US1972704A - Refrigerating apparatus and process - Google Patents

Description

Sept. 4, 1934- D. N. CROSTHWAIT, JR 9 5 REFRIGERATING APPARATUS AND PROCESS 3 Sheets-Sheet 1 Filed March 51, 1930 x mi QM ms R Q I ma Q NW NMU imm a Sept. 4, 1934. D. N. CROSTHWA IT, JR 1 1,972,704.

I REFRIGERATING APPARATUS AND PROCESS Filed March 31, 1930 v 5 Sheets-Sheet 2 1 3 9 Ali Julia floa /11611 lnlfen or I Sept ,4, 1934. D. N. CROSTHWAIT, JR 1,972,704

REFRIGERATING APPARATUS AND PROCESS Filed March 51, 1930 3 Sheets-Sheet 3 l 1 \w k.

Patented Sept. 4, I I

UNITE -f PATENT OFFICE 1,972,104 mzr'monmrmc APPARATUS AND rnocass David N. Crosthwait, in, mersheutowofrowa Application March 31, 1930, Serial No. 440,519 A 23cm. 0142415)" s This invention relates to a new and improved pressed-prior to the admixture of the vapor or gas refrigerating process and apparatus, and niore to be compressed with theactuating jet. Acparticularly to a closed cycle refrigerating system cording to my improved process, the fluid formin' which a high velocity jet of vaporized reing the actuating jet is surrounded prior to the frig'erant from the high pressure side of the sysformation ofthe jet by a jacket of the cooled tem is utilized to' condense and return the exand expanded vapor that is to be compressed 4' panded refrigerant from the low pressure side and returned to-the generator." In this manner,

- of the system to the generator or source of the the temperature of the jet-forming fluid is lowhigh pressure .fluid. v ered. j

I The general object of theinvention is topro- Another object of the invention is to provide vide a simple and automatically operating rean improved form of compressor especially adaptfrigerating machine which maybe operated uned to carry out the process briefly outlined hereder a variety of conditions, thatis free from movinabove and explained more in detail in the ing parts, and in whichra wide variety of .respecifications which follow.

. frigerants may be used such as liquids,.liquid Another object is to provide improved means solutions of a refrigerant in a solvent, or solids 'forcirculating the vapor from the evaporator such as salts from which vapors may be driven through' the jet compressor whereby to precool 01f. The circulation in the system is obtained the actuating jet fluid. entirely from pressure and temperature difier Another object is to provide improved means i ences in different parts of the system. Briefly for automatically controlling theflow of actuatdescribed, a body of the liquid refrigerant is heat-' ing fluid to the jet' so that the compressor will ed i a closed e at ng space whereby this reonly be operated after a predeterminedminimum' frigerant is vaporized under relatively high prespressure difierential hasbeen established and sure, and while still under this high pressure maintained between" the pressure of the actuat a heat iswithdrawn ina condensing co'il so as to 'ing fluid and the pressure of the vapor to be liquefy the refrigerant. By means of anexpancompressed.

sion valve of improved type, the liquefled'refriger- Another object is to provide automatic means ant is admitted in limited quantities into for controlling the generator in accordance with p rat r wh n it E p nds and vaporizes and temperature and pressure conditions existing in.

a b at s as to arry ut the d sir d rethe evaporator and generator, so that the heat frigerating process. A jet or stream of vaporized cycle -may be automatically repeated and so as refrigerant from the generator, under relatively to maintain t desired tem erature in the space high pressure and high velocity, is utilized to to be refrigerated. Y v I entrain a portion of the expanded refrigerant Another object is topmvide a imprdved means from the vaporizer, whereby the mixtureof rewhereby the liquefied refrigmnt from the frigerants will be condensed and returned to the pressor need not discharged ga t high pressure source in liquid form or as a liquid tire pressure existing in the; generator, but may vapor mixture. More specifically, this invention be temporarily discharged t an mt di to contemplates precooling the jet-forming fluid so receiver in winch a pressure lower t generator as toincrease the-efilciency of the process and to pressure is maintained, and subsequently mm Tedube the actuating vapor matically permitted to gravitate into the generaand entrained low pressure vapor to liquid form v 'befme it is returned 150 the high Pressure source' Another object' is to provide improved means In Prevmus forms kinetic exhausters whereby an absorption cycle can be combined compressors. the resulting temperature of the with the compression cycle go as to vreturn an mixture of the actuating and the vapor additional quantity oi. expanded refrigerant into' being compressed was at a higher temperaitgri the generator I than the initial temperature of the vapor a ther ob ects and advantages of this invention 15 compressed The actuating jet was cooled vii? be mort a apparent from the ollowing detailed c l h ted from the e ansion 2,5 3: l'g gigg i fiifi gases or gi being description of certain forms of apparatus apa e compresse 'b the jet as a result of the mixing 01' carrying out the principles of invention. I or the two but no previous attempt has been In the accompanying d w made, so far as kxiown'to me, to secure a cooling f Fig. 1 is a diagrammatic layout of the assem- 01 the actueting y the vapors to be combled refrigerating apparatus, shown in elevation.

taken differential control valve.

