US3026858A - Tube support - Google Patents

Description

March 27, 1962 K. W. FLElscHER 3,026,858

TUBE SUPPORT Filed sept. 2s, 1959 ATTORNEY.

T In INVENTOR.

United States Patent 3,926,858 Patented Mar. 27, 1982 fhce 3,026,858 TUBE SUPPORT Kurt W. Fleischer, Philadelphia, Pa., assignor to Selas Corporation of America, Dresher, Pa., a corporation of Pennsylvania Filed Sept. 23, 1959, Ser. No. 841,796 8 Claims. (Cl. 122-510) The present invention relates to furnaces for heating fluids iowing through tubes, and more particularly to a support for holding the tubes in such a furnace.

In tube heating furnaces of the type used in the petroleum and chemical industries the tubes are frequently from thirty to fifty feet in length. These tubes must be supported in the furnace in such a manner that they will not sag or become distorted with the heat, and in such a manner that they are permitted to expand and contract with changes in temperature.

It is an object of the invention to provide a means for supporting a tube in a furnace which will retain its strength under the high temperatures that are encountered, and one which will permit expansion and contraction of the tube without damage thereto.

In carrying out the invention, vertically extending, water-cooled supports are located at spaced points along a furnace. The supports are such that horizontally extending tubes are located at fixed levels in the furnace, with the tubes being free to expand, without damage to themselves, as a result of temperature changes.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

In the drawings:

FIG. l is a section through a tube heating furnace showing the support of the invention,

FIG. 2 is an enlarged view of one of the tube supports,

FIG. 3 is a View taken on line 3 3 of FIG. 2,

yFIG. 4 shows a modified form of tube support, and

FIG. 5 is a view taken from the right of FIG. 4.

Referring to the drawings, there is shown in FIG. 1 a section through a tube heating furnace similar to that disclosed in Hess Patent 2,638,879. This furnace includes buskstays 2 that are used to support the structure of the furnace which may be built of refractory material backed up by sheet metal in accordance with ordinary furnace practice. The furnace is shown as including side walls 3 that have located at spaced points in the burners 4. The upper portion of the furnace terminates iu the stack 5. Tubes 6, through which the Huid to be heated ows, extend lhorizontally in a direction perpendicular to the plane of the drawing. The ends of the lengths of tube are usually joined by return bends to form a continuous, serpentine tube through which the fluid to be heated ows back and forth across the length of the furnace from the top to the bottom thereof. Normally the return bends at one end of the tube bank are held stationary so that as the tubes expand and contract due to changes of temperature in the furnace chamber, they will move toward and from that end of the furnace. With a conventional arrangement of this type, it is necessary to provide means for supporting the tube lengths in parallel relation as they extend horizontally through the furnace, and to provide some means that is capable of permitting movement of the tubes without damage to them.

The tube support with which this invention is particularly concerned comprises a pair of ver-tically extending, parallel pipes 7 that are supported by and communicate at their lower ends with a supply manifold 8 through which a cooling 'uid, usually water, is forced. The upper ends of the pipes 7 bend outwardly through the upper walls of the furnace, as shown in the drawing, and are connected to suitable discharge manifolds, not shown. These supports are located at spaced distances along the length of the furnace so that the tubes 6 are supported along their length at frequent enough intervals so that they will not sag during the heating process. For normal furnace practice these supports would be about eight feet apart.

Referring to FIGS. 2 and 3 it will be seen that the pipes 7 can be covered with insulation 9, if it is so desired. Generally this is done in order to prevent too much heat from the furnace being carried away by the cooling uid ilowing through the pipes.

The pipes '7 are provided with horizontally extending and aligned openings through which are inserted sleeves 11 with the ends of the sleeve being welded to the edges of the openings in the pipe to form a liquid tight joint between the two. 'Ille sleeves form vertically spaced, aligned passages through each pair of which a shaft in the form of a bolt 12 extends. Each shaft has on it, between pipes 7, a tube supporting roller 13 that has a reduced bearing portion 14. Spacers 15 may be, and preferably are, used between the inner ends of sleeves 11 and the roller 13 in order to maintain the holler in the center of the shaft. These shafts and the rollers thereon are located at spaced points along the pipes 7 to support the tubes 6. If the tubes 6 are live inches in diameter, the supports can be placed on ten inch centers, th-us giving plenty of room between the supports for the tubes to be inserted.

