US2202494A - Baffle - Google Patents

Description

4 May 28, 1940. G. T. JAccKs BAFFLE Filed March ll, 1939 INVENToR en/:9e ZJ cac/a5' Patented May 28, 1940 PATENT oFFlcE BAFFLE George T. Jacocks, Larchmont, N. Y.,

assigner to The Lummus Company, New York, N. Y., a corporation o i Delaware Application March 11,

4 Claims.

passed in heat exchange relationship. Heat ex-4 changers of this type find use as surface condensers and feed water heaters.

It has been the practice to provide heat exchangers with longitudinal baiiles, the edges of which may be pressed into sealing engagement with the interior of the shell by means of externally operated mechanisms or by some form of resilient means such as springs. Neither of these expedients has been altogether satisfactory for the reason that the mechanisms involve complicated parts and have required attention from time to time to insurelproper functioning and sealing engagement, and the resilient means have failed to provide an adequate sealing pressure under all conditions. Those familiar with this art will understand that both of the prior sealing devices which have been briefly mentioned serve to apply pressure on a sealing strip positloned between the longitudinal edge of the baffle and the shell.

Therefore, it is a purpose of the present invention to provide a heat exchanger with a baille which will be eiectively sealed under all condi-l tions and which will not require any involved mechanism for its operation.

An additional object is the provision of baille means which will be thermally responsive so as definitely to improve the fluid tightness of the compartment seals under operating conditions.

A further specific object of this invention is the provision of a longitudinal baille for heat ex- 40 changes of extreme length and relatively small diameters.

These and other features of the invention including, certain details of construction and combinations of parts will be described subsequently with more particularity.

Reference will now be made to the accompanying drawing which illustrates a preferred embodiment of the invention, and'in which Fig. 1 is a longitudinal view partly in section of a heat exchanger with baille means;

Fig. 2 is an enlarged cross sectional along line 2--2 of Fig. 1;

Fig. 3 is a perspective view partly in section showing the details of the novel baille sealing means; and

view taken 1939, Serial No. 261,160

Fig. 4 is a fragmentary longitudinal section of 'the heat exchanger and baille.

In Figs. 1 and 2 there is shown a heat exchanger having a shell 5 of cylindrical shape and end flanges 1 and 9, respectively. The shell is d provided with an inlet connection II and an outlet connection I3, as shown in Fig. 2. At the right endy of the shell 5, as seen in Fig. 1, tube plate I5 is secured to the flange 9. A floating tube plate I1 is shown at the left end adjacent a shell 10 cover I9. In Fig. l, a cover or channel member 2l is shown adjacent the tube plate I5.

A plurality of tubes 23 extend longitudinally of the shell 5 in spaced relationship, and are supported by the plates I5 and I1. Two compartl5 ments, each of which contains a plurality of tubes 23, are provided by a longitudinally extending baille means 25 extending from the tube plate I5 to a point which leaves free a portion of the tubes 23 adjacent the floating plate I1 so as to zo aiord fluid communication between the compartments. Inletl connection II communicates` with one compartment and outlet connection 'I3 with the other. The bale 25 comprises a pair of parallel rectangular plates 21 and 29 supported 25 in spaced relationship by transverse bars 3|, 35, and 31 which abut a pair of longitudinally .extending spacer bars 39 and 4I. Spacer bar 31 engages the tube plate I5 (Fig. 4). Two longitudinal strips i3 and 45 serve as backing mem- 30 bers for a pair of opposed packing members 41 and 49 which extend beyond the baille plates 21 and 29 into sealing engagement with the interior of the shell 5, as shown in Figs. 1 and 2. It will be understood thatA the packing strips 'l1 and I9 33 may be formed from any suitable material, asbestos being preferred.

