JPS60102213A - Roll cooling water controlling device - Google Patents

Abstract

PURPOSE:To reduce the quantity of fresh water used by heightening pressure and quantity of discharge of roll cooling water to set values by a signal from a rolled material arrival detector, and lowering the pressure and quantity of discharge to minimum range of keeping cooling by a signal from a tail pass detector. CONSTITUTION:A cooling controlling device 13 gives a command signal to a voltage/frequency controlling device 13 to make the pressure of cooling water and quantity of discharge to set values according to an input signal 16 from the rolled material arival detector 12. Consequently, voltage or frequency is heightened, and an electric motor 10 is energized to raise the number of rotation of a booster pump, and maintains set values of water pressure and quantity of discharge. When a tail pass signal of a strip 2 is obtained from a tail pass detector, the cooling controlling device 13 lowers number of rotation of the booster pump after desired delay time through a voltage/frequency change controller 11 and the electric motor 10, and pressure or quantity of discharge of cooling water is lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a roll cooling water control device for a tandem rolling mill mainly used for hot rolling steel materials.

(Prior art) Since a large amount of cooling water is required to cool the rolls of a tandem rolling mill, there is a problem that not only does the electricity cost go down, but the temperature of the pressure-retained material also decreases by 1 degree Celsius. Cut 2 to 3 pieces of pressure water from LeQ water! In addition to installing equipment that allows easy access to water, or installing equipment that can separate and cool the water cooling system for each roll group as described in Japanese Patent Application Laid-Open No. 58-38603, The marrow that regulates the display / Kaisho 57-19071.0
The means described in the publication are used to rift and improve the roll cooling efficiency of rolled plate materials. Attempts are being made to prevent the decline in A'71M.

However, although the conventional technology has certain effects, the electricity cost is still high, and in particular, new rolling methods such as direct rolling with high reduction and high speed rolling can reduce electricity costs while preventing roughening of the roll surface. It was not possible to solve the problem.

(Object of the Invention) The present invention is a roll cooling water control device for a hot tandem rolling mill for steel materials, and is capable of properly cooling the rolls during rolling and non-rolling without affecting the roll consumption rate. It is clear that the system can significantly reduce the electricity consumption rate and reduce the amount of fresh water used.

(Structure and operation of the invention) FIG. 1 is a schematic explanatory diagram of an apparatus according to the present invention,
This figure shows a hot tandem finishing press machine (hereinafter referred to as finishing mill) consisting of six stands 1a to 1f. 2 is a material to be rolled during sheet threading (hereinafter referred to as "ztrip").

Cooling 1 water is passed from a cooling water supply source (not shown) through a cooling water main pipe 3, is pressurized to a predetermined pressure by an electric booster pump 4, is supplied to each branch pipe 6a to 6k through a distribution pipe 5, and is supplied to each of the branch pipes 6a to 6k. It is sprayed from a cooling nozzle 7b onto backup rolls 8a, 8b and work rolls 9a, 9b.

Reference numeral 10 denotes an electric motor whose rotation speed is freely controlled by a voltage/frequency conversion controller 11.

Reference numeral 12 is a rolling material arrival detector, such as a hot metal detector, and 13 is a cooling control device that operates in accordance with a cooling capacity control command 14 from a process calculation control device (not shown).

15a to 15f are rolling reaction force meters, and the pile pullout 1 of the rolled material 2
No. 6 can be easily determined by using all the signals from the reaction force gauges 15a to 15f.

That is, with the 100 input from the reaction force meter 15f, it is possible to directly estimate the horizontal direction, and with the other reaction force meters 15a to 15e, it is possible to estimate with high accuracy by adding the set time. Further, a stake detector (not shown) such as a hot metal detector may be provided on the exit side of the stand 1f.

Now, in the present invention, in response to the input signal 16 from the rolled material arrival detector 12, the cooling control device 13 controls the voltage/frequency control device 1 so that the cooling water pressure and discharge amount become the set values.
3 gives a combined signal. As a result, the voltage and/or frequency is increased and the electric BZO is energized and the rotational speed of the booster pump 4 is suddenly increased to increase water pressure and discharge, which has been confirmed to be able to increase the water pressure and discharge capacity of the booster pump 4. One set value is guaranteed.

