JP4855206B2 - Method for removing adhering carbon from coking oven carbonization chamber - Google Patents

Description

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

In the carbonization chamber of the coke oven, 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 furnace wall-attached carbon lowers the furnace wall thermal conductivity as it grows on the furnace wall surface, and lowers the furnace productivity in order to reduce the effective area of the carbonization chamber. Further, the carbon adhering to the furnace wall causes so-called clogging that makes it impossible to extrude the coke, and periodic removal work is required. The following methods are well known as a method for removing the carbon adhering to the furnace wall.
(a) A method of pushing down manually using a spear-shaped jig having a length of 4 to 5 m.
(b) A method in which one or both of the furnace lids for coke extrusion and the riser are opened, and air is introduced into the carbonization chamber from the furnace lid portion by natural draft and burned.

  However, in the removal method by mechanical action (a), the carbon layer is completely detached from the furnace wall, so that the sealing function of the joint portion by carbon is impaired, and 3 to 4 workers are used. However, it is not preferable because heavy labor of 15 minutes or more is required under adverse conditions such as high heat and dust. In the method (b), the furnace wall in the vicinity of the air introduction part receives excessive cooling by passing cold air even after carbon is incinerated in the initial stage, and damage caused by spalling of the furnace body bricks, Adverse effects such as joint opening. In addition, oxygen used for combustion is about a fraction of that entering the carbonization chamber, and most of the air is discharged outside the furnace without contributing to combustion, so the amount of carbon combustion can be increased. Can not. For this reason, it takes a long time to remove carbon, resulting in production inhibition.

  Therefore, in order to solve these problems, Patent Document 1 discloses a method of burning and removing carbon by inserting an injection nozzle into a carbonization chamber and injecting a gas containing oxygen. In the invention of Patent Document 1, the total amount of attached carbon is grasped from the extrusion current value of the coke extruder, and the injection conditions are determined based on the total amount of attached 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. That is, 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, the extrusion current value may not necessarily reflect the carbon adhesion amount. For example, the extrusion current value increases even when the extrusion current value rises due to the presence of an undried carbonized portion due to insufficient carbonization time, or when no carbon is attached to the furnace wall having a large recess due to a brick defect or the like. Since it may rise, the scheme of “carbon adhesion is large when the extrusion current value is high” does not hold. Further, since the relationship between the carbon adhesion amount and the extrusion current value varies depending on the wall surface 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, which is very large. There is also a problem that it is necessary to accumulate data.
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 does not cause work or productivity hindrance in adverse environments. The present invention has been made in order to provide a method that enables an appropriate 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.

In order to solve the above-mentioned problems, the invention of claim 1 is directed to a carbonization of a coke oven in which carbon adhering to a carbonization chamber of a coke oven is burned and removed by inserting an injection nozzle into the carbonization chamber and injecting air. In the method for removing carbon adhering to the chamber, the correlation between the O ₂ concentration of the combustion exhaust gas and the extrusion resistance value at the time of the next extrusion, and the O ₂ concentration when the extrusion resistance value is minimized = X (%) are grasped in advance. When the O ₂ concentration of the combustion exhaust gas is higher than X (%), the air blowing time at the next and subsequent carbon incineration is shortened, and when it is lower than X (%), the air blowing at the next and subsequent carbon incineration. It is characterized by extending the time.

The invention of claim 2 made to solve the same problem is a coke oven in which carbon adhering to the carbonization chamber of the coke oven is burned and removed while inserting an injection nozzle into the carbonization chamber and injecting air. In the carbon combustion chamber removal method, the correlation between the O ₂ concentration of the combustion exhaust gas and the extrusion resistance value during the next extrusion, and the O ₂ concentration = X (%) when the extrusion resistance value is minimized are obtained in advance. When the O ₂ concentration of the combustion exhaust gas is higher than X (%), the air blowing amount per unit time at the next and subsequent carbon incinerations is decreased, and when it is lower than X (%), the next and subsequent carbon incinerations are performed. The air blowing amount per unit time is increased.

