KR200291551Y1 - Ventilation temperature control device of blast furnace - Google Patents

Abstract

The present invention prevents rapid thermal deformation of the pulverized coal injection lance by injecting cooling water into the wind hole where the pulverized coal injection stop occurs, as well as lowering the combustion temperature at the tip of the blast furnace to reduce the flow of furnace and gas flow in the furnace. The present invention relates to an apparatus for controlling combustion of a tuyere in a blast furnace that can keep the furnace stable.

The present invention is equipped with an automatic valve and a high-pressure intake pump are installed in the waste water storage tank and the fresh water storage pipe to be introduced into the furnace, and a pressure reducing valve is connected to the water supply pipe to reduce the pressure to a certain pressure and maximize the flow rate. A flow rate detecting unit provided with an orifice and a flow transmitter at a rear end of the check valve for prevention; A pressure switch for detecting a pressure of the pipe, and a pressure detector installed with a pressure gauge; Water supply pipe which can control the constant flow rate of the pipe precisely and stop the injection of pulverized coal, water injection into the pulverized coal injection lance for each blowhole with the automatic valve; and, the supply water supply pipe through the pipe; A converter is provided for converting an analog signal of a flow rate and a pressure of a digital signal, and transmits such a control signal to a control computer, to a process computer, and to remotely open and close the automatic valve. It is provided with a switch operating panel; it provides a wind bulb combustion temperature control apparatus including a.

Description

Wind furnace combustion temperature control device of the furnace.

The present invention relates to a device for controlling the flue gas combustion temperature which rises sharply when the pulverized coal is blown into the set blast hole, when the pulverized coal is blown through the blast furnace blow holes. The present invention relates to an apparatus for controlling the combustion exit temperature of a blast furnace, which can prevent the rapid thermal deformation of the pulverized coal injection lance, as well as reduce the combustion temperature at the tip of the exit of the blast furnace so as to stably maintain the furnace heat and gas flow.

In general, large furnaces have about 34 vents in the circumferential direction, and small furnaces have about 25 vents. Most of the furnaces inject pulverized coal through the vents. Such pulverized coal acts as a heat source of the blast furnace, and when the pulverized coal injection pipe blown into each tuyere is damaged or the pulverized coal injection pipe is frequently blocked and the pulverized coal injection is stopped during operation, the tuyere is deformed from the pulverized coal injection lance installed therein. As a result, re-injection becomes impossible even if the cause of the pulverized coal injection is temporarily suspended, and the temperature of the tip of the tuyeres in the furnace is significantly higher than that of the tuyere where the pulverized coal is well blown.

If the pulverized coal injection is stopped in a particular tuyere while blowing a predetermined amount of pulverized coal (150 kg / T-P), the tuyere whose injection is stopped is about 450 ° C. higher than the tuyere into which the pulverized coal is blown.

In this way, if the tip of the tuyere is excessively high, it blocks the pores of COKE, which serves as a gas flow passage in the furnace, and obstructs the passage of gas (GAS), thereby making the charge drop of the site poor, thereby lowering the furnace productivity. In addition, since the heat source is not supplied to the corresponding portion, the circumferential balance of the furnace is broken, resulting in unstable operation of the furnace, thereby lowering productivity.

In addition, when the injection of pulverized coal is stopped in such a particular tuyere, measures to prevent deformation of the pulverized coal injection lance and to lower the combustion temperature of the tip of the tuyere are required. AIR) or nitrogen (N2), which is an inert gas, has been supplied.

However, the conventional method has the following problems.

The conventional method of purging air is somewhat effective in preventing deformation of the pulverized coal blowing lance, but does not lower the combustion temperature at the tip of the tuyere, and the injection of pulverized coal is stopped while oxygen in the air burns at the tip of the tuyere. Rather than a condition, the adverse effect of raising the combustion temperature of the tip of the tuyere.

In the case of nitrogen (N2), although the effect of preventing the deformation of the pulverized coal injection lance can be obtained more effectively than air, the combustion temperature is not increased as much as the injection of air in terms of lowering the combustion temperature at the tip end. It does not lower the combustion temperature at the tip. In addition, the conventional method of blowing air or nitrogen when the pulverized coal injection is stopped has been somewhat effective in terms of preventing deformation of the blowing lance, but the operating pressure of various pneumatic equipment used in the furnace equipment when a large amount of air is blown. The secondary problem that causes the malfunction of some equipment is reduced by lowering. In the case of using expensive nitrogen, there is a problem of increasing the molten iron manufacturing cost.

The present invention was devised to solve the above-mentioned problems, and prevents the deformation of the pulverized coal injection lance due to the sudden rise of the combustion temperature in the blast furnace where the pulverized coal injection in the blast furnace is stopped, as well as the thermal imbalance and the blockage of the gas flow passage. It is an object of the present invention to provide an apparatus for controlling the flue-ball combustion temperature of an improved smelting furnace so as to prevent a decrease in the amount of molten iron caused by the molten iron.

