US2056023A

US2056023A - Heat exchange apparatus

Info

Publication number: US2056023A
Application number: US759673A
Authority: US
Inventors: Jr Alexander R Stevenson
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1934-12-29
Filing date: 1934-12-29
Publication date: 1936-09-29
Anticipated expiration: 1953-09-29

Description

Sept. 29, 1936. A. R STEVENSON. JR 2,056,023

HEAT EXCHANGE APPARATUS Filed Dec. 29, 1954 Inventor: Alexcrrwder`l F?. Stevehs0h,JT3,

Patented Sept.` 29, 1936 HEAT EXCHANGE APPARATUS Alexander R. Stevenson, Jr., Schenectady, N. Y.,

assignor to General Electric Company, a corporation of New York Application December Z9, 1934, Serial No. 759,673

11 Claims.

My invention relates to heat exchange apparatus suitable for use in refrigerating machines.

It is an object of my invention to provide an improved heat exchange device of the type in which heat is transferred between a casing or other body and a fluid medium.

Another object of my invention is to provide an improved arrangement for circulating a fluid medium about a heat exchange device.

A further object of my invention isf to provide an improved air circulating and frost removing device for refrigerator evaporators.

Further objects and advantages of my invention will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to land forming apart of this specification.

For a better understanding of my invention reference may be had to the accompanying drawing in which Fig. 1 is a sectional view of a household refrigerator provided with a heat exchange device embodying my invention; Fig. 2 is a sectional view along the line 2-2 of Fig. 1; Fig. 3 is a sectional view along the line 3-3 in Fig. 1, and Fig. 4 is a diagrammatic view of another embodiment of my invention.

Referring now to the drawing, in Figs. 1, 2 and 3 I have shown a refrigerator cabinet having an outer metal wall I Il, a compartment II to be cooled, an evaporator compartment I2 and a motor and compressor compartment I3. The compartments II and I2 are formed by inner metal liners Il and I5 respectively and are surrounded by thermal insulation I6. The compartment I3 is not thermally insulated and is provided with louvers l1 formed in the outer side walls I0 of the cabinet to admit air to cool the motor and condenser. The refrigerating machine is of the general type shown and described in U. S. Letters Patent No. 1,155,780 granted to Audiilren and Singrn on October 15, 1915. 'I'he machine comprises a compression casing I8 and an evaporator I9 secured together on a hollow shaft 20 which is mounted to rotate in bearing brackets 2I and 22 and is driven by a motor 23 through a belt 24. When the compressor and evaporator are rotated by the motor 23 gaseous refrigerant is compressed by a compressor within the casing Il and is cooled and liqueed by the circulation of air over the casing. The liquid refrigerant passes through a conduit arranged in the hollow shaft 20 to. the evaporator I9 where it is vaporized upon the absorption of heat from the chamber I2, the vaporized refrigerant being returned to the compressor.

From the foregoing it will be apparent that it is necessary to provide an efficient transfer of heat between the evaporator and the compressor 5 casings and the air surrounding them, and also that it is necessary to drive the cooled air from the evaporator compartment I2 into the 'compartment I I and to circulate cooling air over the compressor and condenser.

In accordance with my invention, I provide a plurality of spaced parallel fins 25 on the evaporator I9 and a plurality of spaced parallel ns 26 on the compressor casing I8, the fins being arranged circumferentially about the evaporator 15 and compressor casing and perpendicular to the axis of rotation. When the evaporator and compressor casings are rotated the fins induce a circulation of the surrounding air. In order to use this circulation of air to provide an eillcient 20 transfer of heat between the casings and the surrounding air, and in order to circulate air through the compartments II and I3, I provide baille plates 21 and 28 in the compartments I2 and I3 respectively and secured to the walls thereof. 25 These bailles are comb-like in appearance and have teeth 29 and 30' which ilt between the

