US2640686A - Heat exchange type of tank heater - Google Patents

Description

June 2, 1953 J. w. BROWN, JR 2,540,685

HEAT EXCHANGE TYPE OF TANK HEATER Filed Aug. 30, 1949 2 Sheets-Sheet 1 JNVEN TOR. Jay/v 14/ fimnw, J/e.

ATTORNEYS.

June 2, 1953 J. w. BROWN, JR 2,640,685

HEAT EXCHANGE TYPE OF TANK HEATER Filed Aug. 50, 1949 2 Sheets-Sheet 2 A 7' 7 ORA/E YJT Patented June 2, 1953 poration of flhio "Arn .iwt e Au ust 30, .49;;Seriak 111532 :Zfllaims. 1 :This invention relates -to heat exchangers-and @more particularly to heat exchangers adaptedto 5-.heat -l-iquids-w-ithin largetanks.

:In the storage of viscous liquids, =-it is #fre- :quently necessary to provide heating m-eans in.

the storage tanks toheat-the contents sothatthe wiscosity'of -the liquids will be reduced to apoint at which the liquids willfiow-readily and-at which "they :can :be' pumpedeasily. L-t has been -the-practice heretofore to install horizontally extending heat exchanger tubes near the bottom of -=the tanks'in order to accomplish-this purpose. -Such installations -.-are open to objection in several respects: the repair :and replacement-' of the tubes is difficult; "the eificiency of the heat exchangers is not initially high and "is further reduced :in service by the accumulation of sediment on the tubes and eachinstallation" has to be-individual- .designed and constructed for the particular job.

A general object of the present invention-is to provide heateexchangers--particularly adapted-E01 use in tanks inflwhich the above notedldifliculties -are .eliminated. :More specifically, itis an-ob- =ject of the invention to provide :tank heaters e enee hie 1 id l l 9 1111 1 1395 9 i-elm an e e e i -m ife 9 pi e -dis ens s ,side of the walls of the tank.

Further objects and .ad, antages of my invention will beoome apparent from the jollowingde- 'scription of a preferred form thereof, .reierence bei mad to the aee m any n raw ne in h ehi e i a el a p r l i e tie showing a t i a in tallati of ,my .ten ,'heaters in a large storage tank; Figure is ,a plan vi w o th nk sh n., su e.1 .with t e top r .eov r rem e ieu e i e r rt ea sectio a new on an nlare dieee l ating one o th heaters of Figure 1 with parts loroken away ,to

show the construction of" the preferred tankwall n ie 451 a lan ewe tt hea e shown inFig-ui'efi.

' typical1instal-lation of tank heatersembody- -ing th'e "present invention as applied to :a :large tank indicated in-general at Tisshowninfi'fi- Cl. iii-slim) e u-re l of 'th-e drawings. i his tankwwhioh may be of the type utilized -'-i or storage of #heavy lQ'ils ol -V iscous -chemicals,*has a; bottom =-!i3,a cylindrical side wall -'-|-I'-=and; domed top '12. Iii-order to heat the conten-ts of -'-the tank, a number of heaters embodying the present invention ---and indicated general --at ift are -disposed -Withil1 the -tank. shown Figure 2, *the *heaters --are positioned near {the tank'wall H -=and rare nniformly'spaeed apart around *the tank. l he heaters are connected 'to the--;steam-maniiol d it *through exterior-connectingpipes -l'-"l, wall io'i-nt -'--f1tt-ings +8 and interior conneetin-g -pipes -Ni. The bottoms of the heaters are connected tc a condensate -;rnanifold '28 through exterior oon- "neoting pipes f2 wall jointfittings 22 and in- -ter-ior connecting pipes 23. "Pedestals 2- 2 sl pport -the heatersabove the floor Hl-ofthe tank. In order to provide a :large --amount of heat gi "tra es-iergsuriace i-n a rel-atively -smalhspace, each heater, asshownpartieularly in Figures -3--and" i, is made up of two concentric rows of vertically extending externally tinned heat exchanger tubes. The tu-bes-i-n the outer row are-indicated by--reference '-chara-oter H256, and "the tr bes in -the {inner row by reference character l. 9AM of these tubes ;-preieraibly are provided with a plu -ral=ity of *longitudinally extending external "251 accordance with-the--teaohings of any prior Patents -Nos. 2361 l36 and %,2615137, "These mem-bers give -eaeh "tr be greatly --extend ed su-riace area in -contact with the commodity within the tank,--and because-o*f their yertical arrangemerit, they create upwardfiow of-the con'rmed- -it y along thelongitudinally extending fins, thus :e e ii g' 1e ieene ie r i e 'l tien e ffiui fi th mi re-W ia ee x the e e "Wei e "th tan "i the Leon .e t e hea r and down rd n t center of thetank. "The circulationso obtained greatl ,i ie iea the eme ne of hea transfer of the vertical tubes as com ared with horizontell dis o ed es and iurthe er the e i eaj -m iiee ra t ee ly elimina ede o tion .e eed men eni tube a d ins e mainte n .ei' "th e rig l .effi'e ene e th h a er it eu l eutf eee e d .oftim ei t su pl ea in m d m "llthe i i bee th ,t le e i an 'flare'ieen e te at t ei 34121 1??1 :te ibeade l} the h e ib i ee ne ted i tu to th e "unp1. p 3 .9- jThe connections between-the tubes 26 and "the headertl are-made-jby welding the ends cfthe tubes, which are not finned, "into apertures in h b t om e ih he ee ie wn f e he 1:455 tubes -21 are secured to horizontal apertures *in the header 31' by bending the unfinned end portions of the tubes as shown at 33 and weldin them within the horizontal apertures as shown at 34.

