SU971566A2 - Method for automatically controlling secondary cooling of ingot in continuous metal casting machine - Google Patents

Description

The invention relates to the continuous casting of metals by injection of molten mass, by casting into tubular casting molds with open ends, and can be used in automatic control systems for secondary cooling of the ingot in the continuous casting of metal.

Lime N is a method of automatically controlling the secondary cooling of an ingot on a continuous metal casting machine according to ed. St. No. 593813, which means that when asymmetry of the heat sink from the ingot faces occurs in the mold, the indicated heat sink asymmetry is compensated by proportional redistribution of water along the ingot faces in the secondary cooling zone in accordance with the law

i

4nV + К.2, „(1Зс.

i 1,2,3,4, n 1, 2 ... Ill,

cooling water flow rate

where the i-th face in the n-th section of the secondary cooling zone;

V- speed of gearing;

 specified (calculated) heat sink from the i-th wall of the mold; Q - flow heat from I

mold walls; K, K2p - proportionality coefficients for the n-th section of the zone

secondary cooling; m is the number of sections of the secondary cooling zone.

The disadvantage of this method is that this method does not allow to evaluate and then get rid of

“5 from the asymmetry of the heat sink from the faces of the ingot that occurs directly in the secondary cooling zone. Meanwhile, such an asymmetry occurs quite often due to various kinds of disturbances in the operation of the nozzles of any face of this section, due to the violation of the geometric symmetry of the axis of the ingot relative to the axis of the machine, etc.

Claims (1)

The result of this asymmetry of the heat sink is the irregularity of the temperature field around the perimeter of this cross section of the continuous ingot in the section in question, which inevitably leads to deterioration of its internal structure and ultimately to a decrease in the yield of suitable metal from the machine. Repeatedly attempted attempts to use optical pyrometers, sighted on the verge of an ingot in this section, to assess the asymmetry of the heat sink in separate sections did not lead to success for a number of reasons. Firstly, it is structurally very difficult to place a group (at least four) pyrometers in one section of the machine. In addition, optical pyrometers are sighted on a relatively small portion of the surface of the continuous ingot, which does not allow one to estimate the nature and amount of heat removal from the face of the ingot as a whole in this section. The aim of the invention is to increase the yield of metal from the machine. The goal is achieved by the fact that the famous author. St. No. 593813, the method introduces a measurement of the temperature difference and the amount of water cooling the rollers in one section at the output from each section of the secondary cooling zone, calculates the product of these quantities, which determines the heat dissipation of each roller of this section, compares it with the corresponding heat sink calculated for this roller a symmetrical temperature field over the cross section of the ingot, and change the water supply to the rollers of this cross section until the heat removal of each roller of this cross section becomes equal to the calculated heat sink. A variant of the device that implements the method in question is shown in the drawing. The device is considered in relation to the wide facets of the ingot in this section, as applied to the narrow facets in the same section, it is quite similar. The device contains resistance thermometers 1 on the inlet and outlet cooling water pipes to the rollers of this section, differential normalizing converter 2, to the input of which thermometers are connected, sensor 3 for cooling water flow through the roller, block 4, to the first input of which the differential output is connected normalizing converter 2, and to the second input - sensor 3 of cooling water flow through the roller, unit 5 of a given amount of water; black roller and regulator 6, to the first input of which the unit is connected 4 multiplications, and the second - the setting device 5, the output of the regulator 6 is connected to the valve 7, which changes the flow of cooling water to the roller. The device works as follows. When the heat sink of this roller deviates from the set value, which is detected by the resistance thermometer 1 and the differential normalizing transducer 2, as well as by the sensor 3, the signal level at the output of the multiplication unit 4 changes and as a result of comparison with the reference signal from the setpoint 5 it passes to the regulator 6. The regulator 6, acting on the water supply valve 7 to the roller, changes the amount of water supplied and thereby restores the calculated value of the heat sink with this roller from the corresponding face of the continuous ingot. The use of the invention allows to improve the internal structure of the continuous ingot and to increase the yield of metal from the machine by 0.1-0.2%. The application of the proposed invention in the continuous casting of steel with a capacity of 3.5 million tons will provide an economic effect of about 80.0 thousand rubles per year. The invention The method of automatic control of the secondary cooling of the slItka on the machine for continuous casting of metal according to ed. St. No. 593813, characterized in that, in order to increase the yield of the metal /, the temperature of the differential and the amount of water cooling the rollers in one section at the exit of each section of the secondary cooling zone are additionally measured, the product of these quantities determining the heat dissipation of each roller sections, compare it with the heat sink calculated for a given roller, corresponding to a symmetrical temperature field over the ingot section, and in case of a mismatch, the water supply to the rollers of this section is changed to eliminate this go mismatch. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 593813, cl. On 22/11/16, 1978.