US2312144A - Refrigeration - Google Patents

Description

Feb. 23, 1943- G; M. BLOMQVIST REFRIGERATION Filed Feb. 5, 1940 INVENTOR.

Patented Feb. 23, 1943 REFRIGER TION Gustav Marten Blomqvist, Stockholm, Sweden, assignor, by mesne assignments, to Servel, Inc., New York, N. Y., a corporation of Delaware Application February 3, 1940, Serial No. 317,056

18 Claims.

My invention relates to refrigeration, and more particularly to refrigeration systems of an absorption type in which refrigerant fluid is expelled out of solution by heating.

In refrigerators of the household type it is desirable to provide separate cooling elements for space cooling and for the production of ice cubes and other frozen matter. The cooling elements are preferably connected in such a manner in a refrigeration system that the cooling element primarily effecting space cooling operates at a higher temperature than the cooling element primarily employed for freezing ice cubes and the like. In many instances it is desirable to increase the refrigerating effect produced by the space cooling element without increasing the refrigerating effect produced by the lower temperature cooling element. This is true when there is no need for ice cubes. There are also times when it is desirable to hasten the production of ice cubes and the like without increasing the refri erating effect produced by the space cooling element.

It is an object of the invention to provide the improvement in refrigeration systems of the absorption type whereby a plurality of cooling ele-. ments employed for space cooling and for the production of ice cubes may be controlled so that the refrigerating efiect produced by one cooling element may be increased without increasing the refrigerating efiect produced by another cooling element.

The above and other objects and advantages of the invention will be better understood from the following description taken in conjunction with the accompanying drawing forming a part of this specification, and. of which the single figure more or less diagrammatically illustrates a refrigeration system embodying the invention.

Referring to the drawing, a first generator ill includes an inner hollow member Ii surrounded by an outer shell i2. A second generator i3 is connected to the lower part of shell H. A bafile i4-is provided-within shell [2 just above the connection thereto of generator i3. This bafile extends approximately half way across the shell. A similar baiile i5 is disposed within-the shell l2 below and on the opposite side from bafile l4.

Located within the hollow member I I are four electric heating elements a, b, c and d. Element agis located within a portion of the member II which extends below and beyond the lower end of the shell i2. Element 1) is located within the portion of member ll above the lower end of the shell and below the baflle l5. Element 0 is located between the baflles l4 and 15, while element dis disposed above the baffle 14. On terminal of each of the heating elements is connected to one side It of an electric circuit ii in which are provided a thermostatic switch 38 and a manual switch I9. The other terminal of ele-- ment at is connected directly to the other side 20 of the circuit ll, so that current is supplied to this element when switches i8 and ii! are closed.

The other terminals of heating elements b, c, and d, are connected to contacts 2!, 22 and 23, respectively, of a multiple switch. Adjacent to each of these contacts are contacts 24, 25 and 25, respectively, each of which is connected to the side 20 of the circuit ii. The multiple switch includes a rotatable contact arm 27 which, in the position shown, bridges contacts 2| and 24, there- 'by closing the circuit of heating element b. Arm

it may be rotated from the position shown so that it will bridge either contacts 22 and 25 or contacts 23 and 25, thereby closing the circuits of elements c or d, respectively. v

Connected to the upper part of generator in is a conduit 30 provided with heat transfer fins 3i. Conduit 30 is connected to the upper end of a iirst condenser 32, the lower end of which is connected by a conduit 33 with an evaporator 34 provided with'heat transfer fins 35 and arranged for cooling the space within cabinet 36.

A conduit 31, which extends upward from the upper end of generator i3 and is provided with heat transfer fins 38 at its lower portion, is connected to the upper end of a condenser 39. The lower end of condenser 39 is connected by a conduit 40 to an evaporator 4i including a pipe coil arranged to absorb heat from ice trays 42 supported within a substantially closed shell 43.

