KR20040017934A - Method for preventing channeling in blast furnace - Google Patents

Abstract

PURPOSE: A method for suppressing local channeling inside blast furnace is provided to prevent large scale channeling, slip and hanging by suppressing the channeling after detecting channeling partially generated by such causes as non-uniformity of charging material layer and increase of increase of low production in manufacturing of hot metal. CONSTITUTION: The method for suppressing local channeling inside blast furnace comprises first step of sensing flooding of the charging materials through a vibration sensing sensor installed at a probe installed at an upper part of the blast furnace to sense surface temperature of charging materials; second step of identifying vibration due to the flooding and vibration generated by drop impact of ore charged into the blast furnace from an upper side through a process computer, and calculating and operating the identified vibrations; and third step of operating a channeling suppression control system for giving an alarm and controlling blowing volume as a stepwise management according to vibration values by receiving magnitude of vibrations from the process computer.

Description

Method for preventing channeling in blast furnace

The present invention relates to a method for suppressing local extraction in a furnace, and more particularly, in the process of blowing a high-pressure hot air from the lower part of the charges in which the kankan is accumulated in the furnace to make the charges in the molten metal, unevenness of the charge layer, increase in low dose, etc. The present invention relates to a method for preventing large sized drawing, slipping, and hanging in advance by detecting the occurrence of partial picking due to the cause and suppressing it.

In general, as shown in the furnace operation conceptual diagram of FIG. 1, the operation method of the furnace 1 is hot air with a wind pressure of 3.8 to 4.1 kg / cm 2 and a flow rate of 6,000 to 6,300 Nm 3 / min sent from the blower 40. After the temperature is raised to about 1,200 ° C. in the furnace 12, the hot air line 13 and the tuyeres 14 of the furnace are pushed into the furnace, and in this case, coal dust and oxygen are blown in addition to the hot air for improved productivity and economic operation. 14) they are pushed together into the furnace.

In addition, from the upper part of the blast furnace 1, coke 24, which is a basis weight of fuel, and iron ore 25, which are raw materials, are imported to the top hopper 29, and the blast furnace 1 is sequentially turned through the turning chute 31. Charged into the inside, the charged iron ore (25) and coke (24) forms a layer, respectively, descends to the lower part of the furnace, the iron ore (25) and the coke (24) is filled with Kankan is filled (23) The hot air sent from the hot blast furnace 12 passes through the gasification to cause reduction and melting reaction to produce a molten iron 10, and the resulting molten iron 10 is gathered to the bottom of the blast furnace 1 and through the outlet. You will have a series of processes that are discharged to the outside.

The operation of the furnace is economical only when the lead and raw material distribution in the furnace is stabilized, the iron ore is reduced and melted under the condition that the gas flow is generally good, and the molten iron collected at the bottom of the furnace is discharged to the outside of the furnace. At the same time, productivity and blast furnace life can be extended.

However, as the operation rate of the blast furnace is gradually increased, the use rate of pulverized coal and low-grade iron ore made by pulverizing relatively inexpensive coal is replaced instead of the expensive fuel coke for the economic operation of the blast furnace. Due to the increase in the use experience of the furnace, the flue of the furnace body is unevenly damaged, and the contents of the furnace are attached to the furnace wall without locally falling, so that the contents of the contents are not evenly moved to the lower part of the furnace wall. A problem was encountered that hindered uniform gas flow.

As a result, the high temperature and high pressure gas blows through the charge layer and directly blows into the hearth 21. This results in high temperature (1,000 ° C.) and high pressure (about 3.5 kg / cm 2) furnace gas that does not undergo heat exchange. The 28 and the ore 26 are delivered directly to the top equipment to cause a fire, and the pressure in the hearth portion is increased momentarily to open the breather 11.

Therefore, the high temperature (1,000 ° C.) of the heat source is released into the atmosphere, and the furnace heat drops rapidly. The charged layer 23 in the furnace is disturbed, and the ore that is not reduced and melted is transferred to the furnace, and the melt hardens. Incident height is induced.

Here, for reference, withdrawal means that the charge filling layer is disturbed by the attachment light 27 or the like, in which gas passing through the charge filling layer in the blast furnace 1 is generated in the furnace wall, and the passage of the gas is confused and partially or multiplely. It means the phenomenon that the gas penetrates the charge layer as it is at a high temperature without exchanging heat with the charge instantaneously.

