JPS63137513A - Control method for preventing over-cooling of tail end of steel plate - Google Patents

Abstract

PURPOSE:To cool a steel plate excellent in shape and quality even at its tail end by detecting the time when the tail end of the steel plate is attained to an outlet of a first cooling bank and stopping injections of the cooling water from jet nozzles. CONSTITUTION:When the steel plate 1 conveyed in the (a) direction by a steel plate conveyer 2 is attained to a position shown by a solid line, the top end part of the steel plate 1 is detected by a steel plate detector 12. Then, based on its signal, a steel plate tracking device 14 is operated to feed the cooling water to the first - forth cooling banks 4-7 and to start the cooling. And then, during the steel plate 1 is passed through the banks 4-7, the cooling water is fed from both sides of upper and lower sides to cool. Then, pulse signals from a pulse oscillator 13 is counted by the steel plate tracking device 14 to detect the position of the steel plate 1 and, at the time when the tail end of the steel plate 1 is attained to the outlet side of the first cooling band 4, the injections of the cooling water from the jet nozzles 8, 9 are stopped. Therefore, no cooling water is flowed out from the clearance between dewatering rolls 10 and 11 to over-cool the tail end part.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control method for preventing supercooling of the tail end of a steel plate in steel plate cooling equipment.

(Prior art) In steel plate cooling equipment, a plurality of cooling banks are provided in the steel plate conveying direction for supplying cooling water from above and below to the steel plate conveyed by a steel plate conveying device, and a first cooling bank on the upper side is provided with There is also a steel plate equipped with a pair of upper and lower nozzles that spray cooling water diagonally toward the exit side, and a pair of upper and lower drain rolls that remove the sprayed cooling water from the steel plate.

When cooling a steel plate with this type of equipment, conventionally, the supply of cooling water from each cooling bank is started before the tip of the steel plate reaches the entry side of the first cooling bank, and the tail end of the steel plate reaches the final point. By the time we arrived, the supply of cooling water to each cooling bank had been terminated all at once.

(Problem to be Solved by the Invention) Conventionally, when the tail end of the steel plate passes through the first cooling bank, the cooling water injected from the upper and lower jet nozzles passes through the gap between the pair of upper and lower water cutter rolls to the adjacent downstream side. The cooling water flows out to the second cooling bank, and this flowing cooling water hits the tail end of the steel plate located in the second cooling bank, non-uniformly supercooling the tail end of the steel plate.

As a result, the tail end of the steel plate obtained using this cooling control method was deformed in the vertical direction, and the strength of the material was uneven.

The present invention solves the above-mentioned problems of the conventional steel plate cooling control method, and enables cooling of a steel plate with good shape and quality at the tail end of the steel plate as well as at the tip, center, etc. The purpose is to make it possible to do so.

(Means for Solving the Problems) The present invention provides that even if the tail end of the steel plate 1 does not pass through all the cooling banks 4 to 7, it can be placed on the exit side of the first cooling bank 4 with jet nozzles 8.9. It is detected that the cooling water has reached this point, and the cooling water injection from the jet nozzle 8.9 is stopped due to this ejection.
This prevents the tail end of the rope plate 1 from being overcooled.

(Example) Hereinafter, the present invention will be described in detail based on the illustrated example. In the figure, 1 is a steel plate, and 2 is a steel plate conveying device, which is composed of a roller table and the like, and is configured to be driven by an electric motor 3. Reference numerals 4 to 7 denote first to fourth cooling banks, which are arranged in series along the steel plate conveyance direction. The first cooling bank 4 has a steel plate l transported by the steel plate transport device 2.
35 towards the exit side of the first cooling bank 4.
A pair of upper and lower jet nozzles 8 and 9 that spray cooling water in an oblique direction at a spray angle of approximately
A pair of upper and lower draining rolls 10 and 11 are provided for removing the cooling water sprayed on both the upper and lower sides of the steel plate l.

The second to fourth cooling banks 5 to 7 are provided with an upper laminar and a lower spray so as to supply cooling water to both upper and lower sides of the steel plate 1. 12 is a rope plate detector, the first
The rope plate 1 is detected on the upper side of the cooling bank 4. Reference numeral 13 denotes a pulse oscillator, which generates a pulse signal in conjunction with the electric motor 3 of the steel sheet conveying device 2.

