CA1117521A - Header construction - Google Patents

Abstract

Abstract of the Disclosure There is disclosed herein an improved header construction for use with fin and tube type heat exchangers which allows for an increased number of radiating fins to be incorporated into a heat exchanger of any predetermined size. This header construction includes a base member having a plurality of tubular projections extending outward from a center inter-connecting portion and a pair of oppositely extending substan-tially parallel spaced apart flange portions extending generally perpendicular to the interconnecting portion. A cover member is also included which has an interconnecting portion with a pair of similarly generally perpendicularly outwardly projecting substantially parallel flange portions which are spaced apart a distance slightly less than the distance between the flange portions provided on the base member so as to be received between and adjacent to respective of the base member flange portions. An optional generally S-shaped clip member is provided which surrounds the lateral sides and end portions of each of these flange members and is brazed thereto create a multisurface sealing relationship between the flange portions of the base member and cover member.
The tubular projections provided on the base member are adapted to be directly connected to the respective tubes of the fin and tube heat exchanger so as to eliminate the need for any transition or intermediate header members thereby enabling this space to be used for additional heat radiating fin portions. Additionally, an optional longitudinally extending baffle and retaining clip assembly is disclosed which enables a single header assembly to provide both inlet and outlet header chambers. Thus, this header construction allows heat exchangers having increased heat radiating capacities to be fabricated within given dimensional sizes.

Description

1~75'~

Backgro~md and Swl ary of the Inv ntiorl ~ le present invention relates generally to heat exchangers such as are employed for various uses in ~ransfcrring heat between non-mixing fluids and more particularly to improved header constructions for SUC]l heat exchangers of the fin and tube type construction.
I-leat exchangers of various types are employed in a great variety of applications ranging from extraction of heat from combu~stion process such as for building heating to cooling of various fluids such as lubricants, compressed gases or the like. One heat exchanger con-struction commonly employed particularly in applications wherein a gaseous medium is to be passed over the exterior surface ~hereof is the fin and tube type construction. Typically such fin and tube type heat exchangers will have a plurality of fluid conducting tubes or conduits arranged in parallel side by side rol~s extending both longitudinally and transversely of the heat exchanger. Headers are generally connected to opposite ends of these tubes -to conduct the fluid to the heat exchanger and the cooled fluid back to the source thereoft In one form, these headers are fabricated from tubing or pipe of a diameter suficiently large to provide the desired flow capacities However, in large capacity heat exchangers having multiple longitudinal rows of tubes, it becomes impractical to directly connect each tube to It the header. Thus, in such applications intermediate headers are often ~t, S

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provicle~ intelconll~ct tr.ln~versc rows of tubes and provide a s-ingle lollg-itll(lirla'l t'OW 0~' tlll)cs for collneCtion to the primary or main hea~er. Such a constlllction ;s ~lisclosc(l in Paten~ 3,515,208, issucd June 2, 1970 to ~J. K~l~az;n. As thc~e in-te~nediate headcrs arc not generally provided with heat radiating fins, they do not provide an effective heat tr~msfer surf,ace area cornmensurate with the space which they occupy. ~lus, in order to provide a heat exchanger having a given efficiency~ i~ is necessary to increase the physical size thereof which necessitates increased costs in the form of additional framing members and further requires additional space for installation of such units.
Space limitations are becoming an ever increasing problem particularly-for heat exchangers which are designed for use in machinery manufactured for the heavy construction industry in that Federal regulations are requiring more and more pollution and noise abatement equipment of various types to be installed on such equipment. As this additional equipment often requires substantial space and ~urther in that it is generally desirable to keep the overall size of such equip-ment as small as possible, the available space for installation of such heat exchangers is becoming significantly reduced. Further~ the addition of such pollution equipment often requires substantial amounts of additional power be dra~n from the engine which increases the amount of heat which must be dissi~ated by the heat exchanger while also restricting the amount of air which may be passed over the heat exchanger.
Thus,-not only is the available space for installation of $uch heat exchangers being reduced, but the demands for heat dissipating capacity are increasing. It therefore becomes important to provide heat exchangers having increased'operating efficiencies in order to meet these reduced z~

