JPH0853676A - Method for judging damage to coke oven wall - Google Patents

Abstract

PURPOSE:To provide a method for judging damage to a coke oven wall whereby the damage is exactly judged from information on the load current of a drive motor for a pushing-out ram and thus the stop of or difficulty in pushing coke and the resulting damage to the oven wall are prevented through preventive maintenance. CONSTITUTION:The state of damage to a coke oven wall is judged by an index value which is set statistically from the waveform of variation in the load current of a drive motor versus the distance of movement of a ram head in the range of from the position where the speed-switching notch of a pushing-out ram is finally switched to the position where the brake works in everyday operation of a coke oven.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining damage to a coke oven wall.

[0002]

BACKGROUND OF THE INVENTION Blast furnace coke functions as a reducing material, as a heat source, and as a supporting material for maintaining air permeability, and it is essential to stably supply good quality coke to the blast furnace. However, at the beginning of the 21st century, most coke ovens in Japan are said to have reached the end of their life.
To reach the end of the year, alternative coke ovens are currently being studied.

For example, a continuous forming coke oven (for example,
Okuhara et al .: Iron and Steel, S584-587, 1979), JC
R = Jumbo Coking Reactor (for example, Nishioka: fossil of the sun, Agne series 2). However, in any of these technologies, the amount of equipment investment is enormous, and at the present time, the next-generation coke manufacturing technology that can be used 100% in the blast furnace has not been developed.

Therefore, extending the life of the current coke oven, that is, the side wall of the carbonization chamber and the brick wall of the bottom of the furnace (hereinafter referred to as this, which has the greatest effect on the life of the coke oven and which cannot be radically repaired during operation) In the present invention, the state of damage to the side wall of the carbonization chamber and the bottom brick wall is referred to as the furnace wall) is grasped and the damage reduction is studied hard. The damage to the side wall of the carbonization chamber and the brick at the bottom of the furnace is generally caused by a load on the side wall and the bottom of the furnace during coke extrusion, and especially when the coke is blocked in the carbonization chamber and it is difficult or impossible to extrude (hereinafter, each stop
This is a vicious cycle for the life of the furnace because it becomes more prone to stop and clog if the damage to the side wall / furnace bottom becomes greater.

Further, it is expected that the load on the furnace wall / furnace will increase more and more due to the change in coke oven operation technology which is required in the future such as the addition of humidifying coal and weak coking coal. Detecting these stoppages and blockages and performing hot repair while the damage is slight is the most necessary for extending the life of the coke oven. Basic research on the extrusion characteristics of such coke is described in V. I.
Addes: AIM 45th Ironmakin
g Conference, 1986, but there is no technique to prevent the material from being clogged up due to material characteristics and operating conditions, and a furnace that has been severely damaged. There are no examples that have been examined from the perspective of wall conditions or the use of inferior raw materials.

Further, hot repair of the furnace wall of the carbonization chamber is performed by Si, SiO
It is possible by spraying brick materials such as ₂ .
It is actually carried out in actual operation and stops pushing, which has a great effect on reducing the clogging. However, this thermal spray repair requires a total of several tens to 200 hours per kiln, and considering that there are about 100 kilns per furnace group, it is possible to efficiently predict the kilns requiring thermal spray repair. Is very important.

Therefore, from the information obtained during operation, damage to the furnace wall / bottom is detected in advance and repaired to prevent it from stopping and preventing clogging. Techniques to prevent further damage are needed.
For example, Japanese Patent Application Laid-Open No. 3-146589 discloses a technique of determining a furnace wall abnormality from load information applied to a motor during extrusion.

[0008] This technique is a method of judging an abnormality in the furnace wall based on load information applied to the ram when the coke cake in the coke oven is extruded by an extrusion head mounted on the ram, and especially when the ram is started. Abnormality of the furnace wall based on the load information during about 10 seconds until the ram extrusion head contacts and compresses the coke cake and the whole starts and accelerates when switching the notch and powering up the ram. Is a method of diagnosing.

However, in this method, since the condition of the furnace wall is judged from the load information when the ram is powered up after the ram is started, the transient load peak due to the switching of the notch may occur. However, there was a problem that load information, which appeared and was hidden behind it, which means slight damage to the furnace wall, could not be detected with high sensitivity.

[0010]

SUMMARY OF THE INVENTION The present invention provides a determination method for solving the above-mentioned problems, that is, a method for detecting a slight damage to a furnace wall with high sensitivity without being affected by a transient load peak due to notch switching. This is an issue.

