US2306526A - Method of making heat exchange elements - Google Patents

Description

' c. Q. DALZELL srAL- I Dec. 29; 1942. 2,306,526

Y 'us'mop OF MAKING A yuan EXCHANGE ELEMENT I s Sheets-Sheet 1' Original Filed Nov. 30, 1938 Dec. 29, 194.2. a. DALZ ELL arm; 2,305,525

m'rrnon or mum A HEAT fixcn'gkem ELEMENT Orig inaIFiled Nov. so; 1938, Sheets-Sheet} INVENTORS. Dalzell aka/Zea Emu/n D 29, 1942-" c. DALZELL ETAL I 42,305,526

' ram-Hop oF- MAKING A HEAT Excamen mmmum 3 Sheets-Sheet 3 Original Filed Nov. so, 1933 T @%n% mh f Patented Dec. 29, 1942 i v mz'rnon or mxnwc near sxcmmcn ENTS Charles Brown .Dalzell and Ellsworth Wyman, Little Falls, N. Y., asslgnors to Cherry-Barrel! Corporation, Wilmington, Del., a corporation Original application Novcmber 30,.1938,Serlal No. 243,130. Divided and this application January I a raises, Serial No. 250,679 V j 5 Claims, (cl. 113-11 The present invention relates to heat exchange,

devices for cooling or heating liquids, such, 'for example, as liquid dairy products. More particularly the invention relates to the method of making a heat exchange element which may be a multi-sectioned, sanitary, heat absorbing or refrigerant expanding unit for the compressor type of. cooling machine adapted to be used in the top feed, trickle type of film coolers employing multi-unit, compact constructions. The present application is a division of our application Serial No. 243,130 entitled "Heat exchange device and filed November 30, 1938, which fully discloses and i. describes the heat exchange section and the process of making the section, which processis specifically claimed in this application. The heat exchange section as an article of manufacture is described and claimed in our co-pending divisional application.

The heat exchange section disclosed here is described and claimed as an article of manufacture in our co-pending application Serial No. 442,750 entitled "Heat' exchange element and filed'May 13, 1942'. 1

In heat exchange elements of the type referred i to, such as are used for the handling of food products, it is essential that the heat exchange sections be easily cleaned and of a sanitary con structionproviding smooth, unbroken surfaces freefrom cracks, crevices and shoulders for .the flow of the milk or liquid to beltreated and also to bracing elements and afeprovided with oppositely disposed protuberancesalong the flow passages of the refrigerant or heating-liquid, which flow 5 passages are angularly disposed to the direction of flow of the liquid being treated and' are formed by the application of internal; pressure after the various parts of the unit have been assembled. Such construction not only results in the marked 'eillciency ofthe operation of the element but also results in ,a marked saving in the assembly and fabricatiorrthereof.

"With the foregoing and other objects and important, features in view, the invention consists of certain novel features in the method of' construction of a heat exchange section 'as will be readily apparent upon the examination of the details of construction and arrangement and various combinations as disclosed inthe'flgures and'following description, all-of which will be first fully described and then specifically pointed out in the appended) claims, references being made to the accompanying drawings in which:

Figure l is'a side elevation of a multi-sectioned heat exchange/element embodying our invention.

Figure 2 is a plan view of the heat exchange element shown ,in Figure l.

Figure 3 is, a

I particularly emphasizing the inlet and outlet provide smooth passages for the flow of the heat exchange medium. The accompanying drawings illustrate the invention. 4

The principal objects of the present invention are to providea simple method of constructing a heat exchange element which may be 'made in one or morejoined sections with'equal facility;

in which embossed or corrugated sheets of metal are arranged face to face in opposed relation and sealed along predetermined lines, thus providing sealed liquid passages intermediate the plates; inwhich the bracing elements are substantially insulated from the h'eat exchange medium and so formed as to prevent the sections from freezing together, as well as toact as fluid control and distributing elements and spacing, means when .a lurality of elements is operated in close side-by-side position; and in which the embossings of-the sections are so constructed and arranged as to cause turbulence in the liquids flowing'through the interior of the sections and over, the outer surface of the sections.

A further object of this invention is to provide fore 'it reaches the upper portion of the upper- 7 connections for the liquid to be circulated through the interior of the sections of the element.