1 is a configuration diagram equipped with the furnace equipment combustion temperature control apparatus according to the present invention;

Figure 2 is a block diagram of a receiving annular tube equipped with the apparatus for controlling combustion combustion temperature according to the present invention;

Figure 3 is a schematic explanatory view showing the position of the tuyere made in the tuyere combustion temperature control apparatus according to the present invention;

Figure 4 is a side cross-sectional view showing the installation position around the tuyere equipped with a tuyere combustion temperature control apparatus according to the present invention.

* Description of the symbols for the main parts of the drawings *

10 ... Furnace 10a ... Fenggu

10b ... pulverized coal injection lance 10c ... hot air supply pipe

10d ... Hot Air Furnace 10e ... Cold Air Tube

10f ... blowers 10j ... blowpipes

11 ... wastewater reservoir 11a, 12a ... automatic valve

12 ... Freshwater Reservoirs 13 ... Water Blowing Pumps

14 ... water supply piping 14a, 15a ... hand valve

15,22 ... pressure switch

15a, 22a ... pressure gauge

16a ... reduce valve 17 ... solenoid valve

18 ... check valve 18a ... drain valve

19 ... orifice 19a ... flow transmitter

20 ... transducer 21 ... pneumatic control valve

25 ... control computer 26 ... process computer

28 ... control panel 30 ... receiving ring

The present invention as a technical means for achieving the above object, in the apparatus for controlling the flue-ball combustion temperature which rises sharply when the pulverized coal injection into the set tuyere is interrupted when the pulverized coal injection through the tuyere of the furnace,

An automatic valve and a water intake pump are installed in the waste water storage tank storing the water to be introduced into the furnace and the water supply pipe of the fresh water storage tank, and a pressure reducing valve for lowering the water pressure in the water supply pipe is connected; A flow rate detection unit having an orifice and a flow rate transmitter installed at a rear end of the check valve for preventing a back flow; A pressure switch for detecting a pressure of the water supply pipe, a pressure gauge, a pressure switch for comparing the front and rear pressures of the pressure reducing valve, and a pressure detector installed therein; Pneumatic control valve for precisely controlling the constant flow rate of the water supply pipe, and water supply pipe which can inject water into 34 air holes through the water supply annular pipe when the powdered coal injection stops, together with the automatic valve An incoming and outgoing classification pipe part connected to the controller; and a converter for converting an analog signal of a flow rate and a pressure of the feed water through the water supply pipe into a digital signal, and transmitting the control signal to the control computer. And a control panel having a monitor connected to the process computer for displaying on an image screen and equipped with an operation switch for remotely opening / closing the automatic valve. All.

Hereinafter, the configuration of the present invention with reference to the drawings in more detail.

As shown in FIG. 1, the wind ball combustion temperature control device 1 of the furnace according to the present invention has a flow rate detection unit 100, and the flow rate detection unit 100 includes a waste water storage tank 11 and a fresh water storage tank having a predetermined capacity. 12 is provided, the lower part of the water supply pipe 14 is provided with an automatic valve (11a) (12a) and the suction pump 13, the water supply piping connected to the suction pump 13 A manual valve 14a is connected along 14. Then, a pressure detecting unit 110 for detecting the pressure of the cooling water flowing in the water supply pipe 14 is provided, which is provided with a pressure gauge 15a for visually seeing the pressure, adjacent to the pressure switch ( a pressure switch (15) is provided and electrically connected to transmit the detected pressure to the control computer (25), and the pressure of the cooling water discharged from the intake pump (13) to a predetermined set pressure in the furnace (10). A reduce valve 16a for lowering is provided.

In addition, a check valve 18, an orifice 19 for detecting the amount of water flowing, and a flow rate transmitter l9a are connected to a rear end of the pressure reducing valve 16a to prevent a back flow of the fluid. Is mounted on the pipe to check the flow rate of the cooling water flowing in the pipe.

In addition, a pneumatic control valve 21 is installed to accurately control the amount of water flowing in the pipe along the water supply pipe 14, which is electrically connected to the analog-to-digital converter 20.

And, the receiving classifier pipe unit 120 is mounted, the receiving classifier pipe unit 120 is a pressure detector 22 and the repair manual valve 14a is connected to each other to the lower end of the pneumatic control valve 21, Along the water supply pipe 14, the receiving annular tube 30 having a constant diameter in the circumferential direction of the furnace is connected, in the receiving annular tube 30, as shown in FIG. (10a) Approximately 34 water supply branch pipes (31) extend in accordance with the quantity of water, and are connected to the outer pipe of the pulverized coal injection lance (10b) inserted into the tuyere (10a) as the automatic valve (34a).

