US3212481A - Integral box construction for steam generators - Google Patents

Description

Oct. 19, 1965 s. F. MUMFORD ETAL 3,212,481

INTEGRAL BOX CONSTRUCTION FOR STEAM GENERATORS Filed July 21, 1964 4 Sheets-Sheet 1 STEPHEN F. MUMFORD 36 34 RAMSEY U. SHEIKH FIG. 4

Oct. 19, 1965 s. F. MUMFORD ETAL 3,212,481

INTEGRAL BOX CONSTRUCTION FDR STEAM GENERATORS Filed July 21, 1964 4 Sheets-Sheet 2 nnuvwnc 36 54 22x 28A 12Xj d STEPHEN F. MUMFORD RAMSEY U. SHEIKH g ramz MW awe/Mm:

Oct. 19, 1965 s. F. MUMFORD ETAL 3,

INTEGRAL BOX CONSTRUCTION FOR STEAM GENERATORS Filed July 21, 1964 4 Sheets-Sheet 3 STEPHEN E MUMFORD RAMSEY U. SHEIKH 1965 s. F. MUMFORD ETAL 3,212,481

INTEGRAL BOX CONSTRUCTION FOR STEAM GENERATORS 4 Sheets-Sheet 4 Filed July 21, 1964 FIG. 9

INVENTORS. STEPHEN F. MUMFORD RAMSEY U. SHEIKH ATTORNEY United States Patent 3,212,481 INTEGRAL BGX CONSTRUCTION FOR STEAM GENERATORS Stephen F. Mumford, Bloomfield, Conn., and Ramsey U. Sheikh, Westhoro, Mass, assignors to Combustion Engineering, Inc., Windsor, Conn., a corporation of Delaware Filed July 21, 1964, Ser. No. 384,111 Claims. (Cl. 122510) This application is a continuation-in-part of US. patent application Serial No. 155,546, filed November 29, 1961, now abandoned.

This invention relates to vapor generators. More particularly, the invention relates to an improved steam generating apparatus of integral, welded wall construction designed to accommodate steam loads in the range of 80,000 to 600,000 lbs. of steam per hour with steam temperatures in the range of about 1000 F. and design pressures of about 1600 psi.

In the construction of high capacity steam generators considerable expense is realized in the time and effort expended in field erection of individual generator elements as well as in the cost of the materials employed in the construction of the generator. It is, therefore, an object of the invention to provide a novel compact steam generating apparatus utilizing standardized, shop-assembled components to the maximum extent possible so as to substantially reduce the time and effort normally required for field erecting such units and to reduce the material costs of such structures.

Another object is to provide a high capacity steam generator that is bottom supported in such a manner as to require a minimum amount of supporting members. This is attained by providing a compact unit having walls in the form of integral tubular panels so arranged as to effect vertical thermal expansion and thereby eliminate the need for external, heavy steel supporting members. The utilization of welded wall construction throughout the unit in addition to the particular arrangement of the various elements so as to reduce the unsupported length of the walls obtains a rigid, box-like structure that renders the unit substantially self supporting.

A further object is to provide a high capacity steam generator that is selfencasing to the extent that the need for heavy skin casing or other pressure sealing material is substantially eliminated. This is attained by the utilization of welded tube construction throughout all the enclosing walls, roof and floor of the steam generator thereby permitting the tubular elements to serve as the pressure containment structure.

Various other objects and advantages will appear from the following description of one embodiment of the invention, and the novel features will be particularly pointed out hereinafter in connection with the appended claims.

The invention is described with reference to the accompanying drawings wherein:

FIG. 1 is a sectional elevation of a steam generator constructed in accordance with the instant invention;

FIGS. 2 and 3 are diagrammatic perspectives of the steam generator shown in FIG. 1;

FIG. 4 is a typical section through one of the walls of the steam generator;

FIG. 5 is a transverse section taken along line 55 in FIG. 1;

FIG. 6 is a partial plan view of the lower drum and supply tubes of the steam generator;

FIG. 7 is a partial plan view of the upper drum and riser tubes of the steam generator;

FIG. 8 is a plan view illustrating the arrangement of the floor supports for the steam generator;

FIG. 9 is a partial elevation illustrating the lower drum and its supports;

FIG. 10 is a side elevation of the boiler bank section of the steam generator; and

FIG. 11 is an enlarged partial view of the wall structure of FIG. 5.