As a result of the traceback of the extraction, if the distribution of the ore 25 and the coke 24 in the circumferential direction and the radial direction in the furnace is non-uniform, a relatively light portion of the load of the charged material 23 pressed from above is pushed from the bottom. When the partial drop of the partial charge is temporarily stopped due to the rising gas pressure and there is a condition in which the gas easily falls out there, the load applied to the lower part is removed, causing partial blown of the gas and disturbing the charge passage by disturbing the charge layer. Was recognized.

This also further inhibits the escape of the gas, so the stopping range of the gas is further diffused and brings about extraction. This process is repeated several times, spreading repeatedly, and large blowout occurs.

Therefore, in-house phenomena, which result from different types of operation, lead, and raw material usage, do not appear consistently. Therefore, a prediction process suitable for the blast furnace is required.

Conventionally, as disclosed in Japanese Patent Laid-Open No. 62-270712 for the purpose of foreseeing the occurrence of slip and drawing and preventing the occurrence of the slip, the prediction is made based on the information obtained from the descent speed and the admiration of the in-vehicle charges. It was. In this case, the timing data from various furnace sensors are used to determine the authenticity data by comparing the data such as the dropping speed of the charge, the pressure loss in the furnace, the pressure loss of the shaft 20, the temperature, the temperature of the zone, and the gas utilization rate with the standard data. Later, inferring this by comparing with the contents in the knowledge base, and then deciding to confirm the prediction result is used, but, for example, in the nature of the data used, for example, the falling speed, the sounding (sounding) 30 per disturbance (The flow of gas, collision with the charges, etc.) has the disadvantage of not being able to increase the degree, and the slip, etc., is a problem related to the pressure balance in the furnace, so the pressure of the shaft is used as information, but the pressure movement of the shaft is slipped. Since the fluctuation range is not necessarily large at the time of occurrence, there is a problem that it is difficult to predict only by the pressure management of the shaft.

In addition, Japanese Patent Application Laid-open No. 58-71310 obtains a comparison between the pressure loss of the blast furnace and the load of the furnace load, and sets this condition in advance so that this ratio does not cause hanging, slipping, or drawing. It is known to be applied to the blast furnace blowing method. However, in this case, since it is difficult to increase the measurement accuracy of the furnace load, there is a limitation in that it is impossible to accurately predict slips or the like.

Furthermore, in Korean Patent Application No. 193-31777, it is essential to determine the possibility of incidence of blowout before and after the pressure difference (wind pressure-static pressure) for determining breathability based on the experience gained during the operation, about 1.8㎏ / ㎠. In general, the widespread situation is instantaneous, and the result is obtained through the analysis of data after it has already spread out and has already been taken. Therefore, it is only data analysis after the situation is closed. In addition, reliability of data due to errors such as a body pressure gauge and a thermometer may be poor.

The present invention has been made to solve the above problems, by detecting and reading the signs of the occurrence of the partial blown by the vibration detection sensor of the probe due to the non-uniformity of the inner layer of the furnace, the increase of low dose, etc. The purpose is to provide a method for preventing large blows, slips, and slumps in advance.

1 is a conceptual diagram showing a basic furnace operation;

2 is a schematic diagram illustrating occurrence of local extraction in a furnace;

3 is a perspective view showing a probe (probe) mounted with a vibration sensor according to the present invention,

4 is a graph showing the fluctuation of the furnace body pressure at the time of the occurrence of shaking, and the vibration due to profiling, and the rise of the temperature of the peak,

5 is a flow chart of the operation of the deodorant control system which is activated when the detection of the signs of drawing according to the invention,

Fig. 6 is a monitor screen displaying vibration caused by profiling when the extraction takes place according to the present invention.