A conduit 44 connects the upper end of evaporator M, to a chamber 45 formed inthe end of a gas heat exchanger 46. A plurality of tubes 41 connect chamber 45 with a similar chamber 48 at the other end of the heat exchanger. The tubes 51 are supported by headers 49 and 50 which separate the chambers 45 and 43 from a central space iii. The lower end of evaporator ii is connected at 52 to space 5 I.

A conduit 53 extends upward from space 5| and communicates with the upper part of evaporator 34 at the same end to which conduit 33 is connected. A conduit 54 is connected to the opposite end of evaporator 34 and to the space 5 I.

A vertical baiile 55 extends across the bottom of evaporator 34 near this end and a conduit 56 extends downward from the upper evaporator at the right of the baflle 66 and is connected at its lower end to conduit 49.

Conduits 23 and 49 both extend upwardly beyond their connections to condensers 32 and 29,

respectively, and at their upper ends are connected to one end of a pressure vessel 61. A conduit 58 connects the other end of pressure vessel 51 and the space 6|.

A conduit 60 connects space 46 of the gas heat exchanger to the upper end of an absorber 6|. The lower end of the absorber is connected to the space 5| by a conduit 62. The lower end of conduit 62 is also connected to a vessel 63 from the bottom of which extends a conduit 64 connected to the outer jacket 66 of-a liquid heat exchanger 66.

A conduit 61 connects the other end of the jacket to a pipe coil 69 which forms a thermosyphon pump and is wound around that portion of hollow member projecting below shell l2 and within which is located the heating element a. A conduit 69 connects the upper end of coil 68 to the upper part of generator l3. One end of a conduit 19 is connected to an upper part of generator I 6 and extends within jacket 65 and the other end thereof is connected to the upper end of absorber 6|.

A thermostatic element II is located within the refrigerator cabinet 36 and is connected by a tube 12 to a diaphragm chamber 13. The diaphragm within chamber 13 is so connected to the switch l8 as to open the switch when the temperature of the thermostatic element 1| has fallen to a predetermined value, and to close the switch when the temperature-of the element rises above this value. Opening of this switch opens the circuits of all the heating elements.

The above described apparatus operates as follows:

Assuming that the switch I9 is closed and that the temperature of the thermostatic element II is sufficiently high so that the switch i6 is also closed, current will be supplied to the heating element a. The heat generated by this element serves to heat the liquid within the coil ,68 sufliciently to vaporize a portion of this liquid. The vapor bubbles thus formed serve to raise the remaining liquid through the conduit 69 to the upper part of generator I3. With the contact arm 21 in the position shown, the circuit of heating element b is closed. The heat produced by this element serves to heat the solution of refrigerant, such as ammonia, dissolved in absorption liquid, such as water, in the lower part of the jacket l2 below the baiiie l5 and hence causes refrigerant to be driven from the solution in the form of vapor bubbles. Baiiles l5 and I4 cause these bubbles of refrigerant vapor to pass into the lower end of the generator Hi. The bubbles travel upwardly through the liquid in this generator and the vapor passes through the conduit 31 to the condenser 39. The vapor is cooled somewhat by the fins 38, which causes the condensation of any water which may have been vaporized. In the condenser 39 the vapor is further cooled and the refrigerant is thereby liquefled. This liquid flows from the lower end of the condenser 39 through the conduit 46 to the upper end of the evaporator 4|.

In the evaporator the liquid refrigerant flows into the presence of an inert gas, such as hydrogen, which enters through the conduit 44. Refrigerant in evaporator 4| evaporates and diffuses into the inert gas to produce a refrigfrom the surroundings. The rich gas mixture of refrigerant and hydrogen passes downwardly through the evaporator 4| and into the space SI of the gas heat exchanger. The rich gas flows through this space around the tubes 4! and through the conduit 62 to the lower end of the absorber 6|.

Weak absorption liquid is supplied to the upper end of the absorber by the conduit 10 and flows downwardly countercurrent to the gaseous mixture. The refrigerant is absorbed by the weak solution, while the inert hydrogen is not absorbed and flows from the upper end of the absorber through the conduit 60 to the space 48 in the gas heat exchanger. From here it flows through the tubes 41, space 45 and conduit 44 back to the upper end of the evaporator 4|.

