KR100891822B1 - Method for temperature control upon a up the heat load of stave blast furnace - Google Patents

Abstract

One aspect of the present invention relates to a temperature control method when a heat load rises in a stave blast furnace. In particular, when the heat load rises in a stave blast furnace, the temperature is increased to stabilize the gas flow in the furnace and to stabilize the heat load in a locally generated furnace. To control.

In the temperature control method of the stave blast furnace heat load rise of the present invention, if the stave temperature is equal to or greater than the first set temperature, the drain temperature controller opens the freezer cooling water flow control valve and closes the stave cooling water flow control valve to close the stave drainage temperature. A first step of controlling; A second step in which the pulverized coal injection control means switches the pulverized coal injection mode into the purge mode, wherein the pulverized coal injection mode at the lower part of the zone where the stave cooling water flow rate control valve at which the stave temperature is increased is located; A third step of closing the hot air flow rate control valve installed in the blower pipe of the tuyere that has been switched to the purge mode at a predetermined ratio; A fourth step of opening, by the motor, the hot air flow rate control valve at a predetermined ratio when the stave temperature is lower than or equal to the second set temperature lower than the first set temperature; A fifth step in which the pulverized coal injection control means switches the purge mode to a blown mode; And a sixth step of controlling the stave drainage temperature by opening the stave cooling water flow control valve and closing the freezer cooling water flow control valve by the drain temperature controller.

Stave Coolant Flow Control Valve, Refrigerator Coolant Flow Control Valve, Drain Temperature Controller, Flow Controller

Description

Method for temperature control upon a up the heat load of stave blast furnace}

One aspect of the present invention relates to a temperature control method when a heat load rises in a stave blast furnace. In particular, when the heat load rises in a stave blast furnace, the temperature is increased to stabilize the gas flow in the furnace and to stabilize the heat load in a locally generated furnace. To control.

In blast furnace operations, aging is represented by the ventilation, aging and load dropping conditions in the furnace, and the distribution of fuel and raw materials in the furnace is closely related to these factors.

The distribution of the blast furnace shows the form in which fuel or raw materials dropped through the swing chute 8 accumulates in the blast furnace, and the distribution of the blast furnace is divided into radial and circumferential directions.

Currently, a bell-less type topless charging device is adopted as a charging device for blast furnace fuel or raw materials. The distribution of fuel or raw materials in the radial direction can be adjusted by adjusting the tilting angle of the chute. There is a characteristic.

In particular, the goal of the bellless type blast furnace load distribution adjustment is to improve productivity by improving air permeability in the furnace, to reduce fuel costs by improving gas utilization in the furnace, to extend furnace life by suppressing furnace heat load, to improve core aeration and liquid permeability. This is to improve outlet discharge, prolong the life of the side wall of the furnace, and prevent accidents such as slip, hanging, air deflection, cold cooling, and core pollution.

1 is a charging device for a fuel and a raw material of a conventional blast furnace. As shown in FIG. 1, the charging belt conveyor 51 serves to transfer the raw material of coke 53 and iron ore 52 as fuel to the top hopper 42. The fuel and raw material incorporated into the top hopper are the MCG (Material Control Gate) 43, which controls the feed rate at the time of charging the fuel and raw material, and serves to finally spray the contents from the turning chute 8 into the furnace. Do it. In addition, when the fuel chute and the raw material are introduced, the turning chute 8 is rotated to control a uniform distribution in the circumferential direction.

Looking at the distribution of fuel and raw materials in the blast furnace 1, first, coke is charged to form a coke terrace and an inclination angle. After this, an ore is charged, which collides the ore with the terrorist tip to break up the coke layer by kinetic energy and form a mixed layer (coke + ore) to adjust the coke ratio (O / C) to the ore. Even under the air, it forms a distribution with excellent breathability and gas utilization.

2 is a pulverized coal injection state and a gas distribution diagram of a conventional blast furnace, and FIG. 3 is a detailed view of portion A of FIG. 2. As shown in Figure 2 and 3, the lower part of the blast furnace (1) is provided with a blowhole (5) consisting of 30 to 38 per circumferential direction, the blower pipe (60) coupled blow pipe (not shown) (60) Through the hot air is blown. At this time, it is possible to confirm the flow rate through the blowing flow meter 62 in the blowing branch pipe 60, and the hot air flow rate adjusting valve 61 made of ceramic is provided to individually control the blowing flow rate.

In the above process, the charging of coke as a main fuel and pulverized coal as an auxiliary fuel are carried out at high pressure through a blow pipe for blowing hot air. Looking at the process, the finely crushed coal through the pulverized coal manufacturing equipment (not shown), the distribution valve 30 is passed through the transfer line 32 by the pulverized coal injection valve 31, the blowing branch pipe (60) Through the pulverized coal blowing lance 33 installed in the blow pipe of the blowing blower 5 is composed of 30 to 38 pieces per circumferential direction.

