JPS6256197B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for accurately predicting the point in time when coal is carbonized in a coke oven and the generation of coke is completed, the so-called burn-off point, using changes in the temperature of generated gas.

Conventionally, a method for determining a fire failure using a change in temperature of generated gas has been proposed, for example, in Japanese Patent Publication No. 46-6497. This conventional method consists of the maximum temperature X of gas generated during carbonization in a coke oven and the gas temperature Y at the time of fire-off (visual fire-off) determined by a fire monitor.
The relational expression Y = a , calculate _its maximum _temperature
This method determines when the fire has fallen by measuring and detecting Y ₁ .

The fire detection described above is carried out by a skilled person known as a fire monitor, and the method is to open the top cover of the riser pipe of a coke oven and observe the color of the gas coming out of it to determine whether or not the fire has fallen. was determining whether

According to this conventional method, the top cover is not opened;
Although it is possible to determine whether a fire has fallen without the need of an expert, it has been difficult to accurately determine the fire because of the following reasons.

Figure 1 shows a scatter diagram between the maximum temperature is as low as 0.52, which is the fire-fall temperature calculated from the maximum temperature x ₁ for fire-fall judgment.
Y ₁ includes a large error. The reason for the low correlation coefficient is that, according to the research results of the present inventors, the generated gas temperature changes even in the same furnace due to the influence of the furnace temperature, coal moisture, and coal loading amount, and that
After the temperature drops by about 100℃, the amount of gas generated is small, so the gas temperature tends to become unstable.
As shown in the figure, the gas temperature may be hunting, or even if there is no hunting, the temperature drop rate will fluctuate (become larger or smaller) near the above 100℃ drop than the previous temperature drop rate.
This phenomenon is thought to be due to the fact that this phenomenon tends to occur.

Since the fire-fall temperature is predicted based on the absolute value of the generated gas temperature, absolute temperature measurement errors due to carbon adhesion to the gas thermometer installed in the riser pipe or the connection pipe between the riser pipe and the dry main, and the gas Errors occur in the predicted fire temperature due to absolute temperature measurement errors due to changes in the installation (temperature measurement) position before and after replacing the thermometer.

According to the investigation results of the generated gas temperature pattern by the present inventors, when the maximum temperature X is at one point (as shown by the solid line in Figure 2)
There are cases where the maximum temperature X continues for about one hour (as shown by the broken line in FIG. 2).

From maximum temperature X℃ to (maximum temperature .

It has been found.

The present invention eliminates the above-mentioned drawbacks and provides a method for accurately predicting the fire-fall time.

The present invention was developed as a result of various studies on a method for determining a fire failure without measuring the unstable region of the generated gas temperature after reaching the maximum temperature until the visual fire failure point.The gist of the invention is as follows. That's right.

The temperature of the gas generated during carbonization in a coke oven is measured with a thermometer installed in the riser pipe or the connection pipe between the riser pipe and the dry main, and the maximum temperature θ
_MAX is detected and the set temperature Z is determined from the maximum temperature θ _MAX .
The relational expression Y=a
The temperature change of the generated gas during carbonization is measured sequentially, the maximum temperature θ _MAX is detected, and the elapsed time X ₁ from charging at the time when the temperature drops from the maximum temperature θ _MAX to the above set temperature Z ℃ is detected. Substitute into the above relational expression and find the fire fall time
A method for predicting fire-off time in a coke oven, characterized by calculating Y ₁ .

However, the above Z°C is a constant value of 50 to 100°C.

Next, the present invention will be explained in detail using the drawings.

Fig. 3 shows a part of a coke oven. Reference numeral 1 denotes a rising pipe for guiding the gas generated in the oven 4 to a collecting pipe (dry main) 6, which has a top cover 2 at the top. . 3 is a thermometer for detecting the temperature of the generated gas rising inside the riser pipe 1. 5 is coke in the middle of carbonization. Figure 4 shows an example of how the temperature of the generated gas changes over time from the time the raw coal is charged until the coke is extruded using the thermometer 3. In this example, the maximum temperature θ _MAX is reached several hours before the burnout is detected. The temperature decreases as the flame is detected and approaches the end of the fire.

The relationship between the elapsed time X from charging when the maximum temperature θ _MAX drops by the set temperature Z° C. shown in FIG. 4 and the visual fire-off time Y can be expressed by a linear equation, that is, Y=aX+b.

The set temperature Z° C. is set outside the unstable region of the generated gas temperature in the temperature change pattern shown in FIG. 2 and outside the curve change region immediately after the maximum temperature. That is, the set temperature Z°C is set to a constant value of 50 to 100°C.

