US2317283A - Refrigeration - Google Patents

Description

A ril 20, 1943. E. s. LYNGER 2,317,233

' REFRIGERATION Filed June 22, 1938 5 Sheets-Sheet l' 2a F? ,OR

QQH W ATTORNEY.

April 20, 1943.

E. s. LYNGER 2,317,283

REFRIGERATION Filed June 22, 1938 5 Sheets-Sheet 2 IN VENTOR.

p 1943- E. s. LYNGER 2,317,283

REFRIGERATION Filed Juhe 22, 1938 5 Sheets-Sheet 3 E. s. LYNGER 2,317,283

REFRIGERATION April 20, 1943.

Filed June 22, 1938 5 Sheets-Sheet 5 W INVENIT R. BY w L4 ATTORNEY.

Patented Apr. 20,

w I SigfridLY I a by memo asslgnm f: York, N. Y.,

Stockholm, Swedem'assignor, cuts, to Serve], Inc., Now a corporation of Delaware rmany July 6, .1937

. 'nppllcationlune 22,-1938, Serial No. 215411 p mac 7 I Claims.

This invention relates to refrigeration, and it is an object ofthe invention to provide an improvement for transferring heat whereby cooling may be effected at one or a plurality of places at a higher level than a .source ofrefrigeration.

The above and other objects and advantages of the invention will'become ap arent from the following description taken in conjunction with the accompanying drawings forming a part of this specification, and of which: I

Fig. 1is a view more or less diagrammatically illustrating a refrigeration system together with a heat transfer system embodying the invention;

Fig. 2 is an enlarged view, partly in section, illustrating more clearly the heat transfer system shown in Fig. 1;

Fig. 3 is a fragmentary view diagrammatically illustrating a modification of the invention shown in Figs. 1 and 2 y Fig. 4 is a view more or less diagrammatically illustrating another modification of the invention.

,Fig. 5 is a view diagrammatically illustrating a. further modification of the invention and in which a plurality of places of cooling are provided from the surroundings,

- through a conduit 20, thereby producing a refrigerating effect with consequent absorption of heat The rich gas mixture of refrigerant vapor and inert gas formed in at a higher level than a source of refrigeration;

and

Fig. 6 is a fragmentary view illustrating a still further modification of the invention having a plurality of places of cooling at a higher level than a source of refrigeration.

In Fig.1 the invention is shown in connection with a. refrigeration system of a uniform pressure absorption type. Such a system includes a generator l0, condenser H, evaporator or-cooling element 12, and an absorber l3 which are interconnected in a manner well-known in the art, and which will briefly be described hereinafter. The system contains a solution of refrigerant in absorption liquid, such as ammonia in water, for example, and also an inert gas or auxiliary agent, such as hydrogen.

The generator I9 is heated in any suitable manner, as by a gas. burner H, for example, which projects its flame into lower end of a flue l5. Due to heating by burner 14 refrigerant vapor is expelled from solution in generator Ill. The refrigerant vapor flows upwardly through a conduit l6 into the air-cooled condenser H where the vapor is condensed and flows through conduit l1 into evaporator l2. 7, I

The evaporator I2 is located fife. space or compartment l8 formed by thermally insulated walls evaporator I2 flows therefrom through a conduit 2t, one passage of a gas heatexchanger 22, and conduit 23 into the lower part of absorber 13..

The absorber I3 is diagrammatically shown in the form of a looped coil having a plurality of cooling fins 24 secured thereto forfair cooling. In absorber l3 the rich gas mixture flows counter-current to downwardly flowing weak absorption liquid which enters through a conduit 25. The absorption liquid absorbs refrigerantvapor from the inert gas, and inert gas weak in refrigerant vapor flows from absorber l3 through a conduit 26, a second passage of gas heat exchanger 22, and conduit 20 into the upper part of evaporator l2.

Absorption liquid enriched in refrigerant flows from the lower part of absorber I3 into an accumulation vessel 21. From vessel 21 enriched liquid flows through an inner conduit 28 of a liquid heat exchanger 29 to a coil 30 which is disposed about the lower end of flue l5. Due to heating by burner ll, liquid is raised by vaporlift action from coil 30 through conduit 3| into the upper-part of generator Ill. The refrigerant vapor expelled out of. solution in generator ID, together with refrigerant'vapor entering through conduit 3|, flows upwardly through conduit into condenser I I, 'as explained above.

The absorption liquid from which refrigerant has been expelled flows from generator l0 through conduit 32, outer conduit 33 of liquid v heat exchanger 29, and conduit 25 into the upper part of absorber l3.

The lower end oi condenser H is connected by a conduit 3| to the gas circuit, as at gas heat exchanger 22, for example. By providing conduit 34 anynon-condensible gas which passes through the condenser will flow to the gas circuit and not be trapped in the condenser.

The refrigerating effect produced by evaporator or cooling element l2 of the refrigeration system is utilized to cool and liquify a volatile fluid flowing through a coil 35 which extends longitudinally within the cooling element, as shown in Fig. 2. The coil 35 constitutes the condenser of a heat transfer system embodying the invention whereby cooling may be effected at a place above the cooling element I2.

The heat transfer system includes an evaporator 36 which is of the flooded type and located at a higher level than condenser 35. The evaporator 36 is disposed in a thermally insulated space 31 and includes a receiver 33 having a looped coil 33 connected thereto.

