KR940010768B1 - Control method of shaft furnace pressure - Google Patents

Abstract

After controlling the pressure of a lower hopper (5) to the first set pressure (P1) by opening the gas recovery valve (12) in accordance with the material charging start signal of a detector (15) detecting the material level in blast furnace, the remaining gas of the lower hopper (5) is drawn out to open the injector dry valve (14) to be easily recovered. Then, when the pressure of the lower hopper (5) reaches the second set pressure (P2), the excess gas is drawn out in to the open atmosphere through the valve of the lower chamber (7) and first and second uniform pressure valves (9,10) to close the gas recovery valve (12) and open the pressure exhaust valve (11). A flow of the charge material from the upper hopper (2) to the lower hopper (5) is smoothed.

Description

Blast furnace back pressure method

1 is a schematic diagram of a blast furnace charging device.

2 is a hardware diagram for implementing the present invention.

3 is a control time schedule table of the pressure relief mode.

4 is a control time schedule table of the gas recovery mode.

5 is a control time schedule table of the pressure release and gas recovery mode according to the present invention.

* Explanation of symbols for main parts of the drawings

1: charging belt conveyor 2: upper hopper

3: upper hopper gate 4: upper chamber valve

5: Lower Hopper 6: Raw Material Control Gate

7: lower chamber valve 8: turning chute

9: 1st equalization valve 10: 2nd equalization valve

11 pressure relief valve 12 gas recovery valve

13: dust discharge valve 14: ejector drive valve

15: material level detector 20: mode selector

21: pressure release and gas recovery control mode time schedule setting unit

22: gas recovery control mode time schedule setting unit

23: pressure release control mode time schedule setting unit 24: automatic control command table storage unit

25: dump schedule setting unit 26: comparison unit

27: first counter 28: second counter

29: automatic operation control output unit

The present invention relates to a blast furnace top pressure backing method for application to a blast furnace plant top charging device.

In general, the high pressure operation (2.3kg / cm ² ) blast furnace charging device continuously monitors the raw material level according to the operating conditions in the furnace and operates a timer circuit that counts for a certain time when the raw material falls below the charging start level. -The sequential control of the pressure equalizing pump puts raw materials (iron ore / coke) into the blast furnace.

This blast furnace charging is carried out since the raw material loaded on the charging belt conveyor 1 of FIG. 1 is stored in the upper hopper (2). First, as shown in FIG. 1, when the raw material level detector 15 detects the raw material level in the furnace and generates a charge start signal, the dump timer counter starts to lift the raw material level detector 15.

Subsequently, when the swing chute 8 is rotated, the lower chamber valve 7 is opened, and the raw material control gate 6 is opened, the pressure of the lower hopper 5 is equalized to the pressure in the blast furnace, so the lower hopper The raw material of (5) is dumped in a blast furnace.

After the completion of the raw material dump is detected by the load cell (not shown) of the lower hopper 5, the raw material control gate (6), the lower chamber valve (7)-the turning chute (8) in the reverse order and the reverse order And stop and down the raw material level detector 15 to monitor the raw material level in the furnace to end the dump schedule.

Next, when the raw material of the upper hopper 2 is to be imported into the lower hopper 5, the pressure of the lower hopper 5 should be backed up equally to the pressure (atmospheric pressure) of the upper hopper 2.

To this end, the import timer allows the starting material to count start when the raw material on the charging belt conveyor 1 passes through the top start point with the lower seal valve 7 closed.

In addition, in the gas recovery mode, as shown in FIG. 4, the pressure of the lower hopper 5 is opened by opening the gas recovery valve 12 and the ejector drive valve 14 according to the time schedule of the gas recovery control mode. After back pressure from ² to 1000 mmAq or less, the gas recovery valve 12 and the ejector drive valve 14 are closed, and the upper chamber valve 4 and the upper hopper gate 3 are opened to determine the raw material of the upper hopper 2. Allow to discharge to lower hopper 5 in time. Accordingly, when raw material filling is sensed by the load cell of the lower hopper 5, the upper hopper gate 3 and the upper chamber valve 4 are closed to complete the back pressure and the import schedule.

Subsequently, the equalization schedule is filled with ² kg / cm ² of semi-clean gas by the primary equalization valve 9, and the secondary pressure equalizing valve 10 is opened to provide nitrogen pressure of about 4 kg / cm ² . Automatically controlled to equal pressure As a result, the pressure of the lower hopper 5 becomes equal to the internal pressure of the furnace, waiting for the next dump control.

In the back pressure mode of the charging control schedule, when the furnace pressure is 0.5 kg / cm ² or less in low pressure operation, it operates according to the above schedule and dissipates the pressure of the lower hopper 5 to the atmosphere, but it is not used during normal operation. Therefore, if gas leakage occurs in the lower chamber valve (7) and the first and second equalization valves (9, 10) during the mixing operation during normal operation, the pressure in the lower hopper (5) is increased after back pressure, and the upper hopper (2) Since a problem occurs in the flow of raw materials imported into the lower hopper 5, a problem occurs that an automatic operation error occurs due to insufficient raw material import within a predetermined time.