~spacc re~ ;remerlt.s al~d incl~c.lse(l heat dissir)at-ing requ:i.r~lrlellts.
'Illc prese1lt invel7t:ion provi.dcs <l bcacter construction which overcomes these problellls by e:limina~ r]g the necd for ~he :interm~diate header member, rl~e presellt :invcntion provides a base member which allows for direct connect;.on of any nwnber of longitud:inally extending rows of tubes directly to the primary or mai.n inlet and outlet headers thereby allowing the space prcviou~sly consumed by these intermediate header members to be effectively used for additional heat radiating fin members. Further, the unique header construction allows a header to be fabricated of any desired width without concern that the flow capacity thereof may be either excessive or insufficient as the height of the header may be easily modified ~o provide any desired volume and hence flow rates therein. ~le header comprises two generally U-shaped channel members one of which has a width slightly less than the width of the other so as to allow the outwardly projecting flange portions thereof to nest between and adjacent to the outwardly projecting flange portions of the other member, A clip member may be e.mployed between these adjacent flange portipns and will serve tp mechanically secure these adjacent flange portions together prior to and during an oven brazing operation as well as to provide a multisurfaced seal between these members. Alternatively? the adjacent fIange portions may be mechanically secured by tack w~ldincJ ar~d -~ereafter sealed by a hrazi,ng operation. The base channel rnember is provided with a plurality of tubular projections extending outward there~rom which are adapted to telescopically receive or be received by the respective tubes ~rom the fin an~ tube construction thereby allowing the fin portions to approach within a close proximity to the header itself. Further, these generaLly tubular projec-tions are provided with a hydraulic radius ak their junction with the base member so as to insure a smooth laminar fluid flow between the header and the tubes. Also, a unique baffle assembly is provided which enables a single header assembly to provide both inlet and outlet header chambers such as may be desirable for two pass counterflow heat exchanger~
Thus, the present invention allows fabrication of a heat exchanger having subs~antially greater numbers of heat radiating fins and therefore substantially greater capacity for a given size heat exchanger. Further, the header is extremely economical to construct and may be easily fabricated from whatever desired gauge channel or flat formed stock is n,ecessary to resist the pressure forces which will be generated during operation thereof as well as providing a strong frame for'supporting and protecting the core. Also, the use of the generally S-shaped clip member 'insures a high integrity joint as substantial amounts of brazing material will be deposited -to create a positive, long-lasting and durable sealing relation-ship between the adjacent flange members and portions of the clip member.
In summary of the above, therefore, the present invention may be broadly defined as providing a heat exchanger comprising:

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a heat exchall~Jirl~J cor~ meml~ havi.lly a plu:ra.Li.t;y of fluid concluctiny conclu.i.t members ~-;urrounded hy hcat radi.at.in~ ~in members; at leas~ one header .inc].uding a base member haviny first and second generally paral:lel su~.stan~iall~ planar spaced ~.ancJe porti.ons alld an in~erconrleclincJ portion, ~he intcrconnecting portion h,lving a plurali-ty of spaced outwardly extending tubular projec~ions i~nte~rally formed on the inter~
connecting portion, each of the tubular pro~ections having a . substantially constant taper and forming a relatively smoothly radiused shoulder at the juncture with the interconnection portion; a cover member comprising first and second genexally parallel spaced flange portions and an interconnecting portion, the first and second flange portions of the base member disposed in at least partially overlapping relationship to respective or the ~irst and second flange portions of the cover f . member, retaining means retaining the overlapping flange portions in close proximate relationship and securing means disposed between each of the overlapping portions of the ~lange portions and securing the overlapping portions in a sealing relationship;
and the header being sealingly connected to one end o~ the plurality of fluid conducting members with the tubular projections bèing i~ telescopic nested relatLonship with the conduit members, the taper o~ the tubular projections being operative to prevent the fluid conducting member from extending into the interior of the header whereby the smoothly radiused shoulder may operate to insure relatively smooth fluid flow between the conduits and the - header.

, Additional ad~arltages and features of the present invention will become apparent from the subsequent descrip~ion and the appended c:laims ~ken in conjunction with the accompanying drawinys.