Referring now to the drawings there is shown a compact, bottom supported steam generator unit 10 having enclosing front, rear and opposed side walls, 12, 14 and 16 respectively, defining a furnace portion 18 and a boiler bank portion 20 separated by a gas impervious barrier or baffle 22. The boiler bank portion 20 includes lower and upper drums, 24 and 26, that are parallelly disposed and that extend between the side walls 16 of the unit and a bank of heat exchanger tubes 28 interconnecting the drums in fluid circulation. The boiler bank tubes 28 are arranged such that the rear row 28A forms the generator rear wall 14 and the outer end rows 28B are aligned with the furnace side walls 16 thereby forming a welded enclosure generally having the shape of a rectangular prism. The furnace 18 and boiler bank 20 are mutually connected for gas circulation by a gas pass 30 formed between the upper end of the gas bafiie 22 and the roof 38 within which is positioned tubes forming a superheater 32.

In accordance with the invention, as shown in FIG. 5, the entire periphery of the unit is formed of continuous, Welded wall construction. By this is meant that the enclosing walls or perimetric surfaces of the unit are all constructed of tubular barriers, typical sections of which are shown in FIGS. 4, 5, 6, comprising spaced tubes 34 having metallic strips or bars 36 fitted and welded therebetween to form a continuous gas impervious enclosure. The tubes 34, which have a 3 inch CD. are typically spaced spacedly arranged in side-by-side relation on 4 inch centers with a metallic filler or bar 36 interposed between and welded to adjacent tubes. The filler material is required to be of sufiicient thickness to withstand the gas pressure within the unit. A metal bar having a thickness of approximately inch is deemed sufiicient for this purpose in the disclosed embodiment. As an alternative, the Welded wall construction can comprise a plurality of aligned tubes having longitudinally extending diametral fins that are arranged in abutting side-by-side relation and joined by a continuous longitudinal weld.

With reference to FIG. 1, the furnace 18 is enclosed on three sides by front wall 12, roof 38 and floor 40. The roof 38 and floor 40 are formed by the leg segments of parallel C-shaped tubes that extend laterally from the upper drum 26 and lower drum 24 respectively, the vertically elongated bight of which tubes form the front wall 12. Spaces 39 are provided between adjacent tubes in the roof 38 to accommodate the passage of superheater inlet and outlet connector lines 42 and 44. The furnace enclosure is completed by side walls 16 that comprise a plurality of vertically extending tubes joined at their ends for parallel flow by upper headers 46 and lower headers 48. Supply tubes 50 (FIG. 6) connect the lower headers 48 to lower drum 24 and relief tubes 52 (FIG. 7) that are similarly connected join the upper headers 46 to the upper drum 26.

Thermal insulation 54 in the form of mineral wool or the like is applied to the outer surface of the generator walls being attached thereto as shown in FIG. 4 by means of impaling pins 56 or any other convenient means. Preformed lagging 58 comprising a thin metallic material such as steel or aluminum covers the insulation in order to enhance the appearance of the unit and also to protect the insulation against the effect of environmental elements.

Burners 60 are mounted by appropriate burner mounts in the lower portion of the front wall 16 for generating combustion gases within the furnace 18. These gases are caused to flow from the furnace 18 over the superheater tubes in gas pass 30 into the boiler bank portion 20 where refractory bafiies 62 suitably attached to the tubes 28 direct the gases laterally across the tubes before they exit through an opening 64 located at the bottom of the boiler bank.

As shown, a regenerative air heater 66 having a gas inlet 68 communicating with the opening 64 is located at the rear of the unit. The air outlet 70 of the air heater 66 communicates with an air plenum chamber 72 formed beneath the furnace floor 40 the latter supplying air to a burner windbox 74 that surrounds the burners 60.