Then, when the strip 2 is removed, a signal is obtained from the bottom removal detector, and after a desired delay time, the cooling controller 13 receives a signal from the voltage/frequency variable controller 11. The rotational speed of the booster pump 4 is lowered via the electric motor 10 mm to lower the water pressure and/or discharge amount of the cooling water.

In addition, by providing the cooling control device 13 with a function that allows the amount of roll cooling water to be changed according to the material and dimensions of the material to be rolled 2 during the passing of the material to be rolled 2 according to instructions from the higher-level process control device, the electric power consumption rate for cooling the rolls can be changed. can be further reduced.

The upper and lower limits of the water pressure and discharge amount can be determined in advance by searching for a cooling capacity that does not cause roughness or thermal cracking on the roll surface.

The inventor → presses a hole in the center of the axis of the work roll and arranges a compensating lead wire to heat the work roll in the range of 1.0 to 3 degrees below the roll surface.
By embedding a plurality of E pairs, changes in roll temperature during and after rolling were detected. As a result, 1.
The thermocouple buried at the fifth position approximates the roll surface temperature, and the detection results of the thermocouple confirmed that the roll surface temperature slowed to the lower limit 10 seconds after pile removal. From this fact, the water pressure of roll cooling water and/or discharge nLk
It has been confirmed that it is completely unavoidable to use slander, and it has been found that the lower limit can be easily set. Also, regarding the upper limit, the pressure υ and discharge amount at which the effect is almost saturated can be determined by increasing the same 11 degrees.

(Example) The control intermediate device of the present invention Nasu 4 was used for hot finishing rolling of a low carbon steel plate with a thickness of 20 mm on the entry side and a thickness of 1.8 mm on the exit side by hot finishing rolling (6 stand tandem), and the stand shown in Fig. 1 was used. l mill 1f
The roll cooling water pressure upper limit set value is f8Kg/rJ, the upper discharge rate upper limit value is 55tn3/'mIn, the pressure upper limit set value is 4.5Kg/ct, and the discharge lower limit 'I [36fn3A
As a result of operating as nin, electricity costs were reduced by 50%.

(Effects of the invention) In Figure 2, the vertical axis shows the booster pump power consumption (kWH).
/TS) and plots the changes with year and month on the product axis.The graph shows that the basic unit has been reduced to just under 1/3 since month G, when the present invention was adopted and appropriate control values were obtained. It turns out that it is.

In addition, Figure 3 is a graph with freshwater consumption (m3/T.S) on the vertical axis and year and month on the horizontal axis, and it can be seen that the consumption consumption has decreased by about 40% since month G when the present invention was implemented. .

[Brief explanation of the drawing]

Figure I is a schematic block diagram of the device of the present invention, Figure 2 is a graph showing changes in booster pump electric power consumption (k.WH/T.S), and Figure 3 is a graph showing changes in freshwater consumption. be. 1...Hot tandem finishing rolling mill, 1a to 1f...
Stand, 2... Rolled material, 3... Cooling water main, 4...
...Electric booster pump, 5...Distribution pipe, 6a-6
k...Branch pipe, 7a-7h...Cooling nozzle, 8a, 8
b... Backup rolls 19a, 9b... Work rolls. DESCRIPTION OF SYMBOLS 10... Electric motor, 11... Voltage/frequency conversion controller, 12... Unrolled material arrival detector, 13... Cooling control device, 15a-15f... Rolling reaction force meter. Representative patent attorney Masamitsu Akizawa and 2 others

Claims (1)

[Claims] (1) In a roll cooling water control device for hot tandem rolling, a rolled material arrival detector provided on the input side of the voltage machine; and a rolled material provided on the rolling mill or the exit side of the rolling mill. An electric booster pump for supplying cooling water whose rotation speed is freely controlled via a voltage/frequency conversion controller; The pressure of the roll cooling water is determined by the input signal of the rolled material arrival detector. and/or input a command signal to increase the discharge amount to a set value to the voltage/frequency control device, and set the pressure and/or discharge both to the minimum cooling level by receiving a bottom-off signal of the rolled material from the bottom-off detector. The command signal that lowers the voltage to the range that maintains the
A roll cooling water control device comprising: a cooling control device for supplying a frequency control device;