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Publication numberUS3760602 A
Publication typeGrant
Publication dateSep 25, 1973
Filing dateJul 5, 1972
Priority dateJun 28, 1971
Publication numberUS 3760602 A, US 3760602A, US-A-3760602, US3760602 A, US3760602A
InventorsP Blomberg
Original AssigneeElectrolux Ab
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Tiltable air-cooled absorption refrigeration apparatus of the inert gas type
US 3760602 A
Abstract
Absorption refrigeration apparatus of the inert gas type which, when it is operating to produce useful refrigeration, can be inclined to the vertical. This is accomplished by employing an evaporator having a part providing a horizontally extending passageway and conducting liquid refrigerant to the opposing ends of such evaporator part from a condenser through conduit means. The conduit means is so constructed and arranged that liquid refrigerant will flow therethrough from the condenser to whichever end of the evaporator part that is at the higher level when the apparatus is inclined to the vertical.
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United States Patent [191 Blomberg [451 Sept. 25, 1973 1 TILTABLE AIR-COOLED ABSORPTION REFRIGERATION APPARATUS OF THE INERT GAS TYPE [75] Inventor: Peter Erik Blomberg, Stockholm,

[21] Appl. No.: 269,158

[30] Foreign Application Priority Data UNITED STATES PATENTS 2/1943 ,Blomquist 62/491 X 2,395,392 2/1946 Brace 62/492 X 2,407,733 9/1946 Ashby 62/492 X 2,566,171 8/1951 Coons 62/491 X 2,631,443 3/1953 Backstrom 62/490 X 3,063,257 1 1/1962 Phillips et a1. 62/490 X Primary ExaminerWilliam ODea Assistant ExaminerPeter D. Ferguson Attorney-Edmund A. Fenander 5 7] ABSTRACT Absorption refrigeration apparatus of the inert gas type which, when it is operating to produce useful refrigeration, can be inclined to the vertical. This is accomplished by employing an evaporator having a part providing a horizontally extending passageway and conducting liquid refrigerant to the opposing ends of such evaporator part from a condenser through conduit means. The conduit means is so constructed and arranged that liquid refrigerant will flow therethrough from the condenser to whichever end of the evaporator part that is at the higher level when the apparatus is inclined to the vertical.

15 Claims, 6 Drawing Figures PATENTEU SEP25 I973 sum we TILTABLE AIR-COOLED ABSORPTION REFRIGERATION APPARATUS OF THE INERT GAS TYPE BACKGROUND OF THE INVENTION level and in which, due to evaporation and diffusion thereof into an inert gas, a refrigerating effect is produced. The evaporator forms a part of an inert gas circuit which includes an absorber at a still lower level and in which refrigerant vapor is absorbed into absorption liquid.

The evaporator is arranged to effect cooling of a thermally insulated compartment of a cabinet while other components of the refrigeration apparatus are disposed in a vertically extending apparatus space at the rear of the cabinet between the lateral sides thereof. Natural draft is produced in the apparatus space and causes upward circulation of ambient air due to heat radiated by the absorber and condenser, so that surrounding cool air can flow over their surfaces and assure adequate cooling of these parts.

2. Description of the Prior Art In absorption refrigeration apparatus of the type under consideration the vertical location and size of the components and their positions relative to one another in the apparatus space and thermally insulated interior of the refrigerator cabinet is dependent in part by the limited height available which is determined by the vertical height of the cabinet with which the refrigeration apparatus is associated.

For effectively air cooling the condenser the pipes thereof are distributed over the entire cross-sectional area of the apparatus space between the lateral sides of the cabinet. For this reason it has been the practice to employ lengths of piping for the condenser which are relatively long and extend across the rear of the refrigerator cabinet from one side to the opposite side thereof. This practice has been more or less dictated because the height of the cabinet determines the height of the apparatus space which prohibits the condenser piping from being inclined downward to any great extent to promote downward gravity flow of liquid.

It also has been the practice to provide evaporators formed of relatively long lengths of piping having several sections or components which are at a small inclination to promote gravity flow of liquid refrigerant in the presence of inert gas. Such relatively long lengths of evaporator piping are necessary to provide adequate gas and liquid contact surface to insure optimum cooling for refrigeration apparatus of a given capacity. And the small inclination of such evaporator piping also is dictated by the height of the cabinet and prohibits such piping from being inclined downward to any great extent.

With absorption refrigeration apparatus having components of the kind just described, the cabinet associated with such apparatus must be supported in a horizontal position to make certain that the apparatus will operate correctly and produce useful refrigeration. This is so because of the tendency of the refrigeration apparatus to malfunction when it is tilted from the vertical to the slightest degree. Such malfunctioning of the apparatus often occurs when the normal circulation of fluids in the apparatus stops which can be caused, for example, by the building up of liquid bodies that block the flow of inert gas.

Heretofore, it has been a recognized rule that only a maximum inclination of the cabinet of not more than l.7 can be tolerated. Within this range refrigeration apparatus of the'inert gas type has functioned in a satisfactory manner in permanent structures such as dwellings and buildings, for example. In recent years the need has grown to provide absorption refrigeration apparatus for boats, campers and travel trailers which can be operated by liquid or gaseous fuel when a source of electrical supply is not available. But since the maximum inclination of refrigeration apparatus that can be tolerated has not changed, this means that refrigeration apparatus provided on boats and travel trailers and the like, which often are not substantially upright or erect, will malfunction and cease to produce useful refrigeration which is objectionable.

SUMMARY OF THE INVENTION It is an object of my invention to provide an improved evaporator or cooling unit for absorption refrigeration apparatus which, when the apparatus is operating to produce useful refrigeration, can be tilted rearward and forward from an upright position and also from side to side at angles larger than heretofore possible.