Similar connections are made at the bottom of the exchanger, the bottom header 36, which is connected to the interior condensate pipe 23, being welded to the extensions of the tubes 26 as indicated at 31 and to the curved extensions 38 of the tubes 21 as indicated at 39.

In order to support the heaters within the tank, a pedestal 24 is disposed beneath each heater. Each pedestal is made up of telescoping tubes 4| and 42 welded together as at 43 to provide a pedestal of the required height for the particular installation. The tube 4| rests on the bottom ID of the tank while the tube 42 engages a plate 44 which in turn supports the bottom header 36.

In order to connect the inner connecting pipes l9 and 23 with the outer connecting pipes I! and 2|, respectively, through the wall of the tank, fittings l8 and 22 are provided. These are preferably of identical construction, and hence only the fitting 18 will be described herein.

In order that the connections may be made exteriorly of the tank, I preferably employ tubular connections of the general type shown and claimed per se in my Patent No. 2,449,052, issued September 14, 1948. By means of this type of connection a heater is readily installed by inserting the heater through the manway into the tank and then passing the connecting pipes l9 and 23 outwardly through apertures in the tank wall to join the corresponding pipes.

To provide this connection, a flanged tank fitting 45 is welded to the tank wall H at the aperture 46 through which the pipe l9 extends. Pipe [9 is provided at its end with an enlarged flange portion 41 which passes through and extends exteriorly beyond the tank fitting 45. The pipe is secured to the fitting by means of a split locking ring 48 which is seated within a groove 53 in the flange portion 41 and which engages an outwardly facing shoulder 54 within the tank fitting 45. Inward movement of the pipe relative to the tank fitting is thus eflectively prevented. In order to provide a seal between the pipe 19 and the tank fitting 45 a sealing ring or gasket 49 is drawn into sealing engagement against conical sealing surfaces 55 and B, of the pipe flange portion 4'! and the tank fitting 45 respectively, by a compression ring 50. The ring is pulled tightly against the gasket 49 by securing screws or studs 5| which extend through the ring and which are threaded into the flange of the tank fitting 45. When the screws 51 are drawn tight the pipe [9 will be held securely against the tank fitting 45 and an effective seal will be provided by the gasket 49 so that the contents of the tank will not leak at this point.

The connection to the external connecting pipe I 1 is made by providing the external pipe or conduit I! with an enlarged end 58 having a shoulder 59 which is engaged by the collar 60. Screws or studs 6|, extending through openings in the collar 60 and in the ring 50 and threaded into the flanged tank fitting 45, urge the collar 80, and hence the enlarged end portion 58 of pipe [1, toward the tank and bring the end portion 58 into sealing engagement with the enlarged end 41 of pipe IS. A gasket 62 is disposed between the opposed surfaces of the parts 47 and 58 to efiect a seal between the pipes.

