KR940009664B1 - Automatic control method of inverse current - Google Patents

Abstract

The method prevents flowing backward caused by being clogged of tuyere at blast furnace facilities when processing the blowing-in of coal powder. The method employs: A) a flux sensor (11) detecting flux of ventilation in tuyere; B) electric control apparatuses (14,15,16) controlling blowing-in and stop of coal powder; C) a process computer (10) controlling the control apparatuses.

Description

Automatic control method for preventing backflow of blast furnace injection coal

1 is a schematic cross-sectional view of an apparatus for blowing pulverized coal into a blast furnace;

2 is a schematic block diagram of a conventional blast furnace blown coal backflow control system.

3 is a view illustrating a blow-off and blowhole purge process of a conventional blast furnace blown coal;

4 is a schematic block diagram of a pulverized coal backflow prevention automatic control system according to the present invention.

5 is an explanatory diagram of a process for purging tufts of pulverized coal and re-injecting pulverized coal for preventing pulverized coal backflow of the present invention.

* Explanation of symbols for main parts of the drawings

10 process computer 11 blower flow sensor

14 PLC (Programmable Logic Controller) 15: Relay

16: solenoid valve 17: control range set value input

18: uncontrolled wind vent selection input unit

The present invention relates to a method for preventing backflow (automatic control) according to blockage of wind holes during pulverized coal blowing operation in a blast furnace plant of an ironworks.

The pulverized coal used in the blast furnace plant of the steel mill is non-coking coal, and it is used directly in the blast furnace without going through the COKE process, thereby reducing the cost of molten iron production and suppressing the generation of inert zones under the blast furnace, which was a problem in the management of yellowing in the entire COKE operation. It is used for the purpose of improving the yellowing. Therefore, the blast furnace plant of the steel mill is equipped with a pulverized coal blowing facility to improve the operation and efficiency of the facility and at the same time strive to increase the pulverized coal blowing amount by developing the pulverized coal blowing operation technology.

The injection of pulverized coal into the blast furnace is carried out through the blow lance through the blow lance when the hot air is injected into the blast furnace by using 34 blast holes per blast circumferential direction to inject blast furnace made from the hot blast furnace into the blast furnace. Is committed.

1 is a schematic cross-sectional structure diagram of one of the 34 tuyere, the hot air of the blower pipe 21 through the tuyere 22 is provided on one side of the furnace wall 25 as referred to here When it is introduced into the (24), the pulverization is installed so that the pulverized coal supplied through the blowing lance 20 is sucked into the blast furnace.

At this time, wind tunnel clogging due to wind fall of the light bulbs and blast deposits (23) such as pulverized coal ash (ASH) according to the internal conditions of the blast furnace is often issued, resulting in the risk of downtime and large accidents.

The conventional system for blowing pulverized coal and stopping pulverized coal blowing / balloon purge shown in FIG. 2 uses a plurality of (34) blowhole flow rate sensors S ₁ to Sn provided in the circumferential direction of the blast furnace of FIG. Blowing flow rate sensor unit 11, a process computer 10 for processing the detection signal of the sensor unit to provide the monitor 12 so that the operator knows the blowing flow rate information, the blowing air that the operator knows from the monitor 12 The control command for inputting the operation command to the process computer 10 manually by continuously confirming the flow rate information based on the control command input unit 13, the control command manual input unit 13; The process computer 10 which receives the pulverized coal injection stop / purge start command sends a command to the electric control device 14, 15, 16 which executes the pulverized coal injection stop / pulverized coal injection stop / balloon purge start command. The electrical control device includes a PLC 14 for processing an electrical signal, an electrical signal relay 15 for processing an on / off contact signal, and a solenoid valve 16 for performing pulverized coal injection, pulverized coal injection stop, and blower purge of a corresponding tuyere. ). In the electric control apparatuses 14, 15, and 16, the PLC 14 is programmed to receive the operator's operation command from the process computer 10 and to operate or stop the solenoid valve. 15) turns on / off according to the command of the PLC 14 to control the solenoid valve of the corresponding tuyere.