Fig. 8 is a partial elevation, similar to Fig. 1, showing a modified form of system utilizing an intermediate receiver for boosting up the pressure of the condensed refrigerant.

Fig. 9 is a partial elevation, similar to Fig. 1, illustrating the addition of an absorption jet.

Fig. 10 is a vertical central section through the right hand end of the jet compressor shown in Fig. 9.

. It is to be understood that many of the devices 1 shown in the drawings, especially such parts as are heretofore well known in the art, are merely indicated diagrammatically and might take a variety of suitable forms.

Referring first to Fig. 1, the principal elements of the refrigerating apparatus are the generator A, the condenser B, the heat-exchanger C, the expansion valve D, the evaporator E, and the jet-compressor F for returning the refrigerant to the generator A. The differential control valve G governs the flow of actuating high pressure vapor to the compressor F, and the re-circulator indicated at H maintains a flow of cooling low-pressure vapor into and through the compressor F. Other auxiliary devices will be subsequently described. It might be here noted that the parts A to F hereinabove identified constitute a closed system through which the same body of refrigerant or refrigerating fluid is continuously circulated. The relatively high pressure side of the system exists in the generator A, condenser '13 and expansion valve D. The low pressure side of the system extends through the evaporator E and the outer casing of compressor F. In this compressor the refrigerant is liquefied and returned into the high, pressure generator A. In general, the fluids flow through the various pipings in the directions indicated by the small arrows, and the high pressure side of the system may be considered to exist from the generator A to and through the expansion valve D. and the low pressure side of the system to prevail from expansion valve D back to the generator A.

The several constituent parts of the apparatus will now be described in somewhat more detail,

after which the cycle of operations will be described. The generator A is in the form of a closed tank or receptacle containing a body of liquid refrigerant. In the lower portion of generator A is a heating element 1, here shown in the form of an .electric heater deriving its power from the mains 2 and 3 through an automatic control switch indicated at 4. A thermostat 5, positioned adjacent the evaporator E, or so as to register the temperature in the space to be irefrigerated, controls the automatic switch 4 through connections 6 so that the heater 1 will be energized when the temperature at 5 rises above a desired maximum, and the supply of power to heater 1 will be cut off when the temperature has been lowered at 5 to the desired minimum. 7 is a pressure controller subject through pipe 8 to the pressure existing in generator A, and adapted through connections 9 to open the switch 4 when a predetermined maximum pressure is reached in the generator A and the high-pressure side of the system. The generator A is provided with a filling plug indicated at 10. It will be apparent that when the heater 1 is energized, the refrigerant in the generator will be vaporized and its temperature and. pressure is considerably insure is reached. It will be understood that gas or other forms of heating means could be used for raising the temperature of the refrigerant in generator A, the electric means herein briefly described being merely shown by way of example although particularly suited for this purpose.

The vaporized refrigerant under relatively high pressure flows through pipe 11 to the condenser E which is in the form of a pipe coil 12 or similar form of conduit having a large condensing surface. This condenser may be cooled either by air or by water or other liquids depending upon the rangeof pressures it is desired to operate the apparatus between. Ordinarily-atmospheric air will be sufficient to extract the desired quantity.

iii

drawn from the condensed fluid. In the form here shown, this heat exchanger C comprises a tubular casing 14 closed at its ends and provided with interior transverse partitions'15 and 16 adjacent its respective ends, these partitions being connected by a plurality of tubes 17 opening into the spaces 18 and 19 at the respective ends of the container. The refrigerant from-condenser B flows through pipe 13 into the chamber 18 and thence through pipes 17 to the chamber 19 at the other end of the casing. A pipe 20 serves toconduct the cooled and expanded refrigerant under low pressure from the evaporator E into the space or jacket 21 surrounding the pipes 1'7, this vapor flowing out through pipe 22 to the compressor F, as hereinafter described. The high pressure refrigerant flowing through tubes 1'7 will be further cooled by the surrounding jacket 21 of lower pressure refrigerant so as to more completely condense the same before it flows in liquid form through pipe 23 into the expansion valve D. While the use of the heat-exchanger C is preferred, this of the float type, although it could be either of 1 the fixed adjustment type or a spring loaded diaphragm operated type both of which are familiar to those skilled in the refrigerating art or,'if desired both the float type of expansion valve and the spring loaded diaphragm type may be used in conjunction. The float 24 carries a valve member 25 cooperating with a fixed valve seat 26. When the liquid level rises in the casing 2'7, the float 24 will be lifted to raise the valve 25 and permit a limited quantity of liquid to flow out through pipe 28, but as the liquid level falls within the easing 27, the float 24 will again reseat'the valve 25 to cut off the further flow of liquid refrigerant through the outlet 28. In this mannerlimited.

quantities of refrigerant are permitted to flow out into the lower pressure existing in the evaporator E and the return side of the system.

