US2232272A - Tubular heat exchange element - Google Patents

Description

Feb. 18, 1941. w. RIEGER TUBULAR HEAT EXCHANGE ELEMENT Filed Oct. 24. 19:9

INVENTOR w/z HELM 75427? Patented Feb.18, 1941 1 2,232,272

UNITED, STATES PATENT OFFICE Wilhelm Rieger, Kassel-Wilhelmshohe, Germany, assignor to The Superheater Company, New York, N. Y.

Application October 24, 1939, Serial No. 300,941 In Germany October 12, 1938 3 Claims. (01. 257-254) The present invention relates to improvements pipes l3 and [4 may be joined by well known in tubular heat exchange elements such as those methods so as to form a breeches piece l5. Then utilized in superheaters. The invention consists instead of closing the end of the breeches piece essentially in providing an element made up of as is done to fabricate a conventional type of 5 a pair of parallel pipes connected for serial flow superheater element the tubes I1 and 20 are 5 by a return bend with an extension in the nature joined as described above. The outer end of of a Field tube. tube 20 may be closed either before or after join- The invention will best be understood upon ing it to the breeches piece. To extend the reference to the following detailed description amount of heat transfer surface in an existing when read in conjunction with the accompanyheat exchange element made up of parallel pipes 10 ing drawing in which connected by a return bend, the end of the re- Fig. 1 is a vertical sectional view through part turn bend is cut off transversely and the tubes of a boiler flue having therein a tubular heat exl1 and. 20 then connected as described above. change element embodying the invention; What I claim is: Fig. 2 is a similar horizontal view, and l. A heat exchange element for use in a boiler Fig. 3 is a cross sectional view on the line 3-3 flue comprising; a pair of parallel tubes; an openof Fig. l ended breeches piece connecting said tubes at the In the drawing the numeral l0 designates part ends thereof that are adapted to be located withof a boiler flue having one end connected to a in the flue; a tube having one end extending flue sheet ll. Mounted in the flue l0 so as to through said breeches piece into one of said pipes 20 be exposed to the heat of gases travelling thereand so joined thereto that its interior forms a through is a superheater element designated as continuation of the fluid passage of said pipe, a whole by the numeral I2. The element l2 consaid tube being smaller in cross section than the sists of a pair of parallel metallic pipes I3 and I4 opening in said breeches piece and projecting connected by a breeches piece l5. Instead of befrom the latter; a second tube closed at one end 25 ing closed to form a return bend, as in a consurrounding the projecting portion of said first ventional looped element, the breeches piece 15 tube and joined at its other end to said breeches has an opening it at its end. A tube I! having piece about the opening in the end thereof, said an external diameter smaller than the cross secsecond tube being in communication with the intion of opening Iii (so as to leave an annular pasterior of said first tube and being of larger di- 30 sage) extends therethrough and into the pipe l3. ameter to form a passage between said tubes in In joining the tube I? to the pipe l3 its end communication with the interior of the other of portion is scarfed and brought to a red heat said pipes via the space between said first tube before inserting it into the pipe Hi. The tube and breeches piece and the interior of the latll projects a substantial distance beyond the ter. 35 end of the breeches piece l5 and. is surrounded 2. A heat exchange element for use in a boiler by a larger concentric tube 20 suitably closed at flue comprising; a pair of parallel tubes; an its outer end. Tube 20 is joined to the breeches open-ended breeches piece connecting said tubes piece 15 about the Opening in its the end at the ends thereof that are adapted to be 10:-

of the tube 20 preferably being welded to the Gated Within t flue; t having one end 40 metal at the PehpheP-Y of the o'pemng Spac tending through said breeches piece into one of mg 3 3 2 5?? be tack weld said pipes and so joined thereto that its interior fi i g g igg g g 1 forms a continuation of the fluid passage of said ys pipe, said tube being smaller in cross section than 4o with the annular space 22 between the tubes ll the 0 em said breeches iece and mm and 20. As shown herein, this is brought about f p 1 p p 1e 1 g by making the tube 20 of greater length than the mm tube clpsed at p end projecting portion of the tube surrounding the pro ecting portion of said first when the element is employed as a Superheat tube and oined at its other end to sa1d breeches piece about the opening in the end thereof, said 50 er tube, steam flows through the pipe IS in the direction of the arrow and thence through tube second tube bemg longer than sa1d first tube so H, the ann lar space 22, th space between tube that their interiors communicate and being of H and the wall of breeches piece l5 and from l r me r th n said first tube to form a the latter into the pipe l4. passage between said tubes communicating with In constructing new elements of this type the the interior of the other of said pipes via the 55 said pipes and having its end so joined to the latter that the interiors of said pipe and tube form a continuous fiuid passage, said second tube being smaller in diameter than the opening in said ,breeches piece and projecting through the 5 latter to a point adjacent the closed end of said first tube so that the interior of said one pipe conm'iunicates with that of the other pipe via said second tube and the space between it and the first tube.

WILHELM RIEGER.

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