US2869834A - Heat exchanger - Google Patents

Description

Jan. 20, .1959

'J. A. CLARK, JR., ETAL 2,869,834

HEAT EXCHANGER Filed April 10, 1956 4 Sheets-Sheet 1 v i i MINI! N" m M [i Jan- 20, 1959 J. A. CLARK, JR., ETAL HEAT EXCHANGER 4 Sheets-Sheet 3 Filed April 10, 1956 NV. Q w 000000000 0000010 llufluflufl 0000000000 00000000 90w 0% 0000000000 00000000 0000000000 00000000 0000000000 00000000 0000000000 0 0000000 0000000000. 0.0000000 0000000000000000000000 0 000000000000000000000 0 0 0 6 0+ 0 9 0 0 0 ,nnnfinflun. W

Jan. 20, 1959 J. A. CLARK, JR, ETAL 2,869,834

HEAT EXCHANGER Filed April 10, 1956 4 Sheets-Sheet 4 United states Patent HEAT EXCHAN GER John A. Clark, Jr., Wheaton, Ill., and John J. Fischer,

East Stroudsburg, Pa., assignors to The Patterson- Ke'lley Co., Inc., East Stroudsburg, Pa.

Application April 10, 1956, Serial No. 577,245

2 Claims. (Cl. 257-235) This invention relates to heat exchange devices, and more particularly to high pressure dilferential heat exchanger constructions adapted specifically for cooling gases or liquids under extremely high pressures by means of relatively low pressure gases or liquids at opposite sides of the heat exchange surfaces.

The invention generally contemplates provision of a high pressure heat exchange device embodying the inherent advantages of a rectangular form of easing enclosing rectangularly bundled tubes, to obtain more nearly uniform gas fiow rates and efiicient heat exchange operation throughout the device; as distinguished, for example, from cylindrically shaped heat exchangers or the like. More specifically, the invention employs a generally rectangular outer casing interiorly of which are mounted pluralities of bundles of finned U-tubes about which low pressure gas circulates for heat exchange purposes, while passing through the interior of the rectangular casing. The U-tubes are mounted upon a tube sheet against which are attached a plurality of bonnets arranged to convey the inlet high pressure fluid first to the inlet ends of the first bank of tubes, and from the outlet ends thereof into the inlet ends of the next bank of tubes, and so on. It is a primary object of the present invention to provide an improved high pressure tube sheet and bonnet fabrication in a unit as aforesaid.

Another object of the invention is to provide a heat exchange mechanism as aforesaid which is of improved simplicity and ruggedness of construction, and economical to build, and easy to disassemble for cleaning or maintenance purposes.

Another object of the invention is to provide an improved heat exchanger as aforesaid which is of generally rectangular form and employs multiple banks of high pressure tube bundles mounted upon headers of improved design and construction.

Other objects and advantages of the invention will appear from the specification hereinafter.

' In the drawings:

Fig. l is a longitudinal vertical sectional view through a heat exchanger of the invention;

Fig. 2 is a bottom plan view thereof;

Fig. 3 is a bottom plan view of the tube sheet component of the assembly of Fig. 1, in disassembled rela- .tion; therefrom, I Fig. 4 is'a section taken along line lV-IV of Fig. 3; Fig, 5 is a top plan view ofthe bottom bonnet component of the high pressure chamber structure;

Fig. 6 is a section taken along line VI-VI of Fig. 5;

Fig. 7 is a fragmentary sectional view, on an enlarged scale, of a detail of Fig. 1;

Fig. 8 is a fragmentary elevational view taken along line VIII-VIII of Fig. 4.

Fig. 1 illustrates application of the invention to a heat exchange unit construction comprising a generally rectangular casing or housing 10 including a top wall 11, side walls 12, and end walls 14-14 formed of sheet metal welded together, and to a base plate hereinafter ill! 2369,8 34 Patented Jan. 20, 1959 ice 2 referred to as the tube sheet component, as indicated at 15. Pinned U-tubes as indicated at 20 are arranged in banks in longitudinally successively disposed positions, as indicated at 21, 22, 23, respectively. The tubes 20 are mounted upon the tube sheet 15 and connected to suitable inlet-out-let devices as will be explained more fully hereinafter, for conveyance of high pressure fluid therethrough; while the casing 10 which houses thetube bundles permits circulation of low pressure heat exchange gas or liquid about the exterior finned surfaces of the tubes, as from the casing inlet port 26 to the casing outlet port 28 as indicated in Fig. 1. Brackets as indicated at 29 may be arranged interiorly of the casing 10 to relatively support the tubes 20, while baffie plates 30-30 adjacent the inlet and outlet ports operate to guide the flow of gas through the casing 10 in such manner as to evenly distribute its fiow pattern throughout the interior of the casing. Also, support brackets 32 as shown adjacent the top portion of the casing 10 may be provided to embrace the upper ends of the tube bundles, thereby positionally stabilizing the latter in the casing and preventing by-pass of gases around the ends of the tube bundles.