The condenser 35 and evaporator 36 form part of a closed fluid circuit which is partly filled with a suitable volatile liquid. The volatile liquid evaporates in evaporator 36 and takes up heat thereby producing cold. The vapor flows from evaporator 36 through a conduit 43 into condenser 35 in which the vapor is cooled and condensed by cooling element l2.

In accordance with the invention, structure including an accumulation vessel 4| is provided for raising liquid from condenser 35 to evaporator 36 so that cooling may be effected in space 31. To the lower end of condenser 35 is connected a U-shaped conduit 42 which extends below vessel 4| and is connected to the-bottom thereof.

To vessel 4| is connected an overflow conduit 43 having an inverted U-shaped bend 44. In Fig. 2 the upper closed end of bend 44 is at substantially the same level as the upper part of vessel 4|. From bend 44 conduit 43 extends downwardly and is connected to an intermediate part of a vaporizer 45. The vaporizer 45 constitutes a heat receiving part and is shown in heat exchange relation with the upper part of generator l3. Above the connection of conduit 43 the vaporizer 45 is connected by another conduit 46 to the upper part of vessel 4|.

' The operation of the heat transfer system just described is substantially as follows: Assuming that evaporator 36 is filled with liquid, vapor is formed therein and flows through conduit 43 into condenser 35 in which the vapor is cooled and condensed, as explained above. The con densed fluid flows through U-shaped conduit 42 into accumulation vessel 4|. With continued evaporation of liquid in evaporator 36 and condensation of vapor in condenser 35, the liquid level will rise in vessel 4|.

When the liquid level in vessel 4| rises sulficlently, liquid is siphoned by inverted U-shaped bend 44 in conduit 43 and the siphoned liquid flows into vaporizer 45. This may occur when a definite quantity of liquid has evaporated in evaporator 36, such as, for example, half of the liquid in the evaporator.

The liquid overflowing into vaporizer 45 is vaporized and the vapor formed therein flows through conduit 46 into the upper part of vessel 4|. The vapor pressure continues to increase in vaporizer 45, conduit 46, and in the space above the liquid surface in vessel 4| This vapor pressure increases to a value higher than the vapor pressure above liquid in evaporator 36. When the vapor pressure above the liquid surface in vessel 4| builds up sufliciently, liquid is forced upward through conduit 42, condenser 35, and conduit 43 into receiver 33.

The heat transfer system is so constructed and arranged that sufficient liquid is siphoned from vessel 4| into vaporizer 45 before the liquid level is depressed in vessel 4| below the connection of conduit 43 thereto. The quantity of liquid siphoned into vaporizer 45 is suiflcient when the vapor pressure can build up to a value to produce the necessary force to lift liquid from vessel 4| into receiver 38.

When the vapor in vessel 4| reaches the lower end of the right-hand leg of U-shaped conduit of conduit 42, condenser 35. and conduit 43 will flow back into vessel 4| The trapped vapor released into the left-hand leg of U-shaped conduit 42 is condensed in condenser 35 while the remaining vapor in vessel 4| is condensed therein. It will be apparent that vapor is formed in v porizer 45 when the liquid rises suiflciently in vessel 4|, and that this rise of liquid is recurring and constitutes a recurring condition taking place within the heat transfer system to cause intermittent flow of liquid from vessel 4| to condenser 35. Further, the heat transfer system is self-- actuating and operates in accordance with a condition taking place solely within the systemand independently of changes in an operating condition of the refrigerating apparatus or changes in temperature or pressure occurring outside of or external to the heat transfer system.

The periods during which liquid is raised in the system alternate with periods during which vapor is formed in evaporator 36 and condenses in condenser 35. The periods of liquid raising are relatively short compared with the periods of liquid evaporation, whereby space 31 is kept a a low temperature practically all of the time By locating accumulation vessel in space II which is at a low temperature, vaporization of liquid in this vessel is prevented.

At the termination of the periods when liquid is raised to a higher level into receiver 33, the

pressure in the heat transfer system becomes equalized. Since the length of time of the liquid lifting periods is relatively short, very little heat of condensation is transferred to liquid in vessel 4| by the small amount of vapor condensing therein.

In Fig. 3 is diagrammatically shown a modification of the lower part of the heat transfer system of Figs. 1 and 2. As in Fig. 2, the modification of Fig. 3 shows vessel 4| connected to a U-shaped conduit 42 which is connected at its upper end to condenser 35. The upper part of vessel 4| is connected by conduit 46 to the upper part of vaporizer 45 which is in thermal contact with the upper part of generator l3.

In-place of the overflow conduit 43 having an inverted U-shaped bend 44, liquid overflows from vessel 4| in Fig. 3 over the upper peripheral edge 41 of a shallow funnel 43 which is located in any 42 during a liquid lifting period, trapped vapor suitable manner within the upper part of the vessel. The bottom of funnel 48 is connected by a conduit 43 to an intermediate part of vaporizer 45 below the connection of conduit 46.

The operation of the heat transfer system including the modification of Fig. 3 is substantially the sameas that of Fig. 2 and described above. As the liquid level rises in vessel 4| in Fig.- 3, liquid overflows over the upper edge 41 of funnel 43 and flows through conduit 43 into vaporizer 45. The vapor formed in vaporizer 45 flows through conduit 46 into the upper part of vessel 4 I. When the vapor pressure in the upper part of vessel 4| builds up sufficiently, liquid is forced downwardly therein and through conduit 42 into evaporator 36 at the upper level.