Before passing to the evaporator E, the refrigerant released from expansion valve D passes through the recirculator. H, shown in section in Fig. 6. The function of' this recirculator is to in sure a circulation of the low pressure cooling vapor through the compressor F', as hereinafter,

described. Referring to Fig. 6, the casing 29 of the recirculator is provided with an'upper externally threaded inlet 31, a similar side inlet 30 and a lower outlet 32. The pipe 28 leading from expansion valve D is connected with inlet 31, and the pip'e'33 leading to the evaporator E connects with outlet 32. A small pipe 34 leading from the compressor F connects with the suction inlet 30 at the side of casing 29. Preferably all of these 'connections will be made by what is termed a "solderless connection, the pipe end extending into, the exteriorly threaded nipple such as 30, and the couplingnut 35 which is threaded onto the nipple having an .inwardly extending end shoulder 36'adapted to force a gasket 37 against the interiorly beveled end 'portion- 38 of the nipple so as to'compress the. gasket (which may be of copper or a suitable composition) into fluid-tight engagement withthe pipe end. While this form of pipe connection is preferred, other suitable types of pipe joints might be used. The discharge nozzle 39 is threaded at 40 into the upper inlet passage of casing 29, the nozzle having an annular shoulder 41 to engage the upper interior wall of the casing and properly position the nozzle and insure a tight joint at this point. Preferably this nozzle is provided with a relatively small cylindrical throat portion 42 and a flared dischargepassage 43. A short converging inlet passage 44 leads to the throat 42. A delivery tube 45 is similarly threaded at 46 into the lower outlet passage of casing 29, and is provided with an annular limiting shoulder 47. The discharge end 48 of nozzle 39 terminates within the converging inlet passage 49 of the delivery tube 45. The inlet end 50 of the delivery tube terminates within'the suction chamber 51 of casing 29. The passage within the delivery tube comprises the converging inlet portion 49, an intermediate cylindrical portion 52 and a diverging portion 53 from which the fluids are discharged into the pipe 33. The liquid dischlarged from the expansion valve D through pipe 28 starts to vaporize as it passes through the recirculator H, and the contour of the passages through nozzle 39 and delivery tube 45 cause this jet of actuating fluid to be projected with some velocity through the recirculator, whereby the low pressure vapor introduced through pipe 34 into the suction chamber 51 will be partially entrained in the annular inlet passage 54 and carried alongthrough the delivery tube, wherein the mixed gases are again compressed in the expanded portion.53 of the passage and discharged into thepipe 33 through, which they are delivered through the evaporator E. It is only necessary that a relatively small suction effect be exerted in chamber 51 sufficient to induce. a flow of fluid through pipe 3 4'from the compressor F.

The evaporator E is in the form of a hollow shell provided exteriorly with a plurality of ribs 55 adapted to provide additional contacting surface with the air in the space to be cooled. It is towbe understood that the evaporator E (as well as the thermostat 5') is inclosed in the chamber or space that is to be refrigerated. The space 56 within the hollow shell of the evaporator may serve as 'a" receptacle for articlesto be frozen, 'such' as ice cubes. Theliquid refrigerant flows in through pipe 33 into the hollow space 5'? within the evaporator shelland therefexpands and vaporizes,-thus absorbing heat through the walls of the evaporator shell from the space to be cooled orthe articles placed therein- I The expanded refrigerant, now at a low pressure and still at a relativelyLlow temperature, flows out from the evaporatonE through pipe 20 to and through the heat exchanger C wherein it absorbs additional heat from the condensed high pressure refrigerant, as hereinabove described. The 'still relatively cool low pressure refrigerant then flows through pipe 22 to the compressor F. This improved jet compressor F is best shown in Fig. 2. This improved jet compressor is de-v signed so as to secure an increased heat exchange, and consequently a'greater pressure'difference and a greater compression effect upon the gaseous refrigerant from the evaporator, for the purpose of returning this gaseous refrigerant to the generatovf This compressor '1? comprises a" rather long tubular casing 58 provided with an' inwardly extending annular flange or collar 59 at one end, and an internally threaded portion 60 at the other end. The conduit 22 for the low pressure refrigerant is -threaded into an inletnozzle 61 adjacent the discharge end of the casing. The inlet nozzle member 62 for the actuating fluid is provided with a large central collar member 63 exteriorly threaded to engage within the internally threaded endportion 60 of the casing 58, and

with an exteriorlythreaded outer inlet nipple 64 which is connected (preferably by asolderless ll'fi .connection of the type hereinabove described) The inlet nozzle member 62 is provided with .a m

discharge nozzle 66 having a converging passage 6'? leading tothe discharge opening 68 which-is located slightly beyond the minimum diameter of thepassa'ge, that is the discharge end ofthe noz-' zle preferably flares outwardly slightly. 'A second nozzle member comprisesa nozzle'portion 69, a cylindrical shell 70 adapted to flt within the outer casing 58, and a connecting annular wall or web 71 provided with a circular series of openings or pas sageways '12. One end '73 of the hollow cylindrical 13o shell '70 is adapted to abut against the inner side of collar 63 on the first nozzle member 62. Similarly, a third nozzle member comprises a nozzle portion '14, a hollow cylindrical shell '15, and a connecting wall '76 provided with a circular series of openings '77. As will be hereinafter apparent, a greater number of nozzle members such asf69 and '14 couldbe used if desired in order to accordtube 78 is connected by means of a solderless con 1&-

V 5. nozzle members may all be inserted into the outer 30'. and returnedto the generator A.

nection 82 with the pipe section 83 leading back to the generator A. A one-way valve 84in pipe 83 is adapted toopen againstthe higher pressure existing in the generator. It will be apparent that the delivery tube '78 and the several interior casing 58 from the right hand end (as shown in Fig. 4) and then securely clamped in.place by screwing in the inlet nozzle member 62. Suitable gasket members 85 and86 may be inserted between the flange 59 and the end of delivery tube '78, and between the firstand second nozzle members, in order to insure fluid tight connections.

