US2986906A - Absorption refrigerating machine - Google Patents

Description

June 6, 1961 E. M. STUBBLEFIELD ETAL 2,986,996

ABSORPTION REFRIGERATING MACHINE S SheetS-Sheet 1 Filed June 23, 1958 w SE n Rm w 0 E O\ n! T M vm ulnar. MSW R E vw... m W W T ME v4 D R M w HHHHHII H w June 6, 1961 E. M. STUBBLEFIELD ETAL 2,986,906

ABSORPTION REFRIGERATING MACHINE 3 Sheets-Sheet 2 Filed June 23, 1958 w E m n T E E m N E 8 R V R O mmu v" M A o g WP m.

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June 6, 1961 E. M. STUBBLEFIELD ErAL 2,986,906

ABSORPTION REFRIGERATING MACHINE Filed June 25, 1958 3 Sheets-Sheet 3 p 2,986,906 ABSORPTION REFRIGERATING MACHINE Edward M. Stubblefield and ler Edberg, La Crosse, Wis., assignors to The Trane Company, La Crosse, Wis., a corporation of Wisconsin Filed June 23, 1958, Ser. No. 743,798 7 Claims. (Cl. 62-487) This invention relates to refrigerating and more particularly to a self-contained or unitary refrigerating apparatus of improved construction.

The principal object of the present invention is to provide a unitary refrigerating apparatus in which the generator, condenser, absorber and evaporator are enclosed in a single shell with passageways internal of the shell for the flow of refrigerant from the generator to the condenser and from the evaporator to the absorber.

It is another object of the invention to provide a structure in which walls of the generator and condenser serve to separate the high pressure section from the low pressure section of the shell.

It is another object of the invention to provide a compact and economical absorption refrigerating apparatus embodying an eflicient arrangement of the elements of the system which assures efiicient operation and which reduces the space required for the apparatus in use.

Still another object of the invention is to provide an absorption refrigerating machine of the type indicated which is of simpler construction requiring fewer parts and less material, and one which is more economical to manufacture requiring fewer welds and less leak testing than previously known refrigerating uni-ts of! the same capacity.

These and other objects will become more apparent from the following description and drawings in which like reference characters denote like parts in the several views. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and not a definition of the limits of the invention, reference being had for this purpose to the appended claims. In the drawings:

FIG. 1 is front elevational view partly diagrammatic of the absorption machine of this invention;

FIG. 2 is an end elevational view as seen from the left of FIG. 1;

FIG. 3 is an end elevational view as seen from the right of FIG. 1;

FIG. 4 is a sectional view taken on line 4-4 of FIG. 1; and

FIG. 5 is a partial side view with portions of the casing and interior structure broken away to more clearly show the interior construction.

Referring now to the drawings, there are provided feet secured to and supporting a horizontally extending drum or shell 12. Shell 12 encloses a longitudinally extending absorber 14 in its lower portion. We prefer that the absorber shall be substantially centered with respect to the vertical longitudinal diametral plane of the shell 12. A longitudinally extending evaporator 16 is mounted in the shell 12 above the absorber 14. We prefer to mount the evaporator 16 offset from the vertical longitudinal diametral plane of the shell 12. Also mounted in the shell 12 above the absorber 14 and to one side of the evaporator 16 is a generator 18. A longitudinally extending condenser 20 is located in the shell at the top. The condenser 20 is approximately centered with respect to the vertical longitudinal diametral plane of the shell 12 and it is therefore horizontally offset from the generator.

The absorber 14 has a plurality of tube supports 22 States Patent C) which support tubes 24. Tubes 24 communicate with an inlet header 26 and an outlet header 28. Cooling water flows through the absorber 14 via inlet header 26, tubes 24, and outlet header 28.

Spray trees 30 distribute the solution over the tubes 24 whereby heat is transferred from the solution to the cooling water flowing in the tubes 24. The solution then flows out of the shell through pipe 32. A strainer 33 prevents foreign particles from entering pipe 32.

