JP4676844B2 - Combustion removal method for carbon adhering to coke oven carbonization chamber - Google Patents

Description

  The present invention relates to a method for burning and removing carbon adhering to a coke oven carbonization chamber.

In the coke oven carbonization chamber, carbon generated by pyrolysis of the dry distillation product gas and pulverized coal scattered at the time of charging the coal adhere to the furnace wall and coke to form adhering carbon. This carbon attached to the furnace wall, as it grows on the furnace wall, lowers the furnace wall thermal conductivity and reduces the effective volume of the carbonization chamber, thus reducing furnace productivity and making it impossible to extrude coke. It becomes a cause of so-called clogging, and regular removal work is required.
The following method is well known as a method for removing the carbon attached to the carbonization chamber. (A) Using a sharp jig with a tip of 4 to 5 m in length, it is pushed down manually.
(B) One or both of the furnace lids for coke extrusion and the gas riser pipe are opened, and air is introduced into the carbonization chamber from the furnace lid portion by natural draft.

  However, in the removal method by mechanical action as in (a), the carbon layer is completely peeled from the furnace wall. This is not preferable because it requires a worker to take 15 minutes or more to carry out heavy labor in an adverse environment such as high heat and dust. In the method (b), the furnace wall in the vicinity of the air introduction part passes through the part even after the carbon is initially incinerated and removed, and receives excessive overcooling locally. In addition to damage caused by brick spalling and joint opening, oxygen used for combustion is about a fraction of that entering the carbonization chamber, and most of the air does not contribute to combustion. Since it is discharged outside, the amount of carbon combustion cannot be increased. For this reason, a long time is required for the carbon removal work, and production is hindered.

  In order to solve these problems, in a method of burning and removing carbon while inserting an injection nozzle and injecting a gas containing oxygen, the total amount of attached carbon is grasped from the extrusion current value of a coke extruder, Patent Document 1 discloses an invention for determining injection conditions based on the total amount of adhered carbon. In this method, the relationship between the amount of adhering carbon and the extrusion current value is obtained in advance, and the gas blowing conditions are determined based on the current value for each extrusion. According to the method of Patent Document 1, when the extrusion current value is high, it is determined that the carbon adhesion is large, and the incineration is strengthened to cope with it.

However, there are cases where the extrusion current value does not necessarily reflect the carbon adhesion amount, for example, when the extrusion current value rises due to the presence of an undried portion due to insufficient carbonization time, or when the furnace wall has a large recess due to a brick defect, etc. Then, since the extrusion current value may increase even when there is no carbon, the scheme of “carbon adhesion is large when the extrusion current value is high” does not hold. In addition, since the relationship between the carbon adhesion amount and the extrusion current value differs depending on the wall state of each carbonization chamber, it is necessary to obtain this relationship for each carbonization chamber in order to execute the method of Patent Document 1, A large amount of data storage is required.
JP-A-61-231085

  The present invention solves the above-described conventional problems, does not impair the sealing function of the brick joints, does not cause damage such as spalling, and causes work and productivity hindrance in adverse environments. In addition, the present invention has been made to provide a method that enables moderate carbon incineration to reduce the extrusion resistance without having to accumulate a large amount of data even in a furnace wall having a brick defect or the like.

The present invention has been made to solve the above-mentioned problems. [1] The carbon adhering to the carbonization chamber of the coke oven is burned and removed while an injection nozzle is inserted into the carbonization chamber and a gas containing oxygen is injected. In the method, the correlation between the CO ₂ concentration of the combustion exhaust gas and the extrusion resistance value at the time of the next extrusion, and the CO ₂ concentration = X (%) when the extrusion resistance value is minimized are obtained in advance. When the CO ₂ concentration is lower than X (%), the gas blowing time at the next carbon incineration will be shortened, and when it is higher than X (%), the gas blowing time at the next carbon incineration will be extended. In a method for removing carbon adhering to a carbonization chamber of a coke oven by inserting an injection nozzle into the carbonization chamber and injecting the gas containing oxygen, the CO ₂ concentration of the combustion exhaust gas and the extrusion resistance during the next extrusion The correlation with the value and the extrusion resistance value are extreme. Previously grasped advance, when the CO ₂ concentration of the flue gas is less than X (%) is reducing the unit time per gas blowing amount of the next subsequent carbon burning of CO ₂ concentration = X (%) when the When X is higher than X (%), increase the amount of gas blown per unit time during the next carbon incineration. [3] Insert the injection nozzle into the carbonization chamber to deposit carbon adhering to the carbonization chamber of the coke oven. In the method of burning and removing while injecting a gas containing oxygen, the correlation between the CO ₂ concentration of the flue gas and the extrusion resistance value at the next extrusion, and the CO ₂ concentration when the extrusion resistance value is minimized = X (% ) And adjust the gas injection time during the next carbon incineration so that the CO ₂ concentration of the combustion exhaust gas becomes X ± 0.1 X (%). [4] In the carbonization chamber of the coke oven Insert the spray nozzle into the carbonization chamber. A method of burning off while injecting a gas containing oxygen Te, the flue gas of the CO ₂ concentration and the correlation between the extrusion resistance of the next extrusion, and extrusion CO ₂ concentration when the resistance value becomes minimum = X ( %) In advance, and by adjusting the amount of gas blown per unit time during the next carbon incineration so that the CO ₂ concentration of the combustion exhaust gas is X ± 0.1 X (%) The amount of adhesion is controlled to keep the wall surface smooth.

