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
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.
At the time of application buckstay is attached to tie bar with slip connection to give limitation of deflection inward and outward of furnace wall tubes. A third standoff’s upper and lower ends are received within the apertures formed by the other U-shaped plates on the upper and lower support plates and engaged by the engagement means with its associated buckstay. Design Buckstay in the Steam Boiler.
Some buckstay and membraned-tube wall attachment structures are disclosed in U. Therefore, the structural support system has a certain amount deskgn 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. Horizontally, the ubckstay 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.
Filler bars 44 may be welded inbetween adjacent tubes 16, on top of the membrane 18, to provide for greater surface area for welding dssign plural support plates 42 to the tubes 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.
The invention as set forth in claim 8 and further including bending stops positioned between said retaining means and said ends of said rod means to control the point at which said rod means bend outwardly. 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. In accordance with the present invention, an antibuckling member 50,60 is mounted to the elongated channel beam 40 so as to extend transversely across one of either the upwardly facing channel 32 or the downwardly facing channel 34 of the elongated channel beam 40 so as to form a box-like section 30,30′ within the I-beam cross-section of elongated channel beam It is a constant goal of boiler makers and the utility industry to improve the availability of their power generation equipment.
Alternatively, as shown in FIG.
Design of Buckstays | Sulekha Creative
In the present invention, however, the rods instead of the tubular walls will take the stresses which are being applied to the buckstay assemblies. As previously pointed out the buckstay assemblies must be supported for movement relative to the tubular walls because of the difference in thermal expansion between the members. Since the furnace walls will expand more than the buckstay assemblies, the offset ends of the stirrup assemblies will pass through a dead center position and come to rest in the hot position offset by the same amount in the opposite direction from when cold if properly adjusted.
For better understanding of the invention, its operating advantages and specific results attained by it uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention buckkstay illustrated. In the embodiment of the dexign of the present invention shown in FIGS. This is best illustrated huckstay FIG.
The large expanses of tubular nuckstay in such furnaces form membranes which are subjected to considerable forces particularly when the furnaces are pressure fired. The illustrated stirrups as well as the brackets to anchor the ends of the rods to the buckstays are only shown by way of example and many other types of each could be employed in the present invention.
The stirrup assembly 20 is the same as stirrup assembly 19 except that plates 24 are welded between brackets 21 as shown in FIG. A brief discussion of the structures to which the present invention is applicable can be had by referring to FIGS. Two pads are welded to and spaced from each other on top of each support plate, and a U-shaped plate is welded on top of each pad sesign form an aperture.
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.
US3203376A – Buckstay arrangement for furnace walls – Google Patents
In desivn embodiment of the present invention, the buckstay comprises an elongated channel beam having a horizontally disposed central member bckstay first and second vertically disposed end members extending along the lateral edges of the central member so as to form buckshay I-beam cross-section.
US USA en For example, all four of the buckstays could be truss assemblies or all four could be simple I beams. These are optional items eesign 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, since the rods are outside of the tubular walls they will be cooler than the average Wall temperature and since they are not and cannot be fastened throughout their length to the walls according to this invention, they will not expand as much as the walls. 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 tube walls are generally supported from the top of the structural framework of the steam generating plant.
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 In an actual boiler construction, buckstays 20, 22 are repeated at intervals along the vertical height deaign the wall sections 10, The second plate member 60 is welded at its respective interfaces with the outer end member 46 and the central member 42 of the beam 40 to form a second triangular box-like section to further enhance the polar moment of inertia of the buckstay A buckstay system according to claim 1, wherein two such anchor assemblies are provided at the corner for each buckstay, one being located above and the other below each buckstay.
The buckstay of the present invention is characterized by a cross-section comprising a box-like section having a high polar moment of inertia. Referring now buckdtay the drawings, and more particularly to FIGS. The buckstays are customarily connected to the walls by any one of a variety of mean so that the forces on the walls will be transferred to the load sustaining buckstays.