US2345257A - Tube support - Google Patents

Description

TUBE SUPPORT Filed Nov. 29, 19'41 4 sheets-sheet 1 1 1 ai I 1 1 1 5 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 i 1 1 1 1 l I 4 Sheets-Sheet 2 Ely/77201157 [[IllI TUBE SUPPORT Filed NOV. 29, 1941 W. C. HENSEL EVAL Mmh 2s, 1944.

March 28, 1944.

w. c. HENsEL ETAL 2,345g257 TUBE SUPPORT Filed Nov. 29, 1941 4 Sheets-Sheet 5 March 28, 1944 w. c. HENSELYETAL l 2,345,257

TUBE SUPPORT Filed NOV. v29, 1941 4 Sheets-Sheet 4 cil Patented Mar. 28, 1944 v 2,345,257 TUBE SUPPORT walter c. Hensel and Lev A. Mekler, Chicago, nl., assignors to Universal Oil Products Company, Chicago, Ill., a corporation of Delaware Application November 29, 1941, Serial No. .4.2.1,019

12 Claims. (Cl. 122-510) The invention relates to supporting means for a substantially vertical bank of horizontally disposed heating tubes. The features of the improved type Aof supporting means provided by the invention are particularly advantageous as applied to the-tubular iluid conduits of Oil heaters, boilers and the like, which tubes are subjected to high furnace temperatures and are of suillcient length in the heating zone to require one or more supports intermediate their ends.

The invention provides both intermediate and end supporting means for a tube bank of the nature above mentioned, as well as means for sealing the tube header compartment of the furnace from the heating zone thereof in which the intermediate tube supports are disposed.

In supporting a vertical bank of horizontally disposed tubes which traverse a high temperature heating zone in a furnace and are of sufcient length to require intermediate supports disposed within said heating zone, it is convenient to construct the intermediate supports oi.' metal or metallic alloy which retains good strength at the temperatures employed in the heating zone and is otherwise capable of withstanding oxidizing conditions and the like which may be encountered, so that the supports may be left. bare or uninsulated and are exposed on all sides to the temperature conditions prevailing in the heating zone. The end tube supports, on the other hand, conventionally comprise tube Ysheets which serve as a partition between the heating zone and the unheated compartments of the furnace in which the tube headers or return bends are disposed. The end tube supports are, therefore, subjected to the high temperature conditions prevailing in the heating zone on only one side or, in some instances, are insulated on the heating zone side in order that they may be constructed of less expensive material than the bare intermediate supports andvto prevent excessive heat loss therethrough. In service such an arrangement brings about differential expansion and contraction' upon heating and cooling between the intermediate supports and the end supports. As the furnace is brought up to temperature, the intermediate supports, being subjected to a higher temperature than the end supports, expand a greater amount and become longer than the end supports. If the tube bank is suspended, (l. e., with the supporting means xed at the top and free to expand in a downward direction) the members of the intermediate supports upon which the tubes rest when the latter are cold will, when heated, expand away from the tubes and leave them unsupported. If the tube bank is supported from the bottom (i. e., the supporting means fixed at the bottom and free to expand in an upv er compartments and allowing the tube to oat in the end tube sheets by providing the latter with elongated tube openings. However, such an arrangement brings aboutv another undesirable condition due to the lack of supporting means at at the end of the tubes and the weight of the return bends or headers, the unsupported ends of the tubes and the headers being carried by the intermediate supports nearest the tube sheets and giving a cantilever action which tends to bow the tubes upward between the end-most intermediate supports. This may bring about penna--i nent distortion to the tubes and render them diiiicult to clean, as well as setting up undesirable stresses in the tube walls. This also renders any intermediate supports, other than those nearest the tube sheets, of little or no utility during normal operation of the heater so that the two end-most tube supports must be sufficiently strong to carry substantially the entire weight of the tube bank.

' The improved .supporting means provided by the invention obviates all of the diculties above.

mentioned.' We utilize bare or uninsulated intermediate tube supports of suitable high-temperature-resistant metal or alloy and of special construction which prevents springing of thel tubes from the intermediate supports, but permits the tubes to be lifted onto and from the intermediate supports in assembling the tube bank and in replacing worn out or damaged tubes. We also employ tube sheets between the header compartments and the heating zone which are preferably insulated on the heating zone side and` are provided with elongated tube ports which permit free upward and downward movement of the tubes at the tube sheets, the latter functioning as partitions which separate the heating zone from the header compartments. We utilize the headers or return bends, which connect the adjacent tubes of 4the bank at their opposite ends,

` by the lin in the accompanying diagrammatic drawings. s

In the drawings, Figure 1 is a sectional elevation of a. portion of a heater showing one end and an intermediate' portion of a tube bank supported as provided by the invention.

