US1822698A

US1822698A - Baffle packing for heat exchangers

Info

Publication number: US1822698A
Application number: US479659A
Authority: US
Inventors: Harlan W How
Original assignee: STRUTHERS WELLS TITUSVILLE COR
Current assignee: STRUTHERS WELLS TITUSVILLE COR; STRUTHERS-WELLS TITUSVILLE Corp
Priority date: 1930-09-04
Filing date: 1930-09-04
Publication date: 1931-09-08
Anticipated expiration: 1948-09-08

Description

H. W. HOW

BAFFLE PACKING FOR HEAT EXCHANGERS Filed Sept. 4, 1930 Sept. 8, 1931.

HABLAN W. HOW, OF WARREN,

Patented Sept. 8, 1931 UNITED STATES PATENT OFFICE PENNSYLVANIA, ASSIGNOR T0 STRUTHERS-WELLS TITUSVILLE CORPORATION, OF WARREN, PENNSYLVANIA, A CORPORATION OF MARYLAND BAFFLE PACKING FOR HEAT EXCHANGEBS Application led September 4, 1930. Serial No. 479,659.

This invention relates to a packing for the baffles of heat exchangers. In heat exchangers the bafiies which divert the Huid in circulation so that it will pursue a longer course should fit` closely to the wall of the enclosing shell in order to avoid leaks which permit a short-cut in the movement of the fluid and reduce the efficiency of the exchanger.

It is therefore the objectof this invention to provide a packing between the baffle and the wall of the shell which permits the baffle and the tubes associated therewith to be readily and conveniently introduced into the shell and removed therefrom and still insure a tight joint between the baffle and the shell when the apparatus is in use so as to obtain the maximum efficiency.

In the accompanying drawings:

Figure 1 is a vertical longitudinal section of a heat exchanger equipped with this invention.

Figure 2 is a horizontal section of the same taken on line 22 Fig. 3.

Figure 3 is a cross section taken on line 3 3 Fig. 1.

Figure 4 is a fragmenetary cross section, on an enlarged scale, taken on line 4-4 Fig. 5, and showing the packing between a longitudinal edge of the baffle and the adjacent part of the shell.

Figure 5 is a horizontal section taken on line 5'-5 Fig. 4.

Figures 6 and 7 are fragmentary longitudinal sections of the baffle and the packing strip thereon showing different ways of arranging the opposing ends of adjacent sections of the packing strip.

In the following description similar characters of reference indicate like parts in the several figures of the drawings.

The numeral 10 represents the shell, casing or housing of the heat exchanger which is preferably made of sheet metal and arranged horizontally and provided with an inlet 1l for one of the fluids to be circulated and an outlet 12 whereby this fluid may discharge from the shell, said inlet and outlet being preferably constructed in the form of tubular necks which are arranged diamctrically opposite each other on the upper and lower sides of to the front end thereof.

At its front end the shell is provided with an annular attaching ring or collar 13 the face of which is provided with an annular recess or rabbet 14 which contains a gasket or packing 15. At the rear end of the shell the same is provided with an annular attaching ring or collar 16 which forms part of a stuffing box as will be hereinafter described and which containsan internal annular rabbet or enlarged bore 17.

Within the shell a plurality of sets of heat exchanger tubes is arranged lengthwise, two

sets

18 and 19 being shown in the present instance, the upper set 18 being arranged above the center of the shell and the lower set 19 below this center.

The front ends of these tubes are secured to a front tube sheet 20 which bears with the rear side of its marginal part against the gasket 15. Arranged in front of the shell and the front tube sheet is a hollow manifold body 21 which is provided at its rear end with an annular rabbet or recess 22 containing a gasket or packing 23 bearing against the front side of the marginal part of the front tube sheet 20, the latter being clamped between the front attaching ring 13 and the rear end of the manifold body 21 by means of fastening bolts 24 connecting the adjacent parts of the attaching collar 13 and this manifold body, as shown in Figs. 1 and 2.