  According to the present invention, it is possible to appropriately control the incineration of carbon that adheres and grows in the coke oven carbonization chamber, and it is possible to smooth the carbonization chamber wall surface where there is a recess, and to reduce the extrusion resistance. Is. In this case, since the sealing performance of the brick joint portion is not impaired, the extrusion resistance can be reduced while avoiding leakage of generated gas and weakening of the carbonization chamber wall.

  Carbon that grows in the coke oven carbonization chamber grows excessively and forms a so-called bump shape, which increases extrusion resistance, and conversely, if it is excessively incinerated, it not only impairs the sealing function of the brick joints. Extrusion resistance can be increased by exposing the unevenness of the wall surface. Therefore, it is important to appropriately remove the carbon while appropriately controlling the carbon adhesion amount.

In a method of burning and removing carbon adhering to a carbonization chamber of a coke oven while inserting an injection nozzle into the carbonization chamber and injecting a gas containing oxygen, the CO ₂ concentration in the combustion exhaust gas is simply the amount of carbon attached. It is considered that this is not an index but an index representing the smoothness of carbon adhering to the wall surface of the carbonization chamber. In the carbonization chamber where the furnace wall has a significant dent, the carbon in the dent grows preferentially. This is because the furnace wall in the recess has the highest temperature due to its high thermal conductivity, and the possibility of carbon peeling during extrusion is low. Since the carbon grown in these dents has a low efficiency of being burned by the injected gas, even if a large amount adheres, it does not contribute much to the increase in CO ₂ concentration. However, so-called bump-like carbon that grows on a smooth part of the furnace wall has a high combustion efficiency even in a small amount, so that the CO ₂ concentration is remarkably increased. By measuring the CO ₂ concentration in the combustion exhaust gas, it is possible to estimate the smoothness of these carbonization chamber walls, leading to the idea of the present invention.

If the CO ₂ concentration in the combustion exhaust gas is higher than X (%), it can be judged that the carbon adhesion amount is excessive, and the carbon incineration amount can be increased by extending the gas injection time or increasing the gas injection amount per unit time. If the CO ₂ concentration in the combustion exhaust gas is lower than X (%), it can be judged that the amount of carbon adhering is too small, and the amount of carbon incineration can be determined by shortening the gas injection time or reducing the gas injection amount per unit time. Can be reduced. By always maintaining the optimum carbon adhesion amount by such a method, the optimum carbon incineration to the extent that the sealing performance of the brick joints is not impaired is made possible.

According to the method of the present invention, there is no need to obtain X (%) for each carbonization chamber, and adjustment is always performed with a constant target CO ₂ concentration as long as carbon incineration is performed using the same gas injection device and the same gas. Can be done.

After measuring the CO ₂ concentration of combustion exhaust gas, there are _two possible action means to adjust the incineration amount: the method of changing the gas injection time as described above and the method of changing the gas injection amount per unit time. It is done. There is no problem to use either as the carbon adhesion amount control means, but if the gas injection amount per unit time is changed, the CO ₂ concentration of the exhaust gas will inevitably change, so the CO at the time of carbon incineration will change. ₂ Concentration measurement data may become invalid. For this reason, it is more desirable to adopt a method of changing the gas injection time as the action means.

In implementing the present invention, the reason for setting the CO ₂ concentration target of exhaust gas to X ± 0.1 X (%) is as follows. That is, the exhaust gas CO ₂ concentration is a very delicate index, and it is very difficult to adjust it to the target value X (%). Therefore, the target value is set with a certain range, but if the target CO ₂ concentration is set to exceed X ± 0.1 X (%), the width is too large and it cannot be brought close to the minimum value of extrusion resistance. If an operation trouble such as combustion control abnormality occurs before extrusion, the carbon on the carbonization chamber changes due to separation of the adhered and grown carbon, and in the worst case, there is a risk of clogging. Therefore, the maximum allowable value of the exhaust gas CO ₂ target is set to X ± 0.1 X (%).

  In FIG. 1, 1 is a carbon incineration air blowing blower, 2 is an air injection nozzle for carbon incineration, and 3 is a coke oven carbonization chamber. Carbon deposits and grows in the carbonization chamber due to coal charging, carbonization, and carbonization. In order to incinerate and remove these carbons, an air injection nozzle is inserted every time extrusion is completed, and air is injected by a blower. The injected air incinerates carbon in the carbonization chamber and is discharged from the riser 4 as exhaust gas.