Various combinations of refrigerant and absorbent may be used in the present machine. A solution of lithium bromide and water has been found to be highly satisfactory for use. Other salt solutions may be used if desired. For instance, the solution may be lithium chloride and water or sodium hydroxide and water. When it is necessary to produce low temperatures, other absorbent and refrigerant combinations may be used. When lithium chloride and water are used, the system will be under a vacuum with the generator and condenser at a higher absolute pressure than the evaporator and absorber.

A solution recirculating pump 34 has its inlet connected to the pipe 32 and pump 34 discharges into pipe 36 which is connected to the spray trees =30. The solution sprays greatly increase the surface area of the solution thus increasing the absorption capacity. The movement of the solution over the tubes increases the heat transfer.

The evaporator 16 has horizontally extending walls which form with the end walls 38' and 40 of the shell an evaporator compartment 42.

Tube supports 44 are secured to the walls of the evaporator compartment 42 and support the evaporator tubes 46. Chilled water from a refrigeration load such as air conditioning devices enters the evaporator tubes 46 through header 48 and leaves through header 50.

Refrigerant is sprayed over the tubes 46 from a spray tree 52. The unevaporated refrigerant leaves the shell through a pipe 54 leading to a refrigerant reservoir 56. A refrigerant pump 58 is connected to draw refrigerant from the reservoir 56 and to discharge the refrigerant into a pipe 60 which is in fluid communication with the spray tree 52. The movement of the sprayed refrigerant over the tubes improves the heat transfer.

The solution in the absorber 14 absorbs water vapor from the refrigerant in the evaporator 16 thus establishing a reduced pressure in the evaporator. At the reduced pressure, the refrigerant boils. The chilled water flowing in the tubes 46 transfers its heat to the refrigerant and is itself reduced in temperature so that it may be circulated again to the refrigeration load. The water vapor flows from the evaporator to the absorber through a passageway 62 between the evaporator 16 and the generator 18.

It is apparent that the solution in the absorber 14 is diluted by the vapor from the evaporator and that there must be some means for concentrating the solution if the process is to be sustained. A pump 64 receives dilute solution from the absorber 14 through a pipe 66 and discharges the dilute solution into a counterflow heat exchanger 68. A strainer 67 prevents foreign particles from entering pipe 66. In the heat exchanger 68, the dilute solution passes through pipe 70 to the generator 18.

The generator 18 has a longitudinally extending wall 71 secured at one side to the shell 12 and at the other side to condenser casing 72. The generator 18 has tube sup ports 74 supporting a plurality of tubes 76 which are in fluid communication with an inlet steam header 80 and an outlet steam header 82. The steam in the tubes 76 heats the solution in the generator 18 causing it to boil and send refrigerant vapor through a first set of elimi- 3 nators 84 and thence througha second set of eliminators 86 .into the condenser 20. H V g As vapor is removed from the solution by boiling in the generator 18, the solution in the generator is increased in concentration. The concentrated solution flows from the generator .l8through an opening 102 into a chamber 104. A baffie 106 in chamber 104 causes the solution to flow smoothly into a pipe 108 without trapping vapor or inert gas. The pipe 108 conducts the hot concentrated solution to the heat exchanger 68 from which it flows into the absorber 14 through a pipe 110.. The pipe 110 enters the absorber at a point close to the pipe 32 leading to the solution recirculating pump 34. Therefore, the solution recirculated by the pump 84 is moreconcentrated than the solution at the other end of the shell 12. It also follows that the solution withdrawn through pipe 66 for return to the generator 18 is more dilute than the solution at the other end of the shell 12. There is a pressure equalizer opening 109 and a drain opening 111 between the chamber 104 and the generator .18. The drain opening 111 provides means for removing solution from the generator when it is desired to remove all the solution from the machine. The opening 111 is so small that it has a negligible etfect during operation.

