US2073092A

US2073092A - Refrigeration apparatus

Info

Publication number: US2073092A
Application number: US37483A
Authority: US
Inventors: Harry K Bergholm
Original assignee: Servel Inc
Current assignee: Servel Inc
Priority date: 1933-04-11
Filing date: 1935-08-23
Publication date: 1937-03-09
Anticipated expiration: 1954-03-09

Description

REFRIGERATION APPARATUS Original Filed April 11, 1933 2 Sheets-Sheet 1 I I g INVENTOR.

v w N BY ATTORNEY.

March 9, 1937. K BERGHQLM" 2,073,092

REFRIGERATION APPARATUS Original Filed April 11, 1933 2 Sheets-Sheet 2 ATTORNEY. w

Patented Mar. 9, 1937 UNITED STATES PATENT OFFICE REFRIGERATION APPARATUS Original application April 11, 1933, Serial No. 665,501. Divided and this application August 23, 1935, Serial No. 3?,483

7 Claims.

My invention relates to a rectifier for absorption refrigeration apparatus and it is an object of the invention to provide an air cooled rectifier operative without decrease in efiiciency through- 5 out a wide range of room temperatures and thermal inputs. This application is a division (giggly application Serial No. 665,501 filed April 11,

The invention, together with the objects and 10 advantages thereof, will appear upon consideration of the following description taken in conjunction with the accompanying drawings, of which:

Fig. 1 is a side elevation, partly in vertical sec- 15 tion, of a rectifier embodying the invention;

Fig. 2 is a top plan view, partly in horizontal section, of the rectifier shown in Fig. 1;

Fig. 3 is a sectional view taken on the line 3-3 in Fig. 1;

Fig. 4 shows diagrammatically an air cooled 20 absorption refrigeration system provided with the rectifier; and

Fig. 5 is a side elevation, partly in vertical section, of a known rectifier for comparison with that shown in Fig. 4.

Referring to Figs. 1, 2, and 3 of the drawings, a rectifier It] comprises a pipe which, for the purpose of explaining the invention, I have indicated as consisting of a first part H, a second part I3,

30 a loop l4, and a third part I5. The parts H and I3 are formed by a continuously straight portion of the pipe which is inclined slightly downwardly to the right as seen in Fig. 1. The part I5 is arranged by forming the loop l4, alongside of part 5 l3 and inclined slightly downwardly to the left as seen in Fig. 1. The first part I l is provided with heat radiation fins i2. The parts l3 and [5 are imbedded in a metal casting H3. The casting I6 provides a good thermal conduction between the parts l3 and I5 and, therefore, is preferably of aluminum. The casting I6 is provided with, or may be formed with heat radiation fins l1. The fins H are arranged in thermal conductive relation with only that portion of the casting l6 5 which is adjacent the part l5 of the pipe. The fins H are formed with openings l8 next to the remaining portion of the casting l6. Thus, the part 15 is included in the path of thermal conduction from the part l3 to the fins IT. The end IQ of the rectifier I 0 will be referred to as the inlet, and the other end 20 will be referred to as the outlet.

Referring now to Fig. 4 of the drawings, the rectifier i0 is shown connected in a continuous '55 absorption refrigeration system of a pressure equalized type, as generally disclosed in Patent 1,609,334 to von Platen et ai. Operation of the particular system illustrated is briefly as follows:

In a generator 2 l, ammonia vapor is expelled by heat from the water solution of ammonia contained in the generator. Ammonia vapor passes to the inlet 19 of the rectifier In. In the rectifier, water vapor condenses out of the ammonia and drains back to the generator. The ammonia vapor passes from the outlet 20 of the rectifier into an air cooled condenser 22. In the condenser, the ammonia vapor is liquefled and the liquid ammonia drains into vessel 23. From the lower part of the vessel 23, the liquid ammonia overflows through a conduit 24 into an evaporator 25 where it evaporates and difiuses into hydrogen which enters the evaporator through conduit 3|. The resulting gas mixture flows from the evaporator through conduit 26, a gas heat exchanger 21, and. a conduit 28 into an absorber 34. Here the ammonia is absorbed out of the gas mixture into weakened solution which enters the absorber through a conduit 29. The resulting weak gas returns from the absorber to the evaporator through a conduit 30, the gas heat exchanger 21, and the conduit 3!. The enriched solution flows from the absorber through a conduit 35, a liquid heat exchanger 33, and a thermosyphon conduit 36 into the generator 2!. The weakened solution flows from the generator 2| to the absorber 34 30 through a conduit 32, the liquid heat exchanger 33 and the conduit 29.

The absorber 34 is cooled by,a system comprising a cooling coil 31 around the absorber and a condenser 38, the cooling coil and condenser 35 being interconnected to form a closed circuit which contains a suitable cooling fluid, such as methyl chloride, which evaporates in the coil 31 and liquefies in the air cooled condenser 38, thus providing a vaporization-condensation cycle for transferring heat from the absorber to the air.

