JPH04306294A - Control of expansion pressure on carbonization of coal - Google Patents

Abstract

PURPOSE:To estimate and control the expansion pressure of coal by a simple method without practically measuring the expansion of the coal, by adjusting the coaling degree and the inactive component content in the coal so that the expansion pressure is <= a tolerance limit value. CONSTITUTION:A coaling degree represented by a volatile component content, a carbon content, an average reflection factor, etc., and a correlation between an inactive component content and the expansion pressure of the coal are determined. On the basis of the determined coaling degree and correlation the coaling degree and the inactive component content are adjusted to control the expansion pressure to <= a pre-determined tolerance limit value.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing coke from coal, and more particularly to a method for controlling the expansion pressure of coal during carbonization.

0002

[Prior Art] In the process of producing coke by carbonizing coal, coal expands and exerts pressure on the coke oven.If the expansion pressure is high, the coke oven may be damaged. It is necessary to control the temperature below the limit value based on the strength of the furnace body.

It has been known that many coals with a high degree of coalification expressed by volatile content, carbon content, average reflectance, etc. have a high expansion pressure. Therefore, attempts have been made so far to control the expansion pressure below the limit value based on the strength of the coke oven body by setting an upper limit on the degree of coalification of the coal used in the coke oven.

However, some coals with a high degree of coalification have a relatively low expansion pressure, and conversely, some coals with a relatively low degree of coalification have a relatively high expansion pressure. In some cases, the inflation pressure cannot be determined solely by In addition, there have been attempts to organize the expansion pressure using parameters other than the degree of coalification, such as total expansion coefficient and maximum fluidity, but it has not been possible to organize the expansion pressure using these caking parameters. For this reason, if an attempt is made to manage the expansion pressure based on the degree of coalification alone, the expansion pressure may exceed the limit value and the coke oven may be damaged by the expansion pressure.

[0005] As described above, the expansion pressure cannot be predicted from the coal properties, so in order to avoid damage to the coke oven, the expansion pressure must be determined by actually carbonizing the coal in a test furnace before using it in the coke oven. need to be measured. For inflation pressure measurements, Koppers and Jenkner (H. Kopp
ers and A. Jenkner,Fuel,
10 (1931), 232, H. Koppers a
nd A. Jenkner, Fuel, 10 (193
1), 273) is used, and the expansion pressure measured in the movable wall furnace is 10 to 15 kPa, which is the strength of the coke oven body. This is considered to be the permissible limit value. However, this test furnace is very expensive and requires a large amount of coal material (approximately 400 kg), so it is not a simple measuring method. Furthermore, the reproducibility of the measurement results is poor, and it is not possible to respond quickly when changing the blend of raw coal or the operating conditions of the coke oven.

[0006]

[Problems to be Solved by the Invention] The present invention provides a method for estimating the expansion pressure of coal in a simple method without actually measuring it in a test carbonization furnace. It is an object of the present invention to provide a method of controlling the inflation pressure so that it is below the allowable limit value based on body strength.

[0007]

[Means for Solving the Problems] A feature of the present invention is that the degree of coalification and the amount of inert components are adjusted based on the method of estimating the expansion pressure based on the degree of coalification and the amount of inert components. The method of controlling coal expansion pressure is characterized in that the expansion pressure is controlled to be equal to or less than an allowable limit value.

The present invention will be explained in detail below. As a result of researching the influence of coal properties on expansion pressure, the inventors found that
It has been found that the expansion pressure is controlled by the degree of coalification expressed by volatile matter, carbon content, average reflectance, etc., and the amount of inert components. Note that not only the degree of coalification but also the amount of inert components affects the expansion pressure because the inert components do not soften and melt during carbonization, so gas generated easily escapes from the interface with the active components.
This is thought to be because the gas pressure within the coal seam, which is in a softened and molten state, which is the cause of expansion pressure, tends to decrease. Therefore, by measuring the expansion pressure of various types of coal with different degrees of coalification and amounts of inert components, it is possible to organize the expansion pressures by degrees of coalification and amounts of inert components. A correlation (diagram, table or correlation equation) of inflation pressure can be obtained. Therefore, once the degree of coalification expressed by volatile content, carbon content, average reflectance, etc. and the amount of inert components are determined, this correlation (Fig.
The inflation pressure can be estimated using a table or correlation formula.

[0009] Based on this, a method was devised to control the expansion pressure to be below a predetermined limit value by adjusting the degree of coalification and the amount of inert components. In other words, the expansion pressure can be estimated based on the degree of coalification expressed by volatile content, carbon content, average reflectance, etc., and the amount of inert components.Conversely, based on this estimation method, the blend of coal can be adjusted. By setting the degree of coalification and the amount of inert components within appropriate ranges, it becomes possible to control the expansion pressure to an appropriate range below the allowable limit value.

However, the pulverized particle size of the coal, the charging density, and the oven width of the coke oven have a large effect on the expansion pressure. is known to grow. It is also known that the expansion pressure varies depending on the furnace temperature. Therefore, if the pulverized coal particle size, charging density, and coke oven temperature are different, the influence of these on the expansion pressure should be investigated and the expansion pressure should be corrected, or the degree of coalification and inert components should be adjusted under each condition. It is sufficient to measure the expansion pressures of various types of coal with different amounts and investigate the correlation (diagram, table, or correlation formula) between the degree of coalification, the amount of inert components, and the expansion pressure under each condition.

[0011]

[Examples] Example 1 Using various types of coal, expansion pressures were measured using a carbonization test furnace with a furnace width of 425 mm. The pulverized particle size of the coal at this time is 3m
m or less 85%, charging density is 0.86t/m based on dry coal
3. Moisture content is 3%. FIG. 1 shows the results of the expansion pressure measurement values organized by the volatile matter (VM) and inactive component amount (TI) of the coal and expansion pressure. Figure 1 is a diagram showing the correlation between the degree of coalification, the amount of inert components, and the expansion pressure. Once the degree of carbonization expressed as a ratio and the amount of inert components are determined, the expansion pressure can be estimated from this diagram.

Therefore, using this diagram, by adjusting the degree of coalification (volatile content in this case) and the amount of inert components of the coal used so that the expansion pressure is below the allowable limit value,
The inflation pressure can be controlled. In this case, for example, if the allowable limit of inflation pressure is 10 kPa, this figure shows that the amount of volatile matter (VM) and inert components (
TI) can be determined. For example, if the VM is 30%, coal with a TI of 15% or less is dangerous, and the VM is 25%.
Therefore, coal with a TI of 25% or less is dangerous. Also T
If I is 15%, VM is 30% or less, if TI is 20%, VM is 27% or less, if TI is 25%, VM is 25% or less,
If the TI is 30%, coal with a VM of 22% or less is dangerous.

[0013]

[Effects of the Invention] According to the present invention, expansion pressure can be properly controlled, thereby preventing damage to the coke oven, reducing repair costs, and extending the life of the oven, which has a large economic effect. .

[0014] Furthermore, the test cost for measuring inflation pressure can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the correlation between the degree of coalification, the amount of inert components, and the expansion pressure.

Claims (1)

[Claims] [Claim 1] Based on the method of estimating the expansion pressure based on the degree of coalification and the amount of inert components, the degree of coalification and the amount of inert components are adjusted so that the expansion pressure is below the allowable limit value. 1. A method for controlling coal expansion pressure, the method comprising: controlling coal expansion pressure;