KR100862812B1 - Apparatus for Controlling Pressure of a Hot Stove in Blast Furnace using Cold wind control valve - Google Patents

Abstract

The present invention relates to a hot blast furnace equalization control device of the blast furnace, in particular, the hot blast equalizer control of the blast furnace using a hot blast furnace for blowing hot air into the blast furnace and a cold wind control valve for controlling the equalization of the blowing period for blowing air into the hot blast furnace. Relates to a device. To this end, the present invention includes a blast furnace, a hot blast furnace for supplying hot air into the blast furnace through a hot blast pipe connected to the blast furnace, and a blower for supplying air to the hot blast furnace through a blow pipe connected to the hot blast furnace. In the blast furnace blow control system for supplying air to the hot air pipe through the cold air pipe in the blower to control the temperature of the hot air in the blast furnace hot air furnace equalization control device using a valve for controlling the cold air, the hot air in the blower Cold air control valve for controlling the flow of air in the cold air pipe supplied to the pipe; A flow rate detector for detecting a flow rate of air in the cold air pipe supplied from the blower to the hot air pipe; A flow rate setting unit for setting a flow rate of air in the cold air pipe; A flow rate adjusting unit for comparing the flow rate of the air in the cold air pipe detected by the flow rate detector with the flow rate of the air set by the flow rate setting unit, and controlling the cold air control valve according to the result value; A differential pressure detector for detecting a pressure difference between both ends of the blower and the hot stove; A differential pressure setting unit for setting differential pressure setting values at both ends of the blower and the hot air path; A differential pressure control unit for comparing the pressure difference between the both ends detected by the differential pressure detector with the differential pressure set values of the both ends set by the differential pressure setting unit, and controlling the cold air control valve according to the result value; And when the pressure difference detected by the differential pressure detector reaches a differential pressure set value set by the differential pressure setting unit, shuts off the signal connection between the cold air control valve and the flow rate control unit and controls the signal connection between the cold air control valve and the differential pressure setting unit. Flow rate and pressure control.

Blast furnace, hot stove, blower, blower pipe, hot air pipe, cold air pipe, cold air control valve, differential pressure, hot air, flow rate, blowing

Description

Apparatus for Controlling Pressure of a Hot Stove in Blast Furnace using Cold wind control valve}

1 is a configuration diagram of a pressure equalizing device according to the blowing of the conventional blast furnace hot stove.

Figure 2 is a block diagram of a pressure equalizing control device according to the blowing of the blast furnace hot stove according to the present invention.

Figure 3 is a flow chart showing a hot stove equalization control process according to the present invention.

Figure 4 is a graph showing an embodiment of the opening amount of the pressure equalizing valve according to the present invention.

5 is a graph comparing the blowing pressure fluctuations according to the present invention.

Explanation of symbols on the main parts of the drawings

20: blast furnace 25: cold air piping

26: flow rate detector 30: hot stove

31: hot air valve 32: air blowing valve

33: equalization valve 34: blower

35: cold air blocking valve 36: cold air control valve

37: blower pipe 100: temperature control unit

101: temperature setting unit 102: temperature detector

200: blower control unit 203: differential pressure detector                 

310: flow rate control part 312: flow rate setting part

315: first signal selector 316: second signal selector

320: differential pressure control unit 321: differential pressure setting unit

330: flow rate and pressure control unit

The present invention relates to a hot air fan equalization control device of the blast furnace, and more particularly, a hot air fan of the blast furnace using a hot air for blowing hot air into the blast furnace and a cold air control valve for controlling the equalization of the blowing period for blowing air to the hot blast furnace. It relates to a pressure equalizing device.

In the blast furnace, iron ore of natural origin is reduced by using carbon monoxide produced by the reaction of coke and oxygen to form molten iron. The reducing gas generated in the lower portion of the blast furnace is heated in the furnace to contact the charged raw materials to transfer heat and reduce the iron ore. In the lower part of the blast furnace, slag is produced using subsidiary materials such as calcium carbonate to prevent the required molten iron from hardening. The gas which has risen is discharged out, and the molten iron collected in the lower part is taken out as a starting point.

