SU1729688A1 - Automatic control device for jet-type water-air cooling system of continuous billet casting machine - Google Patents

Abstract

The invention relates to metallurgy, more precisely to the continuous casting of billets, and is intended to automatically control the operation of a water-jet nozzle cooling machine for continuous casting of billets. The goal is to increase the reliability of control and reliability of the device. The invention allows automatic monitoring of the operation of the air-to-air spray cooling, which ensures the stability of the casting process, improving the quality of the cast metal and preventing breakouts of the ingot crust. When the nozzles in the section are clogged, the control valve will automatically open to provide a predetermined flow rate of the water / air mixture, while the signal from the sensor will increase in proportion to the opening of the control valve and when the signal from the multiplier is exceeded, the comparison unit will give a signal to turn on the light and sound alarms; 2 Il. cl

Description

The invention relates to metallurgy, namely to the continuous casting of metals, and can be used in automated process control systems for continuous casting machines (MNL 3).

The closest to the present invention is a device that implements a method for automatically monitoring the operation of the nozzle cooling of a continuous casting machine, containing a pressure sensor for the cooler, a signaling unit for each section of the cooling zone, a flow meter, a comparison unit, and also an additional comparison unit and for each the section of the cooling zone-sensor and the positioner of the control valve, circuit I, and the flow meter output of each section is connected to the sensor input of the corresponding control valve, the output of which is connected to the first input of the corresponding comparison unit, the second input of which is connected to the output of the position sensor of the regulating valve, the output of the comparison unit is connected to the first input of the AND circuit, the second inputs of all AND diagrams are connected to the output of the additional reference block, the inputs of which are connected to the sensor and a pressure unit, the output of each circuit AND is connected to the input of the memory unit, the output of which is connected to the alarm unit.

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wherein the pressure sensor is installed in the common coolant supply pipe to the cooling zone.

A disadvantage of the known device is that it does not allow to determine the clogging of the nozzles in air-cooling systems because air introduces additional resistance in the system when it is mixed with water in the immediate vicinity of the nozzles. In this case, in order to ensure the specified flow rate of water through the nozzles, it is necessary to additionally create water pressure in the system by opening the valve to overcome this resistance. Without taking into account this additional resistance created by air and dependent on its pressure, it is impossible to control the clogging of the nozzles in the air-water systems, since in this case the system will detect the clogging of the nozzles (i.e., additional resistance) when the nozzles are actually not clogged.

The purpose of the invention is to increase the reliability of control and reliability of the device for air-to-air cooling of a continuous casting machine.

The goal is achieved by the fact that the device for automatically controlling the operation of the nozzle-water-air cooling system of a continuous casting machine, containing, for each section of the cooling zone, a water flow control valve, a control valve position sensor, a flow meter, a control valve position adjuster, a comparison unit and an alarm unit, further comprises an air pressure sensor, an air pressure adjuster and for each section of the cooling zone a multiplier, with the output of the water flow meter each the section is connected to the inlet of the setpoint adjuster of the corresponding control valve, the output of which is connected to the first input of the corresponding multiplier, and the air pressure sensor is connected to the input of the pressure settingter, the output of which is connected to the second input of the corresponding multiplier, the output of which is connected to the first input of the corresponding comparison unit, the second input which is connected to the output of the position sensor of the control valve, and the output of the comparison unit of each section of the cooling zone is connected to the corresponding th input signal block.

As a result of the application of the proposed device, the quality of the cast metal is improved due to the improvement of its macrostructure by stabilizing the thermal

mode in the cooling zone, as a result of water-air cooling.

FIG. 1 shows a block diagram of an automatic operation control device.

water jet air cooling; continuous casting machine; in fig. 2 is a plot of the change in position of the control valve versus water flow and air pressure, plotted

0 based on experimental data at NLMK.

The proposed device for automatic control of the operation of a water-jet nozzle cooling caster contains,

5 for example, four cooling sections (I-IV). Lg of the mold 1, the ingot 2 enters the cooling zone, where it is supported and guided by means of the rollers 3 and is cooled by the cooling mixture 4,

0 sprayed from the nozzles 5. The cooling mixture enters the nozzles through a control valve 6 located on the main supply line 7 and through the general supply air line 8 to the zone

5 cooling.