Although above structure is the same as the conventional, the riser 4 is in the present invention by inserting the sampling tube for CO ₂ concentration measurement, to measure the CO ₂ concentration of carbon burned from one implementation. Coal is charged into the carbon-burning carbonization chamber, and the current value when the coal is subjected to dry distillation and extrusion is recorded, and the relationship between the two is obtained.

For example, an example in which the CO ₂ concentration when the extrusion resistance value is minimized = X = 7.0% is shown. The relationship between the CO ₂ concentration and the extrusion current value in this example is shown in FIG. This time, we decided to adjust the incineration conditions with the goal of 7.0 ± 0.7 = 6.3% to 7.7%. Specifically, in the carbonization chamber that exceeded the target value upper limit of 7.7% by 1% or more, the carbon incineration time was extended by 10 seconds, and in the carbonization chamber that exceeded the target value lower limit of 6.3% by 1% or more, The amount of carbon incineration was optimized by shortening the carbon incineration time by 10 seconds.

The transition of the extrusion current value when this method is continued for one month is shown in FIG. By measuring the CO ₂ concentration in the combustion exhaust gas at each carbon incineration and reflecting it in the carbon incineration time at the next carbon incineration, the extrusion current value starts to decrease, about a month, compared to before applying this method It was possible to reduce the extrusion current value by 15%. The condition of the carbonization chamber before the application of this method was that there was no carbon adhesion before the application, and the dent of the wall of the carbonization chamber was exposed. Smooth carbon adhered to the entire surface of the wall, covering the dent of the carbonization chamber wall. That is, the reason why the extrusion current value was reduced in FIG. 3 was not that carbon incineration was strengthened, but carbonization was performed by incinerating the bumpy carbon in the smooth portion while growing carbon in the recesses of the carbonization chamber wall surface. This is due to the smoothing of the chamber walls.

It is sectional drawing which shows embodiment of this invention. It is a graph showing the correlation between the CO ₂ concentration and extruding current value. It is a graph which shows transition of an extrusion electric current value.

Explanation of symbols

1 Carbon incineration air blow blower 2 Carbon incineration air injection nozzle
3 Coke oven carbonization chamber 4 Coke oven riser 5 CO ₂ concentration analyzer

Claims (4)

In the method of burning and removing carbon adhering to the carbonization chamber of the coke oven while inserting an injection nozzle into the carbonization chamber and injecting a gas containing oxygen, the CO ₂ concentration of the combustion exhaust gas and the extrusion resistance value at the time of the next extrusion time correlation, and extrusion resistance beforehand grasped CO ₂ concentration = X (%) when the minimum, combustion CO ₂ concentration X (%) of the exhaust gas when lower the next time the carbon burning and The coke carbonization chamber adhering carbon combustion removal method characterized by extending the gas blowing time at the time of carbon incineration after the next time when the gas blowing time is shortened and higher than X (%). In the method of burning and removing carbon adhering to the carbonization chamber of the coke oven while inserting an injection nozzle into the carbonization chamber and injecting a gas containing oxygen, the CO ₂ concentration of the combustion exhaust gas and the extrusion resistance value at the time of the next extrusion time correlation, and extrusion resistance beforehand grasped CO ₂ concentration = X (%) when the minimum, combustion CO ₂ concentration X (%) of the exhaust gas when lower the next time the carbon burning and Reducing the amount of gas blown per unit time, and increasing the amount of gas blown per unit time at the time of carbon incineration after the next time when the amount is higher than X (%) . In the method of burning and removing carbon adhering to the carbonization chamber of the coke oven while inserting an injection nozzle into the carbonization chamber and injecting a gas containing oxygen, the CO ₂ concentration of the combustion exhaust gas and the extrusion resistance value at the time of the next extrusion The CO ₂ concentration when the extrusion resistance value becomes minimum and X (%) are grasped in advance and the next time so that the CO ₂ concentration of the combustion exhaust gas becomes X ± 0.1 X (%) A method for removing and adhering carbon in a coke carbonization chamber, wherein the amount of carbon deposition in the carbonization chamber is controlled by adjusting the gas blowing time during carbon incineration to keep the wall surface smooth. In the method of burning and removing carbon adhering to the carbonization chamber of the coke oven while inserting an injection nozzle into the carbonization chamber and injecting a gas containing oxygen, the CO ₂ concentration of the combustion exhaust gas and the extrusion resistance value at the time of the next extrusion The CO ₂ concentration when the extrusion resistance value becomes the minimum and X (%) are grasped in advance, and the next time so that the CO ₂ concentration of the combustion exhaust gas becomes X ± 0.1 X (%) A method for removing adhering carbon from a coke carbonization chamber, wherein the amount of carbon adhering in the carbonization chamber is controlled by adjusting the amount of gas blown per unit time during carbon incineration to keep the wall surface smooth.

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