On its upper side the manifold body is provided with an inlet 25 for another of the fiuids to be circulated and on its lower side with an outlet 26 for this fluid, said inlet and outlet preferably having the form of tubular necks. Extending horizontally across the central part of the front manifold body is a partition 27 which divides the interior of the front manifold body into an upper connecting chamber 28 which communicates with the front ends of the up sets of tubes 18, and a lower connectln chamber 29 which communicates with the front ends of the lower set of tubes 19, said partition 27 having its rear edge fitted against the adjacent central -par't of the the shell adjacent front tube sheet 2O through the medium of a packing or gasket 39 so as to form a leaktight joint therebetween.

Arranged in front of the front manifold body is a cover 31 which is provided with a central horizontal rib 32 engaging with the front edge of the partition 27 through the medium of a gasket or packing 33 and having its marginal part connected with the rear end of the manifold body by means of bolts 34 and also bearing against a gasket or packing 35 which is seated in an annular recess or rabbet 36 on the front end of the manifold body, as best shown in Fig. 1.

The rear ends of the several heat exchanging tubes are secured to the rear tube sheet 37 which latter is provided at its edge with a forwardly projecting joint sleeve 38 which extends forwardly into the interior of the shell 10. Arranged in rear of the rear tube sheet is a manifold cover 39 forming a connecting chamber 40 which places the rear ends of the upper and lower sets of heat exchange tubesin communication with each other. Adjacent to its margin this rear cover is provided with a forwardly projecting annular flange 41 which projects into the rabbet or recess 17 of the rear attaching collar and bears against a packing 42 therein. The marginal parts of the rear cover 89 and the rear attaching ring 16 are connected with each other bv means of bolts 43 so that upon tightening these bolts the packing 42 will be compressed and held tightly around the sleeve 38 so as to prevent leakage from the space within the shell to the rear ends of the heat exchange tubes while at the same time permitting the rear tube sheet 37 to move lengthwise of the shell in response to expansion and contraction of the heal exchange tubes resulting from changes in temperature of the fluids which are circulated through the shell and the heating tubes.

Arranged lengthwise between the upper and lower sets of the heat tubes 1S, 19 is a baille 44 which preferably has the form of a flat plate made of metal and extending in a horizontal plane. This baffle is connected at its front end with the rear side of the front tube sheet 20 by means of a welded joint 48 or other suitable means while the rear end of this baille terminates short of the rear tube sheet 39 so as to form a transfer gap or passage 49 therebetween. The longitudinal edges of close to the inner longitudinal side of the wall of the shell so that the circulating fluid entering, say through the inlet 11, will be compelled to be passed-horizontally rearward through the upper passage 50 formed between the baflle 44 and the upper part of the shelll` thence downwardly through the` passage 49, thence horizontalh7 forward through the lower passage 51 formed bethis baille are arranged' 'U-shape form in tween the baffle 44 and the lower part of the shell and thence out through the lower outlet 12. The other fluid which is to be circulated may enter, for example, through the inlet 25, thence through the upper connecting chamber 28, thence rearwardly through the upper set of tubes 18, thence downwardly through the rear connecting chamber 40, thence forwardly through the lower set of tubes 19, thence downwardly through the lower connecting chamber 29 and out through the outlet 26.

In the use of this apparatus the relatively hot and cold liquids to be circulated may be passed respectively either through the interior of the tubes or through the shell along the exterior of the tubes and these fluids may either move through their respective passages in parallelism or the same may move in opposite directions through their respective passages, the particular manner o handling these fluids being governed by conditions where the apparatus is installed, also the character of the fluids between which the heat is to be interchanged. In all cases however, the temperature of the fluid on the exterior of the tubes and the temperature of the fluids on the interior of these tubes influence one another by an exchange of the heat, tending to raise the temperature of the cooler liquid and lowering the k,temperature of the hot liquid.

In order to obtain the maximum heat eX- changing efliciency of this apparatus it is necessary to maintain a leaktight joint between the longitudinal edges of the baille 44 and the wall 10 of the shell so as to prevent the fluid entering the shell from passing through the joints between the longitudinal edges of the baffle 44 and the wall 10 and make a short-cut from the inlet to the outlet end of the shell instead of being compelled to travel to and fro through out the length of the shell and around the rear edge of the baille which constitutes a very much longer course for the fluid and insures a greater transmission of the heat from one of the streams of fluid to the other.

