KR20040048734A - An apparatus for controlling the hot blast in pulverized coal manufacturing system - Google Patents

Abstract

PURPOSE: An apparatus for controlling hot blast in pulverized coal manufacturing line is provided to reduce oxygen concentration in hot blast by removing moisture from exhaust gas exhausted from the bag filter to the air and controlling temperature and flow rate of the exhaust gas before supplying to the pulverized coal manufacturing line. CONSTITUTION: The apparatus comprises an exhaust gas recovery line(20L) for transferring exhaust gas of bag filter to the front side of crusher by a pipe for connecting gas exhaust port of the bag filter and the front side of the crusher; a drier(21) installed at the bag filter exhaust gas recovery line to remove moisture of exhaust gas exhausted from the bag filter; an exhaust gas temperature detector(22) installed at the bag filter exhaust gas recovery line to detect temperature of exhaust gas passing through the drier; an exhaust gas temperature control valve(23) installed on a pipe branched off from the bag filter exhaust gas recovery line between the drier and the exhaust gas temperature detector to control amount of the air supplied to the bag filter exhaust gas recovery line; an exhaust gas temperature control part(30) for controlling opening degree of the exhaust gas temperature control valve so that exhaust gas temperature detection values of the exhaust gas temperature detector are the same as a preset exhaust gas temperature value; an exhaust gas flow rate control valve(25) installed in rear of the exhaust gas temperature detector on the bag filter exhaust gas recovery line to control supply amount of exhaust gas supplied to the front side of the crusher; a hot blast flow rate sensing part(60) for generating switch signals if detected flow rate values of hot blast flow rate detector are greater than a preset flow rate value; and a hot blast temperature control part(80) for controlling opening degree of the exhaust gas flow rate control valve so that the inputted temperature detection values of the temperature detector are the same as the preset temperature value if the switching signals are generated in the hot blast flow rate sensing part.

Description

Hot air control device in pulverized coal manufacturing facility {AN APPARATUS FOR CONTROLLING THE HOT BLAST IN PULVERIZED COAL MANUFACTURING SYSTEM}

The present invention relates to an apparatus for controlling the oxygen concentration in the hot air in the manufacturing facility of pulverized coal blown into the blast furnace during the steelmaking process, and more particularly, to recover the exhaust gas discharged to the atmosphere from the bag filter to reduce the oxygen concentration in the hot air. The present invention relates to a hot air control device in a pulverized coal manufacturing facility for removing moisture and controlling the temperature and flow rate of the exhaust gas from which water is removed to supply the pulverized coal production equipment.

In general, the hot air is a mixture of exhaust gas and atmospheric air, the exhaust gas is discharged from the hot blast furnace and the atmospheric air is sucked through the atmospheric air inlet and supplied to the pulverized coal production equipment. The temperature of the exhaust gas is approximately 180 to 210 ° C., and is supplied to the crusher along the pipe by the inhaler, and then passed to the bag filter together with the pulverized coal in the crusher. The hot air is used as a drying gas for crushing coal into pulverized coal in the crusher, and is also used as a transfer gas for transferring pulverized coal to the bag filter.

1 is a block diagram showing a conventional hot air control device in the pulverized coal production equipment, and FIG. 3 is an operation timing diagram of the conventional hot air control device. Referring to FIGS. 1 and 3, a conventional hot air control device will be described in the pulverized coal production equipment. do.

When coal is charged into the coal storage hopper 5 through the belt conveyor 4, the inhaler 2 is rotated and hot air is sucked in. At this time, the coal supply amount setting unit 40 sets the coal supply minimum value to supply the coal feeder 6 ) And the hot air flow rate calculation unit 50 controls the amount of coal supply and the hot air flow rate.

When hot air is sucked in and the temperature of the shredder outlet temperature detector 8 reaches 80 ° C., the pulverized coal production equipment is regarded as sufficiently preheated, and the driver starts the shredder 7. When the crusher 7 is started and a predetermined time, about 15 to 20 seconds has elapsed, the coal feeder 6 is activated by the minimum amount of the coal feed amount of the coal feed amount setting unit 40 so that coal in the coal storage hopper 5 is discharged. It is discharged to the crusher 7. The hot air conveyed with the pulverized coal to the crusher 7 is discharged into the atmosphere through the gas outlet above the bag filter 9, and the pulverized coal is collected and blown into the blast furnace.

In addition, the minimum amount of feedstock output to the hot air flow rate calculation unit 50 is converted into a hot air flow rate by the flow rate curve in the hot air flow rate calculation unit 50 and output to the hot air flow rate control unit 70. The hot air flow rate control unit 70 increases the opening degree of the exhaust gas control valve 10 when the flow rate detection value detected by the hot air flow rate detector 3 is smaller than the flow rate setting value of the hot air flow rate calculation unit 50. If the detected value is larger than the flow rate setting value, the opening degree of the exhaust gas control valve 10 is reduced. In addition, the hot air temperature control unit 80 compares the temperature detection value of the hot air temperature detector 8 provided between the crusher 7 and the bag filter 9 with a preset temperature set value to determine the atmospheric air control valve 15. Control the opening degree.

That is, in the related art, the flow rate of hot air is controlled by the hot air flow rate control unit 70 and the temperature is controlled by the hot air temperature control unit 80 at the same time, depending on the temperature of the exhaust gas, the temperature of the atmospheric air, the crusher pulverized coal production amount, and the like. By varying the mixing ratio of the exhaust gas and atmospheric air, the flow rate and temperature of the hot air were controlled.

In general, the total amount of exhaust gas discharged from the blast furnace hot stove 11 is approximately 135.000 nm 3 / h, and the total amount of exhaust gas available for pulverized coal is approximately 60,000 nm 3 / h. The remainder is thus discharged into the atmosphere through the chimney 12. When the exhaust gas is introduced at about 60,000 nm 3 / h, the production of pulverized coal varies depending on season, about 50 ton / h in summer, and about 30 ton / h in winter. It uses a mixture of atmospheric air to control the temperature of the exhaust gas. This is because the temperature of atmospheric air varies with each season.

In winter, when the amount of coal supplied to the crusher 7 is 30 ton / h or more, the hot air temperature control unit 80 increases the amount of exhaust gas and decreases atmospheric air. However, due to the limitation of the amount of exhaust gas supplied, the hot air flow rate in proportion to the amount of coal cannot be secured, so that the outlet temperature of the crusher 7 may drop below 80 ° C. When the exit temperature of the shredder 7 drops, the shredability of the pulverized coal is deteriorated and the amount of water is increased so that the pulverized coal is not smoothly transported to the upper portion of the bag filter 9, so that the outlet of the shredder 7 is blocked by the pulverized coal. There is this.

In addition, the exhaust gas is introduced in the winter season, the air heater 1 is activated to increase the amount of atmospheric air, which reduces the amount of exhaust gas and increases the amount of atmospheric air, thereby increasing the oxygen concentration in the hot air. The probability of a fire occurring in the crusher 7 becomes high.

The present invention is to solve the above conventional problems, the purpose is to reduce the temperature of the shredder outlet and the oxygen concentration in the hot air regardless of the change in the temperature of the atmosphere according to the season, discharged from the bag filter instead of atmospheric air It is to provide a hot air control device in the pulverized coal manufacturing equipment for recovering the discharge gas to be supplied to the pulverized coal manufacturing equipment.

1 is a schematic configuration diagram of a hot air control device in a conventional pulverized coal production facility.

Figure 2 is a schematic configuration diagram of a hot air control device in the pulverized coal production facility according to the present invention.

3 is an operation timing diagram of a conventional hot air control device.

4 is a timing diagram of a hot air control device in the pulverized coal production facility according to the present invention.

