US2644675A - Heat exchanger - Google Patents

Description

Patented July 7, 1953 v. HE'T AEXCHANGER Sigmund Kopp, V`Fl'edoniri.,-N. Y., assignor'to Amer- Vvican lLocomotive'Company, New York, N. Y., a

corporation-of New York ApplicationNm/mber s, 1949, seriai No. 125.181 i This invention relates to heat exchangers;

The principal object of the invention is to provide a heat exchanger having a shell with an openable head closure and an improved type of fin tube-baffle assembly' therein which is easily assembled, which will function more effectively, and which is removable through'the head end Yof the shell for cleaning and repair, the bales'being thereafter easily removed from the 1in tube for cleaning, repair, replacement, or adjustment.

Other and further objects of the invention will appear from the following description, the accompanying drawings, and the appendedclaims.

Referring now to the drawing.

Fig. I is a foreshortened side View vof a heat exchanger constructed in accordance with the invention, shown partly in central section and with only a portion ofthe ns'shown, the remainder of the fins being indicated in dotted lines; Fig. II is a cross section through the exchanger taken on the line II-II in Fig. I; and Fig. III is a front elevation'of a baille plate. 'The forward and rear portions of the heat exchanger are shown respectively at the right and left of Fig. I. Fig. IV is a View of l-one ofthe sealing gaskets used on the tube sheet.

The heat exchanger includes a cylindrical-shell, generally indicated at I0, which has a main body Il, an end closure I2 permanently connected to the body at the rear end by a weld I3, and a anged end member I4 permanently connected to the forward end of the body by a Yweld fI5.

Fluid conducting U-tubes I6 and I'I are arranged to extend longitudinally of the shell with their forward ends supported in orifices I8 in the tufbe sheet I9. Orices I8 may be formed with annular grooves I8a therein for the reception of'correspending annular projections I9a on the tubes, which are expanded into the grooves upon assembly by swaging in the well known manner. Tube sheet E9 is clamped in operative position by a head-closure rigidlysecuredby boltsg2l to the bolting flange 22 voftheshell. Annular gaskets 23 and 24 are arranged respectively in recesses -25 and 26 formed for their receptionin the opposed faces 2l and 28 ofthe shell end member YIll and head closurel 20 respectively. Head closure 20 has a fcentralrecess 29` which forms' a chamber 3l) adjacent'the tubesheet. Fabricated integrally with the head closure at the horizontal centerline thereof and on itsrear face is a partition 3| which divides chamber 30 into compartments 32 and 33. Gasket 24 is formed with an integral central cross bar 24a Which'is disposed between partition 3| and tube 2 Claims. (Cl. 257-239) sheet I9 to'provide a seal between.comp:a'rtlrients 32 and`33. When the head closureis'clamped into operative position against the'.tubesflffe'etA partition 3l is brought into flush relation there-f with. Inlet passage 3,4 'andoutletpassag'i are threaded for the reception of fluidcondictors (not shown) forming partvvof a system to supply one of the'fluids'to be transferred througlr'the heat exchanger. Such inletr and outlet passages may, if desired, be provided with nozzles.

The inside diameters of the mainA.shell lciody'r II, end closure I2, and the an'ged'forwardfend member I4 are equal so that the inside' ofgthe' shell provides an unobstructed"Y andcontinuous wall extending from the forward faceof `I',h'e`bolt^y ing Vflange 36 to the. inside vcurvature of the. end cover I2. Inlet nozzle 3'I'and outletv nozzle B'S. communicate with the interior of themain shell body to supply a second fluid whiychwill pass' through the` shell for heaty exchange withthe' iiuid passing through the Uj-tubes inthe well known manner. End closure I2 and inlet nozzle 3l may be replaced by an end flange and opening similar to flange I4 and the opening at theforward' end of the shell so that the unit may be joined with another similar unit or with kother 'fluid con# tainers such as a pipe or tank. j

Each U-tube has bare end portions 39 and- 40; and mounted upon the tubes between such bare portions are extended surface elementsA in Vthe form of cross ns 4I to aid in the heattransfer function of the exchanger. 'Such nnslmayjbe helical,l (as shown in Fig. I) in which case they are of continuous ribbon-like construction; 'or they may 'be parallel, in which case theyfare fabricated individually and disposed alonfgthe tubes transverse to the axisthereof. jForLsteel tubes of 11/2 inches outsidediameter, finsofsheet ingot iron of approximatelygOlZ inch thickness,y 1/2 inch in height,.and 7to eachaxial'inchof tubing have been found to be satisfactory.

'The extreme forward end ,portions 2/of the tubes are flared back to prevent'fslippage of the tubes to the rear. such iiaring to be welded'vto'yt'he tube sheet, if desired. V'Alternatelygthe tub'esmay have straight end `portions 'disposed Vflush .with the outer face ofthe tube' sheet and welde; `se'-, curely into position. Baiile supportrnexnben 45 fisv disposed centrally of the U-tubes'equidistantfrom thev legs thereof and .f extends longitudinally through the shell. In `operative position.. therear end of member 45 is spaced at some distance from the Wall of closure I2 and its forward end is spaced closely to the tube sheet. Adjacent and immediately forward of the return bend 43 of the 3 lll-tubes, retainer pin 44 is mounted in the support member 45 to extend transversely to the axes of the tubes to prevent slippage or movement of the member 45 to the rear in response to fluid pressure upon the baflles. Support member 45 has another important function, as will later appear. In lieu of retainer pin 44, support member 45 may be threaded at its forward end and the tube sheet I9 provided with a tapped receiving bore for the reception of member 45 so that rearward slippage will be prevented.

