US3163208A - Brace for finned tubes - Google Patents

Description

2 Sheets-Sheet l Dec. 29, 1964 R. cUzzoNE ETAL BRACE FOR FINNED TUBES Filed sept. 29, 1961 Dea 29, 1964 R. cUzzoNE ETAL BRACE FOR FINNED TUBES Filed Sept. 29. 1961 2 Sheets-Sheet 2 Fig m mwwwh United States Patent() 3,163,268 BRACE FR FINNED TUBES Raymond Cuzzone and John R. Harvey, both of Pittsfield,

Mass., assignorsy to General Electric Company, a corporation of New York Filed Sept. 29, 1961, Ser. No. 141,743 8 Claims. (Cl. 16S- 69) This invention relates to arrangements for inhibiting vibration of finned tubes of the type employed in heat exchangers.

Tubular. members having tins extending laterally therefrom are commonly employed in heat exchangers in which a liuid to be cooled passes through the tubular members and dissipates heat to another fluid, such as air passing over the outside of the tubular members. The ends of the tubular members are commonly secured to headers. One problem that frequently occurs with this arrangement is that unexpected vibrations are encountered when the apparatus incorporating the heat exchanger is placed in operation. For example, it has been found that failures occurred in finned tube heat exchangers employed on locomotive transformers when the vibration of the transformer and locomotive were more severe than was anticipated at the time the apparatus was designed. To dampen vibrations, an arrangement was required for bracing the heat exchanger tubes after the apparatus was assembled, without the necessity for removing the tubes from the headers. Although arrangements for bracing finned tubesintermediate their ends were known to the prior art, these arrangements required that the bracing structure be placed between the tubes before they were secured to the headers, or that bulky or expensive clamping arrangements be employed.

Accordingly, it is an object of our invention to provide improved arrangements for bracing linned tubes.

Another object is to provide header-attached finned tubes with braces that can be placed between the tubes without requiring disassembly from the headers.

Another object is to provide a brace arrangement for` linned tubes in which the braces are interlocked with the fins to prevent movement of the braces.

Another object is to provide a bracing arrangement for linned tubes in which clamps that act on the tubes are not '.required.

A further object is to provide bracing assemblies that are economical to manufacture yet rugged enough to withstand continual vibrations during operation of the apparatus.

Other objects and advantages of the invention will become apparent from the drawing, specification, and claims, and the scope of the invention will be pointed out in the claims.

In carrying out our invention in one preferred embodinient, we provide in Vcombination with a plurality of finned tubes arranged in parallel spaced-apart rows, a vibration damping or inhibiting means rformed as a straight and substantially iniiexible bar having a str-ip of resilient material sandwiched between hard surfaced protective facing members and interposed in wedging relation between adjacent rows of tubes. ri`he straight and stili vibration damping bar is wedged tightly between the rows of tubes to compress the resilient strip with the facing members engaging the edges of the tube fins to protect the resilient strip. To prevent lateral displacement of the damping bar, or brace, longitudinally of the tubes at least one facing member is provided with one or more positioning projections disposed to interlock with the tube fins. This resilient bracing assembly, being in the form of a straight bar with the resilient material internally built in, is adapted to be inserted between the rows of tubes after full assembly of the tubes. It requires no holding means ice other than the tubes themselves and the side panels of theV heat exchanger, i.e. no external clamping Vmeans is necessary.

' In the drawing:

FIGURE l is a schematic, partially cross-sectional, side elevational view of a finned tube heat exchanger in accord with the teachings of our invention.

FIGURE 2 is a cross sectional view taken along the line 2-2 in FIG. 1.

FIGURE 3 is an enlarged cross sectional end view of a brace assembly employed in the embodiment of FIGS. 1 and 2.

FIGURE 4 is an enlarged side view of the lower right hand corner of FIG. 2, with brace assemblies shown in cross section.

FIGURE 5 is an enlarged cross sectional end view of another embodiment of a brace assembly in accord with our teachings.

FIGURE 6 is an enlarged cross sectional end view of still another embodiment of a brace assembly in accord with our teachings.

