US3610589A - Humidifier - Google Patents

Abstract

Apparatus for humidifying air by rotating evaporative material supported within a water reservoir while flowing air through the material. A baffle in the upper portion of the humidifier separates an air inlet opening from an air outlet opening. The air introduced into the humidifier at the air inlet opening is directed by the baffle from the top of the humidifier through the evaporative material and out the air outlet opening.

Description

United States Patent [72] Inventor William P. Paulln Barrie, Ontario, Canada [21] App]. No. 763,520 [22] Filed Sept. 30, 1968 [45] Patented Oct. 5, 1971 [73] Assignee Canadian General Electric Company Limited Toronto, Ontario, Canada [54] HUMlDlFIER 9 Claims, 4 Drawing Figs.

[52] U.S. Cl 261/30, 261/92, 55/234, 55/400, 55/473 [51] 1nt.C1 F24f3/14 [50] Field otSearch 261/83, 84, 30, 92, 72; 55/234, 400, 473

[56] References Cited UNITED STATES PATENTS 1,961,508 6/1934 Persons i. 261/92 2,432,755 12/1947 Hanson 261/92 2,875,846 3/1959 Yonkers 55/354 3,274,993 9/1966 Martin 261/92 3,352,297 11/1967 Martin et 261/92 3,474,598 10/1969 Keuls 261/92 3,480,209 11/1969 Stilesm. 261/92 2,584,618 2/1952 Robic 261/92 Primary Examiner Frank W. Lutter Assistant Examiner-Bernard Nozick Attorneys-Lawrence R. Kempton, Leonard Jv Plait,

Frederick P. Weidner, Jr., Frank L. Neuhauser, Oscar B. Waddell and Melvin M. Goldenberg ABSTRACT: Apparatus for humidifying air by rotating evaporative material supported within a water reservoir while flowing air through the material. A baffle in the upper portion of the humidifier separates an air inlet opening from an air outlet opening. The air introduced into the humidifier at the air inlet opening is directed by the baffle from the top of the humidifier through the evaporative material and out the air outlet opening,

THE; 1 (1.55238 PATENTED mm 5 :97:

SHEET 1 UF 2 dun-42g Attorney PATENTEDUBI Si n sumaurz IN V/iN'lh/z, W1 lll'am F? Paulin Attorhgy IIUMIDIFIER BACKGROUND OF THE INVENTION This invention relates to humidifiers and in particular to portable humidifiers for use in the home.

In some of such humidifiers, air is passed directly through a wetted evaporative material in order to effect transfer of the moisture to the air. Usually, the material is in the shape of a drum or a belt having a portion thereof submerged in a water reservoir so that as the drum or belt moves, it is wetted. The drums and belts now are mostly made of a foam plastic.

One difficulty in the design of such humidifiers is to construct drums and belts wherein the foam plastic provides an optimum evaporation surface area but a minimum restriction of the airflow therethrough so that a maximum amount of moisture is added to the airflow. Another difficulty in the design of humidifiers intended for use over long periods of time is the handling of the mineral deposits particularly lime particles which remain behind on the wetted evaporative material when the water is evaporated therefrom. Unless the water is distilled, these deposits will always be present thus requiring frequent cleaning in order to sustain efficient operation of the humidifier. This and also the growth of odor producing organisms in the water and on the wetted evaporative material makes the maintenance of this type of humidifier unpleasant and difficult for the consumer.

SUMMARY OF THE INVENTION In accordance with the present invention, there is provided a portable humidifier comprising a housing including top, side, front and rear walls. A water-filled reservoir occupies the lower portion of this housing from which it may be removed in the manner of a drawer. An evaporative material preferably in the form of a drum is rotatably supported within the reservoir and partially submerged in the water therein. Air inlet and air outlet openings provided in the upper portion of the housing are separated by a baffle means which extends from the top wall of the housing downwardly towards the evaporative material supported within the water reservoir and terminates short of it thereby dividing the upper portion of the housing into two compartments. Drive means are located in one of the compartments for rotating the evaporative material and providing an air flow from the air inlet opening through the evaporative material to the air outlet opening.

