US2136249A - Refrigerant evaporator - Google Patents

Description

Ndv. 8, 1938 D. F. NEWMAN REFRIGERANT EVAPORATOR Filed April 17; 1937 Fig. L

Inventor Delbert Newman, b H 4 3 Hi2 Attorney.

Patented Nov. 8, 1938 2,136,249 I :REFRIGERANT EVAPORATOR Schenectady, N. Y., assignor Delbert F. Newman,

to General Electric Company, a corporation of New York Application April 17, 1937, Serial No. 137,498

, V 5 Claims.

My invention relates to evaporators for refrigerating machines.

It is an object of my invention to provide an improved evaporator of the type comprising a freezing chamber having refrigerated side walls and. a shelf of relatively high heat absorbing capacity arranged between the walls for supporting freezing trays.

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 and forming a part of this specification.

For a better understanding of my invention, reference may be had to the accompanying drawing in which Fig. 1 is a front elevational view of a householdirefrigerator provided with an evaporator embodying my invention, and Fig. 2 is an enlarged perspective view of the evaporator shown in Fig.

Referring now to the drawing, in Fig. 1, I have shown a household refrigerator comprising a cabinet l having a door II and provided with a 25 removable top I 2 on which is mounted a refrigerating machine comprising a motor and compressor casing l3, a natural draft air cooled condenser I 4 and an evaporator l5. The evaporator I 5 comprises a U-shaped wall portion i6 30 defining a freezing chamber and a refrigerated shelf I! arranged within the freezing chamber. Duringthe operation of the refrigerating machine gaseous refrigerant is compressed by operation of the motor and compressor within the denser l4 where it is cooled and liquefied by the circulation of air over the condenser. The liquid refrigerant flows from the condenser through 'a connection l8 into a float valve chamber or receiver l9 and when a predetermined amount of liquid refrigerant has collected in the chamber IS a float arranged therein rises and allowsthe liquid refrigerant to pass through a connection into the wall'portion of the evaporator l5. Aportion of the liquid refrigerant is vaporized ,bylthe absorptionof heat from the air within the c abinet l0 and. liquid and gaseous refrigerant are discharged from the wall portion l6 into the shelf IT. The shelf I1 is provided with a header so" 2| formed in a'v'ertical portion thereof which is maintained about half full of liquid refrigerant,

so asto flood the passages extending from the header. The gaseous refrigerant collects in the header 2| above the level of liquid refrigerant 5 therein and is withdrawn therefrom through a conduit 22 and returned to the casing 13. The details of construction of theevaporator l5 are clearly shown in Fig. 2. The wall portion l6 which provides the side and bottom walls 0 of a freezing chamber is constructed of inner casing l3 and is discharged through the con-' and outer metal sheets 23 and 24 respectively. An extended series conduit 25 having relatively few turns is formed by providing an indentation in the outer sheet 24. The inner and outer sheets are out to the desired shape while fiat, the inner sheet being provided with end portions 26 extending beyond the ends of the outer sheet 24 so that they may be bentover the edges of the outer sheet as shown. The indentation 25 v is stamped in the outer sheet and the sheets are then secured together between the turns of the indentation and around the edges of the sheets by welding, brazing or in any other suitable manner, the end portions 26 being bent over the outer sheet24 and the sheets being thereafter bent into the 'U-shaped form of the wall portion l6. Flanges 21 at the tops of the side walls are provided in order that the evaporator may easily be secured to the removable top 12 of the cabinet lli. The shelf 81 comprises upper and lower metal sheets 28 and 29 respectively. The sheets 28 and 29 are cut to the desired shape while fiat,

the sheet 28 being provided with end portions 30 which may be bent around the ends of the sheet 29 as shown at the front of the shelf and with side pprtions 3i providing upwardly'extending fianges'for securing the shelf to the side walls of the. evaporator. At the rear of the shelf the header 2| is made of cylindrical form by providing complementary indentations in the sheets 28 and 29. The rear portion of the shelf indicated at 32, is bent vertically upwardly so that the header 2| is above the level of the shelf. The

lower sheet 29 is provided with a plurality of indentations forming U-shaped conduits 33 communicating at both ends with the header 2| below the level of liquid refrigerant therein, a manifold 34 and a plurality of ducts 35 providing communication between the manifold and theconduits 33. The shelf I1 is secured within the ,freezing chamber by welding, brazing or otherwise fastening the flanges 2| to the sides of the inner sheet 23 of the wall portion IS. The connection 20 is provided at one-end of theconduit 25 for admitting refrigerant thereto and a connection 36 is provided between the other end of the conduit 25 at one end of the manifold 34 so that refrigerant may be removed from the conduit 25 and admitted'to the manifold 34 from,

whence it is directed in jets from the ducts 35 into the passages 33 to produce acirculation of liquid refrigerant therei The wall portions I 6 are provided for cooling the air within the cabinet l0 and the conduit 25- is constructed with relatively few turns for containing refrigerantso that its heat absorbing capacity per unit area of wall surface will be'relatively low. The heat absorbing capacity per unit area of the shelf i1 is relatively'high since this shelf is provided with a-plurality of closely spaced 2 i 2,186,2dh

refrigerant circulating passages and since the liquid and gaseous refrigerant injected through the ducts 35 produces a rapid circulation of liquid refrigerant contained in the passages 33. The high heat absorbing capacity of the shelf insures quick freezing of water, desserts or the like placed in trays on the shelf.

