JP2000273534A - Slab supporting method in vertical induction heating furnace, and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slab supporting method for a vertical induction heating furnace that the local temperature drop is reduced on the slab side, and its device. SOLUTION: A vertical induction heating furnace comprising an elevating/ lowering furnace 3 which is elevated/lowered in the vertical direction with a slab S placed therein with its width in the vertical direction, a plurality of slab upper side supporting devices 4-7 to support the upper side surface of the slab S in the longitudinal direction from an upper part, and an induction heating coil arranged on a side wall of a furnace body 1 to heat the slab, is provided with an operation cycle setting device 11 to set the time when tip pieces 4b-7b of the slab upper surface supporting devices 4-7 are brought into contact with the upper side surface of the slab and its operational order, and a slab upper surface supporting device operation control device 10 to control the elevating/lowering operation of the slab upper surface supporting devices 4-7 successively and alternately one by one.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method and an apparatus for supporting a slab in a rigid induction heating furnace.

[0002]

2. Description of the Related Art In a conventional rolling mill, for example, when heating an extremely thick slab, the slab is heated in an ordinary continuous heating furnace and then charged into a rigid induction heating furnace to be reheated. As shown in FIGS. 5 and 6, such a rigid induction heating furnace is provided on a side wall 1a of a furnace body 1 and has a plurality of induction heating coils 2 for heating a slab S, and is capable of vertically moving up and down in the furnace. And a plurality of, for example, four units arranged on the ceiling 1b of the furnace body 1 at predetermined intervals in the longitudinal direction of the slab S, that is, a first slab upper surface support device 4 and a second slab upper surface support It comprises a device 5, a third slab upper surface support device 6, and a fourth slab upper surface support device 7. For example, an air cylinder or the like is used for each of the first to fourth slab upper surface support devices 4 to 7.

[0003] A mounting hardware 3 a for supporting the slab S is mounted on the upper surface of the elevating hearth 3. At the ends of the piston rods 4a to 7a of the first to fourth slab upper surface support devices 4 to 7, hollow tip metal members 4b to 7b made of, for example, heat-resistant metal are attached, respectively. In order to suppress heat conduction from the slab S heated to a high temperature, cooling is performed on cooling water supplied through piping (not shown).

Then, the slab S in a horizontal state heated by a normal continuous heating furnace (not shown) is turned into a turning device (not shown).
The slab S is then placed on the elevating hearth 3 after the orientation of the slab S is lowered, and the longitudinal direction of the upper surface of the slab S that has been stiffened is simultaneously lowered from the top by the metal fittings 4b. After contacting and supporting 7b, the elevating hearth 3 is raised to near the side wall 1c, and the slab S is inserted into the furnace. Thereafter, the induction heating coil 2 is energized to perform induction heating until the slab S reaches the target temperature. In order to prevent the slab S from falling over, the first to fourth four slab upper surface support devices are used. Slab S using all 4 to 7
It is common to support the upper side of the vehicle.

After heating the slab S to the target temperature, the first
While the upper surface of the slab S is supported by the fourth slab upper surface support devices 4 to 7, the elevating furnace hearth 3 is lowered until the upper surface of the slab S reaches the lower position of the side wall 1c. At the time when it is extracted and transferred to a turning device (not shown).
Then, the fourth to fourth slab upper surface support devices 4 to 7 are raised to the standby position. Thereafter, the width direction of the slab S is returned to a horizontal direction by a turning device, and then the slab S is transported to a rolling line and rolled.

[0006]

However, according to the above-described conventional method, the portions of the first to fourth slab upper surface support devices 4 to 7 where the metal fittings 4b to 7b come into contact with the slab S are the heat of the slab S. Moves from the metal fittings 4b to 7b to the cooling water, so that a local temperature drop occurs in comparison with other side portions where the metal fittings 4b to 7b do not come into contact, and the quality of the rolled product due to the temperature drop is generated. There was a problem above.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has a method and an apparatus for supporting a slab in a rigid induction heating furnace in which a local temperature drop on a slab side is reduced. The purpose is to provide.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a slab having a rigid width direction is placed on an elevating hearth which can be raised and lowered, and a plurality of slab upper surface supporting devices are used to mount the upper surface of the slab. A method for supporting a slab in a rigid induction heating furnace in which a slab is heated by an induction heating coil arranged on a side wall of a furnace body in a state where the slab is supported from above in a longitudinal direction, wherein the slab upper surface supporting device is provided one by one or in a plurality. A method for supporting a slab in a rigid induction heating furnace, characterized in that the ascending and descending steps are alternately repeated to support the upper surface of the slab.

[0009] The present invention also provides a lifting hearth which is placed vertically on a slab having a rigid width direction and which is vertically movable, and a plurality of slabs which support the longitudinal direction of the upper surface of the slab from above. A slab support device in a rigid induction heating furnace comprising an upper surface support device and an induction heating coil disposed on a side wall of the furnace body to heat the slab, wherein a tip metal of the slab upper surface support device contacts an upper side surface of the slab. Operation cycle setting device for setting the time to be performed and the operation sequence thereof, and slab upper surface support device operation for sequentially and alternately controlling the elevation of the slab upper surface support device one by one or a plurality of units based on a command signal of the operation cycle setting device A slab support device in a rigid induction heating furnace comprising a control device.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic diagram showing a partial cross section of an embodiment of the present invention, and FIG. 2 is a diagram illustrating an operation state of a slab upper surface support device. In the figure, the same members as those of the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 1, reference numeral 10 denotes a slab upper surface support device operation control device, and 11 denotes an operation cycle setting device. Slab upper surface support device operation control device 10 is an operation cycle setting device
Based on the command signal from 11, the first to fourth slab upper surface support devices 4 to 7 are sequentially controlled to move up and down to support the slab S. In addition, as the first to fourth slab upper surface support devices 4 to 7, a conventional air cylinder is changed to, for example, a hydraulic cylinder having a large power so that even one slab S can be reliably supported.