Figure 4 is an'elevatlonal view'of a portion of the liquid distributingland heat exchange element reinforcing bar or bracing mounted at the upper edge of the section, showingthe novel surface of the liquid distributing element and sche matically illustrating the dispersion of the liquid as it travels over the uniquely surfaced re,- inforcing or bracing portion of the element bemost sections of the heat exchange element. I

Figure iis a side elevation of a portion of a heat exchange section provided with novel, suran improved method or process of fabricating the I facing at spaced positions intermediate the 'treating liquid flow passages and'alongthe' path of travel of the liquidbeing treated to .disperse the same and more-uniformly distribute the liquid on the heat' exchange surfaces. I

, Figure 6 is a transverse sectional elevation, partially in brokenaway fragmentary section, of

tion taken along line t6 of Figure 1.'

a heat exchangeelement embodying our invenimproved heat exchange element whereby the side walls are formed, integrally with the end fragmentaryend view of the heat exchangeielement shown in Figure l and -sections flared.

Figure 7 is a transverse sectional elevation of the heat exchange element embodying our in vention, taken along the line 'l| of Figure 1.

Figure 8 is a transverse sectional elevation taken along the line 8-8 of- Figure 1.

Figure 9 is a longitudinal sectional plan taken Figure 11 is a transverse sectional elevation taken along line iI-H of Figure 10.

Figure 12 is a transverse sectional plan taken along line l2--i2 of Figure 10.

Figure 13 is a sectional plan of an end portion of a partially fabricated section showing the various elements of the structure including the end horizontal lengths 01 reaches of passage formed plates for sealing the ends of the sections in separated position in relative order of assembly.

Figure 14 is a fragmentary perspective view,

' partially in broken-away section of a portion of a heat exchange section, embodying-our invention.

Figure 15 is a longitudinal elevation-of a modiflcation of the heat exchange section embodying our invention. I

-Figure 16 is a transverse section elevation taken along line lS-IG of Figure 15.

Figure 1'? a transverse sectional elevation taken along line "-41 ofFigure 15;

Referring to the illustrations, the invention,

2 in its preferred form asl illustrated in Figure 1,

comprises a plurality of joined sections C. Each heat exchange element as illustrated may, when a multi-zoned element is desired, include several zones or sections C provided with independent flow passages 20. 'I'heseindependent sections of the elements or units are all identical with the exception of the topmost sections 2| of each unit, which topmost section 2i is provided at its. top e ge with acylindrical bracing and liquidd'spersin'g element 22 substantially devoid of heat exchange relation with the rest of the section to which it is aflixed. The flow passages in ,each' of the sections or zones of the multipleseciioned unit or element consist of outwardly bulged cooperative portions of two rectangular sheet metal stampings 22 and 24 intermediate a series of two sets, of continuously welded lines jo'n'ng the stampings and defining the flow passa es in between the twostampings 23 and 24.,

' In the illustrations, as clearly shown in FigurelO. the various adjacent horizontal reaches of the flow passages are formed in thejoined stampi' gs by certain portions of each" of the two sets of continuous weld lines. It is desired at this po nt to indicate that the various sections ofthe two sets of continuous weld lines intermediate the adjacent reaches of the flow passage as shown in Figure 10 may also be of a spot welding or sk'p welding" construction instead of a continuous seam-welded line. By such a "skip welding construction, it would be possible to provid by-- passes intermediate adJacent reaches of the zigzag flow passage 20 to facilitate the discharge oi refrigerant gas from the flow passage by-reducing the distance through which the 8% must 2 travel to reach the discharge outlet. The two ends of the continuous flow passage 20 intermediate the opposed stampings constituting the 7s passage 20 could be so arranged and constructed that the ends thereof would be located at 0990- site ends of the sections.

