US2079448A - Evaporator - Google Patents

Description

y 4, 1937. F. T. GROTHOUSE 2,079,443

EVAPORATOR Filed Nov. 3, 1934 Inventor:

Frank T Grothouse,

bkd l i Attor-neg- Patented May 4, 1937 UNITED STATES emails EVAPOBATOR Frank T. Grotliouse, Fort Wayne, Ind., assignor to General Electric Company, a corporation of New York Application November 3, 1934, Serial No. 751,337

18 Claims.

My invention relates to flooded type evaporators for refrigerating apparatus.

In refrigerating apparatus of various types an 1 evaporator is provided having an extended liquid refrigerant passage containing a portion which -is supplied with liquid vaporizable refrigerant from a compressor-condenser unit or other refrigerant liquefying apparatus. The liquid refrigerant supplied to the evaporator absorbs heat from various articles contained in a compartment in which the evaporator is located and is vaporized thereby. The refrigerant vaporized in the evaporator passes to a header in which the liquid and vaporized refrigerant are separated, the latter being returned to the refrigerant liquefying apparatus. The liquid refrigerant is preferably supplied to the evaporator remote from the header in order to induce circulation of refrigerant through the evaporator. Evaporators of the type described may advantageously be made of complementary sheet metal portions at least one of which has indentations therein forming the passage and header described. Such a construction is economical to manufacture, but

care must be exercised in its design and manufacture in order that the danger of separation of the sheet metal portions due to internal pressures caused by the vaporized refrigerant may be avoided, while at the same time an eflicient cir- 31) culatory system must be had.

It is an object of my invention to provide a sheet metal evaporator of the type described, which will be rugged and structurally strong in order to resist the internal pressures therein, and

35 which can be economically manufactured of thin sheet metal.

It is a further object of my invention to provide an evaporator of the type described in which provision is made for injecting liquid refrigerant therein at a plurality of points remote fromthe header without the necessity of providing pipes or other obstructions on the exterior walls of the evaporator.

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 re ference may be had to the accompanying drawing in which Fig. 1 is a front elevation of a portion of a refrigerator cabinet having my improved evaporator arranged therein and provided with a refrigerating system connected to the evaporator for cooling the cabinet; Fig. 2 is a perspective view of my improved evaporator, and Fig. 3 is a sectional front elevation of the evaporator shown in Fig. 2.

Referring to the drawing, in Fig. 1, I have V Cr shown a refrigerating system including an evaporator embodying my invention. In this system the motor and compressor are arranged in a hermetically sealed casing l0. Gaseous refrigerant is compressed by the motor driven compressor in casing ill and is discharged into a condenser where it is liquefied. The liquefied refrigerant flows from the condenser through a flow controlling float valve l2 into a liquid line l3, which injects liquid refrigerant into the lower portion of an evaporator l4 located in the food storage compartment of a refrigerator cabinet I la.

In accordance with my invention the evaporator M comprises complementary sheets of metal or portions thereof, i5 and IS. The exterior sheet i5 is provided with a pair of transverse indentations I1 and I8 near the upper edges thereof, which cooperate with the complementary indentations l9 and 20 in the sheet iii to form elongated cylindrical headefs 2| and 22. The exterior sheet I!) is also provided with a transverse indentation 23 forming a manifold at the bottom of the evaporator l4 which is connected to an upper manifold formed by indentation 24 through a 'set or series of parallel refrigerant circulatory passages formed by indentations 25. The adjacent ends of the header 2| and the manifold 24 are connected by passages formed by indentations 26 and 21. Manifolds 28 and 29, connected by refrigerant passages are similarly arranged on the opposite side of the evaporator. The adjacent ends of manifold 29 and header 22 are connected by passages corresponding to passages 26 and 21 on the opposite side of the evaporator. The sheets 5 and it are joined together by welding them along their peripheral edges and between the indentations formed therein by line welding or a series of closely spaced spot welds. It should be particularly noted that the sheets l5 and I6 are welded together in substantially continuous lines along the longitudinal edges of the headers 2| and 22 by such line welds or a series of spot welds. In this way the headers are given great structural strength in order to prevent separation of the sheets l5 and |6 due to the pressure of the vaporized refrigerant contained in the headers 2| and 22 during the operation of the evaporator. Furthermore, this construction makes it possible to obtain sufficient strength when the evaporator is made of relatively thin sheet metal. After the sheets l5 and I6 have been joined together as described, they are bent to a U-shape, and the headers 21 and 22 are connected by an equalizer pipe 3|, having its axis substantially at the level of liquid refrigerant in the headers.