Brief l)cscril)tioll u r tl~e l)ra~ing.s l~igl~rC I illustrat~s ~ he~ excilanger of -th~ fiil arld tube construction having inlet and out].et headers in accordarlce w:ith the prcsent i.nvention;
Figure 2 is an enlarged sectioned view of both the intake and outlet headers of Pigure 1, the section being taken along a vertical plane passing through the longitudinal axis of the heat exchanger of Pigure 1 and passing through the center of one transverse row of tubes;
Figure 3 is an enlarged view of a portion of a fully assembled header in accordance w:ith the present invention shol~ing the clip member and overlapping flange portions prior to brazing and including a pair of brazing rods;
Figure 4 is a view similar to that of Flgure 3 but illu~strating the assembly after being subjected to a brazing process9 Figure 5 is an enlarged cross sectional view of the clip member;
Figure 6 is an enlarged sectioned view of 2 portion of a heat exchanger illustrating another embodiment of the present invention;
,Pigure 7 is an enlarged fragmentary sectioned view of a portion of a header assembly in accordance wi,th the present invention being subjected to a spot welding operation;
Figure 8 is an enlarged fragmentary side elevatisnal view of a portion of the header asse,mbly illustr~ted in Pigure 7;
Pigure 9 is an exaggerated sectional view of the header assembly of Figure 8? the section being taken along line 9~g thereof;

r:igure lO is a ~i~c elcvatiollal v;e~ of ~ h~at cxchangcr havills a port.io~ I`CO~ hrokcrl a~ay <In~l ill.ustrating ano~her ~mbodim~nt of the pr~s~nt inv~nt:ion;
Figure ll is a transversc sectiollal-view of the header assembly illustrated :in ~;.gure 10, the section being taken along line 11-11 thereof; and Figure 12 is an enlarged detail view of a portion o the header assembly illustrated in Figure 10, Description of the Preferred Embodiments -Referring now to Figures ]. and 2~ there is shown a heat exchanger indicated generally at 10 having an inlet 12 and an outlet header 14 connected at opposite ends thereof and having a core portion 15 fabricated from a plurality o stacked sheets 16 each of which is formed with a plurality of tubular projections 18 telescopically arranged in a nesting relationship to define a plurality of fluid conducting conduits andsurroundingheat dissipating fins 20, The construction o this stacked fin and tube core portion is described in greater detail below, The intake header 12 is comprised of a base member 22 having ` a pair of leg or flange portions 24 and 26 projecting generally perpen-dicularly outward f.rom an interconnecting portion 28 to form a generally U-shaped structure. Interconnecting portion 28 is formed with a plurality of spaced tapered tubular projections 30 extending outward therefrom in a direction opposite that of flange portions 24 and 26 each of which is connected to one of the conduits 18 forming in part the heat exchanger core 15. A cover member 32 is also provided which is shaped simil~rly to thak of base member 22 having a pair of leg or 1ange ~ 75~

portions 34 and ~>6 r~rojeeti]-lg gcrler.llly perl)cndicu],arly outward from an ;n~erconnecting poltion 38. Ilowe-ver, intCrCOnneCtirllJ porti,on 3R
has a widtll slightly less tlr.ln thc width of i,nteIco~llec~ing portiorl 28 so as to allol~ botll flange portions 34 and 36 ~o be placed betwcen ~d ilmnediately adjacent respective of fl~nge portions 24 and 26, ~ Itlet headc-r ~4 disposed at the opposite end of heat exch~lger core 15 is of a similar construction also comprising a base member 40 having a pair of leg or flange portions ~2 and 44 projecting generally perpendicularly outward from an interconnecting portion 46.
Also, similar to base member 22, interconnecting member 46 is formed with a pluraIity of tapered tubular projections 48 extending outward therefrom. A second cover member ~9 is provided w}lich is substantially identical to cover member 32 and therefore has like portions indicated by like numerals primed. Headers 12 and 14 are substantially identical in construction e~cept for the shape of respective tubular projections 30 and 48 extending outward therefrom, As best seen with reference to Figure 2, base member 22 is pro`vided with tubular projections 30 having a slightly converging outward taper. Each of these tubular projections is open at the outer end and prefeTably is integrally formed Wit}l interco~mecting portion 28 such as by use of a stamping operation employing progressive dies or by any other suitable means, Tn order to assure a smooth fluid flow between the header and each of the tubular projections, a rounded shoulder portion 50 is provided at the juncture of each o tubular pro-jections 30 with interconnecting portiPn 28, The outer terminal end portion 52 of each of these tubular porjections is open and provided with ~3L~ 7 ~

