Humidifier

[57] ABSTRACT

A humidifier adapted for mounting on an air conduit to add water vapor to air flowing through the conduit. The humidifier includes a flexible resilient plastic tank for holding water. A plurality of screen discs is rotatably mounted in the tank. Each of the discs has a plurality of holes, which holes are aligned to allow air to flow through the discs. The discs are rotated by a motor to pick up water in the tank and place the water in an air stream. The tank is secured to an air conduit by a frame which has a plurality of fingers which extend through apertures in the tank. Wedges in the fingers hold the tank in position. The tank has a hose connected to its bottom to provide a drain for the tank. A transparent tube is connected to one end of the hose, which tube acts as a sight glass for the tank when the tube is mounted in a stored position and through which the tank may be drained when the tube and hose are lowered. The tank also has a pair of windows near the upper portion thereof to allow inspection of the interior of the tank while the humidifier is in operation.

Claims, 12 Drawing Figures

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PATENTEDM161974

SHEET 1 OF 4

3,833,922

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PATENTED&gt;16I974

3,833.922

SHEET 2 OF 4

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INVENTOR:

ELMER J. MQELREATH

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Attorneys

PATENTE0M16I974

3,833,922

SHEET 3 OF 4

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Attorneys

PATENTED*!! 61974

3.833.922

SHEET U OF 4

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Attorneys

3,823,922 picking up additional water vapor. Even when the flow is parallel to the planes of the screens, the amount of water which is evaporated from the raw edges is increased.

The use of apertures in a screen disc provides an effective solid screen for the water carried on the screen. It may be appreciated that the screen could be a disc having radial slots from the outer periphery to the center. However, water droplets along the edge of a radial slot tends to run down along the edge toward the center of rotation, thereby removing the water on the raw edge without evaporating. Furthermore, the disc is substantially weakened by the slots since there is very little material at the center where the slots converge. By the use of apertures in the body of the screen, there is no opportunity for water to run along an edge toward a drive shaft. Rather, the water droplets are held on a raw edge of the screen or on the main body thereof in an air stream to achieve maximum vaporization.

Cleaning of the present humidifier is greatly simplified by making the humidifier readily removable. The main portion of the humidifier may be removed from a supporting surface by first removing a plurality of wedge fingers, which wedges hold the humidifier in place, to allow the humidifier to drop down. It may be appreciated that reassembly of the humidifier is facilitated by the use of these fingers since the fingers are simply pushed into the apertures. Then, the wedges are driven into the fingers to provide a tight seal between the humidifier and a supporting portion. This may be contrasted with the customary method of supporting a device on a sheet metal duct or other support, whereby sheet metal screws or bolts are used with a nut. It is very difficult to align a nut initially, especially when the humidifier is being mounted by a person without assistance. The operator must hold up the humidifier, align the nut, and drive the screw or bolt at the same time.

The subject humidifier arrangement also facilitates cleaning of the humidifier. A thorough cleaning may be performed once the humidifier is removed; however, intermittent cleaning is accomplished by periodic draining. Once the humidifier is removed from its mount, it is a relatively simple matter to remove the minerals which have collected in the humidifier. The humidifier tank is constructed in such a manner that the screen discs may be easily lifted out of the tank so that the discs remain as a unit. The minerals which adhere to the tank are simply removed by flexing the tank to break the minerals and release the minerals from the tank. A reasonable amount of minerals on the screen discs promotes evaporation from the discs. When the mineral build-up is too great, so that evaporation is impeded; the inexpensive screen discs are discarded.

As a convenience for draining the tank, the instant humidifier has a hose connected to a drain aperture in the bottom of the tank. A transparent tube is connected to the free end of the hose, which tube is removably connected to the tank at a point above the level of the water in the tank. This transparent tube provides a sight glass for ready viewing of the level of the water in the tank to see that the tank has sufficient water and to inspect the condition of the water to determine whether the water should be drained and replaced with fresh water.

It is therefore a principal object of the present invention to provide an improved humidifier construction

HUMIDIFIER

BACKGROUND OF THE INVENTION

The use of humidifiers in buildings during the winter 5 season is well-accepted in view of the fact that medical authorities generally agree that is more healthful if the relative humidity in a building were kept at a selected level rather than the practically desert conditions which occur when cold air from the outside is raised to 10 a normal room temperature. In the ordinary operation of a humidifier, such as that disclosed in U.S. Pat. No. 3,190,624, water is added to a tank. A water carrier is provided for lifting the water from the tank and passing air through or near the carrier so that the water is evap- 15 orated into the air stream. Customarily, the water which is used in a humidifier is ordinary tap water. In many localities, especially where the tap water is well water, the water has an extremely high mineral content. As the water is evaporated from the water carrier, the 20 minerals are left behind so that the minerals are left on the water carrier and in the tank which holds the water. After a season’s use of a humidifier, the water carrier is often encrusted with minerals and the tank is also filled with the minerals. If the humidifier is not cleaned 25 for a substantial period, the tank and water carrier become so encrusted with minerals that the humidifier is no longer efficient in adding water vapor to an air stream.