In FIGS. l and 2, a conventional heat exchanger 10 is shown to comprise a plurality of elongated tubes 11 arranged in staggered, parallel rows. The tubes 11 are provided with iins 12 which extend outwardly therefrom generally perpendicularly to the longitudinal axis of the tubes. The tubes 11 may be secured at one end to an inlet header 13 and at the other end to anroutlet header 14. Thus, fluid which is to be cooled by passage through the heat exchanger 10 would ow into the inlet header 13 through suitable conduit means 15, thence, through the tubes 11 into the outlet header 14, and then through an outlet conduit 16. The remaining members of the fluid system are not illustrated or described because they form no part of the present invention. The heat exchanger 1li may be bounded on opposite sides by side panels 17 and 1S for the purpose of protecting the finned tubes, or for -batiiing the flow of air over the tubes.` The panels 17 and 18 may be detachably secured to the headers by bolts 19. f

It sometimes occurs that inned tube heat exchangers are subjected to vibrations more severe than those expected when the heat exchanger was designed and constructed. In such -a case, means must berprovided for inhibiting the unexpected vibrations of the iinned tubes to prevent damage thereto. To accomplish this function, we provide vibration inhibiting brace assemblies 20 that are wedged between the rows of tubes in directions transverse to the longitudinal axis of the tubes. The restraining action of the brace assemblies substantially prevents movement of the tubes at the points of contact and thereby inhibits vibration of the tubes.

Y As shown more clearly in FIGS. 3 and 4, each brace -assembly 20 may comprise a substantially inflexible U- lshaped channel member 21, made of a metal such as aluminum, in which are placed resilient means 22. The resilient means 22 may be made from a single strip of resilient material, or from strips 23 of resilient material,

such as rubber, bondedto a metal carrier strip 24. Bonding the resilient strips 23 to the strip 24 facilitates liandling by stiiening theresulting laminate and by preventing buckling of the resilient ystrips 23 Ycaused by the fric,- tion Vgenerated as they rub against the channel member 21. To protect the face of the upper strip i23 from the cutting action of the tins 12, a hard surfaced protector member 25, such as a strip of aluminum, may be provided over one face of the upper strip 23, it'being obvi-V ous that the bight portion 26 of the U-shaped channel 21 acts as a metal protector member for the opposite face of the lower resilient strip 23. As shown in FIG. 4, the ends 27 of the channel 21 maybe bevelled in order to exchanger.

3 Y facilitate insertion ofthe brace assemblies 20 between the heat exchanger tubes. y v

For proper operation 7^of our rangement, the thickness t of the resilientmeans 272, and

its protectorsshould be greater than the distance d (see FIG. 4) ,between the fins on the heat exchanger'tubes bevibrationV inhibiting ar-A tween whichthe brace assemblies are wedged; this en-y Y sures that the resilient strips 23V will ybe compressed by the wedgingy action of the protector members againstrthe Y tins to thereby inhibit vibrations.

channel sides v28 shouldjbe greater Vthan the thickness t.

K This ensures that the ends of they channels will provide projections -at 29 that extend outrof the planether-eof to overlap the tins VVon the rows between whichrthe brace assemblies are inserted, thus Linterlocking the brace assentblies and fins. This prevents the brace ,assemblies from moving longitudinally of the tubes 11 and prevents them from falling over or being shaken out of position as the apparatus vibrates. v

w VBraces can be inserted between parallel( rows of nned tubes inV horizontal, vertical, or diagonal directions. Those skilled lin the art are aware that the direction'chosen in any specific case should provide an optimum distance d between the tube insthat'is neither too small nor too large for practical applications. Thus the illustration of Vthe brace assemblies 20 extending indiagonal directions is intended -to be exemplary, and not limiting onthe scope of the invention.

Although the interlocking kaction between the tins 12 and projections Z9 prevents Vmovement of the brace assemblies longitudinally of the tubes 11, continual vibration of the apparatus could cause the brace assemblies to be jostled out of position transversely of the tubes. To prevent this, abutment means should be provided for e11- gaging ythe opposite ends of theY brace assemblies 20. AsV

shown in FIG. 2, each brace assembly contacts one of the side panels 17 'or 18 at one vof its'ends, and some of the brace assemblies contact they side panels at both ends.

VSome of the brace assemblies doV not contact both side panels, so adjustable screw-actuated abutment means 30 arev provided adjacent the top and bottom of the'heat l Each adjustable abutment` means Silmay comprise, for example, a bar 31 Vattached at either-,end

to the side panels'byV bolts 32 and nuts 33a; The bars 31, may have a pair of tapped holes therein, and bolts-34 may be threaded through the tapped holesf The ends of the bolts 34 may be journaled rotatably in abutment Amembers 35 that engages the' ends ofthe brace assemblies that do not contact the side panels. Thus, to raise or lower the `position of an abutment member 3S, the appropriate bolts 34 are rotated and thus advanced or retracted through a bar 31. Those skilled in the art will be aware that the adjustable abutment means 30 could be eliminated if both ends of each brace assembly contacted the side panels, as for example if the brace as -semblies 2t) extended vertically through the heat` ex-l changer illustrated at FIG. 2.` Y

