US3357408A

US3357408A - Vapor generating apparatus

Info

Publication number: US3357408A
Application number: US480906A
Authority: US
Inventors: Gordon A Patterson
Original assignee: Babcock and Wilcox Co
Current assignee: Babcock and Wilcox Co
Priority date: 1965-08-19
Filing date: 1965-08-19
Publication date: 1967-12-12
Anticipated expiration: 1984-12-12
Also published as: GB1100083A

Description

1967 e. A. PATTERSON 3,

VAPOR 3 ENERATI NG APPARATUS Filed Aug. 19, 1965 2 Sheets-Sheet i INVENTOR. Gordon A. Parferson ATTORNEY 12, 1967 G. A. PATTERSON 3,

VAPOR GENERATING APPARATUS Filed Aug. 19, 1965 2 Sheets-$heet United States Patent 3,357,408 VAPOR GENERATING APPARATUS Gordon A. Patterson, North Canton, Ohio, assignor to The Babcock & Wilcox Company, New York, N.Y., a corporation of New Jersey Filed Aug. 19, 1965, Ser. No. 430,906 9 Claims. (Cl. 122-6) ABSTRACT OF THE DISCLOSURE A reinforcing arrangement for a tubulous wall in a vapor generator, which provides a reinforcing member that extends lengthwise across the wall and between pairs of lugs mounted to the wall, and is retained, by lock members received by the lugs, in a position for abutting contact with the wall to reinforce it is directions perpendicular to its plane, the lugs and lock members being positioned to allow free relative movement between the wall and reinforcing member in directions parallel to the length thereof.

This invention relates to vapor generating apparatus, especially those of the kind having tubulous walls forming part of a furnace chamber and buckstay structure for reinforcing the walls, and more particularly to improved means for connecting the buckstays to the walls.

In conventional buckstay structure of the type set forth a horizontal tie bar supported by an I-beam engages the wall to be braced. The tie bar is held against the outer surface of the wall by pairs of L-shaped clips which are field welded to the wall at horizontally spaced locations along the length of the bar after the latter is positioned. The clips of the conventional structure define with the wall surface a horizontal series of C-shaped retaining devices for connecting the tie bar and the wall, while permitting differential expansive movement of the wall relative to the tie bar. The novel structure of the present invention serves the same purpose, but accomplishes it more simply and more economically by eliminating welding at the assembly site through an arrangement which lends itself to almost complete prefabrication of the wall and the buckstay subassemblies. As a result, it is only necessary to connect the tie bar to the wall by the manual insertion of dowels or pins at the construction site.

According to the present invention the tie bar is connected to a tu-bulous wall by means of lugs and a locking element at each of a number of spaced locations along the length of the bar. At each location where a connection is to be made the horizontal tie bar is received between vertically spaced lugs, each of which has a bight portion projecting horizontally from the wall to receive a manually insertable locking element. The lugs and locking element cooperate to secure the tie bar to the wall.

More specifically, the lugs are preferably U-shaped and preassembled with the wall, the upper and lower lugs being associated in pairs at horizontally spaced locations across the width of the wall to accommodate the tie bar between them. The tie bar is preassembled with an I-beam by being rigidly connected thereto at horizontally spaced locations along the length of the buckstay structure. Final assembly at the construction site involves aligning the tie bar between the associated pairs of lugs and inserting a pin through each pair of lugs to hold the tie 3,357,408 Patented Dec. 12, 1967 bar against lateral movement, e.g., away from the wall. However, the connection between the tie bar and the wall does not interfere with thermal expansion of the wall across its entire width and height.

The various objects, features and advantages of the invention will appear more fully from the detailed description which follows, taken in connection in the accompanying drawings forming in the part of the present invention, and in which:

FIG. 1 is a partial sectional plan view of a fluid cooled combustion chamber incorporating the novel buckstay in accordance with this invention.

FIG. 2 is a vertical sectional view of the connection between the wall and the buckstay, taken along lines 2 2 of FIG. 1, and shown on a greatly enlarged scale.

FIG. 3 is a plan view of the connecting structure shown in FIG. 2.

FIG. 4 is a fragmentary perspective vie-w of assembled apparatus incorporating the present invention, taken at a corner thereof.

FIG. 5 is a horizontal sectional view of modified tubulous wall structure for use on the present invention, shown on an enlarged scale.

FIG. 6 is an elevational view of the structure of FIG. 5.

FIG. 7 is a. vertical sectional view taken along line 77 of FIG. 5.

As shown in the drawings, the illustrated wall construction includes a plurality of wall panels 10 comprising closely spaced upright tubes 12 and intermediate membrane bars 13, joined together to define a furnace chamber 14 for containing hot products of combustion which come into heat transfer relationship with the inner surfaces of the tubes 12. The upper and lower ends of the tubes 12 are connected into a fluid circulation system (not shown). Intermediate the ends of the tubes 12, which may be of considerable extent in some installations, appropriately vertically spaced, horizontally extending tie bars 16 hold the tubes in their preassembled operative relationship to one another, bracing the panels 10 against pressure forces, and in effect forming a band around the periphery of the chamber 14 just as the straps of a keg.

