JP2005314771A - Blast furnace facility and method for charging raw material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blast furnace facility with which only gas flowing extremely near the furnace wall in the blast furnace body can independently be controlled, and the consumption of coke can be reduced and the utilizing ratio of the gas can be improved. <P>SOLUTION: The blast furnace body 1 and a cylindrical member 14 disposed along the outer peripheral part of the furnace opening hole 1a in a piling surface of raw materials at the furnace top 2 of the blast furnace body 1, are included and the raw materials are charged from the furnace opening hole 1a in a state in which the cylindrical member 14 is arranged. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a blast furnace facility capable of controlling gas flow in the vicinity of a furnace wall pole of a blast furnace body and a raw material charging method thereof.

  The blast furnace is a huge counter-current packed bed reaction vessel, and the maximum temperature of the furnace wall exceeds 1000 ° C., but a long life exceeding 20 years is required. The reason for being able to withstand long-term wear and thermal shock due to the material dropping in the furnace is that there is a furnace wall deposit layer formed by zinc and an alkali compound. However, if the furnace wall deposit layer is too thick, it will cause a decrease in the actual working volume in the furnace, destabilization of the material drop, and furnace cooling trouble due to endothermic reaction at the time of dropping. is important.

  As a method for controlling the thickness of the furnace wall deposit, gas distribution control in the furnace radial direction by charge distribution is generally performed. When using an inexpensive inferior raw material rich in zinc or alkali, it is necessary to secure a stronger furnace wall flow and suppress excessive growth of furnace wall deposits.

The strength of the gas flow in the furnace radial direction can be measured by the CO ₂ concentration in the gas (gas utilization rate η _CO ). Higher gas flow velocity is greater eta _CO for a short reaction time of the reducing gas decreases. As the strength index of the Rokaberyu takes the difference between the maximum eta _CO and furnace wall of eta _CO radial, Figure 5 shows the relationship between the zinc content in the domestic and foreign blast furnace. From this figure, it can be seen that when a raw material rich in zinc is used, a stronger furnace wall flow is directed to prevent excessive adhesion of zinc.

  When using inexpensive high zinc raw material, a strong furnace wall flow is essential, but the area occupied by the furnace wall is large, so the overall gas utilization rate is reduced, and the deposit layer thickness is reduced while reducing the reducing material ratio. In order to avoid the enlargement of the gas, it is necessary to make only the vicinity of the furnace wall pole a low gas utilization rate and to make the other regions have a high gas utilization rate. For this reason, conventionally, as shown in FIG. 6, when charging the raw material from the furnace port 22 of the blast furnace body 21, the coke having better air permeability than the ore is concentrated and charged near the furnace wall 23. As a result, the air permeability of the furnace wall is secured.

However, when such a method is adopted, it is not possible to independently control only the gas flow in the vicinity of the furnace wall, so the gas utilization rate of the entire blast furnace is lowered and the amount of coke to be used is increased. It is uneconomical. In addition, since the used coke becomes CO ₂ at the stage of being discharged outside the steelworks, an increase in the amount of coke used is also an environmental problem that directly leads to an increase in the amount of CO ₂ generated.

On the other hand, methods for controlling the charging of raw materials have been proposed for various purposes (Patent Documents 1, 2, etc.), but these techniques also independently control only the gas flow near the furnace wall. That is not taken into account.
JP 60-93287 A JP-A-6-279819

  The present invention has been made in view of such circumstances, and can independently control only the gas flow in the vicinity of the furnace wall pole of the blast furnace body, thereby reducing the amount of coke used and improving the gas utilization rate. It is an object of the present invention to provide a blast furnace facility capable of performing the above and a raw material charging method in such a blast furnace facility capable of such.

  In order to solve the above problems, the present invention comprises a blast furnace furnace body, and a cylindrical member disposed along a furnace port outer peripheral portion on a raw material charging deposition surface at the top of the blast furnace furnace body, and the cylinder Provided is a blast furnace facility in which a raw material is charged from the furnace port in a state where members are arranged.