FIG. shows another embodiment of the invention in .which a brace assembly 4d has resilient means 41 identical to the means 22 of FIG. 3 sandwiched between in` flexible T-shaped aluminum protector members dft.` The legs of the members 42 deine projections V43| which ex- 1 tend out of the plane of the protector membersto en.V gage the ns 12 on the tubular members 11-in the sameVVV way as the projections 29 onk the; Uishaped ,channelof ftheV embodiment shown `in FIGS.1-4. This locks Vthe brace assemblies 49 in` place in vthe manner previously described. i

FIG. 6 shows stillanother embodiment of the inven-V tion in which a `brace .assemblyfStl has resilient means Y 51 identical to the` means 22 of FIG. 3 sandwiched be- V.'*tween inflexible L-shaped aluminum protector members 52. One leg of each member 52 denes a projection 53 that extends out of the plane of the member for locking The width w of the dling as a single unit.

a single unit. For this reason, the embodiment of FIGS.`

1,-4 is preferred over the embodiments of FIGS. 5 and 6.

It has thus been shown that by the practice of our inven v tion, novel braces of straight elongate configuration may VKi be inserted lintermediate the ends ofthe nned tubes of tending outwardly therefrom, means secured tothe ends ,l

of said vtubes closing oli the Vspace therebetween, and a" a heat exchanger and between adjacent rows of Atubes without requiring disassembly of the tubes 4from their headers. Consequently, when unexpectedly severe vi-` brations are encountered during operation of apparatus employing a finned tube heat exchanger, our vbrace Aassemblies may be employed without unreasonable vexpense. The braces have as inherent structure thereof, projections which lock the assemblies in place, thus preventing them from displacementV lengthwise of the tubes.

This is accomplished without external clamping struc.y

ture to exert positive clamping forces on the tubes.

The elimination of the need for clamping structures en` ables our :bracing arrangement to be employed without increasing the space occupied by a heat exchanger. Our

arrangement is also economical, since it is vmade from standard, relatively inexpensive components, and is suiciently rugged in construction `to withstand the forces encountered during continualvibration of the apparatus.

It will be understood, of course, that while the forms of the invention herein shownw and described constitute preferred Vembodiments of the invention, it is not intended herein to illustrate all ofthe equivalent forms or ramifications thereof. It will also be understood that the kwords used are words of description rather than of limi- Y tation, and that various changes may bemade withoutI departing from the spirit or scope of the 4invention hereinV disclosed, and'it is aimed in the appended claims torcover allsuch changesas fall within' the true spirit and scope yof the invention.

What We claim as new and desireto secure by Letters Patent of the United States is:

l. The combination comprisinga plurality of tubes arranged in a plurality of rows, said tubes having fins exstraight and stift elongate assembly for inhibiting vibration of said tubes comprising a strip of resilient material,

hard surfaced members protecting opposite faces of saidv resilient material from being cut by the tins, and a projection on a hard ksurfaced member extending out of the plane thereof, said vibration inhibiting assembly beingl rm'lywedged between said rows of said tubes-intermediate their ends and extendingtransversely of the tubes and inf engagement withedges of Vsaid ns, said resilient mate- Y rial being ycompressed between said nhard surfaced members by their wedging action against the tube ns, and

* saidV projection interlocking with a plurality of said lins `to prevent movement of said assembly longitudinally of 'the tubes. Y

2. A heat exchanger comprising a plurality Vof parallel .tubes arranged in at least two spaced-apart parallel rows, said `tubes having fins extending'outwardly therefrom and being secured to headers at opposite ends thereof, and a 'straightsubstantially inflexible bracing bar interposed in wedging relation between said rows of tubes inaedge -engagement with said tins, said bar comprising a strip of resilient material sandwiched between straight .elongate4 Y metal facing members, and a projection on at least one, said Vfacing member extending out of the planey thereof, said 'bar being wedged between said rows of tubes intermediate the ends of said tubes and extending transversely of the tubes so that said resilient material is compressed between said facing members thereby to inhibit vibration of said tubes, said projection engaging said tinsV in interlocking relation to prevent displacement of said bracing bar longitudinally of said tubes.

3. The combination recited in claim 2 Vin which one of said metal facing members is substantially U-shaped, said resilient means and another metal member being confined within theU-shaped member, and said projection being defined by a side of said U-shaped member extending beyond said confined metal member.

4. The combination recited in claim 2 in which at least one of said metal facing members is substantially T-shaped, and said projection is defined by the leg of said T-shaped member.

Y gated tubes arranged in a plurality of staggered parallel j .3.

5. The combination recited in claim 2 in which at least one of said metal facing members is substantially L- shaped, and said projection is defined by the leg of said L-shaped member.

