US2402209A

US2402209A - Support for finned tubes

Info

Publication number: US2402209A
Application number: US542738A
Authority: US
Priority date: 1944-06-29
Filing date: 1944-06-29
Publication date: 1946-06-18
Anticipated expiration: 1963-06-18

Description

A. J. RYDER SUPPORT FOR PIHNED TUBES June 18, 1946.

Filed June-29, 1944 2 Sheets-Sheet 1 H M Rm & m .2 E 1 m M v m w M M m w. \m w R v um l 1 q R E Q N U Q g ATTORNEYS 3mm 18, 1946. J RYDER 2,402,203

' SUPPORT FOR Human TUBES Filed June 1944 2 Sheets-Sheet 2 Q3 i a: I INVENTOR ANTHONYJIR R ATTORNEYS Patented June I8, 1946 SUPPORT FOR FINNED TUBES Anthony J. Ryder, Masslllon, Ohio, aoslgnor to The Griscom-Russcll Company, New York, N. Y.. a corporation of Delaware Application June 29, 1944, Serial No. 542,738

Claims. -(Cl. 257- 2sz) This invention relates to supports for finned tubes and more particularly concerns improved means for forming a support for tubes having circumferentially extending fins on the surfaces thereof,

Many heat exchangers and related apparatus in which heat is transferred between substances employ tubes with fins .on their external cylindrical surfaces. Such fins accelerate the rate of heat transfer to or from the material in or flowing through the tube. One widely used form of finned tube employs fins extending circumferentially around the surface thereof, the fins comprising either separately spaced discs or the ad- .iaoent turns of a continuous fiat helical coil. Pinned tubes of this type are frequently disposed horizontally in he-..t exchanger structures with their opposite ends connected to headers or other ducts or parts, and due to the length of the tubes, they require mechanical support intermediate their ends. The fins on many of such tubes are formed of non-ferrous metals such as copper and are of comparatively thin gauge. The individual fins do not have sufiicient strength or rigidity to permit direct attachment of a supporting element thereto.

Flnned tubes of the type described have been supported by removing the fin structure from a section thereof and clamping the bare tube length thus exposed directly to a supporting element. This is unsatisfactory in that the removal of some fins usually damages adjacent fins, and where the fins comprise turns of a continuous helically wound strip, removal of a section thereof leaves loose or inadequately secured ends which must befixed to the tube by special means to prevent unwinding of the remaining fin turns. The positioning of a supporting band around the periphcries of a plurality of fins has heretofore been considered impractical because welding or like joining operations which appeared essential to provide a, sufficiently rigid attachment heats the non-ferrous metal forming the fins to a temperature at which it is undesirably weakened.

With the above and other considerations in mind, it is proposed in accordance with the present invention to provide an improved finned tube structure incorporating a support engaging element which is rigidly secured to the finned tube without removal of fins therefrom and without 2 bent around the fin edges with its ends in substantial engagement, the juncture of the ends of the bandis disposed over the key element, and a welded joint unites the ends of the band'and secures the band to the key element.

In describing the invention in detail, reference will be made to the accompanying drawings in which an embodiment thereof has been illustrated. In the drawings:

Fig. 1 is a sectional view of a. finned tube heat exchanger unit employing tube supporting means embodying the invention;

Fig. 2 is a sectional view taken along the line 2-2 of Fig. 1 and viewed in the direction of the arrows;

Fig. 3 is a plan view of 9, portion of the tube supporting structure of the unit shown in Figs. 1 and 2:

Fig. 4is an elevation, on an enlarged scale, showing a portion of a finned tube with the support engaging band of the invention thereon;

Fig. 5 is a end view of the structure shown in Fig. 4;

Fig. 6 is a sectional elevation of a modified form of tube supporting means embodying the invention, taken along the line 6-8 of Fig. 7 and viewed in the direction of the arrows; and

Fig. 'lis an end elevation of the structure illustrated in Fig. 6.

In Figs. 1, 2 and 3 of the drawings, there is illustrated a known form of heat exchanger unit comprising a plurality of elongated tubes 8 suitably connected at their opposite ends to an inlet header 9 and an outlet header Ill. The tubes 8 carry circumferentially extending radially pro- Jetcing fins H on their outer surfaces. In the illustrated embodiment. the fins H are of the type formed of a flat strip -or ribbonhelically weakening the fin structure. More specifically,

the invention contemplates the provision of a support incorporating a band surrounding and contacting the peripheries of a plurality of adjacent circumferentiaily extending fins, and an element in the nature of a key fixed to the band and extending through notches or openings in the adjacent fins whereby the band is rigidly locked to the fins. In a preferred embodiment of the iiiivention, the band is formed of a piece of metal wound edgewise about the tubes. Other known forms of circumferentially extending radially projecting fins may be used. In accordance with known practice, the fins l I are preferably formed of copper, an alloy containing copper or some other non-ferrous heat conducting metal.

The headers 9 and ll) of the unit are connected by side channel members I! and IS, the opposite ends of which are respectively bolted to the opposite side faces of the headers 9 and Ill as illustrated at H and I. A transverse support is provided substantially midway between the headers 9 and Hi. In the illustrated embodiment, this structure comprises an upper angle bar it and a lower angle bar II. The bars l6 and I! are secured respectively between the upper and lower edges of the channel members I! and it.

As shown inFig. 1, plates l8 and 19 are respectively welded or otherwise secured to the opposite ends of the bars l6 and I1, and bolts 20 and 2| connect these plates to the plates 22 and 23 welded to the upper and lower edges through the tubes.