The automatic valve 34a is electrically connected to the operation panel 28 so that an operator can remotely open and close the water, and when the automatic valve 34a is opened, water is supplied from the water supply pipe 31 to the pulverized coal injection lance 10b. Is supplied and supplied to the tuyere 10a.

On the other hand, the converter 20 for converting an analog signal representing a flow rate and pressure of the feed water into a digital signal is electrically connected to the control computer 25 to transmit a control signal and operate the furnace. Connected to the analytical process computer 26, the monitor 27 displays the pressure and flow conditions of the coolant on an image screen, and the control panel with electrical sequence and operation switches (not shown) during initial reception. ) Is electrically connected to the process computer 26.

In addition, as illustrated in FIG. 4, in the tuyere 10a, a thermocouple 33 continuously detecting the temperature of the tuyere 10a in a hot air supply pipe 10c having a pulverized coal blowing lance 10b mounted on one side thereof. The front end of the thermocouple 33 is extended to the inside of the tuyere 10a to transmit the temperature of the tuyere 10a on-line to the cab.

It describes the effect of the present invention configured as described above.

First, in the furnace 10, as shown in FIGS. 1 and 2, the wind sent from the blower 10f is supplied to the hot blast furnace 10d through the cold blast tube 10e and heated to about 1200 ° C. After the temperature is raised by the wind, it is allowed to enter the furnace 10 through the hot air pipe 10d ', the annular blowpipe 10j, and the 34 air vents 10a. At this time, pulverized coal used as fuel is blown into each tuyere 10a.

The tuyere combustion temperature control device 1 of the present invention can be confirmed that the temperature of any tuyere excessively rises by the temperature signal of the tuyere 10a provided by the thermocouple 33, so that the injection of pulverized coal is stopped. When the pulverized coal injection stop is confirmed as described above, the pulverized coal injection is initiated by selecting an import switch (not shown) of the operation panel 28 corresponding to the tuyere 10a.

At this time, when the operator selects the type of water to be blown out of the water stored in the fresh water storage tank 12 or the waste water storage tank 11 through a switch (not shown), one of the automatic valves 11a and 12a is selectively selected. It is opened and supplied to the receiving annular pipe 30 via the water supply pipe 14 by the operation of the receiving pump 13.

At this time, as shown in FIG. 2, water is immediately supplied to the pulverized coal injection lance 10b through opening of the automatic valve 34a provided in the water supply pipe 31 of the tuyere 10a where the pulverized coal injection is stopped. It is sprayed to the tuyere 10a. Therefore, such water normally lowers the temperature of the tuyere 10a on which the pulverized coal injection is stopped, thereby preventing deformation of the pulverized coal injection lance 10b, and prevents a sudden rise in the combustion temperature before the tufts 10a where the pulverized coal injection is stopped.

The present invention, as shown in FIG. 1 and FIG. 2, a separate small diameter water supply that can blow water from the receiving annular tube 30 having a constant diameter to the tuyere 10a of the furnace 10. The branch pipe 31 is taken out and connected to the pulverized coal injection lance 10b through an automatic valve 34a. In addition, the waste water storage tank 11 may be installed so that not only fresh water but also various waste water generated in the steel mill may be selectively supplied with two kinds of fresh water or waste water.

The pressure reducing valve 16a is installed in the water supply pipe 14 to supply a proper pressure in comparison with the pressure in the furnace 10 so as to maintain a pressure of 15 kg / cm 2 at 10 kg / cm 2, while the furnace 10 The check valve 18 is attached to the front of the pressure reducing valve 16a in order to prevent the blockage and breakage of the pipe due to the backflow of the gas and the melt in the furnace to the water supply pipe 14 due to the increase in the pressure in the tank.

When an accident cause such as a power failure occurs, even if the pressure of the water decreases, the blockage and breakage of the pipe due to the reverse flow of the gas and the melt in the furnace can be eliminated by the operation of the check valve 18.

In addition, the primary and secondary pressure gauges (15a, 22a) and pressure switches (15, 22), which are easy to see with the naked eye, are provided to compare the pressures, and to more accurately detect the amount of water supplied. (19), the flow rate transmitter 19a and the pneumatic control valve 21 for controlling the flow rate are provided so that the amount of water of 0.95 ± 0.05ton / lhr per blower is blown in.

This means that if excessive water enters a single vent, the heat balance of the coke layer inside the furnace is destroyed, resulting in a lowering of air permeability due to a lower temperature of the furnace, and an accident in which the lower part of the furnace is cooled down due to extreme deterioration of the furnace. In addition to the prevention, if too little water enters, there is a problem that the combustion temperature is not lowered as much as it is raised by stopping the pulverized coal injection. Therefore, the design can be made after the actual pulverized coal injection ratio of 130-150kg / tp is tested. It is.

