JPH0890045A - Cooling method of rolled material - Google Patents

Abstract

PURPOSE: To execute flexible cooling suitable for respective rolled material by providing a cooler and heater in a cooling device and positively controlling the temp. of cooling water in the prescribed range, further to increase cooling capacity by lowering cooling water temp. so as to reduce cooling water quantity as well as pump load. CONSTITUTION: A cooling water cooler 3 and heater 4 are provided between a cooling water pit 1 and cooling header 2 of rolled material, these are connected by pipings 11, 15, 14 and 16, 10 respectively, flow meters 6b, 6c and ON/OFF valves 7b, 7c are arranged between these. Further, the system is constituted so that the load of a pump 5b is feeded back by the signal of flow meter 6c and the load of pump 5c by the signal of flow meter 6c. By this method, the temp. of cooling water in the cooling water pit 1 sprayed from the cooling header 4 is controlled to the prescribed range by the cooling water cooler 3 or heater 4, further cooling is executed while controlling a spraying water quantity as well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cooling a rolled material.

[0002]

2. Description of the Related Art Generally, when cooling a rolled material, the temperature of cooling water is not actively controlled, and when the cooling water temperature becomes higher than an allowable value, it is cooled using a cooling tower or the like. A method of controlling below the allowable value and JP-A-61-159
As in the inventions described in JP 27 and JP 61-15928 A, the temperature of the cooling water is stabilized by supplying make-up water into the water tank or replacing the cooling water in the water tank. It is known how to do it.

[0003]

However, the conventional method of simply controlling the cooling water temperature below the permissible value has no means for raising the cooling water temperature, so that the cooling water temperature is not maintained during winter or after repair work. When the temperature is lower than usual, there is a problem that predetermined controlled cooling cannot be performed unless a special method such as reducing the amount of water or shortening the cooling time is adopted.

Further, JP-A-61-15927 and JP-A-61-15927
As in the invention described in Japanese Patent No. 61-15928, in a method of stabilizing the temperature of cooling water by supplying makeup water into the water tank or replacing the cooling water in the water tank, the temperature control of the cooling water is performed. However, there is a problem in that the cooling capacity of the cooling device cannot be used efficiently because it is not actively performed. An object of the present invention is to positively control the temperature of the cooling water within a predetermined range, thereby making it possible to perform a predetermined controlled cooling that is suitable for each rolled material and can control the temperature of the cooling water. The purpose of the present invention is to provide a rolling material cooling method capable of increasing the cooling capacity of cooling water by lowering the cooling water, reducing the amount of cooling water and reducing the pump load.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to a rolling material cooling device for cooling a rolling material by injecting cooling water drawn from a cooling water pit from a header into a cooling water cooler and cooling water in the cooling device. When a rolled material is cooled by providing a heater, the temperature of the cooling water jetted from the header by the cooling water cooler or the cooling water heater is controlled within a predetermined range to cool the rolled material. The present invention is also a cooling method, and the present invention is a cooling device for a rolled material, which cools a rolled material by injecting cooling water pumped up from a cooling water pit from a header. When cooling the rolled material, the temperature of the cooling water jetted from the header is controlled within a predetermined range by the cooling water cooler or the cooling water heater, and the cooling water is cooled. The injection quantity of water is the cooling method of the rolled material, characterized in that to cool the control to the rolled material to a predetermined range.

[0006]

1 is a piping system diagram showing an example of the flow of cooling water in the rolled material cooling apparatus used in the present invention. In this case, a cooling water cooler 3 and a cooling water heater 4 are provided between the cooling water pit 1 and the rolled material cooling header 2. The cooling water cooler 3 is connected to the cooling water pit 1 through a pipe 11, and the cooling water cooling header 2 is connected to the pipe 1
5 and the pipe 10, and the pipe 15 is provided with a pump 5b, a flow meter 6b, and an on / off valve 7b from the cooling water cooler 3 side, and the load of the pump 5b is supplied by a signal from the flow meter 6b. Are configured to be feedback (FB) controlled.

Further, the cooling water heater 4 is provided in the cooling water pit 1.
Is connected to the cooling header 2 of the rolled material by a pipe 16 and a pipe 10, and the pipe 16 is connected to the cooling water heater 4 from a pump 5c, a flow meter 6c,
An on / off valve 7c is installed, and the load of the pump 5c can be feedback (FB) controlled by a signal from the flow meter 6c.

The cooling water pit 1 and the rolled material cooling header 2 are directly connected by a pipe 10, and the pipe 10 is connected to the cooling water pit 1 from a pump 5a and a flow meter 6
a, an on / off valve 7a is installed, and the load of the pump 5a is fed back (FB) by the signal of the flow meter 6a.
It is configured to be controllable. The cooling water supplied from the cooling water pit 1 to the cooling water cooler 3 through the pipe 11 is cooled to a predetermined temperature range by the cooling water cooler 3 and the flow meter 6b and the on / off valve on the outlet side of the pump 5b. 7
It flows through b and the pipe 15, and further reaches the cooling header 2 for the rolled material through the pipe 10 to cool the rolled material. At this time, the load of the pump 5b can be reduced by feeding back (FB) the flow rate of the flow meter 6b to the pump 5b as much as the cooling capacity of the cooling water is improved. Alternatively, instead of reducing the load on the pump 5b by the amount that the cooling capacity of the cooling water is improved,
It is also possible to reduce the load on the pump 5a and reduce the amount of water from the cooling water pit 1.

The cooling water supplied to the cooling water heater 4 shown in FIG. 1 may be supplied from the cooling water pit 1 through the pipe 12, or the high temperature water after cooling may be supplied to the pipe 14 and the pipe 13.
It is also possible to utilize the high temperature water after cooling and supplying the high temperature water. In addition, without providing the cooling water heater 4 and the cooling water cooler 3 specially, instead of the cooling water heater, steam, etc.,
Liquid nitrogen or the like may be used instead of the cooling water cooler.