Anotherobject is to provide such an improved evaporator or cooling unit for tiltable absorption refrigeration apparatus which is capable of producing useful refrigeration when installed in boats subject to rolling and in mobile camper and trailer vehicles which assume different angular positions when they are parked and when being moved from place to place.

I accomplish this by employing an evaporator having a part providing a horizontally extending passageway and conducting liquid refrigerant to the opposing ends of such evaporator part from a source of liquid refrigerant by conduit means. The conduit means is so constructed and arranged that liquid refrigerant will flow therethrough from the source to whichever end of the evaporator part that is at the higher level when the apparatus is inclined to the vertical.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side view, in section, of a refrigerator and air-cooled absorption refrigeration apparatus of the inert gas type associated therewith which embodies my invention; I

FIG. 2 is a rear elevational view, partly broken away and in section, of the refrigerator shown in FIG. 1;

FIG. 3 is a fragmentary perspective view of the evaporator structure of the refrigeration apparatus shown in FIG. 1 illustrating the positions the parts assume when the refrigerator is in a normal upright position;

FIG. 4 is a fragmentary perspective view similar to FIG. 3 illustrating the positions the parts assume when the refrigerator is tilted and inclined to the vertical; and

FIGS. 5 and 6 are fragmentary views of parts similar to those shown in FIGS. 2, 3 and 4 illustrating modifica- -tions of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, I have shown my invention in connection with a refrigerator comprising a cabinet having an inner liner 11 arranged to be supported within an outer shell 12 and insulated therefrom at 14 in any suitable manner. The inner liner 11 defines a thermally insulated compartment 15 to which access is afforded at a front opening adapted to be closed by an insulated door 16 hinged in any suitable manner (not shown) at the front of the refrigerator cabinet 10.

The cabinet 10 also includes an inner liner 17 which is enveloped in part by the insulation 14 and defines a top freezer compartment 18 into which access is afforded by a hinged door 19 within the upper part of the storage compartment 15. The compartment 15 defines a food space for storing foods at a higher temperature than in the freezer compartment 18 and preferably at a temperature above 32. The freezer compartment 18 is arranged to be cooled by an evaporator section 20a which is heat conductively associated with the inner liner 17 and the food storage compartment 15 is arranged to be cooled by an evaporator section 20b.

The evaporator sections 20a and 20b form the evaporator structure or cooling unit of absorption refrigeration apparatus of the inert gas type which comprises a generator 21 containing a refrigerant, such as ammonia, in solution in a body of absorption liquid, such as water. As shown in FIG. 2, heat is supplied to the generator 21 from a heating tube 22 which may be heated by an electrical heating element 23, for example, which is disposed within the tube and connected by conductors 24 to a source of electrical supply. The heat supplied to the generator 21 and absorption solution therein expels refrigerant vapor out of solution, and, in a manner to be described hereinafter, refrigerant vapor passes upward from the generator through a vapor supply line or conduit 25 and rectifier 26 into an air-cooled condenser 27 in which the vapor is liquefied by surrounding cool air which flows in physical contact therewith. In a manner that will be described hereinafter, the liquefied refrigerant flows from the condenser 27 into the evaporator section 20a in a path of flow which includes a conduit 28.

The evaporator sections 20a and 20b form the upper and intermediate horizontally extending parts, respectively, of an outer looped coil 30 having a first bend 31 therebetween. The outer coil 30 also includes a lower horizontally extending part 32 connected at its upper end by a second bend 33 to the intermediate part 20b and at its lower end at 34 to a pipe section 35 which forms a lower extension of the outer coil. The lower part 32 of the outer coil and pipe section 35 connected thereto at 34 form the outer passageway of a gas heat exchanger.

An inner looped pipe 36 extends lengthwise within the outer looped coil 30 and pipe section 35. Hence, the inner pipe 36 forms the inner passageway of the gas heat exchanger, the outer passageway of which is formed by the lower part 32 of the outer coil 30 and the pipe section 35. The inner pipe 36 also is formed with bends at the vicinities of the bends 31 and 33 of the outer looped coil 30.

The liquefied refrigerant evaporates and diffuses into an inert pressure equalizing gas, such as hydrogen, which flows upward through the inner looped coil 36 and passes from the upper open end 36a thereof into the presence of the refrigerant. In FIG. 3 it will be seen that the upper open end 36a of the inner coil 36 is at the closed end 30a of the outer looped coil 30. Due to evaporation of refrigerant into inert gas in the evaporator sections 200 and 20b, a refrigerating effect is produced with consequent absorption of heat from the surroundings.

The rich gas mixture of refrigerant and inert gas formed in the evaporator sections 20a and 20b, that is, the annular passageway between the upper and intermediate sections of the outer looped coil 30 and the inner coil 36 extending therethrough, flows downward therefrom through the coil bends and the outer passageway of the gas heat exchanger formed by the lower part 32 of the outer coil 30 and the pipe section 35.

As best shown in FIG. 2, the rich gas, together with any unevaporated refrigerant, flows from the gas heat exchanger through a conduit 37 into an absorber comprising a vessel 38 and a looped coil 39. In the absorber vessel 38 and looped coil 39 refrigerant vapor is absorbed into liquid absorbent, such as water, which enters through a conduit 40. The hydrogen or inert gas, which is practically insoluble and weak in refrigerant, is returned to the upper closed end 30a of the evaporator section 20a from the upper end of the absorber coil 39 through the inner pipe coil 36, the lower part of which forms the inner passageway of the gas heat exchanger and the upper part of which forms the inner passageways of the evaporator sections 20a and 20b.

