US1967781A

US1967781A - Heat exchange apparatus

Info

Publication number: US1967781A
Application number: US666580A
Authority: US
Inventors: John A Petter; John P Rathbun
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1933-04-17
Filing date: 1933-04-17
Publication date: 1934-07-24
Anticipated expiration: 1951-07-24

Description

July 24%-, 1934. J. A. POTTER ET AL HEAT EXCHANGE APPARATUS Filed April 17, 1953 5 SheeS-Sheei l @nu SAMS M RTH O T R .HTQ .O @im me?. a WN H @O JJM wlTNEssEs:

July 24,-` 1934- J'. A.. POTTER Er Ar. 1,967,781

HEAT EXCHANGE APPARATUS Filed April 17,71935 3 Sheets-Sheet 2 "nulli" INVAENTOR Jol-N .PoTTL-:rf,& JOHN P. RQTHBUN. N' BY @GLM ATTORNEY Juiy 24, 1934., J. A. POTTER ET AL HEAT EXCHANGE APPARATUS Filed vApril 17, 1933 3 Sheets-Sheet 3 I :lill-lill o o O wlw/f o o s @we UHT @o OO 8: e HN P. Env-Haw.

WITNEss'Es; m

Patented july 24, 1934 STATES PATENT OFFICE r .rr EXCHANGE are TUS Application April 17,7 1933, Serial No. 666,580

9 Claims.

Our invention relates to surface type heatexchange apparatus and it has for abroad subject to provide apparatus of this character which is of improved form and construction.

Apparatus oi this character heretofore known to us usually comprises a tubular shell; a longitudinally-disposed nest of tubes in the shell; and a header construction at each endof the tube nest; each header including a tube sheet vhaving l@ holes therethrough for receiving the ends of the tubes, a tubular body secured at one end to the tube sheet and a closure for the other end of the body. l h

Apparatus o this character is used to transfer l5 heat from one uid to another fluid, one uid iiowing through the headers and the inside of the tubes, and the other uid iiowing through the shell and contacting with the exterior of the tubes. The heat exchanger may be either single pass or multiple pass, i. e., fluid may be caused to iiow from one header and in one direction through all of the tubes to the other header, or

the iiuid may now from one header through a portion of the tubes vto the other header and Y thence back through another portion of the tubes f to the iirst header. Partitions are provided in the headers of multiple-pass heat exchangers to efrect the desired character of ow of the iluld through the tubes. Also, if desired, either longi- 3U-tudinal or vertical baiiles or both may be provided in the shell toy eiect any desired path of ow from the medium contacting with the exterior of the tubes.

The present invention has to do particularly with heat exchangers wherein one or both'of the uids is under very high pressures, for example, a thousand pounds per square inch. In cases where only one of the fluids is under high pressure, that fluid is usually passed through the l-tubes, because it is cheaper to build a header construction to withstand a given high pressure than it is to construct a shell for such purpose. In all headers, it is necessary to provide a removable end closure, so that the tubes may be 45. cleaned or replaced. In prior types of high-pressure headers, end covers have been bolted to flanges provided on the outer end of the tubular body. However, considerable difiiculty has been experienced with this construction due to the 5W size of the anges and bolts required to effect a seal against the high pressures of the uid, and due to the diculty in drawing the bolts down sufrlciently tight to eect the seal and due to the difficulty in removing the bolts. lit has been proposed heretofore to eliminate ltaken on the line lI--I of Fig. 2;

the large flanges and bolts by providing a selil sealing closure somewhat like a man hole cover. An elliptical opening is provided in the end of the header and an elliptical cover is provided having larger major and minor axes than the 6G corresponding axes of the opening but having a smaller minor axis than the major axis ofthe opening. In assembling, the cover is turned endwise with its minor axis parallel to the major axis of the opening and in this lrelative position 05: is inserted through the opening and then turned so that the corresponding axes of the cover and opening are parallel, and the cover is then drawn against the inside surface of the periphery of the opening with the peripheral surface of one side 'lil l thereof engaging the surface of the cover about' the opening and thereby eecting a complete closure of the opening. The pressure of the huid within the shell will force the cover against the end and more eectively seal the opening. This type of construction, while it eliminates the necessity of large anges, and bolts and provides an eective closure, has the disadvantage of necessitating a relatively long tubular end tov provide I fj; turning clearance for the elliptical cover plate in 89. assembling. This construction also oii'ers serious difficulties in installing transverse partitions in the header which as explained above are required in multiple-pass heat-exchangers.