The zigzag passage 20 consists of a series of rosive metal such as stainless steel) provided with h a series of horizontal tiers of staggered rows 21 of outwardly directed, hollow, preferably semispherical protuberances""28 extending substantially across the face of the stampings 23 and 24 and leaving only vertical margins 29 at each end of the flat stampings. The rows 21' of protuberances are preferably three deep and the size of the protuberances 28 is such asito eifectively block the space intermediate two adjoining protuberances in an adjacent row 27, thereby eifectively diverting any liquid which may flow through between the protuberances in the adjoining row. The vertical margins at the ends of the stampings 23 and 24 are flared outwardly, forming flanges 30. End plates II with inwardly directed flanges 32 are afllx'ed to the free ends of flanges '30 as by weldings 32 between the end of the outwardly turned flange III of the stampings and the inwardly turned flange-32 of the end plates 3i, with the'exception of that portion of the flanges 30 immediately adjacent the inlet and outlet ports 25 and 26 for the passages 20.

Triangular webs or partition elements 34 are aflixed intermediate the flanges 20 at each end of each end plate 3|, thereby sealing the vertical space intermediate the flanges 30 and the end plates 3i, which space and itsd'eflning elements 30, 34 and Bi are substantially devoid of heat exchange relation with the passages 20 and the refrigerant or coofing medium or liquids which may flow through the passages. Each section or zone C of the heat exchange element'is provided with an inlet and outlet hinge arm I! and I6 respectively for establishing communication behowever, also be remembered that satisfactory heat exchange sections and multiple-sectioned tween the liquid passages 20 and for supporting the weight of the multiple-sectioned heat exchangeelement when mounted in ,a frame or -machine, and these hinge arms are joined to the sections at the inlet and outlet ports 25 and 2| respectively and in communication with passage 20. The inlet and outlet ports 25 and 26 are de-' fined by portions ofgthe flared flange II intermediate two triangular partition elements 34. adjacent the two ends of the passage 2| of the units. The ends of the hinge arms "and 26 arewelded to or otherwise satisfactorily aflixed to the outer edges of the flange l0 and partition 24 which define the inlet and outlet ports 28 and 26. "lhe two rectangular stampings 22 and 24 are in face to face contact with each other and the oppositely directed corresponding protuberances 28 are in exact transverse alignment. It should,

elements may be made by arranging the transi I asoauo 'ersely opposed protuberancesiin staggered or lther satisfactory relation one to another wherey turbulence of the liquids may be secured. On

he interior of each stamping the inner surface in the refrigerant or cooling liquid as it is speedly passed through the flow passage 20 when the :ections are placed in'operation as heat exchange :lements.

Inthe construction of a multi-zoned or multiiectioned heat exchange element several separate ndividual units or zones and 2| with a sepirate liquid passage 20 for each are welded together along their adjoining edges in superposed irder as shown in Figure 1. Each zone or sec- ;ion is provided with separate liquid inlet and )utlet connections in the form of hollow hinge arms 35 and 38 respectively. The spacing of the horizontal lengths of the flow passage 20 in each )f the zones or sections of the compound units or elements which are combined to form an opsrative unit, is such that when two sections are Ioinedrin superposed order, the separate adjacent horizontal elements of the flow passage '20 of the adjoining sections are spaced from each other equal to the spacing intermediate any two adjacent horizontal elements or' reaches of a flow passage in a separate section. Such construction facilitates the fabrication of a multi-zoned unit from single individual zones or sections.

The multiple-zone unit is desirable in that it shortens "the distance of flow of any portion of the heat exchange medium or refrigerant passing through the interior of thezone or section. A multiple-sectioned unit is also easily adapted to the use of a plurality of heat exchange media in that-any one or more ofthe zones of the'unit can be. supplied with any desired type of heat exchange medium while the remaining sections or zones of the unitmay ;be supplied with one or passed on to the upper surface .of the elemen 22. in small rlvulets, passes off of the lower portion of the element 22 onto the tcpportion of.

the upper zone 2| of the heat exchange unit.

A similar finish withhorizontal grains 38 1s provided on the outer surface of the walls or stamp'-' ings 2i and 24 of thesections 1C intermediate the horizontally extending reaches of the flow p ssages as shown in Figure 5. --After the liquid once passes onto the surfaces provided with the staggered rows 21 of pr'otuberances 28 it is maintained insubstantially uniform distribution a and active turbulence as it passes downwardly over'the surface of the sections C. This is true even whenthe sections are not especially grained. In the fabrication of each section or zone 38 of the heat exchange unit, it is preferable to use two .sheet metal stampings 23 and 24 pro vided .with tiers of rows 21 of protuberances 28. The stampings are identical so as, to constitute the reverse counterpart of. each other when they are assembled face tojface in reverse relation 4 as shown by Figures 11 and 12. The stampings 23 and 24 have in substance the plane of the sheet of metal from which they were stamped, and peripheral unstamped vertical marginal edges 29 of the juxtapositioned plates are cosheets are then welded together at their upper planar as shown by Figures 10 and 12. The