The funnel 43 is so dimensioned that when the liquid level in vessel 4| rises to cause overflow of liquid, the overflow is relatively large whereby sufllcient liquid flows into vaporizer 45 before the liquid level in vessel 4| falls below the upper edge 41 of funnel 43. The amount of liquid flowing into vaporizer 45 is sufllcient, as pointed out above in connection with Fig. 2, so that the vapor pressure will build up to a value suflicient to force liquid from vessel 4| into receiver 33.

and 3. The

amazes In Fig. 4 is more or less diagrammatically lllustrated another modification of the heat transfer. systems described above and shown in Figs. 2 parts of the primary refrigeration system similar to those shown in Figs. 1 and 2 are designated by the same reference numerals. The evaporator 36a including receiver 38a and looped coil 39a is at a higher level than condenser 35a which is in thermal exchange relation with cooling element l2. As in the other embodiments previously described, the volatile liquid evaporates in evaporator 36a. and takes up heat thereby producing cold. The vapor flows from evaporator 36a through conduit 40a. into condenser 35a in which the vapor is cooled and condensed by cooling element l2.

Inaccordance with this modification, liquid is raised into receiver 38a bystructure including an accumulation vessel Ma which is more or less in the shape of a vertical cylinder. The lower end of condenser 35a is connected bya U-shaped conduit 42a to the lower part of vessel 4|a. Within vessel 4|a. is disposed a vertical conduit 50 having a coil 5 at the lower end thereof. The lower end of coil 5| is connected by a liquid trap 53 and conduit-52 to anintermediate part of vaporizer 45a. The vaporizer 450, at a point above the connection of conduit 52 is connected by a conduit 54 to the upper end of vertical coriduit 5o.

From the upper part of vessel Ila a'conduit 55 extends downward and is connected at its lower end to the left-hand leg of liquid trap 53. The lower end of conduit 55 is in communication with the lower end of a conduit 56 which is also connected to the left-hand leg of trap 53 below the connection of conduit 55. The upper end of conduit 56 is connectedat 51 to the lower end of conduit 40a and above condenser 35a. The conduits 42a and.56 are connected by a short oblique conduit 58 I The operation of the modificationof Fig. 4 generally is the same as described above in connection with the other embodiments and differs in the'manner in which liquid israised into receiver 38a. -With evaporation of liquid in evaporator 36a and condensation of the vapors in condenser 35a, the liquid level rises in accumulation vessel Ma. .When the liquid level rises sufiiciently in vessel 4|a, liquid overflows from the left-hand leg of U-shaped conduit 42a through oblique conduit 56 and into conduit 56. The liquid overflowing into conduit 56 is conducted through liquid trap vaporizer 45a.

The liquid entering vaporizer 45a is vaporized therein and the vapor flows through conduit 54 into vertical conduit 50 and coil 5|. Since duit 50 and coil are surrounded by liquid which is. at a considerably lower temperature than vaporizer 45a, condensation of vapor takes place in these parts. The condensate flows from coil 5| through liquid trap 53 and conduit 52 back to vaporizer 45a where The vaporizer 45a, conduits 54 and 50, coil 5|, liquid trap Bland conduit 52 constitute a local vaporizationecondensation circuitin which liquid is vaporized in vaporizer 45a and the vapors are condensed in conduit 50 and coil 5|. Liquid vaporizing in vaporizer 45a takes up heat from generator l0, and 50 and coil 5| gives up heat to liquid in vessel Ma.

Whena liquid lifting period is started with overflow of liquid through oblique conduit 58, the vaporization-condensation circuit -just described 53 and conduit 52 into it is again vaporlzed.

the vapors condensing in conduit I of coil 5| is immersed in upwardly through the assures suflicient liquid flowing into vaporizer a to effect heating of liquid in vessel Ma. With heating of liquid in vessel a, evaporation of liquid takes place in this vessel whereby the vapor pressure above the liquid surface builds up, thereby forcing liquid downwardly in vessel Haand left-hand leg of U -shaped conduit 42a.

With liquidrising in the left-hand leg of U- shaped conduit 42a, some liquid overflows through oblique conduit 58 into conduit 56, thereby further assuring sufilcient liquid being introduced into vaporizer 45a so that the'vapor pressure will build up sufficiently to lift liquid into receiver 38a.

As the vapor pressure increases above the liquid surface in vessel Ma, the liquid is depressed in this vessel and also in conduit 55. 'At the same time the columns of liquid rise in the left-hand leg of U-shap'ed conduit 42a and conduit 56 until the condenser 35a and conduit 40a are filled with liquid, and liquid then flows into receiver 38aof evaporator 36a.

As the liquid level in vessel Ma falls due to raising of liquid into receiver' 38a, less and less liquid. With coil 5| no longer immersed in liquid or only partly immersed in liquid, the coil is no longer effectively cooled by the liquid and less and less condensation of vapors takes place therein. When condensation of vapors no longer occurs in coll 5l the generation of vapors stops in vessel a. due

'to evaporation of liquid therein.

