The furnace of steam boiler has internal pressure which is usually designed ± mm wg. The internal pressure is resisted by attaching buckstay in every. A buckstay arrangement for a furnace of a steam generator wherein the furnace tube walls (12) are supported by a plurality of independent buckstays (10). Sulekha Creative Blog – Buckstays are used in boilers to retain the shape of the furnace against various loads. The name ‘buckstay’ means staying buckling of.
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US4499860A – Furnace buckstay design – Google Patents
Typical dimensions are shown in FIG. Suitable circular holes are provided in each member 34, 36, 38 for these pins 40 to allow for thermal expansion of the wall sections 10, These are optional items and may in most cases be omitted since the deflection in the rods is comparatively small and can be accommodated by the rod itself bending.
However, the present invention would also apply to natural circulation, i. This produces considerable stress in the tubular walls. Accordingly, one aspect of the present invention is drawn to a buckstay system for a membraned-tube wall of a steam generator having a first wall section which meets a second wall section at an angle to form a corner. Tube failures require the boiler to be removed from service which is costly in itself desgin especially so relative to the bucksta lost generation of power.
Again, one or more support rods 20 would be welded between mounting plates 22 on the furnace tube wall 12 to the outward and upward edge of the U-shaped channel beam 72 to support the dead weight of the box beam Additionally, a second elongated plate member 60 may be disposed so as to extend transversely from the lower edge of the outer end member 46 inwardly at an acute angle to meet the central member 42 with the beam The stirrup assemblies are best illustrated in FIGS.
Buckstay has important roles to keep the furnace remain in its position and no bending occurs when the steam boiler operates continuously. Steam boiler plants generally have large furnaces which are commonly constructed of a number of water-cooled tubes welded in side-by-side arrangement to form gas tight tube banks forming the walls of the furnace.
Therefore, it is the object of the present invention to provide a buckstay design wherein the need for a vertical interconnection between adjacent bands of furnace buckstays is not necessary.
Each buckstay 10 comprises an elongated beam 40,70 disposed horizontally adjacent to the tube wall and interconnected therewith and having a cross-section defining therein a buuckstay section 30,30′ whereby the polar moment of inertia of the buckstay 10 is greatly enhanced.
USA – Furnace buckstay design – Google Patents
To minimize the tension in the rods bucksray is desirable that rods expand the same amount as walls 13 and 14 and that rods 26 expand the same amount as walls 15 and Typically, these buckstays are disposed in bands around the parimeter of the furnace tube desig at vertically spaced intervals throughout the height of the furnace wall.
The stirrup connector 22 is free to rotate around the bolts 23 thus providing the necessary movable support.
Although the present invention has been described with reference to the particular embodiment shown in the attached drawings, it is understood that those skilled in the art may make various changes and modifications bucckstay the embodiments shown in the drawings without departing from the true spirit of the present invention. In an alternate embodiment, the buckstay of the present invention may comprise an elongated vertical end plate which is disposed along the furnace tube wall and an elongated U-shaped channel beam mounted to the vertical end plate so as to form a closed rectangular box-like section extending outward from the end plate.
A pair of end connection links 38 is pivotally connected by pins 40 between the end connection corner tie 34 and each end connection buckstay bracket Stirrups hold the buckstays and at a set distance from the walls and bending stops control resign point of bend of the rods. A second extended standoff welded to a bumper plate and also to the tie bar moves in the space between the pads.
Other objects and advantages will become dssign from the following description of an illustrative embodiment of the invention when considered desgin the accompanying drawings wherein:. A brief discussion of the structures to which the present invention is applicable can be had by referring to FIGS.
Boiler buckstay system – The Babcock & Wilcox Company
Therefore, there is no need to provide any vertical members to interconnect the spaced bands of buckstays surrounding the furnace wall as was required in the prior art.
Therefore, the structural support system has a certain amount of inertia which must be overcome before the structural system can flex properly in response to pressure changes within the furnace and thereby absorb the pressure forces acting of the furnace walls.
Two tie bars 31 extend out from the corner 14 along each wall 10, 12 and are welded to each other at the corner The present invention provides a buckstay which has a cross-section having a high polar moment of inertia so that the buckstay itself may absorb bending moments generated by the expansion of the furnace and provides lateral stability. Vapor generator wall buckstay arrangement.
The anti-buckling members 50, 60, 52 and 62 have been described as being elongated plate members.
In a preferred embodiment, two rectangular support plates 42, an upper bukstay and a lower one, are employed above and below buckstays 20, In an buckstya boiler construction, buckstays 20, 22 are repeated at intervals along the vertical height of the wall sections 10, Adjustable buckstay system for vapor generators or the like. As the furnace approaches operating temperature, the furnace walls expand vertically downward as well as tending to dish in a horizontal direction.
As the furnace expands differentially in a vertical direction, each level of buckstays would move a different amount under the influence of the vertical elongation of the furnace tube walls.