JP2000290723A - Hearth opening shielding structure of walking beam conveyor type steel heating furnace - Google Patents

Abstract

(57) [Problem] To improve an opening shielding structure of a moving beam post through hole formed in a hearth of a walking beam conveyor type steel heating furnace. The opening shielding structure includes a standing wall made of a refractory material for preventing oxide scale peeled off from a heated steel material carried on a conveyor from being deposited around a moving beam post through-hole (12). 40) is the through hole (12)
Along the periphery of the opening of the moving beam post (2).
The opening shielding cover (30) attached to 1) is attached to the movable beam post (21) at a position above the standing height of the standing wall (40), and the standing wall (40).
It has an area to cover the top surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an opening shielding structure for a through-hole of a moving beam post formed in a hearth of a walking beam conveyor type steel heating furnace.

[0002]

2. Description of the Related Art A heating furnace provided with a walking beam type conveyor mechanism is used as a reheating furnace for steel materials such as slabs introduced into hot rolling, for example. The walking beam conveyor includes a fixed beam and a moving beam. In FIG. 5, (11) is a hearth, (12) is a post through hole (12) formed in the hearth (11), and (20) is a moving beam (a fixed beam is not shown). ing). Post (21) of moving beam (20)
Unlike the fixed beam post (which is fixed upright on the hearth), it is inserted through the through hole (12) of the hearth, extends outside the furnace, and is connected to a lifting drive (not shown). ing. The material to be heated (S) is conveyed in the furnace while being alternately transferred to the moving beam (20) and the fixed beam by the ascending / descending / retracting movement (arrow A) of the moving beam (20).

[0003] The post through hole (12) in the hearth does not prevent the moving beam post (21) from moving up and down and moving back and forth.
It has a substantially elliptical shape that is long in the front-rear direction (the moving direction of the moving beam post 21). The opening area is significantly larger than the cross-sectional area of the moving beam post passing therethrough.
For this reason, an opening shielding cover (30) is attached to the movable beam post (21) as a means for blocking heat radiation from the opening of the post through hole (12) and intrusion of outside air. The cover (30) has a structure in which a heat-resistant alloy member is covered with a refractory layer, and the movable beam post (2) is welded.
Fixed to 1). The durability of the cover (30)
As a measure for improving the stability, as shown in FIG. 6, a refractory plate (ceramic fiber board or the like) (31) is skewered and mounted on a support member (32) made of a heat-resistant alloy. ) Has been proposed which has a structure fixed to the movable beam post (21) by welding.

[0004]

In the furnace operation of the heating furnace, the oxide scale peels off from the surface of the steel material to be heated carried on the conveyor. The peeled oxide scale is
As shown in FIG. 4, it is deposited (H) on the hearth (11) and increases with time. When the scale is deposited on the hearth, the cover (30) attached to the moving beam post (21)
It interferes with the deposits and breaks, and impairs the opening shielding effect (the effect of preventing heat radiation and the intrusion of outside air). Cover (30)
In order to carry out repair / replacement work, the furnace operation must be interrupted, which has a great adverse effect on line operation. SUMMARY OF THE INVENTION The present invention provides an improved hearth opening structure for solving the above-mentioned problems of a walking beam conveyor type heating furnace.

[0005]

In the hearth opening shielding structure of the present invention, a moving beam post through hole (12) is provided in a hearth, and the moving beam post (21) is provided with the post through hole (12). In a walking beam conveyor-type steel heating furnace to which a cover (30) for shielding the opening of the steel plate is attached, it is possible to prevent the oxide scale peeling from the steel material to be heated on the conveyor from being deposited around the post through-hole (12). An upright wall (40) made of a refractory is formed along the periphery of the opening of the through hole (12), and the opening shielding cover (30)
The movable beam post (21) is mounted above the standing wall (40) by the projecting height, and is attached to the standing beam (4).
0) is large enough to cover the top surface.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described with reference to the drawings. In FIG. 1 (a cross-sectional view taken along the line II of FIG. 2) and FIG. 2 (a plan view), (40) is a standing wall made of a refractory and formed around the post through hole (12) in the hearth. It is. Post through hole (12) by standing wall (40)
The accumulation of oxide scale around it is prevented. The deposition (H) of oxide scale near the post through-hole (12) and the penetration into the post through-hole (12) as shown in FIG. 4 are eliminated, so that the oxide scale deposit (H) on the cover (30) is eliminated. It does not cause interference or breakage.

