US 3111982 A
Description (OCR text may contain errors)
3 Sheets-Sheet 1 Filed May 20,- 1959 INVENTOR. K0437 flzaezav BY 2 W Nov. 26, 1963 K. ULBRICHT CORRUGATED HEAT EXCHANGE STRUCTURES 3 Sheets-Sheet 2 Filed May 20, 1959 .r 4 w y 7 r m Y B Nov. 26, 1963 K. ULBRICHT 3,111,982
CORRUGATED HEAT EXCHANGE STRUCTURES Filed May 20, 1959 3 Sheets-Sheet 3 I N V EN TOR V4 ae/av/r FIG 7 aer FIG.8
United States Patent Fil edl May 20, 1959, Ser. No. 814,635 Claims priority, application Germany May 24, 1958 3 Claims. (Cl. 165-166) The present invention relates, in general, to heat exchangers and, in particular, to heat exchangers of the corrugated plate type for fluid media.
In plate heat exchan ers which comprise a plurality of plates having parallel corrugations or grooves to limit the cross sectional areas traversed 'by separate gaseous and/ or liquid media, great difliculties were presented when it was desired to obtain the advantages of the counter-flow principle. These difliculties occurred in the end regions of the heat exchangers and related to the separate supply and discharge of the two media being utilized.
As a result, the cross current principle was frequently utilized. However, the cross current principle is less advantageous than the counterflow principle because of the relatively greater flow resistances and the irregular temperature diiferences between the two media at the various points of the exchangers.
In view of the foregoing, it is an object of the present invention to provide means obviating these and other disadvantages of prior art heat exchangers.
It is another object of the present invention to provide means in a plate heat exchanger utilizing the advantageous counterflow principle while avoiding the previously described diificulties of construction.
It is a further object of the present invention to provide means conducive to the attainment of a highly economical, efiicient and relatively simple heat exchanger of the described type, which can be manufactured and sold at a relatively reduced price.
Briefly described, the present invention comprehends a construction wherein parallel longitudinal channels are vformed by a stack of corrugated plates to provide a central zone for the counter or parallel flow of two separate media, while collecting cross sectional areas are provided at both ends of the stack for each row of channels, a frontal outlet and inlet being provided for one medium and a lateral outlet and inlet being provided for the second medium.
Each element of the heat exchanger comprises a pair of plates in opposing mirror relation. Some of the plate elements are provided, at both sides of the active central zone of the two media, with corrugations which are offset in a lateral direction so that the corrugations of adjoining elements are staggered laterally by about half a division between thecorrugations.
It is possible to construct a corrugated heat exchanger pursuant to the present invention in several different forms. Thus, all of the plate elements can be provided, in the end regions thereof, with corrugations which are offset, in lateral direction by a quarter of the division between the corrugations, alternate opposing plate elements being turned by -180 degrees about their longitudinal axes.
It is possible also to provide each second plate element, in the end regions thereof, with corrugations which are offset, in lateral direction, by a half division between the corrugations.
The cross sectional flow areas in the end regions of the plate elements, for the medium which is to be supplied and discharged in a transverse flow direction, are terminated by fillers. These fillers likewise preferably comprise plates which are corrugated in longitudinal direction and toward the side opposite the inlet and outlet, respectively. These fillers are provided preferably with an inner edge which is curved to enhance a favorable deflection of the respective medium from a transverse to a longitudinal flow direction and vice versa.
The above and other objects of the invention will become further apparent from the following detailed description, reference being made to the accompanying drawings, showing preferred embodiments of the invention.
In the drawings which illustrate the best modes presently contemplated for carrying out this invention:
FIG. 1 is a side elevation of a corrugated plate element in which the corrugations are not oifset;
FIG. 1a is an end view of the plate element shown in FIG. 1;
FIG. 2 is a side elevation of -a corrugated plate element in which the corrugations are laterally offset, pursuant to the present invention;
FIG. 2a is a cross section-a1 view taken on the line B--'B of FIG. 2;
FIG. 2b is across sectional view taken on the line A--A of FIG. 2;
FIG. 3 is a side elevation of a corrugated plate element, as in FIG. 2, having flat longitudinal edges;
FIG. 3a is an end view of the element shown in FIG. 3;
FIG. 4 is a side elevation of a filler;
FIG. 4a is an end view of the filler;
FIGS. 5 and 6 each illustrate a portion of a stack of elements shown in cross sectional views corresponding to the sections taken along the lines B-B and A-A, respectively, of FIG. 2.