The pressure in the vaporization-condensation circuit is determined by the temperature of coil 5|. When condensation of vapors does not take place in coil 5| due to the rise in temperature of in the'vaporization-condensation circuit increases sufflciently so that the liquid trap formed by thelower end .of coil 5| and conduit is forced open. When this occurs vapor formed in vaporizer 450. can enter the upper part of vessel Mo and further lower the liquid level in this vessel until it is completely "empty. 6

When the liquid level 'falls in the right-hand leg of U-shaped conduit 420. so that it is below the iorizontal part of conduit 56, the liquid level will also fall in the left-hand leg of trap 53 to the same extent and vapors can enter the lower end of conduit 56. With suflicient lowering of the liquid level in the right-hand leg of conduit 42a, therefore, the liquid seal at the lower end of conduit 56 is forced open. At this time liquid is forced from trap 53 through conduit 52 into '56 will cause lifting .of liquid therein so that liquid is raised in conduit 56 as well as the lefthand leg of U-shaped conduit 42a. Whenthe lifting vapor in conduit 56 enters the lower end of conduit 40a at 51, the pressure. is equalized at the upper and lower ends of the liquid column in condenser 35a and U-shaped conduit 42a. With such pressure equalization the. liquid .column in condenser 35a and conduit 42a falls.

- and the liquid returns into accumulation vessel The vapor entering the lower end of conduit 400. through conduit 56 condenses in condenser 35a, and flow of such vapor continues until vaporizer 45a no longer contains liquid. 'Since conduit 56 is filled with vapor no liquid enters vaporizer 45a and the liquidlifting period terminates when vaporizer 45a is exhausted of liquid.

a second accumulation vessel 63.

With liquid now raised into evaporator 36a and the pressure equalized in the heat transfer system, evaporation of liquid in evaporator 36a is resumed and condensation of this vapor is efi'ected in condenser 35a. The condensed vapor again accumulates in vessel 4 la and a liquid lifting period is again instigated when liquid-overflows through oblique conduit 58 from conduit 42a into conduit 56.

Fig. 5 diagrammatically illustrates a further modification of the invention which differs from the preceding embodiments in that vapor in the heat transfer system is intermittently returned to the higher level, and, after being condensed at such higher level, may flow to one or a plurality of evaporators.

In the modification of Fig. 5 a plurality of evaporators 36b are provided at a higher level than condenser 35b of the heat transfer system. Each evaporator 36b is disposed in a separate thermally insulated space 31b and includes a receiver 38b and a looped coil 39b. An air-cooled condenser 59 is located above each space 31b and connected at its lower end by a liquid trap 60 to an upper part of a receiver 38b.

Two of the evaporators 36b are disposed one above the other with their associated air-cooled condensers 59 being connected to vertical conduit 40b. The other two evaporators 36b are also disposed one above the other with their associated condensers 59 being connected to vertical conduit 460 which branches off from the lower end of conduit 40b.

As in the previous embodiment, volatile liquid evaporates in evaporators 36b and takes up heat thereby producing cold.' The vapors flow from evaporators 36b through conduits 40b and 400 into condenser 35b in which the vapors are cooled and condensed by cooling element I! of the primary refrigeration system. The parts of the primary refrigeration system shown in Fig. 5 and similar to those shown in Fig. 1 are designated by the same reference numerals.

In Fig. 5 the structure for returning volatile fluid to the evaporators 36b at a higher level includes a first accumulation vessel Mb. The lower end of condenser 35b is connected to the upper part of vessel 4| b by a U-shaped conduit 42b which also includes a second U-shaped liquid trap 6!. Within vessel 4lb is disposed a vertical conduit 50b having a coil 5Ib at the lower end thereof. The lower end of coil 5| b is connected by a conduit 52b and liquid trap 53b to vaporizer 45b. The upper part of vaporizer 45b is connected by a conduit 54b to the upper end of vertical conduit 56b.

The lower part of accumulation vessel 4|b is connected by a conduit 62'to the upper part of V The lower part of vessel 63 is connected by a conduit 64 to the lower end of a vaporizer 65. Thevaporizer 65 may be heated-in any suitable manner, and, as shown in Fig. 5, is. arranged to be heated by I heat rejected by absorber I3b.

The absorber 43b may be connected in the primary refrigeration system in the manner illustrated in Fig. 1 and is diagrammatically shown as a looped coil. The vaporizer 65 is also diagrammatically shown as a looped coil extending through absorber.l3b. The absorber l3b is provided with cooling fins 24b for air cooling.

The upper end of vaporizer 65 is connected by a vertical conduit 66 to the lower end of conduit 40b. This connection at 61. is above the upper end of condenser 35b'of the heat transfer system. The conduit 66 is in heat exchange relation with the left-hand leg of U-shaped conduit 42 h.

The upper part of the'accumulation vessel 63 is connected by a conduit 68 to the lower end of conduit 40b and above the condenser 35b. The upper part of vessel 4 lb is connected by a conduit 55b to conduit 52b. At the point where the lower end of coil 51b is connected to conduit 52b the latter joins the lower end of conduit 56b. The upper end of conduit 56b is connected at 69 to the upper part of vertical conduit 66 and above the region where it is in heat exchange relation with the left-hand leg of U-shaped conduit 42b.

When the evaporators 36b are filled with liquid. evaporation of volatile fluid takes place. therein and condensation of the vapors is effected in condenser 35b. The condensate flows from condenser 35b through liquid trap 6i and U-shaped conduit 421; into the upper part oi? accumulation vessel 4"). When the liquid level in vessel 4|b reaches the upper connection of conduit 55b, liquid overflows through this conduit and thence through conduit 52b and liquid trap 53b into vaporizer 45b.

The liquid entering vaporizer 45b is vaporized therein and the vapors flow through conduit 54b into vertical conduit 56b and coil 5"). As in the modification of Fig. 4, condensation of vapors takes place in these parts thereby giving up heat to liquid in vessel 4 I b. The condensate flows from coil Bib and returns to vaporizer 45b through conduit 52b and liquid trap 53b. With heating of liquid in vessel 4| b liquid evaporates and the vapor pressure above the liquid surface builds up. With increase in such vapor pressure liquid is forced downwardly in vessel 4; and upwardly through conduit 62.into the upper part of the second accumulation vessel 63 which is located outside the thermally insulated space I 8.

Liquid flows from vessel 63 through conduit 64 into vaporizer 65. In vaporizer liquid is vaporized by heat rejected from absorber I 3b of the primary refrigeration system. The heating effected by absorber l3b results from the heat liberated with absorption of refrigerant vapor into absorption liquid in the primary refrigeration duits 40b anld 460 into the several condensers 59 in which it is condensed. The condensate flows from the condensers through liquid trap 66 into the receivers 38b of evaporators 36b.

By providing the additional liquid trap 6| in U-shaped conduit42b and arranging the lefthand leg of the latter in heat exchange relation with conduit 66, condenser 35b is filled with liquid during the periods when vaporized fluid is being returned to the higher level. Due to thermal contact between conduit 66 and the left-hand leg of U-shaped conduit 42b, liquid in the latter is heated and the pressure in this leg becomes approximately the same as the vapor pressure in vessel b. The pressure in the left-hand leg of U -shaped conduit 42b acts on liquid in the left- -hand leg of liquid trap 6i and is effective to keep condenser 35b filled with. condensate or liquid.

By keeping condenser 35b filled with liquid, this condenser is rendered inoperative and condensation of vapors is effected in condensers 59.

During the above described portion of theoperation, the liquid level falls in vessel 4Ib due to forcing of-liquid into vessel 63. vAs in the modification of Fig. 4, less and less ofcoil 5lb is immersed in liquid with lowering of the liquid level,

whereby less and less condensation of vapors takes place in the coil. This results in an increase in the pressure existing in the vaporization-condensation circuit, and, when this pressure increases sufliciently, the liquid trap formed by the lower end of coil Iib, conduit 51b, and conduit lib is forced open. When this occurs vapors in coil lib can flow through conduit lib'into the upper part of vessel lib. With the forcing open of this liquid trap, liquid, rises in conduit 56b. The vapor pressure in vessel lib now becomes suillciently great to force the remaining liquid in this vessel through conduit 62 into vessel 63.

With all of the liquid rcmov from vessel lib a path of flow is provided for the vapors through conduit 02 into accumulation vessel 63. The vapor entering vessel 63 through conduit 62 is conducted through conduit 88 into the lower end of conduit llb. When this occurs the liquid in condenser llb falls and flows into vessel lib. This renders condenser 35b operative again and vapor flowing upward in conduit 66 is now condensed in the condenser. Liquid in conduit 56b flows into vaporizer lib and vaporizes therein. This vapor is condensed in condenser 35b and returns to accumulation vessel lib.

With vaporizer 65 no longer containing liquid and-vaporizer 45b also being empty, for returning vaporized fluid to the evaporators is terminated, and, since condenser 35b is again operative to condense vapor in the heat transfer system, evaporation of liquid is resumed in evaporators 36b. The pressure in the heat transfer system is now equalized, the pressure being determined by the low temperature of condenser 35b.

In Fig. 6 is diagrammatically illustrated another manner of connecting a plurality of evaporators in a heat transfer system of the character shown in Fig. andjust described. In place of a number of condensers each connected to a separate evaporator, as shown in Fig.. 5, a single condenser Sla is employed in Fig. 6. The upper end of condenser 59;; is connected by a vertical conduit lild to the upper end of the condenser of the heat transfer system, as in the modification of Fig. 5. The lower end of condenser 59a is connected by a conduit iii to a horizontal conduit ii to which is connected a first group of evaporators lie. The evaporators 360 are of the flooded type and include a receiver 38c and a looped coil 39c. The lower end of conduit I0 is provided with a liquid trap 12 which is connected by a vertical conduit 13 to another horizontal conduit ll to which is connected a second group of evaporators "c. The lower end of conduit 13 is provided with a liquid trap 15 which is connected by a conduit ll to a horizontal conduit 11 having a third group of evaporators llc connected thereto.

A liquid trap 18 at the lower end of conduit 16 is connected by a conduit 19 to a horizontal conduit Bil having a fourth group of evaporators 360 connected thereto. The upper parts of liquid traps l2, l5, and I8 are connected by conduits ll, l2, and 83, respectively, to vertical conduit lld. 'The lower end of conduit ll is also connected to conduit liid by a conduit ll.

When the condenser of the heat transfer system is filled with liquid and rendered inoperative, vaporous volatile fluid will flow. upwardly in conduit lld, as explained above in connection with the modification of Fig. 5. During this period of the operation of the system, condensation of vapors takes place in condenser 59a.

The condensate formed in condenser 59a flows the period Figs. 2, 3, and

through conduit 10 into horizontal conduit 1i and fills up the evaporators lie at the highest level. When these evaporators are filled with liquid, liquid overflows from trap 12 into vertical conduit 13 whereby the evaporators connected to conduit H are next filled with liquid. In this manner each group of evaporators is filled with liquid until liquid flows into the evaporators 36c at the lowest level.

When the condenser of the heat transfer system is no longer filled with liquid and again rendered operative, evaporation of liquid takes place in the evaporators 36c. Thevapors formed in evaporators 36c flow' through conduits ll, 82, 83, and 8l into vertical conduit lid, and thence into the condenser of the heat transfer system. The vapors are condensed in the condenser and the liquid condensate flows into an accumulation vessel, as in the modification of Fig. 5, until sufllcient liquid is accumulated whereby volatile fluid is again returned to the evaporators at the higher level.