Figure 2 is a view taken along line- 2-2 in Figure 1, showing some of the lowermost tubes of the bank in cross section and showing a front elevation of the lower end of one of the intermediate tube supports.

Figure 3 is a view of a portion of. the tube bank at an intermediate support and is taken along line 3 2 in Figure 2l Figure 4 is an enlarged detail showing, in front elevation, a portion of the Vintermediate support v' illustrated in Figures 1, 2 and 3. v Figure 5 is a side elevation of that portion of the support iiiustrad in Figure 4, with the impe 6 omitted.

Figure 6 is a sectional elevation illustrating return bends such as provided by the invention for use in a bank comprising adjacent .vertical rows of staggered tubes with the adjacent tubes in opposite rows connected in series. This section is taken along a plane winch cuts through the tubes adjacent the return bends, as'indicated by the line 6--6 in Figure 1. y

Figure '1 shows an enlarged detail of one specinc form of linkage means joining two adjacent return bends such as provided by the invention.

Figure 8 is a view taken from the plane indicated by the line 8 8 in Figure 7.

Figure 9 is a sectional elevation similar to that of Figure 6 butillustrating return bends such as provided by the invention as used for connecting adjacent. superimposed, horizontal tubes in a vertical row. This section. is taken. as in Figure Figure 1 0 shows an enlarged detail of an alterwhich are insulated in the heating zoneras indicated at 23, and separate the latter fromf-the 'I he entire furnace structure is supported on a suitable foundation y header compartments 25.

2 I The heater may be fired in any desired manner.\ The 'firing means'do not comprise a novel part of the invention, and is not illustrated.

Referring particularly to Figures 2 to 5 inclusive, the intermediate tube support I, -as here illustrated, comprises a substantially I-shaped member which forms the main body of the support, having opposite flanges joined by an open.-

work web. Along the outer face 'of each of the flanges, brackets 4 and' 5 are provided at spaced intervals along kthe length of the flanges. The vertical distanceV between corresponding portions of adjacent brackets 4 on the same flange corresponds to the vertical center to center distance between the vertically aligned, horizontally disposed tubes Iiv in each row thereof disposed on opposite sides of the support, as illustrated. 'I'he vertical distance between corresponding portions of the adjacent brackets 4 on the opposite flanges, corresponds to half the vertical center to center distance between the adjacent tubes -in each row.

The same applies to the distance between the corresponding portions of brackets 5. The adjacent brackets 4 and 5 on the same flange are complementary, the tubes 6 resting upon the pper curved surface of brackets 4, and brackets serving as anchorsv for the upper ends of the substan tially semicircular members 1, the lower ends of which are anchored in the supporting brackets 4.

Members 1, which serve to prevent tube 6 from springing from the supportingstructure due to any tendency of the tubes to bow when heated, may be tubes or solid rods of circular cross-section curved Ato a diameter somewhat larger than the outsidediamgser of tube 6. The members I each denne slighuy 'more than half a circle so 4 and i, they cannot be forced therefrom by the 6, along a plane which cuts through the tubes adjacent the return bends.

nate form of linkage means between two adjacent return bends.

Figure 11 represents a view taken from the piane indicated by the une li-i i in Figure io.

Figure l2 is a sectional view of a portion of the tube sheet at one end of the heater. 'Ihe section being taken [along a plane which cuts through the tubes adjacent the return bends -as indicated |2--I2 in Figure 1. 1 Figure 3 is a sectional view taken along line Il-Ilin Figure 12.

Referring to Figure 1, the tubular fluid conduits s are supported `at spaced ppints within the heating rane of the furnace structure by intermediate supports I. When the` furnace is fired,

the linkage members I I and AI2 attached to the return bends Il take up the`support of the opposite ends of the hibes. The intermediate supports and the return bends as well-asumel tube sheet Il are suspended from suitable members 2l as shown. The heating'wne of the lateral thrust of tubes 5 when the latter tend to bow outward from the support. However, the form of the brackets and members l make the latter readily detachable from the brackets when it is desired to place a tube on or remove it from the supporting structure. by rotating member 'I in the direction indicated bythe arrow shown with the solid line in Figure 4, forcing'its upper end farther into opening 9 y I of barcket 5x and releasing its lower end from the opening 8 in bracket 4. Then, by turning member 'I'to .the approximate position indicated by the dotted lines in Figure 5 sc that its lower end clears bracket 4, it may be rotated 'in the opposite direction, indicated by the dotted arrow in Figure 4 until its upper end is free of opening l in bracketl l, thus releasing member 'I from-the brackets and permitting tube 6 to be lifted upward and outward from the support, the distance between the outer ends of adjacent brackets 4 and l being somewhat greater than the outside diameter of the tube. 1