' The cooled low pressure refrigerant from the' evaporator flows in through pipe 22 to the chamber 80 surrounding nozzle member '74, thence through passages '7'7'to the chamber 8'7 surrounding nozzle member 69," thence through passages '72 to the chamber 88 surrounding the inlet nozzle 66. A relatively small outlet passage 89 is formedin the outer portion of inletnozzle member 62; leading from the chamber 88 to an outlet opening 90 into which is threaded the end of pipe 34 leading to the recirculator H. The outlet pas-j sage 89is of considerably smaller capacity than the inlet pipe 22, since only a portion of the low pressure gas is to be recirculated suflicient to insure a flow of this vapor through all of the chambers 80, 8'7 and 88, the greater portion of this vapor being entrained with the actuating fluid chambers 80, 8'7 and 88 will be substantially the low pressure existing in the evaporator E, whereas the pressure of the actuating fluid in inlet passage 91 will be substantially that-existing in v the generator A.' The low pressure vapor in chamber 88 will also be at a much lower temperature than the actuating fluid entering through passage 91 so that a heat exchange will occur between the actuating vapor and. the low pressure refrigerant through the wall of the nozzle 66. The converging passage 6'7 in nozzle 66 will be shaped to converge in proportion to the change in specific volume resulting from this heat exchange. The actuating fluid passing through the nozzle 66 will be subject to a drop in pressure and an increase in velocity so that when passing through the outlet orifice 68 which may or may not be diverging, it will expand adiabaticallyand its kinetic energy will increase so that a portion of the difference in the heat content at the two pressures will become available as kinetic energy. At the outlet 68 the pressure will havedropped to a critical valuesuch that thevelocity will enable a portion of the low pressure vapor in chamber 88' to be entrained in the annular passage 92 and carried along with the .actuating fluid into the second nozzle 69. A partial condensing action will also takeplace at this'point. The second nozzle 69 comprises a converging passage 92 leading into a diverging passage 94 which discharges into the converging passage 95 in the third nozzle 74,

which in turn discharges into the diverging passage 96 in the delivery tube '78. As the fluids pass through the second'nozzle 69 more heat will be abstracted by the jacket of cooler refrigerant in chamber 87, and the pressure will be further decreased, so that at the discharge end 9'7 the velocity and pressure will havesuch a value due to the proportioning of the "passage that more gas may be entrained from chamber 8'7 through the annular passage 98 and compressed and carried into the third nozzle '74. A further condensing action will occur here resulting in a decrease in the volume of the vapor-liquid mixture, and owing to the high velocity obtained here a portion of the energy may be utilized to start a further compressing action. At the discharge outlet 99 of the third nozzle more of the low temperature and low pressure refrigerant may be entrained, and a further condensing ac-.. tion is secured, and the fluids are dischargedinto the deliverytube '78. The diverging passage 96 in the delivery tube will decelerate the velocity of the fluid mixture so as to cause compression,

and the refrigerant now mostly liquefied, will be raised to'a pressure suificient to permit its discharge through pipe 83 into the generator A.

The energy of the jet stream will be concentrated on a small area at the inlet 99 of the delivery tube so as to enable it to overcome the generator pressure and force the liquids past oneway valve 84 and thence into the generator. It

should be noted that the passages provided for I I the introduction of gas into the actuatingstream are at a very gradual angle so that there will be a minimum of energy lost at these points.

It is to be noted that a countercurrent flow occurs in this jet exhauster, that is the vapor to be compressed flows in a direction opposite to that followed by the actuating jet fluid. This tends to give a uniform temperature difference between the gas entering from the evaporator and the actuating jet and whatever mixture may have been drawn into the actuating stream. As the cooled low pressure vapor flows through the chambers 80, 8'7 and 88 its temperature will be gradually raised, so that the cooler vapor will exist in the chamber 80, and the relatively warmer 'vapor in the chamber 88. It will also be apparent that the actuating fluid in the jet will be initially at a much highertemperature as it enters from the generator, than when it leaves the compressor with the entrained and compressed fluids. In this manner a substantially uniform temperature difference is maintained between the actuating-fluids passing through the several jet nozzles and the cooling fluid in the surrounding chambers.

The differential control valve G (best shown in Fig. '7) will now be explained. The main casing 100 houses the main; chamber 101 having the inlet port 102 with which inlet pipe 103 communicates, this pipe leading from the dome or separating chamber 104 of the generator A. The valve seat 105 is removably secured in-the entrance to outlet passage 106 leading to outlet port 107 in' which pipe 65 leading to 'the' compressor F is secured. The lower half of a diaphragm chamber isformed integrally with the casing 100, this portion of the casing comprising an outwardlyextending flange 108, an in- Q wardly extending flange 109, and a centrally and 'downwardly projecting cylindrical portion 110.

