JPS62170422A - Cooler for steel sheet - Google Patents

Abstract

PURPOSE:To make adjustment of cooling rates over a wide range possible by disposing plural headers for pipe laminars for weak cooling between headers for slit laminars for force cooling disposed in the transverse direction of a steel sheet. CONSTITUTION:The headers 3a-3c for slit laminars for strong cooling are disposed to intermediate pipings 2 branched from a water feed main pipe 1 via 3-way valves 8a-8c so as to face the steel sheet 10 in the transverse direction thereof. The headers 4a-4d for pipe laminars for weak cooling are disposed between said headers 3a-3c via 3-way valves 9a-9d so as to face the steel sheet 10 in the transverse direction thereof. The total number of only the headers 3a-3c for slit laminars are used when a high cooling rate is requested in such constitution. The total number of only the headers 4a-4d are used when a low cooling rate is required. The headers 3a-3c and 4a-4d are used in proper combinations when the intermediate cooling rate is requested.

Description

DETAILED DESCRIPTION OF THE INVENTION <Object of the Invention> Industrial Field of Application The present invention relates to a cooling device for steel sheets, and more particularly to a cooling device for steel sheets rolled in a hot rolling mill.

Conventional technology Conventionally, as a cooling device for steel plates after hot rolling in a steel plant, there are a pipe laminar shown in Fig. 4 and a slit laminar shown in Fig. 5. Pipe laminars usually have slits for low cooling. Laminar is used as a high cooling header.

There is no problem if any of the above-mentioned cooling capacities are sufficient for cooling the hot rolling line, but a problem arises when a variable cooling section from a low cooling capacity to a high cooling capacity is required.

There is a method of adjusting the amount of water as a means of variable cooling, but this takes time to adjust the amount of water and cannot keep up with the line speed of the hot rolling mill. In addition, there is a limit to the range of cooling capacity that can be achieved by varying the amount of water, making it impossible to secure a sufficient range of cold parts. Only a heat transfer coefficient of a3 is possible.

In addition, Japanese Patent Application Laid-Open No. 59-1 (I2231) proposes a cooling device in which vibraminers for strong cooling and weak cooling are redundantly arranged, but it is still not possible to secure a sufficient range of variable cooling capacity. .

Problems to be Solved by the Invention The present invention aims to solve these problems.Specifically, it is a method for cooling steel sheets that secures a wide range of cooling capacity and can sufficiently follow the rolling speed. The purpose is to provide equipment.

<Structure of the Invention> Means for Solving the Problems and Their Effects The present invention provides a cooling device for cooling a hot-rolled steel plate, in which a header of a slit laminar nozzle for intense cooling is installed across the plate width, facing the steel plate. Meanwhile, between the headers of the slit laminar nozzles, a plurality of headers each having a pipe lamina nozzle for weak cooling in the sheet width direction facing the steel plate are disposed, and the slit laminar nozzles and the pipe lamina nozzle The cold section speed can be adjusted over a wide range by injecting water through the nozzles individually or in combination.

That is, in the present invention, a header for a pipe laminar having a low cooling capacity is installed between headers for a slit laminar having a high cooling capacity, and the number of water injection headers is changed by switching a three-way valve, thereby making the cooling capacity variable. For example, a) If a high cooling rate is required, water is injected into all headers for Surin I and laminar.

口) If a low cooling rate is required, inject water only into all pipe laminar headers.

c) If an intermediate cooling rate is required, water is poured into a portion of the slit lamina and pipe lamina.

This allows the cooling rate to be varied over a wide range by combining water injection nozzles.

Hereinafter, the configuration and operation of the present invention will be explained using the drawings.

Fig. 1 is an explanatory diagram of an example of the arrangement of a group of cooling headers and a piping system of the present invention, Fig. 2 is a graph showing the relationship between water density 1 degree and heat transfer coefficient, and Fig. 3 is a diagram of the present invention. FIG. 4 is a graph showing the heat transfer coefficient obtained in the water injection lug combination of the invention, FIG. 4 is an explanatory diagram of a cooling device using a conventional vibrator, and FIG.
- It is an explanatory diagram of a cooling device using laminar.

In Figure 1, 1 is the main water supply pipe, 2 is the intermediate piping from the main water supply pipe to the header, 38 to 3C are headers for slit laminars, 3'a to 3'o are slit laminars, 48 to 4
d is the header for the pipe laminar, 4' a to 4' d is the vibrating laminar, 5 is the gate valve, G is the cylinder valve that turns on and off the water injection to the ladder for the slit laminar, 7 is the water injection to the ladder for the pipe laminar Cylinder valve to turn on/off, 8 is a three-way valve to select whether to inject water into the ladder for the slit laminar or drain it, 9 is to select whether to inject water to the ladder for the pipe laminar or drain it. It is a three-way valve.