Hot air is blown into the blast furnace using a hot blast furnace to melt ore charged in such blast furnace operation. In general, blast furnace hot stoves are regenerated above 1300 ° C through a combustion process. On the other hand, the cold wind received from the blower passes through the regenerated hot stove to make a hot hot air blowing in the blast furnace, and the hot air passes through the inside of the blast furnace to melt the ore inside to create a molten iron.

As such, in order to transfer the blower air from the blower to the hot stove, it is important to maintain a uniform pressure in the blower and the hot wind period. The air blown from the blower is transferred to the hot air blower by opening and closing a blower valve installed between the hot air blower and the blower. In particular, when high pressure air is blown from the blower in a state in which the pressure of the hot air blower is low, there is a risk that the hot air burner may be burned out and the hot air blower may not operate properly. Therefore, after the equalization control between the blower and the hot blast furnace at the time of blast furnace work is supplied to the hot air into the blast furnace.

1 shows a configuration diagram of a pressure equalization control device according to a conventional air blowing in the blast furnace hot stove. Referring to FIG. 1, the blower 34 supplies the blower air to the hot stove 30 through the blower valve 32. The hot air furnace 30, which is regenerated through the combustion process using the combustion gas 38 and the combustion air 39, makes the blowing air supplied from the blower 34 into hot air (hot air) to form a hot air valve 31. Blow into the blast furnace 20 inside. Referring to Figure 1 will be briefly described the pressure equalization control process of the hot stove 30. In the blowing process of the hot stove 30 after the combustion process is completed and the heat storage is completed, first, the pressure equalizing valve 33 is changed by the blowing start signal of the blowing control unit 200. 30% 45 seconds, 60% 45 seconds, 100% open) to equalize between the hot stove 30 and the blower 34. At this time, the blower valve 32 is closed while the pressure equalizing valve 33 is opened and the pressure equalizing is performed. When the equalization valve 33 is opened at the predetermined time period and becomes equalized, determination of the equalization is performed by measuring the pressure at both ends of the blow valve 32 in the differential pressure detector 203 so that the pressure difference between both ends of the blow valve 32 is determined by the driver. If it is within the set range, it is determined as a uniform pressure state, the blow valve 32 is opened, and the blow air of the blower 34 is supplied to the hot air blower 30 that is stored at the high temperature. When air is supplied to the hot air fan 30, the hot air valve 31 is opened by the control signal of the blower control unit 200, and the hot air is supplied into the blast furnace 20.

As such, when the hot air valve 31 is opened, the cold air shutoff valve 35 is opened, and the temperature detector 102 detects the temperature of the hot air supplied into the blast furnace from the hot air furnace 30 and transmits the temperature to the temperature control unit 100. . If the temperature of the hot air detected by the temperature detector 102 is higher than the set value, the temperature control unit 100 opens the cold air control valve 36 to appropriately lower the temperature of the hot air. Subsequently, when the temperature detector 102 detects the temperature of the hot air and the detected temperature reaches the temperature set by the temperature setting unit 101, the temperature air control valve 36 installed in the cold air pipe 25 is closed to remove the hot air. Ensure that the temperature no longer goes down. Thus, the cold air control valve 36 is repeatedly opened or closed so that the temperature of the hot air is maintained at a set value. As described above, when the pressure equalization between the blower 34 and the hot stove 30 is completed, the blow valve 32 opens and the hot wind valve 31 opens. Subsequently, the cold air shutoff valve 35 is opened to control the hot air temperature according to the detection of the hot air temperature of the temperature detector 102.