According to the method of the present invention, extremely gentle cooling is performed using only the cooling water from the cooling water heater (normal temperature to 100 ° C), or the cooling water from the cooling water cooler (0 ° C to normal temperature). It is also possible to perform strong cooling using only. In particular, when the cooling water from the cooling water cooler is used, the cooling capacity per unit amount of water can be expanded, so that the load on the pump can be reduced by the amount corresponding to the improved cooling capacity, as described above. .

FIG. 2 is a piping system diagram showing another example of the flow of cooling water in the rolled material cooling apparatus used in the present invention. In this case, the cooling water pit 1 and the cooling water cooler 3
Is arranged so that the water cooled by the cooling water cooler 3 circulates in the cooling water pit 1 via the piping 11 and the piping 15. The inflow of the cooling water to the cooling water heater 4 may be supplied from the cooling water pit 1 through the pipe 12,
High-temperature water after cooling the rolled material may be supplied via the pipe 14 and the pipe 13. However, in any case, the cooling water heated by the cooling water heater 4 is connected to the cooling water pit 1 by the pipe 16
Returned via.

Further, the outlet pipes 10 and 1 of the cooling water pit 1, the cooling water cooler 3 and the cooling water heater 4, respectively.
Pumps 5a, 5b, 5c, flowmeters 6a, 6b, 6c, and on / off valves 7a, 7b, 7c are installed at 5 and 16, respectively, and the load of each pump is changed by the signal of each flowmeter. It is configured so that feedback (FB) control can be performed.

[0013]

EXAMPLE Using a cooling system for rolled material having the cooling water piping system shown in FIG. 3, 25 × 3500 × 24000 (m
The steel plate 17 of size m) was cooled. In this cooling device, a cooling water pit 1 and an upper nozzle 2 constituting the cooling device
a and the lower nozzle 2b are connected to the pipe 11d and the pipe 1 respectively.
1e was connected, the steam injection pipe 16 and the liquid nitrogen injection pipe 15 were connected to these pipes, and the temperature of the cooling water supplied to the upper nozzle 2a and the lower nozzle 2b was controlled.

The pipes 11d and 11e are provided with pumps 5d and 5e on the cooling water pit 1 side and a nozzle 2 respectively.
Water temperature meters 8a, 8b and flow meters 6d, 6e on the sides a, 2b
Was set up. The used cooling water is collected by the sluice 9 and returned to the cooling water pit 1 by the pipe 14. Upper and lower nozzle 2
As a result of injecting the steam 4a into the cooling water supplied to a and 2b to raise the cooling water temperature from the normal 35 ° C. to 50 ° C., the cooling rate at the minimum flow rate of the cooling device is as shown in FIG. It was possible to reduce the cooling capacity of the. This function can be advantageously used when performing extremely gentle cooling of a steel sheet.

Further, as a result of injecting liquid nitrogen 3a into the cooling water supplied to the upper and lower nozzles 2a, 2b to lower the cooling water temperature from the usual 35 ° C. to 20 ° C., the cooling rate at the maximum flow rate of the cooling device is increased. As shown in FIG. 5, it was possible to expand the cooling capacity of the cooling device. At this time, an equivalent cooling capacity can be obtained at a flow rate of about 80% as compared with the case where cooling is performed at a normal cooling water temperature of 35 ° C., and the cooling water supplied to the cooling device is reduced, and consequently the load of the water supply pump is reduced. It became possible to reduce.

[0016]

INDUSTRIAL APPLICABILITY The present invention is provided with a cooling water cooler and a cooling water heater to cool the rolled material and positively controls the temperature of the cooling water within a predetermined range. It is possible to perform a predetermined controlled cooling that can be controlled gradually, and to lower the temperature of the cooling water to increase the cooling capacity of the cooling water, reduce the amount of cooling water, and reduce the pump load.

[Brief description of drawings]

FIG. 1 is a piping system diagram showing a flow of cooling water in a cooling device used in the present invention.

FIG. 2 is another piping system diagram showing the flow of cooling water in the cooling device used in the present invention.

FIG. 3 is a piping system diagram showing a flow of cooling water in the cooling device used in the example of the present invention.

FIG. 4 is a graph showing the relationship between cooling water temperature and cooling rate.

FIG. 5 is a graph showing the relationship between cooling water temperature and cooling rate.

[Explanation of symbols]

 1 Cooling water pit 2 Cooling header for rolled material 2a Upper nozzle 2b Lower nozzle 3 Cooling water cooler 3a Liquid nitrogen 4 Cooling water heater 4a Steam 5 Pump 6 Flow meter 7 On / off valve 8 Water temperature meter 9 Thruth 10 Piping 11 Piping 12 Piping 12 Piping 13 piping 14 piping 15 piping 16 piping 17 steel plate FB feedback control signal

Claims (2)

[Claims] 1. In a rolling material cooling device for cooling rolled material by injecting cooling water pumped from a cooling water pit from a header, a cooling water cooler and a cooling water heater are provided in the cooling device to cool the rolled material. When cooling, the rolling material is cooled by controlling the temperature of the cooling water jetted from the header by the cooling water cooler or the cooling water heater within a predetermined range to cool the rolling material. 2. A rolling material cooling device for cooling a rolled material by injecting cooling water pumped from a cooling water pit from a header, wherein a cooling water cooler and a cooling water heater are provided in the cooling device. When cooling, the temperature of the cooling water sprayed from the header by the cooling water cooler or the cooling water heater is controlled within a predetermined range, and the amount of cooling water sprayed is controlled within a predetermined range to cool the rolled material. A method for cooling a rolled material, comprising: