US2260939A - Refrigeration - Google Patents

Description

Oct. 2 8, 194 1. w HAINSWQ\RTH 2,260,939

REFRIGERATION Filed Oct. 6, 1939 ZSh'eets-Sheet l INVENTOR.

' 2. BY Wm ATTORNEY.

Patented a. 2a, 1941 UNITED STATES PATENT OFFICE 2,260,939 REFRIGERATION William R. Hainswortli, Larclimont, N. Y., as-

signor to Serve], Inc., New York, N. Y., a corpo- ,ration of Delaware Application October 6, 1939, Serial No. 298,163

'IClalms,

' tures. The evaporator which operates atthe low temperature is utilized for freezing ice, while the higher temperature evaporator serves to main-- tain the desired temperature in the food'com partment of the refrigerator cabinet.

A further object of my invention is to locate the lower temperature evaporator within the higher temperatureevaporator in order to reduce the flow of heat from the food space of the refrigerator to the lower temperature evaporator. This results in a lower temperature being maintained in the ice freezing compartment.

Further objects and advantages of my invention will be apparent from the following descripend of conduit communicates with a condenser indicated generally by reference character 22.

This condenser is made up of an upper part 23 and a lower part 24. The lower end of the upper part 23 communicates with a vessel 25. The upper end of lower part 24 also communicates with vessel 25 and with avessel 26.

Reference character 21 designates generally an evaporator located within a refrigerator cabinet 28. The evaporator is made up of a low temperature part 23 and a'high temperature part 30. A conduit 3t leads from the bottom of vessel 25 to the upper end of the low temperature part 29, while a conduit 32 leads from the from the lower end of high temperature part 30.

tion considered in connection with the accompanying drawings which form a part of this.-

partially in cross section, showing a preferred embodiment of my invention;

Fig. 2 is a cross-sectional view showing an evaporator constructed in accordance with my invention within a refrigerator cabinet.

- Fig. 3 is a cross-sectional view on an enlarged scale of the evaporator shown in Fig. 2 and is taken on the lines 3-3 of Figs. 4 and 5;

Fig. 4 is a cross-sectional view taken on the lines 4-4 of Figs. 3 and 5; and

Fig. 5 is a cross-sectional view taken on the line 5--5 of Fig. 4. 1

Referring more particularly to Fig. 1 reference character l0 designates a generator or boiler which includes a centrally located flue II and an outer shell l2. A'tra'nsverse partition l3 divides the space within shell l2 into chambers I4 and I5. Chamber l4 constitutes a pumping chamber and is provided with a dome IS. A vapor lift conduit "extends through dome l6 from within chamberv l4 and communicates with the upper end of a stand pipe l8. The lower end of stand pipe I3 is connected to the upper part of chamber l5. Any suitable source of heat; such as the gas burner I9, is provided for heating the flue II and the contents of chambers l4 and IS.

A conduit 20 is-connected to the upper end of stand pipe l8 and is provided along the portion of its length with heat transfer fins 2|. This portion thus constitutes a rectifier. The upper within jacket, 43 of the heat exchanger.

Reference character 36 designates generally a gas heat exchanger having an inner pipe 31, and an outer jacket 38. Conduit 35 is connected to the upper end of inner pipe 31, while the lower end of this pipe is connected to the lower part of an absorber 39. A conduit 40 connects the upper end of the absorber with the lower end of jacket 38, while a conduit 4| connects the upper end of this jacket with the upper end of low temperature part 29 of the evaporator.

A conduit 42 leads from the lower part of absorber 39 to the outer jacket 43 of a liquid heat exchanger 44, while a conduit 45 connects the other end of this packet with pumping chamber M in the generator. A conduit 46 leads from chamber I5 of the generator and passes The other end of conduit 46 communicates with the upper part of the absorber 39.- It will be noted that the upper end of conduit 46 isbelow the upper end of vapor lift pipe l1, whereby liquid discharged from the upper end of pipe ll will flow by gravity'to the upper end of absorber 39.

A coil 50 is in heat exchange relation with absorber 33 and is connected by means of conduits 5! and 53 with a condenser 52. The closed circuit comprised of coil 50, conduits 5| and 53, and condenser 52 is partially filled with a fluid which, under the pressure prevailing in this circuit, boils in coil 50 at the temperature at which it is desired to maintain the absorber and condenser in condenser 52 at atmospheric temperature.

A pressure vessel 54 is connected to vessel the refrigerant ammonia. A gas inert with respect to both the refrigerant and the absorption medium, such as hydrogen, is also introduced into the system.