a slight ra-lially iin-~ar(lly anrl~i].lr ~evcled ~(lge 54 whicll facilitates the assembly opcration l)y gui(l;ilg tubular l)rojcc-tions 30 into a tele~
scopic nesting relationsllip l~;th thc outcr ~ds 5~ of the core po~tion CO~ Uits.
In order to facilitate assembly of base member 22 and cover member 32 and also to insure a fluid tight seal is created therebetween, a clip member 56 is interposed between the adjacent flange portions 24, 34, 26 and 36 respectively of base member 22 and cover member 32.
Clip member 56 is generally S-shaped having three spaced apart sub-stantially parallel ;nterconnected portions 58, 60 and 62 which define two relatively deep slots 64 and 66 therebetween. Flange portions 24 and 26 of the base member 22 are received in slots 64 and engage outer portion 58 and intermediate portion 60 of clip member 56 while flange portions 34 and 36 of the cover member are received in respective slots 66 and engage inner portion 62 and the intermediate portion 60 of the clip member. Clip member 56 will generally be of a length coextensive with each of the base and cover members and will preferably be fabricated from a metal material such as steel for example~
Referring now to the outlet header 14, as also best seen in Figure 2, tubular projections 48 of base member 40 are provided with a diverging outward taper which enables them to telescopically receive tubular projections 18 of the core por~ion 15 interiorly thereof, Also, similar to that of base member 221 the juncture between tubular projections 48 and interconnecting portion 46 of base member 40 are provided with a rounded annular $houlder 67 so as to insure a smooth fluid flow from the heat exchanger conduits into the header thereby maximizing the fluid flow through the heat exchanger, 7~5~

~ c tl~e llea(ler con~itruction i.]]u.~trated in l:i.gurc 2.is suital):ie rOI use in any convcnti~nc~ in arl(l tube type heat cxchangcr core constructioll, it ;s pa-l~icularly dexir~blc in a construction wherein the fins and tub~ portions are integra:l1.y fo-rmcd by fal>ricating a plurality of sheets eacil]laving integrally fo~led tapered tubular prujections whicll are then stacked with each of the tapered tubular projections being arranged in a ~utual a.ligned nested relationsh.ip so as to define a conduit therethrough. Typically, sucll constructions are fabricated by first manufacturing the plurality of integrally formed ~ube and fin members and stacking them in a substantially parallel nested relation-ship~ The two base members 22 and 40 are then assembled to the core structure after which a cover member and associ.ated clip members may be assembled to one of the base members by first assembling two clip members to each of the flange members of the base member~ As seen in Figure 3, a pair o~ brazing rods 68 and 70 of a length substantially equal to that of the respective flange portions and clip members are also inserted in each of the slots 64 and 66 between the terminal end portions 72 and 74 of respective flange portions 26 and 36 so as to be retained in place thereby, Thereafter a plurality of brazing rods are inserted in each of the conduits of the core 15. The other header assembly may then be completed in substantially the same manner as described above.
A framing member 75 which extends parallel to the nested tubular pro-jections 18 and between each of the two headers may then be welded to the opposite ends of headers 12 and 14 to retain the heat exchanger assembly together during the brazing operation, ~raming members 75 also serve to prevent distortion of the core structure during the brazing 5~L