The combination of headers for water injection is done by setting the three-way valve of each header to water injection or drainage.

For example, the operation will be explained in detail by taking case C2 in Table 1.

In FIG. 1, the slit laminar on-off valve 6 is opened by a command signal while the gate valve 5s of the intermediate pipe 2S branched from the common water supply main pipe 1 is kept open at all times, and the three-way valve 8b of the slit laminar is controlled by a command signal. The water supply side is opened by a signal, and the other three-way valves 8a and 8C are set to the drain side, and water is injected from the slit laminar only into the slit laminar three-way valve 8b. Similarly, the gate valve 5p of the intermediate pipe 2p for the pipe laminar is set at all times, the on/off valve 1 for the pipe laminar is opened by a command signal, and the three-way valves 9a, 9b, 9C19 of the pipe laminar are opened.
Of these, the on/off valves 9a and 9d are opened to the water supply side in response to a control command signal to inject water, and the other on/off valves 9b and 9C are opened to the drain side to drain water. In this way, as shown in FIG. 3, a heat transfer coefficient α2 is obtained, which corresponds to one slit lamina and two pipe laminas. Hereinafter, in the same manner, Case 04 to Case G,
Various heat transfer coefficients can be obtained by combining slit and pipe lamina.

Example Examples will be explained below.

The water injection headers are combined as shown in Table 1 by turning on (supplying water to the water injection side) and turning off (supplying water to the drainage side) the three-way valve 8.9. For example, the water density when water is poured into all headers of the slit laminar is set to 1, and the water density when water is poured into all headers of the pipe laminar is set to w2.

As in the case of C1, when only the pipe lamina (4a to 4d) is injected with water, the α value can be C1 as shown in FIG. This is the minimum cooling capacity for this equipment. C
As in case 4, all headers (3a~3C14a~4
d) The α value when water is poured can be α as shown in FIG. The cooling capacity is the maximum value of this equipment. C
As in case 2, the slit laminar I! (3b),
When the two pipe laminars (4a, 4d) are thinned out and water is injected, the α value can be C2 shown in FIG. As in the case of C3, when only the slit laminar is injected with water, the α value is
C3 shown in FIGS. 2 and 3 may be taken. In addition, by changing the combination of water injection headers other than the above,
It is possible to take various α values in the range from α to α.

In this way, the present invention makes it possible to set the cooling section capacity according to the required cooling section speed of the plate.

<Effects of the Invention> As explained above, the present invention provides a cooling device for cooling a hot-rolled steel plate, in which a header of a slit laminar nozzle for strong cooling is disposed in the width direction of the steel plate, facing the steel plate. On the other hand, between the headers of the slit laminar nozzles, a plurality of headers including pipe laminar nozzles for weak cooling are arranged in the width direction of the steel plate, facing the steel plate, and the slit laminar nozzles and the pipe laminar nozzles are each individually connected. A cooling device for a steel sheet, characterized in that the cooling rate can be adjusted over a wide range by injecting water in combination, and the present invention can obtain a wide range of cooling performance for hot rolled sheets. , and it is now possible to fully follow the line speed of the hot rolling mill.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of an example of the main arrangement and piping system of the cooling header of the present invention, Fig. 2 is a graph showing the relationship between water stone density and heat transfer coefficient, and Fig. 3 is a combination of the water injection header of the present invention. FIG. 4 is an explanatory diagram of a cooling device using a conventional pipe laminar, and FIG. 5 is an explanatory diagram of a cooling device using a conventional slit laminar. Code 1: Water supply main pipe 2: Intermediate piping 3a to 3C: Slit laminar header 3' a to 3' c: Slit laminar 4
a~4d・・・Pipe laminar header 4'
a~4' d...Pipe laminar 5...
・Manual gate valve 6...On-off valve (for slit laminar) 7・
...On-off valve (for pipe laminar) 8...
... Three-way valve (for slit laminar) 9 ... Three-way valve (for pipe laminar) 10 ... Steel plate

Claims (1)

[Claims] In a cooling device that cools a hot-rolled steel plate, a header of a slit laminar nozzle for intense cooling is arranged in the width direction of the plate facing the steel plate, and a header of a slit laminar nozzle facing the steel plate is disposed between the headers of the slit laminar nozzle. A plurality of headers equipped with pipe lamina nozzles for weak cooling are arranged in the width direction of the plate, and the cooling rate can be achieved over a wide range by injecting water through the slit lamina nozzles and the pipe lamina nozzles, either alone or in combination. A cooling device for a steel plate, characterized in that it is configured to be adjustable.