During the operation of the refrigerating machine, liquid refrigerant ,is admitted to the evaporator l5 through the liquid line 20 and flows throughthe turns of the conduit 25 where some of the liquid is vaporized by the absorption of heat from the air surrounding the evaporator. The vaporized refrigerant and portions of liquid refrigerant are conveyed from the conduit 20 through connection 36 and flowinto the manifold 34. Liquid refrigerant is maintained in the'passages 33 of the shelf i1 and partially filling the header 2i and the liquid and gaseous refrigerant flowing from the manifold 34 through the ducts 35in jets produces a rapid circulation of the liquid refrigerant in the con-' duits 33. This provides a freezing shelf of high heat absorbing capacity since superheating of the liquid refrigerant and the accumulation of gaseous refrigerant within the passages 33 is prevented. The gaseous refrigerant collects inthe header 2| above the level of liquid refrigerant therein and is withdrawn and conveyed there fromthrough the suction line 2 2 by operation of the compressorwithin the casing l3.

From the foregoing it is evident that I have provided an evaporator of simple and rugged' construction having an air cooling portion and a freezing chamber within which is arranged a freezing shelf of high heat absorbing capacity.

While I have described my invention in connection with a household refrigerating machine, other applications will readily be apparent to those skilled in the art. I do not therefore desire my invention to be limited to the particular construction 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 refrigerant evaporator comprising sheet metal wall portions providing-a freezing chamher, a shelf arranged within said chamber, means including a conduit and a refrigerant header for containing refrigerant to cool said shelf, said conduit communicating at both ends with said header and said header being arranged to contain liquid refriferant to maintain said shelf conduit flooded with liquid refrigerant,

means for admitting refrigerant to said evaporator, means including an-extended c'onduit arranged in series between said shelf conduit and said refrigerant admitting means for conducting refrigerant over said wall portions, and means arranged between said extended conduit and said shelf conduit for directing refrigerant in a jet into said shelf conduit from said extended conduit to produce a circulation of liquid refrigerant within said shelf conduit, and means for convey ing gaseous refrigerant from said header.

2. A refrigerant evaporator comprising sheet metal portions providing side and bottom walls of a freezing chamber, a shelf arranged between said side walls within said chamber, means including an extended conduit for containing refrigerant to cool said side walls, means including a' plurality of conduits for containing refrigerant to cool said shelf, a header secured to said shelf and arranged in communication with said plurality of conduits, means for admitting refrigerant to said extended conduit, means providing communication between said extended conduit and said plurality of conduits for conveying refrigerant from said extended conduit and for directing refrigerant in jets into said plurality of conduits to produce a circulation of liquid refrigerant therein, and means for conveying gaseous refrigerant from said header.

3. A refrigerant evaporator comprising sheet metal portions providing the walls of a freezing chamber, a shelf arranged between said walls and having a vertical portion provided with a refrigerant header, a plurality of U-shaped conduits communicating with said header and arranged to contain refrigerant to cool said shelf, an extended conduit for containing refrigerant to cool said walls, means for admitting refrigerant to said extended conduit, means providing communication between said extended conduit and said U-shaped conduits for conveying refrigerant from said extended conduit and for directing refrigerant in jets into said U- shaped conduits to produce a circulation of liquid refrigerant therein, and means for conveying and a plurality of U-shaped conduits each communicating at both ends with said header for containing liquid refrigerant to cool said shelf, means for admitting refrigerant to said extended conduit, means -providing communication between said extended conduit and said U-shaped conduits for conveying refrigerant from said ex-' 4 tended conduit and for directing, refrigerant inf jets into said U-shaped conduits to produce a circulation of liquid refrigerant therein, and

means for conveying gaseous refrigerant from said header.

5. Aerefrigerant evaporator comprising sheet metal portions providing side and bottom walls of a freezing chamber, a sheet metal shelf arranged between said side walls and having a vertical portion extending upwardly from one end thereof, means including a header within said vertical portion and a plurality of U-shaped conduits formed within said shelf for containing liquid refrigerant to cool said shelf, means including an extended conduit having relatively few turns and formed within said walls for containing refrigerant to cool said walls, means for admitting refrigerant to said extended conduit, means including a manifold at the end of said shelf remote from said header and a plurality of ducts connecting said manifold and said U- shaped conduits for conveying refrigerant from said extended conduit and for directing refrigerant in jets into said U-shaped conduits to produce acirculation of liquid refrigerant therein, and means for conveying gaseous refrigerant from said header.

DELBERT F. NEWMAN.

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