US2345505A - Refrigeration - Google Patents

Description

March 28, 1944. 1 A n E LE 2,345,505

REFRIGERATION Filed April 6, 1940 2 Sheets-Shet 1 '/e H l INVENTOR Z9 1 fb 'nqlzsiY 0. 8iedle- ATTORNEY A. D. S IEDLE REFRIGERATION Filed April 6, 1940 2 Sheets-Sheet 2 r. ,1 II I Arnold 0f. Siedle WZY ATTORNEY INVENTOR Patented Mar. 2 8, 1 944 REFRIGERATION Arnold D. Siedle, Canton, Ohio, assignor to The Hoover Company, North Canton, Ohio Application April 6, 1940, Serial No. 328,197 21 Claims. (Cl. 62-5) This application relates to the art of absorption refrigerating machines and particularly to absorption refrigerating machines including a plurality of evaporating elements which operate at different temperature levels.

In absorption refrigeratin machines of the three-fluid type the inert gas refrigerant vapor mixture which is discharged from the evaporator is normally at a low temperature and is thus inherently capable of producing a useful refrig crating effect aside from cooling the inert gas enroute to the evaporator if such cold mixture can be properly introduced into a cooling chamher to achieve such efiect.

A material difiiculty encountered in prior systems results from the fact that adequate control over the high temperature or food storage refrigerating element is diflicult to obtain due to difficulties encountered in attempts to supply an adequate quantity of liquid refrigerant for maintaining the temperature within the high temperature compartment within safe refrigerating limits while not supplying refrigerant in a quantity sufllcient to cause undesirably low temperatures in the evaporator for such compartment and without causing such evaporator to collect frost. It is also difficult tocontrol the machine due to the provision of a plurality of evaporators as it occasionally occurs that the low temperature or ice freezing demand will be met but the high temperature or food storage section of the machine will demand refrigeration or vice versa. Another difficulty sometimes encountered in prior inachines results from the fact that the very cold inert gas refrigerant vapor mixture discharging from the ice-freezing portion of the machine into the food storage evaporator will be sufficiently low in temperature and will cool the evaporator sufficiently to cause the same to collect frost with resulting deleterious effects.

Accordingly, it is a principal object of the present invention to provide a three-fluid absorption refrigerating machine which is provided'with a V plurality of separate cooling units so arranged that the low temperature or ice-freezing unit thereof will operate to produce ice freezing temperatures in a low temperature refrigerating compartment and in which the high temperature or food refrigerating section of the evaporator of the machine will operate at temperatures above the freezing point of ice and will function to produce temperatures safe for food preservation but which will not operate at a temperature sufficient to cause deposition of frost with resulting deleterious drying of foodstuffs.

It is a further object of the present invention to provide a three-fluid refrigerating system having a plurality of cooling units in which the cold products discharged from a low temperature cooling unit are supplied to produce the primary refrigerating capacity of a higher temperature refrlgerating unit and in which means are provided to prevent the low temperature gases from reaching the high temperature refrigerating unit at a temperature sufficiently low to cause deposition of frost upon such high temperature unit.

It is another object of the present invention to provide an absorption refrigerating machine having a plurality of cooling units which normally operate at different temperature levels, in which the high temperature cooling unit is normally chilled by cold products discharged from the low temperature unit and in which provision is made for the supply of liquid refrigerant directly to the high temperature unit only in the event that V the temperature conditions prevailing in the high temperature unit necessitates such action and in an amount only sufficient to maintain safe food preserving temperatures.

It is a further object of the present invention to providea three-fluid absorption refrigerating machine having high and low temperature refrigcrating sections in which control means are provided whereby normal control of the machine is achieved in response to temperature conditions in the low temperature compartment, and in which an adjusting means is provided for varying the low temperature chamber refrigerating conditions, and in which such machine is fur ther provided with a control mechanism which will supersede the normal-.control to produce refrigeration for food storage. purposes only in the event that such operation of the machine becomes necessary.

Other objects and advantages of the invention will be apparent as the description proceeds when taken in connection with the'accompanying drawings, in which:

Figure 1 is a diagrammatic representation of a refrigerating system embodying the present in vention and including certain parts in perspective associated with portions of a cabinet which is shown in section;

Figure 2 is a transverse sectional elevational view of the refrigerating system of Figure 1 illustrating the arrangement of the various parts thereof in connection with the cabinet of a. do-

mestic refrigerating machine.

Refening now to the drawings in detail and first to Figure 1 thereof. there'is illustrated a three-fluid absorption refrigerating machine more detail hereinafter.