operat:io?l as ~cll a.~ l~rovi~ <~ o~lrltil~ tructurc to sccurc thc COlnl)leted he.ll: e,~C11.111g(~r ~i tliin Wh~ CVCI- C~Uil~mCrll: it :i.'; intCn(led to l)e used. Oncc tlle llea~k~r s~ l core strllcturc :is :Eully ~.ss~mbled as describe~l above with the l:)razing rods app-ropriately placc~ therein, the en~ire structlllc is slo~ly moved through a brazing furnacc at which time the brazing rods 68 and 70 ~ rnelt causinK the material therein to flow between adjacent surfaces of the Q allge portions 26 and 36 and portions 58~ 60 and 62 of clip member 56 and seal each of the joi.nts.
As best seen in Fi.gure 4, the brazing rod material 70 flows completely around the end portion 74 and side surfaces 76 and 78 of flange portion 36 as well as the facing surfaces of portions 62 and 60 of clip member 56 thereby forming a very long sealing surface between the interior and exterior of the header, Similarly, brazing rod material 68 flows completely around end portion 72 and side surfaces 80 and 82 of flange portion 26 as well as facing surfaces of portion 58 and 60 of clip member 56 thereby forming a si.milar extremely long sealing surface for the base member of the header.
It should also be noted that the cover members 32 and 49 of these headers may be provided with any desired n~mber and type of connections such as for incoming and outgoing fluid conduits as well as drain plugs or the like in any desired conventional manner.
While any suitable material may be used for fabricating clip member 56, it has been found that for use in such a brazing operation a steel base material 84 having a relatively thin copper coating 86 com-pletely surrounding the exterior surfaces thereof, as shown ;n Figure 5, produces excellent results în that the copper coating combines with the brazillg rocl ~o ~Ollll a~l e.Y~ l`cmely .';trollp, dur-ll)Le bon(l i)etwe(~n the adjacellt fl.all~e l~ort;.ol~s. I:urtl-)cr, the .~-~;ha~c of the cl:ip .~erves to mechall.icc~lly r~t~lin th~ g port.ions in a cl.o~e rela~ion.~ urinK the brazing pTOcess therel)y prevent;.llg any def.o-rmation of t}lC lcg portions from their generally perpendicular positi.on with respect to their comlecting portions l~hich may result in an incomplete or weakened seal therebetween.
l~ile only three laterally spaced apart rows of core tubes are provided in the embodiment il].ustrated and described herein) it is possible to manufacture heat exchangers having any desired number of laterally spaced rows by merely extending the width of both the base and cover member. Furtller, the header itself may be easily designed to acco~nodate any header flow capacity necessary for a specific applicatlon by merely increasing the length of the flange portions of the cover member thereby providing a greater enclosed volume, It should also be noted that while the headers have been described herein for use with heat exchanger cores comprising stacked sheets having integrally formed nesting tubular projections? the same construction and assembly method may be used in any type heat exchanger having cores which include fluid conducting tubes which must be connected to a header, Typically the end portions of the header construction will be closed by welding plates thereover or forming flange portions on the base member and/or cover mem~er and welding or brazing the seams.
The individual components of this header construction may be fabricated of any desired material suitable for the particular application such as for example a steel o~ relatively heavy yauye. The use of the heavy gauge will assist in preventing the header from defornring shc~Jd excessive pressure build up in the heat exchanc3er duriny use. Further, the fact that double seals are provic~d bet~teen the acljacent leg portions of the base memker and intercannecting member will also assist in preserving the integrity of the header should this pressure develop during use.
Referring now to Figures 6 through 9, there is shown a portion of another embodiment of a heat exchanger 88 in accordance with the present invention co~prising a oore structure 90 of the fin and tube construction sImilar to that of core structure 15 described above includiny heat radiating fins 92 and inteyrally formed nested tubular projections 94. However, in this embodlment, each of the tubular projections 94 are provided wqth a diametrically extending portion 96 having a pair of vanes 98 provided thereon.
m is vaned tube oonstruction is substantially identical to that disclosed in Patent No. 3,311,165 issued March 28, 1967 to J. Karmazin~ Heat ex-changer 88 also includes a header 100 campris~lg a base member 102 having a flange portion 104 and cover m~mber 106 having a flanye portion 108 overlapping flange portion 104 all of which is substantially identical to that described with reference to base me~ber 40 and cover member 49 except in this e~boai~ent no clip mmber is employed. Rather, overlapping flange portions 104 and 108 are brought into mutual engagement and retained together by tack welding these portions together. Preferably, the tack welding will be accomplished by spot welding flange portions 104 and .~ I ~ .