A humidifier which may be used in a home installa- ³⁰tion must be compact, that is, it must be able to add a substantial amount of water vapor to an air stream, but it must not take up much space. This is especially true for installations in a home Central heating system where the home does not have a basement. In many homes ³⁵without a basement, a forced hot air system is installed in a closet or small utility room wherein space is at a premium and it is difficult to add a humidifier to an existing installation. Thus, the humidifier, though compact, must be highly efficient in order to add a suffi- ⁴⁰cient quantity of water vapor.

The humidifier which is added to an existing system must be easy to install and to be removed easily for cleaning. As was mentioned above, humidifiers customarily collect a substantial amount of minerals over ⁴⁵a heating season so that in order to remove the minerals, the humidifier must be partially disassembled easily for cleaning. Along with the disassembly, the humidifier must be easily drained. The common method of securing a humidifier onto a duct is to use sheet metal ⁵⁰screws or nuts and bolts. However, these screws or nuts and bolts are difficult to install in a blind location, and it is difficult to attach such a humidifier without assistance. 55

SUMMARY OF THE INVENTION

The present humidifier is one which is particularly adapted for installation for domestic use. It is compact and delivers a large amount of water vapor to an air ₆stream. It is known to use a rotating screen disc to raise ⁰the water from a water tank and place the water into an air stream. It has been observed that the maximum amount of evaporation occurs at the raw edges of a screen. In order to provide an additional amount of raw ₆₅edges in the present device, apertures are formed in the screen discs. The apertures in the screen discs are aligned so that air may flow through the apertures,

3,823,922 which is compact and provides a high volume of water vapor.

It is another object of this invention to provide an improved construction of a humidifier wherein the humidifier may be readily cleaned and maintained. 5

It is still another object of the instant invention to provide a humidifier construction which allows inspection of the interior of the humidifier during operation of the humidifier.

It is a further object of the herein-disclosed invention 10 to provide an improved construction for a humidifier, which humidifier may be easily installed, removed and reinstalled.

It is a still further object of the present invention to provide a humidifier construction which may be readily 15 installed in an existing heating installation.

It is still another object of this invention to provide a humidifier construction which is economical to manufacture.

Other objects and uses of the present invention will 20 become readily apparent to those skilled in the art upon a perusal of the following specification in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS ₂5

FIG. 1 is a perspective view showing a humidifier embodying the present invention suspended from the bottom of an air plenum;

FIG. 2 is an exploded view of the humidifier shown in FIG. 1 in order to show the interior construction of ³⁰the humidifier and the interrelationship of the several parts;

FIG. 3 is a cross-sectional view taken on Line 3—3 of FIG. 1, showing the interrelationship of the plenum, a gasket, a support finger extending through an aper- ³⁵ture in a tank flange, and a wedge;

FIG. 4 is an enlarged perspective view of a finger and wedge construction;

FIG. 5 is an enlarged fragmentary portion of one of the screen discs, showing some of the apertures con- ⁴⁰tained in the discs and showing the raw edge construction;

FIG. 6 is a cross-sectional view through the humidifier shown in FIG. 1, but with the hose removed;

FIG. 7 is a cross-sectional view taken on Line 7—7 ⁴⁵of FIG. 6, showing a disc and a uisc support construction;

FIG. 8 is a cross-sectional view taken on Line 8—8 of FIG. 6, showing the interrelationship of a valve float and an end lock for the discs; ⁵⁰

FIG. 9 is a cross-sectional view taken on Line 9—9 of FIG. 6, showing the interrelationship of the drive shaft and a bearing support of the tank;

FIG. 10 is an exploded view, showing the interrelationship of a screen disc, a screen disc mount, and the ⁵⁵drive shaft, and the mount is partially broken away to show its interior construction;

FIG. 11 is a partial exploded view, showing the humidifier of FIG. 1 mounted on the side of an air plenum; and

FIG. 12 is a perspective view of the humidifier shown in FIG. 1, showing the humidifier of FIG. 1 mounted on a circular duct.

DESCRIPTION OF THE PREFERRED 65 EMBODIMENT

Referring now to the drawings, and especially to FIG.

1, a humidifier generally indicated by numeral 20 is shown mounted on a duct 22. FIG. 2 shows the general construction of the humidifier 20. The humidifier 20 includes a generally rectangular high temperature, medium impact anti-leach polypropylene molded tank 24, a drive housing 26 made of the same material as the tank removably mounted on the tank, and a drive motor 28 mounted in the housing and removably connected to a drive shaft 30. A water carrier 32 is mounted on the drive shaft 30 to rotate in the tank. A tank mount 34 supports the tank on the duct 22. A water drain 36 is mounted on the tank 24 to provide a convenient means for removing the water from the tank. As may be best seen in FIG. 6, a water level control 38 is mounted on the side of the tank for regulating the level of the water in the tank.

The tank 24 is molded in a single piece so that there is no opportunity for water leaks to occur at seams or joints and the tank may be manufactured economically. The tank has a pair of side walls 40, each of which has a window 42 mounted therein to allow inspection of the water carrier 32 and to determine whether the water carrier is operating when the humidifier is mounted on the duct. Formed integral with the side walls 40 is a bearing end wall 44. The bearing end wall includes a shaft support 46 formed integral therein, which has a shaft slot 48 formed therein to receive one end of drive shaft 30. On the end opposite the bearing wall, there is a drive end wall 50 formed integral with the side walls 40. The wall 50 has a drive shaft opening 52 formed therein to receive the drive shaft 30. A pair of mounting apertures 54 is formed in the end wall 50 for receiving a portion of the drive housing. A bottom 56 is formed integral with the side walls and the end walls. The bottom has a slope toward one end, with a drain spout 58 formed integral with the bottom at the lowest part of the bottom. Surrounding the outer periphery of the upper portion of the tank, there is a mounting flange 60. The mounting flange 60 cooperates with the tank mount 34 to hold the tank in position. The mounting flange has a lip 61 formed integral therewith, which lip 61 provides a positioning device for a flexible sponge rubber gasket 62 between the mounting flange and the duct 22. A ridge 63 is formed integral with the flange to improve the seal between the gasket 62 and the flange. The mounting flange has three mounting apertures 64 on each side to receive the tank mount 34. The two side walls have hose supports 65 formed integral with the side walls and the flange 60. The supports 65 each have a T-slot 66 to receive a T-hook 68 connected to the drain 36.

The drive housing 26 consists of two parts, a molded container 70 and a cover 72 removably and slideably mounted on the container. The container 70 includes a front wall 74, which has a pair of mounts 76 formed integral therewith. Each of the mounts includes a pair of resilient prongs 78 which are positionable in their respective apertures 54 to hold the container 70 in position. The front wall 74 also has a pair of mounting grooves 80 formed interiorly therein to receive and to support the drive motor 28. Formed integral with the front wall is a pair of side walls 82. Each of the side walls has a cover slot 84 formed integral therewith to receive slideably the cover 72. A rear wall »6 is formed integral with the side walls 82. The cover 72 is substantially flat and has a stop bead 88 formed integral with one edge thereof. The cover 72 is slideably receiveable

3,823,922 in the slots 84, and the bead 88 provides a stop to stop the cover and to provide a convenient means for grasping the cover for sliding the cover.

The drive motor 28 is a conventional electric motor having a motor housing 90 fixed thereto. The motor 5 housing has a pair of mounting ears 92 extending outwardly therefrom and slideably mountable in the mounting grooves 80 of the front wall. The drive shaft 30 has a drive end 94 which slideably and mateably engages the drive motor to be driven thereby. The other 10 end of the drive shaft 30 is a bearing end 96 which is rotatably mounted in the shaft slot 48 of the shaft support 46. Between the two ends of the drive shaft, there is the carrier portion 96, which supports and drives the water carrier 32. 15

The water carrier 32 includes a plurality of flat screen discs 100 drivingly connected to the drive shaft 30 by mounting blocks 102. Each of the flat screen discs is, in this instance, an 18 mesh aluminum screen wire, although a different size mesh such as 16 mesh 20 may be used instead of an 18 mesh. Each of the screens has an irregular undulating outer edge 104, which edge is raw. Each of the screens has a plurality of circular apertures 106 formed therein. The edges of the circular apertures are also raw. In the center of each of the 25 screens, there is a mounting aperture 108 which receives mounting block 102.