Inert gas passing from the open end 36a of the inner coil 36 flows through upper evaporator section 20a in the presence of liquid refrigerant which is introduced therein through conduit 28 in a manner described he reinafter. Unevaporated liquid refrigerant is conducted from evaporator section 20a to evaporator section 20b for flow therethrough. Such liquid refrigerant flows in the presence of and in parallel flow with inert gas in evaporator section 20b.

Since inert gas weak in refrigerant first flows through evaporator section 200 and thereafter flows through evaporator section 20b, the gas in the upper evaporator section 20a contains a lesser amount of refrigerant vapor than the gas in the lower evaporator section 20b. The partial vapor pressure of the refrigerant is a gradient, so that the temperature in the evaporator sections also is a gradient, the evaporating temperature of liquid refrigerant being lower in the upper evaporator section 20a which constitutes the freezing portion of the evaporator or cooling unit.

The refrigerating effect produced by the upper evaporator section 20a, which is adapted to be operated at temperatures below freezing, it utilized to effect cooling of the upper compartment 18. The refrigerating effect produced by the lower evaporator section 20b, which is adapted to be operated at a higher temperature than that of evaporator section 20a, is utilized to cool air in the storage space 15.

Absorption liquid enriched in refrigerant in the absorber flows from the vessel 38 through the outer passageway 41a of an elongated liquid heat exchanger 41 which, within the generator 21, includes an outer vertical pipe 42 and an inner vertical pipe 43. Rich absorption liquid flows from the passageway 41a through a horizontal conduit 44 into a vertical standpipe 45. The conduit 44 is connected to standpipe 45 at a point 46 which is at a level below the liquid surface level 47 of the column of liquid in the pipe 45. As seen in FIG. 2, the liquid surface level 47 is at approximately the same level as the liquid surface level in the absorber vessel 38.

The extreme lower end of the pipe 45 is connected to the lower end of a pump pipe or vapor-liquid lift tube 48 heat conductively connected to the heating tube 19, as by welding 49, for example. Liquid is raised by vapor-liquid lift action through the tube or pump pipe 48 into the upper part of the pipe 43. The absorption liquid from which refrigerant vapor has been expelled flows downward by gravity through the inner pipe 43,

the latter extending through the liquid heat exchanger 41 and forming an inner passageway 41b thereof. The pipe 43 is connected to the conduit 40 from which weak absorption liquid overflows into the upper end of absorber coil 39.

The generator 21, together with a part of the liquid heat exchanger 41, are embedded in a body of insulation 50 retained in a metal shell or casing 51 having an opening 52a in the bottom 52 thereof. The electrical heating element 23, with the conductors 24 connected thereto, is arranged to be positioned within the heating tube 22 through the opening 52a in any suitable manner (not shown).

In the operation of the refrigeration apparatus, vapor generated in the vapor-liquid lift pump 48 flows from the upper end thereof to a gas separation chamber 43a at the extreme upper end of the standpipe 43 and passes through openings 43b in the side wall thereof into the outer passage 53 formed between the inner and outer pipes 43 and 42, respectively. The vapor in the passage 53 depresses the liquid level therein to a point 54 and flows through enriched absorption liquid in conduit 44 and pipe 45 by bubble action. After the generated vapor is analyzed in this manner in the conduit 44 and pipe 45, the refrigerant vapor passes from the upper part of the pipe 45, vapor supply line 25 and rectifier 26 to the condenser 27, as previously explained.

With the evaporator sections 20a and 20b positioned in the interior of the cabinet 10, the other components ofthe refrigeration apparatus are located in a vertically extending apparatus space 55 at the rear of the cabinet which is defined by the rear portions 12a of the lateral side walls of the outer shell 12 which project beyond the rear insulated wall 56. The top of the outer shell 12 extends rearward to the forward part of the apparatus space 48. Natural draft is produced in the space 55 and causes upward circulation of ambient air due to heat radiated by absorber vessel 38 and coil 39 and by the condenser 27, so that surrounding cool air can flow directly over their surfaces and assure adequate cooling of these parts or components. The top and bottom of the space 55 are open to enable air to flow freely upward therein.

As best shown in FIGS. 1 and 2, the gas heat exchanger, which is formed by the horizontal part 32 of the outer coil 30, extends across the cabinetlO between the lateral sides thereof and is disposed within a body of insulation 14a retained in a removable wall section 57 of the rear insulated wall 56 to facilitate the insertion of the evaporator sections 20a and 20b within the interior of the cabinet. The lower part of the gas heat exchanger, which is formed by the pipe section 35, projects rearwardly from the body of insulation 14a into the apparatus space 55. The removable wall section 57 closes an opening in the rear insulated wall 56 and is removably secured thereto in any suitable manner (not shown). As shown in FIG. 1, the inner liner 17 is enveloped in part by the body of insulation 14a retained in the removable wall section 57.

The condenser 27 comprises a horizontally extending U-shaped pipe 58 having spaced arms 59, one of which is shown in FIG. 2, and a connection 60 therebetween. Each of the arms 59 includes parts 61 and 62 having a bend 63 therebetween. The parts 61 and 62 of the arms 59 are provided with heat transfer members 63a, only a few of which are shown in FIG. 2.

The condensate conduit 28 is U-shaped and one leg thereof, which extends upward from its lowest part 28a, includes a first portion 65 and a second higher portion 66 which is fork-shaped and has a lower closed end and a pair of hollow elements 66a extending upward therefrom, as shown in FIG. 1. Each of the hollow elements 66a is connected to a different one of the outlets at the bends 63 of the arms 59.