and lower edges along the weld lines 40 and 4| asshown in Figure 10, which weld lines exmore other types of heat exchange medium depending on the results to be accomplished and the liquid being treated on the outer surface of is first to receive the liquid to be' treated is provided along its upper edge with a horizontal,

longitudinally extending, cylindrical stifiening element 22' which is welded to the top edge of tend along these edges over to the vertical unstamped portions of the end margins. The internal horizontal fiow spaces 20 of the'sections C are then laid out and their edges sealed by seam-welding of the stampings along "the horizontal lines 42, 43 and 44 intermediate the tiers of superposed staggered rows 21 of the protuberances 28. It may be well to repeat at this point that the seam we'ldings 42,43 and 44, which "in the preferred embodiment of this invention are continuous seam welds, ma also take the formof interrupted weld lines which may be appropriately described by the term skip welding,

the section I48 with thecenter line of the element .22 in a horizontal plane and in vertical alignment with the vertical plane of the section 2|. By this arrangement the liquid supplied to the uppermost section 2! of each heat exchange unit will be directed against the surface of the stiffening element 22, preferably on both sides of the element 22, thereby assuring uniform liquid supply to each side of the topmost sections of th unit. To secure uniform distribution of liquid to be treated over the sides of the sections C the element 22 is provided with a grained finish as shown in Figure 4 in which the grains 39 extend in a directioncrosswiseto the path of I the fiow of the liquid passing downwardly from the source of supply over the stiflening element 22 toward the section 2| of the heat exchange unit. As the liquid particles contact the transversely directed grains 39 ofthe finish on'the element- 22, their fiow is hindered, tending to element 22 i obtained before the liquid which is', a

whereby a modified flow passage 20 provided with bypasses intermediate the horizontal reaches of adjacent sections would be provided to facilitate a more ready'escape of the evaporated .refrigerant from the various elements of the passage 20 toward the outlet. port 26. The joining of the "corresponding ends of one'of the group of alternate horizontal 'weld lines including the lines and 4! along their righthand end as shown n J in Figure 10 .by vertical weld line and joinhis the remaining horizontal weld linesiat theircorresponding opposite ends by 'vertical weld line 46, as clearly shown in Figure '10, defines the fiow passa'ge 20. In each instance the horizontal weld lines and the vertical joining lines are no closer to the remaining horizontal weld lines and their joining lines than the 'width'of a tier of rows 21 of the protuberances or bailles 28.

This arrangement of vertical'and horizontal weld lines defines a zigzag flow passage 20 with its open ends or ports 25 vand 26 at the lower and upper lefthand corners respectively of the stampings 23 and 24 forming the sections C of the heat exchange unit or element.

Having thus joined the stampings 23 and 24 along the weldlines just referred to, the vertical unstamped portion or edges 29 of each stamping are then flared outwardly to become flanges 30 as clearly shown in Figure 13. Triangular web or partition .elements 34 are provided at the ends of the vertical spaces intermediatethe outwardly turned flanges 30 at the opposite ends of the, sections C as shown in Figure 14, and also at vertical spaces intermediate the flanges 30 at the left end of the sections C immediately above and below the inlet passage 25 and outlet passage 26, and communicating with the opposite ends of the zigzag liquid flowpassage as is also clearly shown in Figures 1 and 14. Each section or zone is then provided at its inlet and I outlet openings and 26 with inlet and outlet hollow hinge arms 35 and 36 respectively, which are welded or otherwise satisfactorily afilxed to the free edges of the flanges 30 at the lower and upper lefthand corners of the sections C, respectively. The hinge arms and 36 are each welded to the free edges of the adjacent triangular parlines define theliquid flow passage 20. The spacing elements 48 used along the horizontal weld lines comprise straight, narrow, metallic strips of a thickness equal to the desired thickness of I the heat exchange medium passage 20. The ver-' titions 34 defining th upper and lower boundaries, respectively, of the inlet and outlet ports 25 and 26 to the liquid passage 20. End plates 3| with inwardly turned flanges 32 are then provided to enclose the vertical space intermediate the outwardly turned flanges 30 at either end of the section or zone C and between the tri-' angular partitions 34, which space is not already taken up by the hinge arms 35 and 36. The end plates 3| are flxed to the flanges 30 by welding 33 or other satisfactory means between the flange 32 and the outer free edge of the flange 30 as is clearly shown in Figure 9.