It is an object of this invention to provide a high efficiency, portable humidifier which utilizes as the wetted evaporative material a plastic foam preferably formed into a drum which can easily be removed from the humidifier for cleaning purposes without the use of tools.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective rear view of the new humidifier with the water reservoir partially pulled out;

FIG. 2 is a perspective view of the drive and baffle means whereby the humidifier housing is omitted and the baffle means partially cut away to expose the drive means;

FIG. 3 is an enlarged, partial view in the direction indicated by arrow A of FIG. 2, and

FIG. 4 is a schematic side view into the interior of the humidifier.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, there is shown a humidifier cabinet or housing from the rear thereby exposing rear wall 11, sidewall I2 and top wall 13. Housing 10 is preferably rectangular in shape but can be given other shapes if so desired. The rear wall II covers only the upper portion of housing 10 thereby leaving an opening in the lower portion for inserting or withdrawing a water reservoir I4 in the form of a drawer. In order to facilitate these movements, a handle I5 is provided preferably along the top edge of rear wall 16 of water reservoir 14. Evaporative material in the form of a cylinder or drum 17 is rotatably supported within water reservoir 14 by a roller 18 secured in the end walls of water reservoir I4 as seen at 19. Drum 17 and roller 18 extend substantially through the entire length of water reservoir I4 and form a unit with the reservoir which may be readily withdrawn from and returned into housing 10.

Drum 17 consists of a supporting layer 20 made of a netted plastic material which is covered by a layer of foam plastic 2I such as polyurethane foam. Two clamping strips 22 and 23 secure layer 21 to supporting layer 20. Roller I8 is also made of a plastic material. An air inlet opening 24 preferably of circular shape is provided in rear wall 11 and covered by a screen plate 25. An air outlet opening 26 occupies the major part of top wall 13 and is covered by louvers 27, 28 and 29. The louvers are provided with fixed slanting vanes and preferably are of a square shape so that they can be inserted into the air outlet opening in four different positions. This makes it possible to change the direction of the airflow emitting from the humidifier as required. In the remaining part of top wall I3, a water level indicator 30 is located which indicates the amount of water in reservoir 14. A float mechanism may be used for this purpose which extends into the reservoir and may be retracted therefrom by a handle 3|. Several switch buttons 32 are also located on top wall 13 for controlling the electrical system of the humidifier. Electrical conductor 33 is used to connect the humidifier with a source of electrical energy.

FIG. 2 illustrates the arrangement and function of the baffle and drive means within the upper portion of housing 10. A baffle 34 in the form of a box with an open bottom and an air passage opposite the air inlet opening 24 extends from the top of housing It] downwards toward evaporator drum 17 and terminates short of it. The baffle 34 divides the upper portion of housing 10 into two compartments extending across the width of said housing thereby separating air inlet opening 24 from air outlet opening 26. The compartment with air inlet opening 24 houses drive means which is secured to baffle 34. The drive means includes an electric motor 35 driving a fan propeller 36 arranged in the air passage provided by air inlet opening 24. Motor 35 is provided with a rear shaft extension 37 which is coupled to a speed reducing gear 38, for instance, a worm gear. Speed reducing gear 38 in turn drives over a shaft 39 connected thereto by a flexible rubber coupling 39a, and a friction drive pinion 40 a drive roller 41. Shaft 39 extends thereby from the speed reducing gear 38 in a downwardly slanting direction towards one end wall of boxlike baffle 34 and is rotatably secured therein.

Pinion 40 presses against a bevelled end portion 42 of drive roller 41, which is also rotatably secured in the end walls of baffle 34. Roller 41 covered with a resilient material presses against the evaporator drum I7 and causes it to rotate. Seen also in this FIG. is float 43 of the water level indicator in its retracted, inactive position from which it may be tilted into reservoir 14 about an axis of rotation 44 by handle 31 (shown in FIG. 1). This water level indicator is not part of this invention but is the subject matter of a copending U.S. Pat. application Ser. No. 763,837 of T. Ridding filed Sept. 30, 1968, now U.S. Pat. No. 3,536,032 and assigned to the same assignee as the present application.

