Bracing device for an annealing furnace

Abstract

 A bracing device includes an annular tie-up plate (3) and a plurality of packing members (4) to tie up individual posts (151, 152) which are used to support modular diffusers (161) of an annealing furnace (1). The tie-up plate (3) has a plurality of inner tubular surfaces (351) respectively defining bores (35) for passage of posts (151,152) respectively therethrough. Each packing member (4) is disposed between the inner tubular surface (351) and the corresponding post (151,152) to prevent relative movement between the inner tubular surface (351) and the corresponding post (151,152), thereby holding the tie-up plate (3) firmly between a furnace base (11) and the diffusers (161). A plurality of spacers (6) are disposed between the tie-up plate (3) and the base (1) so as to secure the tie-up plate (3) at a height position.

Description

[0001] This invention relates to a batch annealing furnace, more particularly to a bracing device adapted to tie up individual posts that are used to support grouped modular diffusers of the batch annealing furnace.

[0002] A thermal treatment process is generally applied to a steel product in a steel works in order to enhance the mechanical property of the product. Referring to Figs. 1 and 2, plural stacked steel coils 100 are placed in a batch annealing furnace 1 (i.e., a kind of thermal treatment furnace), and are heated to 800 °C or more to enhance the surface quality and mechanical property of the steel coils 100 so as tomeet the requirements of customers. The annealing furnace 1 includes a base 11, a motor-driven fan 12 disposed at a center of the base 11, and a hood 13 disposed to cover the base 11. The hood 13 and the base 11 cooperatively define an accommodation chamber 14 for accommodating the steel coils 100. A support unit 15 includes eight inner posts 151 surrounding a central axis of the base 11 and secured on the base 11 by individual screw fasteners 10, and eight outer posts 152 surrounding the central axis of the base 11 and secured on the base 11 by individual screw fasteners 10. A carrier unit 16 includes four diffusers 161 which are angularly displaced from one another about the central axis and each of which is supported on two of the inner posts 151 and two of the outer posts 152, and a carrier plate 162 which is disposed on the diffusers 161 and on which the steel coils 100 are rested. A refractory material 17 is disposed around the posts 151, 152. A plurality of deflection plates 18 are secured on the diffusers 161 for facilitating flowing of furnace gases.

[0003] Since the carrier plate 162 on which the bulky steel coils 100 are rested is supported on the separate diffusers 161, and since each of the diffusers 161 is supported by the separate inner and outer posts 151, 152 that are secured on the base 11 by the individual screw fasteners 10, the inner and outer posts 151, 152 will be subjected to a shear force during placement of the steel coils 100 on the carrier plate 162, which may cause breaking of the screw fasteners 10, and displacement of the diffusers 161 toward or away from the central axis of the base 11. Hence, the occlusion of the hood 13 to the base 11 would be adversely affected, and the diffusers 161 may collide with blower blades of the fan 12.

[0004] An object of the present invention is to provide a bracing device which can tie up individual posts that are used to support grouped modular diffusers of an annealing furnace so as to enhance the strength of the posts and to reduce cost of maintaining the furnace.

[0005] According to this invention, the bracing device includes an annular tie-up plate and a plurality of packing members. The tie-up plate has upper and lower major surfaces normal to a centerline of an annealing furnace that extends in an upright direction, and a plurality of inner tubular surfaces respectively defining a plurality of bores which extend along respective axes through the upper and lower major surfaces and which are angularly displaced from one another about the centerline. Each bore is configured to permit passage of a top end of one of inner and outer posts that are secured on a furnace base for supporting a plurality of modular diffusers. Each packing member is disposed between one of the inner tubular surfaces and a corresponding one of the inner and outer posts, and is configured to prevent relative movement between the respective one of the inner tubular surfaces and the corresponding one of the inner and outer posts, thereby holding the tie-up plate firmly between the base and the diffusers. Further, a plurality of spacers are disposed between the tie-up plate and the base, and extend in the upright direction so as to secure the tie-up plate at a height position relative to the base.

[0006] Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment of the invention, with reference to the accompanying drawings, in which:

Fig. 1 is a fragmentary sectional view of a conventional annealing furnace;

Fig. 2 is a perspective view showing a support unit and a carrier unit of the conventional annealing furnace;

Fig. 3 is an exploded perspective view of a bracing device in accordance with a preferred embodiment of this invention;

Fig. 4 is a perspective view showing the bracing device according to the preferred embodiment of this invention mounted on a support unit; and

Fig. 5 is a sectional view of the bracing device according to the preferred embodiment of this invention in use.