The gas baffle 22 that separates the furnace 18 from the boiler bank 20 comprises a row of parallel tubes 22A (FIG. positioned forward of the front row of boiler bank tubes 28. These tubes 22A are of welded wall construction throughout the portion of their length indicated by the filler strip 36. They extend the full height of the unit connecting at their lower ends to lower drum 24 and at their upper ends to upper drum 26. As shown, the gas baffle tubes 22A emanate laterally from the lower drum 24, extending vertically through the lower portion of the furnace 18 and then are laterally offset below, but closely adjacent, the lower ends of the superheater tubes 32 thus forming a baffie nose 76 which is effective to protect the superheater tubes against exposure to the radiant heat in the furnace. The tubes 22A thereafter extend to the rear of the superheater 32 and are then vertically offset to extend across the gas pass 30 and connect with the upper drum 26. The welded construction of the bafiie 22 extends from the lower drum 26 to a point immediately below the rear of the superheater 32. Through this portion of their length adjacent tubes 22A are connected by metallic bars 36 or may be of the welded fin type alluded to hereinabove. Across the gas pass 30 the tubes are spaced with alternate tubes, indicated as 22B, being rearwardly and laterally offset so as to provide adequate space through which the gases generated in the furnace 18 can flow to the boiler bank 20.

As best shown in FIGS. 5 and 6 the gas bafile 22 extends across the full width of the generator unit between opposed side walls 16 with the endmost fins or bars 36 in the baffle 22 weldedly attached to each of the side walls 16. In this manner gases generated by burners 60 are prevented from flowing directly into the boiler bank 20 but instead are directed upwardly by means of the sloping leg 78 that forms a portion of the nose bafi le 76 toward the upper front corner of the furnace 18 where a turn is made by the gases and thence they flow through gas pass 30 and into boiler bank 20.

By weldedly attaching the gas bafile 22 to the side Walls 16 the unsupported length of the side walls is considerably reduced thereby serving to render the generator more rigid in its construction. This strengthening of the unit thus permits the elimination of expensive external structural steel supporting members and enables the generator to be completely bottom supported requiring the minimum amount of footing supports. The bottom support arrangement employed in the disclosed unit is described with reference to FIGS. 1, and 11. The arrangement comprises reinforced concrete pedestals 80 and 82 that are positioned beneath the generator adjacent the four corners thereof. Pedestals 80 are positioned at the rear of the unit and are of a size to permit mounting of lower drum cradle supports 84 and rear support footings 86 while the forward pedestals 82 are somewhat smaller in that they need only mount the forward support footings 88. While the rear support footings 86 are not, in fact, necessary in the support of the assembled generator since the weight of the unit in this area is adequately supported by the cradle supports 84, they are found to be useful in the erection of the unit serving to support the side walls 16 during the erection period and for this reason are included in the arrangement. The lower drum cradle supports 84 comprise drum cradles 90 mounted on rear pedestals 80. The drum cradles are positioned adjacent the ends of the lower drum 24 which rests therein being rigidly attached thereto by means of welding. The drum cradles 90 are each mounte-d upon a base plate 94 which is slidably positioned atop a pedestal plate 96 that is fixedly attached to the pedestal 80. Lateral stop members 98 are fastened to the plates 96 so as to limit the lateral movement of the cradle supports 84 during expansion of the generator. In this manner the point of zero expansion in the generator is substantially fixed at the point indicated as O which is substantially the axial midpoint of the drum 24. The stops 98 are sufficiently spaced from the edges of the pedestal plate 96 to adequately accommodate lateral expansion of the unit in one direction. Their purpose, however, is to limit the expansion of one end of the drum should the other end be prevented from expanding as by its associated cradle base plate 94 being bound upon the associated pedestal plate 96 and therefore unable to move. Should this occur the expandable end of the drum will move until the associated cradle base plate 94 engages the stop member 98 at which time the expansion force created will be in the other direction and sufficient to overcome the friction between the base plate 94 and pedestal plate 96 associated with the other end of the drum so as to establish movement at that end and thereby maintain the point of zero expansion at the point 0.