To insure a practically tight joint between the longitudinal edges of the baflle and the wall of the shell for this purpose, packing means are provided which are preferably constructed as follows:

Between each longitudinal edge of the baffle and the adjacent part of the shell is arranged a packing strip which in its preferred form is made up of a plurality of longitudinal sections which have their opposing ends arranged adjacent to each other' so that in effect they produce one continuous strip. Each of these sections is preferably constructed of sheet metal which is of cross section and provides a transverse bearing web 52 which engages with its outer side against the inner side o the .adjacent pa't of the shell wall 10, as

best shown in Figs. 4and 5,and two longitudin al' legs vo rillan'ges 53 proj ecting' inward'- ly,i'1 'om1the'opposite longitudinal edges of the web and .engaging with opposite ilat sides of the adjacent longitudinal edge portion of the -baille 44, as. shown in the same figures.l

The several sections of cach packingstrip areyieldingly heldin'engagelnent with the Shell wall by spring means which in its pre,- ferred construction consists of an undulatcd orA serpentine shaped strip of spring meLal 54 vwhich `is arrangedlbetween the inner side of vthe` packing strip webs 52 and the adjacent longitudinal edge of the baille 44, and bears with its alternating crests against the adjacent web of the'paking strip and the. longitudinal edge of the baille, as best show-n in Fig. 5. By this means the stripfo spring metal 54 tends to constantly press thepacking strip away from' the baille -and into en-l gagement with the shell wall and hereby maintain a ipractically tight joint between the opposing longitudinal surfaces of the same through which the respective circulating fluid cannot pass-and take a `short-cut in its flow, but instead is compelled to take a longer course as above described and @thereby insure thel maximum heat exchangingeilect-,of the apparatus.

fIIi order to prevent-'the packing ystrips from Abecoming detached from theA baille when the latter is withdrawn'pfrom 'thel shell together with th'e' cluster 6r bundle'of .

tubes

18 and 19, limiting mea-ns are provided which in their preferred form consist of stop pins or screws 55 which are securedtothe baille 44 and extend through transverse slots 56 in the flanges of the respective packing'st rip,'the pinsI which pass through the opposite flanges `orlegs -of the sameA strip beinglpreferably staggered relatively to each other so. that the pins or screws can be inserted in the baille from opposite sides of the'A .Same without`-interference with each other.

The ppposing ends of adjacent sections of the packing strip may either, abut Aagainst Ieach other as shown at 57l in Fig. 6 or they same may extend one o .ver the other in the form of an overlapping or' telescopic joint.'

as shown at 58 in Fig. 7, but in either case the opposing ends of adjacent packing strip sections are arranged in `close .engagement so asjto form a practicallyjfluid-tight joint between the same'. l' ,Bymaking the'packing strips in sections `the same can'- be applied tQ-the baille more readily and the same are also more ilexible inasmuch as the several'sections of each strip'` are free to adapt themselves'individually -to the contour of the adjacent part of'tlle shell wall in-case any inaccuracies or irregularities Ioccur in the same, and thereby provide a leaktight joint between the baille and the cylinder wall throughout the length of the opposing surfaces of these members.

When the cluster of tubes is removed from the shell together with the baille tube sheets and packing strips, the lateral movement of the packing strips relative to the baille is limited by the stopping effect of the stop pins 55 engaging with the inner ends of the slots `56 in the flanges of the packing strips. Preparatory to introducing the tubes, sheets, baille and packing s'a-ips into the shell the packing strips are pressed inwardly toward the longitudinal edges of the baille a Sullicient extent to permit the packing strips topass into the shell, and after these stripsI have been introduced into the shell the same 'are released so as to permit the springs 54 to press the packing strips outwardly into engagement with the shell wall and form a' tight joint therewith.