The high pressure gas conveying chambers of the device are in the form of separate bonnets as indicated at 40, 41, 42, 43 (Figs. 1, 2, 5, 6, 7) of castings or weldments as shown in the drawing to comprise bottom plates 44 and wall plates 46 welded thereto as indicated at 47 (Figs. 6-7). Thus, as shown in Figs. 1, 2 and 6, the high pressure bonnet structures may be conveniently fabricated in the form of subassemblies comprising integral box-like structures of heavy plate material of such specifications as to withstand the pressures to be encountered.

It is a particular feature of the present invention that in event extremely high pressures are to be employed, the relatively vulnerable large area surfaces of the tube sheet and the bonnet plates 44 are relatively braced by means of stay bolts nested between the tube apertures through the tube sheet; the tube sheet 15 being predrilled and tapped as indicated at 58, to receive the stay bolts, and the bottom plates 44 of the bonnets being drilled as indicated at 59 to permit them to be slip-fitted upwardly upon the lower ends of the stay bolts. Aluminum gaskets as indicated at 60 between the tube sheet and the bonnets, and copper gaskets 61 under cap nuts 62 thereupon complete the assembly and relatively brace the bonnets and the tube sheet 15 to withstand the terrific pressure loads thereon.

The tube sheet 15 is of course suitably drilled as indicated at 64 to accommodate in slip-fitted relation therein the bottom ends of the heat exchange tubes 20; the tubes being preferably rolled into grooved portions of the tube sheet bores as indicated at 66, as is customary in boiler tube mounting practice.

As shown in the drawings in Figs. 1, 2, 5, 6, the high pressure gas inlet arrangement is provided inthe form of a pair of conduits designated -70 disposed along opposite sides of the left hand end portion, of the bonnet 40, and the conduits 76-70 connect into pres sure boxes 72-72 from which extend small diameter tubes 74 leading into the interior of the bonnet 40. The bonnet 40 is dimensioned longitudinally of the unit to embrace only the inlet ends of the first bank 21 of tubes 2%, and thus the incoming gases pass first upwardly through the left hand leg portions of the first bank of tubes and thence over and down into the left hand portion of the next adjacent pressure bonnet 41. Then, at the right hand end of the bonnet 41 the gases rise again through the left hand leg portions of the second bank 22 of tubes 20, whereupon they travel up and over and then down again into the left hand end portion of the next adjacent pressure aeeassa bonnet 42. Again, at the right hand end portion of compartment 22 the left hand leg portions of the tube bank 23 receive the gases and carry them up and over and thence down into the bonnet .3 from whence they exit through lateral tubes 79 into parallel discharge conduits 80-80.

It is a particular feature and advantage of the arrangement Of the present invention that the high pressure manifold construction is capable of withstanding extremely wide ranges of temperature change and pressure changes although the parts have been relatively assembled by means of relatively inexpensive and simple shop pro cedures. The U-tubes are of relatively small diameter in order to successfully withstand the pressure loads therein, and also in the interests of maximum heat transfer efliciency. The tube sheet areas between the tubes 28 are utilized to receive the stay bolts 55, and hence a practicable rectangular form tube and tube sheet arrangement is provided to withstand high pressures, wherein the pressure load is distributed and taken in relatively small increments by the tube sheet and bonnet structures.

The relatively fragile U-tubes are firmly and solidly supported within the unit by means of their connections to the tube-sheet and to the brackets 29 and to the supports 32; and are thus protected against damage during shifting or other movements of the device during transit, or the like. As shown in Figs. 1 and 2, the unit is readily supportable upon foot pedestals 84-84 at opposite sides thereof; but it will be appreciated that whereas only rne form of the invention has been shown and described in detail the invention is not so limited, but that various changes may be made therein without departing from the spirit of the invention or the scope of the appended 1 claims.