Each support footing 86 and 88 comprises a short, cylindrical, vertical column 100 which is rigidly attached as by means of welding to the underside of the lower headers 48. The column 100 is fixedly mounted upon a footing base 102 which in turn is slidably mounted atop the pedestals 62 and 64 upon plates 104. As shown in FIG. 11 each of the footings 86 and 88 is radially oriented with respect to the point 0, such orientation being effected by means of brackets 106 provided on each of the footing plates 104 to engage the edges of the associated footing base 102 and thereby limit movement of the footings to that indicated by the radial lines. The footings 86 and 88 therefore serve to support the unit and to accommodate thermal expansion and contraction during periods of heating and cooling of the generator.

The operation of the herein disclosed unit is as follows. A forced draft fan (not shown) is located at some convenient point near the air inlet of air heater 66. This fan will draw the volume of air necessary for complete combustion of the fuel and develop sufficient pressure to overcome all air and gas side resistances in the unit. The path of air from the forced draft fan is through the air heater 66 and into the plenum chamber 72 formed between the concrete slab upon which the generator rests and the furnace floor 40. In the plenum chamber 72 air is distributed uniformly across the width of the unit before entering the burner wind box 74. Because of the use of the disclosed plenum chamber 72 the need for external duct work in the unit is minimized. The burners 60 distribute finely atomized fuel particles within the turbulent air stream and combustion of the fuel-air mixture occurs within the furnace 18. The combustion gases thus generated are directed against the gas bafile 22 and directed upwardly and then through the superheater 32 located in the gas pass 30 and thence into the boiler bank 20 where they are directed laterally across the boiler bank tubes 28 in three passes formed by refractory bafiies 62 before leaving through the outlet opening 64 provided at the lower end of the boiler bank 20 in the rear wall 14. The gases then pass into the gas inlet duct 68 of the air heater 66 before being discharged through a stack (not shown). Vaporizable fluid in the form of water or the like is supplied to the upper drum 26 from which it is uniformly distributed through the relatively cooler downcomer tubes 28 at the rear of the boiler bank 20 to the lower drum 24. From the lower drum 24 the water is uniformly distributed to the various boiler circuits and furnace steaming circuits by means of supply tubes 48. The density of the steamwater mixture in the circuits is less than the density of the solid water in the boiler downcomer tubes thereby creating the potential needed to circulate the fluid needed within the system. All of the steaming circuits terminate in the upper drum 26 where the steam is collected, separated and discharged into the superheater 32 by means of the connector line 42 where the mixture is heated to the final temperature and thence delivered to the plant piping through an outlet connection 44.

It is contemplated by this invention to form the entire generator enclosure of welded wall construction which eliminates the need for separate skin casing as had heretofore been required in the construction of generators of this type. This elimination of heavy skin casing around the steam generator results in a substantial reduction in generator cost. The welded wall construction is responsible for a further reduction in cost in that it provides in the structure a rigidity that permits the use of floor supports for mounting the unit for expansion and contraction instead of heavy external support beams.

It is also contemplated to form a substantial portion of the generator enclosure as shop-assembled panels. As best illustrated with reference to FIGS. 2 and 3 the units front, rear and side walls 12, 14 and 16 as well as the roof 38 and floor 40 are constructed in this manner. Only the outer end rows 28B of the boiler bank tubes are not formed of panels. These tubes are finned tubes (note FIG. that are erected after the several rows of boiler bank tubes 28 have been assembled. In erecting the tubes 28B, the fins 52 are aligned in abutting relation and a field Weld is applied to connect the fins and form a gas impervious surface. Plates are fitted and welded in the voids formed by the non-linearity of the tubes 28B adjacent the drums so as to complete the enclosure in this portion of the unit.

Constructing the steam generator out of preformed shop-assembled panels is advantageous for several reasons. Firstly, by fabricating the panels in the shop all welds can be heat treated and thereby being rendered more uniform and stronger than field welds. Also, by joining the tubes in the form of panels the number of separate structural members that must be transported and erected is considerably reduced thereby resulting in a substantial reduction in the cost of material handling and erection. Moreover, the use of panels that are preengineered and of standardized dimensions permits a flexibility of design that requires less engineering and is therefore less expensive. Steam generator proportions, which vary from 11 feet to 26 feet deep, 8 feet to 28 feet wide and in three increments of height to suit drum center variables of 28 feet, 30 feet and 32 feet are constructed of these standardized panels. For example the steam generator shown in FIGURE 2 may be made less deep by eliminating the side wall panel indicated as C. Similarly the unit could be made wider by the addition of roof, front wall and floor panels, E, G and J, as Well as appropriate rear wall panels. Therefore, by the use of panel construction a steam generator employing a modular design concept can be adopted.

