Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F22—STEAM GENERATION
  • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
  • F22B37/00—Component parts or details of steam boilers
  • F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
  • F22B37/10—Water tubes; Accessories therefor
  • F22B37/20—Supporting arrangements, e.g. for securing water-tube sets
  • F22B37/202—Suspension and securing arrangements for contact heating surfaces

Definitions

• WASTE HEAT BOILERS This invention relates to waste heat boilers.
• a suitable waste heat boiler for such an application is constructed with a bank or a plurality of banks one above another in an upward gas flow path of parallel-connected return-flow tubes with horizontal limbs.
• the tubes extend between horizontal upper and lower headers serving as outlet and inlet headers or inlet and outlet headers.
• An effective way of maintaining the disposition of the tubes in a bank of the boiler in relation to one another and of supporting the tubes at two or more localities along the length of the tube bank is by the use of vertical plane apertured plates through which the horizontal tube limbs are threaded.
• apertured-plate spacing and supporting means for the tubes comprise at each of two or more localities along the lengths of the tube horizontal limbs a plurality of apertured plate strips in a row which extend vertically between common upper and common lower securing members and each of which apertured plate strips serves to support the horizontal limbs of a single tube only or at most of a few tubes only.
• Figure 1 is a sectional side elevation, schematically represented, of an upward gas flow path containing four tube banks of a waste heat boiler;
• Figure 2 is a scrap plan illustrating the sectionaliza tion of a superheating bank inlet header of the boiler
• Figure 3 is a representation on a larger scale of the upper elements of .certain hanger means of the boiler shown in Figure 1;
• Figure 4 is a sectional, front elevation, also schematically represented, of part of the boiler shown in Figure 1;
• Figure 5 shows in front view some of the hanger means elements of Figure 3;
• Figure 6 shows the welded-halves nature of apertured plate strips used in the two lower tube banks of the boiler
• Figure 7 illustrates the supporting by apertured plate strips of tubes comprising respectively single and double vertical rows of horizontal tube lints.
• Figure 9 shews the welded three-part nature of a modified apertured plate strip.
• a waste heat boiler for a gas turbine pcraer installation is constructed with four banks one above another in an upward flow path 1 of gas turbine exhaust gases, each bank comprising parallel-connected return-flow finned tubes with horizontal limbs.
• the gas flow path 1 is enclosed within a casing providing gas-tight heat insulating front, rear and side walls 2F, 2R and 2S respectively.
• the uppermost tube bank 3 of the four banks is a primary economizer tube bank arranged for generally downward flow therein of water supplied by a horizontal inlet header 4 positioned adjacent the front wall 2F and somewhat above the level of the tube bank 3.
• Ihe tube bank 5 next below the uppermost tube bank 3 is a secondary economizer tube bank arranged for generally downward flow of water therein, thence to a horizontal outlet header 6 positioned adjacent the front wall 2F and somewhat below the level of the tube bank 5.
• the tube bank 5 contains the same number of tubes as the tube bank 3 and the tubes of one bank are connected to the tubes of the other through respective connecting lengths 7 adjacent the front wall 2F.
• the tube bank 8 next below the tube bank 5 is a steamgenerating tube bank or so-called "boiler bank” arranged for generally downward flow therein of fluid which is supplied as water by a horizontal inlet header 9 positioned adjacent the rear wall 2R and somewhat above the level of the bank 8 and which as a water/steam mixture is withdrawn through a horizontal outlet header 10 positioned adjacent the rear wall 2R and somewhat below the level of the bank 8.
• the lowermost tube bank 11 is a steam superheating tube bank arranged for generally downward flow therein of .steam supplied by a horizontal inlet header 12 positioned adjacent the front wall 2F and somewhat above the level of the tube bank 11 and passing to a horizontal outlet header 13 positioned adjacent the front wall 2F and somewhat below the level of the tube bank 11.
• the econoimizer inlet header 4 has been referred to in the singular but it is secticnalized, comprising in fact two similar header lengths end to end, separate from one other but supplied with water in parallel.
• Ibe economizer outlet header 6 is simlarly sectionalized so that the primary economizer tube bank 3 consists of two bank sections side by side as does the secondary economizer tube bank 5.
• the boiler bank inlet and outlet headers 9 and 10 are similarly sectionalized so that the boiler bank 8 consists of two bank sections side by side.
• the superheater inlet header 12 is sectionalized, as is the stperheater outlet header 13, so that the superheating tube bank 11 consists of two bank sections side by side; these two bank sections are arranged to be traversed by steam not, however, in parallel but in series, one superheating bank section thus acting as a primary superiieater and the other superheating bank section thus acting as a secondary superheater.
• the boiler has a steam and water drun arranged at an elevated position 14 to the rear of the gas flow path 1 and a pump (not shown) for forced circulation of water froc the drum through the boiler bank 8 and as a steam and water mixture back to the drum.
• drum/forced circulation boilers are well-known, the water and steam pipes are omitted for the sake of simplicity: it is sufficient to state that appropriately situated piping:- leads incoming water to the two sections of the economizer inlet header 4; leads water to the drun from the two sections of the economizer outlet header 6; leads water from the drum to the mentioned pump; leads water from the pump to the two sections of the boiler bank inlet header 9; leads steam and water mixture to the drum from the two sections of the boiler bank outlet header 10; leads steam from the drum to the section 12P ( Figure 2) of the inlet header 12 which serves the primary superheating tube bank section; leads steam from the section of the outlet header 13 which serves the said primary superheating bank section to the section 12S-of the inlet header 12
• a spray-type attemperator (not sham) may be inserted in the steam piping between the outlet header section of the header 13 serving the primary superheater and the inlet header 12S section serving the secondary superh eater.
• the headers are attached to respective brackets which extend from the casing that provides the walls 2F, 2R and 2S, which casing is top-supported by structural steelwork of the boiler and expands, as the boiler heats up, downwardly in relation to the said structural steelwork, which remains at anfoient te ⁇ perature.
• the four tube banks are also top-supported from the said structural framework by means of hanger means 21M supporting the horizontal tube limbs of the bank tubes at the locality of their mid-points, hanger means 21F supporting the said tube lints at a locali ty adjacent their front ends and hanger means 21R supporting the said tube lints at a locality adjacent their rear ends.
• the said hanger means 21M include a horizontal bank support girder 22M conprising two H-section beams 23 which extend at right angles to the horizontal tube limbs of the banks and across the gas flow path 1 at a locality above the uppermost tube bank 3 and rest at their ends on structural steelwork of the boiler.
• the two beans 23 are spanned by respective horizontal support plates 24, each of which is apertured for the passage therethrough with play of a vertical bolt 25 carrying a nut 26 together with a washer 27 between the nut and the upper face of the plate 24, the washer having a spherically convex lower face 28 resting on the support plate.
• a clevis 29 the fork arms of which carry a horizontal pin 30 extending at right angles to the bank support girder 22.
• the several pins 30 pass th rough respective lugs 31 welded to the top flange surface of a common horizontal H-section beam 32, parallel to the girder 22M, which extends above and across the width of the bank 3.
• the tubes of the bank 3 are spaced from one another at their horizontal limb mid-points by a row extending across the width of the bank of vertically extending strips 33 of apertured plate which at their upper ends are individually removably attached to the lower flanges of the common H-section beam 32.
• the upper end of each apertured plate strip 33 carries welded thereto at right angles across it in the form of a T a rectangular attachment plate 34 through which by nuts and bolts 35 the plate strip is attached to the lower flanges of the H-section beam 32.
• Spacer collars 36 distance the attadimsnt plates 34 from the beam lower fl anges.
• apertured plate strips 33 cany welded-on similar attachment plates 34 through which by nuts and bolts 42 the strips are removably attached to the upper flanges of a cannon horizontal H-secticon beam 43, also parallel to the girder 22M, which extends below and across the width of the bank 3.
• the beam 43 is removably attached through its lower flanges to the upper flanges of a sirpilar H- section beam 32' therebelow.
• the beam 32 acts as the upper securing means for the row of apertured plate strips 33
• the beam 32' acts as the upper securing means for a row of apertured plate strips 33' spacing from one another at their mid-points the horizontal tube lints of the subjacent bank 5.
• a beam 43' below the bank 5 acts as the lower securing means for the row of apertured plate strips 33'.
• the hanger means 212F and 21R are similar to the hanger means 21M and it will be perceived that of the four tube banks each of the three lower banks is suspended from the tube bank above it with the aid of three rows of apertured plate strips respectively at the front, middle and rear of the tube bank while the uppermost tube bank is slung with the aid of three rows of apertured plate strips respectively at the front, middle and rear of the tube bank from respective upper bank support girders 22F, 22M and 22R resting cm the boiler structural steelwork, so that the whole colum of banks in the upward gas flow path is top-supported.
• Each apertured plate strip 33, 33', 33" and 33'" is of a kind sometimes known as a spectacle plate.
• each such plate strip serves for a single vertical row of horizontal tube lints of a bank; in order to fabricate and instal it, an integral strip of plate is firstly apertured at appropriate spaced locations along its length, it is then cut longitudinally tbrough the centres of the apertures into two halves, the two halves are offered to respective sides of the row of tube linbs and the two halves are welded together to form a single apertured plate strip pierced by the row of tube lints.