~ 7 ~

.l08 togetllcr a~ a plura:lity Or sl)aced apalt loca~:ions along the length thereo.E.
As il].ustrated ;n l::i.gure~ 7 tilrougll 9, this spot welding operatioll may be perfo1~led by bringi.TIg a pair of electrodes 110 and 112 into engagemeJIt Witll opposed flallge portions 104 and 114 of base member 102 after cover member 106 has been assembled thereto with flange portions 108 and 116 in overlapping relationship therewith. A slight clamping pressure may be exerted on :flanges 104 and 114 by electrodes llO and 112 so as to force them into engagement with respective adjacent flanges 108 and 116. As voltage is applied between electrodes 11~ and 112, current will flol~ through both base member lOZ and cover member 106, The current concentrations in the area immediately surrounding respective electrodes 110 and 112 will cause a welding betl~een adjacent flange .
portions 1047 108 and 114, 116. Preferably, a plurality of spot welds 118 w~ll be applied to the header assembly at spaced apart locations along the entire length thereof, the spacing being sufficient to insure that the overlapping flange portions are maintained in close.proximity to each other, Adjacent flange portions 104, 108 and 1147 116 may then be sealed by a brazing process which will result in a deposit of brazing material 120 being drawn and/or flowing between the overlapping mutually engaging surfaces of these flange portions and around spot welds 118 so as to effectively and securely seal the joint therebetween, ~le spot welding of these flange portions will not only retain them .in close proximity to one another cluring the brazing process thereby insuring that the brazing material w.ill be able to create a strong seal along substantially the entire overlapped surface but will also add strength to the cc~mpleted header construction. In order to msure sufficient ~14~

br<lzing materi.~ is l~rcsellt ;lt tllesc loc~t:ions it may be ~esirable to place a sm.~ ant:ity Or coppcr p~ste ~lorlg tl~e e~xtcri.or seam hetwec :flangcs 104 an(l l()8 along l~itl) a braz:i.rlg rod. l1~e coppcr pastc will scrvc to rctain the braz;ng rod in position dur:ing the brazing operation.
The metllod of assemb~ g l~eadcr member 88 to core struc~ure 90 is substantially identical to that describecl ahove with reference to the headers of Figure 2. It should also be noted that a base member 102 includes substantially identical tubular project;.ons as those provided on base member 40.
As is apparent rom the above description, the use of this header construction eliminate~s the need for the previously mentioned intermediate header members thus allowing the space occupied by such members to be more effectively utillzed by heat radiating Eins ~hereby allowing the efficiency of a given sized heat exchanger to be substantially increased, Further, the total number of joints in the heat exchanger is re.duced and a$ these joints represent the weakest link, the overall integrity of the hea~ exchanger is al~o improved. Also, the forming of the tubular projections integrally Wit]l t~e base member enables the juncture to be easily ~ormed with.a smoothly merging radius which pr.omotes-maximum fluid flow between the conduits and header$.
Referring now to Figures 10 through 12 yet another embodiment of the present invention is illustrated being indicated generally at 122. In this embodiment heat exchanger 122 comprises a core portion 124 of the fin and tube type having a header assembly 126 secured to one end thereof, Header assembly 1.26 includes a base member 128 substantially identical to base members 28, 46 and 102 described above and therefore further description thereof is ~nitted as being unnecessarily -15 ~ .

rc~l~m(lall~. Simil~lrly, a ~ovel mellll)cr l,3~) i.s cll~o prov;ded w}lirh is substantially idcntical to cover memhcr 38, 3~' and 106 and theret'ore ~urther descril)tion o~ which is l)e'licve(l urlnccessary. Ilowever, in thi,s embodiment, cover member 130 is provided wi,th an additional centrally disposed longi~udinally extendillg fk~lge portion 132 arranged in substanti~lly parallel spaced relationship to outer flange portions 134 and 136, Flange portion 132 will pre~erably be fixedly secured to cover member 130 by welding sudl as is indicated at 133 or in any other suitable manner so as to provide a fluid tight seal along its entire length, A generally U-shaped channel member 137 is also provided having a flat bottom portion 138 which is secured to base member 128 and from which a pair of slightly spaced apart flange portions 140 and 142 project outwardly so as to define a cha~mel therebetween.
Flange portions 140 and 142 are spaced apart a distance substantially equal to or only sligh~ly greater than the thickness of flange portion 132, the outer end 144 of which is adapted to be received therebetween.
Preferably~ channel member 137 will be secured to base member 128 by spot welding as indicated at 139. A suitable copper pasteorother brazing material 148 may be applied between end 144 of flange portion 132 and cha,nnel m,ember 137 at the time of assembly of cover member 130 to base member 128. Thereafter, the header assembly may be completed by either spot welding technique as described above or alternat;vely the S~clip may be ~mployed in the aboye described manner. As the completely assembled heat exchanger 122 is subjected to an oven brazing operation, brazing material 148 will flow around end portion 144 thereby forming a fluid tight seal with channel member 137.
Additional brazing material 150 will be allowed to flow between bottom ~16-5~