The present invention has for an object to pro- 8d vide a new andl useful high pressure header con struction for heat exchangers which eliminates the necessity for large bolts and flanges; one which is Aself-sealing; one wherein ready access may be had to the tubes; and one wherein partitions may be readily installed in the tubular end.

These and other objects are eiected by our invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of 05 this application, in which:

Fig. 1 is a longitudinal vertical section showing heat-exchange apparatus constructed in accordance with thepresent invention, the section being Fig. 2 is an end view of the apparatus shown vin Fig. l;

Fig. 3 is an enlarged fragmentary vertical sec- 'tion showing more clearly the construction o! my improved high pressure header'construction; 105

Fig. 4f is a detail view showing the -end con-3 struction with'the cover plates omitted;

Fig. 5 is a detail view of one of the cover plates; Fig. 6 is a detail view of the spider-like holding means for thecover plates; no

ion-

Fig. 7 is a view similar to Fig. 3 but on a smaller scale showing the manner of assembling the tubular body and end construction;

Fig. 8 is a view similar to Fig. 2 illustrating the manner of inserting the coverplate; and,

Fig. 9 is a detail sectional view similar to Fig.

v7 butillustrating a. modied form of header construction.

Referring now in detail to the construction illustrated, the reference numeral 10 indicates a tubular heat exchanger of the two-pass type, which comprises a cylindrical shell 11 closed at one end by a removable end cover 12 and closed at the other end by a header construction 13 bolted to a. flange 14 carried by that end of the shell. A second header construction l5 is disposed in the closed end of the shell, and a plurality of uid circulating tubes 16 extend longitudinally of the shell and connect the headers 13 and 15, the ends of the tubes extending through and secured within openings provided in the headers in a manner well understood to those skilled in the art. Longitudinal movement of the header is not conned by the shell, the

header 15 only being connected to the tubes 16.

' The purpose of this is to permit relative expansion `of the tubes and shell and to permit withdrawal of the tubes and header through the shell for cleaning.

The header structure 13 comprises a cylindri cal body 17, a tube sheet 18 formed integral with 'one end of the body 13, and an end construction 19 closing the other end of the body. A partition 20 may be disposed within the header to eect a multiple pass dow of uid through the tubes, as

will presently appear.

The end of the body 17 is provided with an integral circular flange 21 which is slotted at diametrically-opposed points as indicated at 22 in Fig. 7 to permit the insertion of the end construction 19 in assembling. The end construction 19 is a one-piece member comprising a ring portion 23 having a ange 24 engaging the inner side of the flange 2l, the ring 23 and ange 2e being integrally joined to the body 17 by any suitable means, for example, Welding as indicated at 25.

The end construction 19 is provided with a plurality of sector-shaped openings 26 having major and minor axes as indicated at 27 and 28,

respectively (see Fig. t). As will be observed from an examination of Fig. 2, the openings are shown as being of the same size and are disposed etrically about the central axis of the body 17. The openings 26 are sealed by cover plates which are also sector-shaped as shown. The cover plates 30 also have major and minor axes 27a. and 28h, respectively, which are larger than the A,corresponding

axes

27 and 28 of their respective openings (see Fig. 5). The reason for this is to provide a sealing surface about the periphery of the cover plate 30 to effectively engage the inner surface of the end construction adjacent the openings and thereby eect a clo- 5; sure for each-opening. The minor axis 28a of prises radial portions 19a separating the openings 26. These radial portions increase in thickness from the periphery toward the center of the end construction and thereby provide an unusually strong truss structure for resisting internal pressures in the header 15.

The cover plates 30 are held in position with respect to their respective openings by means of a spider construction 31 comprising a central portion 32 having an opening 33 therethrough for receiving a. bolt 34 which extends into a screw-threaded opening 35 in the central portion of the end construction 19, and a plurality of ra dially-extending linger portions 36 having openings 37 therethrough for receiving bolts 38 which are secured Within screw-threaded openings 39 in the cover plates 30. A tightening of the bolts 38 clamps the covers against the end construction as `will be readily appreciated.

In order to more eectively` hold the covers in place, additional means in the form oi a clamping ring 40 may be provided. As can be seen from an examination of Figs. 1 and 2, the clamping ring 40 is provided with a plurality of openings 41 which receive bolts 112, the latter extend'- ing into screw-threaded openings i3 provided in the cover plates 30 and, when drawn tight, serve as additional means for clamping the plates to the end construction.

As will be observed from an examination of Figs. l to 7, inclusive, the cylindrical body i7, tube sheet 18, and circular ange 21 are formed as a one-piece forging. The end construction 19 is also formed as a one-piece forging and is placed in position `within the header 13 by turning edgelli) wise, as indicated in Fig. 7, and inserted through the slotted portions 22 o the iianges 21. After the end construction 19 is inserted slightly over halfway into the body 13, it may be turned transverse to the axis of the body and positioned against the inner surface oi the ange 2l. With the parts in this position, the end construction and body are integrally joined by welding, as before explained. Previous to the insertion of the end construction in the body, the partition plate 20 is placed in the body, and, after the end construction has been turned and welded in position, the partition 20 may be arranaged in its proper position and securely welded to the adjacent surfaces of the body, end construction, and tube sheet.

A header construction so fo is extremely strong and will resist effectively unusually high pressures of the duid therein. The engagement of the peripheral ilange 24 of the end construction 19 with the inner surface or the iiange portion 21 and the integrally joining of the body and end construction by welding, provides an unusu ally strong and rigid joint with no part of the weld under tension. The cover plates 30 having their peripheral surfaces engaging the inner surface of the end construction adjacent their respective openings, provide a self-sealing closure for the opening, that is to say, the high pressure of the iiuid inside the header construction only acts to more effectively seal the openings by forcing the cover plate against the end construction. Suitable gasket means a9 may be provided between the overlapping surfaces of the cover plate and end construction to edectively seal the openings 26.

The partition 20 divides the header 13 into two chambers -45 and 46. An t f- 47 is provided in the wall of the body 17 and communicates with the ober t5, and a second opening 48 is pro- Eff vided in the bodyl'land communicates with the chamber 46. The purpose of the openings 47 and 4B is to admit and discharge the fluid to be circulated through the tubes 16. l The header construction 15 is formed in identically the same manner as'the header construction .13, the only difference being that it is smaller in In operation, either the -iiuid tobe heated-cr to be cooled is admitted into the -chamber through the opening 47 and enters the ends of those tubes 16 communicating with this chamber and flows therethrough to the header 15 which defines a chamber 49 communicating with the ends of all of the tubes 16. The fluid is returned through-the remaining tubes to the chamber 46 in the header 13 and then conducted away from the apparatus through the opening 48. It is to be observed at this point that, while we have shown a two-pass construction, it will be readily understood that by the provision of additional partitions in the header 13 and header 15, any number of passes may be provided for the ow of 'j huid through the tubes.

The other uid is admitted to theshell through an opening 50 and is discharged from the shell through an opening 51. A removable longitudinal baille 52 provides for the flow of fluid from the opening 50 lengthwise of the shell above the baille, as viewed in Fig. 1, around the end of the baille and thence longitudinally of the shell beneath the baille and out the discharge opening 5l. If desired, additional longitudinal baiiies may be provided for causing the fluid to pass 1ongitudinally of the shell more times than just described, or transverse baiiles may be provided for effecti ing a more intimate engagement of the iiuid' passing through the shell over the tubes. The additional longitudinal and transverse-bellies are not shown, but these and their functions are both well known in the art and further disclosure is deemed unnecessary. f

' In Fig. 9, we have illustrated a modified form of header which comes within the scope of the present invention. The only difference between this header and the one previously described is that,

` instead of having a tube sheet formed as a single forging with the body of the header, it is formed as a separate piece and engages the inner surface of a flange 61 provided at the end of the header and is welded thereto. In Fig. 9, we have also indicated the manner of assembly of the end construction 63 and tube sheet 60 which is similar .'to that described in connection with the end construction of the previous modification. As will be observed from an examination of this view, they are both inserted through slotted openings 64 provided in a flange 65 in the end of the body jopposite the shell. After insertion, they are,

turned, the tube sheet being arranged -so that its outer periphery engages the surface of the flange 61v and is securely welded thereto. 'I'he end construction 63 is turned within the body and brought back against the inner surface of the flange 65 and is welded thereto in the same manner as in the previous modification.

