US1813168A - Refrigerating apparatus - Google Patents

Description

July 7l l1931.

M. KALIscHER l REFRIGERATING APPARATUS Filed Aug. 14. 1929 ATTORNEY Patented Jul'y 7, 1931 iuIL'roN museum, or MANsrIELn, omo, AssIGNoRTo wnsrrNGHoUsE mnc'rmc a l MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA i REFRIGERATING APPARATUS Application led August 14, 1929. Serial No. 385,886.

My invention relates to refrigerating apparatus and specifically to refrigerating apparatus of the type that is provided .with automatic controls.

It is an object of the invention to provide, in such an apparatus, an improved form of expansion or pressure-reducing valve.

A further object is to provide an expansion valve in which the pressure of the refrigerant medium through the evaporator maybe reduced in proportion to a reduction of the evaporator temperature.

More specifically the invention has for its object to provide an expansion valve responsive to the differential between the internal pressure of the evaporator and the ressure existing within a gas lled expansib e chamber located adjacent the evaporator, this latter pressure being in turn responsive to the evaporator temperature.

Other objects and advantages of the invention will be a parent from the following description an -the accompanying drawing, wherein: l y

The single figure illustrates a refrigerating "system embodying the invention, the expanlsion valve being shown on an enlarged scale.

A compressor 1() is drivenv from a motor 11, by means of a belt 12. The compressed refrigerant is liquefied in a condenser 13, and the liquidfrefrigerant is collected in receiver 14. Conduit 15 conducts liquid refrigerant under pressure from the receiver to the pressure reducing valve 16. Liquid ref'ri erant passes through the valve 16 to conduit 1 and thence to the evaporator or heat absorbing chamber 18. The liquid refrigerant in passing through valve 16 has its pressure reduced to such an extent that it vaporizes in evaporator 18, due to the absorption of heat from the surrounding air. The vaporized refrigerant is withdrawn from the evaporator through conduit 19, by the compressor, where it is recomp-ressed for the succeeding cycle. A pressure-operated switch 20, responsive to the temperature of the evaporator 18, may be employed for controlling the' starting and stopping of motor 11.

Referring specifically to the pressure-reducing valve 16, which comprises the present inventiomthere is shown a casing 21 having a central elongated tubular portion 22 provided at each of its ends withan enlarged. portion or chamber 23 and 24. The cham-U ber 24 contains a seat 25, with which oooperates the valve member 26. The valve is provided with a stem 28, and carries a collar 27. A light coil spring 36 encircles the stemv 28 and is retained between the collar 27 and a recessed member 29, which ma be screw-threaded in to the chamber 24 an adjustable from. outside the chamber in order to regulate the tensionr of the spring.- The spring normally tends to seat valve 26.

Chamber 23 has a portion of its surface disposed in intimate thermal contact with the evaporator. `An ex ansible element or sylphon bellows 30 is isposed within chamber 33 and is supported from that portion of the chamber which is in thermal contact with the evaporator.

The movable end ofbellows 30 is closed by a head 31 which has rigidly attached thereto one end of a rod 32. The rod lextends through the elongated tubular ortion 22 of the valve casing, and 'is slidab y supported v with a volatile gas which, under predeter-l mined temperature conditions, will build up suiilcient pressure to expand the bellows and thereby move rod 32 to the right in the figure. The movement of the rod in this direction will cause it to bear against the adj acentarm of the bell-crank lever 34, and thereby rotate this lever in a clockwise direction about its pivot 35. The other arm of the bell. crank' lspring 36 and will thereupon compress the permit the valve to unseat.

In the operation o f the device, assuming the evaporator to .be relatively warm, the volatile gas'in the expansible member 30 will the most eicie'nt operetion oi the com exert sutiicient pressure to move rod 32 and bell-crank lever 34 and thereby unseat vaive 26. This Will admit a quantity or? iiquid refrigerant to the evaporator 18 at a reduced pressure. The refrigerant then expands, due to the absorption of heat dfrom the air surrounding the evaporator, and builds up a back pressure which acts against head 3l of expansible element 30, and thereby opposes the pressure exerted Within this eiement by the gas contained therein. When the back pressure in the evaporator and consequently in the chamber 23 isequal to that Within the bellows, the spring 36 seats the valve 26..

'An excess of pressure Within the beiiows,

over the combined back pressure and pressure of the spring, Wiil unseat the valve and permit more refrigerant to enter the evaporator. Since the pressure Within beliovvs 30 is directly dependent on the temperature of evaporator 18, it Wiii be apparent that the valve is controlled by both the evaporator temperature and the pressure Within the evaporator, as distinguished from the con ventional expansion vaive between the back pressure and atmospheric pressure acting on opposite sides of a diaphragm or oeliows, assisted generally by a spring.

The tubuiar portion 22 is made oi considerable length and' provided with iins 37, in order that the temperature ont the valve chamber may not iniiuence the errpansible element 30, thereby permitting the to be controlled entireiy by the evaporator tern perature. l

It will be apparent that my invention provides an expansion vaive which is decidedly sensitive and Will maintain a pressure in the evaporator which is proportionai to the evaporator temperature, thereby ensuring pressor. v

While have shown a single embodiment of the invention, it vvili be epparent that other forms might be adopted, aii coming within the scope of the appended' ciainis.

I claim as my invention z 1. In a refrigerating apparatus, an evaporator, an expansion vaive for controlling the flow of refrigerant medium through said evaporator, said valve eoinprising,` a sealed casing having enlarged end portions and an intermediate tubular portion, one ofthe enlarged end portions being adjacent the evaporator and in thermai contact therewith, a gas-filled expansible member in said adjacent portion, a valve and valve seat in the opposite end portion, and operative connections between said expansible member and said valve, said connections passing through the tubular portion.

2. An expansion .valve comprising a relatively long tubular portion having enlarged recesses at each of its ends, the Whole comprising a sealed casing, an expansible memc Lerares

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