The solenoid valve 6 is an S-way (unidirectional) solenoid valve which operates using air, and operates according to the on / off of the relay 15 according to the instruction of the PLC 14. If the relay 15 is in the ON state, the solenoid valve 16 is operated by the princess injection, and when the solenoid valve 16 is disposed at the correct position where the pulverized coal can be blown, by the PLC 14 As the relay 15 is turned off, the solenoid valve 16 is fixed in such a state that pulverized coal can be blown into the blown lance. In addition, the solenoid valve 16 can be fixed in a state capable of injecting nitrogen according to the above principle. As a result, the battery control device 14, 15, 16 according to the operator's operation command is selected from the pulverized coal or nitrogen in the blowhole blow lance 20 through the PLC 14, the relay 15 and the solenoid valve 16. It is configured to be supplied with.

Therefore, the blast furnace plant operator of the steel mill processes 34 pieces of blown flow rate information measured from the blower flow rate sensors S ₁ to Sn installed in the circumferential direction of the blast furnace in order to inject hot air into the blast furnace. And monitor continuously from monitor 12, and if any one of the 34 vents recognizes that the vent flow is continuously decreasing, the operator directly orders the pulverized coal blow-off and start of the vent. By inputting into the process computer 10, the electric control apparatuses 14, 15, and 16 which take in and pulverize pulverized coal are operated.

FIG. 3 is a schematic view of a flow chart according to the prior art of FIG. 2, in which each of the air blowing air flow rates is sensed from the blowing flow rate sensor 11 of FIG. 2 and transmitted to the monitor 12 through the process computer 10. FIG. Is sensed. Thereafter, the operator continuously changes and monitors each blowhole blowing flow rate sensed by the monitor 12, and the operator arbitrarily judges the blowing flow rate of the blowhole in which the blowhole flow rate is reduced for each blowhole, and the process computer of FIG. A control command is issued directly to 10 so that the electric control devices 14, 15, and 16 start the pulverized coal blowing stop / balloon purge. In addition, even when re-injecting pulverized coal, the operator must continuously monitor the blowing flow rate to the corresponding tuyere and determine that the blowing flow rate has returned to a certain level, so that the above procedure must be repeated manually.

As such, in the case of pulverized coal injection and blowout / ventilation purge by manual operation, it is not possible to control the pulverized coal injection stop and blowhole purge properly due to early detection of pulverized coal backflow due to sudden blockage of blowholes. Dog flow rate must be monitored.

An object of the present invention is to automatically control the blast furnace blow control for the pulverized coal used for reducing the manufacturing cost of the blast furnace plant and to improve the yellowing, such as suppressing the generation of inert zone under the blast furnace, by using the 34 blowholes flow rate, Provides a method to automatically detect the blockage of windballs due to the fall of windballs and the pulverization of pulverized coal ash (ASH), and to stop pulverized coal injection and purge the airflow purge to automatically prevent pulverized coal backflow due to blockages. It is.

