US2325706A - Refrigerating apparatus - Google Patents

Description

1943- 1.. A. PHILIPP 2,325,706

REFRIGERATING APPARATUS Filed April 12, 1941 2 Sheets-Sheet 1 INVENTOR. Lqwezncr. fl. Pmurr aw-9km) Patented Aug. 3, 1943 REFRIGERATING APPARATUS Lawrence A. Philipp, Detroit, Mich., assignor to Nash-Kelvinator Corporation, Detroit, Mich., a

corporation of Maryland Application April 12, 1941, Serial No. 388,253

3 Claims.

This invention relates to refrigerating apparatus, and, more particularly, to refrigerant evaporators.

One of the objects of my invention is to provide an improved refrigerant evaporator for freezing substances and for cooling the circulating air within a refrigerator cabinet.

Another object of my invention is to provide an improved refrigerant evaporating unit which comprises a non-flooded refrigerant evaporating section and a flooded refrigerant evaporating section arranged together in the form of a U and connected to each other by two spaced apart refrigerant manifolds having restricted passages therebetween for conducting refrigerant from the non-flooded section to the flooded section in a uniform and evenly distributed flow.

Another object of my invention is to provide an improvedrefrigerant evaporator which comprises a serpentine refrigerant evaporating conduit connected in series to a plurality of parallel refrigerant evaporating passages by means of two spaced apart refrigerant manifolds having restricted passages therebetween which serve to conduct refrigerant from the serpentine conduit to the refrigerant passages, said serpentine conduit and refrigerant passages being arranged in U-shaped conformation to enclose a freezing zone and to present surfaces for cooling the circulating air within a refrigerator cabinet.

Another object of my invention is to provide an'improved refrigerant evaporator which comprises two sheets of metal formed to provide a plurality of refrigerant evaporating passages arranged in parallel flow relationship and having an outlet header and an inlet refrigerant distributing manifold, and a serpentine refrigerant evaporating conduit connected to the distributing manifold by means of restricted passages whereby refrigerant from the serpentine conduit is injected into the distributing manifold at a number of points for uniform distribution throughout the refrigerant passages.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of th present invention is clearly shown.

Fig. 1 is a perspective view of my improved evaporator in schematic arrangement with a refrigerating system;

Fig. 2 is a perspective view of the same evaporator shown in Fig. 1 with the opposite side in the foreground;

Fig. 3 is a transverse cross-sectional view of the evaporator taken on line 3-3 of Fig. 1;

Fig. 4 is a plan view of the sheet metal portions of the evaporator shown in Fig. 1 prior to bending;

Fig. 5 is a plan view of the sheet metal portions of a modified embodiment of my evaporator prior to bending;

Fig. 6 is a longitudinal View in cross section of the modified evaporator taken along line 66 of Fig. 5;

Fig. 7 is a transverse cross-sectional view of the modified evaporator shown in Fig. 5 after bending taken along line of Fig. 5 with a refrigerated shelf included;

Fig. 8 is a longitudinal view in cross-section of another modification of my evaporator be-' fore bending; and

. Fig. 9 is an end view in elevation of the modified evaporator shown in Fig. 8 after bending into final form and with a refrigerated shelf included.

In accordance with my invention, I have provided an improved refrigerant evaporating unit for freezing purposes and for cooling the circulating air within a refrigerator cabinet. This unit comprises two sheets of metal of U-shaped conformation formed to provide a non-flooded refrigerant evaporating section and a flooded refrigerant evaporating section. These two sections are connected to each other by two spaced apart refrigerant manifolds having at spaced points a plurality of restricted passages therebetween. The non-flooded section preferably consists of a serpentine conduit or passage arranged in an L-shaped conformation and connected to one of the refrigerant manifolds while the flooded section preferably consists of a plurality of parallel refrigerant passages extending between an outlet header and the other of the refrigerant manifolds and also arranged in an L-shaped conformation. Refrigerant is supplied to the non-flooded section first and is then introduced into the flooded section by means of the two manifolds connected by the restricted passages. By this arrangement, a uniform and balanced distribution of refrigerant is obtained throughout both the flooded and the non-flooded sections so that a uniform freezing temperature may be maintained within the evaporator while an air-cooling surface of substantially uniform temperature is presented to the circulating air within the refrigerator cabinet.