Refrigerant vapor flows from the rectifier 26 to one arm 59 of the condenser at 67. The other arm 59 of the condenser 27 is connected by a conduit 68 to a part of the gas circuit, as to the pipe section 35, for example, so that any inert gas which may pass through the condenser 27 can flow to the gas circuit. In order to pre-cool liquid refrigerant before it flows into the presence of inert gas at the upper closed end 30a of the evaporator section 20a, the part 28a of the conduit 28 is heat conductively connected to the pipe section 35, another part 28b thereof is heat conductively connected to the lower part 32 of the coil 30, and a further part 28c is heat conductively connected at 69 to the intermediate part 20b of the coil 30.

In accordance with my invention, in order that the refrigeration apparatus can be tilted from an uprignt or erect position at angles substantially larger than heretofore possible without impairing its ability to produce useful refrigeration, liquid refrigerant from the condenser 27 is conducted through the conduit 28 to the opposing ends of the low temperature evaporator section 20a and is so constructed and arranged that liquid refrigerant will flow therethrough to whichever end of the evaporator section 200 that is at the higher level whenever the apparatus is tilted.

Referring to FIG. 3 it will be seen that the low temperature evaporator section 20a provides an elongated horizontally extending passageway having inlets 70 and -71 for liquid refrigerant at opposing ends thereof. In

FIG. 3, which illustrates the position of the low and higher temperature evaporator sections 20a and 20b when the refrigeration apparatus is in its normal upright or erect position, the low temperature evaporator section 20a slopes downward slightly from its closed end 30a to the bend 31 of the outer coil. A dotted horizontal line 72 in FIG. 3 clearly indicates the slight downward inclination of the low temperature evaporator section.

As described above, the part 28c of the liquid refrigerant supply conduit 28 is heat conductively connected at 69 to the high temperature evaporator section 20b, as by welding. The part of the liquid refrigerant conduit 28 extending from the condenser 27 may be referred to as a main conduit which, in the path of liquid flow, terminates at a fork 73. Two branch conduits 74 and 75, which may be referred to as supply lines, extend from the fork 73 to the liquid inlets 70 and 71, respectively. It will be seen that the liquid inlets 70 and 71 are located above the bottom of the low temperature evaporator section 20a so that liquid refrigerant cannot flow therefrom to the supply lines or branch conduits 74 and 75.

Each of the branch conduits 74 and 75 has a bend and a pair of arms extending therefrom. Thus, the branch conduit 74 has a bend 74a and arms 74b and 74c extending therefrom; and the branch conduit 75 has a bend 75a and arms 75b and 750 extending therefrom. The arm 74b extends from the fork 73 to the bend 74a which may be referred to as a region in the supply line 74; and the arm 740, which is longer than the arm 74b, extends from the region or bend 74a to the liquid inlet 70. In a similar manner the arm 75b extends from the fork 73 to the bend 75a which also may be referred to as a region in the supply line 75; and the arm 750, which is longer than the arm 75b, extends from the region or bend 75a to the liquid inlet 71.

While it may not be too apparent from the perspective view of FIG. 3, the arm 74b of the branch conduit 74 extends forward toward the viewer and the arm 74c extends rearward from the viewer so that the bend or region 740 and liquid inlet 70 are at opposite sides of a vertical plane which passes through the fork 73 and is parallel to the part 280 of the liquid refigerant conduit 28. In the same manner, the arm 75b of the branch conduit 75 extends forward toward the viewer and the arm 75c extends rearward from the viewer so that the bend or region 75a and liquid inlet 71 are at opposite sides of a vertical plane which passes through the fork 73 and is parallel to the part 28a of the liquid refrigerant conduit 28.

In FIG. 3, in which the low temperature evaporator section 20a is substantially horizontal and in the position it assumes when the refrigeration apparatus is in its normal upright or erect position, the liquid inlet 70 is at a higher level than the liquid inlet 71 and liquid refrigerant will flow through the branch conduit or supply line 74 from the fork 73 to the liquid inlet 70. FIG. 4 illustrates the position the low temperature evaporator section 20a assumes when the refrigeration apparatus is tilted or inclined in such a direction that the low temperature evaporator section slopes downward with respect to the dotted horizontal line 72 from the bend 31 of the coil 30 to the closed end 30a thereof. In FIG. 4 the liquid inlet 71 is at a higher level than the liquid inlet 70 and liquid refrigerant will flow through the branch conduit or supply line 75 from the fork 73 to the liquid inlet 71.

The reason that liquid refrigerant will flow through the branch conduit or supply line 74 in FIG. 3 to the higher located liquid inlet 70 is that, in this position of the low temperature evaporator section 20a, the bend or region 74a of the branch conduit 74 will be positioned lower than the bend or region 750 in the branch conduit 75. Hence, the highest point 74a in the branch conduit 74 is at a lower level than the highest point 75a in the branch conduit 75 and liquid refrigerant will flow to the higher located liquid inlet 70.

The reason that liquid refrigerant will flow through the branch conduit or supply line 75 in FIG. 4 to the higher located liquid inlet 71 is that, in the position of the low temperature evaporator section 20a, the bend or region 75a of the branch conduit 75 will be positioned lower than the bend or region 74a in the branch conduit 74. Hence, the highest point 75a in the branch conduit 75 is at a lower level than the highest point 74a in the branch conduit 74 and liquid refrigerant will flow to the higher located liquid inlet 71.

It now will be understood that the bend or region 74a of the branch conduit or supply line 74 moves upward from the position shown in FIG. 3 to the position shown in FIG. 4 when the refrigeration apparatus is inclined from its normal position in such a direction that the liquid inlet associated therewith moves downward. Further, the bend or region 74a moves downward from the position shown in FIG. 4 to the position shown in FIG. 3 when the refrigeration apparatus is inclined in such a direction toward its normal position that the liquid inlet 70 associated therewith moves upward.