Therefore, based on a command signal from the operation cycle setting device 11, the slab upper surface support device operation control device 10 of the present invention, as shown in FIG. The device 5 → the third slab upper surface support device 6 → the fourth slab upper surface support device 7 are sequentially raised and lowered one by one, and the upper surfaces of the slab S are brought into contact with and supported by the tips 4b to 7b for a predetermined time. . In this case, as illustrated in FIG. 3, but in each slab upper surface supporting device is brought into contact by a certain time t _S, the slab S
It is preferable to wrap so as to make contact at the same time only for the time of Δt in order to prevent the falling down.

As described above, while the slab S is being heated, the upper surface of the slab S is supported by periodically raising and lowering the plurality of slab upper surface supporting devices one by one. The contact time with one slab S can be reduced to, for example, １ ／, and a local decrease in temperature of the slab S can be prevented to achieve uniform heating. At the time of loading and extracting the slab S, the slab may fall down. Therefore, the slab S should be firmly supported and stabilized using all the first to fourth slab upper surface support devices 4 to 7. I do.

If the slab cannot be supported by one unit due to the capability of the upper surface supporting device, the same effect can be obtained by devising a cycle by alternately raising and lowering the slab by a plurality of units.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS When a steel slab S having dimensions of width: 1000 mm × thickness: 220 m × length: 10,000 mm is heated by using a rigid induction heating furnace, the slab upper surface support of the present invention shown in FIG. 1 is heated. The device operation control device 10 was used. At this time, the operation cycle setting device
11, time t _S ; 10 min, Δt; 1 min are set, and the four first slab upper surface support devices 4, the second slab upper surface support device 5, the third slab upper surface support device 6, and the fourth slab upper surface support device 7 are set. Were controlled via the slab upper surface support device operation controller 10 respectively.

As a result, as shown in FIG.
The temperature decrease at the positions b to 7b is caused by the target heating temperature T _S ;
00 in the prior art for the ° C. T _S; what was 24 ° C. is, in the present invention examples it can be seen that as small as 11.5 ° C. and less than 1/2.

[0017]

As described above, according to the present invention,
Since the upper surface of the slab is supported by repeating the ascending and descending of the plurality of slab upper surface supporting devices one by one or a plurality of units in turn, the contact time is at least inversely proportional to the number of the slab upper surface supporting devices. The size can be reduced to suppress a decrease in the temperature of the slab, thereby preventing poor quality of the rolled product. Also, there is an effect that the life of the tip metal can be extended.

[Brief description of the drawings]

FIG. 1 is a schematic diagram partially showing a cross section of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation state of the slab upper surface support device according to the present invention.

FIG. 3 is an explanatory diagram showing an example of the operation of the slab upper surface support device.

FIG. 4 is a characteristic diagram showing the effect of the present invention.

FIG. 5 is a side sectional view showing a conventional example of a rigid induction heating furnace.

FIG. 6 is a sectional view taken along the line AA of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Furnace body 1a Side wall 1b Ceiling 1c Side wall 2 Induction heating coil 3 Elevating hearth 4 First slab upper surface support device 4a Piston rod 4b Tip hardware 5 Second slab upper surface support device 5a Piston rod 5b Tip hardware 6 Third slab upper surface support device 6a Piston rod 6b Tip hardware 7 Fourth slab upper surface support device 7 7a Piston rod 7b Tip hardware 10 Slab upper surface support device operation control device 11 Operation cycle setting device S Slab

Claims (2)

[Claims] 1. A state in which a slab having a rigid width direction is placed on an elevating hearth that can be raised and lowered, and the longitudinal direction of the upper side surface of the slab is supported from above by using a plurality of slab upper surface support devices. A slab support method in a rigid induction heating furnace that heats a slab with an induction heating coil disposed on a side wall of a furnace body, wherein the slab upper surface support device is sequentially raised and lowered one by one or a plurality of units at a time. A slab support method in a rigid induction heating furnace, wherein the method is repeated to support the upper surface of the slab. 2. An elevating hearth, on which a slab having a rigid width direction is placed and which can be raised and lowered in the vertical direction, and a plurality of slab upper surface supporting devices for supporting a longitudinal direction of an upper side surface of the slab from above. A slab support device in a rigid induction heating furnace comprising: an induction heating coil that heats a slab disposed on a side wall of a furnace body, wherein a time at which a metal tip of the slab upper surface support device contacts an upper side surface of the slab and An operation cycle setting device for setting an operation order, and a slab upper surface support device operation controller for sequentially and alternately controlling the slab upper surface support device one by one or a plurality of units based on a command signal of the operation cycle setting device. A slab support device for a rigid induction heating furnace, comprising: