JP5962924B2 - Coke oven operation method - Google Patents

Description

  The present invention relates to a method for operating a coke oven, and in particular, proposes a method for operating a coke oven that can effectively prevent push-up clogging without reducing the amount of coal as much as possible in the carbonization chamber.

  In general, a coke oven is a furnace for producing coke by dry distillation of coal charged into a carbonizing chamber R with heat supplied from an adjacent combustion chamber, as shown in FIG. Coal charged into the carbonization chamber becomes red hot coke (coke cake) at about 1000 ° C. by heating and dry distillation for about 15 to 24 hours. Thereafter, the furnace lids D1 and D2 installed at both ends in the length direction (furnace length direction) of the carbonizing chamber of the coke oven are opened and opened, and the ram 8 of the extruder is opened from the opening on the machine side (MS side). , And the coke cake Cc in a red hot state in the furnace is pushed in, so that the coke cake is discharged out of the furnace through the opening on the other discharge side (coke side: CS side) and cooled to obtain product coke.

  In the above-mentioned operation of the coke oven, when the coke cake after carbonization in the carbonization chamber is discharged out of the furnace using an extruder, the coke cake produced depending on the condition of the furnace wall and the condition of carbonization (shrinkage) of the coal. There is a case where a phenomenon called “clogging” occurs in which the discharge becomes difficult to block. When this clogging occurs, there is a concern about the influence on the coke productivity decline due to the expansion of the damage to the furnace wall and the change of the production schedule. Therefore, improving the extrudability of the coke cake is extremely important in the operation of the coke oven.

  By the way, the factors governing the extrudability of the coke cake in the carbonization chamber include the amount of shrinkage in the furnace width direction of the coke cake after dry distillation, the amount of deformation of the coke cake during extrusion, the state of the furnace wall (such as deposits and collapse), The stability of the coke properties can be considered. It is known that the coke cake after dry distillation generally contracts in the furnace width direction and the furnace height direction due to the detachment of the internal volatile components. Thereby, for example, a gap is generated between the furnace wall and the coke cake side wall surface, and smooth extrusion becomes possible. However, as mentioned above, the trouble of clogging often occurs. The main cause is when the resistance between the coke cake and the furnace wall and hearth increases. Therefore, the extrusion of the coke cake becomes easier as the amount of shrinkage of the coke cake increases (the gap increases).

  In this regard, when the coke cake being extruded is compressed and compressed by the ram of the extruder, the coke cake tends to spread in the furnace width direction not directly receiving the compression load (see, for example, Non-Patent Documents 1 and 2). When it comes into contact with the furnace wall, it receives a large resistance (load) and causes clogging. It is known that such a load generated when the coke cake contacts the furnace wall is greatly affected by cracks existing in the coke cake.

  Coke cake clogging in the carbonization chamber thus occurs is a balance between the amount of shrinkage of the cake in the furnace width direction and the extent of expansion of the cake in the furnace width direction during extrusion, that is, coke cake and furnace wall. Most of the cases are caused by the resistance between the two.

  From these viewpoints, various proposals have been made regarding the extrudability of coke cake. For example, in Patent Document 1, in the blending of multiple brands of raw coal, the expansion pressure of each single coal is estimated in advance, and from the obtained expansion pressure of each single coal and the blending ratio of each single coal, We have proposed a method that averages the expansion pressure of charcoal and adjusts the blending ratio and blending brand so that it is below the allowable limit pressure of the coke oven. Moreover, in patent document 2, in the mixing | blending process of multiple brand raw material coal, it estimates from the average reflectance of the vitrinite of each simple coal which comprises blended coal, and the average reflectance of the blended coal calculated | required based on a blending rate. We propose a method for estimating the extrudability of coke cake using the shrinkage of coke.

  By the way, as for the extrusion failure due to the clogging of the coke cake, in addition to the above-mentioned clogging due to the resistance between the coke cake and the furnace wall, the coke cake rushes upward (toward the ceiling) during extrusion and eventually reaches the ceiling. There is an example (push-up clogging).

  Conventionally, especially for the clogging phenomenon due to the former side wall, an extrusion current value of an extruder (ram) representing resistance at the time of extruding coke cake is used as one of management indexes of this phenomenon. For example, when clogging occurs due to deformation or collapse of furnace wall bricks, as shown in FIG. 2, the previous extrusion current value is larger than the current value during normal extrusion (previous). It is normal to have a sign of. However, in the case of the so-called clogging of the so-called coke cake, as shown in FIG. 3, it is normal that a phenomenon corresponding to a sign of clogging, that is, an increase in the extrusion current value due to an increase in frictional resistance with the furnace wall does not appear. .

