KR100398408B1 - Apparatus for controlling pressure in hopper of blast furnace - Google Patents

Abstract

The present invention relates to a top raw material hopper pressure control device, the present invention is a top raw material hopper pressure control device, the hopper differential pressure detector (2a) for detecting the hopper and the pressure difference in the furnace; A hopper raw material differential pressure controller (2d) for performing PID control on the detection signal of the hopper differential pressure detector (2a); A hopper back pressure controller 23 for comparing the output signal of the hopper material differential pressure controller 2d with a back pressure set value and determining whether to perform back pressure by adjusting the back pressure blocking valve 21 and the back pressure control valve 22 to perform back pressure; When the hopper differential pressure rises due to the rise of the top pressure, the emergency discharge valve is opened and recovered to the rear stage of the static pressure generator through the gas recovery line, thereby suppressing the air discharge of the blast furnace gas and maintaining a stable top pressure. To control.

Description

Aggregate raw material hopper pressure controller {APPARATUS FOR CONTROLLING PRESSURE IN HOPPER OF BLAST FURNACE}

The present invention relates to a pressure control device for the top raw material hopper, and in particular, by establishing a back pressure control function in the raw material hopper, when the hopper differential pressure rises due to the rise in the top pressure, the emergency discharge valve is opened to open the back pressure without the back pressure. The present invention relates to a top raw material hopper pressure control device which suppresses the air discharge of blast furnace gas and controls a stable top pressure by recovering it to the rear stage of the constant pressure generator.

In general, the raw material weighed from the raw material basis hopper 15 is transported to the conveyor belt 15a and stored in the top hoppers 2 and 3, and then blast furnace gas (Gas) and nitrogen (N2) gas are used for the hopper (2). It is a facility that produces molten iron by reducing the cokes by charging the raw material into the lower furnace 1b after raising the pressure of the furnace 1b to match the pressure of the furnace 1b.

The raw material loading and differential pressure control method of the raw material hopper will be described with reference to FIG.

The raw material weighed in the raw material basis hopper 15 is transported to the upper part of the blast furnace 1 using the conveyor belt 15a, and then stored in the raw material hopper 2, and the stored raw material is charged into the lower furnace 1b. In order to do this, the pressure of the top raw material hopper 2 and the lower furnace 2b must be matched (equalized) to carry out charging.

Therefore, the pressure equalizing valve EV1 12 is opened to pressurize the semi-clean gas (Gas) through the line 121 connected to the front of the clean equipment 7 to the raw material hopper 2 to increase the pressure, and the first pressure equalization. Will complete. When the first pressure equalization completion is detected by the top hopper differential pressure detector 2a, the secondary pressure shutoff valve 2c is opened to perform the pressure equalization by performing nitrogen secondary pressure with nitrogen (N2) gas, and the pressure equalization is completed. When the raw material in the hopper (2) is charged to the lower furnace (2).

When the completion of loading (weight low) is detected by the raw material hopper weight detector (2h), charging to the furnace is completed and back pressure in the hopper to reload the raw material into the hopper, and this back pressure is the back pressure line 131 The gas recovery shutoff valve 13 provided at the opening is opened to back up the pressure in the hopper to the rear end of the stationary pressure generator 9. When the low pressure signal is detected by the back pressure detector 2f and the back pressure is completed, the raw material weighed by the raw material weighing machine 15 is stored in the top raw material hopper 2 and then charged into the furnace 1b. As described above, the molten iron is produced and drawn out by the reducing action of cokes in the blast furnace 1b.

In the conventional method of controlling the differential pressure of the raw material hopper (2), when the primary equalization shutoff valve (EV1; 12) is opened, the semi-cleaned gas in front of the clean facility (7) is recovered into the hopper and the primary pressure rises. Then, the secondary equalization shutoff valve EV2; 2c is opened to raise the target pressure to equalize the furnace 2b. When the pressure equalization is completed, the secondary pressure equalization shut-off valve 2c is closed and the pressure equalization control valve 2b is fully closed to pressurize the nitrogen gas into the hopper, and the pressure is completed, so that the pressure is completed. When the pressure equalization of (2b) is completed, charging of a raw material starts to furnace. At this time, since the pressurized raw material hopper 2 is in a pressurized state, unless there is a special abnormality of the hopper, the pressure drop does not occur and is kept constant.

