US1739639A - Coating and heat treating - Google Patents

Description

Dec. 17, 1929. J. G. KING 1,739,639

REFHIGERATING APPARATUS Filed Dec, 1, 1924 Patented Dec. 17, 1929 UNITED STATES PATENT OFFICE JESSE G. KING, OI DAYTON, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO FBIGIIDAIBE CORPORATION, A CORPORATION OF DELAWARE BEIBIGEBATING APPARATUS Application filed December 1, 1924. Serial no. 753,043.

The present invention relates to refrigerating systems and particularly to the t pe of systems in which an automatic valve or expanding the refrigerant medium is used between the condenser and evaporator of the system.

One of the objects of the present invention is to provide a system in which the refrigerant medium enters the evaporator as a liquid and not as a gas. In this connection the valve is controlled by the pressure within the system and this pressure must be such as to cause liquefaction, and the valve is so constructed that the refrigerant medium cannot pass therethrough until the refrigerant has become a liquid.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompan ing drawings, wherein a preferred form 0 the present invention is clearly shown.

In the drawings:

Fig. 1 is a diagrammatic view of the refrigcrating system; Fig. 2 is a longitudinal sectional view of the valve used in the system; and Fig. 3 is a sectional view taken on the line 3-3 of Fig. 1.

Referring to the drawings, a compressor is shown at 20 driven by a motor 21 through belt and pulley connections 22. 23 and 24.

The inlet to the compressor 20 is connected with a pipe 25 which in turn is connected to an end of an evaporator 26. The refrigerant medium is drawn at a relatively low pressure from the evaporator 26 by the compressor and is expelled under relatively high pressure through the pipe 27 which 18 also connected with a condenser 28 herein shown, for illustrative purpose, as a water'cooled condenser. T e other end of the condenser 28 is connected by a pipe 29 to a valve 30. The valve 30 is connected by a pipe 31 to the inlet of the evaporator 26. Valve 30 withholds the flow of refrigerant medium from the condenser 28 to the evaporator 26 until the refrigerant medium is liquefied.

Current for the motor 21 is supplied by conductors 33 and 34, conductor 33 is pro- 50 vided with cooperating contacts 35 and 36 for controlling the starting and stopping of the motor. These contacts are operated by a snap switch 37 which is controlled by a bellows 38. The bellows 38 is connected by a tube 39 to a bulb 40. The bulb 40, tube 39 and bellows 38 form a closed circuit containing a volatile fluid which is responsive to the temperature of the evaporator and adapted to cause the expansion and contraction of the bellows 38 and thereby actuate the switch 37.

The valve 30 comprises a body 45 into which is screwed an end member 46 which forms with said body a hollow chamber 47. The pipe 29 is connected with a chamber 47 by a coupling 48 and the pipe 31 is connected with an extension 49 of the end member 46 by a coupling 50. The upper end of the body 45 is provided with a boss 52 into which is screwed a shaft 53 which extends also through the boss 52. The shank 53 is rovided with afiange 54 to which one en of the metallic bellows 55 is attached. The other end of the bellows 55 is connected to a flange 57 which is provided with a shank 58 adapted to slide within a hollow guide 59 in the extension 49. End 54 merges into a sleeve 60 and is adapted to receive a boss 61 which is located on the opposite side of the end 57 from that of shank 58 and projects upwardly a substantial distance into the sleeve 60. A spring 62 is interposed between the end 54 and the top of boss 61 and is located within the sleeve 60 and normally tends to force the boss 61 and likewise the shank 58 downwardly. Shank 58 carries a valve 63 adapted to cooperate with a seat 64 formed within the extension 49. Shank 55); is provided with flat surfaces 65 (see Fig. 3 .7 pass between said shank andvthe uide 59. The valve 63 controls the flow of re rigerant medium from the valve body chamber 47 through a passage 66 which leads to the-pipe 31. The boss 52 has an enlarged opening 67 at the upper end thereof for receiving packing 68 and a packing gland 69 screwed into the opening in the boss 52 and provided with screw driver or spanner wrench slot. 69". Shank 53 is provided with a central bore 70 for the purpose of introducing a. fluid into whereby the refrigerant medium maythe bellows 55. The end of the shank 53 is sealed by a screw 71 and packing 72. A cap 73 is screwed into the opening in the boss 52 and the joint is sealed with the aid of packing 74. The bellows 55 contains a quantity of fluid having the same characteristics as the refrigerant medium.

