US2243307A - Evaporator - Google Patents

Description

y 1941- J. L. CAMPBELL 2,243,307

' EVAPORATOR Original Filed Sept. 20, 1929 of ice trays or other receptacles.

- Fig. 1, may be formed in the evaporator. An overflow spout 25 communi- Patented May 27, 1941 I EVAPORATOR Jackson Lee Campbell, Wichita, Kans., assignor to Sears, Roebuck and 00., Chicago, Ill., a corporation of New York Original application Sep N0.394,011.' Divided 6, 1939, Serial No.

tember 20, 1929, Serial and this application June Claims. ((31.62-126) This application is a division of my co-pending application Serial No. 394,011, filed September 20, 1929, now matured into Patent No. 2,210,898.

My invention relates to refrigeration apparatus and has to do more particularly with an evaporator designed especially for use in a continuous absorption system, although, as will be readily understood by those skilled in the art, my invention is not limited to such a system of refrigeration.

A particular object oi my invention is to provide an evaporator which will efliciently eifect heat transfer from a liquefied refrigerant in the presence of an inert gas.

Another object is to provide a device of the type referred to which will be simple in construction, easy to fabricate, and, in 'generaLentirely satisfactory for the purposes desired.

Referring now to the drawing forming a part of this specification and illustrating a preferred embodiment of my invention:

Fig. 1 is a vertical sectional view of an. evapo-i rator embodying my invention, ated parts being shown fragmentarily, and

Fig. 2 is a similar view taken substantially 'along the line 2--2 of Fig. i.

Numeral i0 represents generally a refrigerator cabinet having a food compartment i2 in which is disposed an evaporator, indicated generally by the numeral l5, embodying my invention.

The evaporator'comprises a substantially rectangular casing l6 of metal or other suitable material of good heat conductivity, heat exchange fins l8 extending around the to bottom and side walls thereof. The' evaporator may have an open ended compartment 20 for the reception A conduit 2 I leading from a condenser or other suitable source of liquid refrigerant extends through the top wall of the evaporator and discharges into a well 23. This well,'as shown in part by a side wall of cates with the upper portion of well 23 and discharges ontothe uppermost .of a series ofbailie plates 21 arranged in an evaporating chamber 28 laterally adjacent the compartment. These baflie plates'are alternately inclined in opposite directions and are provided with outlet openings 30 adjacent their lower ends, so that liquid which is discharged from the well 23 onto the uppermost bafiie plate 21 flows downwardly," then through the orifice 30, and then similarly from one baflie plate to another until it reaches the municating with the bottom of the evaporating chamber 28 is a discharge conduit 32!.

A conduit 35, concentric with the conduit 32 and larger than the same, communicates with a substantially as follows:

Liquid refrigerant is introduced, as from a condenser (not shown), through conduit 2| into the well 23 while hydrogen or other inert gas is introduced through conduit 35 into the flue 31 and thence into the evaporating chamber 28, where it mingles with the liquid refrigerant which is poured into the evaporating chamber through overflow spout 25. The reservoir 23 provides a substantially constant supply of refrigerant to the evaporator plates and tends to prevent certain associflooding thereof. Theinert gas, admixed with the liquid refrigerant. flows successively down the plates 21 until it reaches the bottonLof the chamber, evaporation taking place in the course of the flow until the mixture of inert gasand refrigerant gases is discharged through the conduit 32, whence it passes into a suitable absorber 'where the refrigerant will be absorbed and the.

inert gas will be returned to the evaporator via conduit 35.

The-inert gas operates within the evaporator according to Daltons law of partial pressures, which is now well understood. According to this law, the partial pressure of any gas in a mixture hydrogen or other inert gas,fthere will immediately be a tendency for the liquid to evaporate and thus exert its own vapor pressure, keeping the total pressure constant. Thus, the presence of the inert gas enhances the evaporation of the refrigerant. Since the bottom 01' the evaporating bottom of the ,evaporating chamber 28. Comchamber is open to discharge, the maximum vapor pressure of the refrigerant will never be reached and hence a condition of equilibrium can neverbe obtained and the evaporation will continue at a maximum rate- Evaporation is also enhanced by the circuitous route which must he traveled by the liquid refrigerant in passing from the top to the bottom of the evaporatingchamber. There is thus established a continuous circulation through the evaporator of inert gas admixed with refrigerant, the combined gasesbeing discharged at'the bottom through the conduit 32.

Various modifications and variations coming within the spirit of my invention may suggest themselves to those skilled in the art, and hence I do not wish to be restricted to the specific form shown or uses mentioned, except to the extent indicated in the appended claims, which are to be interpreted as broadly as the state of i tuting the sole outlet therefrom, said gas conducting means and said discharge means being disposed in heat exchangerelation.

2. A. combination as defined in claim 1,- wherein the means for conducting an inert gas to the top of the chamber consists of a flue having one wall in common with said well and a wall in common with said evaporating chamber.

3. In combination, in a refrigeration unit, a substantially rectangular casing comprising a substantially rectangular evaporating chamber having a plurality of vertically spaced apertured plates, alternate plates being oppositely tilted from horizontal position to promote the flow and evaporation of refrigerant, a substantially rectangular cooling chamber in heat exchange relation to said evaporating chamber, means for feeding refrigerant liquid and means for feeding inert gas to the uppermost of said plates, and means for discharging mixed refrigerant and inert gas from said refrigerant chamber. Q

4. In combination, in a refrigeration unit, a substantially rectangular casing comprising a substantially rectangular evaporating chamber having a plurality of vertically spaced a'pertured .plates, alternate plates being oppositely tilted from horizontal position to promote the flow and evaporation of refrigerant, a substantially rectangular cooling chamber in heat exchange relation to said evaporating chamber, a refrigerant well formed. integrally with said evaporating chamber, overflow means for conducting liquid refrigerant from said well to the uppermost of said plates, a fine for inert gas disposed between said well and the refrigerant chamber and discharging to the space above the uppermost of said plates, and means for discharging mixed refrigerant and inert gas from the lower portion of said refrigerant chamber.

5. In combination, in a refrigeration unit, a

substantially rectangular casing comprising a.

substantially rectangular evaporating chamber having a plurality of vertically spaced apertured plates, alternate plates being oppositely tilted from horizontal position to promote the flow and evaporation of'refrigerant, a substantially rectangular cooling chamber in heat exchange relation to said evaporating chamber, arefrigerant wellformed integrally with said evaporating chamber, overflow means for conducting liquid refrigerant from said well to the uppermost of said plates, a flue for inert gas disposed between said well and the refrigerant chamber and discharging to the space above the uppermost of said plates, means for discharging mixed refrigerant and inert gas from the lower portion of said refrigerant ch'amber,-said discharge means constituting the sole outlet from said evaporatingchamber, and means in heat exchange relation with said discharge means for conducting inert gas to said flue.

JACKSON LEE CALIPBELL.

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