Referring to the drawings, there is illustrated a refrigerating apparatus Ill comprising a compressor-condenser unit II and an evaporator l2 which is adapted to be positioned within an enclosed compartment that is to be cooled. The compressor-condenser unit ll includes a motorcompressor unit l4 and a condenser IS. A conduit l6 connects the discharge side of the compressor to the condenser I and a small diameter or capillary tube l1 connects the discharge side of the condenser with the evaporator l2 A conduit connects the outlet side of the evaporator l2 with the suction side of the compressor unit l4. A portion of the length of the conduits I! and 20 are in thermal or heat exchange relationship as at 22. Suitable controls, not shown, may be employed for controlling the cycle of operations of the motor-compressor unit M which during the onphase withdraws refrigerant vapor from the evaporator I2 through the conduit 20 into the compressor where it is compressed and then discharged through conduit !6 into condenser i5 to be cooled, liquefied and returned through conduit I! to the evaporator. The diameter of the conduit I1 is such as to meter the flow of liquid refrigerant therethrough in predetermined quan titles. The refrigerant in conduit I1 is further cooled by thermal exchange with the returning refrigerant vapor in conduit 20.

The evaporator l2 comprises two sheets: of metal 24 and 25 bent in the form of a U and nested one within the other, the outer sheet 24 being embossed to form refrigerant circulating passages when Welded or soldered to the inner sheet 25. Embossed in the outer sheet is a serpentine refrigerant conveying conduit 26 which includes a plurality of convolutions 28 running up and down one side of the evaporator and over a portion of the bottom. Embossed in the other side of the evaporator is a plurality of parallel refrigerant passages 30 which substantially cover the side of the evaporator and the remaining portion of the bottom. These passages are provided at their upper ends with an outlet header 32 formed by embossing both the inner and outer sheets and at the lower end with a distributing manifold 34 formed in the outer sheet 24. Between the .lowerends of the serpentine conduit 26- and the distributing manifold 34 there is embossed in the outer sheet a refrigerant receiving manifold 36 in spaced relationship to the distributing manifold. Between this manifold 36 and the distributing manifold 34 a plurality of restricted passages 38 are provided for conveying refrigerant from the receiving manifold to the distributing manifold. These restricted passages are preferably spaced at regular intervals so that refrigerant from the receiving manifold 36 is injected uniformly throughout the length of the I manner as by welding or soldering to the under "Side of the shelf 43. This conduit is directly connected at one end to the small diameter tube I! at the rear of the shelf and at the other end by means of a short conduit 48 to the serpentine conduit 26. Brackets 50 are provided at the top of the evaporator for supporting it within the. cooling compartment of the refrigerator.

In operation, my improved evaporator provides a uniform and effective distribution of liquid refrigerant on two sides and the bottom of the nested U-shaped sheets of metal. Refrigerant is admitted to the serpentine conduit 26 from the shelf conduit 46. If first circulates preferably to the front of the evaporator and then up and down one side of the evaporator and across a portion of the bottom to provide uniform effective cooling throughout that side and bottom. The liquid refrigerant and refrigerant vapor enter the receiving manifold 36,where because of the restricted passages 38 a pack pressure is built up. As a result refrigerant from the receiving manifold enters the distributing manifold 34 in substantially equal amounts through the restricted passages 38 at regularly spaced intervals throughout the distributing manifold. From the distributing manifold the refrigerant is distributed to the several refrigerant passages 30 in substantially uniform and equal quantities, thereby producing a uniform upward flow of refrigerant through all the parallel refrigerant passages. Because of the number of passages and because of the uniform distribution of refrigerant throughout the passages, an eifective and uniform heat transfer surface is provided. The refrigerant circulates into the outlet header 32 from which evaporated refrigerant is returned to the compressor-condenser unit by the suction conduit 20. Thus it will be seen that I have provided a refrigerant evaporator comprising two sheets of metal formed to provide a single serpentine passage connected in series relationship with a plurality of parallel refrigerant passages in such manner that'refrigerant from the serpentine passage is circulated concurrently and uniformly up through the parallel passages to provide effective heat transfer surfaces of sub stantially the same temperature.