However, in such a conventional pressure equalizing device, the total time required from the blowing of the blower 34 to the opening of the hot air valve 31 is completely different for each blast furnace, but it is from 5 minutes to 10 minutes and usually 5 minutes. If it does not completely equalize and exceeds this, it is not shown in the drawing, but since one blower of the hot stove 30 is added, the load increases to the blower 34 and the hot wind temperature decreases. There is a problem that the time is long and the combustion period is also lowered and the heat storage is lowered repeatedly. So, in order to solve such a problem, in the prior art, when the equalization of 95% was achieved before 100% equalization was made, the blow valve 32 was opened to reduce the equalization time. However, since the air pressure decreases when the pressure equalizing valve 33 is opened, the flow rate increases in the blower 34, but the distance to the blast furnace is increased, so that the pressure decreases by that distance. Since the blower valve 32 is opened and blown in a state not being%, there is a problem that the pressure is further lowered. In order to prevent this, the air flow is increased as much as the pressure decrease in the blower 34, but there is a problem that the surging of the blower 34 occurs when the excess air is completed and the surplus acts inversely during the increase. .

In order to solve the above problems, the present invention controls the flow rate and pressure of the blower air by using a cold air control valve installed in the temperature control cold air line when the pressure equalizing valve between the blower and the hot air in the initial operation of the hot air furnace. The purpose of the present invention is to provide a hot blast furnace equalization control device of a blast furnace using a cold breeze control valve that shortens the equalization time and stably controls the wind pressure when the hot blast valve is opened.

The present invention for achieving the above object, the hot air furnace for supplying hot air to the blast furnace through a hot air pipe connected to the blast furnace and the blast furnace, and supplying air to the hot blast furnace through a blow pipe connected to the hot blast furnace In the blast furnace blow control system for controlling the temperature of the hot air by supplying air to the hot air pipe through the cold air pipe in the blower in the air blower in the blast furnace hot air equalization control device using the valve for controlling the cold air in the blower, Cold air control valve for controlling the flow of air in the cold air pipe supplied to the hot air pipe from the blower; A flow rate detector for detecting a flow rate of air in the cold air pipe supplied from the blower to the hot air pipe; A flow rate setting unit for setting a flow rate of air in the cold air pipe; A flow rate adjusting unit for comparing the flow rate of the air in the cold air pipe detected by the flow rate detector with the flow rate of the air set by the flow rate setting unit, and controlling the cold air control valve according to the result value; A differential pressure detector for detecting a pressure difference between both ends of the blower and the hot stove; A differential pressure setting unit for setting differential pressure setting values at both ends of the blower and the hot air path; A differential pressure control unit for comparing the pressure difference between the both ends detected by the differential pressure detector with the differential pressure set values of the both ends set by the differential pressure setting unit, and controlling the cold air control valve according to the result value; And when the pressure difference detected by the differential pressure detector reaches the differential pressure set value set by the differential pressure setting unit, shut off the signal connection between the cold air control valve and the flow rate control unit and control the signal connection between the cold air control valve and the differential pressure setting unit. And a pressure control unit.

Here, the equalization control device is installed in the hot air pipe, the temperature detector for detecting the temperature of the hot air supplied into the blast furnace, the temperature setting unit for setting the set temperature of the hot air, and the hot air detected by the temperature detector It further comprises a temperature control unit for comparing the temperature and the temperature of the hot air set by the temperature setting unit and controls the cold air control valve according to the result.

Further, the differential pressure control unit controls the differential pressure at both ends until the pressure is equalized between the blower and the hot stove.

The present invention provides a pressure equalization by using a cold air control valve installed in a cold air line for temperature control of hot air to solve the above problems caused by opening and closing the pressure equalization valve installed between the hot air furnace and the blower during the hot air pressure equalization. The parallel operation shortens the equalization time, promotes the stabilization of the wind pressure, controls the cold wind flow rate and pressure, and controls the pressure fluctuations of the hot wind blown to the blast furnace when replacing the hot blast furnace to minimize the effect of the pressure of the hot wind on the operation and stabilize the operation. Provided is a hot blast equalization control device of the blast furnace to enable this.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail the present invention.