portioll 138 .~ sc mclllb(r l2~ ~o as t:o creclte a rluid tight seal ~l~erebet~.~cen.
Ihus, flall~e po-rtion 1.S2 ~ill separat( l~eader ~ssembly 126 into h~o separate ch~1l1)ers 15~, 156, cach of which communicates with a predetermined number of flU;d conduits 158 making up core 124, Suitable inlet ~md outlet connections 160, l62 may be provided communi-cating with respective chambers 154, 156 and a suitable fluid return 164 provided at the opposite end of fluid conduits 158 thereby providing a t~o pass counterflow heat exchanger having a single header assembly having both inlet and outlet chambers associated therewith. Additionally, it should be noted that fl~nge portion 132 not only operates to divide header assembly 126 into separate chambers but also acts as a reinforcing member thereby allowing header assembly 126 to l~ithstand greater fluid - pressures without distortion as well as enabling lighter guage materials to be used in ConStructIon thereof.
While it will be apparent that the preferred embodiments of the invention disclosed are well calculated to provide the advantages and features above stated, it will be apprecia-ted that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

Claims (19)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A heat exchanger comprising:
a heat exchanging core member having a plurality of fluid conducting conduit members surrounded by heat radiating fin members;
at least one header including a base member having first and second generally parallel substantially planar spaced flange portions and an interconnecting portion, said interconnecting portion having a plurality of spaced outwardly extending tubular projections integrally formed on said interconnecting portion, each of said tubular projections having a substantially constant taper and forming a relatively smoothly radiused shoulder at the juncture with said interconnection portion;
a cover member comprising first and second generally parallel spaced flange portions and an interconnecting portion;
said first and second flange portions of said base member disposed in at least partially overlapping relationship to respective of said first and second flange portions of said cover member, retaining means retaining said overlapping flange portions in close proximate relationship and securing means disposed between each of said overlapping portions of said flange portions and securing said overlapping portions in a sealing relationship; and said header being sealingly connected to one end of said plurality of fluid conducting members with said tubular projec-tions being in telescopic nested relationship with said conduit members, said taper of said tubular projections being operative to prevent said fluid conducting member from extending into the \
interior of said header whereby said smoothly radiused shoulder may operate to insure relatively smooth fluid flow between said conduits and said header.

2. A heat exchanger as set forth in Claim 1 wherein said securing means includes clip members surrounding end portions of each of said overlapping flange portions.

3. A heat exchanger as set forth in Claim 2 wherein said securing means further includes sealing means disposed between said overlapping flange portions and said clip member.

4. A heat exchanger as set forth in Claim 3 wherein each of said clip members includes interconnected first, second and third portions, said first portion of each of said clip members being disposed adjacent to an interior surface of respective said first and second flange portions of said cover member, said second portion being disposed between one surface of respective said first and second flange portions of said base member and another surface of said first and second flange portions of said cover member and said third portion is disposed adjacent to another surface of said first and second flange portions of said base member,

5. A heat exchanger as set forth in Claim 3 wherein said sealing means comprises a brazing material.

6. A heat exchanger as set forth in Claim 1 wherein said tubular projections are integrally formed in said base member, are divergingly tapered outwardly and receive one end of each of said conduit members therein.

7. A heat exchanger as set forth in Claim 1 wherein said tubular projections are integrally formed in said base member, are convergingly tapered outwardly and are each received within one end of each of said conduit members.

