US2682758A - Dehumidifying apparatus - Google Patents

Description

y 1954 A. R. HARRIS DEHUMIDIFYING APPARATUS 2 Sheets-Sheet 1 Filed May 13, 1952 Inz/en for: w'z/l flarrzls July 6, 1954 A. R. HARRIS DEHUMIDIFYING APPARATUS Filed May 15, 1952 2 Sheets-Sheet 2 Patented July 6, 1954 UNITED STATES DEHUMIDIFYING APPARATUS Arve'l E. Harris, Evansville, Ind., assignor to International Harvester Company, a corporation of New Jersey Application May 13, 1952, Serial No. 287,566

4 Claims.

This invention relates generally to dehumidifying apparatus and more particularly to a refrigeration system adapted to lower the relative humidity of air within an enclosure.

The invention comprises an apparatus havin a refrigerant evaporator and a refrigerant condenser arranged in series with means for passing air to be dehumidified first into contact with said evaporator and then into contact with said condenser. As the warm moist air passes into contact with the evaporator, it will be cooled to its dew point and moisture will be condensed therefrom onto the surfaces of the evaporator from which it may be drained by suitable means. The air is then passed over the condenser where it picks up heat from the hot refrigerant gases and is heated to its original temperature. In commercial practice .it has been found that apparatus of this type does not operate as efiiciently as desired in that the quantity of water removed from the air is sometimes relatively small. It has been determined that the reason for the small amount of condensation is the fact that the evaporator must first lower the temperature of the air from room temperatures to dew point temperatures before moisture will condense therefrom. This means that a large portion of the capacity of the evaporator will be used in removing sensible heat from the air before condensation begins. The present invention is concerned with overcoming this difficulty so that the refrigeration system will remove a larger quantity of moisture.

One object of the present invention is to provide a dehumidifier with a refrigeration system having the evaporator and condenser arranged in series with means for circulating air to be conditioned into contact with said evaporator first, and then into contact with said condenser.

Another object of the invention is to provide means for-collecting and removing the water that condenses on the surfaces of said evaporator.

Another object of the invention is to provide a heat exchange element for pre-cooling the air before it contacts said evaporator in order that a substantial portion of the sensible heat of the air will be removed before the air contacts the evaporator. 1

Another object of the invention is to arrange the heat exchange-element between the evaporator and condenser so that incoming air is passed into heat exchange relation with air which has been cooled by said evaporator and is being forwarded to said condenser.

Another object of the invention is to provide means for bypassing room air around said evaporator directly into contact with said condenser.

Another object of the invention is to provide a compact dehumidifying unit which is light in weight and can be easily moved about by one person.

. 5 by mounts 23.

Further objects and advantages of the invention will become apparent as the following description proceeds, and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of the invention, reference may be had to the accompanying drawings in which:

Fig. 1 is a vertical sectional View of a dehumidifying unit embodying the features of the invention.

Fig. '2 is a cross-sectional view of the unit taken along line 2 2 of Fig. 1.

Fig. 3 is a vertical sectional view of a modified form of the invention.

Fig. 4 is a cross-sectional view of the unit taken along line i-i of Fig. 3.

Fig. 5 is a cross-sectional View of the unit taken along line 5-5 of Fig. 3.

Referring to Figs. 1 and 2 of the drawings for a detailed description of the invention, a dehumidifying unit is designated generally by reference numeral I0. The unit It comprises an outer metallic casing ll having a top wall l2, side walls I3 and It, and end walls 15 and I t. Positioned within the casing l l is a refrigeration system comprising a hermetically sealed motors compressor unit ll, an evaporator l8, and con denser l9. The refrigeration system is charged with a suitable refrigerant which is compressed by the motor-compressor unit H during operation thereof and then conveyed by conduit 28 to condenser [9. ,As the refrigerant flows through condenser [9, it is cooled and condensed and then flows therefrom through a capillary restrictor tube 2| to evaporator is. After being heated to a vapor during its passage through the evaporator iii, the refrigerant is returned to the motorcompressor unit ll through conduit 22 to be recompressed and'forwarded through the system again.

