JPH03226518A - Method for transporting material to be heated of walking beam furnace and walking beam furnace - Google Patents

Abstract

PURPOSE:To transport a material to be heated without generating skid marks by orthogonally imposing the material to be heated on plural stationary beams and moving beams and moving the moving beams right above, then moving these beams parallel in a diagonal direction. CONSTITUTION:The material to be heated is imposed on the stationary beams 2 and the moving beams 3 in such a manner that the longitudinal direction thereof intersects orthogonally with the beams in the walking beam type heating furnace disposed alternately with the plural beams 2 and 3 in the longitudinal direction of the furnace. The material to be heated is then transported in the furnace by the walking beam action to move the moving beams 3 upward, downward, forward and backward and is heat treated. The walking action to move the moving beams 3 right above from their home positions and further to move the moving beams 3 parallel in the direction B diagonal with the extending direction of the beams from the immediate upward positions A is executed in the above mentioned transporting method. The contact points of the material to be heated and the skids is changed in this way and the generation of the skid marks is prevented. The furnace side walls 1 of the above mentioned furnace are formed along the diagonal direction at the time when the moving beams 3 move by which the radiation of the heat from the furnace body is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention particularly relates to a method for transporting a heated material in a walking beam furnace for reheating slabs and the like for hot rolling, and a walking beam furnace.

[Conventional technology]

In recent years, walking beam furnaces have been used industrially as continuous heating furnaces for hot rolling slabs and the like.

In a walking beam furnace, vertical rectangular movement (
The slab 4 is supported by a moving beam 3 that performs a walking motion and a fixed beam 2 that is always stationary. In addition, each beam is integrally provided with a skid (slab support surface) 6 made of special heat-resistant steel that comes into contact with the slab 4 (see Figure 4). When the slab 4 is placed, it first rises directly above the fixed beam 2 and moves forward by a distance d (see Figure 1), then descends lower than the fixed beam 2, leaving the slab 4 on the fixed beam 2, and then Because the slab 4 is conveyed while repeating a rectangular motion such as moving back by a distance d and returning to the original height, the slab 4 is transported by a distance d, which is called a skid mark, compared to a conventional pusher furnace (in which the slab is slid on a beam). (Skid marks are, for example, the average temperature at the S-3 cross section of the slab 4 and the C-
This refers to the difference from the average temperature in the C section).

[Problem to be solved by the invention]

However, in such a conventional walking beam furnace, the same position in the longitudinal direction of the slab is always in contact with the skid, and the part between the beams that does not come into contact with this skid contact area (for example, the fifth C-C shown in the figure
It was not possible to completely eliminate temperature deviation from the cross-sectional position). Therefore, as a solution to this problem, JP-A-57-17791
As in Publication No. 5, a structure in which the skid has a meandering shape in the direction of the furnace length is disclosed, but with only a combination of straight and meandering skids, it is difficult to use the walking beam compared to the furnace length. Since the distance the slab is moved each time is small, the same part of the slab may be placed on the same skid again during the movement, so skid marks cannot be completely eliminated.

This invention was made in view of these conventional problems, and solves the above problems by moving the moving beam diagonally in parallel at a certain angle with respect to the longitudinal direction of the fixed beam during slab conveyance. It is intended to.

[Means for Solving the Problems] The present invention provides for heating a material to be heated in a walking beam heating furnace in which a plurality of fixed beams and moving beams are arranged parallel to each other and alternately in the furnace length direction. In a method in which the beams are placed so that their longitudinal directions are perpendicular to the two beams and transported in the furnace by a walking motion of the moving beam, the moving beam is moved directly upward from its original position and from the position directly above it to the extended position of the beam. On the other hand, this is a method for transporting a heated material in a walking beam furnace in which the material is moved in parallel in an oblique direction.

In addition, as a heating furnace for suitably carrying out the above-mentioned conveyance method,
This is a walking beam furnace in which the side wall of the furnace is formed along the diagonal direction when the moving beam moves diagonally in parallel from a position directly above its original position.

[Effect]

In this invention, since the above-mentioned configuration is adopted, the moving beam is moved in the longitudinal direction of the fixed beam when conveying the slab.
By moving diagonally in parallel at a certain angle,
Each time the moving beam performs a walking operation, the contact portion of the heated material with each beam is different, so skid marks are hardly a problem in this method of transporting the heated material.

In addition, because the side wall of the furnace is formed along the diagonal direction when the moving beam moves diagonally in parallel from the position directly above its original position, the conveyance direction of the heated material and the furnace length direction are different. This is suitable for carrying out the method for conveying the heated material described above.

〔Example〕

The present invention will be explained below based on the drawings. 1st, 2nd
The figure is an explanatory diagram of the heated material conveying method according to the present invention, and the third
The figure is a schematic plan view of an embodiment of a walking beam furnace suitable for carrying out this method.

