US2429508A - Plate heat exchange apparatus - Google Patents

Description

Qct. 2l', 1947. 1J. F. BELAIEFF 2,429,508

\ PLATE HEAT EXCHANGE APPARATUS Filed Feb 3, 1944 VVI E 4 AYAYAVAVImnvAvAwE? Patented Oct. 21, 1947 PLATE HEAT EXCHANGE APPARATUS James Frank Belaei, Cricklewood, London, England, assignor of two-thirds to Cyril Terence Delaney and Gallay Limited, a company of Great Britain, both of Crieklewood, London,

England Application February 3, 1944, Serial No. 520,865 In Great Britain February 5, 1943 2 Claims. 1

Thisinvention relates to plate heat exchange apparatus and more particularly to heat exchange apparatus of the kind known as secondary heat exchange apparatus.

Radiators, oil coolers or other heat exchangers for use in the cooling system of internal combustion engines of aircraft, motor vehicles or stationary plant are very often required to be of other than rectangular shape. The medium to be used as a coolant in the radiator or the like is hereinafter referred to as the cooling medium. The medium to be cooled in the radiator or the like may, and usually is, itself a coolant in the engine or elsewhere, and is hereinafter referred to as the coolant. In the radiator of annular shape it may be constructed so that the air or other cooling medium will enter at the centre of the annulus and leave the unit at the periphery. Since the passages for the coolant must be kept small, such an arrangement necessitates a heat exchange unit having an entry area for the cooling medium which is smaller than the exit area. Consequently, in such construction the passages for the cooling medium have to expand progressively from the inner to the outer periphery of the heat exchange unit. These passages for the cooling medium are of course, constituted by the adjacent walls of the passages for the coolant with or without the interposition of intermediate walls, and the passages for the coolant are supported in spaced relation for example, by means of thin corrugated strips, the corrugations being V-shaped.

Where the distance between the adjacent walls is constant the thin corrugated strips can easily be used and give excellent support whilst serving at the same time as cooling surfaces. When, however, the distance between the adjacent walls is not constant the depth of the corrugations has to vary. One way of varying the depth of the corrugations is to use an arcuate strip but this presents certain difficulties such as the limitation of the length of strip by reason of its arcuate form. Another method would be to subject the strip to a stretching operation in a press instead of a simple corrugation process. This, however, is not too good for two reasons, namely, that the strip is already very thin and, therefore, likely to fracture if further stretched, and also that the strip would be thinned out just where it should conduct most heat if it is to operate with the maximum possible efficiency.

Other orthodox forms of secondary surface radiators comprise perforated fins fitted on tubes. The construction of annular radiators by this 2 means would be most difficult and wasteful owing to the fact that the development of the fins will not be rectangular or inthe shape of a parallelogram but will take the form of an annulus or section of an annulus.

The object of the present invention is to provide a new construction which will overcome some or all of the above difficulties.

According to the present invention, a plate heat exchange apparatus having diverging and/or converging adjacent walls held in spaced relation by corrugated elements is characterized in that the cross-sectional form of said corrugations is varied longitudinally thereof to co-operate with the adjacent walls without changing the lineal dimensions of the material from which such elements are formed. -The lineal dimensions of all such cross-sections are equal so that corrugated elements of varying depth of corrugation maybe produced from a straight strip.

In order that the invention may be more fully understood one form of plate heat exchange ap. paratus will now be described with reference to the drawings led herewith, wherein- Fig. 1 is a perspective view of a portion of an annular radiator made in accordance with the present invention; and

Fig. 2 is a perspective view rugated strips used in the construction of the radiator shown in Fig. 1.

The annular or cylindrical form of heat exchange unit shown comprises a plurality of chambers I for the coolant, each chamberconsisting of a pair of parallel thin walls 2 held in spaced relation by a thin corrugated strip 3 the corrugations of which run parallel to the axis of the annulus or cylinder. It is, of course, understood that the inner and outer edges of the chambers I are sealed, and the ends are sealed into header tanks which have been omitted for the sake of clearness as they form no part of the present invention. The chambers I are arranged radially around the axis of the cylinder. Disposed medially between each of the chambers I is an intermediate wall 4 and disposed between the intermediate walls 4 and the walls 2 of the chambers I are the corrugated elements 5 which form the subject of the present invention and the construction of which will be described more fully with particular reference to Fig. 2 in which a part of one of the elements is shown on an enlarged scale. v

It will be observed that at one edge the corrugatiQnS @le V-shaped Whilst at the other edge the of one of the cor- 3 corrugations are of three-sided right-angled channel formation.

The strip 5 is shaped in such a manner that the pitch p' of the V-shaped corrugations, and the pitchp of the three-sided right-angle channel formation corrugations are identical, and the length of the contour of the strip edge in pitch p, that is, :cto e', is identical to the length of the contour of the strip edge in pitch p', that is, x' to e', and the length of the cross-sectional contour of the strip in the pitch of a corrugation at all positions between the two edges of thestrip is identical to the length of the contour at each edge of the strip in the pitch of a-corrugation.

In other words the tops of the corrugations are flattened progressively starting at one edge and reaching a maximum at the other edge. It will also be observed that the pitch of the corrugations remains unchanged and is constant for any cross section. The cross-section of the sheet at any position between the edges is of three-sided channel section having a at base and diverging sides. The element is `stamped from a straight strip without any stretching whatsoever so that if all the folds are ironed out it will return to a straight strip, but owing to the change in the shape of the corrugations from edge to edge the depth of the corrugations is increased progressively from the edge having the three-sided right- 1. In a plate heat exchange apparatus hav-luv diverging adjacent walls held in spaced rclatm:l by corrugated elements, a corrugated clement formed of strip metal in which the depth of each corrugtion increases progressively from on@ end of said corrugation to the other, the pitch of cach corrugation and the length of the cross-sectional contour in the pitch of a corrugation remaining constant throughout the length of the corrugation, the sectional form of the corrugation varying longitudinally thereof.

2. In a plate heat exchange apparatus having diverging adjacent walls held in spaced relation by corrugated elements, a corrugated element formed of strip metal in -which the depth of each l corrugation increases progressively from one end angle channel form to the edge having the V- form. These depths are shown as H and H respectively.

It will be obvious, however, that any convenient variation in form of the corrugations may be adopted to suit the circumstances of each particular case and the invention is not to be regarded as limited to the particular form above described.

In the construction described above, the corrugated elements 5 are manufactured from straight strips of metal, thereby reducing wastage of metal and overcoming many blanking diniculties.

What I claim and desire to secure by Letters Patent is:

' of said corrugation to the other, the pitch of each corrugation and the length of the cross-sectional contour in the pitch of a corrugation remaining constant throughout the length of the corrugation, the sectional form of the corrugation varying longitudinally thereof. the corrugations having a V-shaped contour at the ends disposed along one edge of the element, a three-sided right-angle channel contour at the other ends, and a three-sided channel cross-section with flat base and diverging sides between said ends, the said cross-section progressively merging into the said end contours. l

JAMES FRANK BELAIEFF.

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

UNITED STATES PATENTS Number Name Date o 1,429,644 Schreiner Sept. 19, 1922 1,914,077 Cluchey June 13. 1933 2,312,767 Meyerhoefer Mar. 2, 1943 2,153,120 Ludlow et al Apr. 4, 1939 2,344,588 Blauvelt Mar. 21, 1944

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