The valve member 111 which cooperates with valve seat 105 to close the passage through the valve, projects downwardly from a piston or guide member 112 which slides vertically 'inthis cylindrical passage in member 110. The upper casing member or cover 113 comprises an outwardly extending and downwardly dished flange portion 114 which mates with the corresponding flange portion 108 of the lower casing, and the peripheral portion of a flexible diaphragm 115 is clamped between'the two flange members 108' and 114 by'means of a circular row of bolts 116. A threaded stem member 117 projects through a central aperture in diaphragm 115, v and also through a pair of diaphragm plates 118 positioned at the two sides of the diaphragm,

' and is clamped sealing engagement with these members by nu s 120 and lock nuts 121. A head 122 on the lower end of stem 11'? engages in a transverse T-shaped slot 123 in the upper side of valve member 112 so as'to lock these parts together for simultaneous vertical movement. A

pressure control pipe 124' leadingfrom some portion of the low pressure side of the system, for example from the pipe leading. from evaporator E, communicates with the pressure chamber 125 above diaphragm'115." The relatively high 20 pressure-existing in chamber 101 will be communicated through piston 1121 to the chamber 126 beneath the'diaphragm 115. A compression spring 127 is confined between the upper nut 121 and a spring cup 128 bearing against'the g5 lower-end of adjusting screw 129 threaded through the cap portion 130 of ,casing 113.. A cap '131 maybe interiorly threaded to engage the upper ,end of screw 129, and a gasket 132 interposed between the capmembers 131 and 130 will eflec- 3 tively seal theopening.throughthe upper 'side oi thecasing." It' will now be apparent that the force of spring 1217v together with the low pressure communicated through control pipe 124 are exerted on the upper side of diaphragm 115, while the relatively high pressure of the actuating 'fluid 5 pressor 1 Inother words, until this maximum. pressuredifi'erential has been. reached, there canv be no flow of actuating pressure fluidto the jetcompressor F, so that a predetermined pressure taken fromthe generator A through pipe 103 is exerted: on the .under side-"of diaphragm 115, since chamber 101 communicates with diaphragm chamber 126'through passages 109. The ad- 0 justable force exertedby spring 12'7 will determine the pressure differential that must exist between the high and low pressure-fluids before the valvelll will open to permit the actuating fluid to pass through pipe 65. to the comdifferential must exist between thelow pressure refrigerant that is to be compressed, and the high pressure refrigerant used for actuating fluid be- .-valve;is preferred.

fore the operation of cally started. v

An ordinary pressure control valve, might be the compressor isautomati- 5 used in this system instead of the diflerential pressure control valve, although the differential a c 't-ofl valve 133 15' pipe 124, and this1contro1 pipe a branch 134,

. eaprovided: with a cut-oil, valve 135, and leading 7o visable.

. A into the. pipe 22 adjacent its connection with the .jetcompressor. F. -By properlropening one of the va1ves133 or 135 and closing the other, the

low pressure connection to differential. control valve (3 can be established either with the pipe 20 leading from evaporator E, or with the pipe .22"

" ,far described, assuming that the thermostat -5- suming that the maximum pressure notf leading into the Jet compressor F. gIn this way the-minimum pressure used for control purposes.

may be changed as conditions'may indicate ad- In thegeneral operation ofthe system "as thus caflls for heat to-b'ev abstracted from the space that\is being cooled by the evaporator, and as positioned in the control.

. operating the jet compressor, If desired or found necessary, one-way valves them, to insure the now 1 been established in the generator A, the switch liquefied, and from the condenser it flows through the heat exchanger Cwhere more heat is abstracted before the completely liquefied refrigerant flows into the expansion valveD. This valve feeds the refrigerant in limitedquantities through'the recirculator H to the evaporator E,

where the refrigerant again vaporizes at a low pressure sofas to extract considerable quantities of heat from the space tobe refrigerated. The cooled low pressure refrigerant flows "back through heat exchanger C, wherein it extracts some further heat from the incoming high pressure refrigerant, and then fiows through pipe 22 to the jet compressor F. The jet compressor will remain outof operation until a sufficient predetermined pressure difference has been established between the high and low pressure sides of the system, and when this pressure difference is obtained, thediflerential valve will open and admit actuating vapor at high pressure toflow from generator A through pipe 103, valve Gandpipe 65 to the jet compressorF. This jet compressor will operate as already described to return i the actuating high pressure refrigerant, together with an entrained portion of the low pressure refrigerant, both in a liquid condition, back i I through pipe 83 and one-way valve 84 to the generator A. A'portionofjhe lowpressure re- H frigerant flowing into the compressor F sufficient to maintains. constant flow of the cooling low pressure refrigerant through the compressor, flowsback through pipe 34'to the recirculatorH and thence passes again through the low pressure-side of the system: It will be evident that this cycleof operations will continue to'be reexceed a predetermined maximum, or the tem peraturein the space being cooled by the evaporator .does not decrease below a predetermined If the pressure in the generator exceeds the predetermined thepressure .peated as long as the generator pressure does not switch will shut off the current supply'to heater 1, and the heat supply will also be shut 011' in the same manner case the temperature in the space being refrigerated falls below the desired again falls below this critical pressure,- and the temperature in the refrigerated space again rises above the established minimum, the heater 1 will again be thrown into operation by the to.-

matic closing of switch 4.

