US 2296997 A
Description (OCR text may contain errors)
Sept. 29, 1942. M. F. KNOY 2,296,997
CONDENSATE DISPOSAL MEANS Filed Aug. 3, 1940 HA RRAS/ K/ECH? F05 7-51? 6 HARE/6 at -M Arromvays Patented Sept. 29, 1942 UNITED STATES PATENT OFFICE 2,296,997 CONDENS ATE DISPOSAL MEANS Marion F. Knoy, Long Beach, Calif. Application August 3, 1940, Serial N0. 350,534
My invention relates to refrigerating systems with special reference to air conditioning apparatus, and is directed to an improved means for disposing of water derived from the air in the operation of such apparatus.
The cooling of air by an air conditioning apparatus of the type under consideration is accom-v plished 'by passing the air in a stream over the surfaces of a cold element or evaporating coil maintained at substantially under the temperature of the air. In air-cooling practice, a temperature diflerential of 20 to 30 F. is sought and the temperature of the cold element is often below the dew point of the air for extended periods of time, the result being the continuous condensation of water from the air upon the surfaces of the cold element. To avoid damage toparts of the cooling apparatus or to furnishings adjacent the cooling apparatus some drip-catching or drainage expedient is required. Conditions commonly prevalent in hot weather cause rapid condensation and in the absence of adequate disposal means the water soon accumulates to a formidable quantity.
In many systems drainage to a sewer is not feasible or if feasible would be disproportionately expensive. In such installations it is necessary either to provide drainage receptacles to be emptied manually from time to time or to convey the condensates to the hot side of the refrigerating system for dissipation into the air that isseparately circulated on that side of the system. My invention is directed to this latter disposal arrangement.
Experience in this .field demonstrates that simple exposure of the superfluous water to the normal air flow on the hot side of the refrigerating system cannot be relied upon for disposal; the maximum rate of evaporation is never adequate for peak water loads.
Various expedients have been suggested in the prior art. One suggestion is to employ only the usual rate of air flow required for the refrigerating system and to restrict that air flow locally for high velocity in intimate contact with the water to be dissipated,
the intent being to cause the air stream to enblowers or fans far above the requirements for cooling the refrigerant on'the. hot side of the -achieve suflicient velocity to sweep the water out of the disposal receptacle.
The general object of my invention is to provide means to dispose of water condensed from the air on the cooling side of a refrigerating system. More specifically, it is my object to provide for adequate water disposal by evaporation alone and to do so by structural means requiring only normal air flow and only normal power consumption. Another object of my invention is to facilitate the cooling of refrigerant on the hot side of a refrigerating cycle thereby to raise the efficiency of the refrigerating apparatus. A still further object is to provide such a system in which it is not necessary to place the cold element of the refrigerating system higher than the refrigerant condenser.
Other objects and advantages of my invention will be apparent in my detailed description below, taken with the accompanying drawing.
Broadly described, my invention is based on the concept of transferring heat directly to the accumulated body of surplus water from the hot refrigerant on the compression side of the refrigeration system to attain a sufficiently high rate of vaporization to meet peak conditions. While an air'stream across the body of water simplifies the problem, it is apparent that my method may be applied to any coolin system in the operation of which refrigerant". compressed, whether or not an air stream is available on the hot side of the system.
In the drawing which is to be considered as illustrative only:
Fig. 1 is a diagrammatic representation of an air-cooling apparatus incorporating my invention;
- Fig. 2 is a transverse section taken as indicated by the line 2-2 of Fig. 1 showing the disposal receptacle in plan; and
Fig. 3 is a fragmentary view similar to Fig. 1 to illustrate a modification of my invention.
Fig. 1 is a diagrammatic layout of a typical aircooling cabinet that is divided by an air-tight wall i0 into a cooling compartment l I on the cold side of the refrigerating cycle and a compartment I! on the hot side of the cycle. Refrigerant from a condenser I5 in the compartment I2 is conveyed by a pipe It to an expansion valve I! in the compartment H and is released into a cold element or evaporating coil 20. A compressor 2| in the compartment 12 driven by a motor 22 draws the gaseous refrigerant from the evaporating coil 20 through a suction pipe 23. Upon being comcycle, the additional air flow being used to pressed in the compressor 2| and raised in'temperature because of the heat of compression, the refrigerant is conducted from the compressor to the condenser l5 through a pipe 25. v
In accord with conventional practice a blower 26 in an air duct 21 driven by a motor 28 draws outdoor air into the compartment l2 over the surfaces of the various elements in the compartment [2; and discharges the air outdoors through the airduct. The current of outdoor air through the compartment l2 sweeps and eddies over the various surfaces to pick up heat from the condenser l5, the compressor 2|, the. pipe 25, and the two motors 22 and 28.
a liquid formed in the coil is immediately carried Indoor air moving ina current through the.
cooling compartment l I passes over the evaporating coil 20 and in doing so yields moisture to the surfaces of the evaporating coil. The moisture forms droplets which are eventually caught in a drip pan 30 under the evaporating coil and water that tends to accumulate in the drip pan is conducted by a drainage pipe 3| through the wall i0 into a disposal receptacle 32 in the bottom of the compartment l2.
