JPS60124451A - Method for detecting and controlling abnormality of twin belt caster - Google Patents

Abstract

PURPOSE:To prevent an accident of a twin belt caster and to stabilize an operation by detecting electrically the oscillation of a dam block generated during casting and stopping pouring when a permissible value is exceeded. CONSTITUTION:A molten metal is poured from a ladle 1 via a tundish 4 into a caster 7 and at the same time the caster 7 is started to start casting. The base metal (a) penetrated into the clearance between dam blocks 8 forms a flash a' on the outlet side of the caster and is pulled in the drawing direction of a billet. The blocks 8 and a hoop 8-2 are pulled with said pulling and therefore the dam blocks in the lower part on the outlet side of the caster oscillate. The oscillation is transmitted via rollers 11-3 in sliding contact with the blocks 8 and levers 11-2 to differential transformers 11-4. The rate of oscillation is taken out of said transformers as a potential difference and is compared with a preset permissible value by a comparator 12. When the detected value exceeds the permissible value, a solenoid valve 14 is operated by a control device 13 to lower a cylinder 5, thereby stopping pouring to the caster 7. The sliding nozzle 2 of the ladle 1 is closed at the same instant to stop pouring to the tundish 4.

Description

[Detailed Description of the Invention] Technical Field of the Invention The present invention is a twin-belt caster developed for the purpose of improving the casting efficiency of cast slabs. Regarding detection and control methods.

Technical background of the invention and its problems The twin belt cask is 1. It consists of a pair of upper and lower endless belts and a pair of left and right dam blocks that are driven by being sandwiched between the belts, and casting is performed by supplying hot water between the endless belt and the dam blocks.

In this twin belt caster, the dam block that regulates the slab thickness has an expansion allowance, and at the beginning of rolling, this expansion allowance becomes a gap between the small blocks, creating gaps at one to several places. Therefore, when hot water is being supplied, molten metal is inserted into the gap. Also, when hot water is being supplied, the surface of the hot water may be disturbed or the water may be splashed, causing molten metal to reach the surface and bottom of the dam block. Insert. When this so-called hot water boils, the metal becomes flash on the exit side of the caster, causing the slab and dam block to pull together and damage the dam block.

For example, there are ways to prevent such accidents.
Japanese Patent No. 102244 proposes a method for preventing hot water from burning. In this method, a fixed dam is provided to cover the inner wall surface of the dam block on the short side of the dam block in the vicinity of the molten metal supply part of the mold and the solidification start part of the slab to prevent the pouring of hot water into the gap between the dam blocks. However, the thin part of the fixed dam may be deformed by heat, resulting in seizure, or the initially solidified shell on the short side may spread along the fixed dam in the casting direction, causing bulging to occur on the short side. This method has drawbacks such as unstable slab quality, and cannot be said to be a complete method for preventing hot water pouring. In addition, if a hot water jug is caused, it is necessary to detect this as soon as possible and decide whether or not to continue casting, but conventionally there is no way to detect the hot water as soon as possible. At present, we mostly rely on visual inspection.

Purpose of the Invention This invention was made in view of the conventional humorous sentiments mentioned above.
The purpose of this paper is to propose an abnormality detection and control method for twin belt casters that prevents damage to dam blocks by quickly and accurately detecting hot water and simultaneously stopping hot water supply, thereby ensuring safe and stable operation. It is something to do.

DISCLOSURE OF THE INVENTION The twin belt caster abnormality detection and control method according to the present invention electrically detects the vibration of the dam block that occurs during casting, compares the detected value with a preset value, and performs the detection. The feature is that when the temperature exceeds a permissible value, the water supply is stopped by tilting the tanditshu away from the casters.

By focusing on the phenomenon in which the dam block swings when it is pulled in the direction of , Arukumi is a method of automatically determining and controlling continuation.

An embodiment of the invention will be described below with reference to the drawings.

Figure 1 is a schematic diagram of the entire twin belt caster equipment.
(1) is a ladle, (2) is a sliding nozzle, (3)
is a sliding nozzle opening/closing cylinder, which is pivotally supported by a runner pedestal (6) (with a 41u tundish) and tiltably supported by a hydraulic cylinder (5).

(7) Hallein belt caster, (7-1) is upper heald, (7-2) is lower belt, (8) is dam block,
(8-1) is a small block, (8-2'l is a hoop (second
Figure) and (8-3) show the dam block guide roll.