It is to be observed that, vwhile we have shown the sector-shaped openings 26 as being of the ,same size, insofar as the broader aspects of our tioned about their respective openings.

in mind, it is to be understood that the inventionv sizes. -A construction'A may be designed wherein spect to theirrespe'ctive openings. ever, is only possible where Athe partitions provided in the header for'dening' separate cham-- bers do not interfere with the positioning of the.

cover plates. In'cases where only one partition is provided, as is shown in the preferred embodiment, the two openings at each side Aof the parti-- tion may be so arranged 'that the two cover plates can pass through one opening and then be 'posi- With thisl in its broader aspects should only be limited to invention are concerned, they may be of different a. construction Wherein'the axes of each cover'.

plate are' larger than the corresponding axes of their respective openings and one axis of each cover plate smaller than the major axis of one of the openings so that all the cover plates can at least be inserted through this one opening. It is preferred, however, that the cover plates be constructed in size and'in the manner shown in the drawings so that the greatest degree of access may be had to the ends of the-tubes.

It will be seen from the foregoingthat we havel placed'in the header previous to assembly and,`

after the end construction is in position, integrally joined to the body by'welding.

lWhile we have' shown our invention in two forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changesand modications without departing from the spirit thereof, and we 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 we claim is:

1. In heat exchange apparatus, al header construction comprising a tubular body; a tube sheet Irigidly ilxed to one end .of the body and having a plurality of holes therethrough for receiving tube ends; anend construction rigidly fixed to the other endjof the body and having a plurality of sector-shaped openings therethrough distributed symmetrically about the central axis of the body; at least one of the openings having major and minor axes; a plurality of cover plates disposed within the body, there being one plate for each opening in Athe end construction and each cover plate being of such dimensions and so arranged with respect to its respective opening that the surface of one side thereof adjacent its periphery engages thef inner surface .of the end construction adjacent the opening so as to eifect a complete closure for the opening, the cover plate corresponding to at least said one opening having major and minor axes with its minor axis larger than the minor axis of said one opening, but smaller than the major axis of such opening, each of the remaining cover platea having axes larger than the corresponding axes of their respective openings and at least one axis of each plate being smaller than the major axis-of said one opening whereby all of the cover plates can the other end of the body and having a plurality of openings therethrough, each of which has major and minor axes; a plurality of cover plates disposed within the body, there being one plate for each opening in the end construction and each cover plate being of such dimensions and so arranged with respect to its respective opening that the surface of one side thereof adjacent its periphery engages,the inner surface of the end construction adjacent its respective opening so as to eilect a complete closure for such opening; each cover plate having major and minor axes and the minor axis of at least one of the lcovers being larger than the minor axis of its respective opening, but smaller than the major axis of such opening, and the minor axis of `each of the remaining cover plates being larger than the minor axis of its respective opening and smaller than the major axis of the opening for said one cover whereby all of the cover plates can be inserted through the opening for at least `said one cover plate and at the same time the cover plates being of sufficient size to eiect a closure for their respective openings; and a common means for holding all of the cover plates in position about their respective openings.

3. Apparatus according to cLaim 1 vwherein the tube plate and body are a single forging.

4. Apparatus according to claim 1 wherein the tube plate, body and end construction are inte- "grally joined.

5. Apparatus according to claim 1 wherein the tube plate and body are a single forging, and the end construction is of forged metal welded at its periphery to the end of the body.

6. Apparatus according to claim 1 wherein a common means is provided for securing all of the cover plates in position about their respective openings.

7. Apparatus according to claim 1 wherein a common means is provided for securing all of the cover plates in position about their respective openings, and said means comprises a spider construction including a center member secured to the center of the end construction at the outside thereof and arms radiating from the center member, there being an arm for each cover plate and each cover plate being held against the end construction by a bolt connecting such plate with its respective arm.

8. Apparatus according to claim 1 wherein the body and tube sheet are a single forging and an inwardly extending flange is formed integral with the body at the end opposite the cam, and the end construction engages the inner surface of the flange and is welded thereto.

9. In heat exchange apparatus, a header construction embodying a tubular body, a tube plate rigidly iixed to one end of the body, an end construction ixed to the other end of the body and provided with a circular series of openings affording access to the interior of the body and to the tubes, cover plates for the openings having boundary seating portions arranged to t 'boundary seating portions formed at the inner side of the cover portion, said openings and cover plates being formed with major and minor axes with the minor axes of the cover plates less than the major axis of at least one of the openings, said openings being separated by radial portions of the end construction which increase in thickness inwardly and radially to provide a relatively stii cover, and means for holding the cover plates in place with said seating portions engaged.

JOHN A. POTTER. JOHN P. RATHBUN.