In the modification shown in Figs. 1 and 2, the motor-compressor unit I1 is secured to end wall Condenser I9 is secured to top wall [2 by bolts '24. Secured to top wall I2 by brackets 25 and bolts 26 is an electric motor 21 having an armature shaft 28 on which a propeller type fan 29 is mounted adjacent to condenser l9. End wall 15 is provided with an opening 36 therethrough adjacent to motor 21 with vanes 31 secured therein for the purpose of directing air currents therethrough. A parti-v tion 54 is positioned below the condenser is and the motor 21. A shroud 32 is secured to condenser and is arranged to enclose fan 29 so that when motor 21 is running, the fan 22? Will pull air through the condenser l9 and force it through the opening 39. The evaporator 18. is

spaced from the condenser I9 and attached to top wall I2 by brackets 33 and bolts 34. Positioned below evaporator I8 is a receptacle 35 which may be a common household bucket. End wall I6 is provided with a rectangular shaped opening 36 through which the receptacle 35 may be inserted and removed.

Positioned between condenser l9 and evaporator I8 is a heat exchange unit 31 comprising an outer horizontal duct 38 having side walls 39 and 45 and inclined top wall 4I and bottom wall 42. One end of the duct 38 is secured to the edges of the condenser [9 in sealed relationship whereas the other end is secured to the evaporator I8 in sealed relationship so that air being circulated by fan 29 will pass first through said evaporator and then through said condenser. Bottom wall 42 of duct 38 is provided with a small opening 43 adjacent condenser l9 with vanes 44 secured therein for the purpose of di recting streams of air passing therethrough.

Bottom wall 42 and top wall 38 are provided with spaced apart slots in which the ends of upright ducts 45 are secured. The upright ducts 45 are spaced between side walls 39 and and are secured thereto by straps 46. As seen in Fig. 2, the straps have semi-circular shaped grooves therein which receive the curved walls of the ducts 45. The straps 46 may be arranged to clamp the ducts therebetween or suitable means, such as spot welding, may be employed to permanently attach the ducts to the straps.

A curved duct 41' having top wall 48, end wall 49, bottom wall 59, and side walls 5| and 52 is positioned with bottom wall secured to evaporator I8 and an oifset edge 53 of top wall 48 secured to top wall 4| of horizontal duct 31. The side walls 5| and 52 of the curved duct 4? engage the horizontal duct 48 and the sides of evaporator I8 and seal thereagainst so that air being drawn through evaporator I8 by fan 29 will be pulled from upright ducts 45 through curved duct 41 The operation of the motor-compressor unit I! and electric motor 21 may be controlled automatically or manually. When dehumidification of air is needed, both the motor 27 and motorcompressor unit I? are energized from a suitable electric supply. With the motor-compressor un1t II operating, the refrigerant will be circulated through the refrigeration system as explained heretofore whereby the surfaces of the condenser I9 will be maintained at a high temperature and the surfaces of the evaporator I8 will be maintained at a low temperature. Air to be dehumidified is pulled in opening 36 by fan 29, circulated upwardly through upright ducts 45, through curved duct 4?, over evaporator I8, through horizontal duct 38, over condenser I9 and then expelled from the casing I I through opening 39. As the air passes over the cold surfaces of the evaporator 18, it will be cooled below its dew point and the water vapor carried thereby will be condensed onto the surfaces of the evaporator, from which it will drain into receptacle 35. The air then passes through duct 38 over the hot surfaces of the condenser I9 where it will be reheated to substantially the same temperature as when it entered the casing I I.

As mentioned heretofore, the purpose of the heat exchange unit 31 is to pre-cool the air before it contacts the evaporator l8 so that most of the sensible heat is removed thereby. The chilled air which is flowing between the evap: orator I8 and the condenser I9 wipes over the outer surfaces of the upright ducts 45. Since the air being pulled upwardly through the upright ducts 45 is at a higher temperature, there will be a transfer of heat between the hot air flowing through th upright ducts 45 and the cold air flowing through horizontal duct 38. This transfer of heat cools the air within u right ducts 45 to a temperature approaching the dew point of the air so that the greater portion of the capacity of the evaporator I8 is used in condensing water from the air, or, in other words, removing latent heat from the air. The opening 43 in the bottom wall 42 of duct 38 allows a limited volume of air from opening 36 to flow directly over the condenser I9, and vanes 44 may be made adjustable in order that the volume of air may be controlled. The air flowing through opening 43 aids in cooling the condenser, and since this will reduce the volume of air flowing through evaporator I8, a greater amount of heat will be removed from this air by the evaporator.