The strong absorption solution formed in the absorber flows from the lower end thereof through vessel 63, conduit 64, jacket and conduit 61 to the coil 68. As previously described, the heating of the solution in this coil by means of the heating element a lifts it to the upper end of the generator IS. The solution flows downwardly through the generator into the lower part of jacket l2 and thence upwardly through the jacket and through the conduit 10 back to the upper end of the absorber 6|.

Under the conditions above described refrigerant is supplied chiefly to the ice freezing evaporator 4| and little or no refrigerant is supplied to the cabinet cooling evaporator 34. Hence, substantially the entire capacity of the apparatus is concentrated on freezing ice with the result that ice may be frozen very rapidly.

If, on the other hand, it is desired to rapidly chill the interior of the cabinet 36, the contact arm 21 is rotated so as to bridge the contacts 23 and 26, whereby current is supplied to the heating element d. Inasmuch as this element is located above the lower end of the generator l3 and above the baffle H the refrigerant vapor produced by the heating effect of the element d passes upwardly through the jacket l2 and through the conduit 30 to the condenser 32. The vapor is here liquefied and the liquid flows from the lower end of the condenser through the conduit 33 to the cabinet cooling evaporator 34. Inert gas is introduced into this evaporator through the conduit 53, with the result that the refrigerant evaporates within the evaporator 34 and absorbs heat from the interior of the cabinet. If more liquid refrigerant is supplied to the evaporator than is evaporated therein, it overflows the bailie 55 and is conducted through the conduit 56 to the conduit 40. The gaseous mixture of refrigerant and hydrogen formed in the evaporator 34 flows therefrom through the conduit 54 to the space 5| and thence through conduit 62 to the absorber 6|, as previously described.

Under these conditions practically no refrigerant is supplied from the generator l3 to the erating effect, with consequent absorption of heat evaporator 4| and consequently the entire capacity of the apparatus is made available for reducing the temperature within the cabinet.

Since the inert gas flows first through evaporator 4| and then flows through evaporator 34 after leaving evaporator 4|, the gas in evaporator 34 contains a greater amount of ammonia vapor than the gas in evaporator 4|. The partial pressure of ammonia vapor is therefore higher in evaporator 34 than in evaporator 4|, and evaporation of liquid ammonia takes place at a higher temperature in evaporator 34 than in evaporator asiarcs. a

The evaporator M is provided'with a limited heat transfer surface and is primarily employed for the production of ice cubes and the'like. The evaporator 34 is provided with the heat transi'er this 35 to provide a relatively extensive heat transfer surface and is primarily employed for space cooling.

Under normal operating conditions, when it is desired to chill both the cabinets and freeze ice,

the contact arm is rotated so as to bridge the oontacts 22 and 25, thereby supplying current to supply liquid refrigerant to both the evaporators 3d and 4!. Hence, both of these evaporators absorb heat. Under these conditions the vapor flowing through conduit 58 to-the evaporator as is a mixture of hydrogen and refrigerant, which is produced in evaporator I; I ,but, due to the fact that evaporator it receives only about half as much refrigerant as it does when elementb is energized, this mixture is not saturated with rethe respective generators and evaporatcrs together, a condenser disposed in each conduit means, heating means for said vapor-liquid lift,

and heating means for independently heating each of said generators. 4. In an absorption refrigerating apparatus, a pair of generators connected together for flow or liquid therethrough, means including a vapor-liquid lift for raising absorption solution rich in refrigerant to one of the generators, means for withdrawing absorption solution weak in refrigerant from the other generator, a pair of evaporators, separate conduit means connecting the respective generators and evaporators together, a condenser disposed in each conduit means, a heater for said vapor-liquid lift,'a common heater for both of said generators, and additional heaters each of which is primarily adapted for use with one of said generators. 5. Generator means for an absorption refrigerating apparatus including a vertically extending frigerant vapor and its introduction into the presence of the liquid refrigerant in evaporator 34 serves to reduce the partial pressure of the refrigerant therein sumciently to cause it to evaporate. I

Thus it will be seen that I have provided an apparatus wherein the supply of refrigerant to the two evaporators may be controlled independently in such a manner that all of the'refrigerant may be supplied to either evaporator, or it may be divided between the two.