Each of the topmost sections 2| of the heat exchange unit comprised of a pluralityof sections C is also provided with a cylindrical, horizontally grained section and unit bracing element 22 extending across the uppermost edge of the section 2| intermediate the outwardly turned flanges 30. The horizontal rain lines 39 of the element 22 constitute liquid distributing and dispersing means to act on the liquid supplied to the element 22 in rivulets for uniform distribution throughout the entire length of the upper portion of the sections 2|. Similar grain lines 39 are provided on the surface of the stampings 23 and 24 intermediate the horizontally extending 'tiers of rows of protuberances 28. To complete each of these respective sections C, provided at their ends with end plates 3|, and only in the instance of the uppermost sections 2|, the end plate 3| is provided near its up er extremity with a latch or catch 41. Such a catch facilitates the proper 'mounting and positioning of the heat exchange unit when assembled in compact order in an enclosed heat exchanger of the swinging section type for which the unit is particularly-adaptable as is clearly shown in our copending application Serial No. 243,130.

To provide the individual zones or.sections C of the multizoned units or heat exchange device with internal'flow passages 2.0, the outlet hinge arms 36 of the completed multi-sectioned. elements are each sealed and the inlet hinge arms 35 are each connected to a source of fluid pressure, such as hydraulic pressure. The pressure is cupied by the vertical weld lines tical spacing elements 49 along the position ocin the preferred form and defining liquid passage 20 are straight along their outer edges 50, but are curved along theirinner edges 5| to facilitate the passage of liquid through the liquid passage 20. The spacer elements 43 are also of a thickness equal to the desired thickness of the liquid passage 20. The only other diflerence in' the modified form of section shown in Figures 15, 16 and 17, when compared to the preferred embodiment of th invention as previously described and shown in the preceding flgures, is the final shaping or bulging operation performed on the preferred embodiment of the invention, which shaping or bulging operation employing fluid pressure is not necessary in the modified embodiment of my invention as illustrated in Figures 15, 16 and-17 which employs the use of the spacing elements 48 and 49. 'In this later described modified type of section the bulging operation is not required in that the flow passages 20 are formed by and defined by the spacing strips or elements 48 and 49.

It will 01" course be evident that the heat exchange device and th unique elements incorporated therein are particularly adapted for use in the treatment of foodstufls. such as milk, requiring sanitary treatment, and

the entire device is so constructed as to incorporate only sanitary features to make it acceptable for such use. However, the heat exchange element is also well adapted for use in the heating or cooling of other liquids which do not necessarily require sanitary handling, but in which heating or cooling operation it is desired to secure a high rate of heat transfer and in which use it may also be desired to assemble the individual elements in close side-by-side compact relation as illustrated in a heat exchange machine fully described in our copending application Serial No. 243,130 of which this application is a division.

Each of the heat exchange sections is provided at either end with a transverse bracing ele ment or end plate afllxed to the outwardly flared vertical ends of the stamplngs constituting the walls of the individual heat exchange sections.

adjusted until the portions of the plates or stampings. 23 and 24 intermediate the weld lines definingthe liquid flow passages 20 have been bulged outto the desired shape as shown by the sectional drawings, Figures 7, 8, 9 and 14, depict-ing internal views of the sections, and Figures 6 and 14.

depicting the bulged effect on the liquid passage boundary portions of the stampings 23 and 24. However, 'he stampings 23 and 24 may be stamped originally with the bulged portions to form the flow passages 20, and in such instances hydraulic" pressure would not be required to form the ln-- ternal flow passage 20. I

The outwardlyflared ends of the stampings, as well as the end plates, are united in sealed relation one to another and are substantially devoid of heat exchange relation with the heat exchange mediumpassing through the liquid flow passages on the interior of the respective sections. Being thus substantially devoid of heat exchange relation, there will not be a tendency of crystallization of spattered liquid to form on the outer sur face of the outwardly flared flanges at the ends of the sections of the multi-sectioned heat exchange elcment, or on thcbracing end plate aflixed thereto, thereby aiding in the satisfactory operation of the heat exchange element.