FIG. 7 is a fragmentary enlarged detail of FIGS. 5 and 6;
FIG. 8 is a schematic view showing the flow paths of the two fluid media through a heat exchanger pursuant to the present invention; and
FIG. 8a is an end view in perspective of a pack of corrugated elements and fillers embodied in the invention.
Referring now to the drawings in detail, each element 20 of a corrugated plate heat exchanger 22 (FIGS. 5 and 6), pursuant to the present invention, comprises a pair of rectangular plates '1 each formed of thin sheet metal, or other suitable sheet material. The plates oppose each other in mirror-like manner and are provided with corrugations 3 which extend longitudinally thereof.
As best seen in FIG. In, this arrangement of the plates defines a series of parallel longitudinal channels 2 in each plate element 20. The corrugated sections or por tions 2a of the two plates which face each other, or abut, can be secured together by butt welding, or the like.
This is done only to stiffen or rigidify the two plates and to hold them together, since it is not absolutely 3 necessary to separate the channels within each medium where they are traversed by the same medium. -As a result, the securement of the two plates in each element can be limited to specific points thereof.
After each element 20 is produced from a. pair of plates 1- 1, the corrugations 3 thereof are laterally offset. This is best shown by element 20A in FIGS. 2, 2a and 2b. As seen in MG. 2, the central region or area designated a extends over the major longitudinal extent of the element 20A. The end regions are designated c-c, and two transition regions between each end region and the central region a are designated bb. The corrugations are indicated by the lines 3. These lines extend in longitudinal direction through the central region a from which they extend obliquely in lateral direction through each transition region b, at each end of the central region, and they extend again in longitudinal direction through the end regions.
As a result, and as best seen in FIGS. 2a and b, the channels 2 are staggered with regard to each other in the regions a and c, in the transverse direction, it being apparent that each channel is deflected upwardly from the central region a to the opposite end regions 0, as a result of its lateral deflection through the transition regions b.
Lln the present instance, each channel is staggered by a quarter division of the channel spacing. After the channels are offset, as in FIG. 2, the longitudinal side edges -4 of each element 20A are pressed flat, with the necessary pressure, so that they are forced toward each other and are devoid of corrugations, as best seen in FIGS. 3 and 3a, wherein the element so treated is designated 20B.
Several plate elements 20B are arranged in pairs as shown at 20B, FIG. 6, to form a plate pack 22, and each second or alternate element is turned or rotated by 180 degrees about its longitudinal axis so that the corrugations of adjacent elements are each offset from the central area :1 toward the end areas c thereof in opposite direction.
This defines in each plate pack 22 separate longitudinal channels 5 which are formed only between adjacent central areas a of adjacent plate elements, as best seen in FIG. 5. This arrangement also defines in each plate pack 22 continuous intervals 6, which are formed from the transition regions b through the end regions 0 over the entire width of the elements. Said continuous intervals 6 are open at both sides 6a thereof, as best shown in FIG. 6.
In order to close the intervals 6 in the longitudinal direction of the elements, in the opposite end areas thereof, and in the transverse direction of the elements, toward one side edge thereof, fillers 7 (FIGS. 4 and 4a) constituted by corrugated plates, are inserted between adjacent plate elements 208, as best shown in FIG. 6. The inner closed edge 8 of each filler, facing into an interval or spacing 6, is arcuately ourved so that one of the fluid heat exchange media, which is introduced into the spaces 6 in a direction to effect transverse flow through the plate pack 22, is deflected from a transverse flow direction at the inlet 23 ('FIG. 8) into the longitudinal flow direction of the active center region a of the plate elements and from the latter the flow is deflected again into a transverse flow direction at the outlet 24 (see also FIG. 8a).
