US2307165A

US2307165A - Refrigeration

Info

Publication number: US2307165A
Application number: US283351A
Authority: US
Inventors: Arnold D Siedle
Original assignee: Hoover Co
Current assignee: Hoover Co
Priority date: 1939-07-08
Filing date: 1939-07-08
Publication date: 1943-01-05
Anticipated expiration: 1960-01-05

Description

Jan. 5, 1943.

A. D. SIEDLE REFRIGERATIQN Filed July 8, 1959 4 Sheets-Sheet l INVENTOR Arnold D Siedle A'TTO RN EY A. D. SIEDLE REFRIGERATION Jaia. 5, 1943.

4 Sheets-Sheet 2 Filed July 8, 1939 INVENTOR Arnold D. Sz'edle ATTORNEY subjected.

REFRIGERATION Arnold n. Siedle, Canton, Ohio, assignor to The Hoover Company, North Canton, Ohio, a corporation of Ohio Application July 8, less, Serial No. 283,351

(or. oa -s) 17 Claims.

The present invention relates to the art of re frigeration and more particularly to a novel absorption refrigerating system including an improved method of circulating various fluids therethrough.

It is a principal object of this invention to provide an absorption refrigerating system of the three-fluid type in which circulation of fluids through the various circuits thereof is achieved by utilization of the static pressure dlfierentials extinguish in various portions of the apparatus.

It is another object of the present invention to provide an absorption refrigerating apparatus of the three-fluid type in which circulation of the fluids is achieved by alternately connecting various portions of the apparatus to high and low pressure areas therein.

It is'still another object of the present invention to provide a three-fluid absorption refrigerating system of thetype utilizing a power driven inert gas circulator to circulate the inert gas from which circulation of the liquid is achieved by means of static pressure differentials produced by the power driven inert gas circulator.

It is a still further object of the present invention to provide a three-fluid absorption refrigerating apparatus of the type utilizing a power driven circulator for the inert gas circuit inwhich when taken in connection with the accompanying drawings in which:

Figure 1 is a diagrammatic representation of Figure 4 is a diagrammatic representation of a modified form of the invention.

Figure 5 is a partial diagrammatic representation of another modification of the invention.

Figure i5 is a vertical sectional view on an enlarged scale of a valve assembly. a s

Figure 7 is a view taken substantially on the line 1-1 of Figure 6. 1

Figure 8 is a view of adetail of Figure 6. Referring now to the drawings in detail and first to Figures 1 and 2 thereof, there is disclosed .a three-fluid absorption refrigerating system comprising a boiler B, an analyzer D, .an aircooled rectifier R, a tubular air-cooledcondenser circulation of liquid is achieved by alternately connecting various portions of the apparatus to.

the suction and discharge sides of the circulator. It is a further object of the present invention to provide a three-fluid absorption refrigerating apparatus in which circulation of the absorption solution is achieved by periodically varying the pressures to which certain portions thereof are It is another object of thepresent invention to provide an absorption refrigerating system in which the liquid refrigerant is elevated from the bottom portion of the condenser into the upper portion of the evaporator by periodically subjecting-the condenser evaporator line to high. and low pressures.

It is a further object of the present invention to provide an absorption refrigerating system in which substantially continuous circulation of abis achieved by periodically subjecting a plurality I of portions of the absorption solution circuit to sorption solution between the boiler and absorber C, a liquid refrigerant reservoir- S'. an evaporator E, a gas heat exchanger G. an air-cooled tubular inclined absorber A, a liquid heat exchanger L, a solution reservoir 8, and a circulating fan F which is driven by an electrical motor M. The

The control mec for the circulating motor M and for the boiler heater, not shown, may be of any desired or preferred type. A preferred construction is disclosed and claimed-4n the co-pending application of Curtis 0. Coons, Serial No. 148,424, flled June 16, 1937., now Patent No. 2,228,343, dated January 14, 1941.

