US2360739A - Spiral plate heat exchange structure - Google Patents

Description

Oct. 17, 1944. s s d SPIRAL- PLATE HEAT EXCHANGE STRUCTURE Filed May 26, 1945 .W 21 Z 4 W 6 m A l/ 3 4 M 2 IN ENTOR fig ATTORIBZ Patented Oct. 17, 1944' orr cs SPIRAL PLATE HEAT EXCHAN G STRUCTURE Sven Giista Striim, Ulvsunda, Sweden, assignor to American Heat Reclaiming Corporation,

New York. N. Y.

Application May 26, 1943, Serial No. 488,563-

In Sweden November 1, 1940 3 Claims.

The present invention relates to spiral plate heat exchange structure of the kind comprising two walls which are spirally wound with substantially parallel surfaces in radially spaced relationship so as to form between them two separate spiral channels, and more particularly to such apparatus having means for permanently closing said channels .alternately at opposite facial sides while the other facial side remains open, and removable cover plates provided at each end for sealing the open facial sides of the channels.

The heat exchanger referred .to is in actual modern practice so constructed that the plate walls are in alignment at face ends, and the means for permanently closing the channels in the fashion stated consist of striplike spiral closure members inserted between marginal wall portions of the channel sides which are to be closed, and tightly united with each of the adjacent wall edges, whereas the cover plates rest upon the edges of .both the plate walls.

With this construction it is somewhat difficult to obtain satisfactory sealing of the open channel sides by the cover plates inasmuch as the welded joints between the spiral closure members and the wall edges present rather uneven facial surfaces to the cover plates so that no tight engagement is possible, and to secure perfect contact the face ends of such spiral plate structure must be machined with great accuracy which requires much costly labour.

It is an object of the present invention to provide a structure of the kind referred to in which each cover plate rests only upon one of the spiral walls so that onl one of the wall edges at each end has to be machined to form a sealing surface for the attached cover plate, thereby decreasing the manufacturing costs.

Another object of the invention is to provide a structure of the kind referred to which has no joints at the facial wall edges in contact with the cover plates, whereby the required machining of those wall edges will be much easier than in the prior structures.

Further objects and aspects of the invention 'will be apparent from the following specifica- According to the invention the objects mentioned are realized by forming the structure with the spiral walls axially displaced with respect to each other so that each outflanks the other at opposite ends, by virtue of which the cover plates rest solely. upon the outermost wall edge at the respective adjacent end.

One preferred em g l ent of ,the invention consists in securing the striplike spiral members for permanently closing'the channels with each of the adjacent wall surfaces in suchv a manner that the joint with the outermost extending spiral wall will be situated some'distance' inwardly from theedgeofthatwall. 1 i .l .l

Further objects andadvantages of'niy'invention will be apparent from the, following description', co njsider'ed in c'onnectionwith the. accompanying drawing, whichjforms a part of this specification, and ofwhichi'. H

Fig. 1 is a cross-sectional view,'taken on the line I-l of Fig. 2, of a heat exchanger in accordance withmyinvention;

Fig. 2 is a cross-sectional view taken on the line 22 ofFig. 1;

Fig. 3 is a cross-sectional view of the central portion of the heat exchanger, and is taken on the line 33 of Fig. 2; and

Fig. 4 is a cross-sectional view of a portion of a heat exchanger in accordance with my invention embodying a modified form of spiral closure member.

The heat exchange structure shown in Figs. 1 through 3 inclusive includes two plate walls I and 2 which are spirally wound with parallel surfaces in radially spaced relationship so as to form between them two spiral channels 3 and 4. One channel is open at one side and the other channel is open at the opposite side, and near these open sides of the channels the walls of the same are stayed by small distance pieces 5, for instance,

which are positioned between the walls, whereas the opposite facial side of each channel is permanently closed by means, of a striplike spiral member 6 which is inserted between marginal portions of the walls and united with each of them by welding so that the channels are closed alternately at opposite sides. As called for by the invention, the plate walls I and 2 which conveniently have about the same width, are somewhat displaced axially with respect to each other so that at each side one of the plate walls projects beyond the other. For sealing the open sides of the channels there is provided a removable cover plate or the like at each side, which is attached by means of bolts to a flange which is welded to the spiral plate structure as shown. In this case only the axially outermost extending edges of the plate walls engage the cover plates 50 that each of the same rests solely upon one of the walls and it is obvious that the open 1 sides of the channels are sealed in such a manner that communication-between the individual channels in the radial direction outside of the wall edges is prevented. Thus, the spiral channels are kept closed during operation but may be made accessible for cleaning bytaking oil the cover plates, inside. of which there may be placed suitable elastic sealing material in order to ensure perfect tightness.

As shown in the drawing and mentioned above the welded Joint between the spiral members 6 and the axially outermost extending wall portions should preferably be situated at some distance in from the wall edges, while the weld of the spiral members to the axially inner wall portions may be effected either close to the edges of the same or inwardly therefrom, as shown at the upper and lower sides in Fig. 1, respectively.

According to Fig. 4 the spiral members Safor permanently closing the channels are L-shaped in cross section with an outwardly directed flange parallel to the axially inner wall I and with the radial portion of the member 6a normal to the axially outer wall 2, the joints being united preferably by fusion welding.

The heat exchanger described is provided with connections for supply or discharge of the heat exchanging fluids at the centraland peripherical ends; of the spiral channels so that theiluids 1 are caused to pass ou h-the channels-in the" spiral direction, generally in counter current} flow. Zin the drawing 'the peripherical connections referred to and provided for the channels 3 and 4 are designated 3a and la, respectively, while the central connection 31) and 4b of the channels 3 and 6 are shown as openings in the cover plates 1 and la, respectively.

Finally, it should be understood that the invention covers any further desirable modification which maybe made without deviating from its scope as expresed by the appended claims. "Thus, what I claim and desire to secure by Letters Patent is:

1. A spiral plate heat exchange structure, comprising two spiral walls having substantially parallel surfaces in radially spaced relationship to thereby form between them two separate spiral 5 channels, said spiral walls being axially displaced with respect to each other so that each extends axially beyond the other at opposite side edges, means for permanently closing one of said channels at one side and for closing the other chan- 10 nel at the opposite side, said means being spaced inwardly from the edge o'f'the wall which extends axially beyond the other wall, and a'removable cover plate provided at each side for 'sealing'the.

surfaces in such a manner that the joint with the axially further extending spiral wall is spaced axially from the adjacent edgeof the last mentioned wall.-.

3. A; -spiral5-plate :heat exchange. structure as 7 set forth in--claini;il;- in which said means for permanentl .closingthe channels consists of haped. .in cross-section inserted betweenwmarg a1 wan portions of the'channel side whichj are tolbe closed, each of said strips having an outwardly. extending axial flange welded parallel to -the wall which extends the lesser distance in axial direction, and having a radial portion welded normal to the wall which :extends the greater distance in axial direction, whereby the last-mentioned weld is spaced inwardly from the adjacent edge of the last-men- 40 tioned wail.

SVEN GGSTA s'rRCiM.

- U I Certificate'of Correction Patent No. 2,360,739. October 17, 1944.

' SVEN GOSTA STROM It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, second column, line 25, claim 2, after axially insert inwardly; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 17th day of September, A. D. 1946.

LESLIE FRAZER;

First Assistant Commissioner of Patents.

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