6. The combination comprising a plurality of elongated inned tubes arranged in a plurality of parallel rows, the tins on tubes in adjacent rows being spaced apart a predetermined distance, and a plurality of substantially inflexible straight bars interposed in wedging relation between said rows of tubes for inhibiting vibration thereof, each said bar comprising a strip of resilient material` sandwiched between hard surfaced facing members and including a positioning projection on at least one said facing member extending out of the plane thereof, said bars each having a thickness greater than said predetermined distance and being wedged between said tubes transversely thereof so that said resilient material is compressed between said facing members by their wedging action against the tube fins, said positioning projections each interlocking with said tube tins to prevent displacement of said bars longitudinally of said tubes.

7. A heat exchanger comprising in combination, a plurality of parallel tubes arranged in a plurality of spacedapart parallel rows with the tubes of adjacent rows in staggered relation to form diagonal rows in angular relation with said parallel rows, said tubes having ns extending outwardly therefrom and being secured to headers at opposite ends thereof, outer side panels on said heat ex-A changer connected to said headers and disposed in parallel relation with said parallel rows of tubes, a plurality of straight, stiff bracing bars interposed between said diagonal rows of tubes in wedging relation, each said bar comprising a strip of resilient material having metal facing members on opposite sides thereof and a positioning projection on at least one such facing member extending out of plane thereof, said bracing bars being wedged between said diagonal rows of tubes transversely of the tubes so that said facing members engage said tins and said resilient material is compressed between said facing members, said positioning projections engaging a plurality of ins to prevent displacement of said bars longitudinally of the tubes, the ends of said bars extending transversely beyond said diagonal rows of tubes, and means including said side panels for engaging the extending ends of said bars to prevent displacement of said bars transversely of said tubes, said last-mentioned means including an adjustable abutment movable in a direction parallel to said side panels and engaging .the extending ends of at least some of said bars.

8. A heat exchanger comprising a plurality of elonrows, said tubes having tins extending outwardly therefrom, said tubes being secured to headers at opposite ends thereof, side panels on said heat exchanger removably connected to said headers, and straight elongated bracing assemblies for inhibiting vibration of said tubes, each assembly comprising a resilient laminate comprising resilient strips bonded to opposite faces of a metal carrier strip,

facilitate insertion between said tubes, said vibration in khibiting assemblies being wedged between said tubes transversely of the tubes so that said resilient laminate is compressed between said metal members by their wedging action against the tube iins, said projections engaging a plurality of ns to prevent movement of said assemblies longitudinally of the tubes, the ends of said assemblies extending transversely beyond said tubes, means prevent- Y ing movement of said assemblies transversely of said tubes by abutting their ends, the last mentioned means including said side panels contacting at least one end of some assemblies, `and a screw-actuated abutment adjustably movable longitudinally of said tubes contacting an end of some of said assemblies.

References Cited by the Examiner UNITED STATES PATENTS 1,592,538 7/ 26 Price 165-162 2,353,943 7/ 44 Storch 248-18 2,43 2,050 12/ 47 Thiry 248-35 8 2,927,78 l

CHARLES sUKALo, Primm Examiner.

HERBERT L, MARTIN, PERCY L. PATRICK,

Examiners.

3/60 Fohrhaltz et al 165-69

Claims (1)

1. THE COMBINATION COMPRISING A PLURALITY OF TUBES ARRANGED IN A PLURALITY OF ROWS, SAID TUBES HAVING FINS EXTENDING OUTWARDLY THEREFROM, MEANS SECURED TO THE ENDS OF SAID TUBES CLOSING OFF THE SPACE THEREBETWEEN, AND A STRAIGHT AND STIFF ELONGATE ASSEMBLY FOR INHIBITING VIBRATION OF SAID TUBES COMPRISING A STRIP OF RESILIENT MATERIAL, HARD SURFACED MEMBERS PROTECTING OPPOSITE FACES OF SAID RESILIENT MATERIAL FROM BEING CUT BY THE FINS, AND A PROJECTION ON A HARD SURFACED MEMBER EXTENDING OUT OF THE PLANE THEREOF, SAID VIBRATION INHIBITING ASSEMBLY BEING FIRMLY WEDGED BETWEEN SAID ROWS OF SAID TUBES INTERMEDIATE THEIR ENDS AND EXTENDING TRANSVERSELY OF THE TUBES AND IN ENGAGEMENT WITH EDGES OF SAID FINS, SAID RESILIENT MATERIAL BEING COMPRESSED BETWEEN SAID HARD SURFACED MEMBERS BY THEIR WEDGING ACTION AGAINST THE TUBE FINS, AND SAID PROJECTION INTERLOCKING WITH A PLURALITY OF SAID FINS TO PREVENT MOVEMENT OF SAID ASSEMBLY LONGITUDINALLY OF THE TUBES.

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