1st. In Fig. 2, 1 indicates the side wall of the furnace, 2 is a fixed skid (fixed beam), and 3 is a moving skid (moving beam), and the beams are arranged parallel to each other and alternately at predetermined intervals. has been done. In addition, each beam 2.3 is made of special heat-resistant steel as shown in Figure 4 (A), (
A skid 6 having the shapes shown in (b) and (c) is integrally provided to form a support surface for the heated material.

Here, the walking operation of the moving beam 3 will be explained.

The movable beam 3 transports the slab (heated material) 4 while repeating vertical rectangular movements from the original position, such as ascending, moving forward, descending, retreating, and returning to the original position. By translating in the diagonal direction by θ, the position where the slab 4 contacts the fixed beam 2 after advancing is shifted by S −5 in−′θ compared to before advancing. Here, S indicates the amount of advance of the moving beam 3 in the diagonal direction. Therefore, if n rectangular movements, that is, walking movements, are performed from the charging port to the extraction port of the heating furnace, the longitudinal direction of the slab 4 will be n s −5 in −′θ relative to the fixed beam 2. It will be shifted from the In addition, as for the range of θ, it is desirable to set l≦n s −5 in −′θ, where the distance between the beams is l, but since the width of the skid 6, which is the slab support surface, is small (see Figure 4). ), the effect can be expected even if l>nS·sin −'θ.

Further, in this embodiment, considering the furnace efficiency, the furnace wall is also inclined at an angle θ with respect to the fixed beam 2 in accordance with the arrangement of the beams, but the furnace wall does not necessarily have to be inclined. In addition, it is desirable for the angle θ to be set so that the slab moves by one beam or more from charging to extraction in order to reduce skid marks. is desirable from a facility planning perspective.

Fig. 2 shows the state of slab movement according to the present invention; Fig. 2 (a) shows the state when the slab 4 is charged into the furnace, and Fig. 2 (b)
Figure (C) shows the slab moved to the middle position of the furnace.
is the state in which the slab has reached the extraction port, and the amount of longitudinal movement of the slab at this time is about one beam.

Figure 3 shows an embodiment of a walking beam furnace according to the present invention, and its configuration is such that fixed beams and moving beams are alternately arranged at 1 m intervals in a furnace with a length of 30 m and a width of 13 m. . The oblique angle θ of the moving beam is θ=t
an -'-(-1,91"> 0, and for example, the end position in the longitudinal direction of the slab corresponding to the N-th beam at the time of charging gradually approaches the N-1st beam during conveyance in the furnace. , it will be on the N-1th beam at the time of extraction.The walking beam travel distance is 6005W in the furnace length direction and 20 meters in the furnace width direction, and the skid is 20m for each stroke of the walking beam.
There will be a shift. Further, the walking beam may be driven by a known method (for example, using an eccentric cam), but it goes without saying that the walking beam is driven in a direction inclined by an oblique angle θ with respect to the furnace length direction.

The side walls of the furnace are also set at an oblique angle θ to reduce heat dissipation from the furnace body.
It is tilted with respect to the furnace length direction. In addition, the combustion burner may be designed so that the temperature distribution in the width direction of the slab is uniform, and when a side burner is used, the frame is made to extend at right angles to the fixed beam.

[Effects of the Invention] As explained above, according to the present invention, since the position of the skid in contact with the slab changes each time the slab is transported, skid marks can be significantly reduced compared to the conventional walking beam furnace.

Further, since the furnace according to the present invention has its side wall inclined with respect to the fixed beam by the oblique angle θ, it is possible to obtain the effect of reducing heat dissipation in the furnace body.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the operation of the moving beam according to the present invention, and Fig. 2 is an explanatory diagram of the movement of the heated object in the longitudinal direction by the moving beam according to the present invention. (C) shows the state when the heated object has moved into the furnace, and (C) shows the state when the heated object has reached the extraction port. Fig. 3 is an embodiment of the walking beam furnace according to the present invention. Schematic diagram showing the fourth
The figure is a partial perspective view of each beam provided with various skids, such as ((), (II), (n), etc.), and FIG. 5 is an explanatory diagram of skid marks.

Claims (2)

[Claims] (1) A material to be heated is placed in a walking beam heating furnace in which a plurality of fixed beams and a moving beam are arranged in the furnace length direction, and the material to be heated is placed so that its longitudinal direction is orthogonal to both beams, and the moving beam In the method of conveying in the furnace by a walking motion, the moving beam is moved directly upward from its original position, and from the directly above position, the moving beam is caused to move in parallel in an oblique direction with respect to the extending direction of the moving beam. A method for transporting heated materials in a walking beam furnace. (2) A walking beam furnace characterized in that the side wall of the furnace is formed along the diagonal direction in which the moving beam moves diagonally in parallel from a position directly above its original position.