  Further, the present invention is characterized in that a cylindrical member is disposed on the raw material charging and deposition surface at the top of the blast furnace body along the outer periphery of the furnace port, and in this state, the raw material is charged from the furnace port. A raw material charging method in a blast furnace facility is provided.

According to the present invention, the cylindrical member is disposed along the outer periphery of the furnace port on the raw material charging and deposition surface at the top of the furnace, and the raw material is charged from the furnace port in this state. Can be concentrated in the vicinity of the furnace wall pole between the cylindrical member and the furnace wall. Therefore, only the gas flow in the vicinity of the furnace wall pole can be controlled independently, the furnace wall flow can be secured stably, and the other portions can have a high gas utilization rate. The gas utilization rate of the entire blast furnace can be improved while preventing the adhesion of zinc or the like. Further, since coke is concentrated and charged only in the vicinity of the furnace wall pole between the cylindrical member and the furnace wall, the amount of coke used can be reduced, the hot metal cost can be reduced, and the generated CO ₂ can be reduced. Can be reduced.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a schematic view schematically showing the entire structure of a blast furnace facility according to an embodiment of the present invention. As shown in this figure, this blast furnace facility has a blast furnace furnace body 1, and this blast furnace furnace body 1 has a furnace top portion 2, a shaft portion 3, a furnace belly portion 4, and a furnace bottom portion 5 in order from above. And the charging device 6 is provided in the furnace top part 2 of the blast furnace furnace body 1, The raw material 7 which consists mainly of iron ore and coke from this charging device 6 into the blast furnace furnace body 1 via the furnace port 1a. Is inserted. A plurality of tuyere 8 for blowing hot air for generating an in-furnace reaction is provided in the furnace bottom 5 in a circular shape, and the tuyere 8 sends hot air sent from a hot air blower tube 9 to the blast furnace. Blow into the body 1. In the area blown from the tuyere 8, a raceway 11 is formed, which is a space formed by the coke being pushed away by the energy of the blast blowing from the tuyere 8. Hot water and slag generated by the in-furnace reaction are present as a hot metal layer and a slag layer in the hot water pool portion 12 present in the furnace bottom 5, and the hot metal and slag are periodically discharged from the spout 13.

  A cylindrical member 14 is disposed along the outer periphery of the furnace port 1a on the raw material charging and deposition surface 7a of the top 2 of the blast furnace body 1. The cylindrical member 14 is inserted from the furnace port 1a and inserted into the raw material deposition surface. And the furnace wall insertion part 15 is formed between the cylindrical member 14 and the furnace wall 1b. The width of the furnace wall charging portion 15 is preferably as narrow as possible, but in practice, considering the fall width of the charged raw material, the aging of the furnace port panel and the cylindrical member 14, the suppression of the raw material drop by the cylindrical member 14, etc. It is determined. Specifically, it is about 400-1500 mm.

In the blast furnace equipment configured as described above, iron ore and coke as raw materials are charged in a state where the cylindrical member 14 is arranged in this manner. When the coke is charged, it can be concentrated and supplied to the furnace wall charging portion 15 between the cylindrical member 14 and the furnace wall 1b. Since coke has better air permeability than iron ore, the furnace wall flow can be stably ensured by supplying coke in a concentrated manner in the vicinity of the furnace wall pole. For other parts, the gas utilization rate can be increased by reducing the amount of coke charged. Further, since coke can be supplied concentrated on the furnace wall portion, the amount of coke used can be reduced. Therefore, it is possible reducing agent ratio and the coke ratio reduces reduced, CO ₂ emissions and hot metal costs.