When the machine is started up after a shut down, there is a tendency for solution to accumulate in the generator until the difference in pressure has been established between the generator and absorber and until the generator and condenser are operating to remove refrigerant from the solution in the generator 18. As the level rises in the generator 18 above the normal level 112, the solution flows through pipe 113 to the absorber 14. The pipe 113 has a trap 114 which maintains the pressure difierence between the generator 18 and the absorber 14.

The condenser 20 has, at spaced intervals along its length, a plurality of transversely extending tube supports 88 which support tubes 90. A two pass condenser is shown. However, the condenser 20' may have one or three or more passes. The tubes 90 are in fluid communication with headers 92 and 94. A pipe 96 conducts cooling water from header 28 of the absorber to inlet 98 in header 94. The cooling water is discharged from the condenser 20 through outlet 100. Header 92 merely provides fluid communication between the tubes of one pass and the tubes of the other pass.

Refrigerant from the condenser 20 flows through a pipe 116 to the evaporator 16. An orifice 118 in the pipe 116 controls the flow through pipe 116 to maintain a pressure difierence between the condenser 20 and the evaporator 16 and to prevent any substantial amount of vapor from blowing from the condenser 20 to the evapo rator 16.

It should be understood that this refrigerating machine will have the usual controls (not shown) to start and stop the machine and control its capacity.

While a single embodiment of the present invention has been illustrated and described, it should be understood that modifications may be made in the construction and arrangement of elements and therefore we desire to be limited only by the claims. I

We claim:

1. An absorption refrigerating machine comprising a unitary sealed horizontal substantially cylindrical elongated container having therein an absorbent and a refrigerant, an elongated partition extending longitudinally of said container and having each of its longitudinal sides secured to the cylindrical wall of said container to divide said container into a high pressure upper chamber and a low pressure lower chamber, a generator and a condenser in the high pressure upper chamber of said container, an absorber and an evaporator in the low pressure lower chamber of said container, said evaporator being constructed and arranged with respect to said elongated partition to provide a downwardly extending passageway between the evaporator and said elongated partition for the flow of refrigerant vapor from said evaporato said container for conductingabsorbent frofiisaid generator to said absorber, conduit means extending exterior to said container for conducting absorbent from said absorber to said generator, means for conducting refrigerant from said condenser to said evaporator and means in said high pressure upper chamber for conducting refrigerant from said generator to said condenser.

2. An absorption refrigerating machine comprising a unitary sealed horizontal substantially cylindrical elongated container having therein an absorbent and a nefrigerant, an elongated partition extending longitudinally of said container and having each of its longitudinal sides secured to the cylindrical wall of said container to form with the substantially cylindrical wall of said container a high pressure upper chamber and a low pressure lower chamber, a generator and a condenser in the high pressure upper chamber of said container, an absorber and an evaporator in the low pressure lower chamber of said container, said absorber being in the lowermost portion of the container, said evaporator being arranged above said absorber and being spaced horizontally from said partition to provide a downwardly extending passageway between said evaporator and said partition for the flow of refrigerant vapor from said evaporator to said absorber.

3. An absorption refrigerating machine comprising a unitary sealed horizontal substantially cylindrical elongated container having therein an absorbent and a refrigerant, an elongated partition extending longitudinally of said container and having each of its longitudinal sides secured to the cylindrical wall of said container to form with the wall of said container a high pressure chamber anda low pressure chamber, both of the chambers extending substantially the length of said container, a generator and a condenser in the high pressure chamber of said container, an absorber and an evaporator in the low pressure chamber of said container, said absorber being in the lowermost portion of said container, said evaporator being above said absorber and being offset from the vertical diametrical plane of said container, said generator being above said absorber and being offset from the vertical diametrical plane of said container in a direction opposite to the offset of said evaporator, means in said high pressure chamber for conducting refrigerant vapor from said generator to said condenser, and means in. said low pressure chamber for conducting refrigerant vapor from said evaporator to said absorber.