Referring now to Figures 6, 'I and 8 of the drawings, the-'tubes 6 terminate inthe return bends Il. Angularly attached to one side ofthe Vreturn bend is a single lug II and to the opposite side of the return bend a forked, lug or .two parallel lugs. I2 are attached and-so arranged ythat the n single lug on the adjacent return. bend-is received structure is enclosed by refractory sidewalls, not V- shown inthis view, alefractory roof22.- a refractory oor 24 and tube sheets, such as shown at Il, '*15 between the lugs or forks I2. "ier'tictillvy elQngated holes Il and Il'4 are through lugs II -andIl respectively 'to receive' `a 'Ihis is accomplished which is of substantially smaller diameter than the length of said holes and is retainedv in position by cotter keys or by any other desired means. The vertical center to center distance between the holes in the lugs on opposite sides of the return bend is equal to the center to center distance between the vertically aligned horizontally disposed tubes 6, as indicated by the dimension A in Figure 7. The difference in the diameters of the pin I4 and the vertical dimension of holes I3 and I3'v substantially corresponds to the expansion which will occur between tube centers in the intermediate tube supports, when heated, so that when the intermediate tube supports expand during heating, this difference is taken up, thereby causing the tube return bends IG to assume the support of their respective tubes and all return bends and tubes disposed therebelow. By thus supporting the tube ends when they are in a heated state, the possibility of their becoming warped or bowed is minimized, and stresses within the tube walls dueto bending are thus obviated. This also helps to decrease permanent distortion of the tubes and thereby lengthens their useful life and facilitates the removal of carbonaceous or calcarious deposits therefrom.

Figure 9 shows a linkage arrangement similar to that shown in Figure 6 except that the return bends I' of Figure 9 connect adjacent horizontally disposed tubes 6 in a vertical row thereof. The lugs II and I2' are disposed at opposite and 2B in this gure. With this arrangement, l

as in that shown Figure 7, the pins which connect the lugs on the return bends are smaller than the openings provided for the pins.

Figures 10 and .l1 show an alternative form of linkage means wherein the lI-shaped member I8 engages the slots i1 and I1 in the return bend extensions or lugs I5 and I5 respectively on the return bends I0" when the intermediate tube supports expand. The members I6 and slots i1 and I1 are of such relative size that the return bends are loosely connected when the tube bank is cold, the slack being taken up when the intermediate tube supports expand so that the return bends act as end supports for the tubes. 'Ihis form of linkage arrangement may also be substituted, when desired, for that shown in the return bend arrangement of Figure 9.

Referring to Figures 12 and 13, the tubes 6 extend through the vertically elongated openings 26 in the tube Sheet I8. Adjacent the outer surface of the tube sheet the tubes are encompassed by the closure plates- 21 which are retained in slidably movable relationship to the tube sheet by washers 28, the tubular spacing members 29 and the bolts 30 which engage the tube sheet and pass through the vertically elongated central openings 3| in plate`21. The tubes and closure plates are thus free to move up and down within the limits necessary to accommodate longitudinal expansion and contraction of the intermediate supports, and the tubes are free to expand and contract longitudinally through the tube openings in lthe tube sheets and closure plates without moving the latter from its position of sliding engagement with the tube sheet. Using this feature of the invention, it is possible to allow for the longitudinal expansion of both the intermediate supports and the tubes themselves and still maintain a substantial seal between the tube heater compartment and the heated portion of the furnace.

We claim as our invention: p

1. In a heater for fluids having a bank of tubular fluid conduits disposed within a heated zone of the structure and provided at their ends with terminal fittings which connect adjacent tubes of the bank and are disposed outside said heated zone, means comprising bare metal members disposed within said heated zone for supporting said tubes intermediate their ends, means comprising metal tube sheets insulated from said heated zone for separating the latter from that zone of the structure in which said terminal ttings are disposed, and means loosely interconnecting said terminal fittings when the intermediate supports are cold and which tighten to support the tubes at their ends when the intermediate supports are hot.