Next, in order to confirm the effect of the present invention, the results of experiments using a 1/15 scale model of a 4000 m ³ blast furnace will be described. FIG. 2 shows a schematic diagram of the experimental apparatus. (A) is a conventional type, and (b) is one using the cylindrical member of the present invention. The diameter of the furnace port of this model is 600 mm, and the distance between the cylindrical member and the furnace wall is exemplified as 60 mm. As shown in FIG. 2 (a), in the conventional type, coke is charged so as to concentrate coke having better air permeability than iron ore on the furnace wall, but it is concentrated in the vicinity of the furnace wall pole. It is difficult. On the other hand, as shown in FIG. 2B, in the present invention, coke can be concentrated in the vicinity of the furnace wall pole due to the presence of the cylindrical member. FIG. 3 shows the raw material deposition shape and the wind speed measurement result by a model experiment.

  FIGS. 3A and 3B show the measurement results of the deposited shape, where FIG. 3A shows the conventional one, and FIG. 3B shows the one using the cylindrical member of the present invention. In addition, as shown in these figures, in the case of using a cylindrical member, the amount of coke charged to the outside of the cylindrical member was set so as to have the same coke layer thickness as before. Here, the distance between the cylindrical member and the furnace wall is made as small as possible to 25 mm. As shown in these figures, the use of the cylindrical member of the present invention can reduce the amount of coke charged inside the cylinder due to the presence of the cylindrical member, and the total amount of coke charged is the conventional amount of (a). It was possible to reduce 20% compared to the case.

  On the other hand, (c) and (d) in FIG. 3 are the wind speed measurement results, (c) is the conventional one, and (d) is the one using the cylindrical member of the present invention. As shown in these figures, by using a cylindrical member, it is possible to suppress the gas flow inside the cylinder while maintaining the furnace wall gas flow equivalent to the conventional one, and to increase the gas utilization rate compared to the conventional one. You can see that

Examples of the present invention will be described below.
Here, an example in which the present invention is applied to a blast furnace facility having an internal volume of 4000 m ³ is shown. The blast furnace equipment has a coke ratio of 360 kg / t, a pulverized coal injection amount of 140 kg / t, and a reducing material ratio of 500 kg / t. In this blast furnace facility, if the amount of coke on the furnace wall is reduced for the purpose of improving the gas utilization rate and reducing the coke ratio, the zinc emission will decrease, resulting in an operational failure such as an unsatisfactory material drop or a rapid decrease after hot metal temperature. There was a trend.

A cylindrical member was installed in the blast furnace body of such a blast furnace facility as shown in FIG. The cylindrical member was installed at a position 10% from the furnace wall with the radius of the furnace port. FIG. 4 shows the operation transition before and after the installation of the cylindrical member. As shown in this figure, it was confirmed that the gas utilization rate was improved by about 2% after the installation of the cylindrical member, and the zinc discharge was maintained at the same level. Since the amount of coke inside the cylindrical member was reduced while maintaining the gas flow in the vicinity of the furnace wall pole, it is considered that the gas utilization rate was improved while maintaining the zinc discharge. Further, since the amount of coke to be charged was reduced, the coke ratio and the reducing material ratio were reduced, and the CO ₂ emission amount and the hot metal cost could be reduced.

The schematic diagram which shows the blast furnace equipment concerning this invention. The schematic diagram of the experimental apparatus used in order to confirm the effect of this invention. The figure which shows the experimental result with the apparatus of FIG. The figure which shows the effect in the Example of this invention. The figure which shows the relationship between the furnace wall gas flow and the amount of zinc in a raw material in the conventional blast furnace equipment. The schematic diagram which shows the raw material charging state in the conventional blast furnace equipment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Blast furnace body 1a ... Furnace 1b ... Furnace wall 2 ... Furnace top part 6 ... Charger 7 ... Raw material 14 ... Cylindrical member

Claims (2)

  A blast furnace furnace body, and a cylindrical member disposed along the outer periphery of the furnace mouth on the raw material charging and deposition surface at the top of the blast furnace furnace body, and the raw material is fed from the furnace mouth with the cylindrical member disposed. Blast furnace equipment characterized by being charged.   Raw material charging in a blast furnace facility characterized in that a cylindrical member is arranged along the outer periphery of the furnace port on the raw material charging and deposition surface at the top of the blast furnace body, and in this state, the raw material is charged from the furnace port. Method.

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