This means for packing the joint between thev baille and the 'shell Wall avoids the necessity of any accurate. or expensive fitting of the baille relative to the wall of the shell vand instead permits of leaving a clearance space of varying width between the longitudinal edges of the baille and the shell wall Vwhich permits of the free introduction of the baille into the shell and the removal thereuse.

. v Moreover, thisy construction of packing device between the baille and shell 1s very simple and mexpensive 1n construction and not ,only capable of being easily applied to the baille but is also not liable to der. f

I claim as my invention: d 1; A heat exchanger comprising a shell having a fluid inlet and a fluid outlet, a

get out of or- -plurality of sets of tubes arranged in said shell, tube sheets mounted 'at opposite ends of said shell and connected with opposite ends of said tubes, a baille arranged between the sets of tubes and having longitudinal edges arranged adjacent to said shell, and packing means interposed between the longitudinal edges of said baille and said. shell and comprising a packing strip having a web engaging said shell and flanges on opposite longitudinal edges of said web whichengage opposite sides of the longitudinal-edge portion of said baille, and spring means for holding said packing strip yieldingly in engagement with said shell. 2. A heat exchanger comprising a shell having a fluid inlet anda `fluid outlet,j a plurality of .sets of tubes arranged in said shell, tube sheets mounted at opposite ends 'of said shell and Aconnected with opposite ends of said tubes, Va baille arranged between the sets oftubes and having longitudinal edges arranged adjacent to said shell, and

packing 'means interposed between the longitudinal edges of said baile and said shell and comprising a packing strip having a web engaging said shell and flanges on opposite longitudinal edges of said web which engage opposite sides of the longitudinal edge portion of said baille, and a serpentine spring interposed between the edge of said baffle and the inner side of said web and operating to hold the packing strip yieldingly in engagement with said shell.

3. A heat exchanger comprising a shell having a fluid inlet and a Huid outlet, a plurality of sets of tubes arrangedin said shell, tube sheets mounted at opposite ends of said shell and connected `with opposite ends of said tubes, a baille arranged between the sets of tubes and having longitudinal edges arranged adjacent to said shell, and packing means interposed between the longitudinal edges of said baille and said shell and comprising a packing `strip having a web engaging said shell and flanges on opposite longitudinal edges of said web which engage opposite sides of the longitudinal edge portion of said baille and are provided with transverse guide slots, retaining pins secured to said baille and passing through said slots, and spring means for holding said packing strip yieldingly in engagement with said shell.

4. heat exchange comprising a shell having a fluid inlet and a fluid outlet, a plurality of sets of tubes arranged in said shell, tube sheets mounted at opposite ends of said shell and connected with opposite ends of said tubes, a baille arranged between the sets of tubes and having longitudinal edges arranged adjacent. to said shell, and packing means interposed betweenthe longitudinal edges of said baille and said shell and comprising a packing strip having a web engaging said shell and flanges on opposite longitudinal edges of said web which engage opposite sides of the longitudinal edge portion, said strip being made in sections and the end of adjacent sections being close 'toathei l 5. A heat exchanger comprising a shell having a fluid inlet and a fluid outlet, a plurality of sets of tubes arranged in said shell, tube sheets mounted at opposite ends of said shell and connected with opposite ends of said tubes, a baflle arranged between the -sets of tubes and having longitudinal edges arranged adjacent to said shell, and packing means interposed between the longitudinal edges of said baie and said shell and comprising a packing strip having a web sections and the ends of adjacent sections abutting.

6. A heat exchanger comprising la shell having a fluid inlet and a iuid outlet, a plurality of sets of tubes arranged in said shell tube sheets mounted at opposite ends of said shell and connected with opposite ends of said tubes, a baille arranged between the sets of tubes and having longitudinal edges arranged adjacent to said shell, and packing means interposed between the longitudinal edges of said bale and said shell and comprising a packing strip having a web engaging said shell and flanges on opposite longitudinal edges of said web which engage opposite sides of the longitudinal edge portion of said baille, said strip being made in sections and the ends of adj acent sections overlapping one over the other.

In testimony whereof I hereby afiix my signature.

HABLAN W. HOW.

-lao