US2207037A

US2207037A - Heat exchanger

Info

Publication number: US2207037A
Application number: US335921A
Authority: US
Inventors: George T Jacocks
Original assignee: Lummus Co
Current assignee: CB&I Technology Inc
Priority date: 1937-11-13
Filing date: 1940-05-18
Publication date: 1940-07-09
Anticipated expiration: 1957-07-09

Description

G. T. JACOCKS 2,207,037

HEAT ExemmeER July 9,1940;

Original Fil ed Nov. 13, 1937 2 Sheets-Sheet 1 IN VENTOR 660W8 12/440022;

Patented July 9, 194

HEAT EXCHANGER George T. Jacocks, New Rochelle, N. Y., assignor to The Lummus Company, New York, N. Y., a corporation of Delaware Original application November 13, 1937, Serial No. 174,330. Divided and this application May 18, 1940, Serial No. 335,921

This invention relates to improvements in heat exchangers, more particularly of the fluid type in which one fluid is normally conducted through the interior of a series of tubes and another fluid, in heat exchange relation, is maintained in contact with the exterior of the tubes.

One of the principal objects of my invention is to provide a heat exchanger, the tube bundle of which has a bundle wrapper, so that more intimate contact and more effective control can be had between the external fluids and internal fluids in heat exchange relation, the tube bundle being removable from the shell for inspection and cleaning.

Another object of my invention is to provide internal retractable connections for the nozzle of a heat exchanger so that the connections may be broken between the nozzle and channel or nozzle and bundle wrapper without breaking any external pipe connections.

Further objects and advantages of my invention will appear from the following description of preferred forms of embodiment thereof, taken in connection with the attached drawings illustrative thereof, and in which:

Fig. 1 is an elevation of a heat exchanger with parts broken away and shown in section;

Fig; 2 is an enlarged vertical section of the retractable nozzle for the channel end of the heat exchanger;

Figs. 3 and 4 are' similar vertical sections showing the modified forms of channel construc-v tion.

In accordance with one form of embodiment of my invention, the heat exchanger generally shown in Fig, 1 consists primarily of a shell ll! of substantially constant diameter or cross sectionv from end to end, which is reinforced at the channel end by skirt H, such shell being sealed at the open end by the cover 12 and at the other end by the fixed tube sheet Id. The tube shee; l i'supports the tube bundle generally indicated at l5, such tube bundle including a plurality of tubes suitably expanded within the fixed tube sheet l4 and extending to the floating tube sheet It, as is well-known. The floating tube sheet I6 is provided with a channel spacing member I! and a floating tube sheet cover l8 which, being spaced from the floating tube sheet l6, provides dClaim's. (on. 257-225) by a channel cover 23 and this is preferably detachable for inspection purposes. The intermediate pass bafile 2t, which distributes the circulating fluids-into and out of the tubes, may be integral with or detachable from the channel 2|. It will be apparent with the arrangement as shown that the heat exchanger is of two-pass type on the tube side, although any other arrangement could be made by varying the position and numbers of channel baiile 2d and the form of the channel spacing member ll.

A multiple number of passes on the shell side with 'a continuous floating. tube sheet 56 is also possible by using a bundle wrapper 21 which is adapted to closely embrace the tube bundle l5, such bundle wrapper engaging shoulders on the fixed tube sheet It and the floating tube sheet It. The bundle wrapper is preferably a continuous sheet of metal having a lap joint 28. The multiple pass is established by a plurality of longitudinally extending bafiies 30 of relatively thin metal placed between the tube rows. In ad dition, a plurality of lateral baffles 32 are provided and these may be of half-moon or other desired configuration. Without going into the formed for a positive and permanent tensionresisting seal. The seal is permanent and, as the straps are relatively thin, no interference occurs with the shell when the bundle is withdrawn. A plurality of straps are generally used and one is conveniently provided at the attachment to the tube sheets as well as at the respective lateral baiiles 32 so that seepage between the lateral baffles and the bundle wrapper 21 is substantially eliminated. It is, 'of course, to be understood that although other means for securing the bundle wrapper can be used, the deformed strap.

seal permits materially reduced space between the tube bundle and shell with a resulting increase in tube bundle size for any predetermined size of shell.