However, the fault pressure control line (furnace 2b, dust collector 5, gas cleaning equipment 6, 7, static pressure control valve 8, static pressure generator 9) and the fault pressure control system are abnormal. When the pressure is lower than the pressure of the raw material hopper 2, the pressure on the low side of the differential pressure detection side is lowered. Therefore, the differential pressure of the raw material hopper suddenly rises to indicate the set value (0.18 Kg / cm 2 or more). When the hopper gas emergency discharge valve (14) installed on the top of the raw material hopper (2) is opened to protect the equipment (hopper hopper damage), the pressure back to the atmosphere. Here, the top raw material hopper of the differential pressure detector is detected on the differential pressure detection high side and the furnace pressure is detected on the differential pressure detection low side.

At this time, since the pressure in the furnace 2 also decreases instantaneously, the control of the top pressure is poor, and the operation of the furnace 2, the operation of the top pressure generator 9, and the hot blast furnace 4 combustion control, etc. A disturbance factor is caused.

As described above, in the conventional method of controlling the differential pressure of the raw material hopper 2, the differential pressure of the raw material hopper 2 is generated when the internal pressure (the constant pressure) rises, thereby controlling the static pressure and the static pressure due to the opening of the emergency discharge valve 14. Even if problems such as generator operation and hot stove combustion occur, there is no countermeasure.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and therefore, an object of the present invention is to establish a back pressure control function in a raw material hopper so that an emergency discharge valve is opened to open back pressure when the hopper differential pressure rises due to a rise in the top pressure By recovering to the rear end of the stationary pressure generator through the gas recovery line without providing a top raw material hopper pressure control device to suppress the air emissions of the blast furnace gas and to control the stable top pressure.

1 is a block diagram of a conventional top raw material hopper pressure control device.

Figure 2 is a block diagram of a raw material hopper pressure control device according to the present invention.

Figure 3 is a top raw material hopper differential pressure control time chart according to the present invention.

4 is a flowchart showing a control process according to the present invention.

Explanation of symbols on the main parts of the drawings

1: Blast Furnace 2,3: Hopper Raw Material Hopper

2a: Hopper differential pressure detector 2b: Hopper equalization control valve

2c, 12: Hopper equalization blocking valve 2d: Hopper differential pressure controller

2f: Hopper pressure detector 2g: Hopper pressure low setter

2h: Hopper weight detector 2i: Hopper weight high setter

2j: Hopper weight low setter 2k: Hopper differential pressure 1st high setter

4: Hot Stove 5: Dust Catcher

6,7: Cleaner equipment 8: Septum valve

9: static pressure generator 10: gas hold (Gas Hold)

11: nitrogen (N2) storage tank 13, 21: gas recovery shutoff valve

14 gas emergency discharge valve 15 raw material basis weight hopper (hopper)

5a: Conveyor Belt 22: Hopper Back Pressure Control Valve

23: Hopper back pressure controller

As a technical means for achieving the above object of the present invention, the apparatus of the present invention comprises a hopper differential pressure detector for detecting a pressure difference between the hopper and the furnace in the raw material hopper pressure control device; A hopper raw material differential pressure controller for performing PID control on the detection signal of the hopper differential pressure detector; A hopper back pressure controller for performing back pressure by comparing the output signal of the hopper material differential pressure controller with a back pressure set value and determining whether to perform back pressure by adjusting a back pressure blocking valve and a back pressure control valve; Characterized in having a.

EMBODIMENT OF THE INVENTION Hereinafter, the top raw material hopper pressure control apparatus which concerns on this invention is demonstrated in detail with reference to attached drawing. In the drawings referred to in the present invention, components having substantially the same configuration and function will use the same reference numerals.

FIG. 2 is a configuration diagram of a top raw material hopper pressure control device according to the present invention. Referring to FIG. 2, in the top raw material hopper pressure control device according to the present invention, a hopper differential pressure detector 2a for detecting a hopper and an internal pressure difference in the furnace is shown. ) And the output signal of the hopper raw material differential pressure controller 2d for PID control of the detection signal of the hopper differential pressure detector 2a and the output signal of the hopper raw material differential pressure controller 2d to determine the back pressure. And a hopper back pressure controller 23 for controlling the back pressure blocking valve 21 and the back pressure control valve 22 to perform back pressure.

Further, the above-mentioned raw material hopper pressure control device includes a hopper weight detector 2h for detecting the raw material weight of the hopper, a hopper pressure detector 2f for detecting the pressure of the hopper, and a detection signal of the hopper weight detector 2h. The detection signal of the hopper weight high setter 2i and the hopper differential pressure detector 2a which perform the first equalization by opening the hopper primary equalization blocking valve 12 by judging raw material loading by comparing the weight high set value By comparing the primary differential pressure set value, judging completion of the primary equalization pressure, the hopper primary equalization blocking valve 12 is closed, and at the same time, the hopper secondary equalization blocking valve 2c is opened to switch from primary equalization to secondary equalization. A pressure control valve for performing secondary equalization by adjusting the hopper equalization control valve 2b according to the differential pressure by comparing the output signal of the hopper differential pressure primary setter 2k and the hopper raw material differential pressure controller 2d with the pressure set value. Detection scene of the setter 24 and the hopper weight detector 2h The hopper weight low setter for closing the hopper secondary equalization shutoff valve 2c by opening the gas recovery shutoff valve 13 and judging the completion of charging by comparing the weight low set value with 2j) and a hopper pressure low setter 2g for closing the gas recovery shutoff valve 13 to terminate the back pressure by comparing the detected voltage of the hopper pressure detector 2f with the back pressure complete set value to determine the back pressure completion. It includes more.

3 is a top raw material hopper differential pressure control time chart according to the present invention, Figure 4 is a flow chart showing a control process according to the present invention.

Operation according to the device of the present invention configured as described above will be described in detail below based on the accompanying drawings.

The present invention, through the first and second pressurization and back pressure process, to detect the rise in the differential pressure of the raw material hopper (2) to be able to back pressure while controlling the stable differential pressure to suppress the air emissions of blast furnace gas (Gas) and stable open pressure The control enabled stable blast furnace operation.

Referring to FIGS. 2 to 4, the first equalization (pressurization) process according to the present invention will be described. First, the raw material weighed in the raw material weighing machine 15 is conveyed to the top part by the belt conveyor 15a to feed the raw material hopper ( 2) is filled.

When the raw material is filled in the raw material hopper 2 as described above, the signal detected by the weight detector 2h is input 50a to the "+" side of the op amp 50 of the high weight setter 2i. This detection signal is compared with the signal set by the volume setting device 50b, and when the input detection signal 50a is larger than the setting signal 50b, the transistor Q1 is turned on, thus relay R3; .50d ) Is driven (On) to open the primary equalization blocking valve (EV1; 12) of the raw material hopper (2) to open the gas between the clean facilities (6, 7) the primary equalization blocking valve (EV1; 12). ) Is pressurized into the raw material hopper (2) to carry out the first equalization.

During such primary pressurization, the raw material hopper differential pressure detector 2a detects the differential pressure, and this detection signal 60a is inputted to the differential pressure primary setter 2k and compared with the set signal 60b. At this time, when the input signal is input higher than the set signal, the relay R4; 60d is turned on by the driving of the transistor Q2, thereby closing the primary equalization blocking valve EV1; 12 and closing the secondary. The pressure equalizing shutoff valve EV2; 2c is opened to pressurize the nitrogen gas into the raw material hopper 2 through the secondary equalizing shutoff valve EV2; 2c to perform secondary pressurization of the raw material hopper.

While performing the secondary pressurization, if the pressure of the hopper is higher than the pressure in the furnace, a back pressure process for discharging the gas of the raw material hopper 2 is performed. When the back pressure process is described, it is detected by the raw material hopper differential pressure detector 2a. The input signal is input to the indication value (31b) (PV: Process Variable) of the raw material hopper differential pressure controller 2d, and when the signal of the set volume 31s of the differential pressure setter is input, the control inside the controller is controlled. After an operation (PID control, that is, proportional, derivative, and integral), an output signal (MV: Manipulative Variable) 31o is output through the op amp.