[0011]

According to the present invention, coke clogging is prevented by efficiently predicting the time required for repairing the coke oven wall from the operation data of the coke oven and efficiently performing repairs such as thermal spraying. However, the purpose is to extend the life of the coke oven, and based on the load information on the drive motor of the coke oven when the coke cake in the coke oven is extruded by the extrusion ram, In the method of determining damage, the load power or torque of the drive motor of the extrusion ram is measured with respect to the movement amount of the ram head, and the load power or torque of the drive motor of the extrusion ram is measured in the range from the position at which the speed switching notch of the ram is last switched to the operation of the ram brake. A method for judging damage to a furnace wall and a furnace bottom of a coke furnace, which is characterized in that it is judged based on a waveform of load power or torque.

Further, a simple regression on the relationship between the movement amount of the ram head and the load power or torque of the ram drive motor in the range from the position where the speed switching notch of the ram was last switched to the operation of the brake of the ram. Find a straight line,
The sum of absolute values of the difference between the load power or torque data of each drive motor and the value on the single regression line with respect to the moving point of each ram head, or the integrated value obtained by integrating the absolute value of the difference with respect to the range, Alternatively, it can be determined by a total value of absolute values of the difference or a standard value obtained by standardizing the integrated value with each average value.

[0013]

The function of the present invention will be described in detail below. The change in the load power of the ram motor with respect to the moving amount of the extrusion ram head during the operation in the coke oven (the torque of the ram motor may be used) is as shown in FIG. (This curve is called the extrusion waveform). In FIG. 1, the horizontal axis is the position of the ram head during extrusion, and 0 is the extrusion start point. FIG.
As can be seen, there are some sharp peaks and broad peaks in the typical extrusion waveform.

The sharp peak is an electric one at the notch switching position 1, and the broad peak 4 is an electric one.
As disclosed in Japanese Patent No. 146589, it corresponds to starting from compression of coke cake and reflects a part of the damage state of the furnace wall. The waveform is stable after the last sharp peak because the load power of the motor is not affected by the notch switching and the coke cake is steadily starting after position 2 where the notch was last switched. is there.
In other words, the waveform of this portion may reflect a relatively slight damage to the furnace wall / furnace, and the inventors of the present invention judge the damage of the coke oven wall and the furnace bottom from the waveform of this portion. The inventors have found that it is possible to achieve the present invention.

That is, the waveform in the range from the position 2 at which the speed switching notch of the ram was last switched to the operating position 3 of the brake reflects the steady state of pushing the coke cake out of the furnace. Therefore, even if there is local damage to the coke oven wall or oven bottom, the relationship between the displacement of the ram head and the load power or torque of the motor of the extrusion ram in this range has a linear relationship as a tendency. . Depending on the size of local damage on the coke oven wall and the furnace bottom, the linear change superimposes a fine vibration waveform, and the degree of the fine vibration waveform is the fineness of the coke oven wall and the furnace bottom. The inventors of the present invention have found that the degree of damage is reflected.

There are various conceivable indexes for indicating the degree of a fine vibration waveform superimposed on such a linearly changing tendency. For example, (1) the position at which the ram speed switching notch was last switched. From the above, a single regression line is obtained regarding the relationship between the load power or torque of the motor of the extrusion ram and the movement amount of the ram head in the range from the brake operation to the data and regression line of the power or torque of each ram head movement distance. Sum of absolute values of differences from the above values (referred to as index 3). (2) An integrated value obtained by integrating the absolute value of the difference in the moving distance range of the ram head (referred to as index 1). (3) A standard value (referred to as index 2) in which the values of (1) and (2) are standardized by an average value. Can be given.

Each of these index values represents how far the furnace wall / furnace bottom is from an ideal constant surface state, that is, a constant friction coefficient,
When the furnace wall / bottom is in a healthy state, these index values are constant and stable, but when the furnace wall / bottom is in an unhealthy state due to carbon adhesion or brick damage, etc. It will increase.

As mentioned above, this index is
Since the state of the hearth is sensitively reflected, setting a control value can prevent the material from being stopped or clogged, or damage to the furnace wall or the furnace bottom. Furthermore, by adopting such an index and setting it as a control value in daily operations, it is possible to detect relatively minor damage to the furnace wall / furnace in advance, and to repair it to prevent it from stopping or clogging. It also makes it possible to prevent further damage to the furnace wall / furnace bottom.