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

4 is a hardware configuration for executing the automatic blast furnace reverse flow prevention of the present invention, it is to detect the blown ball block state by using a process computer and to automatically determine and control the pulverized coal injection decision or the pulverized coal injection stop and wind tunnel purge decision. It is composed. In order to compare the blowing flow rate detected by the blowing flow rate sensor unit 11 including a plurality of blowing flow rate sensors S ₁ -Sn installed at equal intervals along the circumferential direction of each blast furnace, Collects each blow flow rate information and sets the range of control by accepting the upper limit value and the lower limit value for blow flow rate, which are the main determinants of pulverized coal injection and blowing stop / ventilation purge according to blast furnace operating conditions and blast furnace internal conditions. In case of failure or abnormality of the range setting value input unit 17, the flow sensor measuring the blowing flow rate of the specific tuyere, or the failure or abnormality of the pulverized coal injection facility of the tuyere, the operator designates the corresponding tuyere number using the operation monitoring terminal. If you do so, the control of the blowholes will be excluded so that the blowholes in the facility abnormalities or repairs are managed separately, and An uncontrolled blowhole selection input unit 18 which provides a guide screen to the operation monitoring terminal so that the ground / bulb purge control is not performed and the operator can continuously manage whether there is an abnormality of the facility, and the control range setting value input unit ( The electric control device 14 which directly controls the pulverized coal facility by determining whether or not the control is compared with the blowing flow rates of 34 individual wind holes by using the upper limit value and the lower limit value of the blown flow rate for the pulverized coal injection and blowing stop / blower purge determined in 17). 15, 16), and a process computer 10 configured to store a final control-determined command command value in a database in order to return the current blowhole usage state (during pulverized coal injection, or pulverized coal blowing stop / burrhole purge). Consists of

The apparatus also includes battery control devices 14, 15, and 16 which execute the purge command on the pulverized coal injection and the pulverized coal injection stop / balloon according to the command of the process computer, and the electric control device includes a PLC 14 which processes an electrical signal. ), An electrical signal relay 15 for processing the on / off contact signal, and a solenoid valve 16 for performing pulverized coal injection and pulverized coal injection stop / ventilation purge of the corresponding tuyere. In the electrical control devices 14, 15, 16, the PLC 14 is programmed to receive or command the process computer 10 to actuate or stop the solenoid valve, and the relay 15 corresponds to In order to control the solenoid valve of the tuyere, on / off processing is performed according to the instruction of the PLC 14 according to the command of the process computer 10. The solenoid valve 16 is an S-way (unidirectional) solenoid valve which operates using air, and operates according to the on / off of the relay 15 according to the instruction of the PLC 14. If the relay 15 is in the on state, the solenoid valve 16 is operated by air injection, and when the solenoid valve 16 is disposed at a proper position where pulverized coal is blown, the relay 14 As 15) is off, the solenoid valve 16 is fixed in such a state that pulverized coal can be blown into the blown lance. In addition, the solenoid valve 16 can be fixed in a state capable of injecting nitrogen according to the above principle. As a result, the pulverized coal or nitrogen can be selectively supplied to the air blowing blow lance 20 through the PLC 14, the relay 15, and the solenoid valve 16 according to the instruction of the process computer 10.

5 is a flowchart of a process for automatically monitoring the blockage of the pit and preventing the pulverized coal blowing / stopping the blast of the pulverized coal and re-injecting the pulverized coal using the process computer according to the present invention.

First, the process computer 10 of the present application is a blow flow rate for the individual blow holes from the blow flow rate sensor unit 11 of each blow flow rate sensor S ₁ -Sn for 34 separate blow holes installed along the blast furnace circumferential direction. Through the control range setting value input unit 17 of the operation monitoring terminal, which collects the information and is operated by the blast furnace operation monitoring personnel, the analog blowing flow information of the blowing flow sensor 11 is passed through the instrumentation control facility (not shown). Collected individual flow rate information is converted into knife value and judged whether to control by comparing with the upper and lower limits of blow flow rate, which are the main determinants of pulverized coal injection or blowing stop / ventilation purge related to blast furnace operation conditions and blast furnace internal conditions. do. That is, when the blowing flow rate for any tuyere continues to decrease and reaches the set lower limit value, the blowing of the pulverized coal is stopped and the blowing tuyere is started. It is set to initiate re-injection of pulverized coal on arrival.

In addition, the process computer 10 operates when the flowmeter sensor that measures the blowing flow rate of a particular tuyere through the uncontrolled blower input unit 18 of FIG. 4, or the fault or abnormality of the pulverized coal injection facility of the tuyere. If you designate the relevant blowhole number by using the self-operation monitoring monitor, the control of the blowhole is excluded, so that the blowhole in the facility abnormality or repair is not managed separately to prevent pulverized coal injection or blow-off / blowhole purge control. In order to continuously manage the abnormality of the facility, the operation monitoring monitor is to provide a guide screen.

Therefore, the process computer 10 collects data of the blowing flow rate information for the individual blast holes in the blast furnace by the control range setting value input unit 17, and the upper and lower limits of the blowing flow rate for the determined pulverized coal injection or blowing stop / blower purge. It is determined whether the control is compared with the blown air flow rate of the 34 individual wind holes detected by using.

That is, the blow flow rate for any tufts of pulverized coal blown is continuously reduced to reach a lower limit for starting the pulverized coal injection and starting the tufts of purging, or the blow flow rate of the tuyere that is in the process of stopping the pulverized coal injection and the tufts of purging rises. The control target wind vent is determined by determining whether the upper limit value at which pulverized coal injection is started is reached. In addition, the process computer 10 collects the contents determined through each of the above steps, that is, the pulverized coal blowing stop / bubble purge or pulverized coal reinjection commands for each of the 34 tuyere, and directly controls the pulverized coal plant 14 ( 15 and 16 are commanded to the PLC 14, and the command command value finally controlled to give the process computer 10 a current blowhole use state (while pulverized coal injection or pulverized coal injection is stopped / ventilated balloon purge) is returned. Is stored in the database.

At this time, if the individual tuyere state check results in the injection of pulverized coal, it is checked whether or not the lower end of the tuyere flow rate is reached, and the fine coal injection is executed until the upper tuyere flow rate upper limit is reached, and the tuyere purge is executed when the tuyere flow rate is reached.

However, if the individual tuyere state is not in the pulverized coal injection, if the tuyere purge is judged whether the tuyere purge is in progress, the tuyere purge continues until the tuyere flow rate reaches the upper limit, and the re-injection of pulverized coal when the upper tuyere flow rate upper limit is reached. This blowhole purge start and pulverized coal re-injection start are executed by the operation of the relay 15 by the output data of the process computer 10 via the PLC 14 of the electric control device 14, 15, 16. Nitrogen gas is supplied to the blown lance at the start of the tuyere purge through opening / closing switching of the solenoid valve 16 by the on / off contact of (15), and at the time of blowing the pulverized coal ash, the pulverized coal is switched by the switching of the solenoid valve 16. This blown lance is retaken.

As described above, the present invention is a method that can automatically detect the pulverized coal regurgitation phenomenon and take appropriate measures according to the wind blockage during the pulverized coal injection operation at the steelworks blast furnace factory, by automating the manual monitoring management system by human. It can achieve the effect of the power, prevent the risk of large accidents that can be occurred by injecting a large amount of pulverized coal continuously, and maximize the life of the blast furnace by improving the aging conditions in high pulverized coal operation Not only that, but also the unique effect of reducing the cost of chartering due to stable operation and productivity.

Claims (1)

A flow sensor unit 11 for detecting the blowing flow rate of the blast furnace vents, and an electric control device 14 for injecting pulverized coal, stopping the pulverized coal injection / starting the purge of the pulverized coal, and reinjecting the pulverized coal according to the change of the blowing flow rate detected by the blowing flow sensor. In the blast furnace injection pulverized coal backflow prevention control method in a system including a process computer (10) for controlling the control unit, 15, 16, collecting the air flow rate information for the individual vents of the blast furnace to set the upper limit value and the lower limit value of the air flow rate In order to control the fault blowhole, after collecting the fault blowhole number to determine the control target blowhole, the state of individual blowholes is checked, and the blown flow rate detected by the blown flow sensor reaches the lower limit value of the collected blown flow rate information. Pulverized coal pulverized coal which is supposed to carry out pulverized coal injection stop / blowhole purge Non-return automatic control method.