In any of the inventions, the next and subsequent carbon incinerations are adjusted so that the O ₂ concentration of the combustion exhaust gas is within the range of 0.9X to 1.1X, and the carbon adhesion amount in the carbonization chamber is controlled to smooth the wall surface. It is preferable to maintain. Further, it is preferable that the O ₂ concentration at which the extrusion resistance value is minimized is corrected for X (%) in consideration of the distance from the injection nozzle to the O ₂ concentration meter.

According to these inventions of the present application, focusing on the O ₂ concentration of the combustion exhaust gas as an index representing the smoothness of the carbon adhering to the furnace wall, the air blowing time at the next and subsequent carbon incineration, or the air blowing per unit time Adjust the amount. This makes it possible to properly control the incineration of carbon that adheres and grows in the carbonization chamber of the coke oven, and enables smoothing even on the wall surface of the carbonization chamber where there are recesses, thereby reducing the extrusion resistance value. is there. In this case, since the sealing performance of the brick joint portion is not impaired, the extrusion resistance can be reduced while avoiding the leakage of the generated gas and the weakening of the carbonization chamber wall.

  Carbon that grows in the carbonization chamber of a coke oven grows excessively and forms a bump shape, which increases extrusion resistance.Conversely, if it is excessively incinerated, it will not only impair the sealing function of the brick joint, Extrusion resistance may 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 removing carbon adhering to a carbonization chamber of a coke oven by inserting an injection nozzle into the carbonization chamber and injecting air, the O ₂ concentration of the combustion exhaust gas is not merely an indicator of the amount of carbon adhesion, but a carbonization chamber. This is considered to be an index representing the smoothness of carbon adhering to the furnace wall. That is, in the carbonization chamber where the recess of the furnace wall is remarkable, the carbon in the recess grows preferentially. This is because the temperature of the furnace wall in the recess is high because of 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 air, even if a large amount adheres, it does not contribute much to the decrease in O ₂ concentration. However, so-called bump-like carbon that grows on a smooth portion of the furnace wall has a high combustion efficiency even if it is a small amount, so that the O ₂ concentration is significantly reduced. The present invention has been completed based on the above idea that the smoothness of the carbonization chamber furnace wall can be estimated by measuring the O ₂ concentration in the combustion exhaust gas.

  FIG. 1 is a view showing an embodiment of the invention of claim 1, 1 is a coking chamber of a coke oven, 2 is an injection inserted into the carbonizing chamber 1 every time coke extrusion from the coking chamber 1 is completed. Nozzle. Each injection nozzle 2 is supplied with air from an incineration air blowing blower 3 to burn carbon. The injected air incinerates the carbon in the carbonization chamber 1 and is discharged from the riser 4 as exhaust gas.

In the present invention, a sampling tube for measuring the O ₂ concentration is inserted into the riser 4 to sample the combustion gas, and the O ₂ concentration analyzer 5 having pretreatment means and an O ₂ concentration meter is used to inject the O ₂ during carbon incineration. _Two concentrations are measured. Coal is charged into the carbonization chamber 1 where carbon incineration has been performed. The extrusion resistance value when the coal is subjected to dry distillation and extrusion is obtained as a current value of the driving motor, and the combustion exhaust gas is obtained by the arithmetic and control unit 6. Correlation between the O ₂ concentration and the extrusion resistance value at the time of the next extrusion, and the O ₂ concentration = X (%) when the extrusion resistance value is minimized. It is preferable to correct the O ₂ concentration X (%) value at which the extrusion resistance value is minimized in consideration of the distance from the injection nozzle 2 to the O ₂ concentration meter.