<Description of Symbols for Main Parts of Drawings>

1: furnace 10: molten iron

11: open air breather 12: hot stove

13: hot air line 14: air opening

20: no-shaft shaft 21: local extraction

22: body pressure gauge 23: charge

24: coke layer 25: ore layer

26: blowing ore 27: attached light

28: top gas 29: top hopper

30: sounding 31: turning chute

32: probe 33: vibration sensor

In order to achieve the above object, the method of suppressing local extraction inside the furnace of the present invention includes: a vibration sensing unit provided in the probe 32 installed on the furnace 1 to sense the surface temperature of the charge 23. Detecting a flooding 26 of the charge 23 through a sensor 33; Two steps of distinguishing, calculating and calculating whether the vibration caused by the protruding 26 and the vibration generated by the drop impact of the ore charged from the upper part is provided through a provided process computer; And a step 3 of operating an intake control system for executing an alarm and controlling the air volume as a step by step according to the vibration value received from the vibration computer.

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

As shown in Figure 2, due to the increase in the use of low-grade iron ore and the increase in the blast furnace use experience, the ducts of the furnace body is unevenly damaged, and the contents are attached to the furnace body without dropping locally, and the charges to the lower part of the furnace body are lowered. 23 cannot be moved uniformly.

This causes a problem that the distribution of the charges 23 is partially disturbed and the uniform gas flow inside the furnace 1 is disturbed, and a large amount of rising gas 28 is charged at a time as a light load of the charges. Blowing out of the water 23 without heat exchange occurs.

Therefore, in the present invention, in order to detect this, as shown in Figure 3, in order to detect the surface temperature of the charge 23 in the upper part of the furnace 1 (60 degrees, 150 degrees, 240 degrees, 330 degrees) The process of attaching the vibration sensor 33 to the four probes 32 installed, and can distinguish the vibration caused by the floating 26 and the vibration caused by the charge or external vibration. A computer (not shown) is provided, and the process computer receives vibration values and performs calculations and calculations.

FIG. 4 is a data of the results of the extraction occurring on October 15, 1998 at POSCO Gwangyang Steel Works No. 2 furnace. When the signs of occurrence of local extraction 21 are detected and a large extraction occurs, the body pressure gauge 22, and It can be seen that the vibration value and the top temperature of the loading 26 are greatly changed. When the vibration value exceeds 12 mm / sec, it can be seen that the top temperature is maintained in an elevated state in connection with a large extraction. .

According to the present invention, as shown in Figure 5, by analyzing the vibration value on the basis of this, the extraction control control system is to be operated.

That is, after analyzing the magnitude of the vibration by the fretting 26, the program is operated in three steps as follows.

-next-

F1: 5 mm / sec was detected.

F2: When 8 mm / sec is detected.

F3: When it detects more than 10 mm / sec.

In the case of F1: It is used as a caution alert to alert operators that it is intermittent and feeble due to local aging of the aging.

In case of F2: Because the size of blown out is likely to spread, the blowout suppression control system is activated to control -400N㎥ / min from the current value at the same time as the alarm sound.

In case of F3: Since the overall risk of large blowout is large, the blowout suppression control system is activated to control -800N㎥ / min at the current air flow rate to prevent disturbance of the charges caused by large blowout, thus preventing cold intrusion. do.

Furthermore, FIG. 6 shows a process of transmitting the result of monitoring the step of vibration by the profiling when the extraction takes place according to the present invention to the operator through the process computer screen.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and by those skilled in the art to which the present invention pertains, Of course, various modifications and variations are possible within the scope of the claims to be described below.

According to the present invention, the blow out of the furnace operation causes a large-scale accident, so the focus has been on solving it from the past, but in the reality that the situation of the blow does not detect the progress locally, but only to rectify the accident after the blow has occurred. In order to prevent the occurrence of spreading by detecting local flotation which does not appear until now, and to operate the stepped extraction control system according to the size of the extraction, providing a method of preventing the extraction beforehand, The practical effect to prevent economic losses such as fire and cold accidents will be exhibited.

Claims (1)

Floating (26) of the charge (23) through the vibration sensor 33 provided in the probe 32, which is installed to detect the surface temperature of the charge (23) on the furnace (1) 1 step of detecting); Two steps of distinguishing, calculating and calculating whether the vibration caused by the protruding 26 and the vibration generated by the drop impact of the ore charged from the upper part is provided through a provided process computer; And a step 3 of operating a wind-up suppression control system which executes an alarm and blows air volume control as a step-by-step action based on the vibration value received from the process computer.