2 is a block diagram of a pressure equalizing device according to the blowing of the blast furnace hot stove according to the present invention. As shown in FIG. 2, the pressure equalizing device according to the present invention includes a flow rate detector 26 installed in a cold air pipe 25 for controlling hot air temperature and detecting a flow rate of the cold air pipe 25, and the cold air pipe 25. Flow rate setting unit 312 for setting the flow rate of the flow rate control unit for controlling the cold air control valve 36 by comparing the flow rate value detected by the flow rate setting unit 312 with the flow rate value detected by the flow rate detector 26 Part 310, the differential pressure setting unit 321 for setting the differential pressure between the hot air path 30 and the blower 34, the blower pipe 37 to which the blowing air is transmitted from the blower 34 to the hot air path (30) Differential pressure control unit 320 for controlling the cold air control valve 36 by receiving the differential pressure value detected by the differential pressure detector 203 for detecting the pressure difference between the two ends of the blow valve 32 installed in the Receiving the temperature value of the hot air detected by the temperature detector 102 to detect the cold air control valve 36 Temperature control unit 100 to control, the first signal selection unit 315 responsible for the signal connection of the flow rate setting unit 312 and the flow rate control unit 310, the cold air control valve 36 and the temperature control unit ( 100), a second signal selector 316 for signal connection with the flow rate control unit 310 or the differential pressure control unit 320, and a flow rate and pressure control unit 330 for controlling the first and second signal selectors. It consists of. Hereinafter, the operation of the equalization control apparatus according to the present invention will be described with reference to FIG. 2.

When the blower air is supplied from the blower 34 to the hot blast furnace 30, the blower air is simultaneously supplied to both the blower pipe 37 and the cold air pipe 25. When the blowing control unit 200 transmits a blow start signal to the pressure equalizing valve 33, the pressure equalizing valve 33 is less than the previously described opening degree (for example, 10% 45 seconds, 30% 45 seconds, and 70% open). Opening is less than conventional charge flow rate. At the same time, the blowing control unit 200 opens the cold air blocking valve 35. In addition, according to the control signal of the flow rate and the pressure control unit 330, the first signal selector 315 is set to 2, the second signal selector 316 is set to 2, so that the flow rate control unit 310 flow rate The cold air control valve 36 is controlled to control the flow rate of the cold air pipe 25 at the flow rate set by the setting unit 312. At this time, the flow rate detector 26 detects the flow rate of the cold air pipe 26 and feeds it back to the flow rate control unit 310, and the flow rate control unit 310 and the flow rate value detected by the flow rate detector 26 and the The flow rate set by the flow rate setting unit 312 is compared to control the opening and closing degree of the cold air control valve 36 as a result value.

In this state, the differential pressure detector 203 detects the pressure difference across the blow valve 32 installed in the blower pipe 37, and transmits the pressure difference to the differential pressure control unit 320 and the flow rate and pressure control unit 330. When the pressure difference reaches the differential pressure set value (90% of the equal pressure state) set in the differential pressure setting unit 321, the flow rate and pressure controller 330 controls the second signal selector 316 to control the second signal selector. By setting 316 to No. 3, the control unit switches to the differential pressure control mode, whereby the differential pressure control unit 320 continuously controls the differential pressure by controlling the cold air control valve 36 in accordance with the transmitted differential pressure signal.

Subsequently, when the pressure difference detected by the differential pressure detector 203 reaches a blowable set value (balanced pressure state) set by the driver, the blow valve 32 is opened by a control signal of the blow control unit 200 and at the same time a hot air valve ( 31) is opened to start the supply of hot air, and the differential pressure control is continued until the blow valve 32 is opened 100%.

When the pressure is continuously equalized and the supply of hot air is started into the blast furnace, the hot air temperature detector 102 for detecting the temperature of the hot air detects the temperature of the hot air, and the flow rate and pressure control unit 330 performs the second signal selector ( 316 is controlled to set the second signal selector 316 to No. 1, and the temperature controller 100 controls the cold air control valve 36 according to the temperature value detected by the temperature detector 102 to hot air. To control the temperature.

