US2591109A - Refrigerant evaporator - Google Patents

Description

April 1, 1952 J. o. WADE REFRIGERANT EVAPORATOR 2 SI-IEETS--SHEET 2 Filled July l5, 1948 VM dw Patented Apr. 1, 19452 UNITED STATE-s-` PATENT OFFICE N .i

REFRIGERANT EVAPORATOR James O. Wade, Adrian, Mich., assignor to Bohn Aluminum & Brass Corporation, Detroit, Mich., a corporation of Michigan Application July 15, 194s, serial No. 38,770

2 claims. (c1. 62-1261 This invention relates to an improved evapv orator for a refrigerating unit.

The invention relates to the type of evaporator in which metal tubes are brazed to a metal sheet. as for example in the patent to McCullough etal. 2,359,926, According to the present invention a plurality of tubes and a plurality of headers are brazed to a metal sheet with their interiors interconnected to form a fluid-tight assembly with inlet andoutlet openings.

A particular feature of the invention resides in the fact that the accumulating header is inserted in a slot formed in the sheet, this arrangement providing for a neat and rigid mounting of the accumulating header.

An additional feature of the invention resides in the fact that the distributing header is formed from a piece of tubing which has its ends co1- lapsed, a fluid-tight joint at the collapsed ends being produced by causing brazing compound to run between the meeting walls of the tube at the same time the parts are brazed to. the sheet.

Other objects and advantages of the invention will become apparent as the description proceeds.

Although preferred forms of the invention are disclosed herein for the purpose of illustration, it should be understood that various changes may be made without departing` from the spirit of the invention as herein set forth and claimed.

In the drawings:

Fig. 1 is a perspective view of the bottom and the accumulator end of an evaporator which incorporates the invention.

Fig. 2 is a perspective View of the device of Fig. l but showing the top and opposite end.

Fig. 3 is a perspective partly in phantom showing a modified structure.

Fig. 4 is a fragmentary sectional View of part of the structure of Fig. 3.

Fig. 5 is a fragmentary section taken on the line 5--5 of Fig. 3.

Figure 6 is a fragmentary sectional view of part of the distributing header.

Referring to the drawings in greater detail, Figs. 1 and 2 illustrate an evaporator in which a series tube I0, a distributing header II, parallel tubes I2 andan accumulating header I3 are all brazed to a sheet I4.

In the particular example illustrated in Figs. l and 2 the series tube I0 is bent sinuously so as to cover the top of the evaporator, then passes around a corner and is bent sinuously so as to cover one side of the evaporator and part of the bottom. The series tube then discharges into the distributing header II which is located at about the middle of the bottom wall of the evaporator. `A plurality of parallel tubes I2 extend from the distributing header across the bottom wall of the evaporator and upa side wall to discharge into the accumulating header I3. It will be understood that liquid refrigerant is supplied at the inlet end I5 o the tube I0, and that gaseous refrigerant is withdrawn from the return line I 5 connected to the accumulating header.

The invention is not conned to the use of any particular material buta preferred material is commercially pure aluminum for all of theV parts previously described. Preferably the sheet I4 is a sheet of commercially pure aluminum clad on one side with a coating of a brazing alloy formed I of aluminum with a small percentage of silicon, for example 5% of silicon. This aluminum-silicon alloy has a melting point somewhat lower than that of the commercially pure aluminum. As used herein the term aluminum material includes aluminum alloys as well as commercially pure aluminum.

In manufacturing the evaporator the sheet I4 is originally in at condition. The various tubes and headers are formed as shown in the drawings and placed on the clad side of flat sheet I4. The assembly is then passed through a brazing furnace and raised to a temperature at which the brazing alloy melts and brazes all of the parts into a single, unitary aluminum structure. After the brazing operation the sheet I 4 is bent up into its final shape.

As clearly shown in Figs. l and 6 the distributing header II is formed from a piece of tubing slightly larger in diameter than the tubes I0 and I2. The opposite ends of header II are closed by attening down the tubing until its inside walls meet and making a saw cut Il through the upper wall of the tubing at the flattened portion. An extra amount of brazing material may be inserted in the saw cut Il to insure a iluid-tight seal of these end joints as the result of the brazing opera-tion.

As shown in Fig. 4 the end of tube I0 is reduced in size, i. e., tapered down, inserted in a hole of corresponding size formed in the wall of header I I, and brazed in place.

The parallel tubes I2 are connected to header I I in a, similar manner but their ends are reduced to a smaller diameter than the end of tube I0.

IThe outlet ends of the parallel tubes l2 are secured into openings formed in the wall of accumulating header I 3.

In order to permit the tubes I 2 to fit nat against the sheet I 4 throughout their length, and to provide a, rm and neat mounting, the accumulating header I3 ts snugly into a slot of corresponding shape cut entirely through sheet Il. If desired an additional amount of brazing material may be supplied around the header I3 in order to provide a strong joint. The ends of header I3 are closed by cup-shaped disks in a Well-known manner. The return line I6 is secured to the header I3 in'. a mannery similar to theatubev |21` asrillustrated: in Fig. 4;

It will be understood that all of the parts are formed in the manner previously described, assembled in their respective positonsranany.- necessary additional brazing materialv is putin place before the assembly is 1passed"tlirouglif tliefl5 brazing oven.

It should be understood that the invention canv be adapted to a wide variety of evap'cnators.'I The" example of Figs. 3 and 5 illustrates a form in which the series tube I0 first passes acrossi'the".y

underside of a shelf I8, then passes through the A side-iwallof the evaporator andcontinues overltheff."

outsideofthe: evaporator in the :manner previl ously described. In constructing Ajan i evaporator? as'shown in Fig. 3 the lshelfswitli:itszattacledi'y a plurality of tubes communicating with the header, each of the tubes being secured to the sheet throughout itslength, the metal sheet having an elongated slot cut therethrough, the suction header tting closely into said slot and being secured to the sides of the slot.

2. An evaporator for a refrigeration system Whichvcomprises a sheet of metal, a refrigerantcarrying?. tube in contact' with the`metal sheet to cool'the'metal sheet, a hollow, elongated, cylindrical header member of larger diameter than the refrigerant-carrying tube and in communication withzthef refrigerant-carrying tube, the metal sheethaving an elongated slot cut therethrough, thecylindrical header member fitting closely into saidlslotandbeing' secured to the sides of the slot;

JAMES O. WADE.

REFERENCES CITED The following references are of record in the 'le of this patent:

UNITED STATES PATENTS Number Name Date 1,684,083-y Bloom Sept. ll, 1928;" 1,903,351" Lipman: Apri 4, 1933'l 210091,910 Toubor'g July 30,` 19352l 2,091,584" Brown Aug.' 31, 1937` 2,117,861V Steenstrup vMay 17, `1933.-"`

2,154,874 Smith A`pr..18, 1939i: 2,2'3Y7j5`00v Peltier Apr.l 8;'19211 2,239,178E ConradyV Apr; ,221.11941i 2,291,363* Atchison' J illy 28;` `1942 2,306,772'Ll Benson Dec. 29, 19425..

Furry Oct. 16, 1945"-v

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