US2266783A

US2266783A - Refrigeration

Info

Publication number: US2266783A
Application number: US181096A
Authority: US
Inventors: Lynger Erik Sigfrid
Original assignee: Servel Inc
Current assignee: Servel Inc
Priority date: 1936-12-31
Filing date: 1937-12-22
Publication date: 1941-12-23
Anticipated expiration: 1958-12-23

Description

" 2 3, 1941. E. s. LYNGER 2,266,783

REFRIGERATION Filed Dec. 22, 1957 4 Sheets-Sheet l BY W W Q IM TORNEY.

' "Dec. 23, 1941.

E. S. LYNGER REFRIGERATION Filed Dec. 22, 1937 4 Sheets-Sheet 2 ATTORNEY.

Dec. 23; 1941. E; s. LYNGER REFRIGERATION Filed Dec. 22, 1937 4 Sheeis-Sheet 5 Dec. 23, 1941. E. s. LYNGER REFRIGERATION 4 Sheets-Sheet 4 Filed Dec. 22, 1937 INV OR.

WW mm.

Patented Dee. 23, 1941 REFRIGERATION Erik Sigfrid Lynger, Stockholm, Sweden, assignor,

by mesne assignment N. Y., a corporation s, to Servel, Inc., New York, of Delaware Application December 22, 1937, Serial No. 181,096 In Germany December 31, 1936 24 Claims.

My invention relates to refrigeration, and

more particularly to an absorption refrigeration system employing an auxiliary pressure equalizing gas. It is an object of the invention to accumulate liquid refrigerant flowing to a cooling element to improve the operation of refrigeration systems of this type. The improvement broadly includes flowing such accumulated refrigerant to a cooling element to effect a low refrigeration temperature quickly when operation of a refrigeration system is started, as at the termination of a defrosting period, for example, and to effect quick freezing or additional refrigeration during normal operation upon increase in demand for refrigeration.

I accomplish this by storing or accumulating liquid refrigerant during normal operation of a refrigeration system at a place between a place of condensation and a low temperature place of evaporation. In order to effect a low refrigeration temperature quickly during starting, or to effect quick freezing or additional refrigeration during normal operation, a portion of the accumulated refrigerant is evaporated to force the remaining refrigerant to the place of evaporation. Evaporation of a portion of the accumulated refrigerant may be effected either by direct application of heat or by indirect heat transfer through parts of the refrigeration system.

The invention, together with the above and other objects and advantages thereof, will be more fully understood upon reference to the following description and accompanying drawings forming a part of this specification, and of which Fig. 1 illustrates more or less diagrammatically a refrigeration system embodying the invention; Fig. 2 illustrates a modification of the invention; Figs. 3a and 3b are views diagrammatically illustrating a condenser which may be employed in refrigeration systems embodying the invention; Fig. 4 is a fragmentary sectional view of another modification of the invention which may be employed in the refrigeration systems shown in Figs. 1 and 2; Fig. 5 is a sectional view taken at line 5-5 of Fig. 4; Fig. 6 is a fragmentary sectional view of a further modification of the invention similar to that shown in Figs. 4 and 5; and Figs. 7 and 8 illustrate still further modifications of the invention.

Referring to Fig. 1, I have shown the invention embodied in an absorption refrigeration system of a uniform pressure type, generally as described in Patent No. 1,837,767 to Thore M.

Elrving. in which an auxiliary pressure equalizing gas is employed. The system includes a cooling element or evaporator l0 disposed in an enclosed space H which may form part of a food storage compartment of a thermally insulated cabinet l2. Liquid refrigerant, such as ammonia, is introduced through a conduit I 4 into the cooling element 40 and evaporates and diffuses therein into an inert gas, such as hydrogen, to produce a refrigerating effect.

The resulting gas mixture of refrigerant and inert gas flows from cooling element I!) through conduit l5, gas heat exchanger I 6, conduit H and accumulation vessel I8 into an absorber I9. In absorber l9 refrigerant vapor is absorbed by a suitable liquid absorbent, such as Water, which enters through a conduit 20. The inert gas, which is practically insoluble and weak in refrigerant, is returned to cooling element I 0 through a conduit 2|, gas heat exchanger l6, and conduit 22 which is disposed about the conduit l4 within cooling element In; and the absorption liquid flowing downward through absorber I9 in counter-flow to the gas mixture becomes enriched in refrigerant and passes into accumulation vessel l8.