  Causes of the above-mentioned clogging that occurs when the top of the coke cake comes into contact with the ceiling include furnace wall brick overhang on the coke side, carbon adhesion to the wall, growth, or coke cake destruction due to coke fine graining, etc. The cause of this can also be considered, but the actual cause is still unclear. Therefore, a technique for predicting the clogging due to the bulge (crushing) at the top of the coke cake that appears at the time of extrusion has not been established. Therefore, in the current operation of the coke oven, the amount of coal charged is controlled in advance in order to allow the coke cake to rise, and a sufficient space distance is secured between the top of the coke cake and the ceiling of the coking chamber. The actual situation is to respond by doing.

  In this regard, as a method of operating the coke oven to eliminate the above-mentioned clogging, a method of lowering the charging height of coal in the carbonization chamber at the coke side (for example, refer to Patent Document 3), A method of lowering the charging height on the machine side (for example, see Patent Document 4) has been proposed.

JP-A-6-212164 JP 2006-249174 A JP 2008-1839 A JP 2005-255697 A

Nishioka et al .: “Coke Circular”, Vol. 35, 1986, p. 21-28 Watanabe et al .: “Iron and Copper”, Vol. 84, 1998, p. 165-170

  However, in the method of operating a coke oven disclosed in Patent Literature 3 and Patent Literature 4 described above, even though the clogging can be prevented, the amount of coal charged into the carbonization chamber of the coke oven is reduced, There was a problem that coke production decreased.

  Therefore, the present invention specifies a carbonization chamber that is highly at risk of occurrence of push-up clogging, and operates a coke oven that can effectively prevent push-up clogging without reducing the amount of coal as much as possible in the carbonization chamber. The purpose is to propose a method.

As a result of diligent research to solve the above-mentioned problems of the prior art and to achieve the above-mentioned object, the inventors have found that the coke cake is provided in the carbonization chamber and is located closest to the coke side. the height of the coke cake immediately below the coal outlet was measured to calculate the amount the push-up of the coke cake in its position with respect to the carbonization chamber of the push-up amount is more than 400 mm, the next coal charging Nyutoki carbide chamber In the carbonization chamber in which there is a portion where the distance from the coke cake before extrusion to the ceiling is 1000 mm or less, the top level of the coke cake under the coal throat near the coke side is the other carburetor. Operation method of coke oven characterized by charging coal so as not to be more than 100mm higher than the average value of the top level of the lower coke cake And found that it is effective to adopt, was led to the development of the present invention.

In the method of operating a coke oven according to the present invention configured as described above,
(1) The measurement is performed using a non-contact distance meter,
(2) The measurement with the non-contact distance meter should be carried out using a heat-resistant microwave distance meter that can be transported;
(3) The amount of push-up is a difference between the coke cake height before the start of extrusion and the maximum height of the coke cake being extruded,
However, this is considered to be a more preferable solution.

  According to the method of operating a coke oven of the present invention, a carbonization chamber having a high risk of occurrence of push-up clogging is identified in advance, and in the carbonization chamber, push-up clogging is effectively prevented without reducing the amount of coal as much as possible. Can operate a coke oven.

It is sectional drawing which shows the general state in the coke oven carbonization chamber before extrusion. It is a figure which shows the example of the extrusion electric current value during coke cake extrusion at the time of the normal (from the side wall) clogging occurrence. It is a figure which shows the example of the extrusion electric current value during coke cake extrusion at the time of pushing-up clogging generation | occurrence | production. (A), (b) is explanatory drawing of the method of measuring coke cake height according to this invention method, respectively. (A), (b) is a schematic diagram of the measuring apparatus for measuring the coke cake height used by this invention, respectively. It is sectional drawing of the microwave rangefinder which is a specific example of the measuring apparatus used by this invention. It is a graph which shows the relationship between a coke cake level difference and the amount of pushing up of coke cake. It is an example of measuring the coke cake height during coke extrusion by a microwave rangefinder.

