US1803035A - Heat exchanger - Google Patents

Description

April 28, 1931. J. A. POTTER 1,803,035

HEAT EXCHANGER Filed June 30, 1930 VIH- Il |l l n! pv' peoooQoQooo/ 32\Qoooooooooo/35 INVENTOR John H. Potter* BY @15M ATTORNEY baille between. the tubes Patented Apr. 28, 1931 UNITED STATES PATENT OFFICE JOHN A. POTTER, 0F MOORES,

TRIC & MANUFACTURING HEAT EXCHANGER Application led .Tune 30, 1930. Serial No. 464,922.

My invention relates to tubular heat exchangers of the multi-pass type having a of the passes and it has for an object to provide apparatus of '.ihis character having a removable tube bundle and a removable baflle with improved sealing means for the baffle;

My invention has for a further objectto provide sealing means for the baille which .vill effect a fluid-tight joint between the baille and the shell of the heat exchanger but which, at the same time, will not interfere with the freedom of removal of the baille and the tube bundle from the shell.

In my copending application, Serial No. 463,123, entitled Heat exchanger, and assigned to the Vestinghouse Electric & Manufacturing Company, I disclose and claim a form of heat exchanger having a shell with .L tube bundle and a baffle disposed interiorly of the shell and arranged to be readily removable therefrom. In the embodiment, there disclosed, I effect a substantially fluid- .tight joint between the baille and the shell with an improved form of sealing structure which does not interfere with the freedom of removal of the tube bundle and the baille from the shell. j

In thepresent application, I show a struc- ',ure for effecting a seal between the baille and the shell, which structure is arranged in accordance with the principles set forth in the aforesaid application, but which is of a more simplified form and less expensive to construct. As shown in the present application, the sealing structure embodies, in its preferred forni, a strip at the lateral edges of the baille and arranged to directly engage the interior surface of the shell. In another form, the strip may be secured to the interior of the shell so as to directly engage 011e side of the lateral marginal portions of the baille. While the strip employed in this embodiment may be of one layer, or in other words a single element, I prefer to utilize a laminated strip composed of a plurality of relatively thin elements which are arranged to form a seal in the nature of a labyrinth. The element or elements are sufficiently flexble to permit them to be held in sealing engagement in response to fluid pressure. In addition, in the present embodiment, I disclose an improved form of interior baille structure for compelling the fluid to more I A further object of my invention is to.

form these strips with sulicient flexibility to permit the differential pressure existing on opposite sides of the baffle to press the free edges of the strips into continuous and substantially fluid-tight engagement4 with the f shell or the baille.

A still further object of my invention is to provide a. substantially fluid-tight joint, in apparatus of the type designated, which includes adjacent substantially co-extensive abutment surfaces and a plurality of strips fixed along one of the abutment surfaces and responsive to iuid pressure toengage the adjacent abutment surface.

A still further object of my invention is to provide, in the type of joint designated, a flexible sealing strip secured along one of the abutment surfaces, presenting a plurality of narrow lines of contact with the adjacent abutment surface.

Still another object of my invention is to provide improved baffle means for causing the fluid to more completely traverse the full length of the shell.

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 drawing forming a partof this application, in which:

Fig. 1 is a view, in sectional elevation, of one form of heat exchanger arranged 1n accordance with my invention;

Fig. 2 is a horizontal plan view taken of the arrangement shown in Figs. l1 to 4,

vshowing the sealing strip fixed to the shell instead of the baffle; and, y

Fig. 'G is a detail view of another modification of the. arrangement,shown in Figs. l

to 4, showing the sealing strip supported :at its center and free at both edges.

Referring now to the drawing, I show, in Fig. 1, a heat exchanger embodying a shell 11 having-.secured thereto flanges 12 and 13 and having located, near one end lthereof, an in let connection 14 and an 0ppositely-disposed outlet yconnection l5 for circulating a fluid medium through the shell. A tube bundle 16 is longitudinally disposed within the shell and is supported, at one .if its ends, in a ystationary tube plate 17 secured to the flangeV 12, and is supported at the other. of its ends in a floating tube `plate 18. A cover member 19, having an inlet connection 20, an oppositely-disposed l outlet connection 21 and a partition 22, cooperates with the tube plate 17 to. provide an upper inlet box or chamber 23 for directing a fluid into Ythe upper portion of the tube bundle and a lower box or chamber 4 for receiving the fluid from the'lower portion of the tube bundle. The cover 19 is removably secured to the tube plate 17 to provide access to the tubes.

A bonnet member 25 cooperates with the floating tube plate 18-to direct the fluid.

from the upper portion of the tube bundle back through the lower portion. The bonnet member 25 is securedv at its periphery with a fluid-tight jointv to `.tube plate 18.