The heat transfer systems of Figs. 2, 3, and 4 may be provided with a plurality of evaporators connected in series or parallel or in any other suitable manner. The evaporators may be arranged in the same manner as shown in Fig. 6, for example, with a collection vessel employed in place of the condenser 59a.

The several groups of evaporators in Fig. 6 may be located in different floors of a building. The modifications of Figs, 5 and 6 possess an advantage overthe systems of Figs. 2, 3, and 4 where volatile fluid is returned from a lower level through a relatively great height to one or a plurality of evaporators at a higher level. In

4 liquid in the riser conduits returns to the accumulation vessel at the end of a liquid lifting period. Such return flow of liquid is avoided in the heat transfer systems of Figs. 5 and 6.

While several embodiments of the invention have been shown and described, such variations and modifications are contemplated as fall within the true spirit and scope of the invention, as pointed out in the following claims.

What is claimed is: d

l. A method of heat transfer which includes simultaneously vaporizing liquid at a place of evaporation at an upper elevation and condensing vaporized fluid in a place of condensation at a lower elevation, collecting condensate at a place of accumulation, and intermittently stopping such vaporization of liquid and condensation of fluid and raising liquid condensate to said place of evaporation by trapping vapor above a surface level of accumulated condensate to exert force thereon, and thereafter releasing such trapped vapor to said place of condensation to terminate the raising of liquid condensate to said place of evaporation.

2. A method of heat transfer which includes vaporizing liquid in a place of evaporation at an upper elevation, condensing vaporized fluid in a place of condensation at a lower elevation, collecting condensate in a place of accumulation, stopping such vaporization of liquid and condensation of fluid and raising liquid condensate to said place of evaporation by trapping vapor abovea surface levelof condensate to exert forcecondensation of fluid in said places of evaporation and condensation, respectively, by releasing such trapped vapor to said place of condensation. 3. A method of heat transfer which includes simultaneously vaporizing liquid in a place of evaporation at an upper level and condensing vaporized fluid in. a first place of condensation at a lower level, intermittently vaporizing condensate in a place of vaporization, flowing such vaporized condensate into a second place of condensation at a level above the place of vaporization, conducting liquid from the second place of condensation into the place of-evaporation, and permitting condensation of vaporized condensate in the second place of condensation by filling the first place of condensation with liquid so that vaporized fluid will not be condensed therein.

4. A method of heat transfer which includes simultaneously vaporizing liquid in a first place of vaporization at an upper elevation and condensing vaporized fluid in a place of condensation at a lower elevation, intermittently stopping such vaporization of liquid and condensationof fluid and raising condensate between said elevations by conducting condensate to a place of accumulation, conducting condensateto a second place of vaporization when a predetermined quantity of condensate has accumulated at the place of'accumulation, trapping vapor formed at the second place of vaporization above a surface level of liquid condensate in the place of accumulation to exert force thereon to raise condensatebetween said elevations, and subsequently releasing. the trapped vapor to the place of Y condensation to terminate the raising of condensate between said elevations.

5. A method of heat transfer which includes simultaneously vaporizing liquid 'in a place of evaporation at an upper elevation and condensing vaporized fluid in a place of condensation at a lower elevation, conducting liquid from the place of condensation to a place of accumulation, intermittently stopping such vaporization of liquid and condensation of fluid and raising liquid between said elevations and through the place of condensation by trapping vapor above a surface level of liquid in the place of accumulation to exert force thereon, and terminating such raising of liquid by releasing trapped vapor to the place of condensation.

6. A method of heat transfer which includes simultaneouslyvaporizing volatile liquid in a place of evaporation at an upper elevation and condensing vaporized fluid in a. place of condensation at, a lower elevation, conducting liquid condensate from the place of condensation to a place of accumulation, intermittently stopping such vaporization of liquid and condensation of fluid and raising liquid to the place ofevaporation by trapp ng vapor above a surface level of liquid in the place of accumulation to exert force thereon and subsequently releasing such trapped vapor to said place of condensation to terminate the raising of liquid to the place of evaporation, and heating liquid in the place of accumulation to form the trapped vapor.

'1'. In the art of heat transfer in which volatile liquid is vaporized in a place ofevaporation and vaporized fluid is condensed in a place of con-' densation, such vaporization of liquid and condensation of vaporized fluid being effected at substantially the same pressure, the improvement which consists incollecting liquid condensate in a place ofaccumulation, and returning liquid from the place of accumulation to the place of evaporation and stopp ng the vaporization of liquid and condensation of fluid in the places of evaporation and condensation, respectively, by keeping the place of condensation filled with liquid.

8. In the art of heat transfer in which volatile liquid is vaporized in a place of evaporation and vaporized fluid is condensed in a place of condensation, the improvement which consists in stopping such vaporization of liquid and condensation of fluid and returning liquid to the place of evaporation by collecting liquid condensate in a place of accumulation, flowing liquid from the place of accumulation to a place of vaporization, trapping vapor formed in the place of vaporization above a surface level of liquid at the place of accumulation to exert force thereon to cause fall of liquid level, and subsequently releasing the trapped vapor from the place of accumulation to stop the return of liquid to the place of evaporation and to allow liquid condensate to collect again in the place of accumulation.