fins

25 and 26 respectively. The

teeth

25 and 30 and the bailles 21 and 28 are arranged closely adjacent the evaporator I9 and the casing I8, the 30 space shown between them on the drawing being exaggerated for purposes of illustration. It will be apparent that, as theevaporator I9 and the casing I8 are rotated, the air circulated by such rotation will be diverted or skimmed oiI by 35 the baffles 21 and 28 and will ow away from the casings and, since the compartments I2 and I3 are each divided by the bafiies on one side of the shaft 20, the currents of air produced will clrculate across the compartments on the opposite`40 side of the shaft. In order to utilize the circulation of air in the compartment I2 to cool the compartment Il, I-provide a semi-cylindrical or arcuate baille 3|, as shown in Fig. 2, extending across the compartment I2, surroundingthe up- 45 per portion of the evaporator I9 and secured to the liner I5 on a leg 32. I also provide supply and

discharge passages

33 and 34, respectively, opening into the compartment II on opposite sides of a baille 35 extending across the compart- 50 ment and terminating short of the top thereof. Upon reference toFig. 2, it will be apparent that when the evaporator I9 is rotated in a counterclockwise direction, as indicated by the arrow I8a. the air will be drawn downwardly from the open- 55 ing 34 into the compartment I2 and will be forced across the compartment by the fins 25 on the evaporator I9, the path of the air being indicated by arrows in the Fig'. 2. The air is cooled in circulating from one side of the compartment to the other over the fins 25 and the surface of the evaporator I9 and will then flow upwardly through the opening 33 into the compartment Il, wherein it will circulate up over the baille 35 and return downwardly on the other side to the passage 34. Frost which may be collected on the evaporator I9 due to the condensation and freezing of moisture thereon will be scraped off by the baille 21 and will fall to the bottom of the compartment from whence it may be removed.

, It is readily apparent that the formation of such frost will insure a very small clearance between the baille 21 and the fins 25 and will thereby provide an efficient circulation of air and a minimum film of air between the baille and the evaporator. The position of the baille 21` may be selected to direct the air as desired, and also to remove the frost so that it will be collected where it may be conveniently removed. IIn the cabinet shown the compartment yI2 is provided with a door 36 which may be opened to afford access thereto.

The circulation of air over the compressor casing I8 is accomplished in a manner similar to that employed for the evaporator. When the casing I8 is rotated in a clockwise direction, as shown, air will be drawn through the louvers I1 at the right-hand side of Fig. 3, will be driven through the compartment I3 by operation of the fins 26, and will leave by way of the louvers I1 at the left-hand side of the casing so as to cool the condenser, and also the motor 23. The path of circulation of the air is indicated by arrows.

'I'his arrangement for circulatingl air minimizes the effect due to the presence of a stagnant insulating film of air closely adjacent the surface Y of the evaporator and the compressor casings and, for this reason, produces a highly efficient transfer of heat between the casings and the air.

In Fig. 4 I have shown diagrammatically a modification of my invention in which the evaporator is maintained stationary while the baffles or scraping blades are rotated. The refrigerating machine shown comprises a compressor 31 driven by a motor 33 through a belt 39. Gaseous refrigerant is compressed by the compressor 31 and flows to a condenserI 40 wherein it is liquefied and flows in predetermined quantities through a valve 4I to an evaporator comprising hollow plates 42 and 43 spaced apart and having smooth inner surfaces. Refrigerant vaporized within the evaporator is returned to the compressor through a suction line 44. In order to provide an emcient circulation of air over the surface of the evaporator, I provide a plurality of baiiies or blades 45 driven by a shaft 46 which is an extension of the shaft of the compressor 31. Theseblades are arranged to rotate closely adjacent the smooth surface of the evaporator plates 42 and 43, and as they rotate produce a rapid circulation of air about the evaporators and also prevent the accumulation of any substantial amount of frost thereon. It is evident that if desired other blades may be provided to rotate adjacent the outer surface'of the evaporator to further increase the circulation of air and prevent excessive collection of frost. Theblades i5 may obviously be driven by a separate motor should it be desired to maintain them in opera tion continuously regardless of the operation of the compressor.

From the foregoing it is apparent that I have provided a highly efilcient arrangement for transferring heat between the surfaces of a rigid heat exchange body and a iiuid medium surrounding that body.

