SU873481A1 - Device for regulating ore-melting furnace power - Google Patents

Description

(54) DEVICE FOR REGULATING THE POWER OF ORE-THERMAL OVEN

I

The invention relates to electro: thermia, and more specifically to the automatic regulation of the potential of a ore-smelting furnace with two electrodes in a single phase, for example, a six-electrode.

It is known a device — an automatic power regulator for APP-1 ore-smelting furnaces, comprising a phase current sensor, a useful voltage sensor, a block for determining the AC resistance, a comparison unit, a reference unit, a threshold element, a relay unit, an electrode displacement motor I

A disadvantage of this device is that when the electric mode deviates in phase, two electrodes are driven into motion, while it is advisable to move the electrode that is less buried in the charge.

It is also known to contain a current sensor in the control circuit of each electrode; phases and a useful voltage sensor associated with the input of the key unit, the output of which is connected to the input of the electrode displacement motor and a time relay whose output is connected to the first

the control input of the key unit, in which the depth of the electrodes in the charge is relative to each other, and is determined by probe movements of the electrodes according to the value of the ratio of the increment of the useful voltage to the increment of the current of phase 2.

A disadvantage of this device is that after trial displacements, the electrodes do not return to their original position. This leads to an error in determining the depth of the electrodes in the mixture, as well as to reduce the accuracy of power stabilization

15 phases.

The aim of the invention is to increase the number of economic indicators of the furnace operation by increasing the accuracy of stabilizing its power.

20

The goal is achieved by the fact that the device for controlling the power of the ore-smelting furnace is equipped with an electrode displacement sensor connected to the output of the pulse counting 2S input, the control input of which is connected to the time relay output and the output to the first input of the first comparison unit connected to the input the first task block,

30 and exit to the second manager

the input of the key block, to the first control input of the power supply unit, the output of which is connected to the engine input and the first control input of the switching unit, the output of the switching unit is connected to the first input of the comparison unit, the second input of which is connected to the output of the resistance unit, inputs which are connected to the outputs of current and voltage sensors, the output of the second comparator unit is connected via a threshold element and a relay unit to the key block, and through a null organ to the third control input of the key block, with the second control switch input of the switching unit and the first input of the coincidence unit, the second input of which is connected to the specified time relay output, and the output to the control input of the second phase electrode motor power supply unit, the outputs of the current and voltage sensors are connected to separate inputs of the detection unit COS C, connected with the output of the first and second keys, the output of the first key through the first one, the memory unit connected to the first input of the subtractor unit, the second input of which is connected to the output of the second key, its output through the second unit m ti. to the first input of the third comparison unit, the second input of which is connected with the output of the corresponding memory block of the second phase electrode, and the output of the fourth control input of the key block and with the identical input of the key block of the second phase electrode, the switching unit is connected to the second task block, first the control input with the control input of the second key, and the second input through the third memory block with the output of the third key, the input of which is connected to the output of the active resistance determination unit, and the control input to the control its input to the first key and to the output of the pulse generator connected to the second control input of the power supply unit and the output of the time relay, the control input of the relay being connected to the output of the null organ, and its output with the identical control input of the key block of the second electrode phase.

The drawing shows a block diagram of a device for controlling the power of a ore-smelting furnace.

The device contains a phase current sensor 1, a useful voltage sensor 2, a block 3 for determining the active resistance, 4-6 comparison units, a task block 7 and 8, a switching block 9, a threshold element 10, a relay block 11, motors 12 and 12 moving electrodes , time relay 13, electrode displacement sensor 14, pulse counter 15, pulse generator 16, power supply units 17 and 17, null organs 18 and 18, block 19 for determining the cosine of the phase shift between the phase current and the supply voltage, blocks 20-22 and 22 memories, key blocks 23 and 23 and keys 24-26, block 27 subtraction, block 28 matches

The device works as follows.

Q At the moment when the time relay 13 triggers, the signal from its output zeroes the pulse counter 15, enters the input of the pulse driver 16, to one of the inputs of the coincidence unit 28, locks the key

5, blocks 23 and 23. and, acting on power supply 17, supplies the motor 12 for moving the electrode to a nominal voltage. In this case, the output of the pulse generator 16 appears

0 pulse, which opens for a certain time the keys 24 and 26 to the signals from the output of block 3 to determine the active resistance and the output of block 19 to determine the cosine

5, the phase shift between the phase current and the supply voltage is fed to the inputs of the memory blocks 20 and 21, respectively. When the electrode moves, the signals from the pulse sensor 14 of the electrode electrode transfer 14 are fed to the input of the pulse counter 15. The signals from the output of the pulse counter 15 are fed to the first input of the comparison unit 5, the second input of which receives the signal

block 7 task. When moving

an electrode down by a specified amount at the output of the comparator unit 5, a signal appears that turns off the power unit 17, opens the key unit 23 and acts on the control

0 inputs of the switching unit 9 and the key 25. At the output of the subtraction unit 27, a signal is proportional to the increment of the cosine of the phase shift between the phase current and the supply voltage, which is fed to the input of the memory unit 22, and the signal is supplied to the input of the comparison unit 4 block 20 memory. The signal from the output of the unit 4 comparison is fed to the input threshold

Q element 10 and then from the output of the threshold element 10 to the input of the relay unit 11. From the output of the relay unit 11, a voltage flows to the input of the electrode moving motor 12,

causing the electrode to move in the opposite direction. At the moment when the value of active resistance of the phase becomes equal to the value at the moment of the beginning of the test movement, the signal

0 at the output of comparison block 4 is zero. This leads to the triggering of the null organ 18, which closes the key block 23, acts on the second control input of the switching unit 9 and enters the second input

block 28 match. In this case, the comparison unit 4 is supplied with a signal from the task unit 8, and the voltage of the second electrode of the control circuit of the second electrode is supplied from the power supply unit 17. At the end of a similar cycle, a signal appears on the output of the null organ 18 that triggers a time relay 13 to a new time cycle, and the output of memory block 22 produces a signal proportional to the increment of the cosine of the phase shift between the phase current and the power supply voltage Comparison unit 6 generates a signal of the corresponding polarity, which opens (closes) key block 23 and closes (opens) a similar key block 23 of the control circuit of the second electrode, if the value of the signal from memory block 22 is larger (less than the value of the signal from memory block 22 control of the second electrode. The application of the proposed device improves the accuracy of stabilization of the power of the furnace.

Claims (2)

1. Electric equipment and automation of electrothermal installations. Directory. Ed. A.P. Althausen et al., M., Energie, 1978, with. 226-267. 2. Authors certificate of the USSR on the issue No. 2678001,. cl. H 05 B 7/148, 1978.