A plurality of baffle members 45 are provided to perform the usual function of providing turbulence in the shell fluid. The construction of such .15Y

bales is an important featureofI the invention.

Each bafiie (seerFig. III) has the form of a slotted -plate of disc truncated so that its periphery is the arc of a circle somewhat greater'than 180. That is to say, the disc is a segment greater than a half circle. The slots 41 and 48 are disposed on opposite sides ofthe plate or disc center 49,

and each slot has a dimension equal to the outside diameter of thetube leg 56. The inner end of the slot is curved witha radius .equal Vto the Y radius of curvature of the outside'of the tube legs so that each baiiiemay be positioned across both legs of one U-tube with the curved ends of the slots flush against the tubes throughout half their circumference. The fingers 5|, 52, vand 53'of the disc are positioned (as shown in Fig, II) to extend across both legs of one U-tube Il and further to engage the vcorresponding legs of the adjacent tube I6.

The baffles are disposed alternately, one extending across the tubes from the left to the right (as l viewed in Fig. II) and the next extending across the tubes from the right to the left. Each baile has a circular aperture 54 at its center, the diameter of which is equal to the outside diameter of support member 45.

To assemble the heat exchanger unit, the U- tubes with the fins disposed thereon, are placed in parallel position in an assembly xture with the end portions of their legs extending through the orifices I8 in the tube sheet I9. The tube ends are thereupon rolled into the tube sheet and flared against the forward face thereof. The bafile plates or discs are then mounted in spaced relation across the Alegs of the tubes between fins, with the truncated edges of the alternate bafiles facing in oppositedirections. rlhe apertures 54 are in alignment, and the support member 45 is threaded therethrough from the end opposite the tube sheet in a tight t and moved to a position so that its end is adjacent the tube sheet. Pin 44 is inserted through the receiving orifice in the member 45. The entire iin tube-baiiie assembly may then be moved into the shell and the head closure clamped into position. The nozzles are thereupon connected to the sources of the two fluid supplies'.

Since the baille plates are machined to be positioned snugly against the inside walls vof the shell body, they will rest thereon and accordingly serve as supports for the U-tubes. As indicated inthe statement of invention herein, the exchanger may be dismantled by removing the head closure and sliding the U-tube-baiile assembly therefrom. The baiiies and fins lare then available for cleaning, repair, replacement, and adjustment;

v The mounting member 45 has been shown herein as circular in cross section andthe baiile plate central aperture 54 is circular to correspond thereto. Obviously, member 45 could be of other shapes, provided the baffle apertures 54 corresponded thereto so that mounting of the baiile plates upon the member could beeffected. Such mounting member, in whatever its shape, will serve as a deflector to prevent excessive iiow of shell fluid between the legs of the U -tubes, thereby directing the ow of fluid across the tubes in a more efficient manner for heat exchange purl pOSeS.

beunderstood that many and various changes and modifications in form, arrangement of parts and details of construction may be made thereto without departing from the spirit of the invention, and that all such changes and modifications as fall within the scope of the appended claims are contemplated as a part of this invention.

The invention claimed and desired to be secured by Letters Patent is: v

'1 '1n a heat exchanger of the class wherein a shell is provided with 'a removable head closure, a tube 'and baiiie plate'assembly removable from the shellasa unit comprising a tube sheet a plurality ofY fluid conducting U-tubes having 'legs anchored at their open ends to the tube sheet, aperturedbaiiie plates upon the U-tubes, a rigid member extending through the baiiie plate apertures,v and longitudinal movement restraining meansfor the rigid member comprising a pin disposed through the rigid member transversely to the axis of the legs of the U-tubes and adjacent the return bends thereof, said pin being adapted to engage such bends to prevent movement of the rigid member rearwardly in response to the pressure of the shell fluid upon the baie plates. i 2. in a heat exchanger yof the class wherein a shell is provided with a removable head closure, a tube and baiile plate assembly removable from the shellas a unitcomprising a tube sheet, a plurality of fluid-conducting U-tubes having legs disposed in parallel relation and anchored at their open ends to the tube sheet, a. plurality of apertured baiiie plates each shaped as a segmented disc and having a pair of parallel slots therein, said-plates being arranged transversely to the U- tube legs. with the slots in engagement with the legs, and a rigid member extending through the aperturesv of the baflie plates, and longitudinal movement restraining means for the rigid member lcomprising a pin disposed through the rigid member transversely to the axis of the legs of the U-tubes and adjacent the return bends thereof,

saidpin being adapted to engage such bends to prevent movement of. the rrigid Ymember rearwardly in response to the pressure of the shell uid upon the baffle plates.

SIGMUND KOPP. I

- References Cited in the file of this patent..

' e UNITED STATES PATENTS NumberY .I Name Date 724,750 Spindler Apr. '7, 1903 1,505,429 V Ripley Aug. 9, 1924 2,196,683 Pickstone Apr. 9, 1940 l2,399,484 Gunter Apr. 30,1946 12,418,405, Gunter et al Apr. 1, 1947v Tinker Feb. 21,1950Y

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