JPS61264091A - Method for carbonizing coal - Google Patents

Abstract

PURPOSE:To sufficiently burn raw gas even if there is leak of the raw gas in a fuel chamber and prevent the incomplete combustion, by detecting the charging of coal into a coke oven, and stopping or reducing the feed rate of a fuel to the coke oven for a given time after charging the coal. CONSTITUTION:A pressure detecting device 19 for detecting the internal pressure is provided in a carbonization chamber 14 to detect the charging of coal into the carbonization chamber 14. The detecting device 19 detects the pressure in the carbonization chamber 14 at all times to output a signal corresponding to the pressure to a pressure transmitter 20, which transmits a signal corresponding to the above-mentioned input signal to a comparator 21 for input thereto. The input signal is compared with the preset pressure by the comparator 21, and a signal is output to a control device 22 when the internal pressure of the carbonization chamber 14 exceeds the set pressure. The calculation is carried out on the basis of the signal from the comparator 21 in the control device 22, and control operation for shutting a flow control valve 11 is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for carbonizing coal in which the amount of fuel i4 supplied into a coke oven is stopped or reduced for a predetermined period of time.

[Conventional technology]

The structure of a coke oven shown in FIG. 1 is generally used. In other words, 1 is a coke oven, in which a combustion chamber 2 and a heat storage chamber 3 are formed, and each compartment 2.3 is divided into two parts, an intake side and an exhaust side, and combustion air 4 and combustion gas 5. is introduced into the popular side of the combustion chamber 2 through the popular side of the heat storage chamber 3, where it is combusted. The exhaust gas here passes from the exhaust side of the combustion chamber 2 to the exhaust side of the regenerator 3, and after preheating the combustion air 4 and the combustion gas 5 here, is discharged to the exhaust gas flue outside the furnace. 6 is exhaust gas. A flow control valve 11 and a cutoff valve 12 are arranged in the combustion gas 5 conduit. Coal is charged into a carbonization chamber (not shown) adjacent to the combustion chamber 2, and is carbonized by the combustion. The coke formed by carbonization is forced out of the carbonization chamber. A typical carbonization cycle is 15-20 Hr.

Conventionally, the amount of heat supplied to the coke oven 1 was controlled as shown in Fig. 2 (
It is carried out by the method shown in al or FIG. 2 fbl.

That is, Fig. 2 (fa) is a method in which the supply amount of combustion gas is always maintained at a constant value, and Fig. 2 (bl) is a method in which the supply amount of combustion gas is maintained at a preset value over time during the mooring time. This method minimizes the amount of heat supplied (Jli) during the entire mooring time by changing the value.

[Problem that the invention seeks to solve]

When this conventional combustion gas supply heat needle control method is applied to a coke oven consisting of a coke oven, 0.2. Co
, CH4 concentration over time are shown in FIG. 3, and the static pressure in the coke oven carbonization chamber is shown in FIG.

According to Figure 3, although 02 remains at a roughly constant value over the entire carbonization time, the settling time after coal charging (about 10 minutes for a human body) is extremely low, and unburnt components such as CO and CH4 peak appears within the above time period. Also the fourth
According to the figure, the settling time (
(about 10 minutes), the amount of gas generated in the furnace is large and the pressure inside the furnace is high. As this example of a coke oven is old, the silica bricks between the combustion chamber and the carbonization chamber are worn out, the joints are cut, etc., and the raw gas generated leaks into the combustion chamber, as shown in Figure 3. It is estimated that a decrease in 02 and peaks in GO and CH4 are observed as shown in .

Therefore, the partition wall (carbonization wall) between the carbonization chamber and the combustion chamber is worn out.
In a coke oven where joint breakage has occurred, see Figure 2 (
Al, with only the control shown in (b), it is not possible to efficiently prevent incomplete combustion due to gas leakage from the coking chamber to the combustion chamber caused by disturbances such as an increase in the pressure inside the furnace during coal charging. There was a problem that it was difficult to prevent the generation of unburned components and soot.

This invention was made by paying attention to the problems of the conventional example, and aims to effectively prevent incomplete combustion.

[Means for solving problems]

In the coal carbonization method of the present invention, the detection means detects the charging of coal into the coke oven, and stops or reduces the amount of fuel supplied to the coke oven for a predetermined period of time from the time of coal charging.

〔Example〕

FIG. 5 shows a first embodiment of the present invention.
2 is a coke oven, 2 is a combustion chamber of coke oven 1, 3 is a regenerator of coke oven 1, I4 is a carbonization chamber of coke oven 1, 7 is a riser pipe, 17 is a dry main, and coke 16 is placed in carbonization chamber 14. is inside, and both sides thereof form a door 8. Carbonization chamber 14
A coal loading car 18 is arranged above the coal loading car 18, and coal, which is a raw material for coke 16, is supplied into the carbonization chamber 14 from this coal loading car 18.