The constants a and b in the above relational expression have values specific to each furnace and kiln, and for a certain kiln, a large number of visual fire-off times Y and time X for the above set temperature Z°C to fall from the maximum temperature θ _MAX were collected. Perform statistical analysis and find constant a,
Find b.

Once these constants a and b are determined, the maximum temperature θ _MAX is detected, and the elapsed time X ₁ from charging at the time when the set temperature Z°C has fallen from that temperature θ _MAX is detected, Y = aX + b
By substituting and calculating the relational expression, the fire fall time Y ₁
can be predicted.

In this way, in the present invention, the point θ _MAX is not the point θ MAX, but the point θ _MAX
-Z)°C point is adopted, so in a temperature pattern where the maximum temperature continues for about 1 hour as shown in Figure 2, the elapsed time X ₁ from charging at that point can be easily and uniquely determined. can.

In addition, in the present invention, the temperature is measured in the stable temperature range up to (θ _MAX - Z) °C without measuring the temperature in the unstable temperature range in the descending range from the maximum temperature of the generated gas temperature pattern. _MAX -Z)°C is detected and the elapsed time from charging at the time of detection _X1 is used to predict the fire-off time _Y1 , so the fire-off time can be accurately predicted 30 to 60 minutes in advance. can.

Furthermore, the present invention measures the absolute temperature of the generated gas, which is used to predict the fire-off time (θ _MAX
-Z) This is done to detect the elapsed time from charging at the point in time, and absolute temperature measurement errors may occur due to carbon adhesion to the thermometer or changes in the temperature measurement position before and after replacing the thermometer. However, these errors do not affect the detection error of the elapsed time detected to predict the fire fall time, so
It is possible to accurately predict the fire fall time. For example, △t ₁ shown in Fig. 5 indicates the error that the absolute temperature detection error due to carbon adhesion gives to the elapsed time X that should be detected for predicting the fire-off time Y. It is clear that the error has no effect as a detection error in the elapsed time on which the fire fall time prediction is based.

To detect the maximum temperature θ _MAX , use a temperature detection device,
It can be detected using a temperature storage device and a calculation device.
That is, the temperature in the riser tube 1 during carbonization is measured intermittently over time, the previously measured temperature θ′max is stored in a storage device, and the difference between the currently measured temperature θ _i and the above θmax (θ _i −θmax) is calculated. is calculated by an arithmetic device, and when the value is zero or positive, the temperature θ _i is stored as θmax, and when it is negative, the θmax is stored as is.

This negative state continues for a certain period of time (approximately 30
minute), this θmax can be detected as the maximum temperature _θMAX .

Next, in order to detect the point in time when the set temperature Z°C has fallen from the maximum temperature θ _MAX and the elapsed time Can be detected.

That is, as soon as the maximum temperature θ _MAX is detected as described above, (θ _MAX −Z) is calculated using the preset temperature Z° C. Then, the temperature θi measured after this and the above calculation were memorized (θ _MAX −
In other words, when the difference from the maximum temperature θ MAX to Z) becomes zero, the temperature (θ _MAX - Z) is detected and at the same time the elapsed time is read from the elapsed time storage device to reduce the maximum temperature θ _MAX to the set temperature Z°C. It is possible to detect the elapsed time X from the time of charging.

The fire-off time can be predicted by substituting the elapsed time X into the above-mentioned relational expression and calculating the fire-off time Y. Figure 6 shows a scatter diagram of the fire-off time predicted by the relational equation with the set temperature Z = 70°C and the visually observed fire-off time. It is clear that it is possible to predict

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams of the drawbacks of the conventional method, and Figure 3
4, 5, and 6 are explanatory diagrams of the method of the present invention. 1... Rising pipe, 2... Top cover, 3... Thermometer, 4... Coke oven, 5... Coke, 6...
...Dry mane.

Claims (1)

[Claims] 1. Measure the temperature of the gas generated during carbonization in a coke oven with a thermometer installed in the riser or the connecting pipe between the riser and the dry main, and calculate the maximum temperature θ.
_MAX is detected and the set temperature Z is determined from the maximum temperature θ _MAX .
The relational expression Y = a Measure temperature changes sequentially, detect the maximum temperature θ _MAX , detect the elapsed time X ₁ from charging when the set temperature Z°C drops from the maximum temperature θ _MAX , and substitute it into the above relational expression. A method for predicting fire-off time in a coke oven, characterized by calculating fire-off time _Y1 . However, Z℃ is
Adopt a constant value of 50-100℃.