This is best shown in FIG. 8, wherein the fluid heat exchange medium M which flows through the intervals or spaces 6 between adjacent plate elements, is designated by the flow line M It will be noted that said flow line is of general 8 shape, extending from inlet 23 in a direction transversely of the pack 22, then being deflected, as at 25, by the fillers 7, into a longitudinal flow path, as at 26, from which it is again deflected, as at 27, by fillers 7, into a transverse flow path 28, for exit at the outlet 24. Instead of having the entrance 23 and the exit 24 at opposite longitudinal side edges of the pack 22, as shown in FIG. 8, they can both be arranged at the same side edge so as to produce a U-shaped flow pattern for medium M Consequently, in either case, it will be apparent that the flow pattern M for the heat exchange medium is a transverse-longitudinal-transverse flow path through the pack 22.
The other medium, which flows through the closed channels 2 and 5, flows in a substantially straight flow path longitudinally of the pack, from an inlet 32 at one end to an outlet 33 at the other end thereof, as indicated at M in opposition to the 'longitudinal flow path portion 26 of path M The flat edges 4 of the elements 208 are welded, as at 29 (-FIG. 7), to bars 9 interposed therebetween so as to form closed Walls 30-31 at the opposite longitudinal side edges of the pack 22. It will be understood that closed wall 31 is interrupted at one end area c to form the inlet opening 23 and closed wall 30 is interrupted at the opposite end area c to form the outlet opening 24.
The opposing ends of the pack can also be provided with stiffening walls 10 (FIG. 6) if the heat exchanger is to be subjected to high internal pressures. The entire pack can be housed in conventional manner, in a pressure-resistant housing that is closed on all sides, for example, by being mounted in a pipe.
Instead of offsetting the corrugations 3 by a quarter division or spacing therebetween, it is also within the scope of the present invention to provide half the elements with corrugations which extend longitudinally thereof and to provide the other elements with corrugations which are offset by half a division in a lateral direction in the regions b and c. In this case it is necessary only that one element, which is not offset, alternate with one element which is offset, so that it is immaterial with what side they oppose each other.
While the present invention has been illustrated and described in connection with corrugated plates, it is not limited thereto. It is within the scope of the present invention to utilize plates provided with corresponding grooves and strip tubes.
Various changes and modifications may be made without departing from the spirit and scope of the present invention and it is intended that such obvious changes and modifications be embraced by the annexed claims.
Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:
1. A heat exchanger comprising at least two pairs of longitudinally elongated plate elements, a first element comprising a pair of corrugated plates disposed in touching contact with their corrugations disposed opposite in mirror-like arrangement and including substantially horizontal end corrugated sections and an intermediate oflset substantially horizontal central corrugated section, the respective corrugations of said central section being connected to respective corrugations of said end sections by oblique sections, a second plate element substantially similar to said first plate element and disposed in an inverted position adjacent said first plate element with the outwardly extending corrugated portions in touching contact at said end sections but offset in an opposite manner at said intermediate and central sections to define a flow path therebetween, the corrugations of each of said pairs of plates defining continuous longitudinal channels for the flow of a fluid medium therethrough, the spaces between pairs of plates defining at said central and intermediate sections a path for the flow of a second fluid medium therethrough, and a filler plate arranged on each end of said pairs of plates and defining an inlet for directing fluid laterally inwardly to said central section and an outlet for directing fluid laterally outwardly from said central section, each of said continuous longitudinal channels being in communication with each other at locations centrally between and closely adjacent said filler plates in the region of said inlet and outlet.
2. A heat exchanger according to claim 1, wherein the corrugations in the intermediate sections of each of said plate elements are bent obliquely about a quarter of a 5 division between corrugations toward an opposite side of said heat exchanger.
3. A heat exchanger according to claim 1, wherein said filler plates are disposed on opposite sides of each end of said central section and provide means for directing a 10 fluid medium around one of said filler plates inside said central section and thence directing said fluid around the other of said filler plates and for discharge from said heat exchanger.
References Cited in the file of this patent UNITED STATES PATENTS Behringer June 11, 1912 Meveu Dec. 27, 1921 Hume Oct. 9, 1928 Shipman June 8, 1943 Burns et al Sept. 4, 1951 Frey et al Oct. 30, 1956 Person Mar. 10, 1959 FOREIGN PATENTS Italy Jan. 25, 1945 Great Britain Mar. 19, 1952