vapor evaporated from the clothing andcollect a portion of the lint there- 'in, said trough having an outlet-in its lower portion for discharging .the cooling water, condensate and lint to drain, and means for heating said side wall adjacent the periphery of said trough to maintain a temperature difference between the lower portion of said trough and said side wall adjacent the periphery of said trough, said drum being eflective to agitate the lint settlingon the side wall adjacent the periphery of said trough until the lint contacts said trough.

'7. A drier for damp clothing, comprising a revoluble drum for agitating the clothing, a substantially imperferate casing having end walls and a side wall enclosing said drum and defining a drying'chamber, means for heating said chamber to evaporate the moisture in the clothing, said side wall having an opening in a portion of its lower sector, a recessed through member including substantially vertical wall portions secured to the outer periphery of said side wall and covering said opening to provide a fluid tight connection, a water inlet adjacent the upper end of said trough for admitting cooling water to said trough in a relatively wide and thin film to condense the vapor evaporated from the clothing and collect a portion of the lint shaken from the same, means for collecting and discharging the cooling Water, condensate and lint to drain, an overhanging ledge disposed about the trough to prevent lint settling on its vertical wall portions from contacting lint settling on the side wall of said casing, and heating means carried about the periphery of said trough to maintain said vertical walls and adjacent side walls free of moisture.

8. A drier for damp clothing, comprising a revoluble drum for agitating the clothing, a substantially imperforate casing having end walls and a side wall enclosing said drum and defining a drying chamber, means for heating said chamber to evaporate the moisture in the clothing, said side Wall having an opening in a portion of its lower sector, a recessed trough member including substantially vertical wall portions secured to the outer. periphery of said side wall and covering said opening to provide a fluid tight connection, the area of said trough as defined by said vertical wall portions being greater than the area of said opening whereby the edges of the latter constitute an overhanging ledge around said trough, a Water inlet adjacent the upper end of said trough for admitting cooling water thereto to flow by gravity over said trough in a relatively Wide and thin film to condense the vapor evaporated from the clothing and collect a portion-of the lint shaken therefrom, means for collecting and discharging the cooling water, condensate and lint to drain, and heating means disposed about the periphery of said trough to heat said vertical portions and overhanging ledge to maintain the same free from moisture.

9. A drier for damp clothing, comprising a revoluble drum for agitating the clothing, a substantially imperforate casing having end walls and a side wall enclosing said drum and defining a drying chamber, means for heating said chamber to evaporate the moisture in the clothing, said side wall having an opening in a portion of its lower sector, a recessed trough member including substantially vertical wall portions secured to the outer periphery of said side Wall and covering said opening to provide a fluid tight connection, the area of said trough as defined by said vertical wall portions being greater than the area of said opening to provide an overhanging ledge around said trough, a water inlet adjacentthe upper end of said trough for admitting cooling water thereto .to flowvby gravity over said trough in arelativ'elywide. and thin film-to condense the vapor evaporatedfrom the clothing and collect a portion of the lint'shaken therefrom, means for collecting and discharging-cooling Water, condensate and lint..to drain, and .heatingmeans .disposed about the periphery of saidv trough to heat. said ivertical wall portions and overhanging ledge to maintainsaid portions and ledge free from moisture-rtopreventeapillary attraction of the cooling Water to other portionsofsaid-casing bylint tending to accumulate over and undersaidledge; said revolving .drum. being effective to,. agitate thelintwithin the casing .until. the. lint passes over. andcontaetsxthe water flowing in said trough.

10. In a drier having atcasing defining a chamber for drying damp.fabrics,.meansfor heating said chamber to evaporate .themoistureinsaid fabrics, an opening insaid casing, atrough haviflgLside portionsnand a bottom portion coveringsaid. opening, the. sidet-portions of said .trough disposing said :bottom;.- portion :thereof in offset relation to said casingadjacent said opening, said trough being formed of material having substantially lower .thermal conductivity-.thansaid casing; and means for admitting cooling fluidtosaidtroughtocondense the evaporated moisture. frorrnsaid fabrics.

agitating'said clothing, asubstantially imperforate casing defining a drying chamber enclosingsaid agitating means, means fort heating said chamber. to evaporate the moisture in said'clothing, an-insulatedttroughron said casing to thermally isolate said.- trou'ghifrorn said casing, means for admittingcooling fluid to saidtrough to condense the evaporated moisturefromsaid clothing, means for collecting and dischargingsaid cooling fluid-from said casing, ledge meansprovided by said casing, said ledge means being contiguous to-and overhanging said trough to prevent lint from accumulating in said trough.

16. In a drier having.a;.drying.;chamber serving as a vapor source, a vapor condensercomprising. a sloping wallin part. defining;said.achamber.andextending from anelevated position in saidchambento-the"bottom of said chamber, an openingin.said.wallsubstantially vertically coextensivewithsaid wall, aiclosure for said opening offsetv outwardlyfrom saidichamber. and said wall, said closure: -being:..=larger.,in;areaithannsaidopening, an upstanding perimetric flange encompassing said 'closure, said flange being connected in watertight engagement to said wall exteriorly of said :chambertinsubstantially-uniform spaced relation to said opening.

17. The invention of claim 16, said closure and flange being of a material dissimilar to that of said'wall and offering ngreaterri resistance to the transmission of heat through its mass.

.18. Theuinvention')oiirclaimf'17, t-said flange being of least dimensionxat the elevated endof -said closure and opening and of: greatest'dimension atthe-bottom thereof measured.inadirections perpendicular to said closure.

-19. The-inventio'nuof claims '18, thezslope of said wall being. a cylindrically..concavensurzface saidiclosure likewise-being cylindricallyaconcave: but scribed on a greater radius from a V differentwenterithan :the curvature of said wall.

.20.-The invention of claimvl9 grneans'. for admitting cooling fluid adjacent the upper end of said ofiiset closure, and means adjacent thev bottom .end'of the latter constituting a sump and a drain for water delivered thereto.

21. The invention of claim 20, heating means engaging said flange exteriorly of said chamber adjacent its conjunction with said wall.

References Cited in the file of this patent UNITED STATES PATENTS 10 Schneible Jan. 16, 1923 Ford Aug. 4, 1942 Brandt Aug. 11, 1942 Reedall May 5, 1953 Hammell et al. July 7, 1953 FOREIGN PATENTS France Dec. 13, 1950

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