My invention as embodied here consists, first, in immersing a portion of the pipe 25 in the body of superfluous water 35 in the disposal receptacle 32 and, second, in directing the air stream in the compartment l2 over the surf-ace .of the body'of superfluous water. As indicated in Fig. 2 the pipe 25, which contains superheated refrigerant gas, may be formed into a coil 36 in the disposal receptacle 32, the pipe being coiled to whatever length is necessary to achieve the required rate of heat transfer to the body of water 35.
As for the air stream through the compartment I2, various expedients may be employed to bring the air into intimate contact with the surface of the body of water 35. In the present arrangement, it will be noted that the inlet 31 of the air duct 21 is close to the upper edge of the disposal receptacle 32 and that flow of air along the body of water 35 in the disposal receptacle is further favored by a bafile 38 extending from the inlet 31 over the disposal receptacle. The air stream is heated before it reaches the disposal receptacle by contact with the condenser i5 and subsequent contact with the hotter surfaces of the pipe 25. The heated air stream attains a relatively high velocity at the disposal receptacle not only because the receptacle is relatively close to the inlet 31 but also because of the baiiie 38.
In the disposal receptacle 32 the refrigerant in the pipe 25 loses part, if not all. of its superheat to the body of water 35. Under some operating conditions this superheat, together with the rapid flow of the heated air above the receptacle, is suflicient to keep the water in the receptacle down to insignificant volume. At higher rates of water condensation the residual body of water 35 in the disposal receptacle may increase to substantial volume but the increase will be limited because, in the first place, the higher the water level'the larger the area of the pipe '25 in contact with the water and, in the second place, the length of the pipe 25 that is coiled in the disposal receptacle is designedly sufllcient to cause a part of the refrigerant to liquefy whenever any substan ial body of water is present to cool the coil. In liquefying, the refrigerant releases its'latent heat of vaporization to expedite evaporation of the water in the disfrom the condenser I5.
over to the condenser 15 by the high velocity gaseous stream of refrigerant.
Since the pipe 25 in passing through the body of water .35 participates in the necessary step of removing the superheat and the heat of vaporization from the compressed refrigerant and thus takes some of the load of the condenser, it causes reduction in the condenser pressure and thus not only solves the problem of water disposal but also increases the efficiency and capacity of the apparatus as a whole.
From an inspection of Fig. 1 it will be apparent that it is not necessary that the evaporating coil 20 be higher than the condenser l5 since the only consideration in locating the evaporating coil is to provide drainage to the disposal recep tacle 32 and the disposal receptacle is divorced In arrangements suggested heretofore for disposing of superfluous water, the disposal receptacle is immediately under or immediately adjacent the condenser in the refrigerating system so that adequate drainage from the drip pan under the evaporating coil may be achieved only by placing the evaporating coil at a level substantially above the level of the condenser. My apparatus may be readily adapted to any situation in which it is necessary or desirable to place the condenser at some level substantiall above the evaporating coil.
The arrangement in Fig. 3 is in most respects identical with the arrangement in Fig. 1 as indicated by the use of like numbers to indicate like elements. The distinction in the arrangement of Fig. 3 over the arrangement of Fig. 1 is in the substitution of a relatively deep disposal receptacle 4D for the relatively shallow disposal receptacle 32 and in the substitution of a relatively small auxiliary condenser 4| for the coil 36. The auxiliary condenser M assures the availability of sufficient heat of vaporization from the refrigerant to vaporize the body of water 52 without danger of overflow.
The preferred forms and practices of my invention described in detail herein will suggest to those skilled in the art various changes and substitutions that may be made without depart ing from my underlying concept; I reserve the right toall such changes and substitutions that properly come within the scope of my appended claims.
I claim as my invention:
1. In an air-cooling apparatus having a refrigerating cycle including a compressor, a condenser, and an evaporator, the combination there-' with of disposal means to vaporize water condensed on the outer surface of the evaporator, said disposal means comprising: walls forming an air course through the apparatus cut off from said evaporator; power means to drive fresh air through said air course; a disposal receptacle to retain a body of water drained from the surface of said evaporator; and a fluid-passage means included in said refrigerating cycle in the hottest zone thereof between the output side of the compressor and the input side of the condenser, said fluid-passage means having an exposed portion in said air course and a portion submerged in said body of water, said condenser being in said air course. said exposed portion of said fluid-passage means being in said air course downstream from said condenser, whereby air flowing through said air course is initially heated by the warm surface of said condenser and is then heated further by the exposed portion of said fluid-passage means to'lower the relative humidity of the air before the air reaches the water in the receptacle, said air course being locally restricted in cross section at said receptacle to accelerate the air flow across the surface of said body of water.
2. In an air-cooling apparatus having a refrigerating cycle including a compressor, a condenser, and an evaporator, the combination therewith of disposal means to vaporize water condensed on theouter surface of the evaporator, said disposal means comprising: walls forming an air course through the apparatus sealed off from said evaporator, said condenser and said compressor beingin said air course; power means to drive fresh air through said air course; a disposal receptacle to retain a body of water drained. from the surface of said evaporator, said receptacle being in said air course downstream from said condenser, there being a substantial extent of the air course between the condenser and the receptacle; and a fluid-passage means included in said refrigerating cycle in the hottest zone thereof between the output side of the compressor and the input side of the condenser, said fluidpassage means including a first portion from thecompressor to the receptacle, a second continuing portion submerged in the body of water in the receptacle, and a third continuing portion ex- MARION F. KNOY.