The standing wall (40) is made of, for example, a refractory brick (41).
Are formed by stacking. On the surface of the stacked refractory bricks, castable and other irregular refractory layers (4
If 2) is applied, the standing wall (40) is strengthened, which is effective for preventing damage and extending the life. The height of the standing wall (40)
It is set to an appropriate value in consideration of the scale thickness.
The protruding height of the standing wall from the hearth surface is, for example, 800 to 1
500 m.

The top surface (43) of the standing wall (40) needs to be free of oxide scale deposits. If the oxide scale is deposited, interference between the deposit and the cover (30) occurs, and the cover (30) is damaged as in the case of FIG. In order to prevent this, as shown in FIG. 3, the cover (30) covers the top surface (40) of the standing wall (40) in a region from the advance position (PA) to the retreat position (PB) of the moving beam post (21). 43) is given a size (planar shape) capable of covering the same. The length (L ₃₀ ) of the cover (30) is equal to the length (L) of the upright wall (40).
Slightly larger than the sum of the forward and backward stroke _{(S 21)} of ₄₀₎ and the moving beam post (21), and as shown in FIG. 2, the width _{(W 30)} is slightly than the width _{(W 40)} of the vertical wall (40) It is large. This prevents the oxide scale from falling and accumulating on the top surface (43) of the upright wall (40).

The cover (30) is connected to the upright wall (4) as described above.
0) also serves to prevent the oxide scale from dropping and accumulating on the top surface (43), so that its size (planar shape) is larger than that of the prior art, but the vertical wall (4)
Since only an increase corresponding to the thickness (T ₄₀ ) of (0) is required, the structure for attaching the cover (30) to the moving beam post (21) does not need to be different from the conventional structure.

[0010] With the formation of the upright wall (40) surrounding the post through hole (12), the opening shielding cover (30) attached to the moving beam post (21).
Indicates that the mounting position is the height of the standing wall (40) (approximately 800
(Up to 1500 mm), it is necessary to change the position to the upper side. However, there is no essential restriction on the position change, and it can be easily implemented.

[0011]

According to the present invention, the oxide scale deposition around the hearth opening and the damage to the opening shielding cover can be effectively prevented, and the function of the opening shielding cover can be maintained stably for a long time. This has the effect of reducing maintenance, improving and stabilizing the thermal efficiency of the heating furnace, extending the continuous operation time, and improving the furnace operating efficiency. INDUSTRIAL APPLICABILITY The present invention can be implemented by a simple measure of providing a refractory standing wall at a hearth opening, and is excellent in practical value.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a hearth opening of the present invention.

FIG. 2 is a plan view of a hearth opening of FIG.

FIG. 3 is an explanatory diagram showing a form of a standing wall and a cover in an opening of a hearth of the present invention and a deposition state of oxide scale.

FIG. 4 is an explanatory diagram of a state of depositing oxide scale on a hearth in a conventional heating furnace.

FIG. 5 is a cross-sectional view showing an arrangement of moving beams in a walking beam conveyor-type heating furnace and a manner of attaching a cover.

FIG. 6 is a diagram (a is a plan view, and b is a side view) showing a structural example of a cover attached to the moving beam post.

[Explanation of symbols]

 10: Heating furnace 11: Furnace floor 12: Moving beam post through hole 20: Moving beam 21: Moving beam post 30: Opening shielding cover 31: Refractory plate 32: Heat-resistant alloy support member 33: Mounting bracket 40: Opening Surrounding standing walls 41: Refractory bricks 42: Irregular refractory layer S: Steel material to be heated H: Scale deposit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K034 AA12 AA16 BA08 CA01 EA15 GA02 GA12 GA14 4K050 AA01 BA02 CA09 CA19 CD02 CF14 CG13

Claims (1)

[Claims] 1. A moving beam post through hole (12) in a hearth.
The moving beam post (21) is provided with a cover (30) for covering the opening of the post through hole (12). An upright wall (40) made of a refractory material that prevents the exfoliated oxide scale from accumulating around the post through hole (12) is formed along the periphery of the opening of the through hole (12), and the opening shielding cover ( A walking beam conveyor 30) is attached to the moving beam post (21) at a height above the standing wall (40) and is large enough to cover the top surface of the standing wall (40). Hearth opening shielding structure of a heating furnace.