When the O ₂ concentration of the combustion exhaust gas is higher than X (%), it can be determined that the carbon adhesion amount is excessively small, and conversely when it is lower than X (%), it can be determined that the carbon adhesion amount is excessive. Therefore, in the invention of claim 1, when the O ₂ concentration of the combustion exhaust gas is higher than X (%), the air blowing time at the next and subsequent carbon incineration is shortened, and when it is lower than X (%), the next and subsequent carbons are reduced. Extend the air blowing time during incineration. In this way, it is possible to always maintain the optimum carbon deposition amount and to perform optimum carbon incineration to the extent that the sealing performance of the brick joints is not impaired.

Note that the amount of CO ₂ in the combustion gas is directly influenced by the amount of carbon combustion. However, as a result of experiments, there is almost no CO generation during carbon combustion, and the relationship CO ₂ concentration + O ₂ concentration = 21%. Therefore, it is possible to accurately grasp the amount of carbon combustion based on the O ₂ concentration. As the O ₂ concentration meter, for example, a zirconia sensor can be used. This sensor is strong against vibration as mounted on an automobile and can be used as it is exposed, so that visual inspection is easy and the maintenance load is small. There is. In these respects, the practical value of the present invention is great.

In the invention of claim 1 described above but changing the air blowing time for subsequent carbon incineration next by the O ₂ concentration of the flue gas, in the invention of claim 2, the O ₂ concentration in the flue gas X (%) When the temperature is higher than that, the air blowing amount per unit time at the next and subsequent carbon incineration is decreased, and when it is lower than X (%), the air blowing amount at the next and subsequent carbon incineration is increased. The amount of carbon combustion can also be adjusted by the method of claim 2. In any of the inventions, it is not necessary to obtain the O ₂ concentration = X (%) when the extrusion resistance value is minimized for each carbonization chamber, and the same gas injection device and the same gas (air) are used for carbon. As long as the incineration is performed, adjustment should always be made with a constant target O ₂ concentration.

As described above, the means for adjusting the carbon incineration amount includes the method of claim 1 for changing the air blowing time and the method of claim 2 for changing the air blowing amount per unit time. There is no problem even if this method is used. However, when the method of claim 2 is used, the O ₂ concentration in the exhaust gas is inevitably changed, so that the O ₂ concentration measurement data at the time of carbon incineration may become invalid. In this respect, the method of claim 1 is more preferable.

In the case of carrying out the inventions of claims 1 and 2, as described in claims 3 and 4, the next and subsequent carbons are set so that the O ₂ concentration of the combustion exhaust gas falls within the range of 0.9X to 1.1X. It is preferable to keep the wall surface smooth by adjusting the air blowing time during incineration and controlling the amount of carbon adhering in the carbonization chamber. The O ₂ concentration in the exhaust gas 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. However, if the target value is set to exceed X ± 0.1X (%), the width is too large to approach the minimum value of the extrusion resistance value. When an operation trouble such as an abnormality in the combustion apparatus occurs before extrusion, the state of the carbonization chamber wall surface changes due to separation of the adhered and grown carbon, and in the worst case, there is a risk of clogging. Therefore, it is preferable to set the target value within the range of X ± 0.1X (%).

When the carbon adhesion amount is controlled using such a method, if the carbon adhesion amount in the carbonization chamber 1 is too small, the O ₂ concentration is less than X (%) even immediately after the start of carbon incineration. There may not be. For such a case, for example, “If the O ₂ concentration> X (%) after a lapse of a predetermined number of seconds after the start of the carbon incineration, the carbon incineration is stopped at that time” to be programmed in advance. Is preferred. The time for determining whether to continue or stop the carbon incineration is set individually depending on the characteristics of the carbon incinerator.

Similarly, when petal-like carbon or convex carbon is excessively grown in the carbonization chamber 1, the O ₂ concentration does not rise to X (%) even if carbon incineration is performed for a considerable time, and as a result In some cases, carbon incineration may be continued for a long time that would impede production. For such a case, for example, “if the O ₂ concentration is less than X (%) after a lapse of a predetermined number of seconds after the start of the carbon incineration, the carbon incineration is stopped at that time” to be programmed in advance. Is preferred. The time for determining whether to continue or stop the carbon incineration is set individually depending on the characteristics of the carbon incinerator.