In order to insure a proper function of the drive means at all times, several biasing means have been provided and are illustrated in FIG. 3. A leaf spring 45 secured to an end wall of baffle 34 and acting on the bearing of shaft 39 exerts a downward pressure on this shaft so that friction drive pinion 40 is kept in proper contact with the bevelled end portion 42 of drive roller 41. Similarly, a U-shaped spring 46 is connected with one leg 47 in a horizontal position to one end wall of baffle 34 so that the other leg 48 projects into the lower portion of the humidifier also in a horizontal position. The free end of leg 48 is slightly curved downwards so that when water reservoir I4 is pushed back into the humidifier housing I0, axle 19 of roller 18 may slide up the curved portion onto leg 48. As roller axle 19 is located in a vertically extending slot 49 in the end wall of reservoir 14, spring 46 exerts a pressure on roller 18 in the upward direction. The same biasing means is, of course, provided on the other end of roller 18, and therefore, drum 17 supported by roller 18 is constantly and evenly pressed against drive roller 41.

An alternative of this arrangement would be to secure supporting roller 18 in a normal, not slidable way in the end walls of reservoir 14 and employ a floating bearing at each end of drive roller 41. The floating bearings allow the drive roller 41 which may be filled with sand, to move up and down and maintain even pressure on drum 17 regardless of any deformation of the drum from a truly circular shape. The flexible rubber coupling 390 between drive shaft 39 and reducing gear 38 and the rotatable securing of drive shaft 39 and drive roller 41 to the floating bearing plate in the end wall of baffle 34 facilitate the up and down movement ofdrive roller 41. Pinion 40 and bevelled end 42 of drive roller 41 are still biased together as mentioned before but here the biasing spring would be mounted on the floating bearing plate. Finally, by allowing the opposite end of drive roller 41 to move up and down in a keyhole-shaped slot, the drive roller is removable by raising the end and urging it laterally into the enlarged portion of the slot whereby the other end becomes disengaged from the bearing plate and the roller may be withdrawn. Since this can be done without the use of a tool, it constitutes a major advantage of this arrangement.

In operation, the humidifier works as schematically indicated in FIG. 4. Motor 35 drives fan propeller 36 which draws air through air inlet opening 24 into housing 10. The air is ducted downwards by baffle means 34 and forced twice through the wetted surface of drum l7. Thereby, the air picks up moisture and is then ducted upwards and discharged through the louvers covering air outlet opening 26. Motor 35 actuates drive roller 41 through reduction gear 38 and shaft 39. Drive roller 41 which is coated with a resilient material presses against drum l7 and causes it to rotate at a predetermined speed. The rotation of drum 17 through the water in reservoir 14 traps droplets of water in the foam plastic 2| (FIG. 1) which are drawn up into the airflow produced by fan propeller 36 and evaporated. The speed of rotation of fan propeller and drum may be controlled by reducing the voltage applied to the motor by means of a tapped reactor inserted in series circuit relation with the motor. The amount of reactance is selected by actuating one of the buttons 32 (FIG. I) of a tap switch which provide high, medium and low positions and also an "off position." As the schematic view of FIG. 4 further shows, the drive roller 41 is positioned above and slightly to the rear of supporting roller 18. This and their vertical separation distance may be chosen so that drum 17 is urged toward the front of reservoir 14 and retained there. This provides an adequate space between drum l7 and the backwall of reservoir 14 into which the before-mentioned float 43 (FIG. 2) of a water level indication means may be lowered for indicating the water level on indicator 30 (FIG. 1) on top of the humidifier cabinet 10. The float 43 may also be used for actuating a water level switch which turns the unit off automatically when the level is reduced to a predetermined amount. Finally, as indicated, the direction of rotation of the drum is chosen so that it does not tend to climb up the front wall of the reservoir which otherwise would result in the drum ceasing to rotate.