As described above, the hot blast equalization control apparatus according to the present invention, the pressure is initially equalized through a pressure equalizing valve 33 installed in the blower pipe 37, and at the same time the cold air piping in the flow rate control unit 310 Equalization is carried out in parallel through the cold air control valve 36 installed in the (25), and since the differential pressure detector 203 at 90% of the pressure equalization state from the differential pressure control unit 320, the cold air control valve 36 To control the differential pressure. Subsequently, when the pressure is equalized and the hot air is supplied into the blast furnace 20, the temperature of the supplied hot air is detected and the hot air is controlled through the cold air control valve 36 in the temperature control part 100 according to the detected hot air temperature. To control the temperature.

3 is a flowchart illustrating a hot stove equalization control process according to the present invention. This will be described with reference to FIG. 3. First, when the blower 34 supplies the blower air to the hot stove 30, in order to make the pressure state between the hot stove 30 and the blower 34 uniform (to equalize), the blower control unit 200 The pressure equalizing valve 33 is opened by the control signal (S301). At this time, the equalization valve 33 is preferably opened in 10% 45 seconds-> 30% 45 seconds-> 70% 45 seconds, as shown in FIG. 4 is a graph showing an embodiment of the opening amount of the pressure equalizing valve 33 according to the present invention. Immediately after the equalizing valve 33 is opened, the cold air blocking valve 35 installed in the cold air pipe 25 is opened by the control signal of the blowing control unit 200 (S302). Subsequently, the flow rate and pressure controller 330 controls the first signal selector 315 and the second signal selector 316 to set the first signal selector 315 to No. 2 and select the second signal. The unit 316 is set to number 2 (S303). This starts the flow control. The flow rate value signal set by the flow rate setting unit 312 is transmitted to the flow rate control unit 310 through the first signal selector 315, and the flow rate control unit 310 transmits the set flow rate value and the flow rate detector 26. The flow rate is controlled by comparing the flow rate value in the cold air pipe 25 detected by the control unit and controlling the cold air control valve 36 according to the result value.

Subsequently, it is determined whether or not the pressure difference across the blow valve 32 detected by the differential pressure detector 203 reaches the differential pressure set value (a time point at which 90% of the pressure equalization state) set by the differential pressure setting unit 321 is reached (S304). When the differential pressure at both ends reaches the differential pressure set value, the flow rate and pressure controller 330 controls the first signal selector 315 and the second signal selector 316 to determine the differential pressure at both ends. The first signal selector 315 is set to No. 1 and the second signal selector 316 is set to No. 3 (S305). This starts the differential pressure control. Subsequently, it is determined whether the differential pressure across the blow valve 32 detected by the differential pressure detector 203 reaches a blowable set value (pressure equalizing state) set by the driver (S306). If it is determined in step S306 that the differential pressure at both ends reaches the blowable set value (pressure equalization state), the blow valve 32 is opened (S307). In this way, the blower air is supplied from the blower 34 to the hot stove 30 through the open blower valve 32 in a uniform pressure state.

Subsequently, the hot air valve 31 is opened to supply hot air into the blast furnace 20 (S308). When the hot air valve 31 is opened, the flow rate and pressure controller 330 controls the second signal selector 316 to set the second signal selector 316 to No. 1 (S309). This starts the temperature control of the hot air. That is, the temperature of the hot air supplied into the blast furnace 20 is detected by the temperature detector 102 and transmitted to the temperature controller 100, and the temperature controller 100 compares the detected hot air temperature with a set hot air temperature. As a result, the temperature of the hot wind is controlled by controlling the cold air regulating valve 36. In general, since the temperature of the hot wind coming from the hot stove 30 is higher than the temperature required for the operation of the blast furnace 20, the cold air control valve 36 is opened to put cold air into a pipe through which the hot wind passes, thereby reducing the temperature of the hot wind. Let's do it.