A removable hood member 26 is secured tothe flange 13 and encloses the bonnet member 25 and the floating tube plate 18.

The tube plate 18 and the bonnet member 25 are so arranged that they fit loosely at iheir' peripheral portions in the interiorof the shell and hood member., which permits them to float back and forth to allow for relative expansion and contraction of the tube bundle with respect to the shell.

. A longitudinal baille plate 27, is disposed .l interiorly `of'th'e tube bundle 16 between the inletV ltand the outlet 15 and arranged to 'extend longitudinallyl of the shell for dividing the interior thereof into two passes or compartments, an upper pass 28 and a cent transverse lower pass 29. The longitudinal baflle 27 is secured at one end to the tube late 17 by any suitable means, such as wel ing, and is baille 27 in pairs in diametrically-opposed position. They are secured at their inner edges to the longitudinal baille 27 by any suitable means, such as welding. At their outer edges they are held in the desired position by longitudinal stay-bolts 34 and spacers-35. The stay-bolts are secured in the tube plate 17 and extend longitudinally through the transverse baffles. The spacers 35 surround the. stay-bolts with their ends in engagement with the sides of the adjabaflles. The transverse baffles are provided with openings 33, the openings in alternate `baffles being staggered with respect 4to the openings in the remaining baflles so as to produce a zig-zag flow of the fluid' as shown by the arrows. The tubes of the tube bundle 16, which are shown in broken outline in Fig. 1, pass through holes provided therefor in the transverse baflles and may be grouped somewhat as shown in Fig. 3.

` Supplementary longitudinal baffles 36 are provided in each of the passes, in the first pass 28 facing the inlet 14 and in the second pass 29 facing the outlet 15.' Each of these 'extend between the tube plate 17 -and the first transverse baille 32. However, openings 37 are provided in the ends of the supplementary baflles which abutl against the .tube plate 17 whereby the fluid is compelled to traverse the ,full length of the tube bundle in each of the asses.

The path o -flow of one fluid through vthe tubes of the tube bundle and the path of flow of another fluid through the interior of the shell will now be apparent from the foregomgdescription. In addition, it

will be observed that the tubebundle and the entire baille structure are tied together as a single assembly and are removably se- .cured as a unit in the shell by means of the 'tube plate 17.I The tube plate 18, the bonnet slrip 41 and a retaining strip 42 both secured, preferably, on the side of' the baffle subjected to higher fluid pressure, that is, the inlet side of the baille. rl`he sealing strip ll and the retaining strip 42 may be secured at their ends to the baffle by means of rivets 43. Intermediate of their ends, they are held in position on the margin of the baffle by the'edges of suitable slots or recesses 44 provided at the junction of the periphery of the transverse baffles 32 and the Alongitudinal baffle 27. By retaining the strips in position upon the baffle in this manner, they may be readily removed therefrom merely by cutting the rivets 43 holding them at each end. The retaining strip 42 besides holding the fixed edge of the sealing strips firmly against the baffle provides, also, a protecting guard over the laminations of the sealing trip so asto minimize the damage in handling.

rlhe laminations of the sealing strips 41 are made of yieldable or flexible material which is of such relatively small thickness hat, when in position to contact with the interior of the shell structure at a suitable angle, any very small pressure difference existing between the fluid flowing in the first and secondpasses of the shell, as caused 'iy the resistance of the tube bundle and baffle elements, compels the free edges of the sealing strips 41 to be pressed into engagement with the adjacent portions of ,the shell. One of the outstanding advantages of such .n arrangement, resides in the factthat the laminations may have such flexibility that they readily conform with any surface irregularities obtaining in the engaged surface of the shell resulting from commercial manu- "acture I prefer to make the sealing strip 4l of a. plurality of laminations so that the edges of "the individual lamina-tions form a plurality of lines contacts with the interior sur- .'ace of lthe shell. Each lamination is so `arranged that it is free to assume its own sealing position without interference 'from theother laminations. In thismanner, somewhat of the labyrinth type of seal is formed, that is, a plurality of lines of sealing engagement arranged in series. It is to be understood that, while I use a strip of a plurality of laminations, or, in other words, a plurality of thin strips arranged in sealing ent gagement, I l"may use a sealing strip comprising only one lamination. y I may also use a sealing strip having the fixed edge-thereof formed as a solid strip while the free edge r the edge in contact with the interior of the shell is yformed of a plurality of relatively thin webportions such as would be obtained Aby cutting longitudinal recesses in the free edge ofethe strip, thus having essen- .ially a plurality of single strips forming a plurality of lines of sealing engagement with the interior of the shell.

The sealing strip 41 may be biased toward a horizontal position so that, when raised to an inclined position at the timey of insertion of the baffle 27 into the shell 11, the laminations engage the shell with a spring tension. However, the pressure exerted upon the laminations by the higher fluid pressure existing on that side of the baffle is mainly relied upon for pressing the free edges of the laminations into continuous engagement with the adjacent portion of the interioi surface ofthe shell.