In the same manner the bend or region 75a of the branch conduit or supply line 75 moves upward from the position shown in FIG. 4 to the position shown in FIG. 3 when the refrigeration apparatus is inclined in such a direction toward its normal position that the liquid inlet 71 associated therewith moves downward. Further, the bend or region 75a moves downward from the position shown in FIG. 3 to the position shown in FIG. 4 when the refrigeration apparatus is inclined in such a direction from its normal position that the liquid inlet 71 associated therewith moves upward.

It should be understood that the extent of upward movement of the bend or region in one of the branch conduits or supply lines 74,75 is substantially the same as the extent of downward movement of the bend or region in the other of the supply lines 75,74. Further, when liquid refrigerant is flowing through one of the supply lines 74,75 the flow of liquid refrigerant through the other of the supply lines 75,74 ceases and it becomes inactive.

When the liquid inlet 70 is higher than the liquid inlet 71, as shown in FIG. 3, liquid refrigerant will flow through the low temperature evaporator section 20a from the closed end 30a of the outer coil 30 toward the bend 31 thereof in the presence of inert gas. Unevaporated refrigerant passes from the low temperature evaporator section 20a through the bend 31 into the higher temperature evaporator section 20b and evaporates and difiuses into inert gas therein.

When the liquid inlet 71 is higher than the liquid inlet 70, as shown in FIG. 4, liquid refrigerant will flow through the low temperature evaporator section 20a from the liquid inlet 71 toward the closed end 30a of the coil 30 and evaporates and diffuses into inert gas therein. In FIG. 4 unevaporated refrigerant passes from the low temperature evaporator section 20a at 76 through a connection 77 and is introduced into the higher temperature evaporator section 20b at 78 for flow therethrough in the presence of inert gas. The connection 77 is formed with a trap 77a in which liquid can collect to form a liquid seal. It will be seen that liquid refrigerant from the connection 77 is introduced into the higher temperature evaporator section 20b at 78 which is below the liquid inlet 71 associated with the branch conduit or supply line 75.

When liquid refrigerant is introduced into the low temperature evaporator section 20a at the liquid inlet 70, as shown in FIG. 3, such liquid should not immediately flow from the low temperature evaporator section through the connection 77. To prevent this a dam 79 is provided at the bottom of the low temperature evaporator section 200 between the liquid inlet 70 and the region 76 at which the connection 77 is connected to the low temperature evaporator section. A dam 80 also can be provided at the opposite end of the low temperature evaporator section 20a between the liquid inlet 71 and the bend 31 of the outer coil 30 for the purpose of collecting some liquid refrigerant in the low temperature evaporator section 20a. This is especially desirable when the low temperature evaporator section 20a is almost horizontal. The liquid refrigerant retained in the low temperature evaporator section 200 between the dams 79 and 80 can be used to produce useful refrigeration during the interval of time that passes when the low temperature evaporator section 20a shifts from one sloping position to an opposite sloping position.

In FIG. I have shown another embodiment of my invention in which parts having the same function as parts shown in FIGS. 1 to 4 are referred to by the same reference numerals with 100 added thereto. Further, it will be understood that parts of the refrigeration apparatus in the embodiment of FIG. 5 which are not shown are like those shown in FIGS. 1 and 2 and described above.

In FIG. 5 refrigerant vapor expelled from solution in the generator flows therefrom in a path of flow which includes a vapor supply line 125. A condenser 127, which includes straight sections 81 and 82 and a connecting bend 83 and is provided with heat transfer members 83a, receives refrigerant vapor from the supply line 125 at the condenser inlet 167. A vent conduit 168 connects the outlet end 127a of the condenser 127 to a part of the gas circuit, such as to the conduit 137, for example, to vent inert gas from the condenser to the gas circuit.

The evaporator includes a low temperature evaporator section 120a and a higher temperature evaporator section 120b. These evaporator sections and a gas heat exchanger 132 comprise an outer looped coil 131 within which extends an inner looped coil (not shown) which is similar to and like the inner looped coil 36 in the first described embodiment shown in FIGS. 1 to 4. The low temperature evaporator section 120a is formed with liquid inlets 170 and 171.

Liquid refrigerant formed in the condenser 127 flows through a U- shaped conduit 128 having a down leg 128d and an up leg which includes parts 128b, 1280 and 128e. The part 128b is heat conductively connected to the bottom straight portion 132 of the outer looped coil 130 forming the outer gas heat exchanger passageway. The part 128a is heat conductively connected to the higher temperature evaporator section 120b. The part 128e is heat conductively connected to the low temperature evaporator section 120a. The upper end of the up leg of conduit 128 is connected to the liquid inlet 170 of the low temperature evaporator section 120a.

Liquid refrigerant formed in the condenser 127 also can flow therefrom through a U-shaped conduit 84 having a down leg 84d and an up leg including parts 84b and 84c. The 84b is heat conductively connected to the bottom straight portion of the looped coil 130. The part 840 is heat conductively connected to the higher temperature evaporator section lb. The upper end of the up leg of conduit 84 is connected to the liquid inlet 171 of the low temperature evaporator section 120a. A

A conduit 125a, which extends downward from the condenser inlet 167 and forms an extension of the vapor supply line 125, is connected at its lower end at 85 to the down leg 128d of the U-shaped conduit 128.

When the refrigeration apparatus of FIG. 5 is inclined from its normal upright position and the bend 83 of the condenser 127 moves downward, liquid refrigerant formed in both straight sections 81 and 82 of the condenser will flow through the U-shaped conduit 84 and be discharged therefrom into the liquid inlet 171 which will be at a higher level than the liquid inlet 170. In such case liquid refrigerant will flow downward toward the closed end 130a of the low temperature evaporator section 120a in the presence of inert gas. Unevaporated liquid refrigerant will flow from the low temperature evaporator section 120a through the connection 177 into the higher temperature evaporator section 12% and flow therethrough in the presence of inert gas.