In the operation of the evaporator described, liquid refrigerant is supplied thereto through the liquid line l3 which enters the evaporator l4 through the side wall of the header 2|, passes I3. It should be noted that the branched ends 33 and 34 of liquid line |3 are of the same developed length so that there will be an equal pressure drop in each branch and hence an equal distribution of refrigerant in the circulatory systems on each side of the evaporator. The liquid refrigerant so injected passes along the manifolds 23 and 28, upwardly through some of the parallel refrigerant passages and located near the rear of the evaporator, these passages being connected at their upper ends by the manifolds 24 and 29, respectively. The liquid refrigerant passing upwardly through the refrigerant passages 25 and 30 is partially vaporized therein by the absorption of heat from articles contained in the compartment Ma and in the freezing compartment formed by the evaporator I4, and circulates upwardly to the headers 2| and 22 through the passage 26 and the corresponding passage on the other side of the evaporator where the liquid and vaporized refrigerant are separated, the

headers being maintained about half full of liquid refrigerant. The headers thus contain liquid refrigerant and constitute chambers for the accumulation of vaporized refrigerant above the level of the liquid refrigerant therein. The liquid refrigerant remaining in the headers 2| and 22 is recirculated downwardly through the passage 21 and the corresponding passage on the other side of the evaporator to the manifolds 24 and 29 from which it passes downwardly through the part of the passages 25 and 30 in the front of the evaporator, and is entrained by the fresh liquid refrigerant injected into the bottom manifolds 23 and 28. It will be noted that the equalizer pipe 3| is connected to the headers 2| and 22 at about the center of the normal liquid level therein so as to facilitate the free circulation of vaporized and liquid refrigerant between the headers. The vaporized refrigerant is drawn off to the motor driven compressor in the casing l0 through a suction line 35 connected to the header 2|. It is advantageous to locate the liquid line |3 within the evaporator |4 rather than beside it since unobstructed, easily cleaned walls are thus provided, also the assembly operations are simplified since the connections for conduits l3 and 35 are side by side and may be soldered or otherwise secured at the same time.

The evaporator I4 is provided 'with a refrigerated shelf made up of complementary sheets 36 and 31 on which articles to be frozen may be conveniently supported as well as on the lower portion of the evaporator, thus increasing the storage capacity of the freezing compartment formed by the evaporator. The shelf is supported by ears 36a formed on the edge of sheet 36 and welded or otherwise secured to the sheet I6 of the main portion of the evaporator. A pair of longitudinal U-shaped refrigerant passages 38 and 39 are formed in the shelf by indentations in the sheet 31, the ends of the U-shaped passages being connected by' a cross manifold 40 which is also formed by an indentation in sheet 31. It is desirable to provide some arrangement for producing a circulation of refrigerant from the side walls through the passages in the shelf. In the evaporator illustrated liquid refrigerant is supplied to the base of the U-shaped passage 39 in the shelf by conduit 4| communicating with one of the refrigerant passages 25 below the passage 39 and after circulating through the legs of the refrigerant passage 39 in the shelf it passes through the manifold 40 to the U-shaped passage 38 and after circulating through the same is re turned to one of the refrigerant passages 30 through a conduit 42 communicating therewith above the U-shaped passage-38. It should be noted that the conduits 4| and 42 are connected to the refrigerant passages 25 and 30 respective- 1y,,through holes formed in the sheet I5 which forms the exterior walls of the latter. In this way smooth inner walls are provided for the evaporatorwhich may be easily cleanedand freed of frost and ice upon the defrosting of the evaporator. Also the manufacture of the evaporator is simplified in this manner since most of the preforming operations necessary for the sheets l5 and I6 may be concentrated in the exterior sheet l5.

The upper edges of the sheets I5 and I6 are bent to form outwardly extending flanges 43 -and 44 respectively. These flanges are provided with holes 45 through which fastening devices may be inserted for securing the evaporator M to the top of the cabinet |4a.

While I have shown a particular embodiment of my invention in connection with an evaporator of a compression refrigerating machine, I do not 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 m invention.

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

1. An evaporator of the flooded type for refrigerating apparatus including complementary sheet metal portions, at least one of said sheet metal portions having an indentation therein forming an elongated header for said evaporator, said header being adapted to contain liquid refrigerant and constituting a chamber for the accumulation of vaporized refrigerant above the level of liquid refrigerant therein, means joining said sheet metal portions in substantially continuous lines along the longitudinal edges of said indentation for structurally strengthening said header, means including an extended refrigerant passage formed between said sheet metal portions and communicating with said header adjacent the opposite ends thereof below the level of liquid refrigerant therein for providing a reentrant refrigerant circulatory path through said header, and means for withdrawing vaporized refrigerant from said header.

