US2134713A - Fluid heat exchange apparatus - Google Patents

Description

Nov. 1, 1938. F. x. GlLG 2,134,713

FLUID HEAT EXCHANGE APPARATUS Filed Feb. 19, 1935 3 SheetsSheet 1 Fig 1 INVENTORS .F'ra 17 k )x (if/ ATTORNEY Nov. 1, 1938. F. x. GILG FLUID HEAT EXCHANGE APPARATUS 3 Sheets-Sheet 2 A ITORNEY Nov. 1, 1938. F. x. GILG FLUID HEAT EXCHANGE APPARATUS Filed Feb. 19, 1935 A TO 3 Sheets-Sheet 5 RNEY Patented Nov. 1, 1938 UNITED STATES PATENT QFFECE FLUID HEAT EXCHANGE APPARATUS Application February 19, 1935, Serial No. 1,164

11 Claims.

This invention relates to fluid heat exchange apparatus exemplified herein by a superheater associated with a steam boiler.

The invention involves improvements in heat 5 absorbing parts of a high pressure and high temperature steam generating unit, the normal operation of which subjects those parts to a considerable range of variation of high temperatures. It is an object of the invention to so relate the tubular elements of such heat absorbers and their associated elements 'as an entire assembly, when properly located in a boiler installation, that excessive expansion strains and stresses due to wide temperature variations will not interfere with the maintenance of the absorbers in proper operative condition and position. The invention will be clearly understood from the following description of the installation indicated in the accompanying drawings, in which:

Fig. 1 is a view in the nature of a vertical section, showing an interdeck superheater in a steam boiler, of the B. 8: W. type.

Fig. 2 is an enlarged view in the nature of a vertical section showing the superheater of the Fig. 1 installation.

Fig. 3 is a transverse section taken on the line 33 of Fig. 2.

Fig. 4 is a detailed section on the line 4-4 of Fig. 3.

Fig. 5 is an enlarged sectional view showing some details of the baflie and tube supports of the Fig. l boiler unit.

Fig. 6 is a vertical section taken on the line 6-6 of Fig. 5 and showing the structure for supof steam generating tubes of the boiler, this lower row providing support for the superheater.

Figs. 7 and 8 are detailed views of slip hangers for suspending superheater tubes from other superheater tubes.

Fig. 9 is an enlarged view showing the manner in which the superheater is maintained so as to permit relative movements between it and the steam generating tubes.

Fig. 10 is a partial plan view of the parts shown in Fig. 9.

Fig. l of the drawings indicates an interdeck superheater positioned between a single pass lower bank of steam generating tubes I0 and an upper bank of the steam generating tubes l2. The superheater is located in a gas pass at a position where the gas pass is of a width less than that of the lower bank. The upper bank of steam generating tubes is indicated as being located in two gas passes with a baffle between them.

porting the lower row of tubes of the upper bank,

The superheater receives its steam from an inlet header M which is connected with the steam space of the drum by the row of saturated steam supply tubes It. The steam is conducted from the header l4 through the superheater inlet tubes 5 20 and 22 which are arranged in horizontal and vertical rows, there being vertical rows with two tubes in each row at positions where the inlet tubes pass between the nipples 24. These nipples connect the headers of the upper and lower bank 10 of steam generating tubes. Inwardly of the nipples 24, the tubes 20 and 22 form a single inclined row as indicated at 26 in Fig. 1. This single row constitutes part of a gas baflie separating high temperature superheating gases from gases of lower temperature leaving the boiler. This row of tubes also constitutes a wall tube section of the entire superheater. The tubes of the row extend upwardly to positions adjacent the lowermost rows of steam generating tubes of the upper bank. At these positions they are also adjacent the lower end of the baffle 58 separating the two gas passes of the upper bank. From this position the tubes extend as rows of superheater'tubes recurrently back and forth across the gas passes, forming a number of superheater loops which are swept transversely by the upfiowing hot gases. The upper row of loops may be considered as constituting a low temperature section of the superheater and the lower row of loops as con- 30 stituting the highest temperature section, the temperature of the steam flowing through the superheater and the temperature of the metal of the superheater parts rising progressively from the top to the bottom of the entire bank of tubes formed by the superheater loops.

superheated steam passes to the outlet header 3*! from the outlet ends 36 of the continuous superheater tubes, these outlet ends being arranged in two horizontal rows with the tubes 4 of the upper rows directly superposed with respect to corresponding tubes of the lower rows where the tubes pass between the nipples 38 which connect the uptake headers 32 and 40 of the steam generating tubes. The-steam then passes from the outlet header 34 to a point of use.