The application of heat to the boiler B generates refrigerant vapor from the solution of refrigerant vapor and absorption solution normally therein contained. The vapor so generated passes upwardly through the analyzer D in counterflow relationship to strong solution sow in; downwardly therethrough. After passing through the analyzer the refrigerant vapor is conveyed therefrom to the upper portion of the confinser C by means of the conduit II which includes the rectifier R. The refrigerant vapor is liquefied in the condenser by heat exchange with cooling air and is discharged from the bottom portion thereof into the liquid refrigerant reservoir S by means of a conduit i2.

The liquid refrigerant collecting in the reser-' voir S is conveyed therefrom to the finned box-.

tom portion thereof by means of a drain conduit II which connects to a strong solution return conduit IS. The evaporator E may be of any desired form of construction and is only diagrammatically illustrated herein.

The evaporation of the liquid refrigerant in the inert gas produces rich gas which is discharged from the lefthand end of the conduit ll, as viewed inFigure 1, into the gas heat exchanger G from which it is conveyed by means of a conduit is into the bottom portion of the absorber A.

The upper portion of the absorber A is sup-\ plied with lean absorbent solution from theboiler in a manner to be described more, fully hereinafter. The absorbing solution supplied to the upper portion of the absorber A flows downwardly therethrough by gravity in counterflow relationship with the rich gas flowing upwardLv therethrough. The absorbing solution absorbs refrigerant vapor from the rich gas and the heat of absorption is rejected to cooling air flowing over the exterior walls of the absorbervessel and of the air-cooling fins mounted thereon.

The lean gas thus formed in the absorber is conveyed from the upper portion thereof into the suction eye of the circulating fan Fby means of a conduit 2|. The circulating fan F then places the lean gas under pressure and discharges the same into the gas heat exchanger G through a conduit 22. After traversing the gas heat exchanger the lean gas is supplied to the bottom portion of the evaporator E by means of a conduit 23, thus completing the inert gas circuit.

The lean solution formed-in the boiler by the generation of refrigerant vapor therefrom is conveyed from the boiler to the upper portion of the absorber A by means of the conduit 25, the liquid heat exchanger L, and the conduit 25. After passing through the absorber the resulting rich solution is conveyed from the bottom portion of the absorber to the upper portion of the analyzer D by means of the conduit [8, the liquid heat exchanger L, and the conduit 21.

It is apparent that the upper portion of the absorber is at an elevation appreciably above the liquid level normally maintained in the boileranalyzer system and that some means must be provided to elevate the lean solution from the level of the boiler into the upper portion of the absorber. For this purpose a solution reservoir S is connected to the conduit 26 by means of a short conduit 29.

As is more clearly seen in Figure 2, theupper portion of the reservoir S is provided with an L-shaped extension indicated generally at 30. The L-shaped extension 30 communicates with the upper portion of the reservoir S by means of a conduit 32 which is always in open communication with the reservoirs S and S. The horizontal leg portion 33 of the L-shaped extension 30 of the reservoir S is connected to the suction conduit 2| of the inert gas fan F by means of a conduit 34 which opens into the upper portion of the leg 33. A conduit 35 is connected to the discharge conduit 22 of the circulating fan F and opens into the bottom portion of the extension 33.

A suitable float 31 is mounted in the reservoir S and is connected by means of a link 38 to a snap-acting toggle actuating mechanism 39 which carries a valve plate element 40 on its right-hand end, as viewed in Figure 2, in position to seal one or the other of the

conduits

34 and 35 and thus interrupt communication between such conduits and the reservoirs S and S. Though the apparatus has been shown in considerable detail, it will be appreciated that no attempt has been made in these patent drawings to show exact proportions, as the proportions are matters which will be apparent to those skilled in the art to which this invention relates.