[0019]

【Example】

Example 1 For an extrusion waveform of a specific kiln of a coke oven having a coking chamber diameter of 460 mm, data from a single regression line in the range from the position at which the speed switching notch of the ram was last switched to the operation of the brake was performed. The daily change in the integrated value of the deviation (index 1) is shown in FIG.

This kiln is a 25-year old kiln. The above indicators for this kiln were stable at low levels, but 1
It increased from around the end of January, and 11/23 to 25 became clogged. Therefore, when a thermal spray repair was carried out on November 26, the index decreased again and became stable, reaching the present level.
During that time, it stopped pushing and no clogging occurred. In this kiln, the management value of the index 1 is 1000 and the operation is performed.

Example 2 Next, FIG. 3 shows the total value of the difference of data from the single regression line in the range from the position where the speed switching notch of the ram was last switched to the operation of the brake for different kilns of the same furnace. Shows the daily change of the value (index 2) obtained by dividing by the average value of the data. This kiln is 29 years old and has become more old. As shown in the figure, in this kiln, the furnace wall was repaired by thermal spraying in August, and both the index and the extrudability were stable, but the index increased from mid-November, and it stopped at 11/25. , Clogged on 12/5.

In other words, it was found that as the index 2 increases, push-stopping and push-clogging occur. In this case, 4.5 to 5 is suitable as the control value of the index 2. Example 3 The same index 1 as in Example 1 was investigated in a further different kiln of the same furnace, and the results are shown in FIG.

By repairing this kiln so that the index does not exceed the control value 1000, the index is stabilized at a low level as shown in the figure, and it is possible to prevent clogging and stopping. It was From these results,
By using the determination method of the present invention, it is possible to accurately predict the time required for repairing the coke oven wall and efficiently perform repairs such as thermal spraying, thereby stopping the coke, clogging it, and further coke oven It has been found that damage to the can be prevented.

[0024]

According to the judgment method of the present invention, since the daily operation data is used as it is, it is possible to accurately predict the time required for repairing the coke oven wall and the oven bottom.
Repairs such as thermal spraying can be carried out efficiently, which makes it possible to prevent the coke from stopping, being blocked, and from damaging the coke oven.

[Brief description of drawings]

FIG. 1 is a waveform showing a change in load power of a ram motor with respect to a moving amount of an extrusion ram head, which is called an extrusion waveform.

FIG. 2 is a first embodiment of the present invention in which the carbonization chamber diameter is 46.
The example of daily change of the management index -1 about the extrusion waveform in a certain kiln with a coke oven of 0 mm is shown.

FIG. 3 is a second embodiment of the present invention in which the carbonization chamber diameter is 46
The example of daily change of the management index-2 about the extrusion waveform in the kiln different from FIG. 2 of the coke oven which is 0 mm is shown.

FIG. 4 is a third embodiment of the present invention, in which the carbonization chamber diameter is 46
The example of daily change of the management index -1 about the extrusion waveform in the kiln different from FIGS.

[Explanation of symbols]

 1 Notch switching position 2 Last notch switching position 3 Brake operating position 4 Broad peak

Front page continuation (72) Inventor Mikiharu Takeda 1 Kawasaki-cho, Chuo-ku, Chiba City Kawasaki Steel Co., Ltd. Steel Research and Development Division Steel Research Laboratory (72) Inventor Hiroshi Itaya Kawasaki-cho, Chuo-ku, Chiba City Kawasaki Steel Co., Ltd. Inside the Steel Research Laboratory, Steel Development and Production Division

Claims (2)

[Claims] 1. A method for determining damage to a furnace wall of a coke oven based on load information applied to a drive motor of the ram when the coke cake in the coke oven is extruded by the extrusion ram, the extrusion ram with respect to a moving amount of a ram head. Measuring the load power or torque of the drive motor, and determining based on the load power or torque waveform in the range from the position where the ram speed switching notch was last switched to when the ram brake operates. Characteristic method for determining damage to the coke oven wall. 2. A simple regression on the relationship between the movement amount of the ram head and the load power or torque of the ram drive motor in the range from the position where the speed switching notch of the ram was last switched to the operation of the ram brake. A straight line is obtained, and the sum of absolute values of the difference between the load power or torque data of each drive motor for each ram head movement point and the value on the single regression line, or the absolute value of the difference is integrated over the range. 2. The method for determining damage to a furnace wall of a coke oven according to claim 1, wherein the integrated value, the sum of absolute values of the difference, or the standard value that standardizes the integrated value is used.