The sealing of the respective cover member,

channel, and tube sheet members to the shell is preferably accomplished by a trusto-conical form of gasket heretofore described in a copending application of the present inventor, filed November 3, 1937, Serial No. 172,567. These gaskets, indicated at 50, are provided between the cover I2 and the ring 5|, which is secured to the shell lflybetween the fixed tube sheet I4 and the shell III; and between the channel member 2I and fixed tube sheet I4 and channel cover 23; and between the floating tube sheet cover I8 and the skirt extension 56 on the floating tube sheet I6. Each of the respective members has complementary shoulders with relatively rounded corners in which the gasket forms a seal due to the relative change of its angular relation, which change causes a tightening of the gasket on the edges. When the parts are moved to a closed position by a series of adjustable. screws 52, which are preferably carried by a sectional bull ring 53, interlocked at 54 to a projection of the shell I0 or of the portion II, or of the portion 56, the gasket turns to a sealing position.

This sealing movement maybe in the range of' from approximately to or less when unsealed to a sealed condition. of approximately 20 to 16. The relative angularity required can be determined by the amount of tolerance provided and it is based on the major diameter of the gasket itself, the total movement being the difierence between the cosines of the angle. As

the seal is provided between the respective shoulders against which the gasket cooperates, a secondary seal can be provided between the cover I8 and the channel member I1 and between the channel member I1 and the floating tube sheet I6 as by fiat

gaskets

51 and 58, such gaskets preventing any possible'erosion of the metal.

It will be noted that the three frusto-conical gaskets at the channel end are each held in position by a single series of adjustable screws 52, which is possible without excessive size screws as the'sealing pressure -of the gaskets is independentof the pressure that holds the cover,'

channel, and floating tube sheet to the shell. The toggle action of the gaskets gives a relatively high mechanical advantage, which increases as the gasket is moved to its sealed position.

The gaskets are preferably somewhat softer than the shoulders with which they cooperate so that there 'will be some flow of metal and all crevices will be filled. The gaskets, however, are

preferably of a resilient metal so that they will continuously maintain a seal and, when the pressure is. relieved, they will tend to return to their original shape.

Removal of the tube bundle I5, without breakby the saddle ring 35, is movable into contact with the bundle wrapper 2'I' surrounding the opening 21a. The seal. is maintained by the pressure screws 13, which force the gasket I5 into contact with the saddle ring 35 and the gasket I6 into contact with the bundle wrapper. The jackscrews 8| are alternated with the presor 4. In Fig. 3 the shell 90 has the pipe nozzles 9I sure screws I3 so that the retractable coupling I0 may be withdrawn. Both the Jackscrews BI and the pressure screws 13 are provided with

caps

82 and 83 to prevent leakage. I

Retractable connections are also provided for the channel connections and they may be used to great advantage irrespective of the use of a bundle wrapper, although they] are especially valuable therewith. As more particularly shown in Fig. 2, the channel 2I is wholly. within the shelland the shell is provided with fixed nozzles 22. This nozzle has a movable sleeve I58 which is provided with suitable shoulders for cooperative relation with gaskets I59 and I60. These gaskets engage shoulders on the fixed nozzle 22 and the channel 2| respectively.

Movement of the retractable sleeve'l58 is ac-' complished by screws I62 in screw threaded engagement with the interior of the fixed nozzle 22 and in abutting relation with the sleeve I58 and being adapted to engage shoulders I58a to force the sleeve into sealed position and adapted to engage shoulders I56b to retract the sleeve. In the retracted-position of the sleeve, the channel and tube bundle may be completely withdrawn from the shell. Retraction is accompl'ished from the exterior of the shell by the screws I62, which extend through the pipe flange I63, and no pipe connections need be broken for this purpose.

Removal of the tube bundle without destroying the external nozzle connections to the channel can also be accomplished by using either of the retractable forms of connection shown in Fig. 3

and the fixed tube sheet 96 by the pressure screws generally indicated at 52 and the bull ring 53. As in the prior construction, the channel 94 is sealed with respect to the cover .95 and the fixed tube sheet 96 by a plurality of gaskets 5|] of the frusto-conical type.