Reference numeral 14 denotes a steel plate tracking device, which supplies cooling water to each cooling bank 4 to 7 to start cooling when the steel plate detector 12 detects the tip of the steel plate 1, and a pulse oscillator 13
The position of the rope plate 1 is detected by counting the pulse signals from The injection of cooling water from the nozzles 8 and 9 is stopped, and when the rope plate 1 reaches the exit side of the fourth cooling bank 7 (dotted line position),
It is configured to stop the supply of cooling water to the second to fourth cooling banks 5 to 7.

In the cooling equipment configured as described above, when the steel plate 1 transported in the direction of arrow a by the steel plate conveying device 2 reaches the solid line position, the steel plate detector 12 detects the tip of the steel plate 1, and the steel plate tracking device 14 starts working. 1st to 4th cooling banks 4 to 7
Supply cooling water to start cooling. While the steel plate 1 passes through the first to fourth cooling banks 4 to 7, cooling water is supplied to the steel plate 1 from both upper and lower sides to cool it.

Incidentally, if the rope plate 1 has a thickness of 25mm, a width of 3000n, and a tentative length of 12m, the temperature at the entrance side of the first cooling bank 4 is 85mm.
When the temperature is 0° C. and the conveyance speed is 1.0 m/s, the amount of cooling water in the first to fourth cooling banks 4 to 7 is as shown in the table below. Note that the unit is rd/Hr.

In the first cooling bank 4, a pair of upper and lower jet nozzles 8, 9
The cooling water is injected obliquely toward the outlet side, and the cooling water adhering to the upper and lower surfaces of the steel plate 1 is removed by a pair of upper and lower drain rolls 10.11. Then, the position of the steel plate 1 is detected by counting pulse signals from the pulse oscillator 13 by the steel plate tracking device 14, and the tail end of the steel plate 1 is located on the exit side of the first cooling bank 4 as shown by the two-dot chain line. When this point is reached, the injection of cooling water from the jet nozzles 8 and 9 is stopped. Therefore, the cooling water injected from the jet nozzles 8 and 9 flows out from the gap between the pair of draining rolls 10.11 to the second cooling bank 5 side, hits the tail end of the rope plate 1, and passes through the tail end. There is no need to cool down.

When the steel plate 1 passes through the fourth cooling bank 7 and reaches the dotted line position, the steel plate tracking device 14 stops the supply of cooling water to the second to fourth cooling banks 5 to 7, and the cooling ends.

Through this series of cooling control methods, the steel plate 1 can be cooled until the temperature of the copper plate on the exit side of the fourth cooling bank 7 reaches approximately 500°C, and the flatness from the tip to the tail is good and the tensile strength is high. A steel plate 1 having a uniform material quality of 60 kff/mn can be obtained.

(Effects of the Invention) According to the present invention, the time point when the tail end of the rope plate 1 reaches the exit side of the first cooling bank 4 is detected, and upon this detection, the injection of cooling water from the jet nozzle 8.9 is stopped. In order to do so, rope v
The tail end of the steel plate i1 is not supercooled by the cooling water from the jet nozzle 8.9, and therefore, the steel plate tail end has a good shape and quality as well as the tip and center part. can be obtained.

[Brief explanation of the drawing]

The drawing is a configuration diagram of a steel plate cooling facility showing an embodiment of the present invention. l... Steel plate, 2... Steel plate conveyor, 4-7... Cooling puncture, 8.9... Jet nozzle, 10.11.
...Draining roll, 14... Steel plate tracking device.

Claims (1)

[Claims] (1) Cooling bank 4 that cools the steel plate 1 by supplying cooling water from above and below to the steel plate 1 conveyed by the steel plate conveying device 2.
7 in the steel plate conveying direction, and the first one on the upper side
The cooling bank 4 includes a first cooling bank 4 for the steel plate 1.
In a steel plate cooling equipment equipped with a pair of upper and lower jet nozzles 8 and 9 that inject cooling water diagonally toward the outlet side of the steel plate, the tail end of the steel plate 1 has reached the outlet side of the first cooling bank 4. A control method for preventing supercooling of a tail end of a steel plate, the method comprising detecting this and thereby stopping the injection of cooling water from jet nozzles 8 and 9.