The present invention is to prevent the phenomenon that the productivity decreases according to the delay of the raw material import time to the lower hopper due to the rise in the pressure of the lower hopper according to the gas liquid in the back pressure mode of the conventional roadman equipment, pressure release during back pressure And it is an object of the present invention to provide a blast furnace back pressure method that can maintain the flow of the raw material smoothly through the mixed control of the gas recovery valve.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

2 is a hardware configuration diagram for implementing the present invention, wherein the automatic control command table storage section 24 includes setting data of the time schedule setting section 21-23 of the pressure release and / or gas recovery control mode. And configured to be selectively output by the switch (SW1) of (20), the automatic control command table storage unit 24 receives the data output of the dump schedule setting unit 25 to process the stored data to compare the comparison unit 26 The comparator 26 compares the schedule time outputs of the first and second counters 27 and 28 with the schedule output data of the automatic control command table storage unit 24 and outputs the automatic operation control output unit 29. The automatic operation control output unit 29 is configured to output signals for valve control of the top equipment according to whether the interlock unit 30 is controlled.

Therefore, the present invention can freely select three modes by pressure release and / or gas recovery according to the blast furnace operation conditions, and the dump schedule data (eg, as the time schedule of the selected mode is edited and stored as an automatic control command table). For example, it is possible to control the operation time of each valve through combination with blast furnace loading order, raw material designation, raw material control gate opening setting, turning chute rotation speed, and dumping timing for each raw material. Raw material

It is possible to prevent the import delay and the automatic operation error from this in advance.

This will be described according to the time schedule of FIGS. 1, 2 and 5 as follows.

First, when the raw material level detector 15 detects the raw material level in the blast furnace to generate a raw material loading start signal, that is, when the raw material import request signal is generated from the raw material level detector 15 for the lower hopper 5, the first counter As the number 27 is started, the gas recovery valve 12 is opened by the control output of the automatic operation control output unit 29 of FIG.

If the pressure of the lower hopper 5 is lowered below the first set pressure 4000mmAq (P ₁ ) by the opening of the gas recovery valve 12, it is detected automatically by the lower hopper pressure gauge (not shown). The control output unit 29 opens the ejector drive valve 14 to blow the instantaneous blast furnace pressure in the gas recovery direction so as to easily recover the gas in the lower hopper 5 so that the remaining pressure is completely backed up.

When the pressure of the lower hopper 5 is below the second set pressure 1000mmAq (P ₂ ) by the pressure gauge detects the pressure relief valve 11 containing the gas recovery valve 12 and dissipates the pressure of the lower hopper into the atmosphere Open. At this time, the ejector drive valve 14 is completely closed when the pressure relief valve 11 is fully opened.

At this time, the pressure relief valve 11 is open, so that the gas pressure leaking from the lower chamber valve 7 and the first and second equalization valves 9 and 10 is released into the atmosphere, so that the upper hopper 2 to the lower hopper 5 It ensures that the import of raw materials occurs within a certain time without interrupting the flow of raw materials to the furnace.

On the other hand, when the full load signal of the raw material is generated by the load cell of the lower hopper 5, the automatic operation control output unit 29 causes the upper hopper gate 3 to be closed, and the pressure relief valve ( 11) is also closed to complete the process from back pressure to import.

Subsequently, in the equalization mode, the primary equalization valve 9 is opened after closing the upper chamber valve 4 to form a primary equalization pressure (2 kg / cm ² ) using a semi-clean gas, and then closed. 10) is opened after closing the first equalization valve (10) and waits until the next dump start time.

This time schedule is designated by the automatic control command table storage unit 24 of FIG. 2 and counted by the start signal of the second counter 28, i.e., a signal generated at or below the raw material charging start level. When the operation condition is satisfied by comparing the data of the storage unit 24 with the count data of the second counter 28 in the comparator 26, the automatic operation control output unit 9 outputs control signals sequentially to each valve and gate. Therefore, the dump-back pressure-import-balance pressure-dump process is repeated.

Therefore, the present invention dissipates the gas leakage pressure appearing in the lower chamber valve and the 1st and 2nd pressure equalizing valve to the atmosphere during the back pressure of the lower hopper for importing raw materials to the blast furnace top equipment to maintain the pressure of the lower hopper at the same level as the atmospheric pressure. By doing so, flow disturbance at the time of raw material loading can be avoided, so that normal operation can be maintained without interruption of operation depending on the import of raw materials, thereby increasing productivity.

Claims (1)

In the back pressure mode for the raw material import of the blast furnace top charging facility, the gas recovery valve 12 is opened in accordance with the raw material loading start signal of the raw material level detector 15 for detecting the raw material level in the blast furnace, so that the pressure of the lower hopper 5 Back pressure to the first set pressure (P ₁ ) and then open the ejector drive valve 14 to further back the remaining pressure to facilitate gas recovery of the lower hopper 5, the pressure of the lower hopper (5) When the pressure reaches the set pressure P ₂ , the gas recovery valve 12 is closed and the pressure relief valve 11 is opened to prevent the leakage gas pressure caused by the lower chamber valve 7 and the first and second equalization valves 9 and 10. Blast furnace back pressure method characterized in that to smooth the flow of the raw material imported from the upper hopper (2) to the lower hopper (5) by releasing to the atmosphere.