- The application of heat to the solution of ammonia in water, contained within generator l0, causes ammonia vapor to be driven off in both chambers M and I5. The-gas thus produced in pumping chamber l4 enters the lower end of vapor lift conduit |1 along with liquid, and the gas serves tolift such liquid through the conduit H to the upper end of stand pipe |8. The liquid flowsdownwardly through the stand pipe while ammonia gas produced in chamber |5 bubbles upwardly through the stand pipe. The diameter of this pipe is ,suflicient so that the gas bubbles through the liquid therein and does not lift slugs of liquid, as is the case in the smaller conduit l1.

Theammonia vapor from both the chambers H and I5 leaves the upper end of pipe I 8 and passes through the conduit 20.- Also, a certain amount of water vapor is inadvertently produced and flows along with the ammonia. In the rectifier 2| the temperatureof the ammonia and water vapor is reduced to a point sufliciently low to condense substantially all of the water vapor, but not low enough to condense the ammonia. The water drains back to the upper end of stand pipe l8, while the ammonia vapor continues through the conduit to the condenser 22.

In the condenser the temperature of the ammonia gas is reduced sufliciently to cause condensation at the pressure existing within the system. 'A certain amount of the ammonia is condensedin the upper part 23 of the condenser and drains into a vessel 25. However, the uncondensed portion of the'ammonia passes through the vessel in vapor form and continues through the lower part 24 of the condenser, where itis completely condensed and drains into vessel 26. The liquid ammonia from vessels 25 and 23 passes through conduits 3| and 32, respectively, to the parts 29 and 30 of the evaporator 21.

.As will presently be explained, hydrogen gas flows upwardly throughconduit 4| to the upper end of low temperature part 29 of the evaporator. The presence of the hydrogen in the evaporator part 29 causes the partial pressure of the, am-

' monia introduced through the conduit 3| to be reduced, in accordance with Daltons law, with a result that the ammonia evaporates, thus absorbing heat from the surroundings. The gaseous mixture of ammonia and hydrogen flows from.

the bottom of evaporator part 29 through conduit conduit 35. The conduit 34 is provided for the purpose of draining liquid from the lower end of evaporator part 29. Such liquid might be unevaporated ammonia or it might be water which was not completely separated from the refrigerant by the rectifler 2|. The mixture of ammonia and hydrogen flowing through conduit 35 has a low'temperature and, in flowing through inner pipe 31 of the heat exchanger 36 its temperature is raised by the warmer gas in jacket 38. Within the absorber 39 the mixture of ammonia and hydrogen is brought into intimate contact with weak absorption solution with the result that the ammonia is absorbed and .the' hydrogen passes through the absorber and through conduit 40 to the jacket 38.

The absorption process results in the production of heat which is transferred to the fluid contained in the gall in heat exchange relation with the absorber. The fluid in the coil 50 is thus caused to boil and the vapor passes through conduit 5| to the condenser 52 where its temperature is reduced sufficiently to liquefy it. The condensate flows through the conduit 53 to the lower end of coil 50.

The warm hydrogen flowing through jacket 38 serves to increase the temperature of the cold hydrogen-ammonia mixture within inner pipe 31, while at the same time the temperature of the hydrogen in jacket 38 is reduced. The hydrogen flows from the upper end of the jacket through conduit 4| to the low temperature part 29 of the evaporator.

The circulation of gases between and through the evaporator 21 and the absorber 29 results from the fact that the specific gravity of the mixture of ammonia and hydrogen flowing downwardly from the evaporator is greater than the specific gravity, of the substantially pure hydro- 33 to the upper end of evaporator part 30. At

this point additional refrigerant is introduced through conduit .32 and it evaporates in the presence of the hydrogen. However, the hydrogen which is introduced intothe evaporator part 30 already is admixed with the ammonia which evaporated in the part 29 and consequently the partial pressure of the ammonia in the part 30 is' not as low as in the part 29. Consequently, the temperature at which the refrigerant evaporates is higher in the part 3|!v than in the part 29.

The gaseous mixture of ammonia and hydro-- gen leaves the evaporator part 30 through the gen flowing upwardly from the absorber.

In Fig. 1, as just described,- the evaporator parts 29 and 30 have been shown as being located side by side. This has been done in order that the various connections may be clearly shown anddescribed. However, as pointed out in the introduction, it is desirable to have the lower temperature part 29 disposed within the higher temperature part 30. An evaporator constructed in this manner is illustrated in Figs. 2 through 5. As shown in these figures, the evaporator 21 includes an innercasting 50 and an outer,casting 5| which are secured in spaced relationship by means of bolts 62 extending through spacing sleeves 53. -Inner casting 60 is provided with a series of ice tray compartments 64 which are separated by means of shelves 55. The walls of casting 50 are formed with passages 65 through which extend conduits 51 which constitute the lower temperature part 29 of the evaporator. The upper end of conduit. is joined to conduit 4|, which supplies the hydrogen gas from the gas heat exchanger; The lower end of conduit 61 is connected by means of thefconduit 33 to the upper end of a conduit 58 which'is receivedwithin passages 69 formed in the outer casting 8|. Conduits 61 and 58 extend in ser-- pentine form throughthe passages 69 formed in the casting and the lower end of conduit 631s connected to the conduit 35 leading to the inner monia issupplied to the upper end ofconduit 51 through the conduit 3|, while liquid ammonia is supplied to the upper end ofconduit 68 through the conduit 32, as is clearly shownin Fig. v3.