While the illustrated and described steam generator unit is a preferred embodiment of the present inventive concept it is to be understood that the present description is intended merely to be illustrative and is in no way intended to restrict said inventive concept and that variations and modifications may be made therein without departing from the scope of the invention.

What is claimed is:

1. A floor supported steam generator comprising rectangularly disposed front, rear and side walls including spaced upright tubes to define a furnace and a boiler bank disposed in side-by-side relation and each extending coextensively traversely the entire width of said steam generator; said boiler bank including an upper steam drum,

6 a lower water drum and a plurality of rows of spaced upright tubes connecting said drums; a row of spaced, continuous C-shaped tubes connecting said drums, said C- shaped tubes having relatively long upper and lower leg segments extending later-ally from each of said drums to define the floor and roof of said steam generator and the bight of said C-shaped tubes forming the front wall thereof; metallic filler sufliciently rigid to contain combustion gases within said steam generator welded to and between the adjacent C-sh-aped tubes and the tubes forming the side and rear Walls of the generator so as to render the perimetric surfaces thereof gas tight; a second row of upwardly extending spaced tubes positioned between and separating said furnace and boiler bank and connecting said drums; gas impervious metallic filler welded to and between the tubes of said second row and between the end-most tubes thereof and said side walls to form a partition separating said furnace and said boiler bank and to rigidify said side walls intermediate their ends, said metallic filler extending along said tubes from said lower drum to a level spaced from said roof; space means between the tubes of said second row above said level establishing gaseous communication between said furnace and said boiler bank; and support means engaging the bottom of said steam generator for floor support thereof.

2. A floor supprted steam generator comprising rectangularly disposed front, rear and side walls including spaced upright tubes to define a furnace and a boiler bank disposed in side-by-side relation and each extending coextensively traversely the entire width of said steam generator; said boiler bank including an upper steam drum, a lower water drum and a plurality of parallel rows of spaced upright tubes connecting said drums; a row of spaced continuous C-shaped tubes connecting said drums, said C-shaped tubes having relatively long upper and lower leg segments extending laterally from each of said drums to define the floor and roof of said steam generator, and the bight of said C-shaped tubes forming the front wall thereof; metallic filler sufiiciently rigid to contain combustion gases within said steam generator welded to and between adjacent C-shaped tubes and the tubes forming said side and rear walls so as to render the perimetric surfaces of said generator gas tight; a second row of spaced upright tubes connecting said drums, said row of tubes being laterally extensive across the width of the steam generator intermediate said front wall and said boiler bank; the tubes of said second row being offset forwardly and rearwardly intermediate the height thereof to form a nose baffle extending forwardly toward but spaced from said front wall; gas impervious metallic filler welded to and between the tubes of said second row and between the end-most tubes thereof and said side Walls to form a partition separating said furnace and said boiler bank and to rigidity said side walls intermediate their ends, said metallic filler extending along said tubes from said lower water drum to a level above said nose bafile but spaced from said roof; space means between the tubes of said second row above said metallic filler establishing gaseous communication between said furnace and said boiler bank; and support means engaging the bottom of said steam generator for floor support thereof.

