US1868661A - Heat exchanger - Google Patents

Description

July'26, 1932. o. w. HEIMBl-:RGER

HEAT EXCHANGER Filed Dec. 1o. 1.961

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ik gn xNvEN-roR ATTORNEYS Patented July 26, 1932 UNITED STATES PATENT oEFlcE OSCAR W. HEIMBERGER, 0F WEST BRIGHTON, STATEN ISLAND, NEW YORK, ASSIGNOR T0 THE GRISCOMRUSSELL COMPANY, 0F NEW YORK, N. Y., A COEPORATION 0F DELAWARE HEAT EXCHANGER Application led December 10l 1931. Serial No. 580,072.

This invention relates to heat exchangers of the type in which a plurality/ of tubes are placed in a containing shell and which are commonly known as shell-and-tube or surface type heat exchangers.

This type of heat exchanger is used prin-y cipally in transferring heat between two liquids, such as in oil refining operations and the like, and in transferring heat between a liquid and a gas as for example, in steam power plants and industrial establishments.

When used for transferring heat between two liquids, one liquid is passed through the shell of the exchanger and comes in contact with the outside surfaces of the tubes and the other liquid is passed through the tubes and the transfer of heat between the liquids takes place through the walls of the tubes; In transferring heat between a liquid and gas or vapor, the gas or vapor is usually passed into the shell and the liquid forced through the tubes.

In the particular form ofshell-and-tube or surface type of heat exchanger with which Ithis invention is concerned, the tube bundle is secured at each end in a tube sheet and means are provided within the shell containing the tube bundle for conducting the Huid so that it makes two or more passes through the tube bundle before being discharged.

Inasmuch as thetubes are usually'made `to provlde a heat exchanger in which the of a different metal than the shell and normally operate at a temperature different from that of the shell, the relative thermal expansion between the tubes andthe shell must be compensated for. To this end, one end of the tube bundle is anchored at its tube sheet to the shell, while the other end of the tube bundleand its tube sheet is supported so as to allow it to move bodily within the shell in response to thermal expansion or contraction of the tubes relatively to the shell and vice versa.

This floating tube sheet carries a cap which forms with the tube sheet a sealed chamber at the end Aof the tube bundle for receiving the circulating Huid4 discharged from one portion of thetubes and redirecting it into another portion of the tubes. This cap moves with the Hoating tube sheet and the entire organization at that end of the tube bundle is known as the Hoating-head. Also, the tube bundle is of a diameter suHiciently small to permit ready removal of the ventire tube bundle as a unit, including the tubes and both tube sheets, for purposes of repair and periodic cleaning, especially when oil and other viscous liquids are used therein.

In order to effectively seal the connection of the Hoating head, a very tight joint between them must be provided. It has been common practice heretofore to'employ clamping devices which hold the cap and the Hoating tube sheet securely together and yet may be released readily to enable the heat exchanger to be readily disassembled for cleaning and removing and replacing tubes and the like. These clamping means usually include various kinds of' so-called sectional rings to enable ready disassembling of the Hoating head and these have been found to be generally satisfactory except that the sectional clamping rings have a tendency to cock, rotate, or cant about the inner periphery of the tube sheet, which they are intended to clamp squarely and securely to the cap, when the clamping means, such as bolts, are tightened down.

It is the principal object of this invention Hoating head is so constructed that canting or cooking of the clamping rings is prevented or reduced to an unobjectionable degree, without sacrificing the ready assembling and disassembling of the Hoating head, which is so necessary to secure easy access to the parts of the heat exchanger for cleaning and repair purposes.

In accordance with this object the heat exchanger includes a tube bundle having tube sheets at each end, one tube sheet being anchored .to the shell in the usual way and the other tube sheet being arranged to Hoat in the shell to accommodate relative thermal expansion between the tubes and the shell. The cap, into which one portion of the tubes discharge and which redirects the Hui'l into another portion of the tubes, engages the outer face of the ioating tube sheet and the floating tube sheet is held against the cap in clampin relation by a sectional ring which embraces t e peripheries of the cap and the ioating tube sheet in the manner of a cirl ring of the form described, a segmental clamping ring or separate clamps, one for each setsorew or bolt, may be employed.

With this construction, the parts of the sectional ring are securely held together by its connections with the outer face of the cap and the inner face of the ioating tube sheet, and these connections brace the sectional ring segments, orseparate clamps, against movement in all directions, so that cooking or canting of the inner edge thereof about the inner edge of the outer periphery of the floating tube sheet is eiectively prevented and the cap and the tube sheet are clamped squarely and securely together. This construction, however, permits ready removal of the cap from the floating tube by simply loosening the set screws from the cap suiiciently to permit withdrawal of the reversely turned inner or opposite edge of the sectional ring parts or the corresponding segment or separate clamp from the groove on the inner face of the tube sheet, and then lifting these elements from their embracing engagement with the cap and tube sheet. The tube bundle including the iioating sheet, is of such dimension as to permit ready Withdrawal thereof as a unit from the shell for repairing and cleaning purposes.

For a better understanding of -the invention, reference is made to the accompanying drawing, in which Figure 1 is a longitudinal section of a heat exchanger embodying the construction of the present invention;

Fig. 2 is an expanded view of the floating head, consisting of the floating tube sheet securedv to one end of the tube bundle, the ca and the clamping means;

ig. 3 is a reduced section through the modified or segmental clamping ring;

Fig. 4 lis a faceviewof one of the clamping segments;

Fig. 5 is an edge View of a slngl'e clamp form of clamping means; and

Fig. 6-is an inside view thereof.

In the drawing, the heat exchanger includes the longitudinal cylindrical shell 10 Instead of employing a split sectional recaen tube sheet 14 and at the left-hand end into a movable or floating tube sheet 15. In order to cause the liquid entering at the inlet 11 to pass longitudinally of the shell 10 and the tube bundle 13, a baille plate 16 extends from the fixed tube sheet 14 centrally of the shell 10 and terminates at a point near the opposite end thereof. l

The other fluid, such as oil for example, enters at the right-hand end of the exchanger through the inlet 17, which delivers it to a chamber 18 from which it flows into the tubes-of the tube bundle 13 lying on the upper side of the dividing partition 19. The liquid passes through these tubes and is discharged into the floating chamber 20 at the left-hand end of the exchanger, which is formed between the cap21 and the floating tube sheet 15, to which it is secured in a manner to be described. This chamber redirects the iiuid into the tubes of the lower portion of the tube bundle 13, whereby the liquid is returned to the right-hand end of the exchanger and discharged into a chanber 22 on the lower side of the partition 19, from which it passes out of the outlet 23.

The shell 10 is provided at its right-hand end with a connecting flange 24 and at its left-hand end with a similar connecting flange 25. The fixed tube sheet 14 is clamped rigidly between the flange 24 and the castings 26 containing the inlet 17' and the outlet 23, by means of a plurality oflong bolts 27. The shell 10 is closed at its left-hand end by means of a large dome-like cover 28, which is secured to connecting ange by means of bolts 29. The liquid passing through the shell 10 is free to circulate within the domelike cover 28 around the floating head of the tube bundle formed by the cap 21 and the floating tube plate 15.

This floating head is supported centrally in the Adome-like cover 28 and the tube bundle 13 is supported centrally in the shell 10 by lmeans of an annular disc 30 mounted on the tube bundle 13 near the left-hand end of the exchanger. This disc has a large central opening for the free passage of the fluid in the shell and is slidable axially in the shell 10 in response to the relative thermal expansion between the tube bundle 13 and the shell 10 and remaining stationary parts of the exchanger. This relative thermal expansion between the tube bundle 13 and the shell 10 and remaining partsof the exchanger takes place for the reason that the tubes 13 and the shell 10, being made of dierent materials have and the inner edge of this rim is seated in a peripheral recess 32 formed in the outer surface of tube sheet 15. The opposite or inner face of tube sheet 15 is provided with an annular slot or groove 33. Encircling the peripheries of cap rim 31 and floating tube sheet 15 is a sectional or split ring 34, whose inner edge is provided with the radial flange 35 and whose outer edge is provided with the radial ange 36, flanges 35 and 36 making the sectional ring 34 of generally channel or in- Verted U-shaped cross-section.

` The inner flange 35 of the sectional or split ring 34 is provided with a reversely turned lip, rim or projection 37, which is adapted to fit into the angular groove 33 of the inner face of floating tube sheet 15, as shown especially in Fig. 1. When the two parts of the sectional or split ring 34 are placed around the peripheries of cap rim 31 and floating tube sheet 15, the flange 35 overlaps the inner face of floating tube sheet 15 and the flange 36 overlaps the outer face of cap rim 31, so that the channel or U-shaped sectional or split ring 34 spans orembraces the floating tube sheet 15 `and cap rim 31, preferably around their entire peripheries.