The above described refrigerating system will be charged with a suitable refrigerant such as ammonia, an absorbent therefor, such as water, and an inert pressure equalizing medium, preferably a dense gas like nitrogen.

The boiler B is heated in any desired manner as by a gaseous fuel burner H which is supplied with fuel and controlled in a manner to be de scribed hereinafter.

The application of heat to the boiler B liberates refrigerant vapor from the strong solution normally therein contained. The vapor so liberated passes upwardly through the analyzer D and is conveyed therefrom by the conduit H which includes the rectifier R to the upper portion of the condenser C.

The lean solution formed in the boiler by the generation of refrigerant vapor is conveyed therefrom to the solution reservoir S by way of the conduit I2, the liquid heat exchanger L, and

the looped finned pre-cooling conduit l3. The

upper portion of the reservoir S is vented by means of a conduit It to the suction conduit of the fan F whereby the pressure prevailing in the reservoir is the suction pressure of the fan. The solution in the reservoir is conveyed therefrom by means of the conduit l5 which discharges into the suction conduit I5 adjacent its point of connection to the upper end of'the absorber A. The conduit I6 is a gas lift pumping conduit and pumping gas is supplied thereto by means of a conduit H which is connected between the discharge conduit it of the circulating fan F and the conduit l5 below the liquid level normally prevailing therein whereby the lean solution is elevated into the upper end of the absorber by gas lift action.

Lean solution flows downwardly through the absorber by gravity in counterflow relationship to a rich mixture of pressure equalizing medium and refrigerant vapor which is flowing upwardly therethrough. The source of this-mixture will be described hereinafter. The lean solution absorbs refrigerant vapor from the gaseous mixture flowing through the absorber and the resulting heat of absorption is rejected to cooling air flowing over the exterior walls of the absorber conduits and the fins attached thereto. The strong solution thus formed in the absorber is conveyed from the bottom portion thereof to the upper portion of the analyzer D by way of the conduit l9, the liquid heat exchanger L and the conduit 20. The strong solution then flows downwardly through the analyzer to the boiler in counterilow relationship to the vapors flowing upwardly through the analyzer, thus completing the absorbing solution circuit.

The lean gas which is formed in the absorber by the absorption of refrigerant vapor exits from the upper portion thereof into the circulating fan E by way of the conduit i5. The gas is placed under a few inches of water pressure in the fan F-from which it is conveyed to the evaporatar E by way of the conduit l8, the outer path of the heat exchanger G, the conduit 22, the outer path of the heat exchanger G, and the evaporator gas supplyconduit 23.

The evaporator E comprises a'lower horizontal pipe coil 25 which is serially connected to a substantially identical superposed plane horizontal coil 26 by means of a riser conduit 21. The inert gas supply conduit 23 joins the end of the coil 25 opposite to thatwhich is connected to the riser conduit 21.

The refrigerant vapor which is supplied to the upper portion of the condenser C is liquefied therein by heat exchange with atmospheric air. The liquid so formed in the condenser discharges to the bottom portion thereof through a conduit- 28 into a suitable refrigerant collecting chamber 29. Liquid refrigerant is drained from approximately the mid portion of the chamber 29 into the coil 25 adjacent its point of connection with the gas supply conduit 23 by means of a suitable U-shaped liquid sealing and pressure balancing column conduit 30.

The conduits forming the evaporator E are of relatively small diameter with respect to the quantity of gas to be circulated therethrough wherefore the inert gas flows through the evaporator E with a velocity sufiicient to sweep or drag the liquid refrigerant therethrough by the fric tional drag of the inert gas stream. Consequently, the inert'gas serves to circulate the liquid refrigerant through the evaporator E as the liquid is evaporating into the gas stream. After traversing the evaporator E the resulting partially enriched inert gas is conveyed therefrom to the evaporator E by means of the conduit 3| which connects to one end of the coil 26, the inner path of thegas heat exchanger G and the con- 4o duit 32.

from the highest fan pressure prevailing in the system.

A drain conduit 35 is connected between the top side of a portion of the bottom coil 25 of the evaporator E and the rich gas side of the gas heat exchanger G. The function of the conduit 35 is not to drain the evaporator but to prevent liquid from accumulating in the coil 25 to a depth sufllcient to prevent inert gas flow therethrough.

The inert gas which is supplied to the conduit 32 base low temperature because it comes directly from a low temperature evaporator. This gas is'partly heated in the gas heat exchanger G and it is preferable so to design the apparatus that the inert gas refrigerant vapor mixture flowing through the conduit 32 will have a temperature at or slightly above 32 F. whereby the evaporator E will not collect frost.