• the tubes bear no fins where they extend tbrougi the strip.
• attachment plates 34 are welded to the strip ends.
• each of the tubes is bent in a single vertical plane sinuousity, as indicated in Figure 7, and thus, in the bank, threaded through and supported by only three apertured plate strips, respectively at the front, at the mid-point and at the rear of the tube horizontal lints.
• a tube of either bank, let us say, of the boiler bank 8 fails in boiler operation, it may after the boiler has cooled, be rendered capable of withdrawal by severing its connections at regions 45 and 46 with the respective upper and lower headers 9 and 10, and removing nuts and bolts to detach the three apertured plate strips 33" both from the three respective upper strip securing beams 32" and from the three respective lower strip securing beams 43".
• the tube-with its three apertured plate strips is then freely movable within the lateral limits of the adjoining tubes and with the removal of the spacer collars 36 is also freely movable within vertical limits and may be quickly and readily removed through an aperture (not shown) of normal kind in the casing of the gas flow path, without disturbing the remaining tubes of the bank or any of the other banks.
• a replacement consisting of a similar but sound tube threaded on three similar plate strips can then be quickly and readily inserted into the tube bank 8 and the nuts, bolts and spacer collars quickly secured. After the welding of the new tube at regions 45 and 46 to connect it with the headers 9 and 10 the boiler is again ready for service.
• each of the tubes in each of the upper tube banks 3 and 5 each of the tubes is bent sinuously so that its horizontal tube limbs are arranged in two vertical planes, as indicated in Figure 8, and in each of the three rows of apertured plate strips two side by side of the strips 33 or 33' are pierced by the tube and used to sipport the tube and space the horizontal lints from one another and form the horizontal lints of adjoining tubes.
• any such tube may be effected in the'same manner as already described except that six apertured plate strips must be detached with the failed tube and re-attacaed with, the sound tube and except also that one of the ttibe connections to be severed and re-made is that to a header whereas the other is in a connecting length 7.
• All the upper and lower strip-securing beans for the tube banks and the bank support girders 22F, 22M, 22R extend across the upward gas flow path and expand as the boiler heats up.
• the three bank support girders rest at their ends through low friction bearings on structural steel work of the boiler.
• the tubes which do not fit tightly in the plate strip apertures, also ejpand and in order to reduce the amounts of movements of the tubes in relation to the plate strips supporting the tubes at the ends of their horizontal lints the front and rear bank support girders 22F and 22R are connected to the midway bank support girder 22M by tie rods (not shown) which, on expanding under heat, will increase the distances between the bank support girders as the tube horizontal lints expand.
• the reference numerals 47 designate baffle plates extending from the walls 2F and 2R and provided to inhibit upward gas flow otherwise than over the horizontal lints of the tubes of the banks.
• the described boiler uses apertured plate strips which are pierced by single vertical rows only of tube straight lints.
• an apertured plate strip might serve for more than two such rows; if it is to serve for, say, two rows, it will be apertured in two longitudinal rows (see Figure 9) and cut along the rows of apertures into three parts wbich, after being offered to the .tubes, are subsequently joined by welding 44 in a single apertured plate strip, to which attachment plates will be welded at its two ends.
• the two vertical rows of tube lints might pertain to one tube only or to two or at most a few tubes.
• each bank with the apertured plate strips attached to the upper and lower strip- securing beams for the bank might be assembled in the manufacturing workshop and transported and incorporated in the boiler on site as a unit; if the tube bank is inconveniently wide, however, the bank might be transported in sections, provided the headers are appropriately sectionali zed, without the upper and lower strip-securing beams therefor, the apertured plate strips for each bank section being then attached for transportation purposes to beans of an appropriate shipping frame.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

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ID=10523252

Family Applications (1)

Country Status (6)

Cited By (3)

Citations (10)

• 1982
  • 1982-07-15 AU AU86840/82A patent/AU544847B2/en not_active Ceased
  • 1982-07-15 GB GB08320432A patent/GB2123127B/en not_active Expired
  • 1982-07-15 NL NLAANVRAGE8220234,A patent/NL182169C/xx not_active IP Right Cessation
  • 1982-07-15 WO PCT/GB1982/000211 patent/WO1983000371A1/en not_active Ceased
  • 1982-07-19 IN IN547/DEL/82A patent/IN158351B/en unknown
• 1983
  • 1983-08-12 FI FI832912A patent/FI71828C/fi not_active IP Right Cessation

Patent Citations (10)

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