There are one or more tie bars 16 associated with each wall panel 10. Each tie bar 16 is rigidly connected to a reinforcing buckstay 18 consisting of'a' relatively large, horizontally disposed, I-beam. It is the function of the buckstay assembly to prevent buckling of the tubular wall which may occur under any operating conditions, while at the same time permitting relative expansion and contraction of the wall 10 because of their differences in operating temperature. The connection between each tie bar 16 and its associated buckstay 18 is effected at spaced locations along their length by means of buckstay brackets 20 welded or otherwise joined to the inner flange thereof and standoff lugs 22. The latter extend horizontally between the tie bar 16 and the buckstay brackets 20 and are joined thereto as by welding to maintain the tie bar 16 in rigidly spaced relationship with the buckstay 18. As will be explained more fully hereinafter, the tie bar 16, buckstay 18 and buckstay bracket 20 and standofi lugs 22 are preassembled at the factory for assembly at the construction site with the preassembled wall panels 10 in accordance with the present invention.

Referring especially to FIG. 1, each end of a buckstay 18 has connected thereto plates 24 projecting beyond the ends thereof and to which links 26 are pivotally connected by pins 28. The links 26 are also pivotally connected to corner backets 30 by pins 32, in order to allow for expansion of the wall panel 10 relative to the buckstay 18 and thus avoid any possibility of imposing excessive stresses on the aforementioned tubulous wall and buckstay structure. As best seen in FIG. 4, one end of tie bar 16 extends through a vertically elongated slot 34 in an enlarged end portion of its adjacent tie bar; and each end of a tie bar 16 is joined as by welding to the corner bracket 30 of the adjacent buckstay assembly at the construction site to complete the peripheral buckstay construction.

Optionally, the outer surface of each wall panel 10 may be provided with a fiat bearing surface for each tie bar 16 by means of filler bars 36welded in place between neighboring tubes 12, as shown in FIGS. 5, 6 and 7. Preferably the upper and lower ends of the filler bars. 36 are bent inwardly toward the wall panel 10 and a full penetration weld is employed to join the filler bars 36 to the tubes 12 and the membrane bars 13. Filler bars 36 are omitted from the constructions shown in FIGS. 1 to 4.

According to the invention, each wall panel subassernbly includes a horizontal series of vertically spaced pairs of lugs 38. The upper and lower series of lugs 38 are adapted to receive the tie bar 16 between them; and each pair of lugs is further adapted to receive a locking pin 40 in upright position to hold the tie bar 16 in contact with the wall panel 10. Referring now especially to FIGS.2 and 3, each lug 38 is of generally U-shaped cross section to define a curved bight portion 42 intermediate its ends, with its elongated free edge portions joined as by welding to respective neighboring tubes 12 on the outwardly facing surface of wall panel 10. The bight portion 42 of each lug extends horizontally and outwardly of the wall panel 10, well beyond the outer extent of the tie bar 16 as determined by its thickness, so that pin. 40 is snugly received with little or no clearance between the tie bar 16 and the bight portion 42, to thereby connect the tie bar 16 securely to the wall panel 10. For example, with an L-shaped pin 40 of circular cross section having a diam eter of /8 inch it is advisable for such clearance to be in the range of between 0 and inch. The. horizontal upper end portion 44 of the pin 40 makes a 90 angle with its main upright portion so that it serves to limit downward movement of the pin 40 by engagement with the uppermost of each pair of lugs 38.

With this arrangement, each tie bar 16 can be preassembled to its associated buckstay 18 before shipment to the assembly site; and likewise the lugs 38 can be preassembled in the shop with each wall panel 10. Thus, final assembly can be effected by the simple procedure of first fitting each tie bar 16 between the upper and lower rows of lugs 38 and then securing the tie bar in place by manual insertion of the pins 40 into the lugs 38 to produce the connection shown in FIGS. 2 and 3. With the pin 40 received by the bight portions 42 of the lugs 38,

the tie bar 16 is held against lateral movement between the wall panel 10, the lugs 38, and the pin 40 at each location where a connection is made between the tie bar 16 and the wall panel 10.

One advantage of the present invention is that it minimizes the amount of welding required to make the connection by assembly at the construction site under field conditions, and thereby reduces the costs of erecting the vapor generating apparatus. Furthermore, shop-made welds can be made with greater care and accuracy than welds made at the construction site. It will also be noted that the arrangement of the present invention leaves the wall free to undergo thermal expansion across its entire width and height relative to the buckstay assembly, while at the same time providing the furance wall with suitable reinforcement against the pressure forces applied there- I0.

Although the invention has been shown specifically, it will be obvious to those familiar with the art that it is not so limited, but it is susceptable of various changes and modifications without departing from the spirit thereof, as covered by the claims which follow.