[0007] Referring to Figs. 3 to 5, the preferred embodiment of a bracing device according to the present invention is adapted to tie up individual posts 15 that are used to support grouped modular diffusers 161 of a batch annealing furnace 1. The batch annealing furnace 1 includes a base 11, a hood 13 which has upper and lower inner wall regions 131,132 that surround a centerline (L) normal to the base 11, which is disposed to cover the base 11, and which is in fluid tight engagement with the base 11 for receiving a charge 100 to be heat treated, such as steel coils 100, and a fan unit 12 disposed to force furnace gases to flow along an outwardly and radially extending flow path which is spaced apart from the base 11, and which is directed towards the lower inner wall region 132 such that the furnace gases are heated by an external heating source before flowing upwards to heat treat the charge 100. The annealing furnace 1 further includes a carrier unit 16 which includes the modular diffusers 161 and a carrier plate 162. With reference to Fig. 2, the modular diffusers 161 surround the fan unit 12. Each modular diffuser 161 includes a bottom wall 163 which has inner and outer edges 164, 165 that extend angularly about the centerline (L), and leading and trailing edges 166,167 that are angularly opposite to each other, leading and trailing walls 168,169 which extend respectively from the leading and trailing edges 166, 167 in an upright direction such that the leading wall 168 is in abutment with the trailing wall 169 of an adjacent one of the diffusers 161, and such that the bottom walls 163 of the diffusers 161 cooperatively form a surrounding platform 19 which is elevated to be spaced apart from the base 11, and which has inner and outer circumferential zones 191,192 proximate to the inner edges 164 and the outer edges 165, respectively, and front and rear guiding walls 160 which extend upwardly from the bottom wall 163, and which define a guiding channel 14 therebetween to serve as the flow path. The annealing furnace 1 further includes a plurality of inner posts 151 which are displaced angularly from one another about the centerline (L), and each of which has an inner bottom end secured to the base 11 by means of screw fasteners, and an inner top end disposed under and abutting against the inner circumferential zone 191, and a plurality of outer posts 152 which are displaced angularly from one another about the centerline (L), and each of which has an outer bottom end secured to the base 11, and an outer top end disposed under and abutting against the outer circumferential zone 192. Thus, each diffuser 161 is supported by two inner posts 151 and two outer posts 152. In addition, the annealing furnace 1 further includes a refractory material 17 disposed around the posts 15, and a plurality of deflection plates 18 secured on the diffusers 161 for facilitating flowing of the furnace gases.

[0008] According to this embodiment, the bracing device comprises an annular tie-up plate 3, a plurality of packing members 4 (eight in this embodiment), and a plurality of spacers 6 (six in this embodiment).

[0009] The tie-up plate 3 has an upper major surface 31, a lower major surface 32 opposite to the upper major surface 31 in the upright direction, an inner peripheral surface 33 joining the upper and lower major surfaces 31,32 and surrounding the centerline (L), and an outer peripheral surface 34 joining the upper and lower major surfaces 31, 32 and radially opposite to the inner peripheral surface 33, and a plurality of inner tubular surfaces 351 respectively defining a plurality of bores 35 which extend along respective axes through the upper and lower major surfaces 31,32 and which are angularly displaced from one another about the centerline (L). The bores 35 are configured to permit passage of the inner top ends of the inner posts 151 respectively therethrough. The tie-up plate 3 further has a plurality of outer gaps 361 which extend in the upright direction through the upper and lower major surfaces 31, 32, and which extend from the outer peripheral surface 33 toward the inner peripheral surface 34, and a plurality of inner gaps 362 which extend in the upright direction through the upper and lower major surfaces 31, 32, and which extend from the inner peripheral surface 34 toward the outer peripheral surface 33.

[0010] Each packing member 4 is disposed between the respective inner tubular surface 351 and the corresponding inner post 151. Specifically, each bore 35 is configured such that the inner tubular surface 351 is spaced apart from the corresponding inner post 151 by a tubular clearance. Each packing member 4 includes two shell halves 41 which are diametrically opposite to each other and which are separated from each other, and which extend angularly about the axis of the respective bore 35, and two upper flanges 42 which extend radially, outwardly, and respectively from upper ends of the shell halves 41. The shell halves 41 of each packing member 4 are inserted into the tubular clearance between the respective inner tubular surface 351 and the corresponding inner post 151, and the upper flanges 42 of each packing member 4 are rested on the upper major surface 31 so as to prevent relative movement between the respective inner tubular surface 351 and the corresponding inner post 151, thereby holding the tie-up plate 3 firmly between the base 11 and the surrounding platform 19.

[0011] Each spacer 6 is in the form of a screw bolt 6 extending in the upright direction, and has an upper end threadedly engaging a screw hole 5 which is formed in the tie-up plate 3, and a lower end abutting against the base 11 so as to secure the tie-up plate 3 at a height position relative to the base 11.

[0012] Alternatively, the tie-up plate 3 may be disposed to tie up the outer posts 152.

[0013] As illustrated, some of the advantages of the bracing device according to this invention are:

1. The bracing device of this invention can be used to tie up individual posts 151 and is held between the base 11 and the surrounding platform 19 constituted by the modular diffusers 161. The inner and outer posts 151, 152 can support firmly the diffusers 161 and withstand the shear force that are generated as a result of uneven loading of the steel coils 100. Thus, the overall structural strength of the posts 151, 152 can be increased, and the maintenance cost of the annealing furnace can be reduced.