9. In the art ofheat transfer in which liquid is vaporized in a place of evaporation and va-.

porized fluid is condensed in a place of condensation, the improvement which consists in re-.

turning liquid to the place of evaporation by collecting liquid condensate in a place of accumulation, intermittently sip q dom the place of accumulation to a place of vaporization, v

and trapping vapor formed in the place of vaporization above a surface level of liquid at the place of accumulation to exert force thereon to cause fall of liquid level, and subsequently releasing the trapped vapor from said place of accumulation to permit rise of liquid level in the vplace of accumulation.

10. Refrigeration apparatus including'a heat receiving part and a cooling element, a heat transfer circuit partly filled with avolatile liquid and including an evaporator in .which. liquid is vaporized and a condenser in which vapors are condensed, said condenser being in heat exchange relation with said cooling element, a vessel con nected to receive condensate from said condenser,

means associated with said circuit to return con- .densate from said vessel through said condenser to said evaporator and including a niember in Q thermal exchange relationwith said heat receiving part, and a heater for heating said part.-

11. A heat transfer system including a circuit partly fllled with a volatile liquid and including an evaporator in which liquid is vaporized and a first condenser in'which vaporized fluid is condensed, an accumulator connected to receive liquid from said first condenser, and structure to return liquid from said accumulator to said evaporator including a vaporizer into which liquid is conducted from said accumulator, a second condenser above said evaporator connected to receive vaporized fluid formed in said vaporizer, said second condenser being connected to conduct liquid to said evaporator, and means to prevent liquid from flowing from said first condenser to said accumulator while liquid is vaporizing in said vaporizer and vaporized fluid is condensing in said second condenser.

12. A method of transferring heat which includes vaporizing liquid in a place of vaporization, flowing to a place of condensation substantially all of the vaporized fluid formed in the place of vaporization, condensing the vaporized fluid in the place of condensatiomfiowing condensate by gravity from said place of condensation to a place of accumulation, and vaporizing ,uid, condensate to exert place of condensation,

a part of said condensate to cause flow of liquid from the place of accumulationthrough the.

place of condensation to the place of vaporiaation.

13. In the art of transferring heat'with the aid of a system having a place of vaporization in which liquid is vaporized and a place of condensation connected to receive substantially all of the vaporized fluid formed in-the place of vaporization and in which the vaporized fluid is con-.

densed, the improvement which consists in flowing condensate by gravityfrom the place of condensation to a place of accumulation, and utilizhas accumulated in the place of accumulation,

ing vapor in the system'to cause condensate to flow from the place of accumulation through the place of'condensation to the place of vaporization. a i 14. In a heat transfer systemincluding a circuit for heat transfer fluid having an evaporator at an upper elevation in which fluid is'vaporized and a condenser at a lower elevation in which is liquefied substantially all of the vaporized fluid formed in the evaporator, a vessel for accumulating liquid below the condenser, a conduit from the lower part of said vessel to the evaporator at the upper elevation, said conduit including the condenser, and means for intermittently trapping vapor above the surface level of liquid in said vessel to cause alternate upward flow of liquid in said conduit from said vessel and downward flow of condensate said vessel.

15. A method of heat transfer which includes simultaneously vaporizing volatile liquid in, a

from the condenser into place of evaporation and condensing vaporized fluid in a place of condensation, flowing liquid condensate from the place of condensation to a place of accumulation in a path of flow which always provides for unrestricted flow of liquid therethrough, and intermittently returning liq- I uid to said place of evaporation by first trapping above a surface level of accumulatedliq- I force thereon andsubsequently releasing such trapped vapor to said the trapped vapor being vapor trapping vapor .formed in the second, place ,of vaporization above a surfacelevel-of liquid condensate at the place-of accumulation to exert .iorce thereon to return, condensate'to the first place of vaporization, and subsequently releasing the trapped vapor to the place ofcondensation;"

l 18. In a method of transferring heat with the 1 aid of a system in which all places are always in unobstructed fluidcommunlcation with each other andlin which heat is transferred by vaporizing liquid at a, high temperature plac'e of vaporization, flowing vapor from, such place of vaporization to a place of condensation where heat is rejected,'and condensing vapor at the place of condensation, steps of, supplying a limited quantity of liquid to said place of vaporization, forcing condensate to a"lower temperature place of vaporization upon increase in pressure in said hightemperature place of vaporization resulting from vaporization of liquid therein, flowing vapor from the lower temperature place of vaporization to. the place of condensation afterthe hightemperature place of 'vaporizationis depleted of liquid, condensing the last mentioned vapor and withholding the liquid condensate from both the high and lower temperature places of vaporization, andagain supplying a limited quantity of liquid to the high temperature place of vaporization upon increase in liquid level of the withheld condensate. a

19. A heat transfer system comprising a vaporization condensation circuit partly filled with avolatile liquid and including low and higher temperature evaporation members and a condensation member, liquid holding means in said circult to withhold liquid condensate from both of said evaporation members and operative to supply a quantity of liquid to said higher temperature evaporation member upon rise in liquid level in said liquid holding means, and said low'tem-' perature evaporation member being connected to segregated by liquid condensate from said place a such trapped vapor by conducting condensate to receive liquid from said liquid holding means in a path of flow including said condensation member upon increase in pressure in said highertemrperature evaporation member resulting fro evaporation of liquid therein. 7 20. A vaporization-condensation heat transfer circuit containing a volatile fluid and having two i portions in fluid communication each provided with a vaporization part, said circuit including a.

