US1884210A - Heat exchanger - Google Patents

Description

Oct. 25, 1932. J, POTTER 1,884,210

HEAT EXCHANGER Original Filed Jan. 6. 1931 3 Sheets-Sheet l 00 00000000 00 '-.OOOOO OO=DOOOO OO O 1300 00000000000 00 OO'OO 'OOOOOOD INVENTOR John H. Potter BY mam,

ATTORNEY 3'! 2| FIG. 3.

Oct. 25, 1932. J. A. POTTER 1,334,210

' HEAT EXGHANGER Original Filed Jan. 6, 1931 3 Sheets-Sheet 2 INVENTOR John A. Potter BY we. LN/v;

ATTORNEY J. A. POTTER HEAT EXCHANGER Oct: 25, 1932.

3 Sheets-Sheet 3 INVENTOR John H. Potter Original Filed Jan. 6. 1931 BY a. 6. M

ATTORNEY Patented Oct. 25, 1932 UNITED STATES PATENT OFFICE JOHN A. POTTER, 01' 110031, PENNSYLVANIA, ASSIGII'OB 'IO WESTINGHOUSE ELEGIBIO 8: MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA BEAT CHANG-EB Application med January 6, 1981, Serial No. 507,017. Renewed June 8 1988.

'the tube bundle and which will provide for ready removal of the tubes therefrom after the apparatus'has been assembled for use.

Heretofore, the problem of removing tubes, particularly finned type tubes, from an assembled heat exchanger structure has presented difliculty. For solving this problem, I have conceived the idea of providing an arrangement which will permit the removal of the tubes from any part oi the tube bundle of a heat exchanger structure of the character designated. I provide for this by dividing or forming the tube plate, at one end of the tube bundle. into a plurality of sections each supporting a relatively narrow bank of tubes. When it is desired to remove or repair a tube, the divided tube plate is separated along one of the division lines adjacent to such tube as it is desired to repair or remove. By a slight bending of the tubes, the sections of the tube plate may be readily forced apart a suflicient amount to permit access to the tube in case of repair or to permit the tube to pass through the opening between the sections in case of removal. In the latter case, it is merely detached from the tube plate at itsends in any wellknown manner and withdrawn through the opening.

It is a still further object of my invention,

. therefore, to provide for removal of tubes fromthe tube bundle of an assembled heat exchange structure of the character designated the utilizat on of a divided tube plate atone end of the tube bundle which may be separated along the division line adjacent to a tube which it is desired to remove to provide an opening through which the tube may pass.

When a divided tube plate or a tube late comprising a plurality of sections, suc as I have described, is utilized, the ordinary unitary type of header is not adapted to form the required fluid circulatin chambers for the tubes. I, therefore, provi e a type of umtary header having means for easily attaching each of the tube plate sections thereto and means for securing an effective fluid seal between the header and the tube plate sections which will enable the header and the tube plate to function substantially in the same manner as if a unitary tube plate were used. According to my invention, the header is provided with ribs and side walls, which en age the boundaries of each section of the tu plate so as to provide a compartment corresponding to each tube plate section. Any desired travel of fluid through the tubes is provided by joining comartments by openings formed in the ribs tween adjacent compartments.

A still further object of my invention, therefore, is to provide a unitar cover or header member cooperating with the sections of the divided tube plate, in such a manner as to secure adequate fluid seal between the header and the tube plate sections and to provide for the desired fluid flow through the header and the tubes.

Still another object of my invention is to provide in heat exchanger apparatus of the character designated an arrangement for obtai'ning a plurality of passes of the fluid circulating through the tube bundle which is capable of being modified to provide any desired number of passes of fluidthrough the tube bundle, such modification being accomplished with a minimum number of alterations of the parts.

By the application of a type of construction similar to that already outlined to both ends of the tube bundle or the heat exchanger structure, it will be evident that the tube bundle may be arranged to com rise a plurality of inde ndent tube bun 10 units or tube banks w ich may be assembled with unitary headers at both ends to form the heat exchange tube bundle assembly. Forming the tube bundle of a plurality of independent tube bundle units makes possible standardiza tion of design with consequent lower production costs. Moreover, any suitable number of units may be assembled with headers of suitable size to form the tube bundle for any desired size of heat exchanger.

Still another object of my invention is, therefore, to provide a heat exchanger tube bundle assembly embodying a plurality of independent tube bundle units or banks secured together by the attachment of a unitary header of suitable size to the respective tube plate sections at opposite ends of the assembly.

These and other objects are effected by my invention, as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is a plan view of one embodiment of my invention, showing a heat exchange unit in position in the shell structure;

Fig. 2 is a View, in side elevation, of the embodiment shown in Fig. 1;

Fig. 3 is a cross-sectional view taken along the line IIIIII of Fig. 2 showing the sectionalized end tube sheet and its position with respect to the surrounding shell structure;

Fig. 4 is a view, in sectional elevation, of the unit removed from the shell structure and showing details of the headers;

Fig. 5 is a view, in sectional elevation, of a modified form of heat exchange unit showing the relative arrangement of the headers and tube plates; and,

Fig. 6 is a view, in sectional elevation, showing a heat exchange unit similar to that shown in Fig. 4 with the parts disassembled and the sectionalized tube sheet separated along one of the division lines for the removal of a tube from the tube bundle.

Referring to the drawings, I illustrate a type of heat exchanger particularly adapted to cool or heat a stream of air or other gaseous media flowing transversely through the shell structure externally of the tubes. The shell structure 10, as illustrated in Figs. 1 to 3, has a tube bundle assembly 11 having suitable dimensions for permitting it to be inserted through the open end 12 into the shell structure and removably secured therein. The shell structure is preferably open at the top and bottom but enclosed on three of its sides by rectangularly-disposed side walls 13, 14 and 15. The remaining side of the shell structure is closed by a portion of the tube bundle assembly 11. As installed, the heat exchanger is disposed transversely of the duct through which the air to be heated or cooled flows.

The tube bundle assembly embodies a series of banks or tube bundle units 16 embodying tubes which may be of the finned type. The tubes of all of the banks are fixedly supported at one end in a unitary tube plate 17 which, in turn, is removably secured to the open end 12 of the shell structure, while, at the other end, the tubes are fixedly secured to a sectionalized floating tube plate 18. The floating tube plate 18 is composed of a plurality of similar and independent tube plate sections 19, preferably, of a relatively narrow, elongated form, into which the tubes of each of the banks 16 are, respectively, secured. The floating tube plate is carried on suitable cross members 21 forming a part of the shell structure.

As illustrated in Figs. 4 and 6, a header or cover member 22 is provided to cooperate with the unitary tube plate 17 for circulating fluid through the tubes. This header member comprises an intermediate section 23 and a cover plate 24 secured to the outer face of the intermediate section. The intermediate section 28 contains an inlet opening 25 and an outlet opening 26, and in addition, a series of transversely-disposed partitions 27 which, as will be presently explained, serve to form such a number of compartments 28 as is required to provide the desired fluid flow. Bolts 29 secure the parts of the header 22 together and secure the header to the tube plate 17 and may also serve to attach the tube bundle, when in assembled position, to the shell structure.

At the other end of the tube bundle 11, a header member 31 is provided to cooperate with the sections 19 of the tube plate 18 to form chambers 32 which return or redirect the fluid through the tubes. The header member 31 is common to all the tube plate sections 19 and embodies ribs 33 and side walls 34 adapted to engage around the entire margin 35 of the outer face of each section. The ribs 33 span the joints between the tube plate sections 19 and thus seal the sections together so that, in effect, the tube plate 18 is a unitary tube plate and thus may as effectively perform the function of a floating tube )late as if it were actually made in one piece.

acking material (not illustrated) of any well-known type may be inserted between the engaging ribs and the side walls of the header member 31 and the face of the tube plate sections 19 so as to secure more readily a fluidtight seal therebetween. As can be seen, the tubes 16 are arranged to occupy the greater portion of the surface of each of the sections 19 of the sectionalized plate so that only a relatively narrow marginal portion 35 remains free of the tubes to provide the surface which may be engaged by the header member 31 to form the seal. However, this relatively narrow margin will form adequate engaging surface because means is provided for securing each of the tube plate sections 19 to the header 31 which will leave the margin imperforate and free of any bolts or other obstructions. The means for securing the header and the plate sections together is provided by bolts 36 which pass through the portion of the header lying intermediate of the ribs and side walls into tap ed holes 37 located substantially centrally of the portion of the tube plate sections occupied by the tubes. In this manner, an effective sealing surface is provided between each of the sections of the tube plate 18 and the header 31 while, at the same time, a maximum amount of surface remains for the distribution of holes in which tubes may be secured. While the header member 31 is shown as one-piece, it may be constructed, with the omission of the inlet and outlet openings, substantially as the header member 22 used in connection with the unitary tube plate 17 at the other end of the tube bundle.

, After heat exchangers of the type to which my invention relates have been put in service, it sometimes happens that one or more tubes of the tube bundle become damaged by corrosion, or otherwise, which causes them to leak and makes it desirable to renew or repair the same.

Heat exchangers constructed according to my invention have the advantage of providmg ready access to any of the tubes for the purposes of repair or removal. When the condition of a tube is such as to make the removal thereof desirable, it may be accomplishes substantially in the manner illustratd in Fig. 6. The header at the return end of the tube bundle 11, which comprises header member 31 and a sectionalized tube plate 18, has dimensions sufiiciently less than the inside of the shell structure 10 to permit it to pass longitudinally therethrough. The tube bundle is removed from the shell structure by removing the bolts which attach the tube plate 17 to the open end 12 of the shell structure 10 and withdrawing the tube bundle 11 longitudinall through the open end 12. After removal 0 the tube bundle, the header member 31 is detached from the sectionalized tube plate 18 and the header member 22 associated with the unitary tube plate 17, or

'merely the outer wall plate 24 thereon, is removed. Both ends of all of the tubes being thus exposed to view at the outer face of the tube lates 17 and 18, the defective tube can now e readily located. Having determined which tube is to be removed, any well known means may be employed to disengage the tube ateach end from the end tube plates. Then, if the tube is located in either one of the inner tube banks or the inner side of either of the outer tube banks, as for example, tube 16', Fig. 6 the division line in the sectionalized tube plate 18 adjacent the detached tube is located and the tube plate sections 19 are forced apart, by any suitable'means, along this division line, causing the tubes in the plate sections on opposite sides of the division line to be flexed away from each other to form an opening suflicient to permit the tube to be withdrawn, longitudinally, from the tube bundle. The spreading apart of the section 19 of the sectionalized tube plate 18 by flexing of the tubes is readily accomplished because the tubes are ordinarily relatively long and slender.

In cases where it is desired to remove or replace any one"of the tubes without involving bendin or flexure of most of the tubes, this can e readily accomplished by providing a structure such as shown in Fig. 5 wherein the sectionalized tube sheets, instead of being provided at only one end of the tube nest, are provided at both ends. Referring now to Fig. 5, I show a tube bundle assembly comprising a plurality of independent tube banks or units 16". The tubes in each bank or unit are secured at both ends in indpendent tube plate sections 19, the latter having associated therewith, respectively, common header members 22 and 31 at the ends thereof forming the heat exchanger tube bundle assembly 11'. p

When it is desired to remove a tube from the tube bundle in this embodiment, the header members 22 and 31 are removed, permitting any one of the tube banks 16" to be withdrawn, as a single assembly from the tube bundle. \Vith this 'form of construction, no bending or flexure of the remaining tubes is required. Having removed one of the tube banks from the tube bundle, the defective tube or tubes therein may be replaced or, if desired, an entire new tube bank may be replaced in the tube bundle.

In the embodiment illustrated in Fig. 5, the return header cooperating with the floating tube plate 18. is substantially the same as in the embodiment already described and illustrated in Figs. 1 to 4. However, the fluid supply header member22' at the fixed end of the tube bundle is modified to enable the transverse partitions 27 to perform the same function as the engaging ribs 33 of the common header member 31 at the floating end of the tube bundle. In other words, the transverse partitions 27 provided in the header member 22 span the joint between the sections 19 of the sectionalized tube plate 20 and with the header side walls, forms a boundary line of sealing engagement with a marginal portion of the outer face of each comprise a plurality of independent tube bundle units 16" of similar design, which are uniform and interchangeable and which may be manufactured in quantities with consequent lower production costs. Moreover,

any suitable number of units may be assembled with headers of suitable size to form the tube bundle for a heat exchanger having any desired capacity. In addition, in cases where replacement of a large number of tubes in one bank should become necessary, a replacement of the entire tube bank is made practical and economical.

In actual service, the conditions of the water or other fluid circulated through the tubes of the tube bundle may differ widely, particularly as to quantity and temperature. The effective use of the circulating fluid is governed by the number of passes through the tube bundle which the fluid makes in flowing from the inlet to the discharge in the fluid supply header. For this reason, the number of passes in one heat exchanger in stallation may differ from that required in another heat exchanger installation of substantially the same capacity.

In heat exchangers constructed according to my invention, the number of passes of the fluid through the tube bundle may be varied without making any material changes in design and construction. By referring to the drawings, it will be observed that, in each of Figs. 4, 5, and 6, I have illustrated different numbers of passes. In Fig. 4, I have illustrated what might be termed a serial pass arrangement, that is, the coolin water flows, as indicated by the arrows, serially through the consecutive rows of tubes in the tube bundle 11 from the inlet to the discharge side of the header 22. In Fig. 5, I have illustrated an arrangement in which the flow is in multiple series, that is, the flow, as indicated by the arrows, is serially through multiples of two tube rows. Or in other words, the cooling water flows from the inlet opening 25 in the header 22' forward in the lower two adjacent rows of tubes 16 of the tube bundle 11 and returns in next higher two adjacent rows 16' proceeding in this manner serially through the whole tube group to the discharge opening 26. In Fig. 6, I have illustrated another multiple series arrangement in which the cooling water makes only two passes in flowing from the inlet to the outlet opening, that is, it flows from the inlet 25 forward in the lower half of the tube group 11 in a multiple of four tubes and serially into another multiple of four tubes in the upper half through which it returns to the outlet 26.

It will be observed that, primarily, as far as relating to fluid flow, the only essential difference in the arrangement illustrated, in the several figures referredto, is the location of the transverse bafiles 27 in the fluid supply headers, or the location of openings in the bafiles 27 as the case may be, and the location of the openings 38 in the transverse ribs 33 of the header at the fluid return end of the tubes. In other words, when it is desired, in manufacturing apparatus of this character, to change from a single series flow arrangement, or arrangement giving the maximum number of passes, to any other arrangement giving a lesser number of passes, the structure is such that it can be readily modified by providing suitable openings 38 in the ribs 33 of the fluid return header 31 and likewise suitable openings in the transverse partitions 27 of the fluid supply headers 22. For example, changing the type of tube bundle illustrated in Fig. +1 from the number of passes shown in the drawings to an arrangement for two passes similar to that shown in Fig. 6, may be accomplished by providing openings in the transverse partitions 27 which are nearest the fluid inlet and outlet openings 25 and 26 in the supply header 22 and also by providing openings in the ribs 33 of ,the return header. In this way, the fluid flowing through the inlet opening 25 enters the three lower rows of tubes and passes through the return header to the three upper rows of tubes and thence to the outlet. The arrangements illustrated in the other figures may be similarly modified in the manner described.

While I have shown my invention as embodied in a type of heat exchange structure adapted to certain special uses, it is to be understood that my invention is not limited to any one type of heat exchanger and, while I have illustrated my invention as embodying finned type tubes, it is to be understood that it is equally applicable to heat exchangers using other types of tubes.

While I have shown my invention in several forms, it will be obvious to those skilled in the art that it is not so limited, but'is susceptible of various other changes and modifications, without departing from the. spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. A heat transfer unit for a heat exchanger comprising, in combination, a plurality oftube bundle units, each embodying a tube plate section and a series of tubes secured at one end in the said tube plate section, a common box structure cooperating with all of said sections to form a fluid conveying chamher for the tubes, and means for separately securing each of the tube plate sections to said box structure.

2. In a heat exchanger, the combination of a shell structure, a tube bundle disposed within said shell structure, a tube plate in which one end of each of the tubes is secured, said tube plate comprising a plurality of separate sections, a common box structure fitting against the marginsof the outer faces of all of said sections, and means engaging each section at a point removed from the margin for se arately securing each of the sections to the ox structure.

3. In a heat transfer unit for a heat excha r, the combination of a tube bundle embo ying a lurality of tube units, a tube plate section or each tube unit in which an end of the tubes is secured, a common box said box structure member an structure cooperating with said tube plate sections to form fluid conveying chambers for the tubes, means provided'on the box structure for en aging the margin of the outer face of each section, said engaging means forming a perimetrical fluid sealing contact therewith, and means engaging an interior portion of each of the tube plate sections for separately clamping the same to the box structure.

4. The combination in a heat exchanger, of a shell, a tube bundle removable as a complete assembly from the shell, said tube bundle comprising a plurality of tube bundle units each embodying a tube plate section and a series of tubes secured at one end in said tube late section, said sections being assembled in a common plane, a common box structure member fitting against the outer marginal faces of each of the tube plate sections and cooperating therewith to form fluid-conveying chambers for the tubes, and means secured to each of the tube plate sections for separately attaching the same to the box structure.

5. The combination in a heat exchanger, of a shell structure and a heat transfer assembly removable therefrom, said heat transfer assembly comprising a plurality of tube bundle units each embodying a tube plate section and a series of tubes secured at one end in the tube plate section, said sections being disposed adjacent to each other in a single plane when in assembled position, a common box structure member cooperating with said sections to form fluid-tight, fluid-conveying chambers for the tubes, said box structure member including sealing ribs and side walls cooperating to engage the joints between ad acent tube plate sections as well as the outer margin of the assembled tube plate sections, and a series of bolts extending throu h portions of g spaced from the ribs and side walls and engaging each of the tube plate sections for separately securing the same to the box structure member.

6. The combination in a heat exchanger, of

' a shell structure and a heat transfer assembly the plate sections so as to leave an imperforate marginal portion and said sections being assembled adjacent to each other in a common plane, a common cover member cooperating with said sections to form fluid-tight, fluidconveying chambers for the tubes, said cover member including sealing ribs and side walls cooperating to span the joints between adjacent tube platewsections and to engage the marginal portions of each of said sections, and means engaging the tube plate sections at a point remote from their marginal portions for separately clamping each of said sections to the cover member.

7. In a heat exchanger, the combination of a shell structure, a series of tubes disposed within the shell structure, a header in dommunication with one end of the tubes and including a unitary tube plate in which one end of the tubes are secured, a second header in communication with the other end of the tubes, said second header embodying a tube plate divided into a plurality of separate sec, tions in which the other ends of the tubes are secured and a common box structure engaging the sections of the latter tube plate, and means for securing separate fluid-tight engagement of each of the tube plate sections with said common box structure.

8. In a heat exchan er, the combination of a shell structure an a heat transfer unit disposed within the shell structure, said heat transfer unit comprising spaced header members, a plurality of tube plate sections separately secured to one of the header members, a corresponding number of tube plate sections secured in like manner to the other header member, and a series of tubes extending between corresponding pairs of tube plate sections, said headers and tube plate sections cooperating to form fluid-conveying and distributing chambers for the tubes.