An i suitable refrigerant medium may be used in this system, however, sulphur dioxide is used for explaining the operation of the device.

\Vhen the compressor is idle, the temperature of the refrigerant medium in pipe 27, condenser 28, pipe 29, and valve chamber 47 is substantially the same as the environment atmospheric temperature. Likewise the temperature of the fluid in the bellows 55 is substantially the same as the environment atmospheric temperature. Therefore, the gas pressure in the bellows 55 and in the chamber 47 is substantially the same. However, the spring 62 acting within the bellows 55 maintains the valve 63 on its seat 64.

\Vhen the compressor :20 operates to compress and heat the gas, the heated gas entering the chamber 47 comes in contact with the bellows 55 and heats the fluid therein whereby the temperature and likewise the pressure within the bellows 55 increases to substantially the same degree as the increase of temperature and pressure of the gas within the chamber 47. The spring 62 however provides the necessary pressure for maintaining the valve 63 seated. It is apparent that the valve 63 will remain seated as long as the gas entering chamber 47 heats the fluid within the bellows 55 to substantially the same temperature as the gas in said chamber.

From experimental tests it is believed that the valve 30 operates as follows:

Liquid refrigerant leaving thebottom of the condenser and entering the chamber 47 is of course the coldest liquid in the system, due to the inherent method of operation of the condenser. This liquid surrounds and imparts its temperature to the liquid confined within the bellows 55. The latter liquid therefore exerts on the bellows a pressure whose value is the vapor pressure of the liquid at that particular temperature. However, it is obvious that all of the refrigerant passing thru the condenser cannot be liquefied instantaneously at the outlet point, that is at the coldest point. Therefore, some refrigerant must be liquefied in some of the upper COllS of the condenser, in other words at a warmer point than the outlet. This naturally requires a higher condensing pressure. Hence, the compressor builds u the pressure to the value necessary to con ense the refrigerant at this higher temperature. This elevated pressure value is therefore higher than the vapor pressure of refrigerant at the temperature exist- ,ing within the bellows. This pressure is obviously transmitted to the outside of the henlows and when this excess of pressure is sufficient to overcome the tension of the spring 63, the bellows will collapse and a quantity of the liquid refrigerant will pass out of the valve, thus relieving the excess pressure within chamber 47 to again establish an equilibrium. When an equilibrium is again established, .the valve will close. The adjustment of the valve is such that the valve will close after a quantity of the liquid refrigerant passes therefrom.

By providing the bellows 55 with a fluid having substantially the same characteristics or pressure-temperature curve as the'refrigerant medium, the pressure emitted by said fluid, plus the pressure of spring 62 is sufficient to maintain the valve 63 closed when the temperatures of the refrigerant medium of the system and the fluid in the bellows are substantially the same. Therefore, since the spring 63 counteracts the differential in pressures between the pressur s within the bellows 55 and the chamber &7, it is necessary only to provide a differential in ressure within chamber 47 and bellows 55 s ightly in excess of the tension of spring 63 before the valve opens. It follows, therefore, that the same differential in pressure is always necessary between the pressures of the fluid in the bellows and chamber before the valve 0 ens, regardless at what temperature the re rigerant medium condenses within the system. Thus, a valve has been provided which will function properly, although the temperature of the condenser cooling medium is variable.

If it is desirable to place the valve 30 within the compartment for the evaporator 26, the tension of the spring 62 would be increased because, when the compressor is idle, the temperature of the fluid within the bellows 55 will be substantially the same as the temperature of the compartment, and the pressure of the fluid in the bellows will be relatively low. The spring tension must be increased to such an amount that the relatively warm refri erant medium gas will not collapse said hilows when the compressor is operated. In will be understood that the refrigerant medium will heat the fluid in the bellows to a certain extent to increase the pressure of said fluid and said refri erant will be cooled to a considerable degreeTJy coming in contact with the cold walls of the chamber 47 and, therefore, liquefy before the pressure thereof is sufficient to collapse the bellows. It will be apparent, therefore, that the valve 30 can be located adjacent the evaporator or outside of the compartment cooled by said eva rator.

While the form of embodiment o the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A system of refrigeration comprising, in combination, a closed circuit inc uding an evaporator, means for expanding the refrigcrating medium in the evaporator and withdrawing the medium from the evaporator and condensing the same, a valve for controlling the passage of medium from the high pressure side of the circuit to the evaporator, and means responsive to pressure on the high pressure side of the circuit and operated when a quantity of liquid medium accumulates in the high side of the circuit for opening the valve.

2. A system of refrigeration com rising, in combination, a closed circuit inc uding an evaporator, means for expanding the refrigerating medium in the evaporator and withdrawing the medium from the evaporator and condensing the same, a valve for controlling the passage of medium from the high pressure side of the circuit to the evaporator, and means responsive to pressure on the high pressure side of the circuit and operated when a quantity of liquid medium accumulates adjacent said valve for 0 ening said valve.

3. A system of re ri eration comprising, in combination, a closer? circuit including an evaporator, means for expanding the refri crating medium in the evaporator and witl idrawing the medium from the evaporator and condensing the same, a valve for controlling the passage of refrigerant from the high pressure side of the circuit to the evaporator, means tending to open said valve in response to pressure in said high pressure side, means in opposition to the valve-opening means tending to maintain the valve normally closed, said 0 ening means being affected when liquid reii-igerant medium accumulates in said high pressure side whereby the valve will be opened to admit refrigerant medium to the evaporator.

4. A system of refrigeration comprising, in combination, a closed circuit including an evaporator, means for expanding the refri crating medium in the evaporator and withdrawing the medium from the evaporator and condensing the same, a valve for controlling the passage of refrigerant from the high pressure side of the circuit to the evaporator, means tending to open said valve in response to pressure in said high pressure side, means in opposition to the valve-opening means tending to maintain the valve nor- 'n1ally closed, said opening means being affected when liquid refrigerant medium accumulates in said high pressure side whereby the valve will be opened to admit refrigerant medium to the evaporator, said last-named means being again affected to close the valve when the accumulation diminishes.

5. A system of refrigeration comprising, in combination, a closed circuit including an evaporator, means for expanding the refrig crating medium in the eva orator and withdrawing the medium from t e evaporator and condensing the same, said circuit including a chamber in the high pressure side of the circuit, a valve for controlling the passage of refrigerant medium from said high pres sure side to the evaporator, means responsive to the pressure in tending to open the valve and means tending to oppose the pressure-responsive means but loosening its opposition when liquid refrigerant accumulates in the chamber.

6 A system of. refrigeration comprising, in combination, a closed circuit including an evaporator, means for expanding the refrigerating medium in the evaporator and withdrawing the medium from the evaporator and condensing the same; and means for controlling the flow of refrigerant to the evaporator including a refri erant chamber in the high-pressure side 0 the s stem, a valve for controlling the flow of ref i-igerant medium from said chamber, and a closed body within the chamber having a flexible wall adapted to be flexed in response to the conditions within said chamber for controlling said valve.

7. A system of refrigeration com rising, in combination, a closed circuit inclu ing an evaporator, means for expanding the re rigerating medium in the evaporator and withdrawing the medium from the evaporator and condensing the same; and means for controlling the flow of refrigerant to the evaporator including a refrigerant chamber in the highpressure side of the s stem, a valve for controllin the flow of re ri erant medium from said ciiamber, and a ffiaxible walled body within said chamber and containing a fluid having substantially the same characteristics as the refrigerant medium in the system, said fluid being subjected to the conditions within said chamber for controlling said valve.

8. A system of refrigeration com rising, in combination, a closed circuit inclu in an evaporator, means for expanding the re rigerating medium in the evaporator and withdrawing the medium from the eva orator and condensing the same; and means or controlling the flow of refrigerant to the evaporator including a refrigerant chamber in the high-pressure side of the system, a valve for controlling the flow of refrigerant medium from said chamber, a flexible walled body within said chamber and containing a fluid having substantially the same characteristics as the refrigerant medium in the s); tem, said fluid being subjected to the conditions within said chamber for controllin said valve, and a differential spring normal y tending to maintain said valve closed.

9. The method of cont-rolling the flow of the high pressure refrigerating medium from portion of a reportion to the low premure said high pressure side rigerating system, which method comprises withdrawing the refri crating medium in gaseous state from the ow pressure portion and compressing the same, obstructing the 5 flow of the compressed medium from the high Eressure portion to the low pressure portion y a pressure responsive device until a quantity of liquefied refrigerating medium accumulates 1n the high pressure portion, then m utilizing at substantia ly constant pressure the difference in temperature between the high pressure gas and the high pressure liquid for operating the pressure responsive device. In testimony whereof I hereto afiix my signature.

JESSE G. KING.

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