Figs. 3, 4 and 5 illustrate a modification of the invention in which the parts thereof are arranged in a different manner. The outer casing 54 of the unit is positioned upon a floor 55 and is provided with a top wall 55, end Walls 5'! and 55, and side walls 59 and 55. The interior of the casing 54 is divided into an upper compartment 6i and a lower compartment 62 by partition 53. The condenser 94 is located in the upper compartment EI and is secured to partitions 53 by bolts 55. The evaporator 55 is located in lower compartment 52 and is fastened to partition 53 by bolts 57. The motor-compressor unit 58 is secured to partition 63 by resilient mounts 59 with the outlet thereof connected to condenser 64 by conduit iii and the inlet thereof connected to the evaporator 56 by conduit ll. A capillary tube 72 connects the condenser 64 and evaporator and the refrigeration system operates in the same manner explained above with reference to Figs. 1 and 2. The compressed refrigerant flows from compressor 58 through conduit Til, condenser 54, capillary tube f2, evaporator 55, conduit H and back to compressor 53 to complete the cycle.

End wall 58 is provided with an intermediate opening 73 and a top opening '54 in which are secured vanes 15 and it respectively. Evaporator 65 is connected to intermediate opening 73 by a heat exchange element l? comprising a horizontal duct it having a bottom wall 19 and side walls 35 and BI. Duct is secured to partition 63 by brackets 82 with the side Walls and BI contacting said partition. Bottom wall E9 and partition 63 are provided with openings 99 there through into which the ends of upright ducts 83 are inserted. The upright ducts 83 are held in place by straps 54 having the ends thereof secured to side walls 8?} and 8 I. An electric motor 85 is positioned in upper compartment GI and is secured to partition 63 by brackets 86 and bolts 87. A fan 88 is mounted upon the armature shaft 89 of motor 85 adjacent condenser 64 and a shroud 99 surrounds the fan 88 and is secured to condenser '54. End wall 5'! is provided With an outlet opening 9| adjacent motor 85 with vanes 92 secured therein, A receptacle 93 is positioned upon floor 55 below evaporator 66 so that it will collect any water which drains from the surfaces of the evaporator 66.

When air is to be dehumidified by the unit, the motor 85 and motor-compressor unit 58 are energized simultaneously so that the refrigeration system Will Operate and air will be circulated by fan 88. The air is pulled into the casing 54 through opening 13 and circulated through horizontal duct 19 around upright ducts 83 and through evaporator 66. The air then flows downwardly around receptacle 93 and up through'upright ducts 83, around the motor-compressor unit 98, through condenser 64, and out opening 9|. Water from the air will condense on the cold surfaces of the evaporator 66 and drain into receptacle 93 which may be removed for emptying by raising the unit 54 from the floor 55. The air will be reheated to its incoming temperature by the hot surfaces of the condenser 64. The heat exchange unit H will pre-cool the air before it strikes the surfaces of the evaporator 66 by the transfer of heat to the cold air flowing upwardly through upright ducts 83 from evaporator '96 to condenser 64 as explained more thoroughly in the description of Figs. 1 and 2. Room air will flow directly into contact with condenser 64 through top opening 14 so that the temperature of the evaporator will be held at a lower value whereby a larger quantity of water will be condensed from the air.