. band 30.

of the channel members 12 and i3 Vertically extending plates and 25 are respectively seopposite ends of each of these-strips pass through v c,

slots 28 in the plates 24 and 25. The tubesz-g 8 of successive horizontal rows are disposed in staggered relation and the corrugationsof the

strips

26, 21 and 28 are similarly staggered to,.-';.-; conform to the circular "I shape esasd afl wn is-= s-. -.1;-

t shq db ide to x ia n. u ibe i n la m a 's ashell, of um nt-a i mb r or mass e-m nd that il passed through the shell oven the finned tubes 8 tforg-vheat exchange with --;the, -'fiuid passing Referring now more-particularlytothe sup-f ort engagin structure, each of the finned tubes J is surrounded by a band 88 extending around y and contacting the peripheriesof anplurali'tyil cf adjacent fin turns II. One or more of such?" bands may be. provided .'on'- each t and-,in the disclosed embodiment the bands 80: on the several tubes 8 are alldisposed substano tiallymidway between the tube ends and'lri li i 'with the bars .18 and i1 and the

corrugated strips

28, 21 and 28 of the supporting struc-v ture. The bands 38 are thus. disposed between the; peripheral edges of the tube fins ll, andthe supporting elements for'these tubes. Each bandjil' is formed. of metal and; preferably of ferous metal. Each of the fin turns ii con-= tasted by the band 30 has a notch 3i formed injts periphery. e e f shown in'Figfii, the notches 8i may be formed by bending a short section of the fin metal laterally to a position substantially V at right angles to the fin. The notches 8| in theadjacent fin turns H are preferably aligned 4 longitudinally of the tube. a i

A metallic strip 32, preferably formed of ferrous metal, is disposed in the aligned notches 3| of the adjacent fin turns ll engaged by the The strip 82 preferably has such cross sectional dimensions as to closely fit the notches 8| withits outer surface substantially flush with the peripheries of the fin turns and so, substantially engaging the inner surface of the band 88, as shown in .Fig. '5. The band was formed of a piece of metal bent to circular form with its opposite ends 83 and 34 sub stantially in ensagement but] slightly spaced apart. The juncture between the ends .88 and St ci ,the b Win42- -The baud I0 le 5 -me welded joint and 88 is disposed to overlie the is secured to the strip 32 by suit-f In the disclosed embodiment, a "is formed which both unites the; {Sand 84 of the ba' 38 and secures viiii th ,bandto the strip 82. I a I ,.;.With -the arrangement described, the band 38 rmly ;securecl t o the finned tube 8 in m er that. t y sh .or he tube wthe vsupportingstructure is distributed over a plurality of turns: ll Rslative 'turn-" ing-glnpvement between' -the band'llI and the. finn sat s pr v t b -the ri 2 1 8? I n. s snesc no c es! m thes -fisher -.e' nat res it; bans i andof the finned 5 4 the strip 32 are formed of ferrous metal, the welded joint "may be formed without heating ez nemie qu zmei at =..-t Deitaturehig'lnenough tozzwfeakenfihe This results from the improved arrangement described in which the strip 32 lies between the welded joint ufl and the fins II. The bands niay engag'evarious forms of supporting structures m i m 1. 2 Eor t enarnpie, as illustrated in Figs. 6 he.;-bandsj0.'=1nay be disposed in circular ina transverse plate 31 through Itclainr;

1. In a device of the character described, in mhina qn. sam a h i stc cumi rs teli ifiisfl na hro t blind Surroundingfsjaid? finned tube inengagenient' with the peripheries of. a. pluralit'yofi'the fins. said fins having -openings thereinfan element disposed insaidfin openingsandsecured .to said band and a'tiil')e'js ip'nofrtv engaging the outer'surface of said ,band.c.-c H

2. Illfl device offthe character described, in combination, a tubehaving'Icircumferentially extending spaced fins-.thereon,'.a band surrounding, said finned tube, in engagement with the peripheries'of a plurality of the fins, said fins having notches in their peripheral edges substantially aligned longitudinally of said tube, an'. element disposed .in said notches and secured to] the inner surface of said band and a igube supl orten gasingthe outer surface of said 3; In. a device "or the character described, in

combination, a, tube having a plurality of .circumferentially extending spaced fins thereon, a band comprising a piece of metal bent around said tube with its ends in substantial engagement and its inner surface engaging the peripheries of a plurality of adjacent fins, said fins having alignednotches in their peripheral edges, a strip of metal disposed in said aligned notches and engaging the inner surface of said band at the juncture of. the ends of the metal piece forming said band, a welded joint uniting the ends of said-band and securing said strip to the saiddband and'a tube support engaging the outer surface of said hand.

4. In a'device of the character described, in

combination, an elongated tube having circuml ferentially extending radially projecting fins on F its outer surface, a band surrounding said tube with its innersurface engaging the peripheries ofa plurality of said fins, said fins. having notches intheir peripheries, a strip disposed in said notches adjacent the inner surface of said band," means securing said strip to said band and a tube support engaging'the outer surface of said band. t, h I

5. In a device er. the character described, in

combination, an elongated tube having circumferentially extending radially projecting fins on its outer surfaces. metallic band surrounding said tube with its inner -surface engaging the peripheries of a plurality of said fins, said fins having notches intheir. peripheries, a strip of metal disposed injsaidnotches with its outer surface adjacent the inner surface of said band, a welded joint'betweensaid strip and said band and a ltub'ejsupport'extending transversely of said. tube' and en gaging the'outer surface of saidban'd.

,snmonrrarnna.