The operation of the apparatus is as follows: When the control mechanism energizes the circulating motor M and the heater for the boiler B in response to a demand for refrigeration, refrigerant vapor is generated from the solution contained in the boiler and a pressure differential of afew inches of water is developed between the conduits 2| and 22 by the circulating fan. Assuming that the apparatus is in the position illustrated in Figures 1 and 2, the reservoirs S and S will be subjected to the discharge pressure of the circulating fan by reason of the fact that the sealing plate ll is out of contact with the conduit 85. As a consequence, the static pressure developed by the circulating fan will be applied to the contents of the reservoirs S and S and will lower the liquid levels therein. As a result of this action the static pressure applied to the reservoir S will discharge liquid refrigerant through the conduit |8 into the evaporator or, more specifically, the box-cooling portion I 8 thereof. The static pressure applied to the reservoir S will lower the level of the contents thereof and will discharge absorption solution through the conduits 29 and 28 into the absorber A.

As the liquid level in the reservoir S drops, the float 31 lowers therewith until it actuates the toggle mechanism 39 which-will snap the sealing plate 40 from contact with the conduit 34 into sealing contact with the conduit 36. The reservoirs S and S" will now be subjected to the suction pressure of the circulating fan F as will the boiler-analyzer, condenser, rectifier system. Under these conditions absorption solution will flow from the boiler into the reservoir S in sufficient quantity to raise the float 31 substantially to the position shown at which time the toggle mechaanism will be actuated back to the position shown and further refrigerant and absorption solution will be discharged into the evaporator and absorber respectively in the manner described heretofore.

It is preferred that the toggle mechanism and the solution reservoirs S and 3' shall be designed in such manner that circulation of absorption solution will take place in small quantities and at The conduit 32 also serves as the usual purge vent to relieve the condenser of non-condensible gases. Such non-condensible products consist principally of very small quantities of inert gas carried over intothe boiler from the absorber by the strong absorbing solution. The

conduits

34 and 35 serve to vent the reservoir assembly S,

and consequently the condenser and reservoir S.

to the inert gas circuit.

In Figure 3 there is illustrated a suitable cabinet 48 which includes an. insulated storage compartment 4!, a lower mechanism compartment 42, and a rear air flue 43. The refrigerating apparatus per se is suitably mounted upon a, frame (not shown) and is inserted into the cabinet as a unit. The evaporator passes through a rear window 44 formed in the rear wall of the storage compartment 4|. As the apparatus is assembled with the cabinet the opening 44 is closed by a,

suitable insulated closure element 45 which is constructed as a unit with the refrigerating ap paratus per se. A As can readily be seen from Figure 3, the refrigerant solution reservoir S is mounted within the insulated window 45 whereby the contents of the reservoir S may not be heated with consequent loss of refrigerant capacity and vaporization of the material liquefied in the condenser.

The boiler-analyzer liquid heat exchanger assembly is encased in a suitable block of insulating material 46 and is positioned in the rear central portion of the compartment 42 with the boiler extending transversely thereof and parallel to the rear wall of the apparatus. Cooling air is admitted to the compartment 42 and vto the bottom portion of the flue 43 and flows upwardly the heat rejecting portions of the apparatus.

It is readily apparent from a perusal of Figures 1 and 3 that the condenser extends to an elevation appreciably below the upper portion of the evaporator and substantially to the lower portion thereof This permits the evaporator to be placed in the very highest portion of the chamber 4| and permits the condenser to be made of adequate size without extending the same above the top wall of the compartment 4!, all of which are highly desirable in systems of this type. Because of the fact that th refrigerant is elevated into the evaporator by the static pressure of the fan, the relative position of the condenser and evaporator may be varied within a wide range without interfering with the operation and normal design of the system. Similar latitude is allowed in the positioning of the absorber and boiler assembly.

If desired, the reservoir S and its connections may be eliminated. In this event the condenser will be positioned above the box-cooling evaporator conduit l5 to provide gravity flow of the refrigerant from the condenser to the conduit. Another variation would be to eliminate the reservoir S and its connections and to provide an evaporator of the type described hereinafter in 7 connection with Figure 4.