We claim:

1. A generally rectangularly shaped heat exchange device particularly adapted to withstand relatively high and low fluid pressures at opposite sides of the heat exchange partitions thereof, said device comprising a single rectangular shaped flat metal tube-sheet of high pressureresistant form, a plurality of box-shaped bonnets in opposed relation to said tube-sheet and aligned in the direction of the long axis thereof and including a first bonnet and a last bonnet, a system of tubes engaging said tube sheet, stay bolts extending between said tube sheet and said bonnets and engaging said tube sheet at positions intermediate of the positions of entry of said tubes through said tube sheet thereby maintaining said bonnets in'high pressure chambers-forming positions, the ends of said tubes at their positions of engagement With said tube sheet being arranged in a pattern of parallel groups of tubes, each of said groups of tubes being arranged closely about the position of one of said stay bolts, and each of said groups of tubes having at least two tubes arranged in close juxtaposition to one of said stay bolts, said system of tubes comprising a plurality of U-bent tubes mounted upon said tube sheet and having their interiors in open communication with said high pressure chambers and extending from the tube sheet in generally rectangularly bundled form, corresponding ends of the tubes of one of said bundles entering the high pressure chamber of one of said bonnets and the other ends of the tubes of said bundle entering said tube sheet at the high pressure chamber of the next adjacent bonnet, andso on, a single generally rectangular shaped low-pressure resistant casing enclosing all of said tube bundles and accommodating circulation of low pressure fluid through said casing and in heat exchange relation against said tubes, low pressure fluid inlet and outlet connections at opposite ends of said casing, and pluralities of high pressure fluid inlet and outlet connections arranged in rows at the sides of said first and last bonnet respectively.

2. A generally rectangularly shaped heat exchange device particularly. adapted to withstand relatively high and low fluid pressures at opposite sides of the heat exchange artitions thereof, said device comprising a single rectangular shaped flat metal tube-sheet of high pressureresistant form, a plurality of box-shaped bonnets in opposed relation to said tube-sheet and aligned in the direction of the long axis thereof and including a first bonnet and a last bonnet, a system of tubes engaging said tubesheet, stay bolts extending between said tube sheet and said bonnets and engaging said tube sheet at positions intermediate of the positions of entry of said tubes through said tube sheet thereby maintaining said bonnets in high pressure chambers-forming positions, the ends of said tubes at their position of engagement with said tube sheet being arranged in a pattern of parallel groups of tubes, each of said groups of tubes being arranged closely about the position of one of said stay bolts, and each of said groups of tubes having at least two tubes arranged in close juxtaposition to one of said stay bolts, said sys tem of tubes comprising a plurality of U-bent tubes mounted upon said tube sheet and having their interiors in open communication with said high pressure chambers and extending in cantilever fashion from the tube sheet in generally rectangularly bundled form, corresponding ends of the tubes of one of said bundles entering the high pressure chamber of one of said bonnets and the other ends of the tubes of said bundle entering said tube sheet at the high pressure chamber of the next adjacent bonnet, and so on, a single generally rectangular shaped low-pressure resistant casing enclosing all of said tube bundles and accommodating circulation of low pressure fluid through said casing and in heat exchange relation against said tubes, bracket means extending from said casing to bear against and positionally stabilize the bent portions of said tubes remote from said tube sheet, low pressure fluid inlet and outlet connections at opposite ends of said casing, pluralities of high pressure fluid inlet and outlet connections arranged in rows at the sides of said first and last bonnet respectively and extending laterally therefrom, and manifold conduits interconnecting respectively each set of high pressure inlet and outlet connections.

References (Jited in the file of this patent UNITED STATES PATENTS 433,190 Weir July 29, 1890 1,284,868 Braun Nov. 12, 1918 1,427,611 MacCamy Aug. 29, 1922 1,578,830 Jones et al. Mar. 30, 1926 1,894,692 Kerr et a1 Jan. 17, 1933 1,957,779 Hoppes May 8, 1934 1,964,256 Fahrenwald June 26, 1934 2,061,429 Leach Nov. 17, 1936 2,508,815 Dawes May 23, 1950 2,535,047 Dalinet al. Dec. 26, 1950 2,656,157 Wasielewski Oct. 20, 1953

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