While I have shown and described one more or less specific embodiment of my invention, it

is to be understood that this has been done for the purpose of illustration only and is not to be considered as limiting the scope of my invention, which is to be determined by the iollowing'claims.

What is claimed:

1. In an absorption refrigerating apparatus, a pair of generators connected together for series flow of liquid therethrough, means for supplying absorption solution rich in refrigerant to the first generator, means for withdrawing absorption solution weak in refrigerant from the second generator, at low temperature evaporator, a higher temperature evaporator, conduit means for connecting said first generator to said low temperature evaporator, conduit means for connecting said second generator with said higher temperature evaporator, a condenser disposed in each of said conduit means, and means for controlling refrigerant vapor expulsion in said generators.

2. In an absorption refrigerating apparatus, a pair of generators connected together for flow of liquid therethrough, a pair of evaporators, separate conduit means connecting the respective generators and evaporators together, a condenser disposed in each conduit means, heating means for independently heating each of said generators, and a common heating means for heating both of said generators.

3. In an absorption refrigerating apparatus, a pair of generators connected together for flow hollow member, a shell around said hollow mem-' ber forming therewith an annular space, a tubular member connected to said space adjacent to one end thereof, a first baflle means extending from the side of said shell part way across said space immediately above the point of communication therewith of said tubular member, a second baiiie means extending from the opposite side of said shell part way across said space below said point of communication, a first heating means within said hollow member above the upper baffie-means, a second heating means within said hollow member between said baflle means, and a third heating means within said hollow member below the lowerbafile i'neans.

6. Generator means for an absorption refrigerating apparatus including a vertically extending hollow member, a shell. around said hollow member forming therewith an annular space, a tubular member connected to said space adjacent to one end thereof, a first bame means extending from the side of said shell part way across saidspace immediately abovethe point ofcommunication therewith of said tubular member, a second bailie means extending ironi' the opposite side of said shell part way across said space below said point of communication, a first heating means within said hollow member means within said hollow member between said baflle means, a third heating means within said oi liquid therethrough, means including a vapor liquid lift for conducting absorption solution rich in. refrigerant hollow member below the lower baffle means, said hollow member having a portion extending below said shell, a thermo-syphon pump in heat exchange relation with said portion, and a fourth heating means within said portion.

7. Generator means for absorption refrigerating apparatus including a vertically extending hollow member, a shell around said hollow member forming therewith an annular space, a tubu lar member connected to said space adjacent to one end thereof, a first baille means extending from the side of said shell part way across said space immediately above the point of communication therewith of said tubular member, a second bame means extending from the opposite side of said shell part way across said space below said point of communication, a first electric heating element, within said hollow member above the upper bafiie means, a second electric to one of the generators, means heating element within said hollow member between said baffle means, a third electric heating element within said hollow member below the lower baflle means, and an electric circuit, including a multiple-position switch, for selectively supplying current to any one of said elements.

8. Generator means for absorption refrigerating apparatus including a vertically extending hollow member, a 'shell around said hollow member forming therewith an annular space, a tubular member connected to said space adjacent to one end thereof, a first baffle means extending from the side of said shell part way across said space immediately above the point of communication therewith of said tubular member, a second baiile means extending from the opposite side of said shell part way across said space below said point of communication, a first electric heating element within said hollow memberabove the upper baille means, a second electric heating element within said hollow member between said baille means, a third electric heating of refrigerant vapor expulsion arranged and connected to each other so that absorption solution from which refrigerant vapor has been expelled in one region flows to another region for additional expulsion of refrigerant vapor. evaporator structure providing a plurality of vplaces inv each of which cooling is effected, conduit means for connecting in parallel said regions of vapor expulsion and said places of cooling, means in said conduit means to effect liquefaction of refrigerant vapors, and heating means for said generator so constructed and arranged that the heating effect may be utilized primarily to effect expulsion of refrigerant vapor in one of a plurality of said regions or in a plurality of said regions.