Each mounting block 102 is made of a molded polypropylene material and includes a hollow square base 110 having a hollow square screen support 112 formed ³⁰integral with the base 110. The support 112 has a square shaft aperture 113 formed therein and in registry with a square shaft tube 114 formed integral with the support 112. The tube 114 slideably receives the drive shaft 30. The tube 114 is wholly contained within ³⁵the base 110 and terminates within the base to allow a distance between the end of the tube and the plane of the base to be greater than the thickness of the support 112. The interior of the base 110 defines a square recess 116 which mateably receives an adjacent support ⁴⁰112. Each square screen support 112 is mateably positioned in the respective mounting aperture 108 of the respective screen disc. As may be seen in FIG. 6, the screen support 112 of a mounting block is positioned in an aperture 108 of the respective screen, and the ad- ⁴⁵jacent mounting block is then positioned over the square screen support 112 to sandwich a portion of the screen disc between the blocks and thereby provide support for the screen. An end fastener 118 holds the last mounting block on the shaft at one end. A pair of ⁵support fingers 120 is mounted on the drive shaft in engagement with the last screen to hold the screen upright, and a fastener 122 secures the fingers in place. The support fingers 120 prevent the last screen disc ₅₅from being bent over and into possible engagement ³with the water level control 38. It is evident that the mounting blocks are held between the two fasteners 118 and 122.

The water level control 38 is mounted on side wall ₆₀40. The water level control includes a valve 124 which ° is connected to a conventional source of water, which source is not shown herein. The valve is connected to a stem 126, which is in turn connected to a float 128. The float regulates the level of water in the tank 24 in ₆₅a conventional manner.

The tank mount 34 includes a wire frame 130, which is rectangular in shape and conforms to the shape of the mounting flange 60 of the tank. Six U-shaped spring fingers 132 are mounted on the frame 130. Each of the spring fingers 132 has a fixed arm 134, which is fixed to the frame 130, and a resilient free arm 136. A wedge 138 is positionable in each of the spring fingers 132 to force the flange 60 toward the plenum.

The drain 36 includes a flexible hose 142, which is attached to the drain spout 58 at one end. A transparent tube 144 is attached at one end to the other end of the hose and the other end of the tube is open. The Thook 68 is secured to the open end of the transparent tube 144, and the T-hook is mounted in the T-slot 66 to hold the open end of the tube above the level of the drive shaft opening 52. The level of the water in the tank may be readily observed from a distance by noting the level of water in the transparent tube 144.

The humidifier is mounted on the duct 22 simply and conveniently. An aperture is cut into the sheet metal duct. The aperture is slightly smaller than the aperture defined by the mounting flange 60. Six holes are drilled into the duct, which holes register with the mounting apertures 64 in the flange. The tank mount 34 is then positioned inside the duct, and the spring fingers 132 are pushed through the holes in the duct. In order to mount the tank on the duct, it is necessary only to push the spring fingers 132 into their respective mounting apertures 64. To secure the humidifier, wedges 138 are driven into the space between the fixed and free arms of the respective spring fingers to drive the tank upward, thereby compressing the gasket 62 between the mounting flange 60 and the duct. Since the gasket 62 is made of sponge material, it accommodates any slight irregularities which may exist in the duct. The resilience of the tank also allows the tank to accommodate itself to most irregularities in the duct. The valve 124 is connected to a convenient water supply, and the float 128 acts as a regulator to keep the level of the water below the drive shaft opening 52.

The drive motor 28 is connected to a convenient source of electrical power to turn the drive shaft 30 and thereby rotate the discs 100. As the discs 100 rotate, a portion of the discs rotate through the water in the tank. As the screen discs pass through the water, water adheres to the screen discs and the water is carried on the discs into the air stream which flows in the plenum. The holes 106 in the discs are aligned so that air may flow parallel to the drive shaft through the discs. It is important to note that the discs have a plurality of raw edges, that is, the outer periphery of the discs has a raw edge; and the apertures in the discs also have a raw edge which allows the water to be evaporated from the edges of the discs in a greater quantity since there are numerous raw edges on each disc. The discs have a large length of raw edge on the periphery and a large amount of raw edge in the interior of the disc. However, as the discs rotate, the water does not have a tendency to run off the raw edges of the disc since the outer periphery is a continuous edge; and the apertures in the discs are closed figures so that the water can only run onto the main body of each of the discs. Since the main body of the disc is a continuous screen, the water is held in position on the disc; and the discs operate as a highly efficient water carrier to carry water into the air stream for evaporation. The window 42 allows an operator to observe the operation of the discs to make certain that the discs are rotating properly.