The design of the described humidifier includes many advantages and improvements in operating convenience and performance. The basic arrangement of the three major subassemblies, the housing, the drive and baffle assembly and the reservoir and drum assembly provides an easy and simple way for withdrawing of the reservoir and drum assembly from the unit for the purpose of refilling the reservoir and cleaning of the drum. Of course, the refilling of the water reservoir alone could easily be achieved without withdrawing of the water reservoir from the humidifier housing by simply providing a funnel inside the housing below one of the louvers covering the air outlet opening. In such event, the funnel, preferably made of a plastic material could be mounted on the front wall of the humidifier housing immediately beneath, for instance, the middle louver. Upon removal of this louver water can then be poured into the funnel which will guide it to the reservoir. A look at FIG. 4 reveals how easily this can be done.

The drum itself is made of a foam plastic layer supported by a cylinder of netted plastic material. This keeps the plastic foam dilated and permits the use of a thin layer of plastic foam which in turn does not impede the airflow to the extent that would occur if the plastic foam were self-supporting. The plastic foam layer is also readily removable which is very important since the accumulation of lime particles on the plastic foam will eventually impede the airflow so that periodic cleaning is required. The design of the drum makes it easy for the customer to unfasten the plastic foam layer from the cylindrical netted plastic material by removing the clamping strips and then simply pulling it off the cylinder. The foam plastic layer may then be washed in a conventional manner. Finally, there is a minimum of mechanical stress on the foam plastic layer during the rotation of the drum. The foam plastic layer is rolled together with the supporting cylinder between the drive and supporting roller and the very small tangential driving force is distributed over the full length of the plastic foam cover.

The manner in which the drum is rotated between a resilient surfaced upper or drive roller and a lower or supporting roller results in a significant reduction in the tendency for lime residue to adhere to the foam plastic layer. The gentle squeezing action of the rollers loosens particles of lime adhering to the foam plastic layer and as the drum circulates through the water, the particles are flushed off and settle to the bottom of the reservoir. It is to be noted that the cleaning action is distributed over the full length of the drum so that substantially the entire surface of the plastic foam layer is cleaned.

The proper orientation of the drum in the reservoir is essential if smooth rotation is to be achieved. With the drive and supporting rollers located at the top of the drum, friction between the ends of the drum and the end walls of the tank will cause the drum to skew and may cause jamming. If, how ever, the friction is restricted to the top portion of the drum ends, skewing does not occur and for this reason the walls of the reservoir are formed inwards at their top ends (FIG. 1) to provide a sufficient clearance between the ends of the drum and the end walls of the reservoir in the critical areas. The contours achieved with this inward forming also provide smooth guides to keep the drum located in the proper posi tion.

The use of bacteriacides to control the growth of odorproducing bacteria in water reservoirs of humidifiers is well known. These materials range from common borax to blends of quaternary ammonium compounds. With the use of the latter which are the most effective types of bacteriacide for this application, the occurrence of foaming of the water in the reservoir causes the pores of the plastic foam layer to become obstructed and thereby impedes the airflow through the evaporative material. Such a reduction of airflow is undesirable because it reduces the evaporative output of the humidifier and also increases the pressure drop in the air flow and thereby increases the audible noise in the system. This foaming may be eliminated by adding antifoaming agents to the water in the appropriate amounts and the silicone emulsion type has been found to be particularly effective in this regard.

The foregoing is a description of the preferred embodiment of the invention, and variations may be made thereto without departing from the spirit of the invention, as defined in the appended claims.

What is claimed is:

l. A portable humidifier comprising a housing including top, side, front and rear walls, a drawer water reservoir occupying the lower portion of said housing, an evaporative material of porous annular form rotatably supported within said reservoir on a support roller secured to said reservoir, said reservoir and evaporative material being readily removable as a unit from and returned to the housing, air inlet and outlet openings in the upper portion of said housing, baffle means within the upper portion of the housing extending from the top downwardly towards the evaporative material within said reservoir and terminating short of it, said baffle means dividing the housing into two compartments and separating the air inlet opening from the air outlet opening, a fan propeller, mounted in the housing and drive means including an electric motor located in one of said compartments and a rear shaft extending from the electric motor and coupled to a gear reduction means, said rear shalt in turn drives a drive roller rotatably secured to said baffle means, said drive roller being mounted adjacent the evaporative material and pressing against the outer surface of said evaporative material, said motor being connected for both driving said drive roller and the fan propeller whereby the evaporative material is rotated and an airflow is produced from the air inlet opening through the evaporative material to the air outlet opening.