The condenser 22 is vented to the gas circuit to return trapped hydrogen. A vent is provided by a conduit 39 connected from the upper part of the vessel 23 to the absorber 34 and having an enlarged chamber which may be referred to as a pressure vessel 40. The pressure vessel pro vides storage space forauxiliary hydrogen which is displaced into the gas circuit between the absorber and evaporator at high air temperatures, thereby increasing the total pressure in the system so that the latter varies in accordance with room temperature.

For the purpose 01' better understanding the present invention, assume, for the present, that a known recifler 4|, as illustrated in Fig. 5, is connected in the above described system in place of the improved rectifier ID. The rectifier 4! is provided with heat radiation fins 42, and is of such length that all of the water vapor is condensed out of the ammonia before the latter enters the condenser 22 when the system is operating with maximum heat input at maximum room temperature. If the rectifier 4! should be too short, some water vapor will pass into the condenser and evaporator, involving a heat loss or decrease in refrigerating efficiency. When this system is operating with a low heat input at low room temperature, all the water vapor will have been condensed out of the ammonia in the first part of the rectifier 4|. At minimum room temperature with minimum heat input, all of the water vapor may be condensed in the first half of the rectifier 4i, and in the remaining length of the rectifier ammonia vapor will condense, the liquid ammonia draining back to the generator through the rectifier inlet i 9, thus decreasing the efilciency of the system.

In accordance with my invention, however, the improved rectifier i0 is connected in the system shown in Fig. 4. in place of the known rectifier 4 I The first part it of the rectifier i0 is so dimensioned that at minimum room temperature with minimum heat input all water vapor will be removed from the gas but no condensation of ammonia will take place. The second part i3 is cooled by the fins I! only by conduction of heat through the third section I5. It will now be clear that there must be a temperature drop from the rectifier section l3 to the third section i5 and that the section 13 will always be at a temperature above that of section [5. When the rectifier section i5 is cooled to a sufficiently low temperature, it functions as a condenser for the ammonia vapor, and under such conditions may be considered as a condenser, for instance, the first part of condenser 22. It will now be further understood that the rectifier section I3, being at a higher temperature than the section i5, must always remain at a temperature above the condensing temperature of ammonia. Liquid formed in parts it and id of my rectifier drains back to the generator. Liquid formed in the part l5, however, drains to the condenser 22. Thus, all the water vapor will be removed from the ammonia in the rectifier ii) at maximum room temperature with maximum heat input, but at minimum temperature with low heat input no ammonia will be condensed where it can drain back to the generator.

It will be understood that various changes may be made within the scope of the invention which is not limited except as indicated in the following claims.

What is claimed is:

1. A rectifier for an absorption refrigeration system having portions arranged for flow of liquid in opposite directions, heat radiation means, and means for transferring heat from one of said portions to said radiation means by conduction in a thermal path including another of said portions.

2. A rectifier for an absorption refrigeration system having portions arranged for flow of liquid in opposite directions, and means for conveying heat from one of said portions by conduction in a thermal path including another of said portions.-

3. A rectifier comprising an inclined tube, heat radiating fins on the lower part of said tube, a second tube having one end connected to the upper end of said first tube, and an aluminum casting embedding the upper part of said first tube and said second tube, said casting being provided with integral heat radiating fins extending from that portion adjacent said second tube.

4. A rectifier for an absorption refrigeration system including a looped conduit having the portions on opposite sides of the loop in thermal exchange relation and arranged for fiow of liquid in opposite directions in said conduit, and heat radiation means directly associated with only one of said portions.

5. A rectifier for an absorption refrigeration system including a looped conduit having portions on opposite sides of the loop embedded in a body of thermal conductive material and arranged for flow of liquid in opposite directions in said conduit, said body having a heat radiation surface for air cooling adjacent one of said portions and remote from the other of said portions.

6. A rectifier for an absorption refrigeration system including a conduit having a first portion provided with extensive heat radiation surface for air cooling and a. second portion and a third portion, means providing a further heat radiation surface for air cooling, and means providing a thermal conductive path to said further heat radiation surface from said second portion of said rectifier conduit intermediate said first and third portions, said third portion being located wholly in said path between said second portion and said further radiation surface.

7. A rectifier for an absorption refrigeration system including a conduit having a plurality of portions each constructed and arranged for transfer of heat from within by conduction and radiation to a cooling medium outside, two of said portions having a common path for conduction of heat to a common radiation surface, one of said two portions being located wholly between the other of said two portions and said radiation surface whereby said other of the two portions remains at a temperature above that of the first of saidtwo portions.

HARRY K. BERGHOLM.