Although the carbonization chamber 14, the combustion chamber 2, and the heat storage chamber 3 are shown separately in FIG. 5 for convenience of explanation, they are actually adjacent to each other to form an integrated coke oven 1. .

, combustion air for coke oven 1 4. Combustion gas 5
The means for supplying the coke oven 1 and the means for discharging the exhaust gas 6 from the coke oven 1 are the same as those shown in FIG. 1 showing the conventional example.

Although not shown in the drawings, the coal loading car 18 is equipped with a device that detects that coal is being charged into the carbonization chamber 14.
The detection signal is output to control word W9. The control word N9 closes the flow rate regulating valve 11 for the combustion gas 5 based on the signal, thereby regulating the supply of the combustion gas 5 to the combustion chamber 2 for a predetermined period of time.

As explained in the conventional example, this time corresponds to a predetermined time (approximately 10 minutes) after coal charging, when the amount of gas generated in the furnace is large and the pressure inside the furnace is high.

Note that even during this period, the combustion air 4 is constantly supplied in a constant amount under the control of the flue draft.

As a result, the generated gas that leaked into the combustion chamber 2 due to an increase in the internal pressure of the coke oven is completely combusted by the combustion air 4, which is in large excess compared to the combustion gas 5 whose supply amount has decreased due to regulations. let Therefore, generation of unburned components and soot and dust can be prevented.

FIG. 6 shows the furnace pressure and the opening degree of the flow rate regulating valve 11 in this example. From this figure, the pressure inside the furnace is normally 1
It can be seen that although the pressure is maintained at around 0 Dragon Aq, it increases at the same time as the coal charging starts, and this pressure rising state continues for about 10 minutes.

Therefore, when coal starts to be charged from the coal loading car 18 to the carbonization chamber 14, the coal loading car 18 indicates that this charging has started.
The detection device detects and outputs a signal to the control device 9. When the control device 9 receives the signal, it controls the flow rate regulating valve 11 to close.

This closing time corresponds to the time during which the pressure inside the furnace is rising, and is determined in advance through experiments, and in this embodiment is about 10 minutes for the human body. Therefore, the interval ζ, 1
No combustion gas 5 is supplied to the combustion chamber 2.

In addition, in the above embodiment, the opening degree of the flow adjustment valve 11 was set to 80% in the open state, and 0% in the closed state, but it is also possible to change these values, and it is also possible to In addition to the two-stage control, it is also possible to adjust the opening degree in several stages over time.

Thus, if the century of combustion gas is regulated at the time of coal charging, 02? The WA degree is improved as shown in FIG. Compared to the conventional method (Fig. 3), this means that even though the pressure inside the furnace rises rapidly for about 10 minutes after charging the coal and there is a leakage of gas from the carbonization chamber 14, the combustion It is recognized that this is because the regulation of the supply of gas 5 increases the amount of combustion air for the amount of combustion gas 5 in the combustion chamber 2, and this causes the leaked raw gas to be combusted.

Therefore, no unburned components, soot, etc. are generated in the exhaust gas.

In addition, in coke oven operation, especially old coke ovens, due to the generation of unburned components, soot, etc., combustion air is
Although it was not possible to lower L, by applying this invention, as shown in FIG. 8, it became possible to operate at a low air ratio, and the coke production unit consumption became significantly lower. Note that FIG. 8 shows the results of applying this invention from June.

FIG. 9 is a diagram showing a second embodiment of the invention. That is, in this embodiment, a pressure detection device 19 for detecting the pressure inside the carbonization chamber 14 is installed to detect the charging of coal into the carbonization chamber 14.

The pressure detection device 19 is installed on the ceiling of the carbonization chamber 14, the door 8. rising pipe 7
However, it may be installed anywhere as long as the pressure increase in the carbonization chamber 14 can be detected.

This pressure detection device 19 constantly detects the pressure within the carbonization chamber 14 and outputs a signal corresponding to the detected pressure to the pressure transmitter 20. The pressure transmitter 20 transmits a signal corresponding to the input signal to the comparator 21 and inputs it thereto. The comparator 21 compares the pressure with a preset pressure, and when the internal pressure of the carbonization chamber 14 exceeds this set pressure, a signal is sent to the control device.
Output on '22. The control device 22 has an iJ calculation function, performs calculations based on the signal from the comparator 21, and controls the closing of the flow rate regulating valve 11.