3. A floor supported steam generator comprising rectangularly disposed front, rear and side walls including spaced upright tubes to define a furnace and a boiler bank disposed in side-by-side relation and each extending coextensively traversely the entire width of said steam generator; said boiler bank including an upper steam drum, a lower Water drum and a plurality of parallel rows of spaced upright tubes connecting said drums; a row of spaced, continuous C-shaped tubes connecting said drums, said C-shaped tubes having relatively long upper and lower leg segments extending laterally from each of said drums to define the floor and roof of said steam generator, and the bight of said C-shaped tubes forming the front wall thereof; metallic filler sutficiently rigid to contain combustion gases within said steam generator welded to and between adjacent C-shaped tubes and the tubes forming said side and rear walls so as to render the perimetric surfaces of said generator gas tight; a second row of spaced upright tubes connecting said drums, said row of tubes being laterally extensive across the width of the steam generator intermediate said front wall and said boiler bank; the tubes of said second row being offset forwardly and rearwardly intermediate the height thereof to form a nose baffie extending forwardly toward but spaced from said front wall; gas impervious metallic filler welded to and between the tubes of said second row and between the end-most tubes thereof and said side walls to form a partition separating said furnace and said boiler bank and to rigidify said side walls intermediate their ends, said metallic filler extending along said tubes from said lower water drum to a level above said nose bafiie but spaced from said roof; space means between the tubes of said second row above said metallic filler establishing gaseous communication between said furnace and said boiler bank; and floor mounted support means engaging the bottom of said steam generator solely at substantially the corners thereof for floor supporting said generator. v

4. A floor supported steam generator comprising rectangularly disposed front, rear and side walls including spaced upright tubes to define a furnace and a boiler bank disposed in side-by-side .relation and each extending coextensively traversely the entire width of said steam generato-r; said boiler bank'including an upper steam drum;

extending transversely between said sidewalls, a lower water drum parallel to but spaced from said stearn drum, and a plurality of parallel rows of spaced upright tubes connecting said drums;'a row of spaced continuous C- shaped tubes connecting said drums, said C-shaped tubes having relatively long upper and lower leg segments extending laterally from each of said drums to define the floor and roof of said steam generator, and the bight of said C-shaped tubes forming the front wall thereof; metallic filler sufliciently rigid to contain combustion gases within said steam generator welded to and between adjacent C-shaped tubes and the tubes forming said side and rear walls so as to render the perimetric surfaces of said generator gas tight; a second row of spaced, upright tubes connecting said drums, said row of tubes being laterally extensive across the width of the steam generator for- "wardly of said boiler bank but spaced from said front 'wall; the tubes of said second row having a substantially vertical lower portion and being offset forwardly and said metallic filler establishing gaseous communication between said furnace and said boiler bank; burner means for directing combustion gases through said front wall -dire-ctly opposite and normal to said vertical portion of said partition; superheater means including spaced, parallel rows of U-shaped tubes depending from said roof and positioned above said nose baflle and rearwardly thereof whereby said nose bafiie shields the bends of said U-shaped tubes from the radiant heat of said burners; and support means engaging the bottom of said steam generator for floor support thereof.

5 A floor supported steam generator comprising recrearwardlythereabove to form a nose baffle spaced from said roof and extending forwardlytoward said front wall;

8 tangularly disposed front, rear and side walls including spaced upright tubes to define a furnace and a boiler bank disposed in side-by-side relation and each extending co-extensively traversely the entire width of said steam generator; said boiler bank including an upper steam drum extending, transversely between said side walls, a lower water drum parallel to but spaced from said steam drum, and a plurality of parallel rows of spaced upright tubes connecting said drums; .a row of spaced, continuous C-shaped tubes connecting said drums, said C- shaped tubes having relatively long upper and lower leg segments extending laterally from each of said drums to define the floor and roof of said steam generator, and the bight of said C-shaped tubes forming the front wall thereof; said side walls including vertically parallel tubes; horizontal upper and lower header means extending from said front wall to said boiler bank uniting said vertical tubes in fluid circulation; tubular means connecting said header means and their associated drums; metallic filler sufl'iciently rigid to contain combustion gases Within said steam generator welded to and between said C-shaped tubes and the tubes forming said side and rear walls so as to render theperimetric surfaces of said generator gas tight; a second row of spaced, upright tubes connecting saidjdrums, said row of tubes being laterally extensive across the width of the steam generator forwardly of said. boiler bank but spaced from said front wall; the tubes ofsaid secondrow having a substantially vertical lower portion and being offset forwardly and rearwardly thereabove to form .a nose baffle spaced from said roof and having its apex extending forwardly toward said front wall; gas impervious metallic filler welded to and between the tubes of said second r-ow and between the end-most tubes thereof and said side walls to form a partition separating said furnace and said boiler bank and to rigidify said side walls intermediate their ends, said metallic fille extending along said tubes from said lower water drum to a level above saidnose baffle apex but spaced from said roof; space means between the tubes of said second row above said metallic filler establishing gaseous communication between said furnace and said boiler bank; burner means for directing combustion gases through said front wall directly opposite and normal to said vertical portion of said partition; superheater means including spaced, parallel rows of U-shaped tubes depending from said roof and having their bends located above said nose baflle and rearwardly of its apex therebybeing shielded from the radiant heat of s'aid'burners; and floor mounted support means positioned solely at the corners of said" steam generator including spaced drum saddle means engaging said water drum at its ends and spaced column support means engaging said lower header means at its ends for floor supporting said steam generator.