2. In a heater for fluids having a bank of tubular uid conduits disposed within a heated zone of the structure and provided at their ends with terminal ttings whichconnect adjacent tubes of the bank for the flow of fluid therethrough and are disposed outside said heated zone, means com-l prising bare metal members disposed in said heated zone and freeat. one end, for supporting the tubes intermediate their ends, means loosely interconnecting said terminal fittings when the intermediate supports are cold and which tighten to support the tubes at their ends when the intermediate supports are hot, and means comprising metal plates provided with openings through which the tubes extend and insulated from said heated zone, for separating the latter from that zone of the structure in which said terminal fittings are disposed.

3. The structure' defined in claim 2 wherein said separating means and saidend-supporting means are constructed and arranged to permit expansion and contraction of the tube bank and of said intermediate supporting members.

l 4. In a heater for iluids having a bank of super-imposed, horizontally disposed tubular fluid conduits extending through a heated zone ofthe structure and provided at their opposite ends with terminal ittings disposed outside said heated zone and connecting adjacent tubes of the bank for the flow of luid therethrough, means comprising tube sheets provided with openings larger than the tubes and through which said tubes extend for separating said heated zone from that zone in which the terminal ttings are disposed, said tube sheets being insulated from the heated zone, means comprising bare metal members disposed Within said heated zone and free at one end, for supporting the tubes intermediate their opposite ends, and means on said terminal littings which loosely interconnect the same when theintermediate supports are cold and which tighten to support the tubes, at their ends when the intermediate supports are hot. l

5. The structure deiined in claim 4 wherein the last named means include lugs on said terminal fittings and links connecting adjacent ttings at said lugs.

6. The structure dened in claim 4 wherein said intermediate tube-supporting means comprise elongated members having verticallyspaced brackets between which the tubes are received and members spanning adjacent brackets and detachably secured thereto for restraining springing of the tubes from between said brackets. l

'1. The structure dened in cham 1 wherein the intermediate tube-supporting means comprises an elongated metal member, pairs of brackets on said member spaced apart to permit the passage of a tube therebetween, and an auxiliary member spanning the distance between each pair of said brackets and detachably secured thereto in such a manner as to prevent springing of the tubes from between the brackets when said aux iliary members are in place.

8. Thestructure deiined in claim 1 wherein the intermediate tube-supporting means comprises an elongated metal member anchored at one end and free at its opposite end to permit longitudinal expansion and contraction thereof, supporting ybrackets for the tubes disposed on said member at spaced points along its length, auxiliary brackets disposed on said member between and spaced from said supporting brackets, and other auxiliary members spanning the distance between the supporting brackets and the adjacent auxillhang adapted to nt within said openings and the shape, size and curved contour of said openings and retaining members being such that the latter resist outward bowing of the tubes but are detachable from the brackets by a combination of motions including partial rotation of the retaining members. F

10. Supporting means for the ends of tubes in a bank of substantially horizontal tubular fluid conduits, said means comprising terminal ttings on said tubes interconnecting `adjacent tubes of the bank for the flow of fluid therethrough, and means for detachably interengaging adjacent fittings comprising lugs on said fittings provided conduits, said means comprising terminal ttings iary brackets and detachably secured thereto in such a manner as to restrain springing or the tubes from between said brackets.

9. In combination with a bank of substantially horizontal tubular fluid conduits disposed within y being adapted to receive and retain the opposite` ends of an elongated rigid member of curved contour spanning the distance between said pair of brackets, and detachably secured to the latter to retain one of said tubular members therebetween, the brackets being provided with openings therein of cu'rved contour corresponding to that of the ends of said retaining member, said ends with regsterable openings therethrough, and removable pins of smaller size than said openings and receivable thereinfor interengaging adjacent fittings at said lugs.

, 11. Supporting means f or the ends of tubes in a bank of substantially horizontal tubular fluid on said tubes interconnecting adjacent tubes of the bank for the flow of fluid therethrough, and means for detachably interengaging adjacent fittings comprising lugs on said ttings provided with slotted openings therein and links extending between and detachably .engaged with the slotted openings in the lugs of adjacent fittings.

12. Supporting means for the ends of tubes in a bank of substantially horizontal tubular fluid conduits, said means comprising terminal fittings on said tubes interconnecting adjacent tubes of the bank for the flow of fluid therethrough, and means for detachably interengaging adjacent fittings comprising lugs on said fittings provided with slotted openings therein and links. extending between and detachably engaged withB the slotted openings in the lugs of adjacent fittings, said linksy and openings being of such form and .relative size that the adjacent fittings are loosely engaged when the tube bank is cold and tightly engagedv when the tube bank is hot.

WALTER c. HENSEL. LEV A. MEKLER.

Images