10. In absorption refrigeration apparatus having a cooling element, an absorber, a generator. and connections including a vapor-liquid lift connecting the absorber and generator to provide a circuit for circulation of absorption solution, said generator comprising structure providing a plurality of regions in which refrigerant vapor is expelled from absorption solution, evaporator structure providing a plurality of places in each of which cooling is effected, conduit means for connecting in parallel said regions of refrigerant vapor expulsion and said places of cooling, means in said conduit means to effect liquefaction of refrigerant vapor, heating structure primarily effective for heating said regions of vapor expulsion, additional heating means primarily effective to effect heating of said vapor-liquid lift, and control means for controlling 'includes a first control for said heating structure, and a second control for said additional heating means which affects said first control.

12. In absorption refrigerating apparatus as set forth in claim 10, in which said control means includes a first control for said heating structure, and a second control responsive to a temperature condition affected by said cooling element.

13. In absorption refrigeration apparatus, a generator comprising a first elongated vessel, a second elongated vessel having one end connected to an end of said first vessel, conduit means for supplying absorption solution to said second vessel at the end thereof opposite to that connected to said first vessel, conduit means for withdrawing absorption solution from an end of said first vessel opposite to that connected to said second vessel, a heater capable of heating said vessels to cause expulsion of refrigerant vapor from absorption solution therein, and conduit means for withdrawing expelled refrigerant vapor separately from said vessels for condensation and evaporation to produce refrigeration.

14. In absorption refrigerating apparatus having an absorber, a generator connected to said absorber to form a circuit for circulation of absorption solution and including structure providing two chambers having vertical extent and connected at their lower ends, conduit means for conducting absorption solution from the absorber to the upper part of one of said chambers, conduit means for conducting absorption solution from the upper part of said other chamber to the absorber, heating means for causing expulsion of refrigerant vapor from absorption solution in said chambers, and conduit means for separately withdrawing expelled refrigerant vapor from said chambers for condensation and evaporation to produce refrigeration.

15. In absorption refrigerating apparatus having a cooling element, an absorber, a generator, and connections including a pump connecting the absorber and generator to provide a circuit for circulation of absorption solution, conduit means for connecting said cooling element and said generator, a condenser in said conduit means, a heater primarily effective to cause expulsion of refrigerant vapor from solution in said generator, means associated with said pump capable of effecting operation thereof, a first control means responsive to a condition affected by the refrigerating apparatus for controlling said means associated with said pump, and additional control means for controlling said heater, said heater being rendered inoperative when operation of said pump is stopped by said firstmentioned control means.

16. In an absorption refrigerating apparatus, a plurality of generators connected together so that absorption liquid from which refrigerant vapor has been expelled in one generator flows to another generator for additional expulsion of refrigerant vapor, a plurality of condensers, means for conveying refrigerant vapor in parallel from the generators to the condensers, a plurality of evaporators, means for conveying liquid refrigerant in parallel from the condensers to the evaporators, and means for controlling the generation of refrigerant vapor in said generators.

17. In an absorption refrigerating apparatus, a pair of generators connected together so that absorption liquid from which refrigerant vapor has been expelled in one generator flows to the other generator for additional expulsion of refrigerant vapor, a. pair of evaporators, separate conduit means connecting the respective generators and evaporators together, a condenser disposed in each conduit means, and heating means for heating each of said generators.

18. In absorption refrigerating apparatus having a cooling element, an absorber, a generator,

and connections including a pump connecting the absorber and the generator toprovide a circuit for circulation of absorption solution, conduit means for connecting said cooling element and said generator, a condenser in said conduit trol structure for controlling operation of said i means associated with said pump and said heater, said control structure including a first movable control element for controlling said heater and a second control element movable independently of said first element for controlling said means associated with said pump, said control structure being so constructed and arranged that, when said means associated with said pump is rendered inoperative by said second control element, said heater is also rendered inoperative irrespective of the position of said first control element.

GUSTAV MARTEN BLOMQVIST.

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