From accumulation vessel l8 enriched absorp tion liquid is conducted through a conduit 23 and liquid heat exchanger 24 to a coil 25 which is disposed about a flue 26 extending vertically upward through a generator 21. By heating generator 21, as by a gas burner 28, for example, refrigerant vapor and absorption liquid are raised by vaporlift action through conduit 29 tothe upper part of generator 21. Liberated refrigerant vapor entering generator 21 through conduit 29, as well as refrigerant vapor expelled from solution in the generator, flows upward in conduit 30 through an air-cooled rectifier 3|. From rectifier 3| refrigerant vapor flows into an air-cooled condenser 32 provided with a plurality of cooling fins 33. Refrigerant vapor is liquefied in condenser 32 and returned to cooling element I 0 through conduit I4 to complete the refrigerating cycle.

A portion of conduit I4 is arranged in thermal exchange relation with the passage. in gas heat exchanger lfi through which enriched gas flows from cooling element l0 toward absorber IS. The absorber I!)v may be air-cooled in any suitable manner or cooled by a cooling medium fiowv ingin thermal exchange relation therewith.

In accordance with my invention I provide a vessel 35 to accumulate liquid refrigerant at a place outside the refrigerator cabinet I2. The vessel 35 is arranged in heat transfer relation with the lower end of conduit 30 by a metal memher 36. Liquid refrigerant is introduced into the upper part of vessel 35 through a 'U-shaped con.-

duit 31 which is connected at its upper end to an upper part of condenser tains refrigerant vapor.

The conduit 31 may be formed into the same shape as condenser 32 and arranged to extend through openings in cooling fins 33. The upper part of conduit 31 serves as an auxiliary condenser in which a portion of the refrigerant vapor is liquefied and conducted into vessel 35.

To the lower part of vessel 35 is connected one end of a second U-shaped conduit 38 which is connected at its other end to the lower part of condenser 32. One end of a third U-shaped conduit 39, which is of less height than U-shapcd conduit 38, is connected to the lower end of condenser 32 at a point above the connection of conduit 39 to the condenser. The opposite end of conduit 39 is connected to an overflow member or funnel 40 which extends through the bottom of vessel 35 and terminates in the upper part thereof.

During normal operation of the refrigeration system the vessel 35 is filled with liquid refrigerant, as will be explained hereinafter. With the vessel 35 filled with liquid refrigerant and assuming that the refrigeration system has been shut down, all of the parts of the system are substantially at the same temperature. When the operation of the system is started by applying heat to generator 21, refrigerant vapor is immediately formed in cell 25 and raised by vaporlift action through conduit 29 into the upper part of generator 21.

Due to the rise in temperature of generator 21, heat is conducted through metal member 36 to the accumulation vessel 35, whereby liquid refrigerant is heated and evaporated in the latter. The vapor produced in this manner is trapped in the upper part of vessel 35 due to the liquid seals provided by the U-shaped

conduits

31 and 39. Due to the vapor pressure in the upper part of vessel 35, a small quantity of liquid refrigerant is forced through U-shaped conduit 38 into the lower end of condenser 32. From condenser 32 such liquid refrigerant flows through conduit ll into cooling element Ill, whereby a refrigerating effect is produced in the cooling element practically immediately when heat is applied to the generator.

when the above occurs the pressure in condenser 32 has not increased to such a value that condensation of refrigerant vapor will take place therein. Upon first starting operation of the refrigeration system, as just described, the condenser temperature is considerably lower than the temperature of vessel 35 due to the transmission of heat through metal member 3t.

After an interval of time, which may be assumed to be an hour, for example, all of the liquid refrigerant is gradually forced out of vessel 35 into cooling element l9. Preferably the amount of refrigerant contained in vessel 35 is such that condenser. 32 will supply the desired quantity of refrigerant to cooling element i3 32 which normally conwhen all of the refrigerant has been forced out of vessel 35.

The vapor pressure increase after all of the' refrigerant has been forced therefrom, and, when this vapor pressure is sufficiently great, liquid is forced out of U- shaped conduit 39 whereby condenser 32 and vessel 35 are in open fluid communication. Under these conditions, the condenser 32 and in vessel 35 continues to Refrigerant vapor vessel 35 are at the same pressure and they automatically assume the same temperature.

With no liquid *in conduit 39 condensate formed in the auxiliary condenser or upper part of conduit 31 flows through the latter into vessel 35, whereby the accumulation vessel is gradually filled with liquid refrigerant. A small quantity of liquid refrigerant may evaporate in the warmer or left-hand end of vessel 35, but the vapor formed in this manner condenses in the colder or right-hand end of the vessel, or in condenser 32 which is at the same temperature as the colder end of vessel 35. When vessel 35 is filled with liquid refrigerant to the same height as the upper end of the member or funnel 30, further liquid entering vessel 35 overflows into-funnel 49 and U-shaped conduit 39, whereby a liquid seal is again produced in this conduit. In this manner vessel 35 is filled with liquid refrigerant during normal operation of the system, and the conditions assumed above are re-established.

By making auxiliary condenser or conduit 31 of suflicient height, refrigerant condensing therein will overflow into funnel. 40 and U- shaped conduit 39, and thence through conduit l4 into cooling element In. After vessel 35 is filled, therefore, the auxiliary condenser formed by the upper part of conduit 31 may be utilized during normal operation of the refrigeration system.

After liquid refrigerant overflows from vessel 35 into funnel 49 and U -shaped conduit 39 to provide a liquid seal, the condenser 32 and vessel 35 are no longer in open fluid communication. Under these conditions the vessel 35 and condenser 32 may be maintained substantially at the same temperature by providing sufiicient heat radiating surface on vessel 35, so that the heat transmitted to the vessel through metal member 39 minus the heat radiated from the vessel is substantially the same as the heating effected in condenser 32 by the refrigerant vapor less the cooling effected by surrounding air.

The rate at which liquid refrigerant flows from vessel 35 into cooling element 19 may be controlled by regulating the transfer of heat to the vessel, as will be described hereinafter. The rate 3 of flow of liquid from vessel 35 is also dependent upon the size thereof. As liquid is gradually forced out of vessel 35 and the liquid level therein drops, the greater will be the column of liquid which must be balanced by vapor pressure to cause flow of liquid. As the liquid level in .vessel 35 falls, therefore, the greater the vapor pressure in the vessel must be for liquid to flow into the lower end of condenser 32 and thence to cooling element Ill. The dimensions of vessel 35, i. e. the depth and width, therefore, also determine the rate at which liquid flows from the vessel into cooling element ii.

In Fig. 2 I have shown the invention embodied in an absorption refrigeration system of the,

above type having two cooling elements Ilia and [0b. The parts of the refrigeration system in Fig. 2 which are similar to parts in Fig. 1 are designated by thesame reference numerals.

from generator 21 flows upward through conduit 33 into the upper section 320 of an air-cooled condenser. The refrigerant liquefied in condenser section 32(1- flows through conduits 4|, Ma and 35 into the upper end of cooling element Ila into which inert gas is introduced from aconduit22a. The resultingrich gas mixture produced in cooling element lll'a flows therefrom through gas heat exchanger l6 and conduit Ila into the lower end of an aircooled absorber l9a. Inert gas, which is weak in refrigerant vapor, passes upwardly from absorber l9a through gas heat exchanger [6 and conduit 22a into the upper end of cooling element Illa.

When all of the refrigerant vapor is not condensed and liquefied in condenser section 32a, refrigerant vapor passes from the lower end of conduit 4| into the lower section 32b of the condenser. The refrigerant vapor liquefied in condenser section 32b flows through conduits 42 and I 4b into cooling element lllb which is connected by

conduits

43 and 44 to the gas heat exchanger l8. Liquid refrigerant evaporates and diffuses into rich gas which circulates through cooling element Hlb with consequent absorption of heat from the liquid refrigerant and the surroundings.

The cooling element ll'lb may be employed for cooling the storage compartment II in which both cooling elements are disposed, a plurality of fins 45 being provided on the cooling element lBb to increase the effective heat transfer surface. The liquid refrigerant cooled in cooling element lob fiows through conduit 46 into the upper end of cooling element Ina which may be employed as a freezing unit.

The lower end of condenser section 32b is connected by conduit 42, vessel 41, and conduit 48 to the gas circuit, as at a gas heat exchanger It, for example, so that any inert gas which may pass through the condenser can flow to the gas circuit and not be trapped in the condenser. Refrigerant vapor not liquefied in the condenser will flow through conduit 42 to displace inert gas in vessel 41 and force such inert gas through conduit 48 into the gas circuit, thereby raising the total pressure in the systemso that an adequate condensing pressure is obtained for the increased temperature of the condenser.