2. The provision of the inner and outer gaps 361,362 can accommodate changes in size of the tie-up plate 3 during a thermal treatment process.

Claims

1. A bracing device adapted to tie up individual posts (151,152) that are used to support a plurality of modular diffusers (161) of an annealing furnace (1) which includes a base (11), a hood (13) which has upper and lower inner wall regions (131,132) that surround a centerline (L) normal to the base (11), which is disposed to cover the base (11), and which is in fluid-tight engagement with the base (11) for receiving a charge (100) to be heat treated, and a fan unit (12) disposed to force furnace gases to flow along an outwardly and radially extending flow path which is directed towards the lower inner wall region (132) such that the furnace gases are heated before flowing upwards to heat treat the charge (100),
the modular diffusers (161) being disposed to surround the fan unit (12), each of the modular diffusers (161) including
a bottom wall (163) which has inner and outer edges (164,165) that extend angularly about the centerline (L), and leading and trailing edges (166,167) that are angularly opposite to each other,
leading and trailing walls (168,169) which respectively extend from the leading and trailing edges (166,167) in an upright direction such that the leading wall (168) is in abutment with the trailing wall (169) of an adjacent one of the diffusers (161), and such that the bottom walls (163) cooperatively form a surrounding platform (19), the surrounding platform (19) having inner and outer circumferential zones (191,192) proximate to the inner edge (164) and the outer edge (165), respectively, and
front and rear guiding walls (160) which extend upwardly from the bottom wall (163), and which define a guiding channel (14) therebetween to serve as the flow path,
the annealing furnace (1) further including a plurality of inner posts (151) and a plurality of outer posts (152) serving as the individual posts, the inner posts (151) being displaced angularly from one another about the centerline (L), each of the inner posts (152) having a bottom end secured to the base (11), and a top end which is disposed under and which abuts against the inner circumferential zone, the outer posts (152) being displaced angularly from one another about the centerline (L), each of the outer posts (152) having a bottom end secured to the base (11), and a top end which is disposed under and which abuts against the outer circumferential zone, characterized in that:
said bracing device comprises:
an annular tie-up plate (3) which has an upper major surface (31), a lower major surface (32) opposite to said upper major surface (31) in the upright direction, an inner peripheral surface (33) joining said upper and lower major surfaces (31,32) and surrounding the centerline (L), an outer peripheral surface (34) joining said upper and lower major surfaces (31,32) and radially opposite to said inner peripheral surface (33), and a plurality of inner tubular surfaces (351) respectively defining a plurality of bores (35) which extend along respective axes through said upper and lower major surfaces (31,32) and which are angularly displaced from one another about the centerline (L), each of said bores (35) being configured to permit passage of the top end of one of the inner and outer posts (151, 152) therethrough; and
a plurality of packing members (4), each disposed between a respective one of said inner tubular surfaces (351) and a corresponding one of the inner and outer posts (151,152), and configured to prevent relative movement between the respective one of said inner tubular surfaces (351) and the corresponding one of the inner and outer posts (151,152), thereby holding said tie-up plate (3) firmly between the base (11) and the surrounding platform (19).

2. The bracing device according to Claim 1, characterized in that said bores (35) are configured such that each of said inner tubular surfaces (351) is spaced apart from the corresponding one of the inner and outer posts (151,152) by a tubular clearance, each of said packing members (4) being configured to be inserted into said tubular clearance.

3. The bracing device according to Claim 2, characterized in that each of said packing members (4) includes two shell halves (41) which are diametrically opposite to each other, which extend angularly about the respective axes, and which are inserted into said tubular clearance between the respective one of said inner tubular surfaces (351) and the corresponding one of the inner and outer posts (151,152), and two upper flanges (42), each of which extends radially and outwardly from an upper end of a respective one of said shell halves (41) and is rested on said upper major surface (31).

4. The bracing device according to Claim 3, characterized in that said two shell halves (41) are separated from each other.

5. The bracing device according to Claim 1, characterized in that said tie-up plate (3) further has a plurality of outer gaps (361) which extend in the upright direction through said upper and lower major surfaces (31,32), and which extend from said outer peripheral surface (33) toward said inner peripheral surface (34), and a plurality of inner gaps (362) which extend in the upright direction through said upper and lower major surfaces (31,32), and which extend from said inner peripheral surface (34) toward said outer peripheral surface (33).

6. The bracing device according to Claim 1, further characterized by comprising a plurality of spacers (6) which are disposed between said tie-up plate (3) and the base (11) and which extend in the upright direction so as to secure said tie-up plate (3) at a height position relative to the base (11).

7. The bracing device according to Claim 5, characterized in that each of said spacers (6) has an upper end threadedly engaging said tie-up plate (3) and a lower end abutting against the base (11).

Drawing