The output signal 31o is provided to the differential pressure control valve 2b through the pressure control valve setter 24 to close the control valve to stop the secondary equalization, and the back pressure control valve 23 through the hopper back pressure controller 23. 22) to open the control valve and discharge the gas of the raw material hopper (2) through the back pressure control valve 22 to the rear of the gas recovery shut-off valve 13 to perform the back pressure, so that the raw material hopper (2) It is to control the pressure constantly.

The differential pressure controller output signal 31o is input to the op amp 80 "-" side of the pressure control valve setting circuit 24 and the signal set by the set volume (80b) (50%) on the "+" side. Is input. At this time, since there is no pressure in the hopper during the initial pressurization of the raw material hopper 2, a signal of 50% or more is output to the output signal 31o of the differential pressure controller. Accordingly, the pressure control valve (2b) is opened to increase the pressure of the raw material hopper to achieve a pressure equalization with the pressure in the furnace (1b).

On the other hand, since the setting of the hopper differential pressure 31s usually sets 0.0kg / cm 2, when the pressure of the hopper rises and the pressure and equalization in the furnace are performed, the hopper pressure control valve 2b is closed and stops pressurization. When the pressure decreases, the raw material differential pressure increases, and the hopper gas emergency discharge valve (ERV) 14 opens to back up the pressure inside the hopper to the atmosphere. At this time, since the pressure in the furnace also has a significant effect, it has a lot of adverse effects on the control of the top pressure and blast furnace operation. Therefore, in the present invention, the back pressure line is newly installed in the raw material hopper 2, and the back pressure shut-off valve 21, the back pressure control valve 22, and the back pressure control circuit 23 are newly operated.

As described above, when the pressure equalization of the raw material hopper 2 is completed (2) and the loading pressure decreases while charging the raw material in the hopper into the furnace 1b, the output signal MV of the raw material hopper differential pressure controller 2d is 31c. ) Is raised to indicate 50% or more, and this output signal is input 70a to the op amp 70 "+" side of the back pressure control circuit 23, and the signal (2.5V) set on the "-" side. When rising, the output signal is outputted to the back pressure control valve 22 to operate the valve, and at the same time, the relay R5 (70d) is driven to open the back pressure shutoff valve 21 to set the pressure inside the hopper (0.0). kg / cm 2) to gradually back pressure.

By performing such hopper back pressure control, the problem of back pressure of the blast furnace gas caused by the opening of the gas discharge valve 14 due to the increase in the hopper differential pressure is improved.

First, the loading completion detection of the raw material in the hopper into the blast furnace (1b) is gradually reduced in weight as the charging time elapses, at which time the signal detected by the weight detector (2h) is a low detection circuit (2j) Is inputted to the low setting signal 30b and detected below the set value, the relay R1; 30d of the transistor Q3 is driven to close the equalization blocking valve EV2; 2c, and the gas recovery blocking valve GRV1; The pressure inside the hopper is opened to the rear end of the stationary pressure generator 9, and the pressurized gas is recovered without being backpressured into the atmosphere and reused.

Thus, while performing back pressure, the completion of pressurization gas recovery detects the pressure in the hopper back pressure detector 2f and inputs the back pressure low setting circuit 2g to the op amp 40 "-" side to detect it than the set signal 40b. When the pressure is lowered, a signal 40c is output to drive (On) the transistor Q4 to output a contact of the relay R2; 40d to close the gas recovery shutoff valve 13 to complete the raw material loading process. .

As the raw material hopper of the above-described top hopper is repeated, the raw material is charged into the blast furnace 1b to produce molten iron by the reduction of cokes in the blast furnace.

Regarding the above, with reference to the time chart shown in FIG. 3 and the flowchart of FIG. 4, the following briefly describes the following.

Referring to FIG. 3, when the raw material conveyed from the raw material weighing machine is loaded into the raw material hopper and the weight of the hopper is indicated above the set value (101), the equalization blocking valve EA1 is opened to pressurize the raw material hopper to pressurize the pressure in the furnace. The equalization is performed first (corresponding to steps 201 to 203 of FIG. 4).

At this time, the first equalization completion differential pressure setting value is normally set to 0.0kg / ㎠, when the pressure reaches the first equalization set value, the first equalization completion 106 is detected and the first equalization shutoff valve 12 is closed. The secondary equalization blocking valve EV2; 2c is opened to perform secondary equalization (corresponding to steps 204 to 205 of FIG. 4).

As such, when the differential pressure is reached and the differential pressure set value (0.0 kg / cm 2) is reached, the pressure equalization completion 107 is detected and the raw material in the hopper is charged into the lower furnace (corresponding to step 206 of FIG. 4).

As the charging progresses, when the charging weight gradually decreases during charging into the furnace and is detected below the set value, the charging completion 103 is detected and the charging of raw materials into the furnace is finished. When charging is completed, the pressure in the hopper is recovered by opening the hopper gas recovery shutoff valve (GRV1; 13) without back pressure into the atmosphere (corresponding to step 207 of FIG. 4). While performing charging in step 207 of FIG. 4, the pressure of the hopper is kept constant by performing the secondary equalization process and the back pressure process as soon as the pressure difference is generated while continuously monitoring in the hopper.

As described above, the conventional problem of pressure backing the pressure in the raw material hopper to the atmosphere is improved by opening the gas emergency discharge valve (ERV) 14 due to the differential pressure rise during the inboard furnace after completion of the pressure equalization. It is all recovered through.

As described above, the present invention provides a static pressure generator through a back pressure control valve 22 without backing the pressure in the raw material hopper to the atmosphere when the differential pressure rises due to the abnormal pressure over the raw material in the raw material hopper 2 into the furnace. (8) It is possible to improve the blast furnace operation by preventing air pollution, stabilization of pressure control of the atmosphere, stabilization of yellowing control, etc. by recovering to the rear stage and reusing it as a gas for combustion in a hot stove.

Claims (2)

In the raw material hopper pressure control device, A hopper differential pressure detector 2a for detecting a pressure difference between the hopper and the furnace; A hopper raw material differential pressure controller (2d) for performing PID control on the detection signal of the hopper differential pressure detector (2a); A hopper back pressure controller 23 for comparing the output signal of the hopper material differential pressure controller 2d with a back pressure set value and determining whether to perform back pressure by adjusting the back pressure blocking valve 21 and the back pressure control valve 22 to perform back pressure; The raw material hopper pressure control device characterized in that it comprises a. According to claim 1, wherein the raw material hopper pressure control device A hopper weight detector 2h for detecting a raw material weight of the hopper; A hopper pressure detector 2f for detecting the pressure of the hopper; A hopper weight high setter 2i for comparing the detection signal of the hopper weight detector 2h with the weight high set value to determine the loading of the raw material to open the hopper primary equalization blocking valve 12 to perform the first equalization; The detection signal of the hopper differential pressure detector 2a compares the primary differential pressure set value to determine completion of the primary equalization pressure, thereby closing the hopper primary equalization blocking valve 12 and simultaneously opening the hopper secondary equalization blocking valve 2c. A hopper differential pressure primary setter 2k for converting from primary equalization to secondary equalization; A pressure control valve setter 24 for performing secondary equalization by adjusting the hopper equalization control valve 2b according to the differential pressure by comparing the output signal of the hopper raw material differential pressure controller 2d with the pressure set value; By comparing the detection signal of the hopper weight detector (2h) with the weight low set value, the completion of charging is judged to close the hopper secondary equalization blocking valve (2c), and the gas recovery shutoff valve (13) is opened to back pressure at the secondary pressure. A hopper weight row setter 2j to switch to; And a hopper pressure low setter (2g) which closes the gas recovery shutoff valve 13 to terminate the back pressure by comparing the detected voltage of the hopper pressure detector 2f with the back pressure complete set value to determine the back pressure completion. The raw material hopper pressure control device, characterized in that.