Threaded through 'the outer flange 36 of the sectional or split ring 34 is a series of equally spaced set screws or set bolts 38, whose tips bear against the outer surface of the cap rim 31 when the set screws or set bolts 38 are tightened down.

It will be seen that when the sectional or split ring 34'is emplaced on the floating head in the manner described, this ring is held on one side against radial spreading by the interlocking cooperation of lip, rim or projection 37 with the groove 33 on the inner face of floating tube sheet 15, and that the outer side of the sectional or split ring 34 is likewise kept from spreading radially by the spaced set screws or set bolts 38. It will also be seen that when the set screws or set bolts 38 are tightened down, the eripheries of the floating tube sheet 15 and) the cap rim 31, which cooperates with the recess 32 of the former, are drawn squarely and tightly together against movement in all directions. Also, the sectional or split ring 34 is prevented from rocking, cocking or canting about the inner edge of the outer periphery of floating tube sheet 15, since the tips of set screws 38 hold it against any radial movement, such as any tendency to rock, cock or cant.

In assembling the floating head of the heat exchanger, the 1nner edge of rim 31 of cap 21 is placed in the recess 32 of the floating tube sheet 15 and the two halves or parts of sectional ring 34 are placed around the peripheries of the abutting cap rim 31 and tube sheet 15, this sectional or split ring spanning or embracing the edges of the cap rim 31 and floating tube sheet 15 in the manner illustrated in Fig. 1, the lip, rim or projection 37 of inner flange 35 thereof resting in the groove 32 in the inner face of floating tube sheet 15. It is Ethen only necessary to tighten down the set screws 38 in order to hold the halves of the sectional ring 34 together and draw the cap 21 and floatmg tube sheet 15 securely and squarely together to form a tight and leakproof joint. In disassembling the floating head after removing the dome-like cover 28 of the exchanger, it is only necessary to loosen the set screws 38 to remove the two halves of the sectional ring 34 and thereafter the cap 21. The floating tube sheet 15, being of slightly smaller diameter than the inner diameter of the shell 10, may be drawn rapidly through the shell l0 if it is desired to abstract the tube bundle 13.

Instead of employing the sectional ring 34, a plurality of segmental clamps 39 may be substituted, each of these segments having one or more and preferably two of the set screws or bolts 38 and cooperating end to end to form the complete ring 34 shown in Fig. 3.` The single segment is shown in Fig. 4. This segmental clamping arrangement has all of the advantages of the sectional ring 34 described in connection with Figs. 1 and 2, and has the additional advantage of being easier to handle because of the smaller elements which make up the complete ring.

Another modified form of the clamping means is illustrated in Figs. 5 and 6. In this arrangement separate clamps 40, one for each set screw or bolt 38 and having the same cross sectional shape as the sectional ring 34 and the segments 34', are spaced equi-distantly around the periphery of the cap rim 31 and floating tube sheet 15 to clamp them squarely and securely together in the manner described in connection with the arrangements of Figs. 1 to 4, inclusive. These separate clamps 40 have all the advantages of the arrangements of Figs. 1 to 4, inclusive, and have the additional advantages of lightness and easy handling.

Although the invention has been described in connection with a two-pass heat exchanger, it is to be understood that the invention is applicable with equal facility to a single pass heat exchanger or other apparatus requiring a tightly sealed connection of this type.

I claim:

1. In a heat exchanger, the combination of a shell, a tube bundle therein, a tube sheet for one end of the tube bundle, a cap for said tube sheet having a rim engaging the outer face of the tube sheet, an element embracing the peripheries of the tube sheet and cap rim, an'd means for securing the element in this posltion. .r

2. In a heat exchanger, the combination of a shell, a tube bundle therein, a tube sheet for one end of the tube bundle, a cap for said tube sheet havin a rim engaging the outer face of the tube s eet, and an element engaging the inner face 0f the tube sheet and the outer face of the cap rim for holding the tube sheet and cap together.

3. In a heat exchanger, the combination of a shell, a tube bundle therein, a tube sheet for one end of the tube bundle, a cap for said tube sheet having a rim engaging the outer face of the tube sheet, an element engaging the inner face of the tube sheet and the outer face of the cap rim, and securing means on the element and engaging the cap for locking the tube sheet and ca together.

