JPH08311512A - Method for measuring activity in core of blast furnace - Google Patents

Abstract

PURPOSE: To measure an activity of the whole furnace core at the time of stopping blasting in a blast furnace. CONSTITUTION: Metallic rods or metallic pipes 4 are inserted in from arbitrary tuyeres 5 at >=4 positions at the time of stopping the blasting in the blast furnace, and an insert velocity till reaching a prescribed insert depth, is measured. At this time, a range until negative acceleration to the insert direction from the tip part of the tuyere becomes the max., is defined as a raceway depth, and the raceway depth in the case of being at 1400 deg.C the premeasured temp. at the furnace core part is taken as a reference. When the receway depths in half number of the driven-in positions are lower than the reference receway depth, it is judged that the furnace core part is inactive. Otherwise, at the time of measuring the insert velocity, the insert velocity at the time of passing through the inner part in the furnace core at 2.5m deep position from the tip part of the tuyere is defined as a digging velocity and the digging velocity in the case of being at 1400 deg.C the premeasured temp. at the furnace core part is taken as a reference. When the digging velocity in half number of the driven-in positions are slower than the reference digging velocity, or when the min. digging velocity is <=0.7 times of the reference digging velocity, it is judged as that the furnace core part is inacitive.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the activity of a blast furnace when the blast furnace is at rest.

[0002]

2. Description of the Related Art A blast furnace for steelmaking can produce a large amount of pig iron and has a high thermal efficiency of 90%. Therefore, the mainstream of pig iron production is still maintained. However, since the blast furnace is a huge countercurrent moving bed, it has problems in productivity, production elasticity, etc., and further improvement of controllability is desired in order to secure a stable production amount and hot metal quality. ing. On the other hand, in the blast furnace, from the viewpoint of strengthening pig iron competitiveness, operations using cheap raw fuel and high pulverized coal ratio operations are being implemented.

Under the above-mentioned operation, pulverization of ore and coke increases, and the powder ratio in the lower part of the furnace including unburned char increases, making it difficult to secure the air permeability and liquid permeability of the furnace core. It is easy to become. Therefore, establishment of an effective method for measuring the core activity and activation technology is desired. As a conventional method for measuring the activity of the furnace core, the powder ratio measurement by the tuyere coke sampling and the coke hysteresis temperature measurement have been carried out. However, in this method, sample processing takes too much time and it takes more than one month to obtain the data, so there is a problem that timely action cannot be taken. Has been considered. As a simple method for measuring the activity of the furnace core, Japanese Unexamined Patent Publication (Kokai) No. 03-271308 discloses a method of estimating the coke powder ratio from the driving time of tuyere coke sampling when there is no wind. -21
Japanese Patent Laid-Open No. 0610/1993 discloses a method of estimating core air permeability from the insertion resistance value of a sonde inserted from a tuyere at the time of operation.
Japanese Patent Publication No. 5-255723 discloses a method of estimating the core activity from the pressure difference between the inside of the core and the tip of the tuyere measured by a sonde inserted from the tuyere during operation. On the other hand, in Japanese Patent Laid-Open No. 05-255723, the slag composition (Al ₂ O ₃ ) in the furnace core is measured to measure the blast furnace charging average slag composition (Al ₂
The method of estimating the core activity by comparing with O ₃ ) is disclosed in Japanese Patent Laid-Open No. 05-148519, in which the detection material in the hot metal discharged from the taphole is inserted into the detection material. A method of estimating the core activity from the residence time is disclosed.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the methods disclosed in Japanese Patent No. 71308, Japanese Patent Application Laid-Open No. 03-215610 and Japanese Patent Application Laid-Open No. 05-255723, the core activity can be estimated simply and quickly, but all of them are measured from one tuyere. Therefore, it may not be possible to evaluate the activity of the entire core. Further, JP-A 05-255723 and JP-A 05-255723
No. 148519 also has no idea of estimating the circumferential distribution of the core activity. In view of such problems of the prior art, the present invention provides information obtained when inserting a gold rod or a metal tube into a furnace core, that is, a raceway depth and a driving speed at a depth of 2.5 m. An object of the present invention is to solve the above problems by comparing the circumferential distribution with conventional values.

[0005]

That is, the present invention is as follows.
(1) When the blast furnace is in a breeze, the gold rod or metal pipe is driven from four or more arbitrary tuyere to measure the insertion speed until reaching the predetermined insertion depth. The range until the rate of change is less than or equal to -1 m / sec ² is defined as the raceway depth, and the raceway depth when the temperature of the furnace core part measured in advance is 1400 ° C. is used as a reference,
It is a method for measuring the activity of a blast furnace core, which is characterized in that the core is made inactive when the raceway depth of more than half of the driving-in points is below a reference raceway depth.

(2) When the blast furnace is in a blast, the gold rods or metal pipes are driven from four or more arbitrary tuyeres to measure the insertion speed until the predetermined insertion depth is reached. The insertion speed when passing inside the furnace core 2.5 m from the tip is defined as the excavation speed, and the excavation speed when the temperature of the furnace core portion measured in advance is 1400 ° C. is used as a reference, and more than half of the driving points are excavated. A method for measuring the activity of a blast furnace core, characterized in that the core is inactive when the speed is lower than the standard drilling speed or when the minimum drilling speed is 0.7 times or less than the standard drilling speed. is there.

[0007]

The present invention can be obtained by measuring the driving speed as shown in FIG. 2 when a gold rod or a metal pipe is driven from any tuyere at four or more places as shown in FIG. It is a technique to diagnose the circumferential distribution of the activity of the core based on the information obtained.

(1) According to the conventional measurement results, there is a relationship between the core temperature and the raceway depth as shown in FIG.
Here, the raceway depth is the rate of change of excavation speed minus -1.
It is defined as the driving insertion depth up to the range where it drops sharply below m / sec ² . If this relationship is used, the activity of the entire furnace core can be evaluated from the circumferential balance of the raceway depth.
Specifically, it is determined that the core is inactive when the raceway depth at which half or more of the driving is performed is shallower than the raceway depth of 1400 ° C., which is the reference core temperature.

(2) According to the conventional measurement result, there is a relationship as shown in FIG. 4 between the furnace core temperature and the driving speed at a depth of 2.5 m. Using this relationship, the activity of the entire furnace core can be evaluated from the circumferential balance of the driving speed at the depth of 2.5 m. Specifically, when the raceway temperature of the core temperature of 1400 ° C., which is the standard of the raceway depth of more than half of the driving, is lower than the driving speed of the raceway, or when the minimum excavation speed is 0.7 times or less of the standard, It is judged that the furnace core is inactive. By measuring the circumferential balance of the core excavation time in this way, the core activity can be accurately evaluated, and it becomes possible to deal with it in operation.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A concrete description will be given below based on the embodiments shown in the drawings.

(Example 1) When a large blast furnace with an internal volume of 4000 m ³ or more and 38 tuyeres has a blast, the 100 A metal pipes are inserted from 8 tuyeres into a depth of 3 m by the method shown in FIG. Then, the driving speed was measured. Specifically, the metal pipes 10 and 7 each having a length of 3 m are transferred from the tuyere 5 to the furnace core portion 6 by using the simple driving device 1 and the driving jig 2 that can be transported on the operating floor and have a small turning space. Typed in. The raceway depths of the 6 tuyeres were shallower than the raceway depth when the core temperature was 1400 ° C, so it was judged that the core was inactive and the action to activate the core was taken until the next breeze. At the same time as increasing the fuel ratio to 5 kg / t, the tuyere diameter was changed to increase the tuyere wind speed by 5%. At the time of the next blast, as a result of performing the driving of the metal pipes from the same 8 tuyere as the previous blast, as shown in Fig. 5, the raceway depths are all at the core temperature of 1400 ° C. It became longer than the raceway depth and the condition of the furnace core was improved.

(Embodiment 2) When a large blast furnace having an inner volume of 4000 m ³ or more and 38 tuyeres has no air, a metal pipe of 100 A is inserted from 8 tuyeres at a depth of 3 m by the method shown in FIG. It was driven into and the driving time was measured. Specifically, the metal pipes 10 and 7 each having a length of 3 m are transferred from the tuyere 5 to the furnace core portion 6 by using the simple driving device 1 and the driving jig 2 that can be transported on the operating floor and have a small turning space. Typed in. Since the driving speed of the tuyeres at 6 locations was lower than the driving speed when the core temperature was 1400 ° C, it was judged that the core was inactive,
As an action to activate the furnace core, the fuel ratio was increased by 10 kg / t and the blast moisture was increased by 10 g / Nm ³ until the next resting air. At the time of the next breeze, as a result of carrying out the driving of the metal pipe from the same eight tuyere as at the time of the previous breeze, as shown in Fig. 6,
The insertion speed is 3 m and the core speed is 140
It was higher than the driving speed at 0 ° C, and the condition of the furnace core was improved.

(Embodiment 3) When a large blast furnace having an internal volume of 4000 m ³ or more and 38 tuyeres has a blast, a 100A metal tube is inserted from 8 tuyeres at a depth of 3 m by the method as shown in FIG. Then, the driving speed was measured. Specifically, a simple driving device 1 that can be transported and has a small turning space.
And a metal jig 10 with a length of 3 m using the driving jig 2,
7 was driven into the furnace core 6 from the tuyere 5. The minimum value of the driving speed is 0. 0 when the core temperature is 1400 ° C.
Since it was 7 times or less, it was judged that the core was inactive, and the fuel ratio was set to 15 until the next breeze as an action for core activation.
kg / t increased. At the time of the next blast, as a result of performing the driving of the metal pipe from the same 8 tuyere as the time of the previous blast, as shown in Fig. 7, the minimum value of the driving speed is the driving at the core temperature of 1400 ° C. It became larger than the speed and the condition of the core was improved.

[0014]

According to the present invention, in order to evaluate the activity of the whole furnace core from the circumferential distribution of the activity of the core, the core activity measurement based on the conventional measurement result from one tuyere Compared with the method, the activity of the whole core can be evaluated quantitatively. Therefore, the action of activating the core can be performed accurately and in a timely manner, and the core can be efficiently activated.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a blast furnace tuyere showing a manner of driving a gold rod or a metal tube into a furnace core portion according to the present invention.

FIG. 2 is a graph showing the relationship between the driving depth and the driving speed when driving a gold rod or a metal tube into the furnace core.

FIG. 3 is a graph showing the relationship between core temperature and raceway depth.

FIG. 4 is a graph showing the relationship between core temperature and driving speed.

[Fig. 5] Rays before and after blast furnace activation operation (action)
It is a graph which shows sway depth.

FIG. 6 is a graph showing the implantation speed before and after the blast furnace activation operation (action).

FIG. 7 is a graph showing the implantation speed before and after the blast furnace activation operation (action).

[Explanation of symbols]

1: Portable simple pipe driving device 2: Pipe driving jig 3: Cap 4: Gold rod or metal tube 5: Tuyere 6: Furnace core 7: Gold rod or metal tube 8: Button 9: Raceway 10: Bird Nest

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[Procedure amendment]

[Submission date] June 5, 1995

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

FIG. ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 19, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

[0005]

That is, the present invention is as follows.
(1) When the blast furnace is in a blast, drive a gold rod or a metal tube from four or more arbitrary tuyere and measure the insertion speed until reaching the predetermined insertion depth. At that time, insert from the tuyere tip
The range until the negative acceleration becomes maximum with respect to the direction is defined as the raceway depth, and the raceway depth when the temperature of the furnace core measured in advance is 1400 ° C. is used as a reference, and half or more of the driving points are driven. -A method for measuring the activity of a blast furnace core, which is characterized in that the core is inactive when the sway depth is below a reference raceway depth.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

(1) According to the conventional measurement results, there is a relationship between the core temperature and the raceway depth as shown in FIG.
Here, the raceway depth is the insertion direction from the tuyere tip.
It is defined as the driving insertion depth to the range where the negative acceleration is maximum . If this relationship is used, the activity of the entire furnace core can be evaluated from the circumferential balance of the raceway depth.

Front page continuation (72) Inventor Masahiro Toki 1 Kimitsu, Kimitsu-shi, Chiba Inside Nippon Steel Corporation Kimitsu Steel Co., Ltd. Inside the Iron Plant Design Co., Ltd.

Claims (2)

[Claims] 1. When the blast furnace is in a blast, a gold rod or a metal tube is driven from four or more arbitrary tuyere to measure the insertion speed until reaching a predetermined insertion depth. At that time, the insertion is performed from the tip of the tuyere. The range until the rate of change in velocity becomes -1 m / sec ² or less is defined as the raceway depth, and the raceway depth when the temperature of the core portion previously measured is 1400 ° C is used as a reference, and the driving point is set. The method for measuring the activity of a blast furnace core is characterized in that the core is inactive when more than half of the trace depths are less than the standard raceway depth. 2. When the blast furnace is in a blast, a gold rod or a metal tube is driven from four or more arbitrary tuyere to measure the insertion speed until reaching a predetermined insertion depth. At that time, 2 from the tip of the tuyere is measured. The excavation speed was defined as the insertion speed when passing inside the core at a depth of 0.5 m, and the temperature of the core measured in advance was 1400 ° C.
Based on the excavation speed in the case of, when the excavation speed of more than half of the driving locations is lower than the reference excavation speed, or when the minimum excavation speed is 0.7 times or less of the reference excavation speed,
A method for measuring the activity of a blast furnace core, characterized by making the core inactive.