Theheat exchanger C :might be omitted entirely, as might alsobe the recirculator H, although this latter is beneficial in insuring initial cooling of the suction space of thejet compressor min.imum. Whenever the generator pressure I F so-as to insure the desired heat'conditions and e pressure conditions for 'efliciently and reliably may be inserted in pipes 22 and 34, or either of offiuids in onlythe desired direction.

f- A modified form of the apparatus is shown in Fig; 8, the parts that are the same as. those jalready described inconnection with Fig. 1 being indicated by the same reference characters, and

' it being understoodthat features not shown in Fig. 8 are the sameas those used in the first described modification. An alternating receiver, or intermediate receiving tank for the liquefied refrigerant, is indicated at 136, this tank being positioned at ahigher level than the generator sure control pipe. 141 leads from the low pressure pipe 22*, and the valves alternatively establishing communication between these control pipes and the interior of receiver 136 are automatically controlled by afloat 142 in the manner well known-in apparatus of this type so. as to alternatively establish the high or low pressures in the receiver 136 in accordance withthe liquid level therein. The float 142 has a lost motion connection with the valve operating mechanism so that when a predetermined quantity of liquid refrigerant has been forced into the receiver 136, the valves will be manipulated to establish communication with control pipe 140 and cut off communication with control pipe 141 thus establishing generator pressure in the receiver 136.

When the tank has been emptied, or a predetermined quantity of liquid has beenwithdrawn therefrom, the high pressure connection will be cut off and the low pressure will be reestablished in the receiver 136. A valve 143is positioned in control pipe 141, this valve being of a type that opens at a predetermined maximum pressure. This valve will be so adjusted that'a pressure somewhat higher than that existing in the low pressure-side of the system must be'established in the receiving tank 136 before this valve will open to prevent a further raisingof the pressure in the receiver. i I

In the operation of thismodified form of the.

system, the high generator pressure will .exist from generator A back to the one-way valve 138,,

but the jet compressor F is not compelled to discharge the liquefied refrigerant against this high pressure, the refrigerant being forced through pipe 83, one-way valve 137 and branch pipe 139 ihto the receiving tank 136 in which a pressure I exists intermediate that in* the generator A and the low pressure in pipe 22. When a sufficient quantity of the liquid refrigerant has been forced into the receiver 136, the float controlled valves will be automatically operated to establish generator pressure in the tanlr136, 'vfiiereupon this body of refrigerant will gravitate through pipe 139, one-way valve 138 and pipe '83 into the generator A. As the receiver 136 is emptied, the float control valves will' again be automatically manipulated to reestablish the intermediate pressure in the-receiving tank 136. It will be noted that by the use of this auxiliary mechanism, the'pressure is reduced against which the jet compressor F mustoperate. I 4

y In the systems as thus far described, it has been assumed that an undiluted refrigerant was 'used. If a gas dissolved in a liquid is used, such as ammonia dissolved in water, the apparatus may be 'mo'dified as indicated in Figs. 9 and 10. In this modification; a small pipe 144 leads from the lower portion of generator A into the inlet end of the compressor F and terminates in a discharge will be absorbed by t nozzle 145 centered within the first discharge nozzle 66 of the compressor as already described. This pipe line 144 serves to conduct a stream of weak water-ammonia mixture from the lower part of the generator, but l nder high pressure, into the compressor where it is discharged as a central liquid jet within the high pressure vapor I jet as already described. Preferably a pressure control or differential control valve G is included in the pipeline 144, this valve operating similarly to the control valve G and being under the control of generator pressure through control pipe 146. If desired a single control valve G could be designed to control both the liquid jet and the vapor jet. Since the amount of ammonia which will be absorbed by water increases as the t temperature decreaseskegas from the evaporator liquid discharged from nozzle 145, so that this weak mixture will be con- 1 verted into a strong mixture which returns to the generator along with the condensed gases. The advantages of a compression and an adsorption system are thuscombined.

It may be noted that refrigerating systems such as disclosed hereinabove are particularly-applicable in the field of small domestic refrigerators,

since the system is entirely closed, there are no moving parts and the flow areas are-relatively small. The operation of the system is entirely automatic, and'the system. may be adjusted to maintain any desired temperature, within certain limits, in the space to be refrigerated."