2. An evaporator of the flooded type for refrigerating apparatus including complementary sheet metal portions, at least one of said sheet metal portions having an indentation therein forming an elongated header portion for said evaporator, said header being adapted to contain liquid refrigerant and constituting a chamber for the accumulation of vaporized refrigerant above the level of liquid refrigerant therein, said sheets being welded together in substantially continuous lines along the longitudinal edges of said indentation for structurally strengthening said header, means, including an extended refrigerant passage formed between said sheet metal portions and communicating with said header adjacent the opposite ends thereof below the level of liquid refrigerant therein for providing a reentrant refrigerant circulatory path through said header, and means for withdrawing vaporized refrigerant from said header.

I sheet metal portions and depending from said manifold on the side of said manifold remote from said header and communicating with said manifold, said sheet metal portions being welded together in substantially continuous lines along the longitudinal edges of said header for structurally strengthening said header.

4. An evaporator of the flooded type for refrigerating apparatus including complementary sheet metal portions, at least one of said sheet metal portions having an indentation therein forming an elongated transverse header portion, a manifold formed between said sheet metal portions parallel to said header, means including passages providing communication between the corresponding ends of said header and said manifold for providing a reentrant refrigerant circulatory path through said header, and means including an extended refrigerant passage formed between said sheet metal portions and depending from said manifold on the side of said manifold remote from said header and communicating with said manifold at a plurality of points for providing a reentrant refrigerant circulatory path through said manifold, said sheet metal portions being welded together in substantially continuous lines along the longitudinal edges of said header for structurally strengthening the same.

5. An evaporator of the flooded type for refrigerating apparatus including complementary sheet metal portions, means for joining said sheet metal portions together, at least one of said sheet metal portions having an indentation therein forming a transverse header portion, a pair of manifolds formed between said sheet metal portions parallel to said header on one side thereof and communicating with the same at the opposite ends thereof to form a refrigerant circulatory path through said header, and a plurality of refrigerant circulatory passages extending between said manifolds.

6. An evaporator of the flooded type for refrigerating apparatus including complementary sheet metal portions having a horizontal part and an upstanding part, means for joining said sheet metal portions together, at least one of said sheet metal portions having an indentation therein forming a transverse header portion, and a manifold below said header portion and in the upper part of said upstanding part, said manifold and said header communicating at their opposite ends to form a reentrant refrigerant circulatory path through said header, and a refrigerant passage extending from said manifold between said sheet metal portions in said horizontal part thereof and in the lower part of said upstanding part thereof, said manifold and said passage being formed by indentations in at least one of said sheet metal portions.

7. An evaporator of the flooded type for refrigerating apparatus including complementary sheet metal portions having a horizontal section and an upstanding section, means for joining said sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a transverse header portion and a manifold below the same in the upper part of said upstanding section, and a second manifold in said horizontal section formed between said sheet metal portions, said manifolds and said header communicating at their corresponding ends to form a reentrant refrigerant circulatory path through said header, and a plurality of refrigerant circulatory passages extending between said manifolds and formed between said sheet metal portions.

8. An evaporator of the flooded type for refrigerating apparatus including complementary U-shaped sheet metal portions forming a plurality of walls of a freezing chamber, means for joining said sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a header portion adjacent the top of each leg of said evaporator, a manifold below each of said headers formed between said sheet metal portions, each of said manifolds communicating with the adjacent header at the ends thereof to form a reentrant refrigerant circulatory path through said header, and a refrigerant passage formed between said sheet metal portions and extending downwardly from each of said manifolds.

9. An evaporator of the flooded type for refrigerating apparatus including complementary U-shaped sheet metal portions forming a plurality of walls of a freezing chamber, means for joining said sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a header portion adjacent the top of each leg of said evaporator, a manifold below each of said headers formed between said sheet metal portions, each of said manifolds communicating with the adjacent header at the ends thereof to form a reentrant refrigerant circulatory path through said adjacent header, a set of refrigerant passages formed between said sheet metal portions extending downwardly from each of said manifolds and a separate manifold connecting the lower ends of each of said sets of refrigerant passages respectively.

10. An evaporator of the flooded type for refrigerating apparatus including complementary U-shaped sheet metal portions forming a plurality of walls of a freezing chamber, means for joining said sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a header portion in each leg of said evaporator adjacent the top thereof, a manifold below each of said headers. formed between said sheet metal portions, each of said manifolds communicating with the adjacent header at the ends thereof to form a reentrant refrigerant circulatory path through said adjacent header, a set of refrigerant circulatory passages formed between said sheet metal portions and extending downwardly from each of said manifolds, a separate manifold connecting the lower end of each of said sets of refrigerant passages, respectively, and a refrigerant supply conduit entering said evaporator through the Wall of one of said headers passing downwardly through a side wall of said evaporator between said sheet metal portions and having a branched outlet discharging into said last mentioned manifolds in the lower part of said evaporator.

