US2398262A

US2398262A - Refrigerating apparatus

Info

Publication number: US2398262A
Application number: US527267A
Authority: US
Inventors: Richard H Swart
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-03-20
Filing date: 1944-03-20
Publication date: 1946-04-09
Anticipated expiration: 1963-04-09

Description

April 9, 1946. R. H. SWART REFRIGERA'I'ING APPARATUS Filed March 20, 1944 FIGQI.

INVENTOR.

RICHARD H.5WART ATTORNEYS Patented Apr. 9, 1946 UNITED STATE s PATENT OFFICE This invention relates generally to refrigerating apparatus and refers more particularly to an improved device for controlling the flow of the refrigerating medium or liquid refrigerant from the receiver of the condenser to the evaporator or cooling unit of the apparatus.

One of the essential objects of the invention is to provide a device of the type mentioned that may be utilized in place of and has advantages over an expansion valve or a float structure or a capillary tube for controlling the flow of the re- For exfrigerating medium to the evaporator. ample, the commonly used thermostatic expansion valve is more expensive to manufacture, has 7 more moving parts and is apt to have leaks at the evaporator, with the result that'there is an important decrease in refrigeration efiiciency and cooling capacity of the evaporator just at a time when it is needed most. At' lower room temperatures than the specific conditions permitting correct feed, such tubes pass insufficient refrigerant for eflicient operation. Float valves, and expansion valves which are also commonly used for feeding refrigerants, require-a multiplicity of accurately fabricated parts which are expensive. and subject to wear and frequently need repairor replacement. Thus, the conventional devices mentioned are unsatisfactory or expensive to install and repair. 1

Another object is to provide a device having elements formed of materials provided with different thermal coefficients of expansion disposed in heat exchange relation to the return or suction conduit for the refrigerating medium flowing from the evaporator to the compressor so that slight variations in the temperature of the suction conduit will cause relative movement between the elements of, the device. r

The capillary tubes 7 Another object is to provide a device wherein one of the elements just mentioned is preferably in the form of a tube or conduit for the refrigcrating medium flowing from the receiver of the 66- condenser to the evaporator and serves as a valve seat for a valve carried by the other of said ele ments, so that the action of the valve to control the flow of refrigerating medium to the evaporator is responsive to relative movement between such elements.

Another object is to provide a device which will unload'the compressor at the start of a cooling cycle, by permitting the suction pressure and discharge pressure to equalize.

Another object is to provide a, heat exchange between the warm liquid refrigerant entering the device and the cold suction vapor returning from the evaporator in order to sccurehigh thermodynamic efllciency from the refrigeration system.

Another object is to provide a device for limiting the suction pressure of the compressor to a value below which the motor is not overloaded.

Another object is to provide a device that is simple in construction, economical to manufacture, easy to install and efficient in operation.

Other objects, advantages and novel details of construction of this invention will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawing-wherein:

Figure 1 is a diagrammatic view of refrigeratiim apparatus having a device embodying my invention;

Figure 2 is an enlarged fragmentary vertical sectional view through the return conduit and the device embodying my'invention;

Figure 3 is a sectional view taken substantially on the line 3-3 of Figure 2;

Figure 4 is a sectional view taken substantially on the line 4-4 of Figure 2;

Figure 5 is a view similar to Figure 3 but showing a slight modification.

Referring to the drawing, A is a device em- H, and J is a conduit for the refrigerating medium flowing from the compressor H to the condenser D.

As shown, the device A is in heat exchange relation to the return conduit F and preferably comprises a tube IU of stainless steel or other suitable material of low thermal expansion, a rod or wire ll of copper or other suitable material of high thermal expansion, and a valv I! on the rod I l and engageable with the 'adiacent end l3 of the tube Hi to control the flow of refrigerating medium from the tube iii to the evaporator E.

Preferably the tube III telescopically engages and is terminally connected to adjacent sections of the conduit B, while the rod I I within said tube is fixed or anchored at its forward end to the tube ill but otherwise is free with respect thereto. At its free rear end the rod II is threaded to permit adjustment thereon of the valve I2 so that such valve may be adjusted properly relative to its seat l3 at the adjacent end of the tube.

The forward end H of the rod may be flattened and soldered to a bell shaped portion I5 of the tube III, as illustrated in Figure 3, or may be fixed to a spider-like sleeve l6 rigid with the tube It, as illustrated in Figure 5. In fact, any suitable rigid connection between the forward end of the rod II and the tube I0 may be employed, as desired.