, condensation part for condensing therein vaporphase to flow alternately to said portions, said a place of vaporization in communication with the place of accumulation, and releasing the trapped vapor to the place of condensation after returning liquid to the place of evaporation, the trapped vapor being segregated by liquid from the place of condensation, before being released thereto. r

17. A method or heat transfer which includes simultaneously vaporizing volatile liquid in a flrst place of vaporization'and condensing vaporized fluid in a place of condensation, intermittently returning condensate to the first place of vapor ization by conducting liquid condensate from the place of condensation to a placeof accumulation in a path of flow which always provides for unrestricted flow of liquid therethrough, conducting condensate to a second place of vaporization ized fluid formed in both of said vaporization parts, and structure for causing fluid in liquid structure being so constructed and r.rranged that when liquid flows to one of said portions such liquid passes through the condensationpart of said heat'transfer circuit.

21. Ina heat transfer system with a volatile liquid, said circuit including a first evaporation member and a condensation member forming afirst portion and a second evaporation member and said condensation member forming a second portion in fluid communication with said first portion, said condensation member being capable of condensing therein vaporized fluid formed in said first, and second vaporizationmembers, and structures embodied in said circuit for causing flow of liquid alternately to said portions, said structure being so constructed and arranged that liquid flowing to one of said portions passes through said condensation member.

when a predetermined quantity of condensate comprising a vaporization-condensation circuit partly filled 22. A method of heat transfer which includes simultaneously vaporizing volatile liquid in a place of evaporation arid condensing vaporized fluid in a place of condensation, conducting liquid condensate from the place of condensation to a place of accumulation, intermittently stopping such vaporization of liquid and condensation of fluid and returning liquid to the place of evaporation by trapping vapor above a surface level of liquid in the place of accumulation to exert force thereon and subsequently releasing such trapped vapor to said place of condensation, and forming the trapped vapor in the place of accumulation by heating liquid therein by heat derived from vapors formed in a place of vaporization to which liquid condensate is conducted.

23. In the art of heat transfer in which volatile liquid is vaporized in a place of evaporation and vaporized fluid is condensed in a place of condensation, the improvement which consists in stopping such vaporization of liquid and condensation of fluid and returning liquid to the place of evaporation by collecting liquid condensate in a place of accumulation, flowing liquid from the place of accumulation to a'place of vaporization, trapping vapor formed in the place of vaporization above the surface level of liquid at the place of accumulation to exert force thereon to cause fall of liquid level, and stopping the flow of liquid from the place of accumulation to the place of vaporization after the liquid level in the place of accumulation is depressed to a predetermined level by the trapped vapor.

. 24. Refrigeration apparatus including a heat transfer circuit partly filled with a volatile liquid and comprising a plurality of parts including an evaporator in which liquid is vaporized and a condenser connected to receive vaporized fluid from said evaporator and disposed below the lat ter, and a cooling element in heat exchange relation with said condenser to render the latter capable of liquefying vaporized fluid formed in said evaporator, said circuit being so constructed and arranged that said condenser is intermittently rendered ineffective to liquefy vaporized fluid formed in said evaporator and volatile liquid is introduced into said evaporator responsive to accumulation of liquid in one of said parts of said circuit. Y 25. A heat transfer system including a circuit partly filled with a volatile liquid and comprising a plurality of parts including an evaporator in which liquid is vaporized and a condenser connected to said evaporator and in which normally is liquefied substantially all of the vaporized fluid formed in the latter, such vaporization of liquid in said evaporator and condensation of vaporized fluid in'said condenser being effected at substantially the same pressure determined by the temperature of said condenser, said circuit being so constructed and arranged that said condenser is intermittently rendered ineffective and volatile liquid formed in said condenser is returned to in heat exchange relation with said condenser to render the latter capable of liquefying vaporized fluid formed in said evaporator, said condenser and said accumulator always being in un bstructed fluid communication with each other through said connection, and said circuit being so constructed and-arranged that volatile liquidis returned intermittently from said accumulator to said evaporator responsive to accumulation of liquid in said accumuiaton 27. A heat transfer system including a circuit partly filled with a volatile liquid and comprising a plurality of parts including an evaporator in which liquid is vaporized and a condenser connected to said evaporatorand in which'normally is liquefied substantially all of the vaporized fluid formed in the latter, such vaporization of liquid in said evaporator and condensation of vaporized fluid in said condenser being effected at substantially the same pressure determined by the temperature of said condenser, said circuit being so constructed and arranged that said condenser is intermittently rendered ineffective to cause the pressure in said circuit to increase sufliciently to stop vaporization of volatile liquid in said evaporator responsive to accumulation of liquid in one of said parts in said circuit, the arrangement and construction of said circuit further being such that when said condenser is rendered ineffective volatile liquid is introduced into said evaporator.

28. A heat transfer system partly filled with a volatile liquid and comprising a plurality of parts all of which are in unobstructed fluid communication, said parts including a vaporizer in which liquid is vaporized and a condenser connected to said vaporizer and in which normally is liquefled substantially all of the vaporized fluid formed in the latter, the heat resulting from liquefaction of vaporized fluid in said condenser being rejected to a medium in thermal conductive relation therewith, said circuit being so constructed and arranged that only intermittent flow of fluid from said vaporizer to said condenser is 'eflected during operation of the system responsive to accumulation of liquid in one of said parts of said circuit, and the arrangement and construction of said circuit further being such that intermittent flow of fluid from said vaporizer to said condenser is efiected even when said vaporizer is partly filled with liquid.

ERIK SIGFRID LYNGER.

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