3,823,922

During the operation of the humidifier, an operator may observe the condition of the water and the interior of the tank to determine the amount of mineral buildup in the tank. As the water is evaporated, the minerals in the water are left behind. The operator may note the condition of the water by observing the water in the transparent tube 144. By a periodic draining of the tank, a substantial amount of the minerals which are suspended in the water are removed from the tank to reduce the build-up of minerals. The operator need only detach the T-hook 68 from its slot and lower the transparent tube 144 to allow the water to drain from the tank into a container or a sewer. Once the tank is drained, the hook is replaced in its slot, holding the transparent tube at the proper level. The tank is refilled automatically with clear water. Periodic draining of the tank reduces the build-up of minerals on the tank wall and the screen discs.

In order to give a thorough cleaning of the humidifier, the source of water to the valve 124 is interrupted and the drive motor is disconnected from its source of power. The tank 24 is drained in the manner described above. Once the water is drained out of the tank, the wedges 138 are removed, allowing the tank to be lowered. If necessary, the drive housing may be readily removed from the tank by squeezing together the prongs 78 and pushing the prongs through their respective openings 54. The water carrier is removed from the tank simply by lifting the bearing end 96 out of the slot 48, thus removing the discs from the tank. The minerals which adhere to the tank 24 are removed simply by pushing in the walls and bottom of the tank, which breaks up the minerals and releases them from the tank since the polypropylene provides a soapy or nonadhesive surface. The drive motor 28 is removed from the container 70 and oiled for maintenance.

The humidifier is reassembled simply. Prongs 78 are placed into openings 54 to secure the drive housing to the tank and the motor is replaced in the housing. The water carrier is placed back into the tank. The tank is again placed into engagement with the spring fingers 132 as described above, and the wedges 138 are replaced to remount the humidifier. The transparent tube is then resuspended by the T-hook. The water and electrical connections are re-established, and the humidifier is back in operation. Thus, the humidifier may be quickly and conveniently serviced and put back into operation with a minimum of difficulty.

The humidifier described above may be mounted on a vertical plenum by use of a side adapter 200. Looking now to FIG. 11, which shows a vertical plenum 202, the vertical plenum has an opening 204 cut therein. A chassis 206 is mounted on the plenum. The chassis has a pair of side bars 208, a bottom bar 210, and a top bar 212. A pair of ears 214 is formed integral with the top bar 212 and extends outwardly therefrom. The side adapter 200 includes a housing 216, which has a top wall 218. A pair of side walls 220 is fixed to the top wall, and one of the side walls has an aperture 222. A frame 224 is mounted in engagement with the side walls and the top wall. A mounting frame 226 is connected to the side walls and the frame, and connects the housing to the humidifier 20. The humidifier is mounted on the housing 216 by sliding the flange into a pair of grooves in the side wall 220.

The chassis 206 is attached to the plenum 202 by a plurality of screws, and the housing is simply attached to the chassis by positioning the ears 214 in a pair of apertures 228 in the housing. The frame 224 is positioned between the end of the housing and the aperture 228 so that when the housing is placed into position, the housing is supported by the frame 224, which abuts the chassis 206. The housing is held in position by the weight of the humidifier, which is mounted on the housing. Air flows through the opening 204 into the housing and then out of the housing into the aperture 222 to a cold air return duct through associated duct work, none of which is shown herein. The side adapter 200 may be easily removed from the vertical plenum for cleaning by rotating the side adapter about the ears and lifting the adapter and humidifier.

Another construction for mounting of the humidifier 20 is shown in FIG. 12 wherein the humidifier is mounted on a circular duct 300. The circular duct is slit to form a pair of flaps 302. The flaps are opened to form an aperture in the duct. A pair of end walls 306 is mounted on the ends of the flaps. Corners 308 are positioned between the end walls and the edges of the flaps to form a seal therebetween. A mounting frame 310 is sealingly connected to the flaps and the end walls, and the humidifier 20 is secured to the mounting frame in the manner described above. The operation of the humidifier is the same as that described above.

From the foregoing description, it is readily apparent that the instant humidifier may be easily installed and maintained. It is also important to note that the humidifier is simply constructed so that it is economical to manufacture. Although a specific embodiment of the present humidifier has been described in detail above, it is readily apparent that those skilled in the art may make various modifications and changes without departing from the spirit and scope of the present invention. It is to be expressly understood that the instant invention is limited only by the appended claims.