4. An absorption refrigerating machine comprising a unitary sealed horizontal substantially cylindrical elongated container, means dividing said container longitudinally into a high pressure chamber and alow pressure chamber with the high pressure chamber above said low pressure chamber, a generator and a condenser in said high pressurechamber, an absorber and an evaporator in said low pressure chamber, means for conducting refri'gerant vapor from said generator to said condenser, means for conducting refrigerant vapor from said evaporator to said absorber, a first conduit for conducting absorbent solution from said generator to said absorber, and an overflow conduit separate from said first conduit throughout its length and having one end in fluid communication with said generator at a point above the normal operating level of solution in said generator and having its other end in fluid communication with said absorber to provide a second passageway for flow of absorbent solution from the generator to the absorber when the level of absorbent solution in the generator rises above the normal operating level.

5. An absorption refrigerating machine comprising an absorber, an evaporator, a generator, and a condenser in a sealed system containing an absorbent and a refrigerant, means for conducting refrigerant from said generator to said condenser, means for conducting refrigerant from said condenser to said evaporator, means for conducting refrigerant from said evaporator to said absorber, a first conduit for conducting absorbent from said absorber to said generator, a pump in said first conduit, a second conduit in fluid communication with the generator below the normal operating level of absorbent in said generator for conducting absorbent from said generator to said absorber, means for transferring heat between said first and second conduits, and a third conduit having one end in fluid communication with said generator at a point above the normal operating level of solution in the generator, said third conduit bypassing said heat exchanger and being in fluid communication with said absorber to conduct fluid from said generator to said absorber when the level of absorbent in the generator rises above the normal operating level.

6. An absorption refrigerating machine comprising an absorber, an evaporator, a generator, and a condenser in a sealed system containing an absorbent and a refrigerant, means for conducting refrigerant from said generator to said condenser, means for conducting refrigerant from said evaporator to said absorber, a first conduit for conducting absorbent from said absorber to said generator, a pump in said first conduit, a second conduit in fluid communication with the generator below the normal operating level of absorbent in said generator for conducting absorbent from said generator to said absorber, a heat exchanger interposed in said first and second conduits to transfer heat therebetween, and a third conduit in fluid communication with said generator and said absorber, said third conduit bypassing said heat exchanger, a liquid trap in said third conduit to prevent flow of vapor from said generator to said absorber, said third conduit being constructed and arranged to conduct absorbent irom said generator to said absorber only when the level 6 of absorbent in the generator substantially exceeds the normal operating level.

7. An absorption refrigerating machine comprising a unitary sealed horizontal substantially cylindrical elongated container having therein an absorbent and a refrigerant, an elongated partition extending longitudinally of said container and having each of its longitudinal sides secured to the cylindrical wall of said container to divide said container into a high pressure upper chamber and a low pressure lower chamber, a generator and a condenser in the high pressure upper chamber of said container, said generator and'said condenser being constructed and arranged in said high pressure upper chamber so that no substantial portion of said condenser is in vertical alignment with said generator, an absorber and an evaporator in the low pressure lower chamber of said container, said evaporator being constructed and arranged above said absorber, first conduit means extending exterior to said container for conducting absorbent from said generator to said absorber, second conduit means extending exterior to said container for conducting absorbent from said absorber to said generator, means for conducting refrigerant from said generator to said condenser, and means for conlucting refrigerant from said evaporator to said absor er.

References Cited in the file of this patent UNITED STATES PATENTS 2,196,911 Getaz Apr. 9, 1940 2,365,797 Bichowsky Dec. 26, 1944 2,378,177 Bichowsky June 12, 1945 2,678,547 Ashley May 18, 1954 2,755,635 Bourne July 24, 1956 2,770,953 Leonard Nov, 20, 1956

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