Though the apparatus works satisfactorily as 3 described a check valve may be installed in the rich-solution conduit It! to prevent the minor 7 surging which occurs therein when the reservoir S is subjected to the high pressure side of the fan. Such a valve would be installed to'permit now only in the direction of the analyzer.

Referring now to Figure 4, there is disclosed a modified form of the invention. Certain portions of the apparatus illustrated in Figure 4 are identical with corresponding parts described in connection with Figures 1 to 3 and are therefore given the same reference characters primed.

In this form of the invention the evaporator is of the type in which the inert gas is propelled at a high velocity so that it will circulate the liquid refrigerant through the evaporator as the refrigerant is evaporating to produce the refrigerating effect. In this type of evaporator it is customary to supply the liquid refrigerant to the very lowest portion thereof adjacent the point at which the inert gas is supplied to the evaporator. For this purpose the condensate is led from the bottom portion of the condenser C to the bottom portion of the evaporator E adjacent its point of connection with the lean gas supply conduit 23' by means of the

conduits

58 and 5|. The bottom portion of the'evaporator is provided with an overflow and anti-blockage drain indicated at 52 which connects to the strong solution return line l8. While any desired construction of evaporator of the type in which the inert gas circulates the liquid refrigerant may be utilized, a preferred construction is disclosed and claimed in the co-pending application of Curtis C. Coons April 2nd, 1941.

A non-return check valve 59 is inserted in the 4 strong solution return conduit l8 ,and is arover the absorber, rectifier and condenser to cool ranged to permit flow of solution to the analyzer but to prevent return flow of solution from the analyzer conduit into'the bottom'portion of the absorber A. I

The suction conduit 2| of the circulating fan F is connected to the condenser discharge conduit by means of a conduit 5 3 which includes an upstanding inverted U-shaped portion 54 extending appreciably above the level of the bottom portion of the condenser to'prevent flooding of the conduit 53 with condensate. A solenoid valve 55 is also included in the conduit 53. The conduit 58 is connected to the discharge conduit 22 of the circulating fan F by means of a conduit 56 which includes a solenoid valve 51.

The operation of the apparatus is controlled by a suitable thermostatic switch mechanism indicated generally at 58 which isresponsive to the temperature of the evaporator or of the refrigerated space. The thermostatic mechanism 58 will include an electrical switch and it may act directly upon a fuel valve to control the operation of the boiler B or the fuel supply for the heater for the boiler may include a solenoid valve directly under the control of the thermostatic mechanism 58.

Energy is supplied to the apparatus from a pair of electrical conductors 58 and BI. The conductor 80 connects directly to the valve 55 and isconnected to the motor M by means of a conductor 62. The conductor BI is connected to the thermostatic control 58. The thermostatic control 58 is then connected to a motor driven timing device 64 by means of a conductor 65. The other side of the motor is connected to the conductor 65 by means of a conductor 65.

I The exact construction of the timing device 64 is not illustrated or described in detail herein I maintained in closed position and is opened when the solenoid is. energized whereas the valve 55 is of the type which is normally maintained in open position but is moved to-closed position when the solenoid is energized.

The operation of this form of the invention is as follows: When temperature conditions in the evaporator are such as to indicate a demand for refrigeration, the thermostatic mechanism 58 will energize the boiler heater and will complete the circuit between the conductors ,6i and 65. This will energize the circulating motor M and the timing device 64. q The timing device 64 will alternately energize and deenergize the

solenoid valves

55 and 51 at short intervals of time. When the valves are en-' ergized the valve 55 will be moved toclosed position'and the valve 5'! will be moved to open position. Under these conditions the full discharge pressure of the circulating fan F will be applied to the conduit 53 and will be passed back through the conduit 50, condenser C and conduit ii onto the surface of the liquid in the boileranalyzer system. This pressure will cause the liquid to back through the

conduits

25 and 21. However, the check valve 59 will prevent flow of fluids through the conduit 21 and liquid will be forced from the boiler through the conduit 25, the liquid heat exchanger L and the conduit 28' into the absorber A through which it will flow by gravity in counterfiow relationship with rich gas discharged from the evaporator. The operation of the absorber and its possible variations are identical with those mentioned previously in connection with the form of the invention illustrated in Figures 1 to 3.

When the timing device 64 de-energizes the

valves

55 and 51 the valve 51 will move to aaomes tor operates as though it were supplied continuously with liquid refrigerant.

It will be understood that this form of the invention may also be provided with a refrigerant elevating arrangement such as that disclosed in connection with Figures 1 and 2 if it is desired to utilize a gravity type evaporator in place of the forced circulation evaporator disclosed in Figure 4.

Referring now to Figures 5 to 8 there is disclosed a third modification of the invention. Certain portions of the apparatus disclosed in Figure 5 are identical with elements previously described in connection with Figures 1 and 2 and are given the same reference characters double primed. Theupper part of the apparatus illustrated in Figure 5 has not been illustrated in detail as the same may be conventional; it may incorporate the features such as those illustrated in Figure l or those illustrated in connection with Figure 4. If the Figure 1 apparatus is utilized, a conduit corresponding to the conduit 32 of Figure 1 will be connected with either of the vessels 10 or ii in order to subject the liquid refrigerant reservoir alternately to the suction and discharge side of the circulator fan as the reservoir is subjected to one or the other thereof. 1 0n the other hand, if it as is taught in the ,co-pending application of Justice H. Beach, Serial No. 220,204, filed July 20, 1938. g

In this form of the invention the lean solution side of the liquid heat exchanger L" is connected to a pair of reservoirs Iii and H by means closed position and the valve will move to open position whereupon the boiler-analyzer system will be subjected to the suction pressure of the fan and absorption solution will flow into the analyzer by way of conduit it, check valve 58, liquid heat exchanger L and the conduit 21'. This sequence of operation will continue for so long as the control 58 energizes the timing device 54 and the circulating motor M.

Due to the fact that the bottom portion of the conduit 23' of the evaporator is subjected to the discharge pressure of the fan diminished by. the resistance of the lean gas side of the gas exchanger, there will be a column of liquid in the conduit 5! of sufilcient height to balance the pressure differential between the conduits 23' and II whenever the valve 55 is in open position. This will also serve to shield the boiler analyzer con-- denser system from the high pressure prevailing in the conduit 23'. However, when the valve II is closed and the valve 51 is open, the high pressure applied to the conduit 53 will cause a momentary excessive discharge of liquid refrigerant into the bottom portion of the evaporator. This, however, does not materially interfere with the operation 01' the system as the greater'quantity of liquid thus discharged into the evaporator does not tend to circulate therethrough atso rapid a rate and to all practical purposes the evaporaof a conduit 12. Check valves 13 and it are provided in the connections to the reservoirs Iii and ii, respectively. The reservoirs l0 and Ii are each connected to the upper end of the absorber A by means of conduits l8 and 11, respectively.

The condenser is vented by a vent conduit is I to the rich gas conduit I!" to relieve the condenser of non-condensible products.

The reservoirs l0 and Ii are connected by means of conduits 80 and Bi, respectively, to opposite ports II and 84 of a four-ported valve casing 82. The other opposite ports 85 and I! of the casing 82 are connected'to the discharge conduit 22" of the circulating fan by means oi the conduit 81 and to the suction conduit II by means of the conduit 88, respectively. A valve plug I. is mounted within the valve casing 52 and is provided with a pair of valve passageways li and I2.

As is seen in Figures 6 and 7, the valve casing 52 is suspended from the top wall of a housing I! which includes the reservoirs l0 and II. The valve ports I3 and 84 actually open directly into the reservoirs II and ii, respectively, though theerally at N.

float The valve is actuated by means of a mechanism which comprises a curved float arm 95 which is pivotally mounted within the chamber and carries a float 96 on its lower end. The arm 95 is shaped'like a bell crank, as indicated in Figure 8. The short leg of the arm 95 is connected to a snap acting mechanism 91 which engages a pin 98 in a seat on the outer end of itsactuating arm 99. The pin 98 is attached to the valve plug 90 and extends through an arcuate slot H10 in the bottom wall of casing 82 t' will be seen from this that the entire meche anism for operating the valve as well as the valve itself isjsuitably housed within the casing 89 and that the only connections which need be attached to the walls thereof are conduits.

The operation of this form of the invention is as follows: Assume that the float is in the position illustrated in Figure 6, the conduit 81 will be connected to the reservoir ll through the valve port as which will subject the fluid in that reservoir to thedischarge pressure of the fan and will force the liquid through the conduit 11 into the absorber. The check valve 16 prevents the liquid from flowing backwardly through the conduit 12 into the reservoir in and into the boiler-analyzer system. In the meantime liquid is being supplied to the reservoir 10 from the boiler-analyzer assembly and gradually raises' the float 96. When the liquid reaches a predetermined level in the reservoir ID, the

float 96 will actuate the snap acting toggle mechanism s1 and the valve will operate rapidly through an arc of 90 in a counterclockwise direction, as viewed in Figure 7. Under these conditions the

valve ports

83 and 85 will be connected by the valve passageway 9i and the

valve ports

85 and 86 will be connected by the valve passageway 92. The reservoir it will now be subiected to the high pressure side of the fan and liquid will be forced therefrom into the absorber through the conduits i6. whereas the reservoir M will be subjected to the pressure prevailing in the suction conduit 2 i and liquid will flow from the boiler-analyzer system past the check valve it into the reservoir H. The-liquid level in the reservoir 78 will lower sumciently to bring the float substantially to the position indicated in Figure 6 at which time the toggle mechanism will move over center and snap the valve to the position indicated in Figures 6 and 7 whereby the reservoir 7! may again be discharged into the absorber.

This operation continues as long as the control mechanism energizes the circulating fan.

In this form of the invention the flow of the solution into the absorber is to all intents and purposes steady and continuous with only very minor momentary interruptions at the time that the valve operates. The period of operation of the snap mechanism can be suitably regulated if desired by restricting the conduits. l8 and Ti to prevent too rapid a discharge therethrough. This form of the invention is also advantageous because liquid may flow from'the boiler and through the, boiler-analyzer in a substantially continuous stream andis not affected in any way by the reservoirs 1c and H when the same are subjected to the high pressure side of the fan I because of closure of the checlr valves 73 and It will be understood that the reservoirs Ill and II will be designed-with reference to the size of the system withwhich they are to be utilized and that the illustration herein is not drawn to scale, but has been drawn to a scale believed to illustrate best the construction and operation of the apparatus. The reservoirs for domestic units will be small as they will operate frequently and will handle only small quantities of liquid per unit of time.

In accordance with the present invention there is provided a three iluid absorption refrigerating system of the type in which the inert gas is circulated by a pressure differential developed in a portion of its circuit and in which this pressure differential is efllciently utilized to circulate the various liquids which are normally present in the system.

Though the invention has been illustrated and described in appreciable detail, various changes may be made in the construction, arrangement and proportion of parts without departing from the spirit of the invention or the scope of the appended claims. v

1, Absorption refrigerating apparatus comprising an absorber, an evaporator, a condenser and a generator connected in circuit, means for creating and maintaining a pressure difierential in an inert gas circuit and for circulating the inert gas between said absorber and said evaporator, and means for intermittently subjecting other portions of said apparatus to such pressure differential to propel liquids therethrough.

2. Absorption refrigerating apparatus comprising an absorber, anevaporator, a condenser and a generator connected in circuit, a power driven circulator for circulating inert gas-through a circuit including said absorber and said evaporator,

- and means for alternately subjecting a portion of a solution circuit including said absorber and said generator to the suction and discharge sides of said circulator to circulate absorption solution therethrough.