The superheater illustrated in drawings may be considered as having two sections, one of which is a wall section forming a boundary of a gas pass in which the other section is located as a 5 bank of looped rows of tubes arranged for an upflow of hot gases transversely and cross the bank in a gas pass of less width than the gas pass below the bank of superheater tubes.

The superheateras an entirety maybe con- '5 which are preferably welded to sidered as being top supported at the ends of its section formed by the bank of looped tubes. At one end, brackets 42 are welded to the nipples 38. Complementary brackets 44 are shown welded to the uppermost superheater loops 46. Rollers 48 are arranged between these brackets to allow some relative motion of the associated parts. At the end of the bank section of the superheater where it meets the wall section including the inlet tubes 26, similar means are provided 4 for maintaining the bank section f the superheater in position. As shown, these means include the metallic supports or hooks 50 preferably welded to the top parts of the inclined tubes oi. the wall section 26. They cooperate with rollers 52 carried in the upwardly opening hooks 54 the lowermost tubes of the upper steam generating bank. The gravitational load imposed by the weight of the superheater upon the bottom row of tubes of the upper bank may be distributed throughout the tubes of that bank by a baflle 58 having bars 60 extending upwardly between the rows of tubes of the upper bank. 6 v

In the embodiment of the invention indicated in Figs. 1, and 6, the lowermost row of tubes of the upper steam generating bank is supported intermediate its ends by beams 62 which are preferably carried by members connected to the structural framework above the boiler and located in a zone of relative cool gases. In the arrangement of elements shown particularly in Fig. 6 of the drawings, upper horizontals 64 are connected by oblique tension rods 66 and 68 to the lower horizontal members 62. Above the upper bank of steam generating tubes the horizontals 64 are connected to the vertical tension rods 70 extending downwardly from and secured to external framework.

As shown in Fig. 2 the top row 01' superheater loops 12 at the end 01' the superheater bank section, near the wall section of the superheater are rigidly connected with the tubes 26 of the latter section by metallic webs 14. These webs are preferably welded at both ends to the tubes of the superheater. Similarly secured webs, 16-19 in elusive, are arranged in a vertical row midway oi the length of the bank section of the superheater. Several successively lower rows of tubes of the bank section of the superheater, beginning at the top, are thus rigidly connected to approximately midway of the ends of the bank section.

In addition to being rigidly connected at the middle of the bank section by the 'webs 16-19 the successively lower tubes of the bank section of the superheater are also rigidly connected by two groups of webs, 86-88 inclusive, preferably arranged in downwardly converging rows as shown. These rows converge downwardly from positions near the opposite ends of the bank section of the superheater near its end supports toward a position below the central web 19. The relatively small temperature difl'erences between the tubes thus connected imposes no more expansion than can be met by a slight bending of the tubes between the rigid connections aflorded by the webs between successive rows. Rows of tubes below these rigidly connected sections are more highly heated. They are, therefore, not rigidly connected, but have supporting connections preventin relative movements between them.

The successively lower rows of tubes 89-93 inclusive of the bank section of the superheater are supported, each from the one above it,.by slip hangers 94-98 arranged as shown in a. vertical same time, heat is radiated to line in the middle of the bank. There is another row of similar slip hangers I 04-!01 at the righthand end of the bank, and another row of slip hangers llll-l l3 at the opposite end of the bank. These slip hangers may be constructed in accordance with the disclosures of Figs. 7 and 8 to permit the adjacent rows of superheater tubes to have relative movement in response to the different temperature variations to which they are subjected. The lower tube A of each section may have a downwardly bowed loop I00 welded thereto at its end. The upper tube B has a downwardly bowed loop llll extending through the loop I06 and welded at their ends to the tube. Not only is relative movement between adjacent tubes permitted by reason of the fact that the metal of the loop llll has a Width much less than the width of the loop I00, but relative motion in a transverse direction is permitted by reason of the fact that the loop IOI is considerably wider than the metal of the loop I00. The successive rows oi! tubes of the lower part of the superheater bank section are thus free to expand or contract longitudinally and horizontally while being adequately supported vertically.

In the event that the conditions in the tubes of the upper rows of the nectors shown in Fig. 2 impose excessively severe stresses due to expansion, the slip hanger connectors shown in the lower rows of the bank may also be usedfor the upper rows, wholly or in part, as shown in Fig. 1.

The wall section of the superheater having the tubes 26 is shown in detail in Figs. 3 and 4. In addition to the tubes 26, it consists of tile sections H4 closing the spaces between the adjacent tubes. These tile sections are backed by metal plate panels H6, adjacent panels being joined by connectors H8 extending through the upright flanges of the panels on opposite sides of the plate I24 which may bewelded to the tubes 26 and slotted to prevent distortion by expansion. These connectors also extend through the links I20 which are connected to adjustable tension members I22. These tension members prevent excessive bending of the tubes 26 as they expand downwardly from they are fixedly supported by the hooks 50. The tension members I22 are shown as connected to the tubes 26 at a position midway of the wall section of the superheater.

In operation, the gases rising from the lower bank 01' steam generating tubes approach the superheater at the high temperatures required for the attainment of a high degree of superheat, in a superheater 01' minimum practicable heating surface. The invention as here described provides a combination that not only insures such a result but also provides a superheater which is structurally safe to operate: It is reliable by reason of the structural features herein disclosed. Part of the heat from the gases is abstracted by the wall section of the superheater which deflects the gas stream and contracts the gas pass. The gases sweep the tubes of the wall section while, simultaneously, the body of hot gases radiates heat directly to the tubes of the wall the positions at which section. The contracted stream of hot gases in which the bank section is located sweeps the tubes of that section andheat is transferred to them to superheat the steam at a rate depending on .the gas velocity, and the area of the gas pass which can be given any suitable value by the selection of the angle of the wall section. At the the tubes of the working temperature bank section from the gas body below and above Figs. 1 and 2 of the drawings indicate an arrangement of elements for supporting the superheater outlet header 34. This arrangement includes curved beams I30 secured to the nipples 38 of the steam generating part of the boiler by the clamps I32. These beams are attached at their other ends to tension members I34, preferably supported from brackets I36 secured to the steam generating uptake header 32. Where desirable, the superheated steam outlet header may be arranged to slide horizontally on these beam supports.

Fig. 1 of the drawings shows the steam generating uptake header'32 to be connected to the steam space of the drum I6 by lower circulators I40 and I42 leading from the sides of the headers 32. Similar connections are also afforded by upper circulators I44 and I46 leading from the upper ends of the headers 32. The several circulators in one vertical row preferably enter the drum at diiferent levels. Their tube seats may be arranged in one circumferential row. The headers of the steam generating part of the boiler are preferably pendently supported by rods I48 which are secured to any suitable exterior framework. Downtake nipples I50 connect the steam generating header 3D with the water space of the drum I6. The latter is supported from above by U straps I52.

Beneath the boiler there is arranged a furnace which may have its walls fluid cooled by water tubes I54 and I56 connected at their upper ends respectively to headers I58 and I60. The header I58 is connected by a riser I62 to the steaim space of the drum I6 and the headers I60 may be similarly connected to the water space of the drum. The latter connections are preferably at a level different from that of the other circulators.

While the invention has been described with reference to the particular embodiments illustrated in the drawings it is not limited thereto, but is of a scope commensurate with the subjoined claims.

What is claimed is:

1. In a water tube steam boiler, a bank of tubes of a superheater having series connected multiple loops, means constituting top supports for the superheater at its ends, metallic intertube connectors rigid with successive tubes of the low temperature section of said bank and forming with said tubes a structure in the nature of a truss, and slip hangers supporting the remaining tubes of said bank from said truss.

2. In a superheater of the multiple loop type,

metallic inter-tube connectors rigid with the lower temperature loops and arranged therewith to constitute a short span deck truss, means for supporting said truss at the upper part of the superheater, and slip hangers connecting the remaining superheater loops and supporting them from said truss.

3. In a water tube steam boiler, a bank of tubes of. a superheater constituting series connected multiple loops, means including rollers constituting top supports for said bank of tubes at its ends, metallic inter-tube connectors welded to successive tubes of the low temperature section of said bank and forming with said tubes a structure in the nature of a short span deck truss, and slip hangers supporting the remaining tubes of said bank from said truss.

4. In a superheater of the multiple loop type, metallic inter-tube connectors welded to the tubes of. the lower temperature loops and arranged therewith to constitute a short span deck truss, end supports for said truss at the upper part of the superheater, and inter-tube slip hangers connecting the tubes of the remaining superheater loops and supporting them from said truss, some of said slip hangers being arranged in an upright row beneath an intermediate portion of said truss.

5. In a counter-flow superheater of the multiple loop type, tube-to-tube connectors rigid with successive tubes of the lower temperature loops and arranged therewith to constitute a short span deck truss, supports for said truss and sliding inter-tube supports between the higher temperature loops of the superheater.

6. In an interdeck superheater, a row of inclined superheater inlet tubes acting as wall tubes constituting a part of. a bafile in the interdeck position, a plurality of superposed and series connected superheater loops disposed in the gas pass in front of the inlet tubes, an outlet header communicating with said loops, means for rigidly tying the low temperature loops together to form a structure in the nature of a short span deck truss, supports for said truss and slip hangers supporting the higher temperature loops from said truss.

7. In a steam boiler, an upper bank of steam generating tubes, 9. lower bank of steam generating tubes spaced vertically from the first bank, uptake and downtake header constructions at the ends ofv said banks, a drum, means for connecting the headers and the drum, a furnace, a row of inclined superheater tubes acting as wall tubes forming part of a baifle in the space between said banks and extending from the lower end of the second bank toward the first bank at a position intermediate its ends, a bank of superheater tubes connected to the inlet tubes and arranged in multiple loop formation between the upper portions of the inlet tubes and the uptake headers, means for supporting the upper portions of the inlet tubes from the upper bank, means connecting the superheater bank to said upper portions, means for supporting the end of the superheater bank opposite the inlet tubes, metallic inter-tube connectors rigid with the superheater tubes of lower temperature and arranged therewith to form a truss, and slip-hangers supporting the remaining superheater tubes from said truss.

8. In a steam boiler, an upper bank of steam generating tubes, a lower bank of steam generating tubes spaced vertically from the first bank, uptake and downtake header constructions at the ends of said banks, a drum, means for connecting the headers and the drum, a furnace, a row of inclined superheater tubes acting as wall tubes forming part of a baffle in the space between said banks and extending from the downtake end of the second bank toward the first bank at a position intermediate its ends, a bank of superheater tubes connected to the inlet tubes and arranged in multiple loop formation between the upper portions of the inlet tubes and the uptake headers, means including lugs welded to the lowermost tubes of the upper bank for supporting the upper portions of the inlet tubes through the upper bank, means connecting the superheater bank to said upper portions, means for movably supporting the end of. the superheater bank opposite from the inlet tubes, metallic intertube connectors welded to the superheater tubes of lower temperature and arranged therewith to form a truss, and slip-hangers connecting the remaining superheater tubes to said truss.

9. The combination in a superheater, of a pair of headers and units connected therebetween, said units each comprising a plurality of vertically spaced horizontally extending pipe runs serially connected by return bends, stiffening means fixed between the upper pipe runs to form a girder thereof, means for freely suspending the pipe runs below the girder forming pipe runs from the girder, and means for supporting the girder, said last named means including an end portion of the superheater unit.

10. In a fluid heater, spaced tubes subjecting a contained fluid to heat transfer with reference to an external fluid through which the tubes extend, adjacent tubes being subjected to different temperature differentials causing unequal expansion and contraction eflects, means joining adjacent tubes in one temperature difierential zone to form a structure in the nature of a girder, motion permitting inter-tube devices supporting the remaining tubes from the girder and in a. zone of another temperature differential, said devices permitting the latter tubes individually to have different expansion and contraction movements, and means supporting'the girder.

11. In fluid heat exchange apparatus, upper and lower groups of spaced tubes extending across a fluid passage, means for connecting the tubes in series, rigid metallic spacers between successive tubes of the upper group and co-acting therewith to form a supporting structure, means for supporting said structure, and slip joint hangers disposed along the lower tubes so as to suspend the tubes of the lower group from said structure, the tubes of the lower group being in a zone of hotter gases.

FRANK X. GILG.

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