Since the flow rate of the water supplied here is the most important factor, the thermocouple 33 continuously detects the temperature of the corresponding air outlet 10a in order to accurately monitor the amount of water in the air outlet 10a into which the water is blown. If the temperature of the tuyere 10a is maintained normally, the operator can stop the water supply by remotely closing the automatic valve 34a on the operation panel 28.

At this time, in order to more accurately adjust and monitor the amount of water injected, the water supply from the flow transmitter 19a is transferred to the control computer 25 and sent back to the furnace operation analysis process computer 26, and then the image operation monitoring. Accurate quantity can be supplied to the tuyere 10a by displaying whether the fine coal is blown or not and the number of blown shots for each of the thirty four tuyere on the monitor 27.

The water injection of the tuyere 10 using the tuyere combustion temperature control device 1 of the present invention as described above can be usefully used in the furnace 10 in addition to the deformation prevention and rust adjustment of the pulverized coal injection lance 10b as described above. have.

That is, in the furnace 10, in order to prevent fluctuations in the furnace situation due to changes in moisture in the wind coming from the atmosphere according to the change of the season and night and day, a certain amount of steam is blown into the furnace 10. Therefore, the use of a large amount of expensive steam is a factor to increase the cost of molten iron manufacturing is to inject inexpensive fresh water using the tuyegu combustion temperature control device (1) of the present invention.

As shown in FIG. 3, instead of the usual steam, three primary blow holes (40b, 40c, 40d) are selected as an equilateral triangle model, and three secondary blow holes (40f, 40g, 40h) are inverted triangles. By selecting and supplying water, it is possible to prevent the fluctuation of the yellowing while maintaining the circumferential balance of the furnace, and through such water supply, the amount of steam can be significantly reduced compared to before the present invention.

Hereinafter, the effects of the present invention will be summarized.

According to the present invention as described above, when the injection of the pulverized coal that has been blown into the blast furnace 10 is interrupted in whole or in part of the 34 tuyere 10a, each of the incoming ring annular tube 30 and the furnace 10 Water is blown in through the automatic valve 34a of the water supply pipe 31 provided in the tuyere 10a, so that the rapidly rising tue-tip combustion temperature is constant, and this process is the process computer 26 for the furnace operation analysis. The operator can observe and analyze closely through the image display screen of the monitor 27 connected to the.

Second, it is also possible to solve the problem that the powdered coal injection is impossible due to the local deformation of the powdered coal injection lance 10b due to the sudden change in combustion temperature, and to prevent the circumferential balance of the furnace from being broken by maintaining the thermal balance in the furnace 10. Thus, there is an effect that can prevent the problem of operation instability in advance.

Third, the water intake in the furnace is different depending on the humidity fluctuations of the season and night and day, and because the steam is expensive, it is supplied to the fresh water and waste water and supplied through the water supply pipe 14, the normal operation In the city, three primary blow holes are selected as an equilateral triangle model, and three secondary blow holes are selected as inverted triangles to supply water while maintaining the circumferential balance of the furnace. In addition, various kinds of wastes generated in steel mills are collected and removed from the blast furnace 10 to have a large number of advantages in terms of environmental conservation.

Claims (1)

In the apparatus for controlling the tuyere combustion temperature which rises sharply when the pulverized coal injection into the set tuyere is stopped when the pulverized coal injection into the blast furnace 10a of the blast furnace 10, Automatic valves 11a and 12a and a suction pump 13 are installed in the wastewater storage tank 11 storing the water to be introduced into the furnace 10 and the water supply pipe 14 of the freshwater storage tank 12, respectively. And a pressure reducing valve 16a for lowering the water pressure of the water supply pipe 14 is connected, and an orifice 19 and a flow rate transmitter 19a are installed at the rear end of the check valve 18 for preventing backflow. A flow rate detection unit 100; Pressure switch 15, pressure gauge 15a for pressure detection of the water supply pipe 14, pressure switch 22 for comparing the front and rear pressures of the pressure reducing valve 16a, and pressure gauge 22a A pressure detecting unit 110 installed; Equipped with a pneumatic control valve 21 for precisely controlling a constant flow rate of the water supply pipe 14, the water can be blown into the 34 vents (10a) through the receiving ring annular pipe 30 when the pulverized coal injection stops Supply branch pipe section 31 is connected to the pulverized coal injection lance 10b for each of the vent holes (10a) with the automatic valve 34a; and, the flow rate of the feed water through the water supply pipe 14 A converter 20 is provided for converting an analog signal of an overpressure to a digital signal, and transmits such a control signal to the control computer 25, which is connected to the process computer 26 to the image screen. And an operating panel (28) equipped with a monitor (27) to display and an operation switch for remotely opening and closing the automatic valve (34a).