  The present invention is different from the so-called “clogging”, which is different from the conventional “clogging”, which is an obstacle occurring in the furnace width direction due to deformation and collapse of the inner wall and bottom surface of the coke oven, adhesion of various components, growth thereof, and the like. It proposes a method for preventing obstacles that occur in the high direction, in particular between the ceiling, i.e. "clogging up". That is, in order to eliminate clogging, the furnace side wall surface and the bottom surface of the furnace, which are the cause of the clogging, are effective. However, the above-mentioned clogging is not eliminated by the above processing on the side wall of the furnace and the bottom surface of the furnace. . According to the knowledge of the inventors regarding this point, it is effective to control the coal charge level, in particular, to control the coal level of the most coke side side coal inlet to below the coal level of other coal outlets. it is conceivable that. In this sense, push-up clogging, which is a problem to be solved by the present invention, and conventional clogging are clearly different concepts.

  Hereinafter, an effective extrusion method for preventing such push-up clogging will be described. In the present invention, it has become a point to grasp (measure) the dynamic fluctuation (swelling) of the coke cake height in the red hot state during extrusion by the extruder at any time (continuous or intermittent).

  First, means for measuring the coke cake height (top) will be described with reference to FIGS. In the coke oven, normally, 4 to 5 (in the illustrated example, 4) coal inlets for charging coal are provided in the furnace ceiling. Generally, during operation of the coke oven, that is, during the dry distillation of coal and immediately after the dry distillation, a lid is attached to these coal charging ports so that outside air does not enter.

  On the other hand, in the present invention, in order to measure the height of the coke cake, immediately after the end of dry distillation, the charging lids are removed from all the coal inlets, and a non-contact type distance meter described in detail later is installed there. Then, measure the height of the coke cake at the bottom of all the coal charges, and close the charging lid after the measurement. Next, the place to be measured, in the present invention, the charging cover on the most coke side is removed, and a non-contact type distance meter is installed there, and the coke cake height at this position is measured. Conventionally, the depth from the top of the furnace to the top of the coke cake was measured by removing the lid of the coal charging port and inserting a rod from above to obtain the coke cake height.

  However, such work is not only performed in a poor working environment under a high heat atmosphere, but also has a problem that the measurement value itself is inaccurate due to individual differences. Moreover, it is actually difficult to measure at least continuously the fluctuations in the height of the coke cake that is moving through the furnace by extrusion. Therefore, in the present invention, in order to measure the height of the coke cake in a non-contact and continuous manner or at predetermined intervals, the measurement is performed using a measuring apparatus having a microwave distance meter as a suitable example.

4 (a) and 4 (b) show a state where the transporting (moving) heat-resistant measuring device used in the present invention is installed in the coal charging port G, and FIGS. 5 (a) and 5 (b) show the measurement. is a diagram showing the appearance of the device which is one embodiment of a microwave distance meter M (M 1 _{~M 4),} FIG 6 is a partial cross-sectional view of a microwave rangefinder M. The measuring apparatus shown in these drawings, that is, the microwave distance meter M, needs to have a heat resistant structure because the room temperature in the coke oven carbonization chamber R usually rises to about 1000 ° C.

  Therefore, the illustrated microwave rangefinder M has a structure in which most of the portion facing the inside of the furnace from the coal charging port G is provided with a heat insulating bottom plate 1 in order to prevent radiant heat received from the inside of the carbonization chamber R. It has become. Specifically, it has a configuration in which a cylindrical dome-shaped microwave generator main body 2 is installed on the heat insulating bottom plate 1, and mainly the lower portion of the microwave generator main body 2, more preferably substantially the entire heat insulating sheet. 3 to cover the whole and shield the heat. This is because the entire measuring device can be protected from the flame rising from the inside of the carbonizing chamber R and the high heat dust through the coal opening G.

  The microwave generator body 2 includes a microwave generator / receiver 4a inside the top of the dome 2a and a sensor 4b outside the top of the dome 2a. The sensor 4b includes a controller 5 and A computer 6 is attached.

  The dome portion 2a of the microwave generator body 2 is provided with a cold air intake hole 2h as necessary so that the cold wave can be sent into the dome portion 2a to cool the microwave generator / receiver 4a. It is preferable to do. Further, the heat insulating bottom plate 1 is provided with a plurality of adjusting bolts 7 for adjusting the height and the level, and further, although not shown, a moving carrier may be provided.

  As described above, the sensor 4b of the heat-resistant measuring device applicable to the implementation of the method of the present invention is connected to an external controller 5 via a cable, and further connected to a terminal such as a computer (PC) 6. Thus, it is possible to monitor the change over time of the distance to the top of the coke cake Cc in the carbonization chamber R and the temperature in the dome of the measuring device. In particular, the instantaneous value of the distance dt between the top of the coke cake Cc and the measuring device can be measured accurately and continuously without contact by the microwave irradiated from the microwave generator / receiver 4a.

Thus, by measuring the coke cake _CC top surface height (hcs, hcm) before and after extrusion using the microwave distance meter M, finally the coke cake directly under the coal loading port G A push-up amount (L) is obtained.

  Hereinafter, an example of a method for obtaining the push-up amount (L) will be described with reference to FIGS. 4 (a) and 4 (b). The specific calculation procedure is not limited to the method described below.

  Now, when the ceiling height in the carbonization chamber is (H), the coke cake height after dry distillation (before extrusion) is (hcs), and the maximum height (hcm) of the coke cake during extrusion is given, The amount (L), that is, the height of the crushing is given by [hcm-hcs], and the height of the coke cake Cc that can be pushed up, that is, the margin height (d) to the bottom of the ceiling is [H-hcm]. Given in. At this time, the coke cake height hcs after the carbonization can be determined by measuring the coke cake height at all the coal charging ports immediately after the carbonization, and the average value thereof can be the hcs value. In addition, when coal is charged into the carbonization chamber and dry distillation is performed, measurement at some of the charging ports can be omitted. Further, as shown in FIG. 4 (b), the coke cake rushes easily at the portion near the pushing ram of the coke cake, and hardly occurs at the portion away from the ram (see the measurement example in FIG. 8). For example, among the coke cake heights measured continuously at the inlet closest to the coke side, the average of the coke cake heights measured in the first half of the extrusion operation can be substituted as hcs. When hcs is estimated by the simplified method as described above, a correlation between an average value when measured at all the coal inlets and a value estimated by the simplified method is obtained in advance, and based on the correlation. It is more preferable to estimate hcs.

  Hereinafter, the measurement procedure of the coke cake height implemented by the method of the present invention will be described. In the measurement, after the end of carbonization, before the extrusion, first, the one at the measurement position is removed from the charging lids closing the coal-filling ports G existing on the carbonization chamber ceiling of the coke oven, and the microwave distance A total M is installed on the coal opening G. And a microwave is irradiated toward the coke cake Cc top surface. In this manner, the distance hcs of the coke cake height (from the furnace bottom to the coke cake top surface) is measured. Thereafter, in order to extrude the coke cake, the respective furnace lids of the machine side (MS) and the coke side (CS) are opened, the ram 8 of the extruder is pushed forward, and the extrusion of the coke cake Cc is started. At this time, in order to prevent the hot air in the carbonizing chamber R from blowing out from the coal opening G, the removal of the charging lid and the installation work of the microwave distance meter M to the coal charging port G are performed before opening the furnace lid. It is desirable to do.

  Thereafter, as shown in FIG. 5, the microwave distance meter M is preferably partially or entirely covered with a heat insulating sheet 3 for protection. In addition, when the thermal insulation sheet 3 coating alone is still insufficient, protection is enhanced by spraying an amorphous refractory material on the thermal insulation sheet 3 as necessary.

  Next, the extrusion ram 8 of the extruder on the machine side (MS) is pressed against the rear end face of the coke cake on the MS side, further pushed forward, and finally discharged from the coke side (CS) side to the outside of the furnace.

  The height of the coke cake top surface measured by the microwave rangefinder M during the above-described extrusion operation is measured continuously or at predetermined time intervals, that is, intermittently, at the coke cake height (hcm) immediately below the coal charging port G. The measured values are sequentially transmitted and recorded on a recording medium such as a PC or a data logger. In addition, when the coke cake Cc is pushed out, if the ram head of the extruder touches the coke cake and wants to match the time at which the extrusion actually starts and the measurement start time, the operator operating the extruder and the measurer will be wireless. It is desirable to use and communicate with each other.

  In proposing the operation method of the coke oven of the present invention, the inventors measured the data of the coke cake height before extrusion and the coke cake push-up amount during extrusion in 20 or more kilns using the above measurement method. did. During this measurement, push-up clogging did not occur, but it was found that the coke cake was always pushed up during extrusion. In addition, he noticed that the higher the coke cake level near the coke outlet closest to the coke side, the higher the amount of thrust.