In Figs. 5, 6 and 7 there is shown a modification of my improved evaporator. It comprises two sheets of metal, an inner sheet 50 and an outer sheet 52. The outer sheet 52 is embossed to form refrigerant circulating passages when secured as by soldering or Welding to the inner sheet 56. The sheets are preferably bent into U-shaped conformation to provide a freezing compartment and an air cooling surface. In this modification, the outer sheet of metal is somewhat shorter than the inner sheet so that the inner sheet extends beyond the outer sheet on one side of the evaporator as at 54. This portion of the inner sheet is embossed as at 56 to give added rigidity. The outer sheet is embossed to provide a serpentine passage 56 which opens into a refrigerant receiving manifold 60. The rest of the outer sheet is embossed to provide a header 62, an outlet manifold 64, an inlet distributing manifold 66 and parallel refrigerant passages 66 running between the inlet manifold 66 and the outlet manifold 64. The refrigerant receiving manifold 60 is connected to the refrigerant distributing manifold 66 as in the preferred embodiment by means of restricted passages 10 spaced at regular intervals along the distributing manifold. The outlet manifold 64 in this embodiment is preferably spaced from the outlet header 62 so that when the sheet metal portions are bent in U-shaped conformation this outlet manifold lies in the same horizontal plane as the uppermost part of the serpentine conduit 58. i This outlet manifold is connected to the outlet header 62 by means of conduits I2 and 14. The space in the outer sheet 52 between the manifold and th header is preferably embossed to give added rigidity there-- between. Shelves 15 and 16 are provided within the evaporator for supporting receptacles of substances to be frozen. A serpentine conduit 11 serves to refrigerate shelf 16. In this modification a more limited heat transfer surface is provided by the above arrangement of the refrigerant circulating passages. Otherwise the operation is the same as that of the preferred embodiment. Refrigerant is admitted from the refrigerated shelf 16 into the serpentine conduit 58 which extends only part way up one side of theevaporator and across a small portion of the bottom. Refrigerant leaving the serpentine conduit is injected from the receiving manifold 60 into the distributing manifold 66 of the parallel passages 68 which extend across the remaining portion of the bottom of the evaporator and part way up the other side to the outlet manifold 64. Evaporated refrigerant and whatever unevaporated refrigerant there may be is circulated to the header 62 from which the evaporated refrigerant is conducted back to the compressor unit. Thus it will be seen that a substantial part of both sides of the evaporator is left unrefrigerated thereby providing an evaporator which in conjunction with the refrigerated shelf is adapted to maintain a large freezing zone while presenting only a small air cooling surface. Such an evaporator is particularly adapted to be used for cooling a compartment in conjunction with another cooling unit such as a secondary evaporator. I

In Figs. 8 and 9 there is shown another modification of my improved evaporator. In this modification which corresponds substantially with that illustrated in Figs. 5, 6 and 7, an outlet header 80 is provided which instead of being located as in the modification shown in Figs. 5, 6 and 7, is placed where the outlet manifold 64 is located and the outlet manifold 64 itself is eliminated. Otherwise the two evaporators correspond and corresponding numbers indicate corresponding parts.

Although only a preferred form of the invention has been illustrated, and that form described in detail, it will be apparent to those skilled in the art that various modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. A U-shaped refrigerant evaporator comprising two sheets of metal formed to provide a serpentine refrigerant conduit in one side and a portion of the bottom thereof, a plurality of refrigerant passages extending up the other side and across the remaining portion of the bottom, said refrigerant passages being provided at their upper ends with an outlet header and at their lower ends with an inlet manifold, and restricted passages for injecting refrigerant from said serpentine conduit into said inlet manifold.

2. A refrigerant evaporating unit comprising.

an L-shaped non-flooded refrigerant evaporating section, an L-shaped flooded refrigerant evaporating section, two spaced apart refrigerant manifolds, one in direct communication with said non-flooded section and the other in direct communication with said flooded section, and injecting means directly connecting between said manifolds for conducting refrigerant from said non-flooded section to said flooded section.

3. A refrigerant evaporating unit of box-like conformation comprising a non-flooded serpentine refrigerant passage for cooling the top wall, an L-shaped non-flooded refrigerant evaporating section for cooling the lower portion of a side wall and a portion of the bottom wall, an L-shaped flooded refrigerant evaporating section for cooling the lower portion of another side wall and the remaining portion of the bottom wall, two spaced apart refrigerant manifolds one in communication with said non-flooded refrigerant section and the other in communication with said flooded section and injecting means directly connecting said manifolds for conducting refrigerant from said non-flooded section to said flooded section.

LAWRENCE A. PEELIPP.

Images