In Fig. 5, I show 'another form of seal embodying my invention in which the laminated sealing strips 4l, instead of being attached ,to the removable baille 27, are attached to the interior of the shell. The sealing strips are secured to the shell in a position above the longitudinal baffle 27, or on the side thereof exposed to the higher pressure.. The upper edge of the sealing strips are made fast to the shell while the lower edge is free to be flexed or pressed into engagement with the longitudinal bafile 27 in. response to the higher fluid pressure existing above the baille. The strip 42 is secured over the sealing strips 41 to retain the fixed edge in position and to provide a protecting guard over portions of the sealing strlps.

' Referring now to Fig. 6, I show a detail view of still another form of seal embodying my invention in which the laminated sealing strip 4l is secured substantially midway between its edges to the transverse baffles 32, and is free at both of its edges to engage, at one edge, the interior surface of the shell 1l and, at the other edge, the upper side of the baffle 27 in response to the fluid pressure difference on opposite sides of the baffle. In this embodiment the sealing strip 41, the retaining strips 40 and 42 are secured to a bracket 45 by means of rivets 43. The retaining strips 40 and 42 are placed on opposite sides of the sealing strip 41 and are spaced away from the edge thereof sufficiently to allow the latter to maintain the desired flexibility. The bracket 45 which is above the sealing strip is in turn secured to the transverse baille 32 by means of a. rivet 46. I may place the bracket 45below the sealing strip and secure it to the shell 1l or modify it in any other suitable manner that Will permit it to be secured to the shell 11 instead of the transverse baffle 321 The bracket 45 may be fitted-loosely about the rivet 46 for allowing the sealing strip to have a limited transverse and side-to-side movement for the purpose of permitting the flexible edges thereof to find their engaging position freely in response to fluid pressure.

In all embodiments, I\prefer`, according to my invention, to make the relatively -thin llll ` inlet and outlet the spirit thereof,

forming the plurality of lines'of seal, of the i Arequired strength and of sufficient flexibilityr to permit' it to `bend under fiuid pressure.

While in the embodiments of my invention illustrated and described,'I have' used sealingstrips on the side of the bafiie exposed to the higher pressure, it is to be understood that my invention is not confined' to using the sealing strips on this side only. y

Also, While I have shown 'my invention in three 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 and I desire, therefore, that only such limitations shall be placed thereupon as arevimposed by the prior art or as are'specifically set forth in the appended claims.

What I claim is:

1. In heat exchange apparatus, the combination of a shell, a removable tube bundle disposed in the shell, a removable baffle disposed in the shell and dividing the latter into first and second compartments, fluid means provided in the shell and arranged to circulate the iuid through the compartments in series, and a flexible strip fitted directly'between the inner wall of the shell and the baffle and responsive to fluid pressure for effecting a substantially flllllild-tight joint between the bafiie 'and the s e Y 2. -In heat exchange apparatus, the ,combination of a shell, a removable tube bundle y disposed in the shell, a removable baflie disposed in the shell and dividing the latter ind arranged to circulate the fluid throufrh the compartments in series, and a strip formed on a marginal portion of the baffle and having a flexible edge portion directly `engaging. the interior'surface of the shell, said fiexible edge portion being retained in fiuid-ti ht engagement with:

- the shell by the fluid substantially the interior surface o pressure difference vexisting on opposite sides of the vbaliie.

.ter into first and second compartments, fiuid.

inlet and outlet means provided in the. shell rated in the tube bundle structure into first and second compartments, fiuid -inlet and outlet means provided in the shell the shell and having a flexible edge portion engaging the baffle, said flexibleedge portion being retained in substantially fiuidtight engagement with'the baffle bythe fluid pressure difference existing'on opposite sides of the baffle.

4. In heat exchange apparatus, the vcombination of a shell structure, a removable tube bundle structure disposed within the shell structure, a removablebafile incorpoviding the interior ofthe shell structure into first and second compartments, fluid inlet and `outlet means provided in the shell structure and arranged to circulate fiuid through the compartments in series, a strip having oppositely-disposed fiexible marginal portions, one of the marginal portions e119'.

gaging the baflie and the other of the marginal portionsengaging the vinterior surface of the shell, and means to secure the strip intermediate the marginal portions thereof to the tube bundle structure, said flexible marginal ortions being retained in substantially fiui -tight engagement with both the baiiie and the interior surfacev of the shell by the fluidpressure difference existing on opposite sides of the bafile... c a heat exchanger l5. The combination with including a shell element .and 4a bale element dividing the interior space of the shell element `into first and second passes, of laminated. flexible elements responsive to the pressure difference existing betweenthe first and second passes' for'forming a plurality of lines of seal between the lateral l marginal portions of the' baffle element and the shell element.