FIG. 1, in addition to displaying the sensor 9 and the setting device 10 of the control valve, the flow meter 11, the comparison unit 12, the air pressure sensor 13,

0 set of which includes electric contact pressure gauge 14, air pressure setting device 15, multiplier 16 and alarm unit 17.

The device works as follows.

In the process of continuous casting with a flow meter 11 (a DM-type sensor paired with a diaphragm and a secondary device), the flow rate in the section is measured

0 cooling zones. A signal proportional to the flow of water enters the input of the motor setting device 10 of the control valve. In the simplest case, the flow characteristic of the control valve is described by the linear dependence of the type

NklG-kl Svod, (1),

where Ncl; is the nominal value of the control valve opening in the i-th section,%;

0 ki coefficient of proportionality, depending on the design of the regulatory body, k 10-20% h / m;

Code, 1 - water flow through the i-th section, m / h.

5 This relationship characterizes the normal operating conditions of the control valve without clogging the nozzles in the section and with a stable inlet water pressure to the cooling zone. The deviation of the position of the control valve from this

a larger value indicates that the nozzles are clogged in the section, and the larger the deviation value, the greater the percentage of clogged nozzles in the section.

The flow rate of the water-air mixture 4 in the section of the cooling zone can be varied by means of a regulating member containing a control valve 6, which can be electrically or pneumatically actuated.

When the control valve 6 is opened, the valve position sensor 9, for example, of the induction type, generates a signal proportional to the measured valve opening value, while at the same time the setpoint generator 10 generates a signal HCl, proportional to the valve opening set value. The target value is set depending on the measured flow rate water SvodKsodno according to the discharge characteristics of the valve (1)) with a coefficient of proportionality equal to 1,03-1,05 ki, i.e. 3-5% higher than the nominal value But ,.

The output of the setting device 10 is connected to the first input of the multiplier 16, the second input of which receives the signal ksosA from the setting pressure of air 15, proportional to the air pressure of the air. measured by the sensor 13 with the help of an electrocontact manometer 14, i.e.

Kvaz dRvozd).

The output of the multiplier 16 is connected to the first input of the comparator unit 12, the second input of which receives a signal from the sensor 9 position of the control valve 6. During normal operation of the nozzles, the signal from the sensor 9, proportional to the measured opening value of the valve, does not exceed the signal Ncl {b air NCL; from the multiplier 16 and the comparison unit 12 will generate a signal equal to O, which is fed to the input of the signaling unit 17 corresponding to this cooling section. When the nozzles in the section are clogged, the control valve will automatically open to provide a predetermined flow rate of the water / air mixture, and the signal from sensor 9 will increase in proportion to the opening of the control valve and when it exceeds the signal from

multiplier 16 comparison unit 12 will generate a signal equal to 1, which will turn on the light and sound alarms on the channel 17 corresponding to this section.

Resetting the block 17 can be carried out automatically at the beginning (end) of the casting, i.e. when turning on (off) the drive of the swing of the mold 1 or manually by the operator of the caster when turning on

devices using the Start button.

The device can be implemented on standard equipment, for example, the AKESR series.

The device provides automatic control of the operation of the spray water-air cooling in order to ensure the stability of the casting process, improve the quality of the cast metal and prevent breaks of the ingot crust.

Claims (1)

Invention Formula The device for automatic control of the operation of the water-jet nozzle cooling system. Continuous casting machines, containing for each cooling zone sections; a water flow control valve, a control valve position sensor, a flow meter, a control valve position adjuster, a comparator unit and an alarm unit, in that, in order to increase the reliability of control and reliability of the device, it additionally contains an air pressure sensor, an air pressure adjuster and for each cooling section, a multiplier, with the outlet of the water flow meter of each section being connected to the inlet of the setpoint adjuster of the corresponding control valve, the outlet of which is connected to ne vym entrance corresponding multiplier, and the air pressure sensor is connected to the input of the pressure setting device, the output of which is connected to the second input of the corresponding multiplier, the output of which is connected to the first input of the corresponding comparison unit, the second input of which is connected to the output of the position sensor of the control valve, and the output of the comparison section of each section of the cooling zone is connected to corresponding input of the alarm unit. OS / Z 2-S 5 5 4 -S FIG. 2