As in the embodiment first described, the vessel .35 is arranged in heat transfer relation with the lower end of conduit 30 by the metal member 36. Due to the withdrawal of heat at the lower end of conduit 30 by metal member 36, this region of conduit 30 serves as a rectifier whereby any water vapor accompanying refrigerant vapor is condensed and drains back to generator 21.

The conduit 31 through which liquid refrigerant is introduced into the upper part of vessel 35 is connected at its upper end to conduit 4|. The upper part of conduit 31 may extend through openings in cooling fins 33a and serve as an auxiliary condenser in which refrigerant vapor is liquefied and conducted into vessel 35. In this modification U-shaped conduit 38 is connected at its upper end to conduit l4a through which liquid refrigerant flows to the upper end of cooling element la. refrigerant overflows through funnel 40 is connected at its upper end to conduit 42.

During normal operation of the refrigeration system shown in Fig. 2, the vessel 35 is filled with liquid refrigerant in a manner similar to that described above in connection with the embodiment of Fig. 1. Assuming that the. refrigeration system has been shut down and that all the parts thereof are substantially at the same temperature, the application of heat to generator 2'! by burner 28 practically immediately causes -evaporation of liquid refrigerant in vessel 35. Due to the vapor pressure in vessel 35, liquid refrigerant U-shaped conduit 39 into which liquid is forced through U-shaped conduit 38 into conduit Na and thence to cooling element Illa. The

vapor pressure in vessel 35 continues to increase after all of the refrigerant has been forced therefrom, and, when this vapor pressure is sufficiently great, liquid is forced out of U-shaped conduit 39 whereby the lower section 32b of the condenser and vessel 35 are in open fluid communication. With no liquid in conduit 39 condensate formed in the auxiliary condenser or upper part of conduit 31 fiows into vessel 35, so that the accumulation vessel is gradually filled with liquid refrigerant.

If desired, the lower end of condenser section 32a may be connected to a liquid cooled rectifier 49 which is located in conduit 30, as shown in Fig. 8. The refrigerant liquefied in condenser 32a flows into rectifier 49 and thence from the latter through conduits I 4a and 46 to cooling element Illa. Water vapor accompanying the refrigerant vapor in conduit 30 is condensed in rectifier 49 and drains back to generator 21. The vapor produced in rectifier 49 due to condensation of water vapor fiows into condenser section 32b, whereby a small quantity of liquid refrigerant is constantly supplied to cooling element lllb. This differs from the modification shown in Fig. 2 in which liquid refrigerant flows into cooling element lob only when all of the refrigerant vapor is not condensed in condenser section 32.

In Fig. 8 a conduit 50 is provided which extends from the lower part of U-shaped conduit 31 and at its upper end is in communication with condenser section 32b. Such a conduit connection may be provided in the modification of Fig. 2, as shown in dotted lines in this figure, but is advantageously employed in the modification of Fig. 8 in which the liquid cooled rectifier 49 is provided and some liquid refrigerant is always flowing from condenser section 32b to cooling element I 0b. By providing the branch conduit 50 liquid refrigerant formed in condenser section 32b is also introduced into vessel 35 to assist in filling the latter. The conduit 50 may be connected to the lower end of condenser section 32b in such a manner that refrigerant liquefying in condenser section 32b first flows into vessel 35 to fill the latter before liquid refrigerant fiows through conduit |4b into the space cooling element I 0b.

In Figs. 3a and 3b are shown a condenser 320 which may be advantageously employed in refrigeration systems of the type shown in Figs. 1 and 2 and embodying the invention. The condenser 32'cis formed of tubing having straight portions and bends. The condenser comprises several sections similar to that shown in Fig. 3b which are connected in series and arranged in a number of different branches, as shown in Fig. 3a. The sections of the condenser are preferably formed so that all of the straight portions are exposed to the upwardly flowing cooling air with none of the straight portions screening off other straight portions of the condenser. A reduction in the amount of space occupied by a condenser is effected in the particular structure of Figs. 3a and 3b, and the condenser may be arranged to effect condensation of the refrigerant vapor without the necessity of providing cooling fins.

In Figs. 1 and 2 the invention has been embodied in refrigeration systems to effect a low refrigeration temperature quickly when operation of a system is started. This is particularly advantageous when operation of a system is started after being shut down for sometime to effect defrosting of a cooling element. By employing the present invention, the length of time required to effect a low refrigeration temperature at the termination of a defrosting period is shortened considerably.

In addition to shortening the time required during starting of a system to effect alow refrigeration temperature, the invention may be also employed to take care of a temporary increase in load on the evaporator or cooling elel ment upon increase in demand for refrigeration. Such a modification is shown in Figs. 4 and in which transfer of heat from conduit to vessel may be controlled or regulated. The conduit 3|! through which refrigerant vapor flows from generator 21 to condenser 32, as in the embodiment of Fig. l, for example, is provided with a l c et The Jacket 5| includes a sleeve portion 52 which is disposed abouta greater part of vessel 35. About the sleeve portion 52 is arranged a rotatable 2o collar 53. The sleeve portion 52 and collar 53 are provided with a plurality of elongated slots 54' and 55, respectively.

When the

slots

54 and 55 coincide and are in alignment, air is permitted to circulate about 2.5

vessel 35 whereby the latter is effectively cooled and no evaporation of liquid refrigerant in vessel 35 takes place. When collar 53 is rotated so thatthe

slots

54 and 55. are out of alignment and collar 53 covers the slots 54, air within jacket 5| 30 is heated by conduit 3|l. Due to heating of air surrounding vessel 35, liquid refrigerant in the latter is heated and evaporated to cause flow of liquid refrigerant into the cooling element.

When trays containing water to be frozen are 35 placed in a freezing unit, the load on the cooling element is temporarily increased and more liquid refrigerant can evaporate and diffuse into inert gas. By providing the modification of Fig. 4 the collar 53 may be turned to cover the openings 54 and substantially immediately cause flow of liquid, refrigerant into the cooling element to take care of the temporary increase in load. IThus, the modification of Fig. 4 permits quick freezing in the portion of a cooling element which is utilized as the freezing unit.

In Fig. 6 is illustrated another modification similar to that shown in Figs. 4 and 5 in which a jacket 55 is disposed about conduit 30 and a greater portion of vessel 35. The jacket 55 is provided with flaps 51 at the top and bottom thereof which permits circulationof air about vessel 35 when in an open position.; When itrisi ,7

desired-to effect flow of liquid refrigerant from vessel 35 tothe cooling element, the flaps 51 are moved to their closed positions, whereby heating of air within jacket is effected tocauseheai'e ing and evaporation of liquid refrigerant within vessel 35. I.

In both the modifications of Figs. 4 and 6 suitable control mechanism may be provided which is operable either at the front of a refrigerator cabinet or in the food storage com rtment, as at the location of the cold and defr sting control, whereby flow of additional liquid refrigerant into a cooling element is readily effected. In ad:- dition to controlling the heating of vessel 35 in the manner just described the heat conducting member 36 of Figs. land 2 may be provided with a relatively large opening adapted toreceive a metal plug. When the metal plug is positioned in the opening, heating of vessel 35 is readily effected to cause fiow of additional refrigerant into a cooling element. When the metal plug is renovedfrom the opening, the heat conductive In Fig. 'l I have shown a still further modifica tion in which parts similar to those shown in Fig. 1 are designated by the same reference numerals. In this modification a single path of flow is provided for refrigerant fluid from generator 21 to cooling element |5 and thus differs in'this respect from the arrangements of Figs. 1 and 2 which provide parallel paths of flow of refrigerant fluid from the generator to the cooling element. Condenser 32 is connected by conduit 34 to the gas circuit, as, for example, to gas heat exchanger l5.

In Fig. 7 all of the refrigerant vapor condensed in condenser 32 flows through U-shaped conduit 31 into accumulation vessel 35. From vessel 35 liquid refrigerant flows through U-shaped con- ,duit 39 into the upper part of cooling element l5 and replaces the conduit ll of Fig. 1. The overflow funnel 49 is connected to one end of vessel 35 and is connected to U-shaped conduit 39 which is connected to a point higher than the connection of conduit 31 to the condenser.

To the lower end of vessel I3 is connected a conduit 59 which is connected at its other end to a coil 59. The upper end of coil 59 is connected by a conduit 55 to the upperpart of generator 21, a portion of conduit 59 being arranged 'in thermal exchange relation with vessel 35. Coil it is desired 'to effect a low refrigeration temperature quickly upon startinggelectrical heating element 5| may be connected to a source of electrical supplyto cause flow of absorption liquid in coil 59 and conduit 55. With this arrangement heating'of vessel 35 may be effected without applying heat to generator 21. By providing a branch circuit for absorption liquid-and heating and causing flow of this liquid by heating element 5|, liquid refrigerant in vessel 35 is quickly heated and evaporated to cause flow of liquid refrigerant from the vessel into cooling element It.

5 During normal operation of the refrigeration system, the heating element 5| may be energized at any time to cause flow of liquid refrigerant from vessel 35 to effect quick freezing upon increase in demand for refrigeration. If desired, the heating of coil 59 and generator 21 may be regulated by a single control. When generator 21 and coil 59 are each provided with an electricalheating element, for example, the control mechanism may be so arranged that when increased refrigeration is desired, a common con- .trol member may be moved to a maximum cold position whereby only the heating element for coil 59 is energized. When the control member is moved from its "maximum cold position to another operating position, the heating element for coil 59 may be deenergized'and the electrical heating element for generator 21 may be energized to effect normal operation of the refrigeration system.

If desired, a conduit 52 (which is indicated in dotted lines in Fig. 7) may be provided which is connected to the lower end or inlet of coil 59 and also to the lower end of coil 25, so that a portion of the enriched absorption liquid flows upward through coil 59 and another portion thereof flows to the coil 25.

When vessel 35 is heated to cause flow of refrigerant therefrom to the cooling element [0, it is preferable to effect the heating in such a manner that a gradual flow of refrigerant is effectedwhereby substantially all of the refrigerant evaporates and diffuses into inert gas in the cooling element. When the flow of refrigerant into the cooling element is too rapid and all of the refrigerant does not evaporate in the cooling element, such unevaporated refrigerant passes out of the cooling element without producing useful refrigeration. In order to' avoid unevaporate'd refrigerant passing out of the cooling element, members in the lower part of the cooling element may be provided to retain such unevaporated refrigerant in the cooling element.

While I have shown and described particular embodiments of the invention, I do not wish to be limited to the particular arrangements set forth, and I therefore aim in the following claims to cover all modifications and changes that fall within the true spirit and scope of the invention.

What is claimed is:

1. In the art of refrigeration employing a system using inert gas into which refrigerant evaporates at a place of evaporation, the improvement which consists in accumulating liquid refrigerant during normal operation of the system, and evaporating a portion of such accumulated refrigerant to create pressure to force such refrlgerant to the place of evaporation to produce useful refrigeration when the, quantity of liquid refrigerant being produced is insumcient to supply the demand for refrigeration.

2. In the art of refrigeration employing a system using inert gas into which refrigerant evaporates at a place of evaporation, the improvement which consists in accumulating liquid refrigerant during normal operation of the system, flowing the accumulated liquid refrigerant to the place of evaporation by evaporating a portion thereof when the quantity of liquid refrigerant being produced is insufficient to supply the demand for refrigeration, and again accumulating liquid refrigerant during normal operation of the system when the quantity of accumulated liquid refrigerant is reduced.

3. In the art of refrigeration employing a system using inert gas into which refrigerant evaporates at a place of evaporation, the improvement which consists in accumulating liquid refrigerant during normal operation of the system, and utilizing heat derived from a part of the system to evaporate a portion of the accumulated refrigerant to cause flow thereof to the place of evaporation to produce useful refrigeration when the quantity of liquid refrigerant being produced is insufficient to supply the demand for refrigeration.

4. In a refrigerating system, means to produce liquid, an evaporator, conduit means to flow liquid from said liquid producing means to said evaporator, means to flow inert gas to said evaporator, a trap in said liquid conduit, means to accumulate liquid, and means to evaporate a portion of said accumulated liquid by heat derived from said system to force such liquid to said evaporator to produce useful refrigeration when the quantity of liquid being produced is insuflicient to supply the demand for refrigeration.

5. In the art of refrigeration employing a system using inert gas into which liquid refrigerant evaporates at a place of evaporation, the liquid refrigerant being produced at a place of condensation, the improvement which consists in accumulating refrigerant during normal operation of the system, and flowing such accumulated refrigerant to the place of evaporation when operation of the system is started after a shut down period of the system and the quantity of liquid refrigerant being produced is insuflicient to supply the demand for refrigeration..