6. A heat exchange apparatus as' claimed in claim 5in which the laminated fiexible elements are composed of a corrosive-resistant material. A

7. The combination with a heat exchanger including a-shell velement4 and a removable baffle element dividin the interior space of the shell element into rst and second passes, of flexible metallic strip means carrled by one of said elements and cooperating with. l

the othelgelement to effect a plurality of narrow-lines of'seal in response to pressure .,difference existing between the `iirst and 'second passes.

8.A heat exchange apparatus as claimed in claim 7 in which the laminated exible strip is composed of a corrosive-resistant metal.

9. In a heat exchanger, in combination, a`- shell, a tube `bundle and baille removably supported in the shell, the inner. wall surface of the shell and the lateral marginal ortions of the bafile providing co-extending abutment surfaces,I and sealing means coopros ' into erating with the abutment surfaces for forming a substantially fluid-tight joint between the baille and the shell, said sealing means .including a flexed strip secured along one of said abutment surfaces kand retained in en'- gagement 4with the other of said abutment surfaces partly in response to spring tenslon existing in the stri and partly in response to the differential uid pressure existing on opposite sides of the baille.

10. In a heat exchanger, in combination, a shell, a tube bundle and baflle removably supported in the shell, the inner wall surface of the shell and the lateral marginal portions of the baffle providin co-extending abutment surfaces, and sea ing means cooperating with the abutment surfaces to form a substantially fluid-tight joint between`the baffle and the shell, said sealing means including flexible laminated strips secured along one of said abutment surfaces and retained in substantially fluid-tight engagement with the other of said` abutment surfaces in response to the differential fluid pressure exhausting on opposite sides of the baille.

11. In heat exchange apparatus, the combination of a shell, a removable tube bundle disposed within the shell, and embodyin a removable baffle member, said baffle mem er having a ortion thereof arranged' to form a joint wit a portion of the interior surface of the shell, said joint including a plurality of strips of flexible sheet material each secured to one of the portions and each responsive to fluid pressure in one direction for engaging the other portion, and said joint also including a stri of relatively rigid sheet material secure to one of the portions in a position to embrace the fiexible strips.

12. In heat exchange apparatus, the combination of a shell, a tube bundle, means for supportin the tube bundle within the shell and provi ing for removal thereof fromthe shell, longitudinally-extending. and transversely-extending baffles incorporated in the tube'bundle and removable therewith from the shell, a plurality of flexible strips secured to the lateral edges of one side of the longitudinal baffle, means responsive to fluid ressure in the shell for retamin the flexile strips in engagement with t e interior surface of the shell to effect a substantially fluid-tight joint between the longitudinal baffle and the shell, and means including slots formed in the transverse baffles for securing the flexible strips in position on the longitudinal baille. l

-13. In heat exchange apparatus, the combination of a shell, a removable tube bundle disposed within the shell and embod a removable baille member, said baffle mem r arr d to divide the interior of the shell andsecondpasses, fluid inlet and outlet means provided in the shell and arranged for circulating a fiuid through the passes in series, whereby the average fluid pressure obtaining inthe first pass is relatively higher than the average fluid pressure obtaining in the second pass, and means for effecting a substantially fluid-tight joint between the marginal portions of the baffle and the adjacent portion of the interior surface of the shell, said joint including a plurality of flexible members secured at one of their edges along the marginal portions of the side of the baiile exposed to the higher fluid pressure and having their other Vedges held in sealing engagement with the interior surface of the shell by the fluid pressuie difference obtaining between the passes.

14. In heat exchange apparatus, the combination of a shell, a tube bundle structure, means for supporting the tube bundle Structure within the shell and providing for removal thereof from the shell, a longitudinally-extending baffle and a plurality of transversely-extending bafiles incorporated in the tube bundle structure, and a flexible strip for effecting a substantially fluid-tight joint between the longitudinal baffle and the shell, said transverse baffles cooperating with the longitudinal baflle to retain an edge of the flexible strip in Vfixed position upon the latter.

15. In heat exchange apparatus, the combination of a shell, a tube bundle, means for supporting the tube bundle in the shell and providing for removal thereof from the shell, a baffle extending longitudinally within the shell and removable therefrom with the tube bundle, said baille being arranged to divide, the shell into first and second passes, means for effecting alsubstantially Huid-tight seal between the baffle and the interior of the shell, said joint including a plurality of flexible strips extending longitudinally of' the shell in the first pass, and means for securing said strips at one of their edges to the interior surface of the shell and providing for engagement of the other edges of the strips with the baffle in response to the fluid pressure difference existing between the asses.

In testimony whereof, I have ereunto `subscribed my name this 26th day of June,

JOHN A.. POTTER.

Images