In use, the tube It ofthe device is soldered or otherwise secured in thermal contact with the return conduit F throughout substantial portions of their length, as illustrated in Figure 1 so that such tube III will be in thermal contact with said conduit. Thus, the tube I 0 serves as a heat transfer element between the return conduit F and the liquid flowing through conduit I0, thence to rod II. The rod II will therefore change in length with respect to conduit It as influenced by changes in temperature of the return vapor in conduit F. In a refrigeration system it is necessary to control the "superheat of the suction vapor in the evaporator outlet conduit to obtain eflicient performance of the system. If the temperature of the vapor is at or slightly above the evaporating temperature of the refrigerant, the presence of unevaporated liquid is indicated. If the temperatureof the vapor is abnormally high, the evaporator surface is inadequately utilized. Therefore, my device permits end of the tube I3 will be relatively great. This permits a greater rate of liquid refrigerant flow to the evaporator, resulting in the vapor superheat in conduit F decreasing. In case the Vapor becomes cooler than the desired superheat, the

conduit F receives additional heat from the inopen ended tubing having a cross section less than that of said feed conduit and extending throughout the ma! or portion of its length lengthwise of and in thermal contact throughout substantially its entire length with the exterior of said return conduit, said tubing of less cross section forming a part of said feed conduit for conducting refrigerating medium from the condenser to the evaporator, and means for modifying the output of said tubing of less cross section including a valve at the outlet end of said tubing, and an actuating rod for said valve fixed to said tubing at the inlet end thereof, said rod and tubing being formed of materials having difi'erent thermal coefficients of expansion so that a differential in expansion and contraction of said elements is obtained under varying temperature con-. ditions of said return conduit.

2. In a refrigerating apparatus of the compressor-condenser-evaporator type, the combination with a return conduit for conducting refrigerating medium from the evaporator to the compressor, of a feed conduit for conducting refrigerating medium from the condenser to the evaporator and including as a part thereof a double restrictor structure for controlling the flow of refrigerating medium to said evaporator, said double restrictor structure comprising a single length of open ended tubing having an outwardly flared inlet end and provided from said flared inlet end to its outlet end with a restricted coming liquid refrigerant, lowering the temperature of the liquid, the conduit ID and the rod I I.

As the conduit!!! androd ll cool, the rod II shortens with respect to tube'lfl, causing the valve I2 to move closer to seat I3, thereby restricting the rate of liquid flow. Thus, a subpressor, of a double restrictor structure in an evaporator feed conduit for controlling the flow of refrigerating medium from the condenser to the evaporator and comprising a single length of passage for the refrigerating medium, said tubing extending throughout the major portion of its lengthlengthwise of and in thermal contact throughout substantially its entire length with the exterior of said return conduit, and means for modifying the output of said tubing, including a valve at the outlet end of said tubing, and an actuating rod for said valve extending therefrom through the restricted passage aforesaid of said tubing and fixed to the flaredinlet of said tubing, said rod and tubing being formed of materials having diiferent thermal coemcients of expansion so thata differential in expansion and contraction of said elements is obtained under varying temperature conditions of said return conduit. p

3. In a refrigerating apparatus of the compressor-condenser-evaporator type, the combination with a return conduit for conducting refrigerating medium from'the evaporator to the compressor, of a feedconduit for conducting refrigerating medium from the condenser to the evaporator and including as a part thereof a double restrictor structure for controlling the flow of refrigerating medium to said evaporator, said double restrictor structure comprising a single length of open ended tubing provided throughout substantially its entire length with a restricted passage for the refrigeratin medium, said tubing extending throughout the major portion of its length lengthwise of and in thermal contact throughout substantially ,its entire length with the exterior ofsaid return conduit, and means for modifying the output of said tubing, including a valve at the outlet end of said tubing, and, an actuating rod for said valve extending therefrom through the restricted passage aforesaid oi said tubing and fixed to the said tubing at the inlet end thereof, said rod and tubing being formed of materials having different thermal coefficients of expansion so that a differential in expansion and contraction of said elements is obtained under varying temperature conditions of said return conduit.

said open ended tubing, including a valve at the outlet end of said tubing. and an actuating rod 4. In a refrigerating apparatus of the compressor-condenser-evaporator me. the combination with a return conduit for conducting refrigerating medium from the evaporator to the compressor, of a feed conduit for conducting refrigerating medium from the condenser to the evaporator and including as a part thereof a double restrictor structure for controlling the flow of refrigerating medium to said evaporator, said double restrictor structure comprising a single 1 length of open ended tubing extending throughout the major portion of its length lengthwise of and in thermal contact throughout substantially its entire length with the exterior of 'said return conduit, and means for modifying the .output of 16 for said valve attached thereto at the outlet end of said tubing, said rod extending through and cooperating with the interior ofsaid tubing to form therein a passage of less cross section than said feed conduit, said rod being fixed to said tubing at the inlet end thereof, said rod and tubing being formed of materials having dif- RICHARD svvART.