As is readily seen from Figure l the evaporator E consists simply of a substantially horizontal looped coil to which the oonduit 32 is connected.

The evaporator E like the evaporator E above described is constructed of tubing which is. so selected with respect. to the quantity of inert gas circulated per unit of time that the inert gas r 2,846,505 flows through the evaporator E with a velocity of the tubular inclined absorber A by way of the conduit 31., the inner path of-the gas heat exchanger G and the conduit 36. The inert gas then flows upwardly through the absorber as its refrigerant vapor content is absorbed in the manner heretofore described, thus completing the inert gas circuit.

During normal operation of the system the cold gas flowing through the evaporator E will suflice to maintain adequate temperature conditions therein.

The chamber 66 is interiorly divided by an imperforate thermostatic disc 45 into an upper inert gas chamber 69 to which the evaporator E and the conduit 31 are connected and a lower 'valve chamber 46. The bottom portion of the ing from the evaporator E reach a temperature of 45 F., for example. This action admits liquid refrigerant from the vessel 29 to the gas inlet side of the evaporator E.

The evaporator E is purged by blowing excess material and non-volatile material through the conduit 3| into the gas heat exchanger G from which such material is then conveyed by the inert gas stream through the evaporator E, the chamber 36, the conduit 61, and the inner path of the gas heat exchanger G. Such material then flows by gravity through the conduit 38 and then into the conduit l9 and is thereby returned tothe absorbing solution circuit.

Referring now to Figures 1 and 2, the arrangement of the parts with respect to the cabinet 50 will be described. The cabinet 50 includes an upper insulated low temperature freezing compartment which houses the evaporator E and is closed by a suitable closure element 52. An insulated wall 56 which may be integral with the walls of the cabinet or separate therefrom, as desired, separates the freezing chamber 5| from a food storage and refrigerating chamber 54 which houses the evaporator E. and is closed by a suitable closure element 55. An air-cooling and mechanism compartment 56 extends beneath'the insulated chamber 54 and along the rear wallof the cabinet construction.

The entire apparatus rests 'on a suitable foot member 51 which is' arranged to allow free access of cooling air into the compartment 56. The boiler-analyzer liquid heat exchanger assembly 'is housed within an insulating .block 56 which rests directly upon the foot member 51. The abfrom a position beneath the vertically extending air flue portion of the chamber 56.

The rectifier R is approximately midway of the height of the cabinet in the vertically extending portion of the chamber 56 and the condenser C is inclined, across the vertical portions of the chamber 56 to the top thereof. The refrigerant reservoir 29 as illustrated is positioned just beneath the condenser in the air flue. However, this element may be within the freezing compartment 5| or it may be embedded inthe insulation thereof as desired.

The compartments 5| and 54 are each provided on the rear wall thereof with openings 66 and 6|, respectively, which are the size to permit the evaporators E and E, respectively, to be inserted into the chambers 5| and 54, respectively. The refrigerating mechanism carries insulated closure elements 63 and 64 which are designed to fit into and close the openings 6.0 and 6|, respectively. The closure elwnents 66 and 64 are sealed by suitable gaskets 65.

The gas heat exchangers G and G are partially embedded, as is illustrated, in the insulation of the rear walls of the chambers 5| and 54.

The evaporator coils 25 and 26 of the evaporator E are each overlaid by a suitable sheet metal plate 61 which is adapted'to support footstufls or freezing receptacles such as the ice trays 66. If desired, a suitable foodstufis receptacle 69 may be positioned in the bottom portion of the chamber 5| to rest upon the insulated partition 53.

As is shown in Figure 2 the evaporator coils E preferably provided with air-cooling fins 62 in order to increase the heat transfer between this element and the air within the chamber '54.

Fuel is supplied to the heater H through a gas supply conduit 10 which includes a solenoid control valve H. A suitable by-pass 12 is provided around the valve II in order to maintain a small igniting or pilot flame on the burner H which will include any desired type of flame failure safety 1 cut-off mechanism.

Electrical energy is supplied from a pair of conductors I4 and 15. The conductors 15 connects directly to the solenoid valve II and is connected to the motor M by means of a conductor 16. The conductor 14 connects directly to the stationary terminal 11 of a switching mechanism to be described hereinafter. The other terminal 16 of the switching mechanism is connected to the solenoid valve H by a conductor 16 and the conductor 19 is connected to the motor M by means of a conductor 60. Thus, when an electrical circuit is made between the conductors l4 and 16 the motor will be energized and the solenoid valve will be urged to openposition to provide a full or operating flame upon the burner H.