* Explanation of symbols for main parts of drawings *

6: feeder 10: exhaust gas control valve

9: Bag filter 15: Atmospheric air control valve

20L: exhaust gas recovery line 21: dryer

22: exhaust gas temperature detector 23: exhaust gas temperature control valve

25: exhaust gas flow control valve 30: exhaust gas temperature control unit

40: supply of coal supply amount 50: hot air flow rate calculation unit

60: hot air flow rate detection unit 70: hot air flow rate control unit

80: hot air temperature control unit

The apparatus according to the present invention includes a crusher for pulverizing coal to produce pulverized coal, a bag filter connected to the crusher to collect pulverized coal transported by hot air and to discharge hot air to a gas outlet, between the crusher and the bag filter. In a pulverized coal production facility having a temperature detector installed to detect a temperature at the outlet of the shredder,

An exhaust gas recovery line for transferring the exhaust gas of the bag filter to the front end of the crusher by a pipe connecting the gas outlet of the bag filter to the front of the crusher;

A dryer installed in the bag filter exhaust gas recovery line to remove moisture of the exhaust gas discharged from the bag filter;

An exhaust gas temperature detector installed in the bag filter exhaust gas recovery line and detecting a temperature of the exhaust gas passing through the dryer;

An exhaust gas temperature control valve installed in a pipe inferred from the bag filter exhaust gas blowing line between the dryer and the exhaust gas temperature detector to adjust the amount of air supplied to the bag filter exhaust gas blowing line;

An exhaust gas temperature control unit controlling an opening degree of the exhaust gas temperature control valve so that the exhaust gas temperature detection value of the exhaust gas temperature detector is equal to a preset exhaust gas temperature set value;

An exhaust gas flow control valve installed at a rear end of the exhaust gas temperature detector in the bag filter exhaust gas injection line and controlling a supply amount of the exhaust gas supplied to the front of the crusher;

A hot air flow rate detection unit generating a switching signal when a flow rate detection value of the hot air flow rate detector is greater than a preset flow rate setting value; And

A hot wind temperature controller configured to adjust an opening degree of the exhaust gas flow control valve so that the temperature detection value of the input temperature detector is equal to a preset temperature set value when the switching signal is generated in the hot air flow rate detection unit;

Characterized in having a.

Hereinafter, the hot air control device in the pulverized coal production facility according to the present invention will be described in detail with reference to the accompanying drawings. In the referenced drawings of 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 hot air control device in a pulverized coal production facility according to the present invention. As shown in FIG. 2, the apparatus of the present invention is a pipe connecting the gas outlet of the bag filter 9 and the front of the crusher 7. The discharge gas recovery line 20L for transferring the exhaust gas of the bag filter 9 to the front of the shredder 7 and the bag filter exhaust gas recovery line 20L are discharged from the bag filter 9. A dryer 21 for removing moisture of the discharged gas, and an exhaust gas temperature detector 22 installed in the bag filter exhaust gas recovery line 20L and detecting a temperature of the exhaust gas passing through the dryer 21; , Installed in a pipe inferred from the bag filter exhaust gas blowing line 20L between the dryer 21 and the exhaust gas temperature detector 22 to adjust the amount of atmospheric air supplied to the bag filter exhaust gas blowing line 20L. Exhaust gas temperature control valve (2 3) and an exhaust gas temperature control unit 30 for controlling the opening degree of the exhaust gas temperature control valve 23 such that the exhaust gas temperature detection value of the exhaust gas temperature detector 22 is equal to a preset exhaust gas temperature set value. And an exhaust gas flow rate control valve 25 installed at a rear end of the exhaust gas temperature detector 22 in the bag filter exhaust gas injection line 20L and controlling a supply amount of the exhaust gas supplied to the front of the crusher 7. When the flow rate detection value of the hot air flow rate detector 3 is greater than a preset flow rate setting value, the hot air flow rate detection unit 60 generating a switching signal, and the switching signal is generated by the hot air flow rate detection unit 60. It includes a hot air temperature control unit 80 for adjusting the opening degree of the exhaust gas flow control valve 25 so that the input temperature detection value of the temperature detector 8 is equal to the preset temperature set value.