With a tube support of the type shown herein, cooling fluid flowing through pipes 7 and around sleeves il, will keep these parts at a temperature suiciently low so that they will have strength enough to support the tubes in their desired locations. Since the shafts 12 extend through the water cooled sleeves 11, they will also be cooled sufficiently for them to retain their strength in the heat of the furnace. Rollers 13 will be made of a heat resisting alloy that is capable of withstanding the temperature that is encountered. The bearing portion 14 of this roller has a loose fit on shaft 12 so that as the pipe resting thereon expands and contracts, the roller will rotate with a minimum of friction on the shaft, thereby permitting the tube to expand and contract freely without the tube itself being scraped against any surface.

The embodiment of the invention disclosed in FIGS. 4 and 5 differs from that previously disclosed primarily in the manner in which the tube supporting roller is mounted between the pipes 7. It will be seen from the drawings that passages are formed in pipes 7 by rectangular sleeves 16 which extend through the pipes and which have their ends welded to openings provided in the pipes. A substantially rectangular bar 17 having cut-out portions 18 extends ybetween the parallel pipes 7 with the cut-out portions or notches resting against the lower side of sleeves 16. With this arrangement a bar 17 can be moved into position and will remain properly located because of the cut-out portions. Received on this bar, between the pipes 7, s a tube supporting roller 19 which is provided with a pair of narrow bearing portions 21 that rest against the top of the bar, which may Ihave a curvature equal to tha-t of portions 21.

In this case also the bar 17 is cooled by its engagement with sleeve 16 so that the bar is maintained at a temperature low enough for it to retain its strength. The relatively small bearing surface between the portions 21 of the roller and the upper surface of bar 17 will permit this roller to rotate freely as the tubes 6 carried thereon expand and contract.

From the above description it will be seen that I have provided a tube support consisting of parallel, vertically extending water-cooled pipes, which pipes are provided with sleeves that serve to keep the tube supporting member at low enough temperature so that its ystrength will not be impaired. In addition, the tube itself is supported on rollers that can be rotated when the tube changes in length. Since the rollers which actually support the tube are themselves not cooled to any appreciable extent, they will not have a cooling effect on the tube or the fluid owing therethrough.

While in accordance with the provisions of the statutes, I have illustrated and described the best form of embodiment of my invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit and scope of the invention set forth in the appended claims, and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

What is claimed is:

l. Means for supportingy a bank of tubes adapted to extend horizontally in a furnace chamber comprising a pair of parallel pipes extending vertically, each pipe having a plurality of vertically spaced pairs of axially aligned openings extending horizontally therethrough, a sleeve forming a horizontal passage through the pipe and received in each pair of openings, means to supply a cooling uid through said pipes and around said passages, the passages in each pipe being aligned horizontally with a passage in the other pipe, a supporting member received in and extending through each pair of aligned passages, and a tube supporting element surrounding each member between said pipes.

2. The combination of claim l in which each of said passages is cylindrical and said supporting member is a shaft, each element being a grooved roller rotatable on said shaft.

3. The combination of claim l in which each passage is rectangular in shape and each supporting member is correspondingly shaped and of a size to be received in said passages, said members being provided on their lower surfaces with notches of a length equal to the length of said passages whereby the ends of said notches will engage the ends of said passages to prevent movement of said members, and in which said element are rollers received on said members.

4. Means for supporting a tube adapted to extend horizontally in a furnace chamber comprising a pair of parallel, vertically extending pipes, each of said pipes being provided with a pair of horizontal openings with the openings in the pipes being axially aligned, a sleeve extending through each pipe and received in each pair of openings to form a passage, means to supply a cooling fluid to ow through said pipes and around said passages, a supporting member extending through said passages, an element upon which a tube is adapted to rest mounted for rotation on said member between said plpes.

5. The combination of claim 4 in which said tube supporting member is in the form of a grooved roller.

6. A tube support for use in a furnace having horizontally extending tubes comprising a pair of vertically extending pipes, means to supply a cooling fluid through said pipes, a plurality of vertically spaced pairs of openings in said pipes, the openings in each pipe being lhorizontally aligned with a pair of openings in the other pipe, sleeves forming passages extending through each pipe with a sleeve received in each pair of openings, a supporting member extending through said aligned passages, means to hold said members against axial movement in said passages Iand a tube carrying part on each member between said pipes.

7. The combination of claim 6 in which said pipes are insulated.

8. The combination of claim 7 in which each tube carrying part is a roller loosely received on a supporting member.

References Cited in the file of this patent UNITED STATES PATENTS 425,856 Brislin Apr. 15, 1890 1,645,762 Lohbiller Oct. 18, 1927 2,103,811 Davis Dec. 28, 1937 2,652,037 Lewis et al. Sept. 15, 1953 2,716,968 Hess etal. Sept. 6, 1955 FORElGN PATENTS 503,639 Canada June l5, 1954

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