-The control mechanism comprises a control housing 6| which carries the terminals I1 and 16. The terminal or contact 11 is arranged to be contacted by a movable contactor 62 which is carried by a toggle switching mechanism 66 and is connected bymeans of afiexible conductor 64 to the terminal 16. Y

The toggle mechanism plunger 65 which is carried in a suitable journal 66 formed on the wall of the casing 66. The plunger 65 is urged to the left, as viewed in Figure 2, by means of a spring 61 which re-acts tween the support 66 and an enlarged plate 66 which is carried upon the left hand end of the plunger 65.

The plate 66 is arranged to be contacted by a pair of contact fingers 66 and 66 which are car- 66 is actuated by a from the end thereof carrying the actuating fingers 99 and 90 are rigidly secured to the housing 3| in a known manner.

The bellows 92 is arranged to respond to the thermal condition of the evaporator 'coil E adjacent its point of connection with the chamber 33 by means of a capillary conduit 93 and a bulb element 94 which rests on the evaporated coil E.

The bellows 9| is arranged to respond to the temperature of the evaporator E by means of a capillary conduit 95 and a bulb 96 which is preferably placed in contact with the evaporator E.

The free end of the bellows 9| carries a projecting guide arm 91 which is slidably received in a smooth bore 98 of an adjusting nut element 99. The element 99 may be secured against rotation by a projection in the housing 3|, by making the plunger 91 and bore 98 non-circular or in any other desired manner. The end of the nut element 99 remote from the bellows 9| is internally threaded to threadedly receive an adjusting screw I rotatably mounted at IOI in the end wall of the chamber 3| remote from the bellows 9|. The end of the adjusting shaft I00 which projects through the wall of the chamber 8| carries a pulley element I02 which is adapted to be rotated by' a suitable cable I03.

It will be understood that the chamber 3| may be located in any portion,of the compartment 55 and that a suitable adjusting dial and pulley mechanism will be mounted either in the chamber 5| or on the exterior of the cabinet 50 and will be arranged to actuate the cable I03 to turn the adjustable screw I00.

be opened by the thermostatic disc 45 and liquid refrigerant will be supplied directly to the evaporator E until such time as the gases discharging therefrom have been lowered in temperature below 45 degrees Fahrenheit.

When the valve 43 is in open position liquid refrigerant will be supplied to the evaporator E in preference to the evaporator E, as it is desirable that foodstuffs shall be preserved at the expense of ice production if such operation becomes necessary.

A compression adjusting spring I04 surrounds the plunger 91 and bears at one end against the free end of the bellows 9| and at its opposite end against a suitable spring retaining cup I05 which bears against the adjusting nut 99. Consequently, rotation of the adjusting screw I00 will vary the compression on the spring I04 which will thereby vary. the force against which the bellows 9 I must expand to operate the toggle switching mechanism 83. Thus the temperature maintaind in the compartment E will depend upon the compression of spring I04 which will be determined by a suitable adjusting mechanism.

Theoperation of the invention is as follows: During normal operation of the system, the great est load will occur in the chamber 5| and the apparatus will normally regulate itself to maintain the chamber 5| within the temperature limits for which the control mechanism is set which will be at a temperature such as to produce ice in suitable ice trays so the rate at which ice is produced will, of course, depend upon the setting of the control mechanism.

The gases discharged from the evaporator E are wary cold and they are partially heated in the 'gas heating chamber G after which they discharge into the evaporator E thus producing refrigeration in the chamber 54 at temperatureswhich are safe for preservation of food stuffsbut which will not cause deposition of frost on the evaporator E. Normally the cold gases flowing throuh the evaporator E will contain ample capacity to refrigerate the compartment 54. However, in the event that suchis not the case and the temperature of the gases discharged into the chamber 30 exceeds, for example, a temperature' of 45 degrees Fahrenheit, the valve 43 will Normally the control of the system will be exercised by the bellows 9| as the demand for refrigeration in the compartment 5| will normally insure ample refrigeratingefiect in the com-. partment 54 due to the cold gases and occasional supplies of liquid refrigerant through the valve 43. However, if the temperature of the gases in the chamber 39 should exceed, for example the value-of 48 degrees Fahrenheit, the bellows 92 will expand, thus shifting the plunger 85 .to the right, as viewed in Figure 2, which will shift the toggle switch to the closed circuit position and will thus energize the system regardless of the condition of the thermostatic bellows 9|; that is, under certain conditions of refrigeration demand, the bellows 92 will supersede the control of the bellows 9|. Obviously, when a condition is reached which would cause the bellows 92 to take over the control of the refrigerating mechanism, the valve 43 will be in open position and any liquid refrigerant produced by the condenser C will discharge directly into the evaporator E rather than into the evaporator E which condition will prevail until the temperature within the compartment 54 has been brought within safe refrigerating limits. The bellows 92 will probably operate .very infrequently. and for many types of installation it may be eliminated entirely as-the cold gases discharged into the evaporator E and the occasional supplies of liquid refrigerant through the valve 43 will adequately satisfy the refrigerating demands.