Various changes in the heat exchange devices as shown and described to explain the invention in V tinuous zigzag flow passage inlet and outlet fittings.

and stampings.

the improved method of making the heat exchange section may 7 the common knowledge of those skilled in the art and yet come within the scope of the invention as set forth in the appended claims. We claim as our invention: l. The process of making a sheet metal heat asoaaae Y tire length of the sheets, welding the facesof the be made in accordance with space intermediate exchange section which consists in forming a substantially fiat sheet metal stamping provided with longitudinally extending superposed tiers of staggered rows of semi-spherical protuberances,

superposing two of said stampings one upon another with corresponding protuberances in opposed relation, welding the stampings together along certain contiguous lines which form continuous weld lines defining a zigzag flow passage between the two stampings, sealing one end of said zigzag flow passage, and then separating said sheets at all points except said weld lines by introducing a fluid 'under pressure between said plates through said remaining open end of said zigzag flow passage.

2; The method of making a heat exchange element for liquids which comprises, stamping superposed tiers of staggered rows of outwardly extending protuberances in a rectangular sheet of metal, placing a second sheet of metal of the same size and stampings face to face with the first sheet, sealing the top and bottom edges of a the two sheets substantially throughout their entire length, welding the faces of the sheets together at separate intervals, flaring the vertical edges of each sheet outwardly away from the corresponding edge of the adjacent sheet; securing inlet and outlet fittings to the two ends of a fiow passage between the two sheets defined by ing one or more zones and joining l5 7 to the top edge of the top sheets together at separate intervals, flaring the vertical margins of each of the joined sheets outwardly away fromieach other, securing partition elements to said flared margins intermediate the same at the extreme. ends of thefree vertical v said margins, sealing inlet. and outlet fittings passage between the two joined sheets which flow-passage is deflnedby the lines of welding between the sheets, securing end plates to the free edges ofthe said margins spanning the-free space intermediate the flared margins, superposthem together. at the adjacent edge, securing a bracing element zone, sealing all the outlet fittings of the severalzones, and then separatingthe sheets of the severalzones of the section by introducinga fluid under pressure between the several sheetsthrough said inlet openings. v

4. The method of making a sheet metal heat exchange section which consists in superimposing the lines ofiwelding between said sheets, closing one of said fittings, and introducing a fluid ,un'der relatively. high pressure between the sheets through the other fitting to force the sheets. apart 7 at all points except at points of welding to form a series of, outwardly bulged flow passages with adjacent passages communicating one with another at their ends only, thereby forming a conintermediate said 3.) The method of making a multi-zoned heatexchange section for liquids, which comprises stamping superposed tiers of staggered rows of i outwardlyextending sealing the top thri'iughorut ensheets together substantially sheet-like stampings having fluid baiiie means on their outersurfaces, securing said stampings together along continuous. same to define fiuidflow space therebetween and to provide a unitary double walled plate-like structure having an inlet and outlet opening, applying bracing elements ,at either end of said stampings'substantially devoid of heat exchange relation with the fluid flow space intermediate said stampings, sealing the outlet opening, and separating said stampings at all points except said lines securing the same together by introducing fiuid under pressure between said stamp- I ings through said inlet opening.

5 The method of making a sheet metal heat exchange section which comprises superimposing twosheets of metal, both of said sheets being Pro vided with staggered'rows of fluid baflles on their respective surfaces,

said sheets together along lines intermediate said I rows of baflles and about'the margins of the same and outlet passages intermediate into the space thereproviding inlet said plates which open between,- applying high pressure between the between the welds, to the endsof said plates.

faces through said passages toseparate them and applying bracing elements sheets of 'metaLsaid bracing elements being substantially devoid of heat exchange relation with cmms BROWN D ELL-SWORTH-WYMA'N.

to the two ends of-the flow" ,lines intermediate the .i

welding'the joining faces of the space intermediate the

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