As is readily apparent from the preceding description, the present invention provides a dehumidifier which will operate to remove a large quantity of water from air having a high relative humidity. The heat exchange unit placed between the condenser and evaporator provides a means of pre-cooling the incoming air before it contacts the evaporator and allows a greater portion of the capacity of the evaporator to be used for removing latent heat from the air. By providing the bypass opening for passing air directly into contact with the condenser, a smaller volume of air will flow over the surfaces of the evaporator whereby the temperature of the evaporator will be maintained at a lower value. The components of the dehumidifier are arranged in a compact manner and the unit is light in weight so that it can be easily lifted and carried by one person. The receptacle for collecting condensate is of such size that it wil1 hold a large quantity of water and is arranged in a manner which permits quick remova1 for emptying,

It will, of course, be understood that various changes in details of construction and arrangement of parts may be made by those skilled in the art without departing from the spirit of the invention as set forth in the appended claims.

What is claimed is:

1. In apparatus for dehumidifying the air within an enclosure, a casing, a horizontally disposed wall mounted within said casing dividing said casing into upper and lower compartments, a refrigerant condenser and a refrigerant evaporator having inlet and outlet sides for the passage of air therethrough, said refrigerant evaporator mounted to said wall within said lower compartment, said casing having an inlet opening formed through one vertical wall thereof and positioned adjacent said lower compartment, said casing having an outlet opening formed through another vertical wall thereof adjacent said upper compartment, an air-to-air heat exchanger having first and second ducts therethrough in thermal contact, said air-to-air heat exchanger mounted to said Wall within said lower compartment, said first duct of said air-to-air heat exchanger connected to said inlet opening and said inlet side of said evaporator, said second duct connected between said upper and lower compartments through an opening provided in said wall, said refrigerant condenser mounted to said wall within and substantially across said upper compartment between said outlet opening and said second duct of said air-to-air heat exchanger, a

motor-compressor unit for the operation of said refrigerant evaporator and said refrigerant condenser mounted to said wall within said upper compartment substantiallyover a portion of said second duct, fan means mounted to said wall within said upper compartment between said outlet opening and said outlet side of said refrigerant condenser, said fan means operable to draw air from said enclosure into and through said inlet opening, into and through said first duct of said air-to-air heat exchanger, into said inlet side of said refrigerant evaporator, through said refrigerant evaporator, from the outlet side of said refrigerant evaporator through said lower compartment, into and through said second duct of said air-to-air heat exchanger, into said upper compartment and over the surfaces of said motorcompressor unit, into said inlet side of said condenser, through said refrigerant condenser, from the outlet side of said refrigerant condenser through the remainder of said upper compartment and through and out of said outlet opening, whereby said air is precooled by the transfer of heat to said first duct, whereby the air is cooled to the dew point temperature thereof and water is condensed upon the surfaces of said evaporator, whereby the air is then heated as it passes through said second duct of said air-to-air heat exchanger, whereby said motor-compressor unit then transfers heat to said air and whereby said air is further heated by passage through said refrigerant condenser and projected into said enclosure, when said motor compressor unit is operating;

2. In apparatus for dehumidifying the air within an enclosure as claimed in claim 1, a bypass opening formed through said one Vertical wall of said casing and positioned adjacent said upper compartment, whereby air from said enclosure is drawn through said bypass opening over the surfaces of said motor-compressor unit, through said refrigerant condenser, and out of said outlet opening when said fan means are operating.

3. In an apparatus for dehumidifying the air within an enclosure as claimed in claim 1, a condensate receptacle removably mounted within said lower compartment below said refrigerant evaporator, whereby any Water condensed upon the surfaces of said refrigerant evaporator is collected within said condensate receptacle.

4. In apparatus for dehumidifyin-g the air within an enclosure as claimed in claim 3, said casing being provided with a receptacle opening on the underside thereof, said receptacle opening having a size suflicient to admit said condensate receptacle therethrough, whereby said condensate receptacle is removable and replaceable into said lower compartment through said receptacle opening.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,093,968 Kettering Sept. 21, 1937 2,196,473 Ploeger Apr. 9, 1940 2,200,118 Miller May '7, 1940 2,237,332 Bretzlaff Apr. 8, 1941 2,369,511 Winkler Feb. 13, 1945 2,438,120 Freygang Mar. 23, 1948 2,522,434 Ringquist Sept. 12, 1950

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