5 is a graph showing a comparison of the blowing pressure fluctuation according to before and after the application of the present invention, Figure 5 (a) is a graph showing the air flow rate and the wind pressure when the conventional pressure control device is applied and Figure 5 (b) is the present invention It is a graph showing the air flow rate and the wind pressure when the pressure equalizing device according to the present invention is applied. First, referring to FIG. 5 (a), reference numeral X denotes a wind pressure drop at the time of opening the equalization valve 33. This is because the high pressure on the blower 34 side and the low pressure on the hot stove 30 side increases the flow rate in the blower 34 at the moment of opening the pressure equalizing valve 33, but the distance from the blower 34 to the hot air blower 30 is far. This is because the wind pressure is further reduced by the distance. In addition, reference numeral Y denotes an increase due to excess wind pressure when opening the equalization valve 33. This is because the amount of air flow as much as the pressure drop is increased in the blower 34, but while the increase is already completed, the excess air is reversed. Reference numeral Z denotes a flow rate supplement of the blower 34. This increases the amount of air by the pressure drop as described above.

However, referring to Figure 5 (b), it can be seen that the conventional X, Y, Z fluctuations are resolved to be a stable blowing flow rate and blowing pressure fluctuation. That is, it can be seen that the wind pressure increase after blowing due to the pressure difference is eliminated at X '. In addition, it turns out that Y 'and Z' also eliminated the above-mentioned conventional fluctuation value.

The above description and the description of the drawings are in accordance with one embodiment of the present invention will be possible to substitute, change or modify the components within the scope without departing from the spirit of the present invention. In particular, it will be readily understood by those skilled in the art that the set values of flow rate and differential pressure and the opening amount of various valves may be changed to other values upon application of the present invention.

As described above, according to the present invention, the equalization time is shortened at the front end and the rear end of the blast furnace hot blast furnace, and the pressure equalization time is shortened. Hunting is minimized, and 100% equalization is done in a short time, so it is possible to stabilize the pressure after the completion of the blow, thereby reducing the load on the blower and minimizing the fluctuation of the furnace due to the fluctuation of the air volume.

Claims (3)

And a blower for supplying hot air to the blast furnace through a hot air pipe connected to the blast furnace, and a blower for supplying air to the hot blast furnace through a blow pipe connected to the hot blast furnace. In the blast furnace hot air furnace equalization control device using a cold air control valve in the blast furnace blowing control system for supplying air to the hot air pipe through the cold air pipe to control the temperature of the hot air, Cold air control valve for controlling the flow of air in the cold air pipe supplied from the blower to the hot air pipe; A flow rate detector for detecting a flow rate of air in the cold air pipe supplied from the blower to the hot air pipe; A flow rate setting unit for setting a flow rate of air in the cold air pipe; A flow rate adjusting unit for comparing the flow rate of the air in the cold air pipe detected by the flow rate detector with the flow rate of the air set by the flow rate setting unit, and controlling the cold air control valve according to the result value; A differential pressure detector for detecting a pressure difference between both ends of a blow valve installed in a blow pipe through which blow air is transferred from the blower to the hot stove; A differential pressure setting unit for setting a differential pressure setting value at both ends of the blower valve; A differential pressure control unit for comparing the pressure difference detected by the differential pressure detector with the differential pressure set value set by the differential pressure setting unit and controlling the cold air control valve according to the result value; And When the pressure difference detected by the differential pressure detector reaches the differential pressure set value set by the differential pressure setting unit, the flow rate for blocking the signal connection of the cold air control valve and the flow rate control unit and controlling the signal connection of the cold air control valve and the differential pressure setting unit; Hot blast furnace equalization control device of the blast furnace using a cold air control valve, characterized in that it comprises a pressure control unit. The method of claim 1, A temperature detector installed in the hot air pipe to detect a temperature of hot air supplied into the blast furnace; A temperature setting unit for setting a set temperature of the hot air; And And a temperature control unit for comparing the temperature of the hot air detected by the temperature detector with the temperature of the hot air set by the temperature setting unit and controlling the cold air control valve according to the resultant value. Hot blast furnace equalization control device of blast furnace. According to claim 1, wherein the differential pressure control unit, Hot air furnace equalization control device of the blast furnace using a cold air control valve, characterized in that for controlling the pressure difference between the both ends until the pressure between the blower and the hot air path is made.

Images