It is particularly to be noted that the adjustment operates only upon the bellows 9| as the bellows 92 will-be set for some refrigerating temperature such as, for example 48 degrees Fahrenheit which will'insure operation of the system when the temperature within the compartment 54 approaches the danger zone in order to take over the normal control exercised by the bellows 9|. 'However, it is neither necessary or desirable to provide for temperature variation within the compartment 54, consequently no adjustment is provided for the bellows 92.

Thus, in. accordance with the present invention, a three-fluid absorption refrigerating machine is provided in which low temperature refrigerating needs are met by direct evaporation of liquid refrigerant into an inert gas, food storage or higher temperature refrigeration needs are met by the refrigerating capacity of the cold gases discharged from the low temperature evaporator. Abnormal high temperature refrigeration demands are met by diverting the liquid refrigerant from the low temperature evaporator to the food storage evaporator when a pre-determined temperature condition exists and a further factor of safety is provided by incorporating a control mechanism which will supersede the normal conperature within the high temperature or food storage compartment exceeds a pre-determined maximum value.

While the invention has been illustrated and described herein in considerable detail, it is not to be construed as being limited to the precise construction and arrangement illustrated as various changes may be made in the construction, arrangement, proportion of parts without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. That improvement in refrigerating systems of the type in which refrigerant vapor is expelled from solution in an absorbent by the application of heat, the expelled vapor is converted to a liquid by the extraction of. heat, the liquid is vaporized into an inert gas to'produce a refrigcrating effect and the refrigerant vapor is -removed from the inert gas by contacting the inert gas refrigerant vapor mixture with absorbent solution from which refrigerant vapor has previously been expelled which includes the steps of evaporating said refrigerant liquid into said inert gas in a first refrigerating zone and then utilizing the resulting cold inert gas refrigerant vapor mixture to cool a second refrigerating zone, supplying the liquid refrigerant to said second refrigerating zone for evaporation therein whenever the temperature of such zone exceeds a predetermined value, and governing the expulsion of refrigerant vapor in accordance with the refrigerating demand of said second refrigerating zone.

2. That improvement in refrigerating systems of the type in which refrigerant vapor is expelled from solution in an absorbent by the ap plication of heat, the expelled vapor is converted to a liquid by the extraction of heat, the liquid is vaporized into an inert gas to produce a refrigerating effect and the refrigerant vapor is removed from the inert gas by contacting the inert gas refrigerant vapor mixture with absorbent solution from which refrigerant vapor has previously been expelled which includes the steps of evaporating said refrigerant liquid into said inert gas in a first refrigerating zone and thenutilizing the resulting cold inert gas refrigerant vapor mixture to cool a second refrigerating zone, supplying the liquid refrigerant to said second refrigerating zone for evaporation therein whenever the temperature of such zone exceeds a predetermined value, governing the expulsion of re-- frigerant vapor in accordance with the refrigerating demand of said second refrigerating zone, and superseding the governing of refrigerant vapor expulsion by the refrigerating demand in said second refrigerating zone upon the occurrence of a predetermined relationship between the refrigerating demand prevailing in said first and second refrigerating zones.

3. That improvement in refrigerating systems of the type in which refrigerant vapor is expelled from solution in an absorbent by the application of heat, the expelled vapor is converted to a liquid by the extraction of heat, the liquid is vaporized into an inert gas to produce a refrigerating effect and the refrigerant vapor is removed from the inert gas by contacting the inert gas refrigerant vapor mixture with absorbent solution from which refrigerant vapor has previously been expelled which includes the steps of evaporating said refrigerant liquid into said inert gas in a first refrigerating zone, utilizing the resulting cold inert gas refrigerant vapor mixture to cool a second refrigerating zone, and directing said refrigerant liquid away from said first refrigerating zone to said second refrigerating zone in response to a predetermined condition in said second refrigerating zone.

4. A refrigerating device comprising a cabinet construction including a storage compartment having high and low temperature chambers, and a mechanism compartment arranged for flow of cooling air therethrough, a cooling unit in each of said chambers, a generator and an aircooled condenser in said mechanism compartment connected to receive refrigerant vapor from said generator, an air-cooled absorber in said mechanism compartment connected with said generator toform a solution circuit, and also connected with said cooling units to form an inert gas circuit, means'for supplying refrigerant liquid produced in said condenser to the cooling unit in said low temperature chamber, and means responsive to the condition of the inert gas in the cooling unit in said high temperature chamber for governing the admission of liquid refrigerant to the cooling unit in said high temperature chamber. Y

5. A refrigerating device comprising a cabinet' construction including a storage compartment having high and low temperature chambers, and

I a mechanism compartment arranged for flow of cooling air therethrough, a cooling unit in each of said chambers, a generator and an air-cooled condenser in said mechanism compartment connected to receive refrigerant vapor from said generator, an air-cooled absorber in said mechanism compartment connected withsaid generator to form a solution circuit and also connected with said cooling units to form an inert gas circuit, said inert gas circuit being so arranged that the inert gas flows through the cooling unit in said low temperature chamber, then through the cool-- ing unit in said high temperature chamber and then through said absorber, means for supplying liquid refrigerant from said condenser to the cooling unit in said low temperature chamber, means for diverting th liquid refrigerant produced in said condenser to said high temperature chamber cooling unit upon the occurrence of a predetermined condition, means for controlling the production of refrigerant vapor by said generator, means responsive to the refrigerating demand of said low temperature chamber for actuating said vapor production control means, and means responsive to a predetermined condition in said high temperature chamber for actuating said vapor production control means.

6. A refrigerating device comprising a cabinet construction including a storage compartment having high and low temperature chambers, and a mechanism compartment arranged for flow of cooling air therethrough, acooling unit in each of said chambers, a generator and an air-cooled condenser in said mechanism compartment con, nected to receive refrigerant vapor from said generator, an air-cooled absorber in said mechanism compartment connected with said generator to form a solution circuit and also connected with said cooling units to form an inert gas circuit, said inert gas circuit being so arranged that the inert gas flows through the cooling unitin said low temperature chamber, then through the cooling unit in said high temperature chamber and then through said absorber, means for'supplying liquid refrigerant from said condenser to the cooling unit in said low means for diverting the liquid refrigerant produced in said condenser to said high temperature temperature chamber.

temperature of said second cooling unit for di-- verting said refrigerant medium to said second cooling unit, first refrigerating demand responsive means for governing the production of refrigerant medium in response to the condition of said first cooling unit, means for adjusting said first refrigerating demand responsive means to alter the refrigerating effect produced in said first cooling unit, and a second refrigerating demand responsive means responsive to the condition of said second cooling unit for taking over control of the refrigerant medium production from said first refrigerating demand responsive means. 8. A refrigerating mechanism comprising a first cooling unit, a second cooling unit connected to receive vapors discharging from said first cooling unit, means for producing liquid refrigerant, means for supplying liquid'refrigerant from said liquid refrigerant producing means to said first cooling unit, and means responsive to the thermal condition of the vapors discharging from said second cooling unit for diverting liquid refrigerant produced by said liquid refrigerant supply means from said first cooling unit to said second cooling unit.

9. A refrigerating mechanism comprising a first cooling unit, a second cooling unit connected to receive vapors discharging from said first cooling unit, means for producing liquid refrigerant, a collecting vessel connected to receive said liquid, means connected to said vessel above the bottom thereof for conveying liquid from said vessel to said first cooling unit, means connected to said vessel below said means for conveying liquid to said first cooling unit for conveying liquid to said second' cooling unit, a valve controlling said means for conveying liquidto said second cooling unit, and means responsive to a condition of the vapors flowing through said second cooling unit for controlling the operation of said valve.

10. An absorption refrigerating system comprising a high temperature evaporator, a low temperature evaporator, an absorber, means connectinging said evaporators and said absorber to form an inert gas circuit so constructed and arranged that inert gas discharged from said absorber flows through said low temperature evaporator, then through said high temperature evaporator and then returns to said absorber, a generator connected to said absorber to form a solution circuit, means for liquefying refrigerant vapor produced in said generator and for supplying the resulting liquid to said low temperature evaporator, and means responsive to the temperature of products discharging from said high temperature evaporator for diverting liquid refrigerant from said low temperature evaporator to said high temperature evaporator when the temperature of said products exceeds a predetermined value when the temperature ofsaid second evaporator exceeds a first predetermined temperature and for preventing such diversion when the temperature of said second evaporator reaches a second predetermined low temperature which is above the freezing temperature of water.

11. An absorption refrigerating system comprising a high temperature evaporator, a low temperature evaporator, an absorber, means connecting said evaporators and said abosrber to form an inert gas circuit so constructed and arranged that inert gas discharged from said absorber fiows through said low temperature evaporator, then through said high temperature evaporatorand then returns to said absorber, a generator connected to said absorber to form a solution circuit, means for liquefying refrigerant vapor produced in said generator and for supplying the resulting liquid to said low temperature evaporator, means responsive to the temperature of products discharging from said high temperature evaporator for diverting liquid refrigerant from said low temperature evaporator to said high temperature evaporator when the temperature of said products exceeds a predetermined value, and means normally arranged to govern the production. of refrigerant vapor by said generator in response to the temperature of said low temperature evaporator and including means for shifting such control to be responsive to the temperature of said high temperature evaporator when ever the temperature of said high temperature evaporator exceeds a pre-selected value.

12. An absorption refrigerating system' comprising a high temperature evaporator, a low temperature evaporator, an absorberjneans connecting said evaporators and said absorber to form an inert gas circuit so constructed and arranged that inert gas discharged from said absorber flows through said low temperature evaporator, then through said high temperature evaporator and then' returns to said absorber, a generator connected to said absorber to form a solution circuit, means for liquefying refrigerant vapor produced in said generator and for supplying the resulting liquid to said low temperature evaporator, means responsive to the temperature of products discharging from said high temperature evaporator for diverting liquid refrigerant from said low temperature evaporator to said high temperature evaporator when the temperature of said products exceeds a predetermined value, and means normally arranged to govern the production of refrigerant vapor by said generator in response to the temperature of said low temperature evaporator, means for selectively regulating the operation of said last mentioned temperature responsive means to regulate the temperature of said low temperature evaporator, and means for shifting the control of refrigerant production to be responsive to the temperature ofsaid high temperature evaporator independently of the condition of said regulating means whenever the temperature of said high temperature evaporator exmedium being so arranged that refrigerant vapor produced in said first evaporator and pressure equalizing medium cooled in said first evaporator fiow through said second evaporator, and means for diverting refrigerant liquid from said first evaporator to said second evaporator when the temperature of said second evaporator exceeds a first predetermined temperature and for preventing such' diversion when the temperature of said second evaporator reaches a second predetermined low temperature which is above the freezing temperature of water.

14. In a refrigerating apparatus a cabinet structure having a freezing chamber and a food preserving chamber, a refrigerating mechanism associated with said cabinet including a freezing unit in said freezing chamber, an elongated sinuous substantially horizontal conduit forming an air cooling unit-position in the upper part of said food preserving chamber, a generator and an absorber arranged for circulation of absorption solution therebetween, means arranged to receive refrigerant vapor from said generator and to supply refrigerant liquid to said freezing unit, means for conducting an inert pressure equalizing medium from said absorber to said freezing unit, means for conducting cold pressure equalizing medium and refrigerant vapor from said freezing unit to said cooling unit, means for conducting pressure equalizing medium and refrigerant vapor from said cooling unit to said absorber, and means operative to supply refrigerant liquid from said refrigerant liquid supply means to said air cooling unit in response to a predetermined thermal condition in said food preserving chamber.

15. A refrigerating device comprising a cabinet circuit being so arranged that inert gas disconstruction including a storage compartment having high and low temperature chambers, and a mechanism compartment arranged for flow of cooling air therethrough, a cooling unit in each of said chambers, a generator and an air cooled condenser in said mechanism compartment connected to receive refrigerant vapor from said generator, an air cooled absorber in said mechanism compartment connected with said generator to form a solution circuit and also connected with said cooling units to form an inert gas circuit, said inert gas circuit being so arranged that the inert gas flows through the cooling unit in said low temperature chamber, then through the cooling unit in said high temperature chamber and then through said absorber, means for supplying liquid refrigerant from said condenser to the cooling unit in said low temperature chamber, means for diverting the liquid refrigerant produced in said condenser to said high temperature chamber upon the occurrence of a predetermined condition, 'means providing for exchange of heat between inert gas flowing to and from said cooling unit in said low temperature chamber, and means providing for exchange of heat between inert gas flowing to and from said absorber.