I claim:

1. The method of refrigerating consisting in heating the; refrigerant in a closed generating 1 0 space to vaporize it under relatively high pres-- sure, condensing this refrigerant by extracting heat therefrom, expanding and vaporizing this refrigerant at a lower pressure, compressing and returning the low pressure vaporized refrigerant heating the refrigerant in a closed generating space to vaporize it under relatively high pressure, condensing this refrigerant byv extracting; heat therefrom, expanding and vaporizing this refrigerant at a lower pressure, and utilizing a jet of high pressure vaporized refrigerant from theclosed space to return the low pressure vaporized refrigerant to the generating space and simultaneously utilizing an envelope of the low pres-c 3 sure refrigerant to conglensethe mixture of returned refrigerants. 7

3; The method of refrigerating consisting in heating the refrigerant in a closed generating space to vaporize it under relatively high pressure, condensing this refrigerant by extracting heat therefrom, expanding and vaporizing this pressure vaporized refrigerant from the closed space to form a jet, precooling this fluid, and uni-1140 4."Ihe method of refrigerating consisting in 11 heating the refrigerant in'a-v closed. generating space to vaporize it under relatively high pressure, condensing this refrigerant by extracting heat refrigerant at a lower pressure, withdrawing high Q therefrom, expanding and ,vaporizing this re-. frigerant at a lower pressure, withdrawing high pressure vaporized refrigerant from the closed space ttx form a jet, surrounding this jet-forming fluid with low pressure refrigerant to precool the Jet, and utilizing the jet to return a mixture of 5 condensed jet fluidand the low pressure refrig'-.

erant to the generating space.

5. The method of refrigerating consisting in heating the refrigerant in a closed generating. space to vaporize it .under relatively high pressure, condensing this refrigerant by extracting heat therefrom, expanding and vaporizing this refrigerant ata lower pressure, withdrawing high pressure vaporized refrigerant from the generating space to form a jet and utilizing this jet to liquefy a temperature-controlled mixture of the jet fluid and iow pressure vaporized refrig- 'erant' and td force this mixture into an intermediate receiving space positioned at a higher level and normally under a lower pressure than the generating space, and equalizing the pressures in the generating space and receiving space when a predetermined volume of liquefied. refrigerant has accumulated [in the receiving space whereby the liquefied refrigerant will gravitate into the generator. I v 6, The method of refrigerating consistingin heating the refrigerant in a closed generating space .to vaporize it underrelatively high pres- I sure, condensing this refrigerant by extracting heat therefrom, expanding and vaporizing this refrigerant at a'lower pressure, and utilizing a jet of high pressure vaporized'refrigerant from the closed'space to return the low pressure vaporized refrigerant to the generating space and simultaneously condense. the mixture of returned refrigerants; and simultaneously utilizing a jet of liquefied refrigerant from the generating space to absorb ,a portion 'of the vaporizediow pressure 2 refrigerant and return same to thegenerating' space. v 1 '7. The method of refrigerating consisting in heating the refrigerant in; a closed generating space to vaporize it'under relatively high pressure, condensing this refrigerant by extracting heat therefrom, expanding. and-vaporizing this l'flfi'lfl. erant at a lower pressure, withdrawinghigh pressure vaporized refrigerant from the closed space to form a jet, surrounding this jet-forming fluid with low pressure refrigerant to precool 4 the jet, and utilizing the jetto return a mixture of condensed jet fluid and the low pressure re-. frigerant to the generating space, and simultaneously utilizing a jetof liquefied refrigerant from F the generating space to 'absorb aport-ion of the 55 vaporized low pressure refrigerant and return same to thegeneratin Space. v of 8. In a method of refrigerating, the step condensing and returning low pressure vaporized refrigerant to a body' of liquid refrigerant ina. generator under higher pressure by utilizing a'jet of the higher pressure refrigerant from the generator, entraining in the jet a portion of the low pressure refrigerant and cooling the mingled fluids'by surrounding the jet with a jacket ofthe low pressure refrigerant.

e 9. In a method of refrigerating, the step. of condensing and returning low pressure vaporized refrigerant to a body of liquid refrigerant in a generator under higher pressure by utilizing a jet of the higher pressure refrigerant frgm the generator, precooling the jet-forming fluid by surrounding it with the low pressure refrigerant, and then entraining in the jet a' portion of the low pressure refrigerant.

erafl t; the step 10. In a of refrig generator and entraining in the 16'. A closed cycle refrigerating apparatus condensing and returning low pressure vaporized refrigerant to a body of liquid refrigerant in a generator under higher pressure by utilizing a jet of thehigher pressure refrigerant from the generator, precoolingthe jet-forming fluid, and then 80 entraining in. the jet a portion of the low. pressure refrigerant. Y

11. In a method of refrigerating, the step of; condensing and returning low pressure vaporized refrigerant to a bodyof liquid refrigerant in a 88' generator under higher pressure by utilizing the momentum of a streamof the refrigerant at high velocity to entrain and compress a mass of the gas at a lower pressure and simultaneously-cool: ing the intermingled fluids by surrounding the stream with a counter-flowing stream of the low pressure refrigerant. f

- 12. In a method of refrigerat ing, the step of condensing and returning low pressure vaporized L refrigerant to a 'body of liquid refrigerant in a generator under higher pressure by utilizing a jet ofthe higher pressure refrigerant from the v jet and condensing a portion of the low pressure refrigerant, the condensed mixture being first forced into an 100 intermediate space positioned at ahigher level and in which a pressure lower than generator pressure prevails, and establishing generator pressure in this intermediate space wherever a predetermined volume of liquefied refrigerant has accumulated therein so that the liquefied refrigerant may gravi t e into theg'enerator.