An important characteristic of this invention is the bi-metallic springs 5I which urge the sealing members into tight engagement with the shell o 5. As illustrated in Fig. 3, the bi-metalllc members are generally oval in shape with slightly spaced free ends and extend longitudinally of thebafe between the plates 21 and 29. Each of the 46 spaced bi-metallic springs 5I shown in Fig. 1 comprises an outer lamination 53 of a material of a predetermined expansion coefcient such as iron and an inner lamination 55 of a material of a greater coeilicientof expansion such as copper or other suitable thermally responsive material. Any suitable combination o inner and outer laminations may be used which will cause the springs- 5I to uncoil or expand transversely in response to increases in temperature so as to tighten the and -are adjacent the longitudinal strips 43 or 45 and throughout their lengths. Appropriate means such as a stud screw 51 having a lock washer 59 are used to anchor the springs 5l at uniformly spaced intervals to the longitudinal spacer bars 39 and 4l against which said springs react inA urging the sealing members 41 and 48 outwardly.

The corresponding ends of the longitudinal strips 43 and 45 and of the packing members 41 and 49 may be secured to the endmost transverse spacer bar 35 by screws 5i, 3l, as shown in Fig. 1. Note is taken that the other endmost transverse bar 31 is recessed at 33 and 55 on the face adjacent plate l5 to receive and retain bentoyer end portions 51 and 53 of the longitudinal strips 43 and 45, respectively.

While only one of the springs 5l, which is of oval shape with hairpin loops at its longitudinally disposed ends, has been described, it will be appreciated that'the others are alike in detail, including their anchoring means. y

In order to provide a unitary baiile construction of a simple and efficient nature, the parallel plates 21 and 29 have been secured to the spacer bars, 3l, 35, 31, 39 and 4l, by Welded joints 68 extending therethrough, as illustrated in Fig, 3.

The operation of `the thermally responsive means which has been employed to effect a positive sealing of the baille edges will be understood from the foregoing description of the details of construction, but it should be understood that the invention is not limited to specific details except as required by the appended claims.

What I claim is:

1. A heat exchanger comprising an elongated shell, spaced tube plates, a plurality of tubes extending between said plates, a baffle extending longitudinally of the shell and arranged to separate the interior thereof into compartments, a packing projecting beyond a longitudinal edge of the ballie, and means comprising a bimetallic element consisting of integrated strips of metals having different coeiiicients of expansion for positively urging the packing into tight engagement with the shell so as to seal the joint between the baiile edge and the shell, said means being effective under elevated temperatures within the range of the temperature of the heat exchanger.

2. A heat exchanger comprising a shell vwith a fluidinlet and a fluid outlet, spaced tube plates, a plurality of sets of tubes extending between said plates, a baille extending longitudinally of the shell and arranged to separate the interior thereof `into compartments each of which contains a set of tubes, a packing projecting beyond a longitudinal-edge of the baiiie, and a plurality of bimetalli'c spring means for positively moving the packing into sealing engagement at the joint betwen the baiiie edge and the shell, said spring means tending to expand with increases of ternperature, the expansion being suicient in the temperature range of the exchanger to complete the sealing engagement.

3. A heat exchanger comprising a shell having a fluid inlet and a fluid outlet, spaced tube plates, a plurality of sets of tubes extending between said plates, a. balile extending longitudinally of v the shell and arranged to separate the interior thereof into compartments each of which contains a set of tubes, packing projecting beyond each of the longitudinal edges of the baille, andv a plurality of bi-metallic springs of oval shape extending longitudinally of the shell for urging the packing into. tight sealing engagement with the adjacent portions of the shell, the bimetallic springs being of diierent metals integrated at their ends, the different metallic elements of the springs being arranged in such order that the tightness of the sealing engagement lwill be increased in response to an increase in temperature within the heat exchanger.

4. In a heat exchanger of the class described, having a shell, a tube bundle therein, a baille extending transversely of the shell and adapted to form separate compartments therein, said bailie having packing means adjacent the edges thereof and movable into contact with said shell, and a plurality of resilient elements securedl to said baiiie and adapted to urge said packing means against said shell, said resilient elements being comprised of a plurality of diierent metals integrated so that they tend to expand substantial amounts suiiicient to seal said gasket under increases of temperature within the temperature range of the heat exchanger.

GEORGE T. J ACOCKS.

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