16. A refrigerating apparatus including first and second cooling units, means for producing a refrigerating medium and for supplying such medium to said first cooling unit, means responsive to the temperature of said second cooling unit for diverting said refrigerating medium to said second cooling unit, first refrigeration demand -responsive means for governing the production of refrigerating medium in response to the condition of said first cooling unit, and a second refrigeration demand responsive means responsive to the condition of said second cooling unit for taking over control of the refrigerating medium charged from said absorber flows through said first cooling unit and then through said second cooling unit, means forproducing refrigerant vapor, means for converting said vapor to a liquid and for supplying the liquid to said first cooling unit, and means responsive to the thermal condition of the inert gas discharging from said second cooling unit for diverting said liquid to said second cooling unit whenever the temperature of said inert gas exceeds a predetermined value.

18. An absorption refrigerating apparatus comprising a first cooling unit, a second cooling unit, an absorber connected to said first and second cooling units to form an inert gas circuit, said circuit being so arranged that inert gas discharged from said absorber fiows through said first cooling unit and then through said second cooling unit, means for producing refrigerant vapor, means for converting said vapor to a liquid,

a collecting vessel connected to receive said liquid, means connected to said vessel above the bottom thereof for conveying liquid from said vessel to said first cooling unit, means connected to said vessel below said means for conveying liquid to said first cooling unit for conveying liquid to said second cooling unit, a valve controlling said means for conveying liquid to said second cooling unit, and means responsive to a condition of the inert gas flowing through said second cooling unit for controlling the operation of said .valve.

19. Refrigerating apparatus comprising a cabinet structure having a freezing chamber and a cooling chamber; refrigerating apparatus associated with said cabinet structure including a freezing unit in said freezing chamber, a cooling unit in said cooling chamber, and means for supplyfreezing chamber, a second condition responsive means responsive to a condition in said cooling chamber, and means arranged to transmit movement of each of said condition responsive means to said control element in a direction to shift said control element from said first position to a second position in which said refrigerant medium supply means is operative tosupply refrigerant medium against the bias of said means urging said control element to said first position, said last mentioned means being so constructed and arranged that said shift mechanism is actuatable by each of said condition responsive means independently and only in a manner to shift said control element to said second position.

20. Refrigerating apparatus comprising a cabinet structure having a freezing chamber and a cooling chamber; refrigerating apparatus associated with said cabinet structure including a freezing unit in said freezing chamber, a cooling unit in said cooling chamber, and means for supplying refrigerant medium to said freezing unit and said cooling unit; and control mechanism comprising an actuatable control element arranged to govern the operation of said refrigerant medium supply means, means urging said control element to a first position in which said refrigerant supply means is rendered inoperative to supply refrigerant medium, a first condition responsive means responsive to a condition in said freezing chamber, a second condition responsive means responsive to a condition in said cooling chamber, eachof said condition responsive means being arranged for independent actuation of said control element from said first position to a second position in which saidrefrigerant medium supply means is rendered operative against the bias of said urging means and manually operable means arranged to vary the operation of one of said condition responsive means without affecting the other of said condition responsive means.

21. Refrigerating apparatus comprising a cabinet structure having a freezing chamber and a cooling chamber; refrigerating apparatus associatedwith said cabinet structure including a freezing unit in said freezing chamber, a cooling .unit in said cooling chamber, and means for supplying refrigerant medium to said freezing unit and said cooling unit; and control mechanism comprising an actuatable control element arranged to govern the operation of said refrigerant medium supply means, means urging said control element to a first position in which said refrigerant supply means is rendered inoperative to supply refrigerant medium, a first condition responsive means responsive to a condition in said freezing chamber, a second condition responsive means responsive to a condition in said cooling chamber, each of said condition responsive means being arranged for independent actuation of said control element from said first position to a second position in which said refrigerant medium supply means is rendered operative against the bias of saidurging means, a resilient member opposing movement of one of said condition responsive means in a direction to operate said control element, and means for varying the resisting force applied to said one condition responsive means by said resilient means.

ARNOLD D. SIEDLE.

. CERTIFICATE OF comcnon.

Patent No. 2, 1 ,505. 7 March 2 191m.

' ARNOLD D. SIEDLE.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, sec- .ond column, line 1-2, for evaporatar read --evaporator--; page 5, sec- -ond column, line 51;, before "preferably" insert "are"; page l first column, line ll, for "evaporated" read --evaporator--; line 15, for "evapo rator E read --evaporator E--; page 6. first column, line "(14,, claim 10, beginning with the word "when" strike out all to and including water in line 14., second column, same page; and that the saidLetters Patent should be read with this correction therein that the same may conform to the rec- -ord of the case inthe Patent Office.

Signed and sealed this. 50th day of January, A. D. 1915.

Leslie Frazer (Seal) Acting Commissioner of Patents.

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