3. Absorption refrigerating apparatus comprising an absorber, an evaporator, a condenser and a generator connected in circuit; said condenser extending downwardly below the upper portion of said evaporator, a power driven circulator for circulating inert gas through. a circuit including said evaporator and said absorber, means for conveylng refrigerant liquid upwardly from the discharge portion of said condenser to the upper' portion of said evaporator, and means for alterferential'in said inert gas circuit to propel the nately applying the inlet and outlet pressures of said circulator to said last mentioned means to elevate liquid refrigerant into said evaporator.

4. Absorption refrigerating apparatus compris-L ing an inert gas circuit including an evaporator and an absorber, a solution circuit including a generator and said absorber, means for liquefying refrigerant vapor produced in said generator and for supplying-the liquid to said evaporator, means for creating and sustaining a pressure difinert gas the'rethrough, a reservoir in said solution circuit, and means for alternately connecting said reservoir tohigh and low pressure areas of said inert gas circuit to propel solution through said solution circuit. 1

5. Absorption refrigerating apparatus comprising an inert gas circuit including an evaporator and an absorber, a solution circuit including a generator and said absorber, means for liqueiying refrigerant vapor producedin said generator and for supplying the liquid to said evaporator,

means for creating and sustaining a pressure differential in said inert g s circuit to propel the inert gas therethrough, a reservoir insaid solution circuit, means for alternately connecting said reservoir to high and low pressure areas of said inert gas circuit to propel solution through said solution circuit, and a check valve in a portion of said solution circuit to permit flow of solution thereby only .in a given direction.

6. Absorption refrigerating apparatus comprising an inert gas circuit including an evaporator and an absorber, a solution circuit including a generator and said absorber, means for liquefying refrigerant vapor produced in said generator and for supplying the liquid to said evaporator, means for maintaining a substantially steady constant pressure differential in said inert gas circuit to propel the inert gas therethrough, a reservoir. in said solution circuit, means connecting said reservoir to high and low pressure areas of said inert gas circuit, and means responsive to the level of the solution in said reservoir for controlling the communication between said reservoir and said connecting means.

7. Absorption refrigerating apparatus comprising an inert gas circuit including an evaporator and an absorber, a solution circuit including a generator and said absorber, means for liquefying refrigerant vapor produced in said generator and forsupplying the liquid to said evaporator, means for creating apressure differential in said inert gas circuit to propel the inert gas therethrough, and means for alternately applying the pressure prevailing in high and low pressure areas of said inert gas circuit to said generator and said condenser to circulate liquids through portions of said apparatus.

8. Absorption refrigerating apparatus comprising a cabinet including an insulated storage chamber, a mechanism compartment, an inert gas circuit including an evaporator in said chamber and an absorber in said compartment, an absorption liquid circuit including a generator in said compartment and said absorber, means for creating a pressure differential in said inert gas circuit to propel inert gas therethrough, means for liquefying refrigerant vapor produced in said generator and for supplying the liquid to said evaporator, a reservoir embedded in the insulation of said chamber and communicating with a portion of the apparatus normally containing liquid, and means for periodically subjecting said reservoir to the effects of a high pressure area of said inert gas circuit to circulate liquid through that portion of the apparatus which is connected to said reservoir.

9. Absorption refrigerating apparatus comprising a cabinet including an insulated storage chamber, a mechanism compartment, an inert gas circuit including an evaporator in said chamber and an absorber in said compartment, an absorption liquid circuit including a generator in said compartment and said absorber, means for creating a pressure differential in said inert gas circuit to propel inert gas therethrough, a condenser in said compartment extending to an elevation below the upper portion of saidev'aporator and connected to receive refrigerant vapor from said generator, means for conveying refrigerant liquid from said condenser to said evaporator, a reservoir embedded in the insulationv of said chamber and communicating with said liquid refrigerant conveying means, and means for periodically subjecting said reservoir to the effects of a high pressure area of said inert gas circuit to circulate liquid refrigerant from said condenser to said evaporator.

. 10. Absorption refrigerating apparatus comprising an inert gas circuit including an evapmeans, a float operated by changes in the liquid level in said reservoir for actuating said snapacting means.

11. Absorption refrigerating apparatus comprising an inert gas circuit including an evaporator and an absorber, a solution circuit including a generator and said absorber, means for liquefying refrigerant vapor produced in said generator and for supplying the liquid to said evaporator, means for creating a pressure differential in said, inert gas circuit to propel the inert gas therethrough, .a control chamber including a plurality of reservoirs and a control valve, means in said solution circuit, means connecting said valve means to high and low pressure areas of said inert gas circuit, said valve means being constructed and arranged to provide communication between each of said reservoirs and said connecting means serially whereby each reservoir is altematelysubjected to high and low pressures, means providing each of said reservoirs with one way flow inlet connections, a discharge connection to each of said reservoirs, and means for actuating said valve means.

12. Absorption refrigerating apparatus comprising an inert gas circuit including an evaporator and an absorber, a solution circuit including a generator and said absorber, means for liquefying refrigerant vapor produced in said generator and for supplying the liquid to said evaporator, electrically operated means for creating a pressure differential in said inert gas circuit to propel the inert gas therethrough, means for alternately applying the pressure prevailing in highand low pressure areas of said inert gas circuit to said generator and said condenser to circulate liquids through portions of said apparatus, said last mentioned means including solenoid valves in control of ,said high and low pressure connections, electrically operated means in control of said valves, and refrigeration demand responsive means in control of both of said electricallyoperated means.

13. That method of circulating liquids in absorption refrigerating systems of the type utilizing a refrigerant, an absorbent and a pressure equalizing medium inert with respect to the refrigerant and the absorbent which includes the steps of circulating the pressure equalizing medium between a refrigerating zone in which vapor is added thereto and an absorbing zone in which vapor is removed therefrom, circulating the absorbe'nt between a generating zone in which reof heat to the solution, liquefying the refrigerant vapor, producing a refrigerating effect byprising an absorber, an evaporator, a condenser evaporating the refrigerant liquid into a pressure tently transferring bodies of solution into contact with said mixture by applying thereto the static pressure of an area of the system norand a generator connected in circuit, a' power driven circulator for circulating inert gas through a circuit including said absorber and said evaporator, and means for alternately connecting a liquid containing portion of said apparatus to v the suction and discharge sides of said circulator to circulate liquid through said portion mally maintained at a higher static pressure than the area of the system in which the solution contacts said mixture. l5. Absorption refrigerating apparatus comprising an inert gas circuit including an evaporator and an absorber, a solution circuit including a generator and said absorber, means for liquefyingrefrigerantvapor produced in said generator and for supplying the liquid to said evaporator. means for continuously maintaining a portion of said apparatus at a pressure higher than that normally prevailing in said solution circuit, and means for intermittently subjecting a portion of said solution circuit to the pressure prevailing in saidhigh pressure portion of said apparatus to cause the solution to flow from said first mentioned part of said solution circuit to another part thereof.

16. Absorption refrigerating apparatus comof said apparatus.

17. Absorption refrigerating apparatus comprising a generator, an absorber having a liquid inlet above said generator, an evaporator, a condenser connected to receive refrigerant vapor from said generator and to supply refrigerant liquid to said evaporator, means including a powerdriven circulator for circulating an inert gas through said evaporator and said absorber, said absorber being connected to the suction side of said circulator, means forming a connection including a U-shaped part for conducting absorption solution from said generator to said absorber liquid inlet, means for conveying absorption solotion from said absorber to said generator, and means for intermittently subjecting the surface 1 of the absorption solution in said U-shaped part remote-from said absorber inlet to the discharge pressure of said circulator to displace the absorption solution through said U-shaped part into said absorber.

- ARNOLD D. SIEDLE. A