4 is a timing diagram of a hot air control device in the pulverized coal production facility according to the present invention, and the operation of the present invention according to the above-described configuration will be described with reference to FIG.

First, referring to FIG. 2, hot air is supplied to the crusher 5 to dry the pulverized coal and then transferred to the bag filter 9. The hot air conveyed together with the pulverized coal to the bag filter 9 is discharged to the gas outlet of the bag filter 9.

The hot air discharged to the gas discharge port of the bag filter 9 is recovered through the bag filter discharge gas recovery line 20L and supplied to the pulverized coal manufacturing facility by replacing the atmospheric air sucked through the atmospheric air control valve 15. do. The exhaust gas discharged from the bag filter 9 to the bag filter discharge gas recovery line 20L is removed from the dryer 21. The exhaust gas temperature detector 22 detects a temperature of the exhaust gas from which moisture is removed by the dryer 21 and outputs the temperature to the exhaust gas temperature control unit 30. The exhaust gas temperature control unit 30 calculates the exhaust gas temperature detection value of the exhaust gas temperature detector 22 and a preset exhaust gas temperature set value, and according to the calculated value, the exhaust gas temperature control valve 23. The temperature of the exhaust gas is controlled by adjusting the opening degree of the gas. The temperature of the exhaust gas is typically maintained at 30 ° C, the opening degree of the exhaust gas temperature control valve 23 is increased if the exhaust gas temperature detection value is 30 ° C or more, and the exhaust gas temperature detection value is 30 ° C Below, the opening degree of the exhaust gas temperature control valve 23 is reduced as shown in FIG.

In the state in which the pulverized coal production equipment is stopped, the coal feed amount setter 40 sets the coal feed amount set value to a minimum value (13 ton / h) and outputs it to the feeder 6 and the hot air flow rate calculation unit 50. The minimum feed amount set value is converted into a minimum hot air flow rate setting value corresponding to the flow rate curve in the hot air flow rate calculation unit 50 and output to the hot air flow rate detection unit 60 and the hot air flow rate control unit 70.

When the pulverized coal production facility is started, the inhaler 9 is started. When the inhaler 9 is activated, the atmospheric air control valve 15 is opened and a predetermined number of air air is sucked in, and the exhaust gas of the hot air passage 11 is sucked through the exhaust gas control valve 10. . The hot air sucked in this way is supplied to the crusher 7, wherein the hot air flow rate detector 3 in front of the crusher 7 detects the flow rate of the hot air as a hot air flow rate detection value to detect the hot air flow rate detection unit 60 and The hot air flow rate control unit 70 transmits.

The hot air flow rate control unit 70 inputs a hot air flow rate detection value of the hot air flow rate detector 3 and a minimum hot air flow rate setting value of the hot air flow rate detection unit 60 to calculate two values to calculate the exhaust gas control valve ( By controlling the opening degree of 10), the flow rate of the exhaust gas supplied to the pulverized coal production facility is controlled.

In addition, when the hot air flow rate detection value of the hot air flow rate detector 3 and the minimum hot air flow rate setting value of the hot air flow rate detection unit 60 are input to the hot air flow rate detection unit 60, the hot air flow rate detection unit 60 is input. The switching signal is generated when the hot air flow rate detection value becomes larger than the minimum hot air flow rate setting value.

The hot air temperature controller 80 receives a flow temperature temperature detection value of the crusher outlet temperature detector 8 and calculates a flow rate temperature setting value to output a signal for controlling the valve opening degree. The hot air temperature control unit 80 outputs a control signal to the exhaust gas flow control valve 25 when a switching signal is generated in the hot air flow rate detection unit 60, and the switching signal is output from the hot air flow rate detection unit 60. If not generated, a control signal is output to the atmospheric air control valve 15. That is, when the hot air flow rate detection value of the hot air flow rate detector 3 corresponds to the minimum feed amount set value of the feed amount setting portion 40, the atmospheric air control valve 15 as shown in FIG. It is closed and the exhaust gas flow control valve 25 is opened so that the exhaust gas is sucked into the pulverized coal production facility instead of the atmospheric air.