What is claimed is:

1. In a vapor generator, the combination of:

(a) a furnace including a row of upright tubes joined together to define a wall,

(b) buckstay structure including a horizontally elongated tie bar for reinforcing said wall,

(c) horizontal series of upper and lower lugs each having a bight portion, said lugs being joined to said wall in vertically spaced pairs adapted to receive said tie bar therebetween for contact with said wall,

(d) and elongated locking means adapted for snug reception in upright position between the bight portions of each pair of lugs and said tie bar whereby said buckstay structure is assembleable with said wall by first positioning said tie bar horizontally between the upper and lower lugs of said series and next inserting said locking means in said lugs tothereby hold said tie bar against lateral movement without restraining'said wall from expansive movement across its width and height relative to said tie bar.

2. In vapor generating apparatus having a wall comprising a row of upright tubes joined together in closely spaced relationship and buckstay structure including a horizontally elongated bar bracing said wall on the outer surface thereof, that improvement for connecting said buckstay structure to said wall at spaced locations along the length of said bar comprising a horizontal series of associated pairs of vertically spaced lugs connected to said. wall adjacent the upper and lower edges of said bar, and a vertically extending pin for each associated pair of lugs adapted to be received thereby in position to hold said bar between said pin, said lugs and said wall.

3. In a vapor generator, the combination of a tubulous wall, an elongated member extending lengthwise across said wall along one side thereof to reinforce said wall in directions generally perpendicular thereto, a plurality of pairs of lug members connected to said wall at locations spaced-apart along the length of said reinforcing member, the lug members of each pair being spaced apart in a direction transverse to the length of said reinforcing member to receive said member therebetween and to allow substantially free movement of said wall relative to said reinforcing member in directions parallel to the length thereof, and, associated with each pair of lug members, a lock member received by both lug members of the pair and supported thereby in extension therebetween for engagement with said reinforcing member to retain said member positioned for abutting contact with said wall to reinforce same.

4. The combination according to claim 3 wherein said lugs each have a bight portion projecting outwardly from said wall, and each lock member is insertably received in the bight portions of its associated lug members.

5. The combination according to claim 3 wherein said tubulous wall includes a plurality of elongated tubes disposed in laterally spaced-apart parallel relation to one another, and said reinforcing member extends lengthwise.

in a direction generally perpendicular to the length direction of said tubes.

6. The combination according to claim 3 wherein said reinforcing member extends lengthwise in a horizontal direction, and the lug members of each pair thereof are disposed in vertically spaced-apart relation to each other with the lower lug member in each pair being disposed for engagement with the lower portion of said reinforcing member and the upper lug member in each pair being disposed for engagement with the upper portion of said reinforcing member.

7. The combination according to claim 5 wherein said reinforcing member is a bar of generally rectangular wall and in underlying relation to said reinforcing bar 5 for fiat surface bearing contact engagement therewith.

'8. The combination according to claim 6 wherein the lug members of each pair thereof are disposed in vertical alignment with each other, and the lock member for each pair of lug members is an L-shaped rod of circular cross section extending at least the full vertical distance from the top of the upper lug member to the bottom of the lower lug member.

9. The combination according to claim 6 wherein nected to the wall at their leg ends to position the bights defined by the bent portions of their U-shapes in outwardly projecting relation to said wall.

References Cited UNITED STATES PATENTS 2,333,777 11/1943 Godshalk 122-6 3,196,842 7/1965 Huge et a1. 122-235 8/1965 Engelhardt 122-6 FOREIGN PATENTS 1,324,336 3/1963 France.

said lug members are generally U-shaped and are con- 15 CHARLES J MYHRE, Primary Examiner.

Claims

1. IN A VAPOR GENERATOR, THE COMBINATION OF: (A) A FURNACE INCLUDING A ROW OF UPRIGHT TUBES JOINED TOGETHER TO DEFINE A WALL, (B) BUCKSTAY STRUCTURE INCLUDING A HORIZONTALLY ELONGATED TIE BAR FOR REINFORCING SAID WALL, (C) HORIZONTAL SERIES OF UPPER AND LOWER LUGS EACH HAVING A BIGHT PORTION, SAID LUGS BEING JOINED TO SAID WALL IN VERTICALLY SPACED PAIRS ADAPTED TO RECEIVE SAID TIE BAR THEREBETWEEN FOR CONTACT WITH SAID WALL, (D) AND ELONGATED LOCKING MEANS ADAPTED FO SNUG RECEPTION IN UPRIGHT POSITION BETWEEN THE BIGHT PORTIONS OF EACH PAIR OF LUGS AND SAID TIE BAR WHEREBY SAID BUCKSTAY STRUCTURE IS ASSEMBLEABLE WITH SAID WALL BY FIRST POSITIONING SAID TIE BAR HORIZONTALLY BETWEEN THE UPPER AND LOWER LUGS OF SAID SERIES AND NEXT INSERTING SAID LOCKING MEANS IN SAID LUGS TO THEREBY HOLD SAID TIE BAR AGAINST LATERAL MOVEMENT WITHOUT RESTRAINING SAID WALL FROM EXPANSIVE MOVEMENT ACROSS ITS WIDTH AND HEIGHT RELATIVE TO SAID TIE BAR.