US2352581A - Method of refrigeration - Google Patents

Description

J. F. WINKLER METHOD oF REFRIGERATION Filed July 11, 1941 INVENTOR @wl Il A Josspn Ewmkuin 11111 [IIIIIIIU UIIIIIIII June 21, 1944.

VII w ATTORNEY Patented June 27, 1944 assi/,581

UNITED STATES PATENT OFFICE \rm'rnon oF nEFmGERA'rIoN Joseph F. Winkler, Philadelphia, Pa.

Application July 11, 1941, sena1N.4o1,s99

z claims. (cm2-17s) In the art of refrigeration it has heretofore been the practice to utilize a liquid or a gaseous refrigerant having the desired boiling point and coeiiicient of expansion, said medium being compressed and cooled to a certain extent and then permitted to expand or evaporate thus absorbing heat and effecting reduction in temperatures. Under this practice the pressureV in the evaporator as well as in the condenser, and the critical 'temperature in the condenser, had to be maintained at requisite figures (which varied-with the .the refrigerating apparatus nature of the medium used) which in most cases 'were relatively high in the case of pressure and relatively low in the case of temperature if low temperature refrigeration was to be achieved. More specically the evaporator side of the apparatus had to be maintained in a state of substantial vacuum in order to permit complete and rapid evaporation or expansion .of the refrigerating medium so as to .utilize to themaximum the I. heat absorbing capacity of the refrigerating me- The pistons I0 and I2 are provided with the by the amount of ammonia gas that could be I absorbed in a given amount of water at a given t carrying out the novel method referred to, the

full nature and advantage of which will be more clearly understood from the following specification and the accompanying drawing in which:

Fig. 1 represents a diagrammatic view, partly in vertical sectionand partly in elevation, illustrating the general construction and operation of embodying this invention.

Fig. 2 represents, on an enlarged scale, a vertical cross section of the` control valve intermediate the expansion and compression sides of the apparatus. y

Referring tothe drawing in which likereference characters indicate like parts. 4 designates a pump cas'ing having the low pressure cylinder 6 and the high pressure cylinder 8 in which operate respectively the pistons III and I2. The pistons III and I2 are actuated by the crank shaft I4 which is provided with the pulley I6 which is driven from any source of power (not shown), it being understood that any other means for driving the crank shaft I4 may be employed.

check valves I8 and 20. 22 represents an outer condenser within which is enclosed the inner condenser 24, there being a space or chamber 26' formed therebetween. From the low pressure cylinder 6 a pipe 28 leads to the chamber 26 between the outer and inner oondensers 22 and 24, and from the chamber 26 the pipe 38 leads back into the high pressure cylinder 8. From the high pressure cylinder 8 the pipe 40 leads into the inner condenser 24 which also contains the cooling coil 42 which is connected by means of the pipes 44 and 46 with the cooling apparatus generally designated as 48 and which may be of any desired conventional type. 50 designates a fluid control or other valve mechanism which regulates the iiow of the condensed refrigerating media 52 in predetermined quantities into and through the pipe 56 to the expansion chamber 58 which is preferably insulated as at 60. 62 designates a pipe controlled bythe valve 64 serving to carry the condensed lubricant 66 from the chamber 26 back into thel crank case 68 of the pump assembly 4. If it is desired to use a series of expansion chambers for successive utilization of refrigerating media, the pipe l0, which leadsto the upper expansion chaxber l2, is suitably connected either to the interior of the pipeA 54, to the lower or next preceding expansion chamber 58, or to the pipe 66. Similarly, if it is desired to utilize some of the higher boiling unevaporated refrigerant in the expansion chamber 58 for the vpurpose of relatively higher temperature refrigeration,the pipe 'I4 is used whichl leads to and through the pump 16 which is operated by the crank shaft I4, the refrigerant being then passed through the pipe 'I8 into and through the cooling coil 8l)v from the other end of which therefrigerant returns to the expansion chamber 458 by means of the pipe 82. The expended refrigerating medium is removed from the expansion chamber 58 thorugh the pipe 84 and the control valve 88, which is shown in detail inV'Fig. 2. '88 designates a wick which extends into the pipe 84 leading to the valve 88 for a purpose hereinafter more fully explained.

Referring to' Fig. 2, it will be seen that the valve 86 which communicates with the expansion chamber 58 through the pipe 84 also leads to the low pressure cylinder 8 through the pipe 90. The valve 85 comprises the stem 92 which carries the lvalve head 94 which is adapted to seat upon and close the throat 95 intermediatethe inlet pipe 84 and the outlet pipe 80. The valve stem 92 is constantly urged upwardly by the spring 98 so as to keep the valve head 94 in an upper position and keep the throat 98 normally open. In this condition the bellows |02 is collapsed (upwardly) throat 96 as shown in Fig. 2. Where a. series of expansion chambers are used (such as'the additional expansion chamber 12) the pipe |04 connects with the pipe 84 so that the expended refrigerating medium from the second (or third, etc.) expansion chamber 12 leadsinto the valve 88 through the common pipe 84.

'Ihe operation is as follows:

The inner condenser 24 is charged with a predetermed amount of selected gases havin'g the de. sired characteristics, but in actual practice I prefer to use propane gas (CsHa) and ethane gas (C21-Is) in the ratio of approximately 30% ethane and 70% propane. Propane, under one pound pressure, has aV boiling point of approximately minus 45 F. While ethane at the same pressure has a boiling point of approximately minus 125 F. Propane will liquefy at a temperature of plus 90 F. (or less) and under compression of about 150 pounds, and ethane at about the same critical temperature will need about 750 pounds pressure in order to liquefy. By combining ethane with propane inabout the ratio suggested, I am able to operate at a critical condenser temperature of plus 90 F. or less and at about 150 pounds pressure inthe condenser or less. In other Words, the combined ethane and propane will have the critical liquefying pressure and temperature ofv propane gas alone as long as the critical liquefying temperature of ethane (alone) which is about 90 F. is not exceeded. Why this is so, and whether or not a chemical reaction takes place, I cannot at this time explain. The fact remains that despite the individual characteristics of propane and ethane as above set forth when used alone, they do behave as I have explained and this has been established by the continuous, successful and eihcient operation of a machine built according to the present disclosure and run for a considerable length of time under actual commercial production conditions. Also I have noted that by this arrangement the propane in the liquid state can be used as an auxiliary or relatively higher temperature refrigerating medium throughout the cycle of operation While the more volatile and lower boiling point ethane serves as the main or practice. and starting with a mixture or solution of ethane and propane gas as at 52, and with the pump 4 in operation, the refrigerating medium as controlled by the valve 58 passes through the pipe 5'4 into the expansion chamber 58 (and in the event of multiple expansion chambers into the chamber 12, etc.). Here the mixture of ethane gas and propane gas, under a pressure of about one pound, evaporates and results in the required heat exchange to refrigerate the receptacle (and |08, etc.). Since some of the lubricant 88 inevitably passes through the system, the wick 88 is utilized which, by capillary action, continuously transfers liquid propane and the admixed lubricant from the expansion chamber into the high compression cylinder 8 from which,

through the pipe 40, the mixtureis fed directly over the cooling coil 42 where it is condensed into liquid as `at 52 to repeat the cycle. Excess lubricant collecting as at 66 is fed back into the crank case 58 through the pipe 62 and valve 64.

Any unevaporated or liquid propane remaining in the expansion chamber 58 may, if desired, be

utilized for secondary refrigeration by being conducted through the pipe 14 which communicates with the bottom of the expansion chamber 58, through the pump 16, the pipe 18, the cooling coil 80 and back through the pipe 82 into the expansion chamber 58. It will be noted that because liquid propane is heavier than liquid ethane, the communication of the pipe 14 with the bottom of the expansion chamber 58 wll result in substantially pure liquid propane being drawn oi through the pipe 14 and through the circuit including the expansion coil or cooling coil 80.

The liquid propane flowing through the pipe 18, cooling coil 80 and pipe 82, evaporates and the vaporized propane mixes with the ethane which vaporizes in the chamber 58. By this means, the differential in the evaporation of the ethane and propane is compensated for and the mixture of 20 per cent ethane and 70 percent propane with which the system was initially charged, is maintained substantially constant.

tained which operates under one pound pressure in the expansion chamber or chambers 58, 12, etc., under maximum pressure of about 150 pounds in the compression side of the apparatus, and at a critical temperature of 90 F. or less on the condenser side of the apparatus. Also by this means multiple refrigeration at different temperatures is attainable with automatic self-lubrication and automatic separation of the lubricant from the refrigerating medium. The evaporation of the ethane in the chamber 58 serves to maintain at least a part of the propane in the liquid state due to the latters relativelyhigher boiling point so that the propane is available for use in the liquid state as a higher boiling refrigerant.

In order to equalize the pressure between the chamber 26 and the interior of the crank case 68, I utilize the small caliber pipe or conduit 408x.

low temperature refrigerating medium. In actual 75 The pressure-regulated valve 86 permits continuous and uniform operation of the pistons 8 and 8 by preventing development of extreme pressure' atany given point throughout the apparatus and also permits starting oi' the pump by a motor having a relatively low starting torque. Since ethane has a boiling point of about minus 125 F., it will be seen that when my refrigerating ap` paratus has reached its maximum rated efliciency very low temperature refrigeration, extending .Well below zero is attained and maintained. It

will also be seen that in addition to direct and extreme refrigeration of any given object U08, IUI, etc.) my refrigerating system and apparatus also provide relatively higher temperature refrigeration by usel of the liquid propane-which in that state has a temperature of minus 45 F. or less.

Having thus described my invention, what I and a portion of said propane in a ilrst expansion chamber, vaporizing the remainder of the propane in a second expansion chamber, mixing the vapors produced in-both of said expansion chambers, returning said mixture of vaporsto said first zone and reliquefying said mixture to start another cycle of operation.

2. The method of producing continuous low temperature refrigeration which includes mixing a minor portion of a rst gaseous medium having a. relatively low boiling point and a relatively high liquefying pressure, with a major portion of a second gaseous medium having a relatively higher boiling point and a relatively lower liquefying pressure at a predetermined temperature. liquefying the mixed gases at the liquefying pressure and temperature of said second medium, evaporating substantially all of said iirst medium and a portion .of said second medium in a ilrst expansion chamber, evaporatingvthe remainder of said second medium in a second expansion cham.- ber, and remixing and reliquefying the vapors oi' said rst and second mediato start another cycle of operation.

JOSEPH F. WINKLER.

Images