11. An evaporator of the flooded type for refrigerating apparatus including complementary U-shaped sheet metal portions forming a plurality of walls of a freezing chamber, means for joining said sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a header portion in each leg of said evaporator adjacent the top thereof, a separate refrigerant circulatory passage formed between said sheet metal portions for each side of said evaporator and communieating with the adjacent header, and a refrigerant supply conduit entering said evaporator near the top thereof passing downwardly through a side wall of said evaporator between said sheet metal portions and having a branched outlet discharging into the lower portion of each of said refrigerant passages.

12. An evaporator of the flooded type for refrigerating apparatus including complementary U-shaped sheet metal portions forming a plurality of walls of a freezing chamber, means for joining said sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a. header portion in each leg of said evaporator adjacent the top thereof, a pair of manifolds in the bottom of said evaporator formed between said sheet metal portions, a plurality of refrigerant circulatory passages formed between said sheet metal portions and extending between said manifolds and the headers on the same side of the evaporator, respectively, and a refrigerant supply conduit entering said evaporator near the top thereof, passing downwardly through a side wall of said evaporator between said sheet metal portions and having a branched outlet discharging into said manifolds in the lower part of said evaporator.

13. An evaporator of the flooded type for refrigerating apparatus including complementary U-shaped sheet metal portions forming a plurality of walls of a freezing chamber, means for joining said sheet metal portions together, indentations in at least one of said sheet metal portions forming refrigerant circulatory passages in the side walls of said evaporator, a shelf extending between said side walls of said evaporator, a refrigerant passage formed in said shelf and inlet and outlet connections for said refrigerant passage for said shelf including a. pair of conduits communicating with an adjacent portion of said refrigerant passages formed in. said side walls of said evaporator on the exterior side thereof and with said refrigerant passage for said shelf, said inlet and outlet connections being respectively below and above said passage in said shelf.

14. An evaporator of the flooded type for refrigerating apparatus comprising a plurality of refrigerant circulatory passages forming a plurality of walls of a freezing compartment, a shelf extending across said compartment and a refrigerant passage formed in said shelf including a transverse-manifold, a plurality of U-shaped refrigerant passages communicating at each of their ends with said manifold, an inlet connection connected to one of said U-shaped passages at a point remote from said manifold and an outlet connection connected to another of said U- shaped passages at a point remote from said manifold.

15. An evaporator of the flooded type for refrigerating apparatus comprising a plurality of refrigerant circulatory passages forming a plurality of walls of a freezing compartment, a shelf extending across said compartment, said shelf including complementary sheet metal portions,

means securing said. sheet metal portions to-' gather, at least one of said sheet metal portions having indentations therein forming a transverse manifold and a plurality of U-shaped refrigerant passages communicating at each of their ends with said manifold, an inlet connection connected to one of said U-shaped passages at a point remote from said manifold and an outlet connection connected to another of said U-shaped passages at a point remote from said manifold.

16. An evaporator of the flooded type for refrigerating apparatus including complementary sheet metal portions forming a freezing chamber, at least one of said sheet metal portions having indentations therein forming two headersand a. plurality of refrigerant circulating passages, each of said headers having a plurality of said passages in communication therewith, means for circulating refrigerant upwardly in one of said passages and into one of said headers, means including a shelf arranged in said chamber for supporting freezing trays therein, said shelf having a refrigerant passage, and means providing communication between said shelf passage and said refrigerant circulating passages for producing a circulation of refrigerant from said one of said passages through said shelf passage and into another of said refrigerant circulating passages to cool said shelf. I

17. An evaporator of the flooded type for refrigerating apparatus including complementary sheet metal portions forming a freezing chamber, at least one of said sheet metal portions having indentations therein forming a header and two sets of refrigerant circulating passages, means including said header for providing communication between the upper ends of said sets of passages, means including a shelf arranged in said chamber for supporting freezing trays therein, means including a passage arranged in said shelf and providing communication with one of the passages in one of said sets of passages and one of the passages in the other of said sets of passages for conveying refrigerant from said one of said sets of passages to said other set and for producing a circulation of refrigerant in said shelf to cool said shelf.

18. An evaporator of the flooded type for refrigerating apparatus, including complementary U-shaped sheet metal portions forming a plu-,

rality of walls of a freezing chamber, means for joining said sheet metal portions together, at least one of said sheet metal portions having indentations therein forming a header portion adjacent the top of one leg of said evaporator, means including two sets of passages formed between said sheet metal portions for cooling said walls, means including said header for providing communication between the upper ends of said sets of passages, a shelf extending between said

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