FIG. 10 is a diagram showing the relationship between the charging of coal into the carbonization chamber 14, the internal pressure of the carbonization chamber 14, and the opening degree of the flow rate regulating valve 11, and shows that the internal pressure of the carbonization chamber 14 exceeds the set pressure due to coal charging. At times, the meteor adjustment valve 11 closes, and when the internal pressure becomes lower than the set pressure, the flow rate adjustment valve 11 opens. When the flow rate regulating valve 11 is opened, its opening degree is approximately 75%. In this example, the open state of the flow rate regulating valve 11 is 75%, and the closed state is 0%. and outputs a signal corresponding to the difference to the control device 22.
In step 2, the flow rate regulating valve 11 may be controlled so that the opening degree corresponds to the difference value.

Figure 11 shows the relationship between the charging of coal into the carbonization chamber 14, the internal pressure of the carbonization chamber 14, the exhaust gas 0□, and the unburned components in the exhaust gas. Regarding the relationship with the fuel components, results similar to those shown in FIG. 7 in the first embodiment are obtained.

However, in the case of FIG. 11, the occurrence of unburned components in the exhaust gas is recognized, although it is extremely small.

Furthermore, in the past, it was not possible to lower the combustion air ratio in coke oven operations, especially in aging coke ovens, due to the generation of unburned components, soot, etc., but by applying this invention, the combustion air ratio can be reduced. As shown, it has become possible to operate at a low air ratio, and it has also become possible to significantly reduce the coke production unit consumption. Note that FIG. 12 shows the results of applying this invention from June, and has a similar curve to FIG. 8, which describes the first embodiment.

In addition, in each of these examples, the supply of combustion gas 5 is regulated when charging coal into the carbonization chamber 14, but the supply of combustion air 4 may be increased in parallel with this regulation or without this regulation. It is also possible.

As a result, the amount of fuel supplied to the coke oven can be reduced unnecessarily, and the same effect as in the embodiment described above can be obtained.

According to the above two embodiments, the combustion air supply meter is maintained constant and the fuel supply amount is reduced during coal charging, and the following special effects are achieved. In other words, in the conventional example, if a large excess of combustion air is supplied throughout the carbonization cycle in order to prevent incomplete combustion during coal charging, there is a problem of increased exhaust gas heat loss. There is a problem in that reducing the amount of combustion air supplied to prevent heat loss causes air pollution due to the generation of black smoke from chimneys due to incomplete combustion. It is possible to simultaneously prevent heat loss and incomplete combustion of exhaust gas without supplying air.

〔Effect of the invention〕

As explained in J.J., according to the coal carbonization method of the present invention, even if raw gas leaks into the combustion chamber of the furnace due to the pressure inside the furnace that increases due to coal charging, the raw gas leaks compared to the combustion air. Since the supply of fuel is reduced, the amount of combustion air relative to the fuel is increased, and the leaked raw gas can be sufficiently combusted.

Therefore, it is possible to suppress the generation of unburned components, soot, and soot in the exhaust gas. Furthermore, the coke consumption rate can also be reduced.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the combustion chamber and heat storage chamber in a coke oven, Figure 2 (al kl is a graph showing an example of conventional heat amount control, Figure 2 (bl is a graph showing an example of the same area, Figure 3 is a graph showing changes in the amount of 0□ and unburned components generated in a conventional carbonization chamber, Figure 4 is a graph showing changes in furnace pressure in a conventional carbonization chamber, and Figure 5 is a graph showing changes in the amount of 0□ and unburned components generated in a conventional carbonization chamber. 6 is a graph showing the relationship between the change in the pressure inside the coking chamber and the opening degree of the fuel flow rate regulating valve in the first embodiment, and FIG. Figure 8 is a graph comparing 0□ contained in exhaust gas and the coke unit ratio before and after applying the first embodiment, Figure 9 is a graph showing the change in the amount of 0□ contained in the exhaust gas. Explanatory diagram showing 10th
The figure is a graph showing the relationship between the transition of the pressure inside the coking chamber and the opening degree of the fuel flow rate regulating valve in the second embodiment.
A graph showing the change in the internal pressure of the coking chamber furnace and the change in the amount of 02 and unburned components generated in the coking chamber in the example,
FIG. 12 is a graph comparing the 02 contained in the exhaust gas and the coke consumption rate before and after the application of the first embodiment. I... Coke oven, 2... Combustion chamber, 3... Heat storage chamber, 4... Combustion air, 5... Combustion gas, 9...
Control device, 11...Flow W adjustment valve, 14...Carbonization chamber,
16... Coke, 18... Coal loading car, 19... Pressure detection device, 20... Pressure transmitter, 21... Comparator, 22... Control device. to the side

Claims (2)

[Claims] (1) A method for carbonizing coal, which comprises detecting the charging of coal into a coke oven using a detection means, and stopping or reducing the amount of fuel supplied to the coke oven over a predetermined period of time from the time of coal charging. . (2) Detection of coal charging is performed by any one of a coal charging detector installed in a coal loading car, a dust concentration detector in a coke oven, and a pressure detector in a coke oven as described in claim 1. method of carbonizing coal.