Although I have shown particular embodiments of my invention as applied to refrigerating machines, further modifications will become apparent to those skilled in the art. I do not, therefore, desire my invention rto be limited to the particular arrangement shown and described, and I intend in the appended ,claims to cover all modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A heat exchange device including a body having a fluid therein, a plurality of parallel fins on said body and arranged circumferentially about the same, and means including a baille having a portion thereof arranged between said fins for producing a turbulent flow of cooling fluid about said ns, said body and said baille being relatively rotatable.

2. A heat exchange device including a body having a fluid therein, a plurality lof parallel fins on said body yand arranged circumferentially about the same, and means including a baille having portions adjacent the sides of said fins for producing a turbulent `,flow of cooling duid about said fins, said body and said baille being relatively rotatable.

3. A heat exchange device including a body having a fluid therein, a plurality of parallel fins on said body and arranged circumferentially about the same, and means including a baiiie having portions adjacent the sides of said fins and adjacent7 the surface of said body for producing aturbulent ow of cooling fluid about said fins and said body, said body and said bame be- -ing fluid about said ns and for removing foreign matter Vfrom the fins and the surface of said body, said body and said comb-like baille being relatively rotatable.

5. An evaporator for refrigerating machines including a body having refrigerant therein, a plurality of parallel fins on said body and arranged circumferentially about the same, and means including a baille having portions arranged between said fins for producing a turbulent flow of uid about said evaporator and for removing frost or foreign matter from the surface of said evaporator, said body and said baille being relatively rotatable. f

6. A heat exchange device including abody having a fluid therein, a cabinet providing a compartment surrounding said body, a plurality of parallel fins on said body and arranged circumferentially about the same, and means including a baffle secured to the walls of said compartment and having portions adjacent the sides of said fins and adjacent the surface of said body for producing a turbulent flow of cooling fluid about said fins and said body, said body and said baille being relatively rotatable.

7. A heat exchange device including a body having a fluid therein, a cabinet providing a compartment surrounding said body, a plurality of parallel fins on said body and arranged circumferentially about the same, means including a baille having portions adjacent the sides of said ns and adjacent the surface of said body for producing a flow of cooling fluid about said ns and said body, said body and said baille being relatively rotatable, and means including an arcuate baille secured to the walls of said compartment for directing the circulation of said cooling fluid through said compartment from one side to the other side thereof.

8. A refrigerating machine including a compressor casing and an evaporator arranged for rotation about a common axis, a plurality of parallel ns on said compressor casing and `arranged circumferentially about the same, a plu- .rality of parallel fins on said evaporator andarranged circumferentially about the same, and means including bailles having portions arranged between said fins for producing a circulation of air about said casing and about said evaporator.

9. A heat exchange device including a body having a vaporizable refrigerant therein, a cabinet provided with a food storage compartment, a plurality of parallelfins on said body arranged circumferentially about the same, means including a baille having portions adjacent the sides of said ns and adjacent the surface of said body for providing a turbulent ilow of air about said body, said body and said baille being relatively rotatable, an-d means utilizing the movement of air caused by the relative movement of said body and said baille for directing a stream of cooled air through said food storage compartment.

10. A heat exchange device including a body having a vaporizable refrigerant therein, a cabinet provided with a food storage compartment, a baille extending vertically upward in said food storage compartment, the upper end of said baille being spaced from the top wall of said food storage compartment, a plurality of parallel ns on saidbody and arranged circumferentially about the same, means including a second baille having portions adjacent the sides of said fins and adjacent the surface of said body for providing a turbulent ilow of air about said body, said body and said second baille being relatively rotatable, and means utilizing the movement of air caused by the relative movement of said body and said second baille for directing a stream or" cooled air through said food storage compartment, said lastmentioned means including an air supply conduit extending from one side of said baille in said food storage compartment adjacent said body and an air discharge conduit extending from adjacent said body to the opposite side of said baille in said food storage compartment.

11. A heat exchange device including an evaporator having a vaporizable refrigerant therein, a cabinet provided with a food storage compartment and an evaporator compartment, a plurality of parallel fins on said evaporator and arranged circumferentially about the same, means inc1ud ing a baille having portions adjacent the sides of said iins and adjacent the surface of said evapo- .rator for providing a turbulent ilow of air about ALEXANDER R. s'rEvENsoN,y JR.