JPH07108977B2 - Coke oven carbonization control method - Google Patents

Description

The present invention relates to a carbonization control method for carbonizing carbon by a coke oven.

[Conventional technology]

Conventionally, in order to produce high quality coke in a coke oven, for example, a pretreatment method such as a forming coal blending method or a coal classification and pulverization method has been adopted.

In addition to such a method, in recent years, a method of producing a high-quality coke by changing a heating pattern in the carbonization process or energy saving has been proposed.

For example, in JP-A-58-222183, it is clarified that the coke quality is governed by the temperature rising rate in the softening and melting zone of the coal and the temperature of the output kiln coke, and the temperature of the output kiln coke is at the same level as in the normal operation method. While maintaining
A method of setting a heating pattern so that the temperature rising rate is 5 ° C./minute or more is disclosed.

Further, in JP-A-59-179581, a timing for switching from a large flow rate heating at the initial stage of carbonization to a small flow rate heating as a method for improving the coke quality, particularly the strength after hot reaction, while saving energy of about 10%. The charcoal temperature is 350
It is disclosed to be carried out when the temperature reaches ~ 700 ° C.

The former aims at maximizing the coke quality improvement effect of the energy required for carbonization at the level of the normal operation method, and the latter aims at both energy saving and quality improvement effect. Depending on the content of the heating pattern in the carbonization process, it is possible to make the coke quality level the same as normal operation and maximize the energy saving.

What kind of heating pattern to use, that is, how to set the respective merits of energy saving and quality improvement effect, depends on the coking coal situation, energy price system, etc. Good.

As described above, this selection gives 100
% (Energy saving merit is 0%) to 0% (energy saving merit is 100%), but in any case, when producing coke, the operator sets a target value and achieves it. Must.

That is, it is important for coke production to set the quality improvement target value (inevitably, the energy saving target value is determined) and to achieve it.

On the other hand, none of the above proposals describes a general heating pattern, and does not guarantee that the discharged coke is maintained at the target quality. Even in the latter case, when the charging charcoal property (for example, water content) changes, the time to reach a certain temperature in the coal changes (that is, the heating rate also changes, and as a result, the coke quality also changes. Therefore, switching the fuel from the high flow rate to the low flow rate at the time when the temperature in the coal reaches 350 to 700 ° C does not guarantee that the target coke quality is obtained.

[Problems to be solved by the invention]

The present invention focuses on the fact that the quality of coke is mainly controlled by both the rate of temperature rise in the softening and melting zone of coal and the temperature of the output kiln coke, and by adopting the carbonization control method linking both, the target coke It provides a method for producing coke that guarantees quality.

[Means for solving problems]

The carbonization control method of the present invention, based on the target coke quality set in the coke oven, sets a target value for the heating rate and the output kiln coke temperature in the softening and melting zone of coal, and the actual value of the heating rate during carbonization. Is estimated by the change pattern of the generated gas temperature, the estimated actual value is compared with the target value to obtain a deviation, and the target value of the output oven coke temperature is corrected based on the obtained deviation, and the subsequent heating is performed. Characterized by modifying the pattern.

The inventors of the present invention have found that the time between reaching the peak point (hereinafter, referred to as T _max ) seen in the known pattern of change in the generated gas temperature (FIG. 1) and the above-mentioned temperature rising rate is the second value. As shown in the figure, it was found that there is a very high degree of correlation, which is expressed by the equation.

aT _max + b = V _c ... However, V _c is a temperature rising rate in the softening and melting region of the coal (approximately 300 to 500 ° C.), and a and b are constants.

This is because T _max is an index (the time until the temperature in coal reaches about 600 ° C.) originally indicating the carbonization speed, and therefore has a strong relationship with the temperature rising rate.

As is known (for example, Japanese Patent Application Laid-Open No. 54-146802), T _max is used for the determination of burnout by a thermocouple installed in the rising pipe, and these are used to detect the temperature rising rate. The use of is advantageous in that it is unnecessary to install a new special detection end.

〔Example〕

Hereinafter, the features of the present invention will be specifically described by way of examples with reference to the drawings.

FIG. 3 is a flow for explaining the carbonization control method of the present invention, FIG. 4 is a control block diagram, and FIG. 5 is a graph showing an example of a heating pattern.

3 and 4, the target value of coke quality is
As described above, the operator compares the energy saving level with, for example, the most economical design and determines the target values of the heating rate and the output kiln coke temperature in the softening and melting zone of the coal based on the design.

The following equations are used to determine these two target values.
The CSR indicates the strength of coke after the hot CO ₂ reaction.

Carbonization heat _{(H c) = aT c +} b ...... However, T _c is Dekama coke _{temperature, CSR = cT c + dV c} + e ...... However, V _c the heating rate, c, d, e is a constant .

That is, by designing the amount of dry distillation heat to a certain level, the temperature of the output coke coke is determined, and then the required heating rate is determined from the design value of coke quality (CSR). The formula is determined by the coal properties and is not necessarily limited to the above.

Next, a heating pattern that achieves these two target values is generated. This generation is based on the simulation result of the coke oven heat transfer model.

This heating pattern may be the flow rate of the heating material,
It may be generated as the carbonization furnace temperature (combustion chamber temperature).

FIG. 5 shows the case where the temperature is generated as the dry distillation furnace temperature.

When the coal is charged into the coke oven, heating and dry distillation are advanced along the heating pattern, and the actual heating rate in the softening and melting zone of the coal is detected as T _max in the above-mentioned generated gas temperature pattern. presume. The actual temperature increase rate is compared with the target temperature increase rate, and the deviation (deviation) of the coke quality from the target value due to this deviation is calculated. This calculation is performed based on the above formula.

Next, in order to correct the deviation (deviation) of the coke quality from the target value, the target firing coke temperature is modified,
Based on this, the subsequent heating pattern is corrected. This target kiln temperature is corrected based on the equation.

It should be noted that the output kiln coke temperature may be detected and calculated by a radiation thermometer installed in the coke guide car or a furnace wall temperature installed in the extruder ram head, and the difference between the actual output kiln coke temperature and the target output kiln coke temperature This is incorporated in the generation of the heating pattern in the next cycle, and the deviation can be minimized.
Also, regarding the deviation between the target heating rate and the actual heating rate,
Incorporated in the generation of the heating pattern in the next cycle. Also, the target heating rate and the actual heating rate (estimated value from T _max )
Deviation is also taken into account in the generation of the heating pattern in the next cycle.

The example of FIG. 5 shows the carbonization time for 11 coke ovens.
It shows the one to which the present invention is applied during the operation for 24 hours (100% coke oven operation rate). The actual temperature increase rate is detected at 16 hours and 30 minutes after charging the coal, and It is the example which changed the subsequent heating pattern according to the deviation. The operation specifications in this case are as shown in Table 1, and the coke quality when the latter half of the heating pattern is not corrected is -1.2 to +0 in the strength after hot reaction with respect to the target value. Despite the change of 7%, in the present invention, ±
It is maintained at 0.2% and the effect is clear.

The variation in the actual heating rate with respect to the target heating rate in Table 1 is such that the initial target heating pattern is constant within the change range of the normal charging coal properties (moisture, volatile matter, charging amount, etc.). It occurs in the case of

〔The invention's effect〕

As described above, in the carbonization control method of the present invention, by controlling the heating pattern based on the temperature rising rate of coal in the softening and melting region and the temperature of the kiln coke,
Coke of target quality can be efficiently produced.

[Brief description of drawings]

FIG. 1 is a graph showing the temperature change of the generated gas discharged from the coke oven, and FIG. 2 is the elapsed time T _max to reach the peak point in the temperature fluctuation pattern and the temperature rise of coal in the softening and melting region. FIG. 5 is a graph showing the relationship with the speed V _s , FIG. 3 is a flow for explaining the carbonization control method of the present invention, FIG. 4 is a block diagram showing a control system used in the method, and FIG. [Fig. 3] is a graph showing an example of a heating pattern.

Front Page Continuation (72) Takashi Sato Inventor Takashi Sato 1-1-1, Edamitsu, Hachimanto-ku, Kitakyushu, Fukuoka Prefecture (72) Yoichi Naganuma 1618 Ida, Nakahara-ku, Kawasaki-shi, Kanagawa Address: Nippon Steel & Co., Ltd. First Technology Research Institute (72) Inventor Keihachiro Tanaka 1618, Ida, Nakahara-ku, Kawasaki-shi, Kanagawa Nippon Steel & Co., Ltd. First Technology Research Institute (56) References 56-72076 (JP, A) JP-A-52-12201 (JP, A) JP-A-58-222183 (JP, A)

Claims (2)

[Claims] 1. In a coal carbonization process using a coke oven, target values are set for the temperature rising rate and the output coke temperature in the temperature range in which the charged coal softens and melts, and the heating pattern is set based on the target values. The actual value of the temperature increase rate at time is estimated by the change pattern of the generated gas temperature, and the estimated actual value is compared with the target value of the temperature increase rate to obtain a deviation,
A method for controlling the carbonization of a coke oven, characterized in that the subsequent heating pattern including the temperature of the output coke is corrected based on the obtained deviation. 2. A dry distillation control method for a coke oven, which comprises correcting the heating pattern for the next cycle based on the temperature rise rate and the deviation of the coke temperature in the output kiln according to claim 1.