9. The method of removing a detached tube from the interior of a heat exchanger tube bundle having a unitary tube plate at one end and a sectionalized tube plate at the other end, which comprises forcing apart the sections of the sectionalized tube late adjacent to the detached tube so as to orm an opening between the sections suflicient for the tube to pass through, and withdrawing the detached tube through said openin 10. The method of removing a tube rom a heatexchanger tube bundle having tube plates, one of which is divided into sections and also having a box structure secured to the sectional tube plate, which comprises detaching the tube at itsends from the tube plates, removing the common box structure from the sectional tube plate, forming a suitable opening along a division line nearest the tube to be removed b forcing sections of the tube plate apart, an withdrawing the detached tube through said opening.

11. The method of removing a tube from a heat exchanger tube bundle having tube plates one of which is divided into sections and also having a common box structure secured to the sections of the sectional tube plate to be removed by forcing adjacent sections of the tube plate apart and by deflecting the tubes connected thereto, and withdrawing the detached tube through said opening.

12. In a heat exchanger, the combination of a shell structure, a tube bundle disposed in the shell structure and comprising spaced tube plates and a series of tubes extending therebetween, detachable header members abutting the tube plates and arranged to provide, in cooperation therewith, fluid circulation chambers for directing fluid through the tube bundle in a plurality of passes, said header members being ada ted to be replaced by other header mem rs to vary the number of passes of the fluid through the tube bundle.

13. In heat exchange apparatus, the combination of a shell structure, a tube bundle dis osed within the shell structure and embo ying a series of similar and interchangeable tube bundle units, each of said units comprising spaced tube sheet sections and a plurality of tubes secured to and extending between said sections and said tube bundle units being assembled in side-by-side relation and havin their adjacent tube sheet sections disposed in common planes, a header member for each end of all of the tube bundle units, and means for detachably securing the header members to their adjacent tube sheet sections and providing for removal of any one of the tube bundle units from the tube bundle.

In testimony whereof, I have hereunto subscribed my name this 5th day of J an- (Seal) uary, 1931.

JOHN A. POTTER.

CERTIFICATE OF CORRECTION.

Patent No. 1,884,210. October 25, 1932.

JOHN A, POTTER,

ll is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, line 26, claim 4, and lines 42, 44, 50 and 53. claim 5, strike out the word "member", and line 117, claim 10, before "him" insert the word "common"; and that the said Letters Patent should he read with these corrections therein that the same may con form to the record of the case in the Patent Office.

Signed and sealed this 25th day of April, A. D. 1933.

M Acting Commissioner Jf Patents.

plate to be removed by forcing adjacent sections of the tube plate apart and by deflecting the tubes connected thereto, and withdrawing the detached tube through said opening.

12. In a heat exchanger, the combination of a shell structure, a tube bundle disposed in the shell structure and comprising spaced tube plates and a series of tubes extending therebetween, detachable header members abutting the tube plates and arranged to provide, in cooperation therewith, fluid circulation chambers for directing fluid through the tube bundle in a plurality of passes, said header members being ada ted to be replaced by other header mem rs to vary the number of passes of the fluid through the tube bundle.

13. In heat exchange apparatus, the combination of a shell structure, a tube bundle dis osed within the shell structure and embo ying a series of similar and interchangeable tube bundle units, each of said units comprising spaced tube sheet sections and a plurality of tubes secured to and extending between said sections and said tube bundle units being assembled in side-by-side relation and havin their adjacent tube sheet sections disposed in common planes, a header member for each end of all of the tube bundle units, and means for detachably securing the header members to their adjacent tube sheet sections and providing for removal of any one of the tube bundle units from the tube bundle.

In testimony whereof, I have hereunto subscribed my name this 5th day of J an- (Seal) uary, 1931.

JOHN A. POTTER.

CERTIFICATE OF CORRECTION.

Patent No. 1,884,210. October 25, 1932.

JOHN A, POTTER,

ll is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, line 26, claim 4, and lines 42, 44, 50 and 53. claim 5, strike out the word "member", and line 117, claim 10, before "him" insert the word "common"; and that the said Letters Patent should he read with these corrections therein that the same may con form to the record of the case in the Patent Office.

Signed and sealed this 25th day of April, A. D. 1933.

M Acting Commissioner Jf Patents.

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