JPH0238490A - Estimation of moisture content of coal charge to each coke oven - Google Patents

Abstract

PURPOSE:To improve the economy and precision by estimating the moisture content of a coal charge to each oven by comparing the measured value of the temperature of a cut coal from the cutting gate on the bottom of a coal tower with a specified working curve. CONSTITUTION:A moisture meter 3a and a thermometer 4a are provided on the upstream side of a route 1a of a coal conveyor 1 which conveys a coal from a mixing tank through a drier 2 to a coal tower 5 and of a wet conveying route 1b which by-passes the drier 2, and another moisture meter 3b and another thermometer 4b are provided on the downstream side thereof. A working curve which represents the moisture vs. temperature relationship of a mixture containing wet coal and coal of a controlled moisture is prepared on the basis of the measured values. A thermometer is provided at the cutting gate 6 on the bottom of the coal tower 5, and the measured value is compared with the working curve to estimate the moisture content of a coal charge to each coal.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for estimating the moisture content of charged coal for each kiln of a coke oven.

<Prior art> In general, the system for charging coal into a coke oven is as shown in FIG.
Coal is charged into the mixing tank 22 and cut out at a predetermined mixing ratio from the mixing tank 22 to a coke oven 24 by a transport conveyor 23.
The coal is sent to the coal tower 25. In coal tower 25, usually 4~
The coal required for about 8 hours of coke oven operation is stored, and is extracted from the bottom of the coal tower into the coke oven coal loading car and charged in batches to each kiln.

On the other hand, controlling the moisture content of coal is important in coke oven operation.
It is necessary to take actions such as changing the amount of fuel gas supplied in response to fluctuations in coal moisture to keep the fire-off time constant.

Conventional methods for measuring the moisture content of charged coal include taking a sample of coal on the transport conveyor to the coal tower and performing industrial analysis on it, or installing an online moisture meter (e.g. IR method) on the transport conveyor. , methods of measuring moisture have been adopted, and the moisture values measured by these methods are used to control combustion in coke ovens.

However, in the former case, these methods require a long time to analyze and quick action is not possible. In the latter case, although quick action can be taken, it is difficult to grasp the moisture content of the charged coal for each kiln, and when the moisture content suddenly changes, it is impossible to take detailed actions for each kiln. I can't help but stop at the action.

<Problem to be Solved by the Invention> As mentioned above, the moisture value measured by the conventional method is valid as a representative moisture value per furnace group, but as the moisture value of coal charged for each kiln, The accuracy is insufficient for fine-grained combustion control for each kiln.

Furthermore, as one of the latest coal pre-treatment technologies, humidity-controlled coal equipment is sometimes introduced to pre-dry the coal, but the moisture content of the coal at this time is around 5%, and the moisture content of normal coal (wet coal) is 8%.
There is a large difference in the ratio of ~11%. Assuming such equipment, it is fine if the humidity-controlled coal equipment is operating stably, but if the coke production exceeds the equipment capacity or there is a problem with the equipment, it is necessary to use moisture-controlled coal in addition to the humidity-controlled coal. Wet coal must also be fed to the coke oven, making coke oven operation very complicated in this case.

In other words, when moisture conditioned coal and wet coal are mixed in the coal tower, as in the case above, the fire-off time for each kiln will vary greatly, leading to reduced production due to poor fire-off during extrusion, clogging, or carbonization heat loss. This has a negative impact on coke oven operation, such as an increase in

To solve this problem, it is necessary to quickly measure the moisture content of the charged coal in each kiln and adjust the fuel gas supply cock for each kiln. The results were insufficient for estimation.

On the other hand, as a method to measure the moisture content of charged coal for each kiln,
It is possible to install an online moisture meter directly at the bottom of the coal tower, but in this case, not only would there be no suitable installation location for a conventional moisture meter (IR type, etc.), but there would also be problems with maintenance, which would increase construction costs. becomes expensive.

The present invention aims to solve these problems using a simple method, and it is an object of the present invention to provide a method for estimating the moisture content of charged coal for each kiln with high accuracy and at low cost.

Means for Solving the Problems> That is, the present invention provides a method for estimating the moisture content of coal to be charged into each kiln of a coke oven via a coal tower. Create a calibration curve showing the relationship between temperature and temperature, measure the temperature of the coal cut from the cutting gate at the bottom of the coal tower, and apply this temperature to the calibration curve to estimate the moisture content of the charged coal for each kiln. The present invention provides a method for estimating the moisture content of coal charged in each kiln in a coke oven.

The present invention will be explained in more detail below.

The present invention focuses on the fact that coal has sensible heat after its humidity has been controlled by a coal dryer, and that there is a linear relationship between temperature and moisture, and by measuring the coal temperature at the bottom of the coal tower, This method detects the moisture content of the coal that is put into the coal.

Figure 1 shows the relationship between the moisture content and temperature of coal after drying and humidity control from 8.5% moisture content. However, this relationship cannot be unambiguously determined because it is affected by the moisture content of the wet coal at the entrance of the dryer during humidity-controlled coal production and the outside temperature.

In the present invention, as shown in FIG. 2, the coal conveyor 1 from the blending tank normally passes through a route 1a passing through the dryer 2, but as mentioned above, normal wet coal that does not pass through the dryer 2 Make it applicable even when the device is loaded.
For this reason, in addition to the route 1a passing through the dryer 2, a wet coal feeding route 1b is provided. These routes 1a, 1
b meet downstream of the dryer 2, and the coal is charged to the coal tower by the conveyor 1.

Therefore, in the present invention, moisture meters 3a, 3b and thermometers 4 are provided on the upstream and downstream sides of the route 181b, respectively.
Install 8.4b. Based on these measurement data, a calibration curve including wet charcoal and moisture-conditioned charcoal is created, for example, as shown in FIG. 3.

In addition, as shown in FIG. 4, a thermometer 7 is installed at the cutting gate section 6 at the bottom of the coal tower 5, and the temperature of the coal measured by this is used to calculate the charging temperature for each kiln using the above-mentioned calibration curve. Estimate coal moisture. 8 is a coal loading car.

According to this method, the moisture content of the charged coal to each kiln can be estimated accurately and quickly, and is very effective for coke oven operation.
The thermometer installed at the bottom of the coal tower is a general thermocouple, and the moisture meter installed on the coal transport conveyor is an I
For the R type, a radiation thermometer or the like may be used as the thermometer.

Next, an example of implementing the method of the present invention described above will be described with reference to FIG.

The coal carried by the belt conveyor 1 is charged into the coal tower 5 via a route 1a passing through the dryer 2 and/or a route 1b not passing through the dryer 2, and is cut out from the lower gate 6 and sent to the coal loading car 8. It is then charged into a coke oven.
As mentioned above, various problems have arisen at this time because the moisture content of the coal differs depending on the oven of the coke oven.

In order to solve such problems, in the present invention,
Water reservoirs 3a and 3b and thermometers 4a and 4b are provided on the downstream and upstream sides of routes la and lb, respectively.

Continuously measured data from the moisture meter and thermometer are manually input to a calculator 9 to calculate an average value, and then in the next calculator 10, a calibration curve showing the relationship between the moisture content and temperature of the coal is created. This is manually input to the next moisture calculator 13.

On the other hand, the operation of the cutting gate, ie, the predetermined kiln N.

When it is detected that coal is being loaded into the coal loading car 8 for charging, the thermometer 7 installed at the cutting gate section 6 at the bottom of the coal tower 5 measures the temperature of the coal at the cutting gate section 6. This is then manually input to the reading device 12 and becomes temperature data. This is sent to the moisture calculator 13, and the moisture corresponding to the temperature of the coal at the gate is cut out from the calibration curve of moisture and temperature described above and displayed on the moisture display 14, and the kiln number is displayed on the kiln NO display 15. be done. Therefore, since the moisture content of a predetermined oven is displayed, the fuel gas cock for each oven of the coke oven is adjusted accordingly.

This can be done manually or automatically.

FIG. 6 shows the correspondence between the moisture values measured using the method of the present invention explained with reference to FIG. 5 and the results of moisture measurement by industrial analysis of samples of coal actually charged into a kiln. It can be seen that according to the method of the present invention, moisture can be measured with high accuracy.

In addition, Figures 7a and 7b compare the variations in the fire-off time of each kiln when the fuel gas supply amount for each kiln is adjusted using the moisture estimation value for each kiln according to the present invention and when the adjustment is not performed.
As shown in the figure. As is clear from these figures, if the moisture content of each kiln is unknown, it cannot be adjusted, resulting in large variations in fire-off time. On the other hand, if the moisture content of each kiln is adjusted as an index, it is possible to suppress variations in fire-off time.

<Effects of the Invention> As described above, the present invention is excellent in that it is possible to quickly and accurately estimate the moisture content of charged coal for each kiln, and since it uses a thermometer as a measurement means, the construction cost is low, and the moisture content of the coal can be estimated quickly and accurately. It is an extremely effective means of providing indicators for taking prompt and appropriate action in coke oven operations, such as when there is a significant change.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between coal moisture and temperature during humidity control. FIG. 2 is a diagram showing the mounting positions of the moisture meter and thermometer. FIG. 3 is a graph showing a calibration curve of coal temperature and moisture. FIG. 4 is a diagram showing the installation position of the thermometer in the coal tower. FIG. 5 is a diagram of an apparatus implementing the method of the invention. FIG. 6 is a graph showing a comparison between the method of the present invention and the bone-dry method. FIGS. 7a and 7b are graphs showing a comparison of the variation in fire-off time between the method of the present invention and the conventional method. FIG. 8 is a diagram showing a coal charging system. Explanation of symbols 1...Coal conveyor, 1a...Moisture-controlled coal route, 1b...Wet coal route, 2...Dryer, 3a, 3b...Moisture meter, 4a, 4b...Temperature Total, 5... Coal tower, 6... Coal tower lower cutting gate section, 7... Thermometer, 8... Coal loading car, 9... Arithmetic unit (average value), 10... Arithmetic unit (calibration curve creation), 11... Cutting gate operation detector, 12... Temperature data reading device, 13... Moisture calculator, 14... Moisture indicator, 15... Kiln No. Indicator (D.n ko takun'blasphemy 4'<=1 (6/6), 100 million) tlGo匡C%) 1Mucki) drunkenness

Claims (1)

[Claims] In a method for estimating the moisture content of coal that is charged into each kiln of a coke oven via a coal tower, a calibration curve is created that shows the relationship between the moisture content and temperature of the coal before it is charged into the coal tower. A method of charging coal for each kiln in a coke oven, characterized in that the temperature of the coal cut out from the lower cutting gate part is measured, and the temperature is applied to the calibration curve to estimate the moisture content of the charged coal for each kiln. Moisture estimation method.