Carbon incineration was performed using the apparatus shown in FIG. The relationship between the extrusion current value and the O ₂ concentration of the combustion exhaust gas is as shown in the graph of FIG. 2, and the O ₂ concentration when the extrusion resistance value is minimized was 14.0%. Therefore, the incineration conditions were adjusted with a target of 14.0 ± 1.4% = 12.6 to 15.4%. Specifically, the carbon incineration time is extended by 10 seconds in the carbonization chamber below the target value lower limit of 12.6%, and the carbon incineration time is increased in the carbonization chamber higher than the target upper limit of 15.4%. By shortening by 10 seconds, the carbon incineration amount was optimized.

The transition of the extrusion current value when the above method is continued for one month is shown in FIG. By measuring the O 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, and the extrusion current value in about one month compared to the conventional one Can be reduced by 15%. In the conventional carbonization chamber, there was no carbon adhesion, and the dent of the carbonization chamber wall was exposed. On the other hand, after applying the method of the present invention for one month, smooth carbon adhered to the entire wall surface. It was in a state of covering the dent of the carbonization chamber wall. That is, the reason for lowering the extrusion current value in FIG. 3 is not to strengthen the carbon incineration, but by incinerating the bumpy carbon in the smooth part while growing the carbon in the recess of the carbonization chamber wall surface, This is because the carbonization chamber wall is smoothed.

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

Explanation of symbols

1 blowing carbonization chamber 2 injection nozzle 3 incineration air blower 4 riser 5 O ₂ concentration analyzer 6 calculation control unit

Claims (5)

The carbon attached to carbonization chamber of coke oven, the deposited carbon burnoff method of the coking chamber of the insert the injection nozzle to the carbon reduction chamber coke oven burning off while injecting air, following the O ₂ concentration in the combustion exhaust gas When the correlation with the extrusion resistance value during extrusion and the O ₂ concentration = X (%) when the extrusion resistance value is minimized are grasped in advance, and the O ₂ concentration of the combustion exhaust gas is higher than X (%) Adhesive carbon in the coking oven carbonization chamber characterized by shortening the air blowing time at the next and subsequent carbon incineration, and extending the air blowing time at the next and subsequent carbon incineration when lower than X (%) Combustion removal method. The carbon attached to carbonization chamber of coke oven, the deposited carbon burnoff method of the coking chamber of the insert the injection nozzle to the carbon reduction chamber coke oven burning off while injecting air, following the O ₂ concentration in the combustion exhaust gas When the correlation with the extrusion resistance value during extrusion and the O ₂ concentration = X (%) when the extrusion resistance value is minimized are grasped in advance, and the O ₂ concentration of the combustion exhaust gas is higher than X (%) The coke oven is characterized in that the amount of air blown per unit time at the next and subsequent carbon incinerations is reduced, and when it is lower than X (%), the amount of air blown per unit time at the next and subsequent carbon incinerations is increased. Carbon combustion chamber removal method. Adjust the air blowing time at the next and subsequent carbon incineration so that the O ₂ concentration of the combustion exhaust gas is in the range of 0.9X to 1.1X, and control the carbon adhesion amount in the carbonization chamber to smooth the wall surface The method for removing carbon from adhering carbon in a carbonizing chamber of a coke oven according to claim 1, wherein the method is maintained. Adjust the air blowing amount per unit time at the next and subsequent carbon incineration so that the O ₂ concentration of the combustion exhaust gas is in the range of 0.9X to 1.1X, and control the carbon adhesion amount in the carbonization chamber 3. A method for burning and removing adhering carbon in a carbonizing chamber of a coke oven according to claim 2, wherein the carbon is kept smooth. 5. The O ₂ concentration X (%) at which the extrusion resistance value is minimized is corrected in consideration of the distance from the injection nozzle to the O ₂ concentration meter. 6. A method for removing carbon adhering to a coking oven carbonization chamber.

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