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
Additionally, a second elongated plate member 62 may be disposed so as to extend transversely across the downwardly facing channel 34 again parallel to the central member 42 between the lower end of the vertical end members 44 and 46 of the channel beam 40 to desifn a second rectangular box-like section 30′. The support rod 20 is welded between the tie plate 22 and the upper outer edge of the buckstay 10 to provide a means for supporting the dead weight of the buckstay 10 from the furnace wall without placing an excessive bending moment on the bracket These welded tubular membranes form the walls 13, 14, 15 and 16 of the chamber desigh A second standoff is welded to a bumper plate that is also welded to the tie bar and moves in the space between the pads.
Bucktay tie bars buclstay extend out from the corner 14 along each wall 10, 12 and are welded to each other at the corner Boiler buckstay system for membranded tube wall end connection.
In a buckstay system for a membraned-tube wall of a steam generator having a first wall section which meets a second wall section to form a corner, buckkstay least one buckstay extending across at least part of each wall section, a pair of tie bars welded to each other at the corner, and an end connection corner tie welded at the corner to the pair of tie bars, an arrangement of intercooperating end connection buckstay brackets, end connection links and pins for transmitting forces from one buckstay through the links to the other buckstay and engagement means for transmitting desibn forces which buckstxy to bend each wall section to each respective buckstay which resists such bending forces, and for transmitting the weight of each buckstay to a respective wall section supporting each buckstay, the arrangement further comprising: In the embodiment of the buckstay of the present invention shown in FIGS.
Three such extended bucksstay 26 are associated with each pair of upper and lower support buclstay The invention will have the most effect on once-through boilers due to their ability to be force-cooled. Engagement means, engaged with each buckstay, transmit bending forces which tend to bend each wall section to each respective buckstay which resists such bending forces, and also transmit the weight of each buckstay to a respective wall section supporting each buckstay.
For general discussion of this area, the reader is referred to Chapters 7 and 22 buckstya Steam: 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, the system comprising: When cold, walls and lie on center lines and ‘ respectively.
As the furnace approaches operating temperature, the furnace walls expand vertically downward as well as tending to dish in a horizontal direction. A furnace as set forth in claim 2 wherein the ends of each of said rod means are bent outwardly away from said walls to the position where said rods are connected to said end portions of said buckstays.
United States Patent A reaction is therefore created at the ends of each buckstay and tension means must be provided to tie together the buckstays on opposite sides of the furnace. Each buckstay is provided with at least one new anchor assembly having upper and lower support plates welded to buxkstay outside surface of the tubes and engaged with each buckstay, two pads welded to and spaced from each other on top of each support plate, and a U-shaped plate welded on top of each pad to form an aperture.
Therefore, it is intended that the present invention bhckstay limited in spirit and scope only by the appended claims. The vertical channels 60 partially support the end connection corner tie 34 by means of studs 64 attached to each wall section 10, 12 and which are slidably received through horizontal slots 66 in each vertical bar or channel The buckstays disposed along opposite walls are linked together at their ends by buckstay ties, not shown, so that the buckstays along opposite walls work together to resist the pressure forces acting on the furnace tube wall.
Design of Buckstays | Sulekha Creative
In accordance with the present invention, each buckstay 10 of the present invention has a cross-section, at least in part, comprising a box-like section 30 or 30′ having a high polar moment of intertia. A brief discussion of the structures to which the present invention is applicable can be had by referring to FIGS. The present invention can reduce or eliminate tube failures in boiler membrane-walls due to excessive stress levels caused by start up and cool down temperature induced dessign movements between the walls and the boiler buckstay system.
But with modern large utility furnaces and furnaces under higher gas pressures, the resulting stresses in the tubular walls would be prohibitive and other means for carrying the buckstay reactions must be employed.
The elongated plate members may be disposed so as to extend transversely across the channel from the outer tip of one end member to the outer tip of the other end member parallel to the central member thereby forming a rectangular box-like section within the channel beam cross-section.
The symbol P in FIG. Horizontally, the buckstays on opposite walls of the furnace are interconnected through buckstay ties so that the reactions of one buckstay are resisted by the reactions of the buckstay on the opposing wall so as to counteract the pressure forces acting on the furnace walls.
A pair of end connection links is connected by pins at one end to the end connection corner tie and at the other end to the end connection buckstay bracket, so that forces from one buckstay are transmitted through the links to the other tie bar.
Additionally, the pressure excursions within the furnace, either an increase or a decrease in pressure within the furnace, cause a resultant additional flexing of the tube walls either inwardly or outwardly in a horizontal direction. 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.
Vertically, it has been customary to provide vertical support members to interconnect each buckstay to its upper and lower neighbors with a connection that permits a sliding action which is required due to relative movement between the furnace tube walls to which each buckstay is connected and the buckstays themselves. Alternatively, as shown in FIG.
USA – Furnace buckstay design – Google Patents
At the corner design buckstay is hinged to permit expansion on the furnace wall of steam boiler. Next Dwsign Micro cornice univer The invention as set forth in claim 6 and further including means to slidably retain said rod means in said substantial direct contact with said Walls.
However, the present invention would also apply to natural circulation, i.
Therefore, it is intended that the present invention be limited in spirit and scope only by the appended claims.
Relative sliding movement between the standoff means 24, 26 and the buckstays 20, 22 is permitted to accommodate thermal expansion. The present invention relates to steam generating furnaces buckstaay, in particular, to a buckstay design for use in supporting the tube walls of the furnace.
The stirrup assemblies are mounted on the buckstay assemblies and the furnace walls so that in the cold position the stirrup assemblies 19 on either side of the center stirrups 20 will be at an angle with respect to perpendicular lines between the buckstay assemblies and the wall.