When the refrigeration apparatus of FIG. 5 is in its normal upright position and the condenser 127 and low comnection 177 having a liquid trap 177a is connected at its upper end at 176 to the low temperature evaporator section a and at its lower end at 178 to the higher temperature evaporator section 12Gb.

temperature evaporator section 1200 are substantially horizontal and inclined downward slightly in the manner illustrated in FIG. 3, liquid refrigerant formed in the bottom straight section 82 of the condenser 127 will flow toward the outlet end 127a of the condenser and thence enter the down leg 128d of the U-shaped conduit 128. Liquid refrigerant formed in the upper straight section 81 of the condenser will flow toward the refrigerant vapor inlet 167 thereof and continue flowing downward through conduit a into the down leg of the U-shaped conduit 128. The liquid refrigerant passing into the down leg of the conduit 128 in the manner just described is discharged from the up leg thereof into the liquid inlet 170 which will be at a higher level than the liquid inlet 171. When liquid refrigerant is supplied to the liquid inlet 170 which is at the higher level liquid refrigerant-will flow through the low and higher temperature evaporator sections 120a and 12% in the same manner as in the first described embodiment of FIGS. 1 to 4.

In the embodiments of FIGS. 1 to 4 and FIG. 5 the low temperature evaporator sections are almost horizontal while the higher temperature evaporator sections are inclined to the horizontal at an angle which is greater than the largest angle of inclination of the refrigeration apparatus that can be tolerated without adversely affecting the normal operation of the refrigeration apparatus. In accordance with my invention it is also possible to employ an evaporator or cooling unit in which both the low and higher temperature evaporator sections are about horizontal and such an embodiment is shown in FIG. 6 with parts similar to parts shown in FIGS. 1 to 4 referred to by the same reference numerals with 200 added thereto and with parts similar to parts shown in FIG. 5 referred to by the same reference numerals with 100 added thereto.

In FIG. 6 liquid refrigerant is conducted to a low temperature evaporator section 220a through a U-shaped conduit 228 having its down leg 228d connected to receive liquid refrigerant formed in a condenser (not shown) which may be like the condenser 27 shown in FIGS. 1 and 2 or like the condenser 127 shown in FIG. 5.

In FIG. ,6 the low and higher temperature evaporator sections 220a and 220b, each of which is substantially straight and provides an elongated passageway, are almost horizontal. Inert gas weak in refrigerant flows from an absorber (not shown) through a conduit 236 to one end of the low temperature evaporator section 220a into the presence of liquid refrigerant introduced therein. Inert gas partially enriched in refrigerant flows from the opposite end of the low temperature evaporator section 2200 through a conduit 231 to the higher temperature evaporator section 220b into the presence of liquid refrigerant. Inert gas enriched in refrigerant flows from the higher temperature evaporator section 220b through a conduit 237 to the absorber (not shown). The conduits 236 and 237 are shown in heat exchange relation and may form passageways of a gas heat exchanger like the gas heat exchanger 35 in the embodiment of FIGS. 1 to 4.

The lowest part 228a of the U-shaped conduit 228 is heat conductively connected to the higher temperature evaporator section 220b. The up leg of the U-shaped conduit 228, which includes a part 228b heat conductively connected to the conduit 231, is connected at its upper end at 86 to the low temperature evaporator section 220a.

Unevaporated refrigerant is conducted from the ends of the low temperature evaporator section 220a to the ends of the higher temperature evaporator section 220b by conduits 87 and 88. The upper end of conduit 87 is connected to one end 89 of the low temperature evaporator section 220 and the lower end thereof is connected to the oppositely located end 90 of the higher temperature evaporator section 220b. In a similar manner the upper end of conduit 88 is connected to one end 91 of the low temperature evaporator section 220a and the lower end thereof is connected to the oppositely located end 92 of the higher temperature evaporator section 220b.

Conduits 87 and 88 are formed with traps 87a and 88a in which liquid can collect to form liquid seals. Unevaporated refrigerant passes from the higher tempera ture evaporator section 220b through a conduit 93 to the gas circuit for flow to the absorber (not shown). The conduit 93, which has a trap 93a in which liquid can collect to form a liquid seal, has its upper end connected to the higher temperature evaporator section 220b at 94 and its lower end connected to the gas circuit at 95.

In the embodiment of FIG. 6 the low and higher temperature evaporator sections 220a and 220b are almost horizontal when the refrigeration apparatus is in its normal upright position. Even when the refrigeration apparatus is in its normal upright position the higher temperature evaporator section 220b desirably slopes downward slightly from the region 90 to the region 92, so that gravity flow of liquid refrigerant from right to left in FIG. 6 will be promoted.

As pointed out above liquid refrigerant is supplied from the condenser through U-shaped conduit 228 to the low temperature evaporator section 2204 intermediate the ends thereof at 86. When the refrigeration apparatus is inclined from its normal operating position and both of the low and higher temperature evaporator sections 220a and 2201; slope downward from right to left in FIG. 6, liquid refrigerant will flow downward through the left-hand part of the low temperature evaporator section 220a and evaporate and diffuse into weak inert gas flowing countercurrent thereto. The inert gas becomes partially enriched in refrigerant and flows from the right-hand end of the low temperature evaporator section 220a through conduit 231 into the higher temperature evaporator section 220b.

Unevaporated refrigerant passes from the low temperature evaporator section 220a into the upper end of conduit 87 at 89 and is discharged from the lower end thereof into the higher temperature evaporator section 220b at 90 which may be referred to as a liquid inlet that is at a higher level than the liquid inlet 92 since the higher temperature evaporator section slopes downward from right to left. The liquid refrigerant introduced at the liquid inlet 90 into the higher temperature evaporator section flows in parallel with inert gas and evaporates and diffuses into the latter. As explained above, inert gas rich in refrigerant flows from the lefthand end of the higher temperature evaporator section 220b to the absorber through conduit 237.

When the refrigeration apparatus is inclined from its normal operating position and both of the low and higher evaporator sections 220a and 220b slope downward from left to right in FIG. 6, liquid refrigerant will flow downward through the right-hand part of the low temperature evaporator section 220a and evaporate and diffuse into inert gas flowing in parallel therewith. The inert gas becomes partially enriched in refrigerant and flows from the right-hand end of the low temperature evaporator section through conduit 231 into the higher temperature evaporator section 220b.

Unevaporated refrigerant passes from the low temperature evaporator section 2200 into the upper end of the conduit 88 at 91 and is discharged from the lower end thereof into the higher temperature evaporator section 220b at 92 which may be referred to as a liquid inlet that is at a higher level than the liquid inlet 90 since the higher temperature evaporator section slopes downward from left to right. The liquid refrigerant introduced at the liquid inlet 92 into the higher temperature evaporator section 220b flows countercurrent to inert gas and evaporates and diffuses into the latter. The inert gas enriched in refrigerant flows from the left-hand end of the higher temperature evaporator section 220b to the absorber through the conduit 237.

Any unevaporated refrigerant in the higher temperature evaporator section 220b can flow therefrom to the conduit 237 through the conduit 93 which desirably is inclined to such an extent that the flow of refrigerant will not be blocked therein at any inclination of the refrigeration apparatus that can be tolerated without adversely affecting the normal operation of the refrigeration apparatus.

Each half of the low temperature evaporator section 220a desirably should be capable of producing adequate refrigeration to satisfy the load requirements to which it is subjected. However, there always is a small surplus of liquid refrigerant in each half of the low temperature evaporator section when it becomes inactive and the other half becomes active, and the evaporation and diffusion of such surplus refrigerant into inert gas contributes to meet the load requirements on the low temperature evaporator section 220a.

In the embodiment of FIG. 6 which just has been described, the best efiiciency is achieved when the branch point or fork 86 in the path of flow of refrigerant, the regions 89 and 91 and the liquid inlets 90 and 92 are positioned substantially in the same vertical plane.

On boats, particularly boats of large size, it is desirable to position a refrigerator provided with refrigeration apparatus embodying my invention with the plane of the refrigeration apparatus in the fore-aft direction of the boat. This is so for the reason that the rocking of a boat in the fore-aft direction never exceeds about and is less than the railings? the boat sideways. Under these conditions refrigeration apparatus embodying my invention will not malfunction and will continue to produce useful refrigeration when the refrigerator cabinet tilts backward from its rear side or forward from its front side through an angle from the vertical of as much as or tilts from the vertical to the left or right through an angle of as much as 5.

I claim:

1. Absorption refrigeration apparatus having a. a gas circuit comprising an evaporator including a part providing an elongated horizontally extending passageway,

b. a source of refrigerant in liquid phase,

c. conduit means for conducting refrigerant in liquid phase from said source to the opposing ends of said part for flow through said passageway, and

d. said conduit means being so constructed and arranged that refrigerant in liquid phase will flow there-through from said source to whichever end of said part that is at the higher level when the apparatus is tilted.

2. Absorption refrigeration apparatus having a. a gas circuit comprising an evaporator including a part providing an elongated passageway,

b. said part being substantially horizontal in the normal position of the apparatus,

c. a source of liquid refrigerant,

d. conduit means for conducting liquid refrigerant from said source to the opposing ends of said part for flow through said passageway, and

e. said conduit means being so constructed and arranged that, when said apparatus is inclined from its normal position, liquid refrigerant will flow therethrough from said source to whichever end of said part that is at the higher level.

3. Absorption refrigeration apparatus having a. a gas circuit comprising an evaporator including a part providing an elongated passageway,

b. said part being substantially horizontal in the normal position of the apparatus,

0. a source of liquid refrigerant,

d. said part having inlets for liquid at opposing ends thereof,

e. conduit means for conducting liquid refrigerant from. said source to said liquid inlets for flow through said passageway, and

f. said conduit means being'so constructed and arranged that, when said apparatus is inclined from its normal position, liquid refrigerant will flow therethrough from said source to whichever liquid inlet that is at the higher level.

4. Absorption refrigeration apparatus as set forth in claim 3 in which a. said conduit means includes supply lines for respectively conducting liquid refrigerant to the liquid inlets of said part,

b. each of said supply lines having a region which 1. moves upward when the apparatus is inclined from its normal position in such a direction that the liquid inlet associated therewith moves downward and 2. moves downward when the apparatus is inclined from its normal position in such a direction that the liquid inlet associated therewith moves upward.

5. Absorption refrigeration apparatus as set forth in claim 4 in which a vertical plane extending through said regions in said supply lines is substantially parallel to a vertical plane passing through the longitudinal axis of said evaporator part.

6. Absorption refrigeration apparatus as set forth in claim 4 in which the extent of upward movement of said region in one of said supply lines is substantially the same as the extent of downward movement of said region in the other of said supply lines.

7. Absorption refrigeration apparatus as set forth in claim 4 in which said source of liquid refrigerant comprises a condenser which includes the portions of said conduit means extending in the direction of liquid flow, said portions terminating at said regions of said supply lines.

8. Absorption refrigeration apparatus as set forth in claim 4 in which a. said conduit means for conducting liquid from said source includes a main conduit terminating at a fork in the path of liquid flow and said supply lines comprise branch conduits extending from said fork to the liquid inlets of said evaporator part,

b. each of said branch conduits having a bend and a pair of arms extending therefrom,

c. the bends in said branch conduits constituting said regions in said-supply lines, and

d. one arm of each branch conduit extending from said fork to said region of said branch conduit and the other arm, which is longer, extending from said region to the liquid inlet of said evaporator part associated with said branch conduit.

9. Absorption refrigeration apparatus as set forth in claim 7 in which a. gas in said circuit circulates through said evaporator from an inlet to an outlet thereof, said evaporator part having one end thereof at the inlet and the opposing end removed therefrom,

b. one of said branch conduits being connected to the liquid inlet at the end of said evaporator part at the inlet of said evaporator, and

c. the other branch conduit, when the apparatus is in its normal position and upright, being so constructed and arranged that a zone thereof will be at a higher level than any zone of said one branc conduit.

10. Absorption refrigeration apparatus as set forth in claim 7 in which a. gas in said circuit circulates through said evaporator from an inlet to an outlet thereof, said evaporator part having one end thereof at the inlet and the opposing end removed therefrom,

b. one of said branch conduits being connected to the liquid inlet at the end of said evaporator part at the inlet of said evaporator, and

c. a connection conducting liquid refrigerant from said evaporator part, at a region thereof adjacent to the liquid inlet associated with one branch conduit, to another region of said evaporator which is at a level below the liquid inlet associated with the other branch conduit,

d. said connection having a trap for collecting liquid refrigerant to form a liquid seal.

l 1. Absorption refrigeration apparatus as set forth in claim 9 which includes means in said evaporator part providing a darn between the liquid inlet to which said one branch conduit is connected and the region said connection is connected to said evaporator part.

12. Absorption refrigeration apparatus as set forth in claim 3 in which a. said source of liquid refrigerant comprises a condenser and b. said conduit means for conducting liquid from said condenser includes a main conduit terminating at a fork in the path of liquid flow and said supply lines comprise branch conduits extending from said fork to the liquid inlets of said evaporator part, and c. said conduit means being so constructed and arranged that portions of said branch conduits function as the tail end of said condenser.

13. Absorption refrigeration apparatus as set forth in claim 3 in which a. said source of liquid refrigerant comprises a condenser and b. said conduit means for conducting liquid from said condenser includes a main conduit terminating at a fork in the path of liquid flow and said supply lines comprise branch conduits extending from said fork to the liquid inlets of said evaporator part, and c. said conduit means being so constructed and arranged that portions of said branch conduits function as sections of said evaporator.

14. Absorption refrigeration apparatus as set forth in claim 3 in which a. said evaporator comprises low and higher temperature sections, respectively, each of said evaporator sections being substantially straight and providing an elongated passageway,

b. said higher temperature evaporator section being disposed below said low temperature evaporator section,

0. both of said low and higher temperature evaporator sections being substantially horizontal in the normal position of said apparatus,

d. a first conduit for conducting liquid refrigerant from said source to said low temperature evaporator section at a region intermediate its ends,

e. second conduits for conducting liquid refrigerant from the ends of said low temperature evaporator section to the ends of said higher temperature evaporator section, each of said second conduits being connected to one end of said low temperature evaporator section and an oppositely located end of said higher temperature evaporator section,

f. said higher temperature evaporator section constituting said part of said evaporator having inlets for liquid at opposing ends thereof and to which said second conduits are connected, and

g. said conduit means for conducting liquid refrigerant from said source to said liquid inlets of said higher temperature evaporator section comprising said first and second conduits and said low temperature evaporator section.

15. Absorption refrigeration apparatus as set forth in claim 13 in which said second conduits are formed with traps in which liquid refrigerant can collect to provide liquid seals therein.

UNITED STATES PATENT OFFICE CERTIFICATE OF CURRECTION Patent 3,760,602 Dated September 25, 1973 Inv n r( Pete'r- Erik Blomberg It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover page, item 30] "833l L/7l" after Sweden" should read 873'4/71 Column 6, line 35, uprignt" should read upright Column 9, line 57, after "The" insert part Column 1.1 claim 9, line 2, the numeral "7" should I read 8 and I I claim 10, line 2, the numeral "7" should read 8 Column 15, claim ll, line 2, the numeral 1'9" should read l0 Column l6, claim 15, line 2, the nwneral "13" should read 1L4.

Signed and sealed this 26th day of February l97) (SEAL) Attest: V EDWARD M.FLET0HER,JR. MARSHALL ,DANN

Attesting Officer Commissioner of Patents useoMM-oc scan-Pee U.5. GOVERNMENT PRINTING OFFICE 2 l9! 0-356-334,

Patent Citations
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US2312144 *Feb 3, 1940Feb 23, 1943Servel IncRefrigeration
US2395392 *Jun 1, 1942Feb 26, 1946Hoover CoRefrigeration
US2407733 *May 15, 1941Sep 17, 1946Servel IncTwo temperature evaporator for inert gas type absorption refrigerators
US2566171 *Dec 23, 1947Aug 28, 1951Hoover CoAbsorption refrigeration
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4176529 *Sep 5, 1978Dec 4, 1979Kuhlapparate Gmbh SibirAbsorption refrigerating unit
US4178774 *Sep 1, 1978Dec 18, 1979Consul S. A.Absorption refrigeration apparatus
US7047760 *Nov 15, 2004May 23, 2006Holman Jr Norman WCombination AC/HP-refrigerator apparatus and method
Classifications
U.S. Classification62/490, 62/493
International ClassificationF25B39/02, F25B15/10
Cooperative ClassificationF25B39/026, F25B15/10, Y02B30/62
European ClassificationF25B39/02C, F25B15/10