At this time, the pulverized coal blown together with the hot air is passed through the coke slit layer of the softening fusion zone where the softening and melting of the charges is initiated through the combustion reaction, followed by the reduction process with the charges. Exit through wealth

When the fuel chute and the raw material are introduced, the chute chute 8 is rotated to control a uniform distribution in the circumferential direction. In the lower part of the chute chute 8, the blast furnace 1 is used to control the flow of gas generated during the operation of the blast furnace 1. In the direction of the furnace wall part, the center flow 50, the intermediate flow 51, and the periphery 52 are formed.

4 is a stave installation diagram and a detailed cross-sectional view of a conventional stave blast furnace. As shown in FIG. 4, in the blast furnace 1, pulverized coal and coke are reacted with oxygen to generate high temperature heat, and the generated gas is involved in melting and reducing the charges. The stave 10 cooling method is adopted as a method for protecting the blast furnace shell 2 by such a gas. Looking at the structure of the stave 10, a cooling flow path is formed in the rectangular inner cylinder 10, the water supply line 11 and the drainage line 12 is formed, the temperature sensor 13 inside the blast furnace shell (2) It is fixed to and installed in the sealing agent (3) to block the gas flow path.

The stave 10 is connected in a multi-stage manner, and the coolant drained from the lower part is connected to the upper stave through the connection pipe 14 to supply water, which is drained from the top stave 10.

5 is a view for explaining conventional stave cooling. As shown in FIG. 5, six sub discharge pipes 20b are separated from the main discharge pipe 20a to which the stave pump 20 is connected by dividing into six zones in the circumferential direction of the blast furnace 1. Each sub discharge tube 20b is provided with a manual valve 21 for adjusting the flow rate. The sub discharge pipe 20b is divided into four branch pipes for each zone, and is supplied to the stave 10, and integrated into one through the drain line 20c at the uppermost level. A pipe connected to each stage stave 10 is coupled to the sub discharge pipe 20b and cooled through the water supply line 11 and the drain line 12. In addition, a flowmeter 22 and a drain thermometer 23 are provided at the top drain line 20c.

Looking at the conventional temperature control method in the blast furnace, if the ore is distributed too much in the furnace wall by controlling the distribution of fuel and raw materials of the blast furnace, the ambient flow is suppressed and the deposits grow excessively due to the overcooling of the furnace wall portion Load instability, as well as poor breathability in the furnace, can lead to yellowing instability. On the contrary, if too much ore is distributed in the central portion, the gas flow to the center portion is suppressed and the gas flow to the furnace wall is activated, causing the heat load of the stave 10 and the temperature of the stave 10 to rise rapidly. do.

Recent blast furnace operations cause fluctuations in the gas flow in the furnace due to unstable aeration of gases in the furnace due to lower costs of lower fuel and raw materials due to cost savings.

This sudden fluctuation of the gas stream raises the stave heat load, thereby replenishing the fuel due to energy loss in the furnace, leading to an increase in fuel costs. In addition, when the stave temperature rises, the wear rate due to the charge drop decreases rapidly, thereby shortening the life of the furnace.

In order to prevent this, conventionally, the gas flow rate is improved by lowering the air flow amount to stabilize the gas flow and lowering the ore / coke in the charge.

In addition, in order to prevent damage to the stave, the branch pipe main manual valve 21 of the corresponding zone is additionally opened to secure a flow rate or the stave pump 20 is additionally operated.

However, this operation method had the following problems.

First, because manual operation is performed when the stave heat load rises, it is not possible to cope quickly and prevent the breakage of the stave due to the heat load rise, and fuel costs increase because the fuel must be replenished with energy loss in the furnace due to the heat load rise. .

Second, when the stave temperature rises, the wear rate due to the drop of the charge rapidly increases, shortening the life of the furnace.

Third, production cuts, such as wind blasts, are inevitable due to failure to stabilize local fluctuations of gas in the furnace at an early stage.

One aspect of the present invention is to control the temperature in order to stabilize the gas flow in the furnace and stabilize the heat load in the locally generated furnace by the gas flow control and cooling improvement when the heat load due to gas drift in the stave blast furnace rises It is an object to provide a method.

One aspect of the invention, the stave cooling water flow rate control valve connected between the stave blast furnace feed line and the stave pump; A refrigerator cooling water flow rate control valve connected between the water supply line and the refrigerator; A drainage temperature controller controlling the drainage temperature by opening the refrigerator coolant flow rate control valve; And a flow controller controlling the water supply flow rate by closing the stave cooling water flow rate adjusting valve.