6. In the art of refrigeration employing a system using inert gas into which refrigerant evaporates at a place of evaporation, the improvement which consists in dividing refrigerant fluid into a plurality of paths of flow, producing liquid refrigerant in one of said paths of flow, flowing refrigerant in said one path of flow to the place of evaporation, accumulating refrigerant fluid in liquid phase in another of the paths of flow, and flowing such accumulated refrigerant to the place of evaporation to produce useful refrigeration when the quantity of liquid refrigerant being produced in said one path of flow is insuflicient to supply the demand for refrigeration.

7. In the art of refrigeration employing a system using inert gas into which refrigerant evaporates at a place of evaporation, the improvement which consists in dividing refrigerant fluid flowing toward said place of evaporation into two parallel paths of flow, accumulating refrigerant fluid in liquid phase in one of the paths of flow, and heating such accumulated refrigerant to cause flow thereof to the place of evaporation to produce useful refrigeration when the rate of flow of refrigerant to the place of evaporation through said other path of flow is insuiflcient to supply the demand for refrigeration.

8. In the art of refrigeration in which evaporation of liquid refrigerant takes place in the presence of an inert gas at a place of evaporation, the improvement which consists in flowing liquid refrigerant from a place of condensation to the place of evaporation in a single path of flow, accumulating an appreciable quantity of liquid refrigerant at a place between said places of evaporation and condensation, and flowing such accumulated refrigerant to the place of evaporation when the quantity of liquid refrigerant being produced is insufiicient to supply the i being expelled from said absorption solution, and,

after a shut down period during which the expulsion of fluid out of absorption solution is reduced, flowing the accumulated liquid to said place of evaporation substantially immediately when expulsion of said fluid from absorption solution is again instigated and the quantity of liquid being produced is insufficient to supply the demand for refrigeration.

1 10. A method of refrigeration which consists in expelling a cooling agent from solution from an absorption liquid, converting said cooling agent to liquid phase, evaporating said cooling agent in the presence of an auxiliary agent, absorbing said cooling agent in said absorption liquid, circulating said auxiliary agent between the place of evaporation and the place of absorption, circulating said absorption liquid between the place of absorption and the place of expelling, accumulating cooling agent after being converted into liquid phase, and flowing said accumulated. cooling agent into the presence of said auxiliary agent to produce useful refrigeration when the quantity of liquid being produced is insufficient to supply the demand for refrigeration.

11. In a refrigerating system, a generator, a condenser, and an evaporator, conduit means connecting said aforementioned parts whereby refrigerant expelled out of solution in said generator is condensed in said condenser andflows to said evaporator, means, to flow inert gas to said evaporator, a trap in said conduit means to accumulate liquid refrigerant, and means to effect heating of said accumulated liquid substantially immediately when the supply of heat to said generator is increased after a shut down period of said system, such as defrosting, for example, whereby a portion of such accumulated liquid is evaporated to force such liquid to said evaporator to produce useful refrigeration when the quantity of liquid being produced is insuflicient to supply the demand for refrigeration.

12. Absorption refrigeration apparatus comprising a generator, a condenser, an absorber, an evaporator, and conduits connecting said aforementioned parts to provide a circuit for circulation of absorption liquid between said generator and said absorber, a circuit for circulation of cooling agent through said generator, condenser, evaporator and absorber, and a circuit for circulation of an auxiliary agent between said absorber and evaporator, means in said circuit for cooling agent for accumulating liquid cooling agent, means to cause flow of such accumulated cooling agent to said evaporator to produce useful refrigeration when the quantity of liquid cooling agent being produced is insufficient to supply the demand for refrigeration, and means for controlling said last mentioned means.

V 13. Absorption refrigeration apparatus including an evaporator constructed and arranged for flow of gas therethrough and downward flow of liquid in the presence of gas, members for conducting gas and liquid to and from said evaporator, means for accumulating an appreciable quantity of liquid, and means for flowing such accumulated liquid to said evaporator into the presence of the gas to produce useful refrigeration when the quantity of liquid being produced insufficient to supply the demand for refrigera- 14. In a method of refrigeration which consists in circulating a fluid and evaporating such fluid into an auxiliary agent, absorbing said fluid in an absorption solution, expelling said fluid from said solution, and condensing said fluid to liquid, that improvement which consists in accumulating an appreciable quantity of said fluid at a place between the places of condensation and evaporation, and flowing such accumulated fluid to the place of evaporation and evaporating said fluid in the presence of an auxiliary agent when the quantity of said fluid expelled from said solution and condensed to liquid is insufficient to supply the demand for refrigeration.