8. A heat exchanger as set forth in Claim 7 wherein said at least one header is an inlet header and further including a second header including a base member having a first and second generally parallel spaced flange portions and an interconnecting portion, said interconnecting portion having a plurality of spaced tubular projections, a cover member comprising a first and second generally parallel spaced flange portions and an interconnecting portion, said first and second flange portions of said base member disposed in at least partially overlapping relationship to respective of said first and second flange portions of said cover member and securing means disposed between each of said overlapping portions of said flange portions and securing said overlapping portions in a sealing relationship: each of said tubular projections of said second header being divergingly tapered outwardly and receiving another end of said conduit members therein.

9. A heat exchanger as set forth in Claim 8 wherein said tubular projections of. said at least one and said second headers are sealingly connected to said conduits by brazing.

10. A heat exchanger as set forth in Claim 1 wherein said retaining means includes a plurality of spaced apart spot welds securing said overlapping portions in close proximity and said securing means comprise brazing material disposed between said overlapping portions of said flange portions to thereby seal said overlapping surfaces together.

11. A heat exchanger as set forth in Claim 1 wherein said header includes means defining first and second chambers.

12. A heat exchanger as set forth in Claim 11 wherein said chambers each extend longitudinally in said header and are disposed in side by side relationship.

13. A heat exchanger as set forth in Claim 12 wherein said means defining first and second chambers comprises a third flange portion secured to a selected one of said cover member and said base member and a channel member secured to the other of said cover member and said base member, an outer end of said third flange portion being received in said channel member so as to divide said header into two chambers.

14. A heat exchanger as set forth in Claim 13 wherein said retaining means includes a plurality of spaced apart spot welds securing said overlapping portions in close proximity and said securing means comprise brazing material disposed between said overlapping portions of said flange portions to thereby seal said overlapping surfaces together.

15. In a heat exchanger of the fin and tube type, a header construction comprising:
a base member having first and second substantially parallel flange portions spaced apart a predetermined distance and an interconnecting portion;
said interconnecting portion having a plurality of integral spaced tapered tubular projections adapted to tele-scopically nest with respective conduits of said heat exchanger, each of said tubular projections having a smooth rounded shoulder portion at its juncture with said interconnecting member;
a cover member having first and second substantially parallel flange portions spaced apart a distance less than said predetermined distance and an interconnecting portion;
said first and second flange portions of said cover member being disposed in at least partially overlapping relation-ship with said first and second flange portions of said base member;
a pair of elongated generally S-shaped clip members, each of said clip members having first, second and third interconnected substantially parallel portions, said first and second flange portions of said cover member being disposed between said first and second portions of respective ones of said clip members and said first and second flange portions of said base member being disposed between said second and third portions of respective of said pair of clip members; and means securing adjacent portions of said clip portions and said flange portions in a sealing relationship.

16. A header construction as set forth in Claim 15 wherein said securing means comprises a brazing material which is caused to flow between said adjacent surfaces.

17. A header construction as set forth in Claim 15 wherein said tubular projections are convergingly tapered outwardly so as to be received within respective of said tubes of said heat exchanger.

18. A header construction as set forth in Claim 15 wherein said tubular projections are divergingly tapered out-wardly so as to receive said tubes within said projections.

19. In a heat exchanger of the fin and tube type, a header construction comprising:
a base member having first and second substantially parallel flange portions spaced apart a predetermined distance and an interconnecting portion;
said interconnecting portion having a plurality of integral spaced tapered tubular projections adapted to tele-scopically nest with respective conduits of said heat exchanger, each of said tubular projections having a smooth rounded shoulder portion at its juncture with said interconnecting member;
a cover member having first and second substantially parallel flange portions spaced apart a distance less than said predetermined distance and an interconnecting portion;
said first and second flange portions of said cover member being disposed and secured at a plurality of spaced locations in at least partially overlapping relationship with respective of said first and second flange portions of said base member;
a third flange portion sealingly secured to a selected one of said cover member and said base member between and in substantially parallel relationship to said first and second flange portions;
a channel member secured to said interconnecting portion of the other of said cover member and said base member, said third flange portion being received and sealingly secured within said channel; and sealing means securing adjacent portions of said first flange portions and adjacent portions of said second flange portions in fluid tight relationship.