According to another aspect of the present invention, when the stave temperature is equal to or greater than the first set temperature, the drain temperature controller may control the stave drainage temperature by opening the freezer cooling water flow control valve and closing the stave cooling water flow control valve. step; A second step in which the pulverized coal injection control means switches the pulverized coal injection mode into the purge mode, wherein the pulverized coal injection mode at the lower part of the zone where the stave cooling water flow rate control valve at which the stave temperature is increased is located; A third step of closing the hot air flow rate control valve installed in the blower pipe of the tuyere that has been switched to the purge mode at a predetermined ratio; A fourth step of opening, by the motor, the hot air flow rate control valve at a predetermined ratio when the second set temperature at which the stave temperature is lower than the first set temperature is high; A fifth step in which the pulverized coal injection control means switches the purge mode to a blown mode; And a sixth step of controlling the stave drainage temperature by opening the stave cooling water flow regulating valve and closing the freezer cooling water flow regulating valve by the drain temperature controller.

One aspect of the present invention is to prevent the breakage of the stave by preventing rapid rise of the heat load by a rapid response to the rise of the stave heat load, and to save fuel by preventing energy loss in the furnace by premature stabilization of the heat load rise. To prevent fuel costs from rising.

Another aspect of the present invention can significantly extend the life of the furnace because it prevents the rise of the temperature to prevent abrasion due to the load drop to prevent stave thermal expansion and contraction to prevent cracking.

Another aspect of the present invention is to stop the blowing of the pulverized coal in the zone during the local drift of the gas flow in the furnace and to reduce the blow flow rate to prevent the rise of the heat load by the combustion pulverized coal, to suppress the rise of the stave temperature, and to locally increase the blowing flow rate By reducing the gas drift, it is possible to maintain a stable drop of fuel and raw materials, thereby reducing production costs by preventing production operations such as the prevention of wind blowing, and reducing costs.

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

FIG. 6 is a configuration diagram of a temperature control device at the time of raising the stave blast furnace heat load of the present invention, FIG. 7 is an explanatory view of the pulverized coal injection control of the present invention, and FIG. 8 is a flowchart of the temperature control method at the time of raising the stave blast furnace heat load of the present invention. to be.

As shown in FIG. 6, the temperature control device at the time of raising the heat load of the stave blast furnace 1 includes a stave cooling water flow rate control valve 72, a freezer cooling water flow rate control valve 71, a drainage temperature controller 77, and a flow rate controller. (76).

The stave coolant flow control valve 72 is connected between the water supply line 11 and the stave pump 20, and the freezer coolant flow control valve 71 is connected between the water supply line 11 and the refrigerator 70. It is. Then, the drainage temperature controller 77 controls the drainage temperature by opening the freezer cooling water flow control valve 71, and the flow controller 76 closes the stave cooling water flow control valve 72 to control the water supply flow rate. At this time, the drain temperature controller 77 may control the drain temperature to a predetermined temperature. In addition, the opening of the refrigerator cooling water flow control valve 71 and the closing of the stave cooling water flow control valve 72 may be performed step by step at a predetermined ratio. Hereinafter, these will be described in detail.

The main discharge pipe 20a is connected to the stave pump 20, and the main discharge pipe 20a is separated into sub discharge pipes 20b in six zones. The stave cooling water flow rate regulating valve 72 is provided in the sub discharge tube 20b in the six zones. The pipe 20d is connected to the rear end of the stave coolant flow rate control valve 72 from the refrigerator 70, and the freezer coolant flow rate control valve 71 is installed at the stop of the pipe 20d.

Then, the sub discharge pipe (20b) is divided into four branch pipes and supplied to the stave 10, is integrated into one through the drain line (20c) of the upper end and drained. The drain line 20c is provided with a flow meter 22 and a drain thermometer 23, and a drain temperature controller 77 and a drain flow meter 22 for controlling the drain temperature at a temperature detected by the drain thermometer 23. A flow rate controller 76 is provided for controlling the water supply flow rate with the flow rate detected through.

In addition, the blowing branch pipe 60 is provided with a hot air flow rate adjusting valve 61 for adjusting the flow rate of the air flow into the blast furnace, and control the pulverized coal injection so that the pulverized coal can be blown through the pit 5 to control the circumferential direction of the blast furnace The means 34 and the blowing flow rate confirmation window 42 are provided.

The temperature control method of the temperature control device at the time of rising the heat load of the stave blast furnace 1 has the following process. Here, the first set temperature and the second set temperature may be set to 80 ℃, 50 ℃, respectively.