I 13. A closed c cle refrigerating apparatus com prising a generator, a condenser, an expansion valve, an evaporator, and a jet'compressor, the i compressor including means for utilizing astream of high pressure refrigerant from the generator to compress low pressure refrigerant from the evaporator and return the mixed fluids to the generator the mixed fluids being simultaneously condensed by means of a counter-flowing envelope of the low pressure refrigerant.-

.14: A closed cycle refrigerating apparatus comprising a generator, a condenser, an expansion valve, an evaporator, and a jetcompressor, the compressorincluding nozzles through which a jet of high pressure fluid-from the generator i'spro I jected, and a cooling jacket surroundingrthe, nozzles through which the low pressure vapor-froml the evaporator is circulated before'a portion of this low pressure vapor is 'entrained'a'nd'condensed bythe jet and returned to the generator. 15. A closed cycle refrigerating apparatus comprising a generator, a condenser-, an--expansion valve, an evaporator, and a jet compressor, the,; compressor including nozzles through-which a jetof high pressure fiiiid from-the generator is projected,=and a cooling jacket surrounding the nozzles through. which the .low pressure vapor from the evaporator .iscirculated before a por-' tion of this low pressure vapor is entrained and condensed by the je and returned to the gem erator, and a recirc tor for maintaining a flow of the cooling refrigerant through the jacket, this recirculator comprising. a jet exhauster actuated bythexflow of refrigerant between the ex pansion valve and .the evaporator.-

05m prising a' generaton'a condenser, an expansion 1 valv'efan evaporator, and a jet compressontheu compressor including meansfor utilizing a stream of high pressure fluid from the generator to compress and condense low pressm'e refrig erant from the evaporatcr andretum the mixed fluids to the generator, and a diflerential valve when a predetermined'pressure differential has been established between the high and low pressure fiuids 17. A closed cycle refrigerating apparatus comprising a generatona condenser, an expansion valve, an evaporator, and a jet compressor, the

compressor including means for utilizing a stream of high pressureifluid from the generator to compress and condense low pressure refrigerant from the evaporatorand return the mixed fluids to the generator, andgpressure actuated means to automatically control the starting and stopping of the jet.

18. A closed cycle refrigerating apparatus comprising a generator, a condenser, an expansion valve, an evaporator, anda jet compressor, the compressor including means for utilizing a. stream of high pressure fluid from the generator to compress and condense low pressure refrigerant from the evaporator, a receiving tank into which the condensed mixedfluids are discharged from the compressor, said tank being positioned at a higher level than the generator, a discharge connection between the tank and generator provided with a one-way valve opening toward the generator, .and float-actuated means connected with the high and low pressure sides of the system for placing the contents of the tank under generator pressure when a predetermined liquid I level has been reached in the tank whereby the contents of the tank may gravitate into the generator.

19. In a refrigerating apparatus, in combination with. agenerator for s'upplying vaporized refrigerant under relatively high pressure and temperature, and an evaporator from which the refrigerant is returned at a lower pressure and temperature, a compressor for condensing and returning refrigerant to the generator comprising a casing, a plurality 'of jet-projecting nozzles arranged in tandem within the casing whereby one nozzle projects its jet into the next succeeding nozzle of the series, there being a plurality of connected chambers in'the'casing surrounding the nozzles, said chambers being in open com-- munication with the jets, connections for discharging high pressure refrigerant from the generator through the nozzles, and connections for 4 maintaining afiow of low pressure refrigerant into and through the chambers, the flow of low pressure refrigerant through the chambers being in the opposite direction to the flow of high pressure refrigerant through the nozzles.

20. A closed cycle refrigerating apparatus comprising a generator, a condenser, an expansion valve, a recirculator, an evaporator, a jet compressor and a return connection from the compressor to the generator, these elements all being connected in a closed series in the order named, pipe connections for delivering high pressure-refrigerant from the generator directly to the compressor through which it is projected as an actuating fluid and returned to the generator,

a differential-pressure control valve in this pipeconnection for permitting a flow therethrough only when a predetermined pressure differential exists between the high and low pressure sides of the system, and a pipe connection from the compressor to the recirculator for maintaining a partial flow of low pressure refrigerant from the compressor back to the evaporator.

21. In a compression system of refrigeration, the step of controlling the compressing operation in response to changes in the pressure differential between the high and low pressure sides of the system, the compression operation starting when the differential rises abovea predetermined minimum and continuing as long and only as long as the differential remains above this minimum.

22. In a compression system of refrigeration comprising a high pressure side including a gen-' erator, and a low pressure side including an evaporator, a compressor, and means. for controlling the compressor in response to changes inthe pressure difference between the high and low pressure sides ofthe system. a

23. In a compression system of refrigeration this high pressure refrigerant to the compressor.-

so that the compressor will operate when and only ,'when the pressure difference between the high and lowpressure sides of the system is above predetermined minimum. z

t I 'DAVID N. CRROSTHWAIT, JR;

Images