15. In the art of refrigeration employing a system using inert gas into which refrigerant evaporates at a place of evaporation, the improvement which consists in accumulating liquid refrigerant during-normal operation of the system, and evaporating such accumulated refrigerant to trap vapor above the liquid surface level thereof to force such accumulated refrigerant in a path of flow extending from the body of accumulated liquid below the liquid surface level to the place of evaporation.

16. In the art of refrigeration employing a system using an inert gas into which refrigerant evaporates at a place of evaporation, the improvement which consists in accumulating liquid refrigerant during normal operation of the system, evaporating such accumulated refrigerant to trap vapor above the liquid surface level thereof to force such accumulated refrigerant from a region below the liquid surface level to the place of evaporation, and again accumulating liquid refrigerant after releasing the trapped vapor.

17. The improvementas set forth in claim 16 in which released vapor is conducted to a place of condensation.

18. In absorption refrigeration apparatus having a generator, a condenser, an absorber, an evaporator, and conduits connecting the aforementioned parts to provide a circuit foicirculation of absorption liquid between the generator and the absorber, a circuit for circulation of cooling agent through the generator, condenser, evaporator and absorber, and a circuit for circulation of an auxiliary agent between the absorber and the evaporator, means for accumulating liquid cooling agent flowing from the condenser, and means to utilize the absorption liquid circuit to heat accumulated cooling agent and cause flow thereof to the evaporator to produce useful refrigeration when the quantity of liquid cooling agent being produced is insufficient to supply the demand for refrigeration.

19. In an absorption refrigeration system having a generator, a condenser, and an evaporator, means to accumulate liquid flowing from the condenser, means to utilize heat from vapors produced in the generator for forcing accumulated liquid to the evaporator to produce useful refrigeration, and means to control heating of accumulated liquid by said last-mentioned means.

20. In an absorption refrigeration system having a condenser and an evaporator, a receiver, means including a flrst liquid trap to'conduct liquid to an upper part of said receiver during operation of the system, means including a second liquid trap to provide communication between an upper part of said receiver and said condenser, means including a third liquid trap for conducting liquid from a lower part of said receiver to said evaporator, and means to heat liquid in said receiver to form and trap vapor above the liquid surface level when said second liquid trap is filled with overflow liquid from said receiver and said first liquid trap is fllled with liquid flowing to said receiver, whereby liquid is caused to flow through said third liquid trap from said receiver to said evaporator. n

21. In an absorption refrigeration system having a generator, a condenser, and an evaporator, conduit means to conduct refrigerant vapor from the generator to the condenser and liquid condensate from the condenser to the evaporator, a trap connected to receive and accumulate liquid during operation of the system, and means to transfer heat from vapors produced in the generator to liquid in the trap to vaporize such form vapor to force liquid from the produced is insuflicie'nt to supply the demand for refrigeration.

22. In the art of refrigeration employing a heat operated absorption system using inert gas, the improvement which consists in accumulating liquid refrigerant at a first place in the system during heat input'to the system, and vaporizing liquid refrigerant and trapping such vapor above the liquid surface level of the accumulated refrigerant to force such liquid in a path of flow extending from the body of accumulatedliquid below the liquid surface level to another place in the system.

23. A method of refrigeration which includes the steps of expelling refrigerant fluid from an absorbent at a place of expulsion, liquefying the expelled refrigerant fluid at a place of condensation, and flowing the liquid refrigerant into the presence of an inert gas at a place of evaporation. accumulating liquid refrigerant at a place of acplace'of evaporation in order to supply liquid refrigerant to the place of evaporation at a rate greater than the rate aflwhichrefrigerantfluid is liquefied at the place of condensation. 1

24. An absorption refrigeration system containing an auxiliary agent and includinga generator, a condenser and an evaporator, conduit means connecting said aforementioned parts whereby refrigerant fluid expelled from an absorbent in said generator is liquefied in said condenser and such liquid is conducted to 'said evaporator for evaporation in the latter in the presence of the auxiliary agent, and structure 'for supplying liquid to'said evaporator at'a rate greater than the rate at which liquid refrigerant is formed in ERIK SIGFRID LYNGER.