First, when the stave thermometer detects the temperature of the stave 10 (S10), the drainage temperature controller 77 determines whether the temperature of the stave 10 is equal to or greater than the first set temperature (S20). If it is determined that the temperature of the stave 10 is equal to or greater than the first set temperature, the drainage temperature controller 77 opens the freezer cooling water flow control valve 71 and closes the stave cooling water flow control valve 72 to close the stave 10. Control the drainage temperature (S30). In this case, when the temperature of the stave 10 is greater than or equal to the first set temperature, the alarm unit (not shown) may be set to generate an alarm. Through the alarm generation of the alarm unit, the operator can know whether the temperature of the stave 10 is higher than the set temperature. In addition, when the stave cooling water flow control valve 72 is closed, only 50% is closed without being completely closed.

Thereafter, the pulverized coal injection control means (not shown) switches the pulverized coal injection mode of the tuyere 5 in the lower part of the zone where the stave cooling water flow control valve 72 at which the temperature of the stave 10 rises is located. (S40).

Subsequently, the motor closes the hot air flow rate control valve installed in the blower pipe of the tuyere 5 switched to the purge mode at a predetermined ratio (S50).

Thereafter, the drain temperature controller 77 determines whether the temperature of the stave 10 is lower than or equal to the second set temperature lower than the first set temperature (S60). When the temperature of the stave 10 is lower than or equal to the second set temperature, the motor (not shown) opens the hot air flow rate control valve at a predetermined ratio (S70). At this time, when the temperature of the stave 10 is less than or equal to the second set temperature, the alarm unit may be set to generate an alarm. Through the alarm generation of the alarm unit, the operator can know whether the temperature of the stave 10 is lower than the set temperature. When the temperature of the stave 10 is equal to or less than the second set temperature, the process in the case where the temperature of the stave 10 is equal to or greater than the first set temperature is reversed.

Thereafter, the pulverized coal blowing control means switches the purge mode to the blowing mode (S80).

Thereafter, the drain temperature controller 77 opens the stave cooling water flow control valve 72 and closes the freezer cooling water flow control valve 71 to control the drainage temperature of the stave 10 (S90).

The pulverized coal blowing stop and the blowing branch pipe hot air control during the above process cause the rise of the temperature of the stale when the pulverized coal in combustion flows into the furnace wall part by the gas drift and flows in contact with the stave. By closing the 50% of the hot air flow control valve, the air flow is lowered locally in the zone, thereby lowering the air blowing energy, thereby reducing local heat load by suppressing gas drift.

1 is a charging device for a fuel and a raw material of a conventional blast furnace.

2 is a pulverized coal injection state and a gas distribution diagram of a conventional blast furnace.

FIG. 3 is a detailed view of portion A of FIG. 2.

4 is a stave installation diagram and a detailed cross-sectional view of a conventional stave blast furnace.

5 is a view for explaining conventional stave cooling.

Figure 6 is a block diagram of a temperature control device at the time of stave blast furnace heat load rise of the present invention.

7 is an explanatory view of fine coal injection control of the present invention.

8 is a flowchart illustrating a temperature control method at the time of raising the stave blast furnace heat load according to the present invention.

            <Explanation of symbols for the main parts of the drawings>

5: windball 10: stave

20: stave pump 20a: main discharge pipe

20b: sub discharge tube 20c: stave drain line

20d: pipe 22: drain flow meter

23: drainage thermometer 34: pulverized coal blowing control means

42: air flow rate confirmation window 61: hot air flow control valve

70: refrigerator 76: flow controller

77: drainage temperature controller

Claims (6)

delete delete delete delete A first step of controlling the stave drainage temperature by opening the freezer cooling water flow control valve and closing the stave cooling water flow control valve when the stave temperature is equal to or greater than the first set temperature; A second step in which the pulverized coal injection control means switches the pulverized coal injection mode into the purge mode, wherein the pulverized coal injection mode at the lower part of the zone where the stave cooling water flow rate control valve at which the stave temperature is increased is located; A third step of closing the hot air flow rate control valve installed in the blower pipe of the tuyere that has been switched to the purge mode at a predetermined ratio; A fourth step of opening, by the motor, the hot air flow rate control valve at a predetermined ratio when the stave temperature is lower than or equal to the second set temperature lower than the first set temperature; A fifth step in which the pulverized coal injection control means switches the purge mode to a blown mode; And A sixth step of controlling the stave drainage temperature by opening the stave cooling water flow control valve and closing the freezer cooling water flow control valve; Temperature control method at the time of rising of the blast furnace heat load comprising a. The method of claim 5, And an alarm unit generating an alarm if the stave temperature is greater than or equal to the first set temperature or less than the second set temperature.

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