4. In a heat exianger, the combination of a shell, a tube bundle therein, a tube sheet for one end of the tube bundle, a cap for said tube sheet having a rim engaging the outer face of the tube sheet, and an element spanning the peripheries of the tube sheet and cap rimand engaging their opposite faces for clamping them together.

5. In a heat exchanger, the combination of ashell, a tube bundle therein, a tube sheet for one end of the tube bundle, a cap for said tube sheet having a rim engaging the outer face of the tube sheet, and an element spanning the peripheries of the tube sheet and cap rim, and means locking the element to the opposite faces of the tube sheet and cap rim.

6. In a heat exchan er, the combination of a shell, a tube bundle t erein, a tube sheet for one end of the tube bundle,y a cap for said tube sheet having a rim engaging the outer face of the tube sheet, and a clamping element of channel cross-section encircling the tube sheet and cap, the anges of the element extending radially inwardly to overlap the opposite faces of the tube sheet and cap for locking them together.

7 In a heat exchanger, the combination of a shell, a tube bundle therein, a tube sheet for one end of the tube bundle, a cap for said tube sheet having a rim engaging theouter face of the tube sheet, an element of channel crosssection embracing the peripheries of the tube sheet and acap rimand means onI the flanges of the element engaging the corresponding faces of the tube sheet and 'cap rim for clamping them together. f

8. In a heat exchan er, the combination of a shell, a tube bundle t erein, a tube sheet for one end of the tube bundle, a cap for said tube sheet having a rim engaging the outer face of the tube zsheet, and a ring of channel cross-section placed jointly over the pe- Leeeer ripheries of the `tbe sheet and cap rim and secured thereto.

9. In a heat exchanger, the combination of a shell, a tube bundle therein, a tube sheet for Aone end of the tube bundle, a cap for said tube sheet having a rim engaging the outer face of the tube sheet, said tube sheet having a groove in its inner face, an element embracing the tube sheet and cap rim and having means projecting into the groove of the tube sheet, and means o`n the element engaging the outer faceof the cap.

10. Ina heat exchanger, the combination of a shell, a tube bundle therein, a tube sheet for one end of the tube bundle, a cap for said tube sheet having a rim enga-ging the outer face of the tube sheet, said tube sheet having a groove in its inner face, an element embracing the tube sheet and cap rim, a reversely turned flange on the element engaging the groove of the tube sheet and a radial flange on the element engaging the outer face of the cap. L i

11.` In a heat exchanger, the combination of a shell, a tube bundle therein, a tube sheet for one end of the tube bundle, a cap for said tube sheet having a rim engaging the outer face of the tube sheet. said tube sheet having a groove in its inner face, an element embracing the tube sheet and cap rim, a reversely turned flange on the element engaging the groovel of the tube sheet, a radial flange on the element overlapping the Aouter face of the cap, and set screws threaded through the radial flange of the element and engaging the cap rim for drawing the tube sheet and cap together. I

12. In a, heat exchanger, the combination of a shell. a tube bundle therein. a tube sheet for one end of the tube bundle, a cap for said tube sheet having a rim engaging the outer face of the tube sheet, said tube sheet having a groove in its inner face, an element of channel cross-section placed over the peripheries of the tube sheet and rim cap, one radial iange of the element having an inwardly turned edge lying on the tube sheet groove, and a plurality of set screws threaded lthrough the other radial flange of the element and engaging the outer face of the cap rim for drawing the outer peripheries of the tube sheet and cap rim together within the channel of the element.

13. In a heat exchanger, the combination of a shell, a tube bundle therein, a tube sheet for one end of the-tube bundle, a cap for said tube sheet having a rim engagingfthe outer face of the tube sheet, and a complete ring embracing the peripheries of the tube sheet and cap rim for clamping them together.

, 14. In a heat exchanger, the combination of a shell, a tube bundle therein, a tube sheet for one end of the tube bundle, a capfor said tube sheet having a rim engaging theou'ter face of the tube sheet, and a plurality of segfor one end of the tube bundle, a cap for said tube sheet having a rim engaging the outer face of the tube sheet. and separate clamps embracing the tube sheet and cap rim and spaced around thenerinheries thereof.

In testimony whereof I aiix my signature.

OSCAR W. HEIMBERGER.

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