The nozzle 9I is. sealed with respect .to the channel 94 by a retractable sleeve or collar 98 which is held against the nozzle by the screws 99. The parts are sealed together by a plurality of gaskets which. may also be of the frustoconical type 91, certain of which are between the channel 94 and the collar 98 and certain of which 7 are between the collar 98 and the nozzle 9|. By

the usev of the frusto-conical gaskets, it is possible to simultaneously seal the retractable member with respect to the channel and nozzle inasmuch as the gaskets commence to seal as soon as they rotate, and the seal is increased in effectiveness as the parts are drawn together. i

In Fig. 4 the shell III! is provided with a detachable nozzle III held by the screws II2. As

in the prior form, the nozzle III is made pressure-tight with respect to the channel II4 by a form of frusto-conical gasket II3 which, in this case, engages a shoulder on the nozzle I I I and a shoulder on the channel I I4. By tightening up on the screws I I2, the gasket will be rotated iii-toggle fashion to set up the desired seal. The channel H4 is secured to the fixed tube sheet H6 and cover II9 by the screws 52 and bull ring 53.

The jackscrews I20 can be used to partially retract the nozzle III and, when retracted a sufficient distance, the channel will clear the end of the nozzle. A suitable retaining member in the form of a wire I2I is provided to assist in positively withdrawing the gasket H3 to break the seal.

In each of these forms, external pipe connections need not be broken in order to remove the tube bundle as in Fig. 3. The connection is broken within the shell by a retractable member, and in Fig. 4, the small amount of retraction necessary for the pipe connection Ill can be accomplished by the jackscrews.

It will thus be apparent that the heat exchanger can be provided with a removable tube bundle which can be removed from the shell without breaking external pipe connections. This is irrespective of whether it be provided with a bundle wrapper. In each case, the entire channel is efiectively sealed within the shell but without any reduction of efiective tube area as the floating tube sheet can be almost as large as the shell. All external flanges are eliminated and by using the bundle wrapper a more eflective confinement of the fluids about the tubes is accomplished.

This application is a division of my copending application Serial No. 174,330, filed November 13, 1937.

While I have shown preferred forms of embodiment of my invention, I am'aware that other modifications may be made thereto and I, therefore, desire a broad interpretation of my invention within the scope and spirit of the description herein and of the claims appended hereinafter.

I claim:

1. In a heat exchanger, a shell, fluid nozzles secured thereto, a removable tube bundle assembly including a fixed tube sheet, a channel and a channel cover, means to connect the tube bundle to the fluid nozzles, said means including a retractable coupling between the nozzles and the channel.

2. In a heat exchanger, a shell, external pipe connections secured thereto, a removable tube bundle assembly including a fixed tube sheet, a channel and channel cover, means to connect the channel and external pipe connections including" a retractable coupling between the pipe connec- 3. In a heat exchanger, a shell, external pipe connections secured thereto, a removable tube bundle assembly including a fixed tube sheet, a channel and channel cover, means to connect the channel and external pipe connections including a retractable coupling between the pipe connections and the channel, and gasket means to seal the coupling with respect to the pipe connection, and means to retract the coupling to break the connection between the channel and nozzle, said means including means operable from the exterior of the shell.

4. In a heat exchanger, a shell, a fixed pipe connection integral-with the shell, a removable tube bundle assembly having a header channel and means to interconnect the pipe connection and the header channel including a retractable coupling, said retractable coupling having sealing gaskets engaging the channel and other sealing gaskets engaging the fixed pipe coupling, and means to draw down said retractable coupling on both of said gaskets to simultaneously seal the parts.

5. In a heat exchanger of the class described,

6. In a heat exchanger of the class described,

a shell, a tube bundle assembly therein including a tube bundle, a channel and a channel cover. a wrapper for said tube bundle, fluid nozzles connected to said shell, connections between said nozzles and said bundle wrapper and said tube bundle assembly, respectively, said connections comprising internally retractable members wherebysaid tube bundle may be withdrawn from the shell without breaking external connections to the nozzles.

GEORGE T. JACOCKS.