2. A portable humidifier as defined in claim 1 wherein the supporting roller is secured in vertically extending slots provided in the end walls of the reservoir and spring means exert a biasing pressure to the supporting roller in the upward direction.

3. A portable humidifier as defined in claim 2 wherein said drive roller is secured to said baffle means in a floating bearing so as to permit an up and down movement ofsaid roller.

4. A portable humidifier as defined in claim 1 wherein the air inlet opening is located in the rear wall and the air outlet opening in the top wall of said housing.

5. A portable humidifier as defined in claim 4 wherein the baffle means forms an open-bottomed box provided with an air passage opening in alignment with said air inlet opening.

6. A portable humidifier as defined in claim 1 wherein the evaporative material is a continuous web in the shape of a drum and said drive roller is provided with a resilient surface and extends along the full length of said drum in a substantially parallel spaced relationship to the axis of the drum.

7. A portable humidifier as defined in claim 6 wherein the drum-shaped evaporative material consists of a supporting layer made of a netted plastic material covered by a layer of foam plastic and secured thereto by clamping strips.

8. A portable humidifier as defined in claim 6 wherein said drive roller is positioned above and slightly to the rear of the roller supporting the drum within the water reservoir.

9. A portable humidifier as defined in claim 6 wherein the top ends of the walls of the reservoir are formed inwards to provide a guiding action and clearance for the evaporator drum.

Claims (9)

1. A portable humidifier comprising a housing including top, side, front and rear walls, a drawer water reservoir occupying the lower portion of said housing, an evaporative material of porous annular form rotatably supported within said reservoir on a support roller secured to said reservoir, said reservoir and evaporative material being readily removable as a unit from and returned to the housing, air inlet and outlet openings in the upper portion of said housing, baffle means within the upper portion of the housing extending from the top downwardly towards the evaporative material within said reservoir and terminating short of it, said baffle means dividing the housing into two compartments and separating the air inlet opening from the air outlet opening, a fan propeller, mounted in the housing and drive means including an electric motor located in one of said compartments and a rear shaft extending from the electric motor and coupled to a gear reduction means, said rear shaft in turn drives a drive roller rotatably secured to said baffle means, said drive roller being mounted adjacent the evaporative material and pressing against the outer surface of said evaporative material, said motor being connected for both driving said drive roller and the fan propeller whereby the evaporative material is rotated and an airflow is produced from the air inlet opening through the evaporative material to the air outlet opening.

2. A portable humidifier as defined in claim 1 wherein the supporting roller is secured in vertically extending slots provided in the end walls of the reservoir and spring means exert a biasing pressure to the supporting roller in the upward direction.

3. A portable humidifier as defined in claim 2 wherein said drive roller is secured to said baffle means in a floating bearing so as to permit an up and down movement of said roller.

4. A portable humidifier as defined in claim 1 wherein the air inlet opening is located in the rear wall and the air outlet opening in the top wall of said housing.

5. A portable humidifier as defined in claim 4 wherein the baffle means forms an open-bottomed box provided with an air passage opening in alignment with said air inlet opening.

6. A portable humidifier as defined in claim 1 wherein the evaporative Material is a continuous web in the shape of a drum and said drive roller is provided with a resilient surface and extends along the full length of said drum in a substantially parallel spaced relationship to the axis of the drum.

7. A portable humidifier as defined in claim 6 wherein the drum-shaped evaporative material consists of a supporting layer made of a netted plastic material covered by a layer of foam plastic and secured thereto by clamping strips.

8. A portable humidifier as defined in claim 6 wherein said drive roller is positioned above and slightly to the rear of the roller supporting the drum within the water reservoir.

9. A portable humidifier as defined in claim 6 wherein the top ends of the walls of the reservoir are formed inwards to provide a guiding action and clearance for the evaporator drum.

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