Therefore, the pulverized coal production facility uses the bag filter exhaust gas instead of atmospheric air, thereby lowering the oxygen concentration in the sucked hot air gas to 10% or less. In addition, instead of igniting the air heater 8 to raise the hot air to a high temperature, by increasing the exhaust gas temperature setting value of the exhaust gas temperature control unit 30, the exhaust gas temperature of the bag filter is increased, the change according to the external environment Compensate for the temperature of the hot air.

The present invention recovers the exhaust gas discharged from the bag filter, and supplies the recovered exhaust gas to the pulverized coal production facility instead of atmospheric air to adjust the flow rate of the hot air, thereby reducing the oxygen concentration in the hot air to reduce the fire of the crusher and the bag filter ( Has an excellent effect of enabling a more stable operation of the plant, which is prevented in advance.

Claims (2)

A crusher for pulverizing coal to produce pulverized coal, a bag filter connected to the crusher to collect pulverized coal transported by hot air and dissipate hot air to a gas discharge port, and installed between the crusher and the bag filter and at the temperature of the crusher outlet. In the pulverized coal production equipment having a temperature detector for detecting A discharge gas recovery line 20L configured to transfer the discharge gas of the bag filter to the front of the crusher by a pipe connecting the gas discharge port of the bag filter to the front of the crusher; A dryer 21 installed in the bag filter exhaust gas recovery line 20L to remove moisture of the exhaust gas discharged from the bag filter; An exhaust gas temperature detector 22 installed in the bag filter exhaust gas recovery line 20L and detecting a temperature of the exhaust gas passing through the dryer 21; It is installed in the pipe inferred from the bag filter exhaust gas blowing line 20L between the dryer 21 and the exhaust gas temperature detector 22 to adjust the amount of air supplied to the bag filter exhaust gas blowing line 20L. Exhaust gas temperature control valve 23; An exhaust gas temperature control unit 30 for controlling the opening degree of the exhaust gas temperature control valve 23 such that the exhaust gas temperature detection value of the exhaust gas temperature detector 22 is equal to a preset exhaust gas temperature set value; An exhaust gas flow control valve (25) installed at a rear end of the exhaust gas temperature detector (22) in the bag filter exhaust gas injection line (20L) to adjust a supply amount of the exhaust gas supplied to the front of the crusher; A hot air flow rate detection unit (60) generating a switching signal when a flow rate detection value of the hot air flow rate detector is larger than a preset flow rate setting value; And When the switching signal is generated in the hot air flow rate detection unit 60, a hot air temperature control unit for adjusting the opening degree of the exhaust gas flow control valve 25 so that the input temperature detection value of the temperature detector and the preset temperature set value are the same ( 80); Hot air control device in the pulverized coal manufacturing equipment, characterized in that provided with. The method of claim 1, An exhaust gas control valve (10) installed in the supply pipe of the exhaust gas supplied to the crusher to adjust the supply amount of the exhaust gas; An air air control valve (15) installed in a supply pipe of air air supplied to the crusher to adjust the supply amount of air air; A coal supply amount setting unit 40 for arbitrarily setting a coal supply amount of coal charged into the crusher; A hot air flow rate calculation unit (50) for receiving the feed amount of fuel set value of the feed rate setting unit (40) and calculating the flow rate setting value of the corresponding hot wind; And The flow rate of the hot air flow is controlled by adjusting the opening degree of the exhaust gas control valve so that the flow rate detection value of the hot air flow rate detector and the flow rate setting value of the hot air flow rate calculation unit 50 are input. Hot air flow control unit 70; Hot air control device in the pulverized coal manufacturing equipment characterized in that it further comprises.