References Cited by the Examiner UNITED STATES PATENTS 2,293,833 8/42 Kuhner et al. 122-336 2,655,238 10/53 Langvand 122-494 2,749,887 6/56 Olsen 122-494 2,762,635 9/56 Lorber 122-510 2,774,340 12/56 Jankowski 122-510 2,856,907 10/58 Koch 122-478 2,900,174 8/59 Deitrick 122-476 3,003,482 10/61 Hamilton et al. 122-478 3,012,548 12/61 Guszmann 122-494 PERCY L. PATRICK, Primary Exiaminer.

KENNETH W. SPRAGUE, Examiner.

Claims (1)

1. A FLOOR SUPPORTED STEAM GENERATOR COMPRISING RECTANGULARLY DISPOSED FRONT, REAR AND SIDE WALLS INCLUDING SPACED UPRIGHT TUBES TO DEFINE A SURNACE AND A BOILER BANK DISPOSED IN SIDE-BY-SIDE RELATION AND EACH EXTENDING COEXTENSIVELY TRAVERSELY THE ENTIRE WIDTH OF SAID STEAM GENERATOR; SAID BOILER BANK INCLUDING AN UPPER STEAM DRUM, A LOWER WATER DRUM AND A PLURALITY OF ROWS OF SPACED UPRIGHT TUBES CONNECTING SAID DRUMS; A ROW OF SAPCED, CONTINUOUS C-SHAPED TUBES CONNECTING SAID DRUMS, SAID CSHAPED TUBES HAVING RELATIVELY LONG UPPER AND LOWER LEG SEGMENTS EXTENDING LATERALLY FROM EACH OF SAID DRUMS TO DEFINE THE FLOOR AND ROOF OF SAID STEAM GENERATOR AND THE BIGHT OF SAID C-SHAPED TUBES FORMING THE FRONT WALL THEREOF; METALLIC FILLER SUFFICIENTLY RIGID TO CONTAIN COMBUSTION GASES WITHIN SAID STEAM GENERATOR WELDED TO AND BETWEEN THE ADJACENT C-SHAPED TUBES AND THE TUBES FORMING THE SIDE AND REAR WALLS OF THE GENERATOR SO AS TO RENDER THE PERIMETRIC SURFACES THEREOF GAS GITHT; A SECOND ROW OF UPWARDLY EXTENDING SPACED TUBES POSITIONED BETWEEN AND SEPARATING SAID FURNANCE AND BOILER BANK AND CONNECTING SAND DRUMS, GAS IMPERVIOUS METALLIC FILLER WELDED TO AND BETWEEN THE TUBES OF SAID SECOND ROW AND BETWEEN THE END-MOST TUBES THEREOF AND SAID SIDE WALLS TO FORM A PARTITION SEPARATING SAID FURNACE AND SAID BOILER BANK AND TO RIGIDIFY SAID SIDE WALLS INTERMEDIATE THEIR ENDS, SAID METALLIC FILLER EXTENDING ALONG SAID TUBES FROM SAID LOWER DRUM TO A LEVEL SPACED FROM SAID ROOF; SAPCE MEANS BETWEEN THE TUBES OF SAID SECOND ROW ABOVE SAID LEVEL ESTABLISHING GASEOUS COMMUNICATION BETWEEN SAID FURNACE AND SAID BOILER BANK; AND SUPPORT MEANS ENGAGING THE BOTTOM OF SAID STEAM GENERATOR FOR FLOOR SUPPORT THEREOF.

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