By this arrangement and the similar arrangement at the bottom of the heater, a simple leakproof joint can be made between the connecting pipes and tank wall. The pipes ll and 2| leading t the manifolds can be disconnected from the pipes 19 and 23 without disturbing the connections between the tank wall and the pipes I9 and 23. All connections can be made and broken from the exterior of the tank and can be readily inspected. Any leakage of the joints will be evident from the exterior of the tank. Thus, installation of the heaters and maintenance is facilitated because any individual heater can be disconnected from the manifold and readily removed from the tank for inspection or repair, independently of and without interfering with the installation and operation of the other heaters.

From the foregoing description of a preferred form of my invention it will be evident that I have provided a simple and highly efficient tank heater. Because my heaters are made in units, heaters of the same construction can be adapted t a wide variety of uses. A single heater may be employed in a small tank; larger tanks may require two or three heaters; and still larger tanks may require a greater number of heaters. However, all installations can be made in substantially the same manner and with parts of generally similar or standard construction, thus making for economy of construction and installation.

Because of the efliciency of the vertical installation and of the finned tube heat exchange elements, my heaters are very compact for their capacity. My standard heaters are made with an overall diameter such that they can be installed in and removed from a tank through a standard 20 inch manway. The comparatively small size of the units makes them easy to handle as compared to single large heater installations of the prior art. The efiiciency of the heaters is such that they displace a small volume of fluid within the tank and hence do not greatly reduce the storage capacity of the tanks within which they are installed. Because the heaters are made in units, they can be installed easily in new or existing tanks, and units can be added or removed in accordance with the changing requirements of service.

Those skilled in the art will appreciate that various changes and modifications can be made in my invention without departing from the spirit and scope thereof. For example, instead of the two concentric rows of finned tubes shown in the drawings, three rows or only one row may be employed, and a different type of tank wall fitting such as that shown in my Patent No. 2,424,221 may be utilized if desired. Therefore, it is to be understood that my invention is not limited to the preferred form disclosed herein and that the scope of the invention is defined by the appended claims.

I claim:

I. In combination with a tank, a heater disposed within the tank and spaced from the side wall and bottom thereof, said heater being small as compared with the tank and comprising an annular upper header, an annular lower header, a plurality of heat exchange tubes having longitudinal external fins thereon extending substantially vertically between the headers, adjacent .tubes being spaced sumciently so that the fins thereon do not overlap, said headers and said heat exchange tubes being in direct contact with the main body of material within the tank, the longitudinal fins on said heat exchange tubes providing substantially unobstructed paths for the fiow of the material within the tank along said fins and tube in vertical directions, an upper connecting pipe and a lower connecting pipe connected to said headers respectively and extending laterally from said headers through the wall of said tank, and fittings for said upper connecting pipe and said lower connecting pipe, each of said fittings making sealing engagement between its respective pipe and the wall of the tank.

2. In combination with a generally cylindrical tank adapted to contain a commodity to be heated, a plurality of circumferentially spaced heaters within the tank, said heaters being spaced from the side wall and bottom thereof, the heaters being small as compared to the tank, each heater comprising an annular upper header and an annular lower header and a plurality of vertically disposed heat exchange tubes having longitudinal external fins thereon extending between said headers, adjacent tubes being spaced sufliciently so that the fins thereon do not overlap, said headers and said heat exchange tubes being in direct contact with the main body of the commodity within the tank, the longitudinal fins on said heat exchange tubes providing substantially unobstructed paths for the flow of the commodity within the tank along said fins and tube in vertical directions, an upper connecting pipe and a lower connecting pipe connected to said upper and lower headers, respectively, said upper and lower connecting pipes extending laterally through the wall of said tank, fittings for said upper and lower connecting pipes for making leak-proof connections between said pipes and the wall of said tank and for connecting said pipes to upper and lower external connecting pipes respectively, and manifolds disposed on the exterior of said tank and connected to said upper and lower exterior connecting pipes.

JOHN W. BROWN, JR.

References Cited in the file of this patent UNITED STATES PATENTS

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