(9) is a slab guide roll, (10 is a pinch row p).

Figure 2 shows an example of a device for carrying out the method of the present invention. (11) is a device that electrically detects abnormalities in the dam block, and the lever support rod (11-1) has a dam block attached to the tip. It consists of a lever (11-2) having a roller (11-3) in sliding contact with the dam block 8), and a differential transformer (11-4) that extracts the amount of swing of the dam block as a potential difference.

(12) is a comparator that compares the detected value with a preset allowable value and issues an abnormal signal when the detected value exceeds the allowable value; (5) This is a control device that operates the solenoid valve 04.

In the above device, the molten metal is first passed from the ladle (1) through the sliding nozzle (3) to the tundish (4).
By tilting the tundish (41) toward the caster (7) using the hydraulic cylinder (5), hot water supply is started.The molten metal poured into the tundish (4) is influenced by the tundish. Since the temperature is initially low, the hydraulic cylinder (5) is lowered and the tundish (4) is tilted away from the casters to drain some of the hot water before starting to supply hot water to the casters (7).

When the casters (7) are started at the same time as the start of hot water supply, the molten metal hardens inside the casters (7) and is guided by the guide rolls (9) on the exit side of the casters to form a pinch row/L.
/ Pulled out with a scream. During this casting process, for example, as shown in Figure 3, the ingot (
A) becomes a good burr (a) on the caster exit side and is pulled in the direction of pulling out the slab, and as a result, the dam block (8)
When the hoop (8-2) is pulled, the dam block at the bottom of the caster moves. On the other hand, if there is splash scattering during hot water supply, or overflow due to variations in the amount of hot water supplied, the lower and upper surfaces of the dam block
The molten metal is inserted into the upper bell) (7-1) and is rapidly cooled.
And it is guided to the caster exit side while being sandwiched between the lower belt (7-2) and the dam block (81), and the dam block swings 1d on the caster exit side as before, and the dam block (
8) and the lever (11-3) in sliding contact with the lever (
It is transmitted to the differential transformer (11-4)K via the differential transformer (11-2), the amount of fluctuation is taken out as a potential difference, and the value is compared with a preset tolerance value by a comparator (12), and the detected value is compared with the tolerance value. If it is contracted, fi!d, the comparator sends an abnormality signal to the control device θ (support), which operates the solenoid valve 04) to lower the tilting hydraulic cylinder (5). As the cylinder descends, the tundish (4) tilts toward the side opposite to the casters due to its own weight, so that the supply s to the casters (7) stops. At the same time, the sliding nozzle (2) of the ladle (1) is closed by operating the opening/closing cylinder (3), and the injection into the dandy dish (4) is also stopped.

Table 2 shows the results of the casting operation using the equipment described in Table 1 under the operating conditions shown in Table 1, in comparison with the conventional method in which abnormalities in the dam block were visually detected.

(Left below) As is clear from Table 2, abnormalities in the Kano dam block were detected three times during operation using this invented method, but we were able to respond quickly and prevent accidents.

As explained above, according to the present invention, it is possible to determine whether or not to continue casting by detecting the abnormal movement angle of the dam block caused by pouring hot water into the dam block. This will help prevent caster accidents and stabilize operations.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the overall equipment of a twin belt caster, Fig. 2 is an explanatory diagram showing an example of a device for carrying out the method of this invention, and Fig. 3 is a schematic diagram showing an example of a device for carrying out the method of this invention. FIG. 1...Ladle, 2...Sliding nozzle, 4
... Tanditshu, 5... Hydraulic cylinder,
6... Trunnion pedestal, 7... Twin belt caster, 8... Dam block, 11... Abnormality detection device, 11-1... Lever support rod, 11-2...・
...Lever, 11-3...Roller, 11-4...
- Differential transformer, 12... Comparator, 13... Control device, 14... Solenoid valve. Applicant: Sumitomo Metal Industries, Ltd. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In twin belt casters, which consist of a pair of upper and lower endless belts and a pair of left and right dam blocks that are driven by being sandwiched between the belts, the swinging of the dam blocks that occurs during casting is electrically detected and The detected value is compared with a preset tolerance value, and if the detected value exceeds the tolerance value, A is notified.
A method for detecting and controlling an abnormality in a twin belt caster, characterized by stopping hot water supply by tilting the L caster in the opposite direction.