US2273213A

US2273213A - Method of charging refrigerating systems

Info

Publication number: US2273213A
Application number: US335441A
Authority: US
Inventors: Graham S Mccloy
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1940-05-16
Filing date: 1940-05-16
Publication date: 1942-02-17
Anticipated expiration: 1959-02-17

Description

F 17, 1942. s. s. mcLoY METHODOF CHARGING REFRIQERATING SYSTEMS Fi led m 16. 1940 Q m P w m E REFR/GiQANr BOMB COMDRE 55 Ol? A m .R

CONDENSER INVENTOR GQAHAM S. Ma 61.0w

ATTOR? WITNESSES: I 4A. M 4; M 946 Patented Feb. 17, 1942 Graham S. McCloy, Springfield, Mass, assignor to Westinghouse Electric 8; Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application May '16, 1946, Serial No. 335,441

8 Claims.

My invention relates to refrigeration apparatus, and more particularly t?) a method and apparatus for charging a refrigerating system with refrigerant and lubricant and for removing noncondensable gases from the system.

In charging a-closed refrigerating system it is necessary for several reasons to remove substantially all noh-condensable gases such as air from the system. The presence of non-condensable invention as will be apparent from the following description and claims taken-in connection with the accompanying drawing forming a part of this application, in which the single figure of the drawing is a, diagrammatic view of a refrigcrating system to which my invention is applied,

gases in the system is objectionable for several 10 reasons as is well known in the art. For example, the presence thereof causes high head pressures in the high'pressure side of the system, and hence reduces the efliciency of the system.

Heretofore, refrigerating systems generally id have been charged with liquid refrigerant by first drying the refrigerating system with warm air or inert gas and then evacuating the system with high vacuum apparatus. The apparatus for performing the evacuation portion of the process is expensive and slow in operation and, in addition, the refrigerant and lubricant with which the system is afterwards charged contains non.- condensable gases which are not removed by prior evacuation. Furthermore, such a system.

is not conducive to mass production methods wherein the refrigerating systems during assembly and charging are preferablyydisposed on .moving conveyors. This invention is an improvement on the systems disclosed and claimed Referring specifically to the drawing for 'a detailed description of the .invention, the refrigerating system includes a hermetically-sealed motor compressor unit l0 including a compressor H, a motor l2 for driving the compressor and a casing Iii-enclosing the motor and compressor, In normal operation a lubricant reservoir is disposed in the hermetically sealed casing ii for lubricating the moving parts of the com.- pressor unit-J0 such as the bearings 15 and I8. The inlet of the compressor shown at H is connected directly to a compressor head Hi so that refrigerant vapor is, withdrawn from an evaporator l9 through a conduit 2| and enters the compressor H without entering the interior of the sealed casing l3. The compressor ll discharges high pressure refrigerant gas into the casing I3 so that the interior of the casing I3- contains gas at substantially condenser pressure. The high pressure gas from the casing I3 is conveyed to a. condenser 22 through a conduit 23, Refrigerant is condensed. in the condenser 22 by the cooling action of air which is forced over the condenser by amotordriven fan 24.

. a suitable screen 25 to a capillary tube 26 which It is an object of the present invention to 5 regulates the flow of condensed refrigerant to turned to the compressor it through. the con- Ii; is another object of the invention to charge 40 a refrigerating system with both refrigerant and .lubricant bythe container methods disclosed in the aforesaid patents wherein both the refrigerant and lubricant for initially charging the system are contained in a container attached to the system during ch'arging.

It is a further object of the invention to charge a refrigerating system with both refrigerant and lubricant by the container methods disclosed duit 2| and the cycle is then repeated. The sys-' -tem is so designed that, at least under certain conditions, a mixture of liquid and gas is forced through th'e capillary tube 26, whichfact is important in the further operation and description of the invention.

' In accordance with the present invention, a

, .in the aforesaid patents and in which the mov- 50.

charging drum or vessel This provided, which vessel 21 contains substantially the exact charge of refrigerant and lubricant for charging the refrigerating system, both the refrigerant and lubricant charge having been carefully measured by weight. The refrigerant may be, for example, dichlorodifluoromethane, sold under the trade name of Freon-12 and the lubricant is preferably a high -grade mineral lubricant. The drum 21 is connected to the interior of the sealed casing I3 by a conduit 28 having a hand valve These and other objects are effected by .my

29 therein, which conduit, 28 is attached to a welded to an opening crating system is completed and before it is condensable gases present in charged, the system is first dehydrated, which is preferably effected by subjecting the same to a flow of warm dry airor inert gas for a sumcient time to substantially remove all the moisture from the system. After dehydration, the system, still filled with warm air or inert gas,

mospheric pressure and the entire systemis above room temperature, having been heated by the warm dry air or inert gas used for drying so that very little, if any, air from outside the system will enter it. v

The compressor may now be operated'for a short period, for example, about 5 minutes to\ effect partial evacuation of the low pressure side of the system. This operation is also known as' auto-evacuation, since it is effected by operation of the refrigerant compressor. The compressor withdraws non-condensable gases present in the. low pressure side ofthe system and discharges such gases to atmosphere through, the opening The pressure in the low pressure side of the system is thereby reduced to about 25 inches of vacuum or lower. The auto-evacuation step is, however, optional as the container 21 may be made of sufficient size to containall the nonthe system without auto-evacuation. I J

The drum 2'! and conduit-28 are then connected to the conduit 30 in .the sealed casing I3 I, with the hand valve 29.closed and preferably with the compressor H inactive. Afterthe drum 21 and conduit 28' have'been connected,

the hand valve 29 is opened and substantially all of the refrigerant and lubricant contained in the vessel 21 flows through conduit 30 and opening -3| into the sealed casing 13, by gravity, It'will, therefore, be apparent that lubricant ispresent in the'lsealedca sing very soon after the pinched off below the valve 29 and sealed.

valve 29 is opened .to provide for lubrication of r the bearings I5 and ii. In addition to the gravity flow of refrigerant into the sealed casing l3 the refrigerant pressure ,in the vessel 2'! at room on temperature is usually sufficient, to assist the gravity flow of refrigerant and lubricant. This is true of refrigerants, such as F 12, which have a pressure above atmospheric, at room temperacant M in the sealed casing l3. The non-con densable gases which are contained in the system at this time are circulated throughout the system 'withthe refrigerant since, as stated heretofore, the system is designed so that the cacs pillary tube 26 will pass a mixture of gas and liquid under these conditions. The compressor, therefore, removes gaseous refrigerant vapor'and non-condensable gases from the low pressure side of the system and discharges them into the high pressure side of the system including the interior of the sealed casing l3, the vessel 21 and the condenser 22. Most 'ofthe'refrigerant is con- I densed in the condenser so that a mixture of liquid refrigerant and gaseous fluid, both re- 76 frigerant vapor and non-condensable'gases, flows through the capillary tube 26.

A mixture of gaseous refrigerant at high pressure and non-condensable gases also flows through the

conduits

30 and 28 and into the ves- Sci 21. Because of the flow of gases into the was-- sel 27 the pressure therein increases. bomb is intimately connected with the high side, the pressure'ln it and the high side will rise at substantiallythe same rate. As the condensing pressure is approached, refrigerant vapor contained in the mixture begins to condense inasmuch as the vessel 21 is exposed to the ambient atmosphere which is usually at the same temperature as the air circulated over the condenser 22 by the fan 24. The liquid refrigerant resulting from-such condensation drains by gravity back into the system and tends to reduce the pressure therein sufficiently to effect the abovementioned flow of fluid mixture from the sealed casing l3 to the vessel 21. The non-condensable gases entering the vessel 21 are not condensed so that they accumulate within the vessel 21. During this time, non-condensable gases contained in the refrigerant and lubricant are also removed and are collected in the vessel 21. After the refrigerating system has been operated for a sufiiclent time, for example, an hour, to collect substantially all the non-condensable gases in the vessel 21, the tube 30 is preferably From the foregoing, it will be apparent that -I have provided an improved method of charging both refrigerant and lubricant into a refrigform, it will be obvious to. those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What I claim is:

l. Th method of charging a refrigerating system including an evaporator, a compressor, 'a condenser and an expansion device, with refrigerant and lubricant and removing non-condensable gases from said system, which method comprises connecting to the system a container containing refrigeranfand lubricant for charging the system, transferring refrigerant and lubricant from the container to the system, transferring -non-condensable gases from the system to the container by operating the compressor to effect flow of a mixture of non-condensable gases and refrigerant vapor into the container, condensing refrigerant vapor in the container and returne ing the refrigerant condensed in the container to the system.

2. The method set forth in claim 1 and further including closing communication between the system and the container and disconnecting the container from-the system.

Since the "the container from the casing,

3. The method of charging and removing'noncondensable gases from a refrigerating system including an evaporator, a condenser, an expansion device, and a c'ompresson enclosed in a gastight casing, which method comprises connecting; to said casing a container containing refrigerant and lubricant for charging the system, transferring refrigerant and lubricant fromthe container to the system, transferring non-condensable gases from the system to the container by operating the compressor to effect fio.w of a mix- 7. The method of charging and removing noncondensabie gases from a refrigerating system I including an evaporator, a condenser, an expanture of non-condensable gases and refrigerant vapor into the container, condensing refrigerant vapor in the container and returning the refrigerant condensed in the container to the system.

4.- The method of charging and removing noncondensable gases from a refrigerating system including an evaporator, a condenser; an expansion device and a compressor disposed in an enclosed casing in which high pressure refrigerant discharged from the compressor'is present,

which method comprises connecting to said'cas-- ing a container containing refrigerant and lubricant for charging the system, transferring refrigerant and lubricant from the container to the'system, transferring non-condensable gases from the system to the container by operating the compressor to efiect flow of a mixture'ofrnoncondensable gases and refrigerant vapor into the container, condensing refrigerant vapor in the containerand returning the refrigerant con-' 'densed in the container to the system.

5. The method'setforth in .claini 4 and further including'closing communication between the container andthe casing and disconnecting 6. Themethod of charging and removing noncondensable gases from a refrigerating system including an evaporator, a condenser, anexpansion device, and a motor and compressor disposed in an enclosed casing, which method comprises connecting to said casing a container containing refrigerant and lubricant for charging the syssion device, and a motor and compressor disposed in an enclosed casing in which high pressure refrigerant is present and which casing connects with said condenser, which method comprises l, connecting to said casing a container containing refrigerant and lubricant for charging the sys-- tem, transferring refrigerant and lubricant from the container to the system, transferring noncondensable gases from the system to the container by operating the compressor to effect flow of a mixture vof non-condensable gases and refrigerant vapor into the containen condensing refrigerant vapor in the container and returning the refrigerant" condensedLinthe container to the system.

, tern, transferring refrigerant and lubricant from the system. c

8. The method of charging and removing noncondensable gases from a refrigerating system' and including an evaporator, a condenser, an'expansion device, and a compressor. which method comprises connecting to the system a container containing substantially the exact initial charge of both refrigerant and lubricant for the system,

transferring refrigerant and lubricant from thecontainer to the system, transferring non-condensable gases from the system to the container by operating the compressor to effect flow of a mixture of non-condensable gases and refrigerant vapor into the co'ntainer condensing refrigerant vapor in'the container and returning the refrigerant condensed in the container to GRAHAM s. MccnoY.