, A'plate 10 issecured to the front ends of casting 60 and GI and is provided with an opening II in alignment with inner casting 60. A door 12 is hinged to plate 10' and serves to give access to the ice tray compartment 64. A series of heat able for the transfer of heat between the air within the cabinet 28 and the casting.

The circulation of fluids through the coils 61' and 68 of the evaporator shown in Figs? through 5 is the same as that described in connection with Fig. land hence need not be repeated. Due to the fact that the low temperature coil 61 is surrounded by the higher temperature coil 68, it is protected from the transfer of heat thereto from the comparatively warmair within the cabinet 28. Furthermore, a very low temperature may be maintained within the ice compartment without causing the temperature in the cabinet to fall to an'undesirably low value.

It will be understood that the apparatus herein disclosed is given by way of example only and that modifications thereof fall within the scope of my invention, which is to be determined by th appended claims.

What is claimed is: 1

1. In an absorption refrigerating apparatus, a condenser, an absorber, a high temperature evaporator, a low temperature evaporator within said high temperature evaporator, means for supplying refrigerant from said condenser to both of said evaporators, means for supplying an inert gas from said absorber to said low temperature evaporator, and means for conveying a mixture of inert gas and gaseous refrigerant from said low temperature evaporator to said high temperature evaporator.

2. In an absorption refrigerating apparatus, a

condenser, an absorber, a high temperature evaporator, a low temperature evaporator within said high temperature evaporator, means for supporting an ice tray within said low temperature evaporator, means for supplying refrigerant from said condenser to both of said evaporators, means for supplying an inert gas from said absorber to said low temperature evaporator, and means for conveying a mixture of gaseous refrigerant and inert gas from said low temperature evaporato to said high temperature evaporator.

3. In an absorption refrigeration apparatus, an i insulated cabinet providing a food storage space, a condenser and an absorber outside of said space, a high temperature evaporator within said space, a low-temperature evaporator within said high temperature evaporator, means for supporting an ice tray within said low temperature evaporator, means for supplying refrigerant from said condenser to both of said evaporators, mean for supplying an inert gas from said absorber to said high temperature evaporator, and means for conveying a mixture of gaseous refrigerant from said low temperature evaporator to said high temperature evaporator.

4. In an absorption refrigerating apparatus, a generator, a condenser, a high temperature evaporator, a low temperature evaporator within said high temperature evaporator, an absorber, means for conveying vaporous refrigerant from said generator to the upper end of said condenser, means for conveying liquid refrigerant from the lower end of said condenser to said high temperature evaporator, means for withdrawing liquid refrigerant from an intermediate point in said condenser and conveying it to said low. temperature evaporator, means for conveying inert gas from said absorber to said low temperature evaporator, and means for conveying a mixture of gaseous refrigerant and inert gas from said low temperature evaporator to said high temperature evaporator.

5. In an absorption refrigerating apparatus, a condenser, an absorber, ,a high temperature evaporator, a lowtemperature evaporator within said high temperature evaporator, means for supplying refrigerant from said condenser to the upper ends of both of said evaporators, means for supplying inert gas from said absorber to the upper end of said low temperature evaporator, means for conveying a mixture of gaseous refrigerant and inert gas from the lower end of said low temperature evaporator to the upper end of said high temperature evaporator, and means for conveying a gaseous mixture from the lower end of said high temperature evaporator to said absorber.

6. In an absorption refrigerating apparatus, a condenser, an absorber, a high temperature evaporator, a low temperature evaporator within said high temperature evaporator, means for supplying refrigerant from said condenser to the up.- per ends of both of said evaporators, means for supplying inert gas from said absorber to the upper end of said low temperature evaporator, means for conveying a mixture of gaseous refrigerant and inert gas from the lower end of said low temperature evaporator to the upper end of said high temperature evaporator, conduit means connecting the lower end of said high temperature evaporator with said absorber, and means for draining liquid from the lower end of said low temperature evaporator to said absorber.

'7. In an absorption refrigerating apparatus, a condenser, an absorber, a high temperature evaporator, a low temperature evaporator within said high temperature evaporator, means for supplying refrigerant from said condenser to the upper ends of both of said evaporators, means for supplying inert gas from said absorber to the upper end of said low temperature evaporator,

means for conveying a mixture of gaseous refrigerant and inert gas from the lower end of said low temperature evaporator to the upper end of said high temperature evaporator, conduit means,

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