  The present invention has been obtained based on the above knowledge, and when coke cake obtained by subjecting coal to a carbonization chamber of a coke oven and subjected to dry distillation treatment is extruded, the coke cake is discharged without causing clogging. In the method of operating the coke oven, the height of the coke cake is measured immediately below the coal opening provided in the carbonization chamber and closest to the coke side when the coke cake is extruded, and the coke at that position is Calculate the cake push-up amount, and for the carbonization chamber where the push-up amount exceeds 400 mm, the top level of the coke cake below the coal throat near the coke side at the next coal charge is It is characterized in that coal is charged so as not to be higher by 100 mm or more than the average value at the top level of the lower coke cake.

  In the present invention, a carbonization chamber having a push-up height exceeding 400 mm at the time of extrusion was assumed as a carbonization chamber having a high risk of occurrence of push-up clogging. The reason for this is that, according to the knowledge of the inventors, in the carbonization chamber having a push-up height of 400 mm or less, push-up clogging hardly occurs at the next dry distillation, and therefore, management of the charging level is unnecessary.

  The average value of the coke cake height hcs1 under the coal charging port closest to the coke side and the coke cake height under the other coal charging ports in a plurality of Karl still type coke ovens that satisfy the conditions of the carbonization chamber. The difference with hcs-av was taken and the relationship with the amount of push-up L was investigated. The survey results are shown in FIG. From the results shown in FIG. 7, the coke cake height hcs1 under the charcoal throat closest to the coke side is more than the average value hcs-av of the coke cake height under the charcoal throat near the other machine side. It has been found that when the height is increased by 100 mm or more, the push-up amount rapidly increases to 800 mm or more. Since the distance from the coke cake before extrusion to the ceiling is about 1000 mm, it is considered that the risk of pushing-up clogging becomes higher when pushing up 800 mm or more. In addition, in order to prevent clogging and the like, when performing “reduction” to reduce the amount of coal charged into the carbonization chamber below a predetermined amount as proposed in Patent Document 3 and Patent Document 4, before extrusion. Since the distance from the coke cake to the ceiling becomes large, in such a case, the push-up clogging hardly occurs. That is, the method of the present invention is particularly effective when there is a portion in the carbonization chamber where the distance between the coke cake before extrusion and the ceiling is 1000 mm or less.

  Here, the reason why the push-up amount increases when the coke cake level at the lower part of the coal loading mouth closest to the coke side is high is not clear, but the inventors consider as follows. As an example, the coke cake has a width of about 40 cm, a height of about 6 m, and a length of about 15 m. Since the coke cake is extruded by an extruder, the weight of the coke on the side opposite to the extruder (coke side) is heavy or the resistance is large. If it is difficult to move, the coke cake itself will be difficult to move. However, since the extrusion ram continues to the inside of the furnace during that time, the amount of coke pushed by the extrusion ram rises to the upper space. In general, in the portion closest to the coke side, the furnace wall bricks are greatly damaged and the extrusion resistance is likely to increase.In addition, if the coke temperature decreases due to heat dissipation near the kiln opening or deterioration of the furnace body, Since coke heat shrinkage is insufficient and extrusion resistance tends to increase, a slight increase in coke level is thought to have a significant effect on the coke cake push-up phenomenon.

  Based on this knowledge, control the coal charge level so that the coke cake level near the coke side closest to the coke side is not more than 100 mm higher than the average value of the coke cake level under other coal charge openings. Went. Specifically, since the vertical coke shrinkage of the Carl Still type coke oven in which the experiment was conducted was about 14%, the difference in the charged coal level was 115 mm or less, that is, the most coke side side. It was decided to manage the coal level immediately after charging under the coal loading port so that it does not become 115 mm or more higher than the average value of the coal level under the other charging port. As a result, as shown in Table 1 below, the occurrence rate of push-up clogging was successfully reduced from 1.2% to 0.3%, and the effectiveness of the present invention could be confirmed.

  In addition, about the threshold value (115 mm or more in the said example) of a coal charging level, since shrinkage | contraction rate changes with vertical directions by the operating condition of a coke oven, it is desirable to set according to each coke oven.

  The method for operating a coke oven according to the present invention can be applied not only to prevent the coke cake from being pushed up, but also to prevent clogging due to abnormalities in the side wall and bottom surface of the carbonization chamber, or changes in the composition.

Cc Coke cake D1, D2 Furnace G Charcoal inlet H Ceiling height M Microwave distance meter R Carbonization chamber 1 Heat insulation bottom plate 2 Microwave generator body 2a Dome part 2h Cold air intake hole 3 Heat insulation sheet 4a Microwave generator / receiver 4b Sensor 5 Controller 6 Calculator 7 Adjustment bolt 8 Extruder ram

Claims (4)

In the method of operating the coke oven for discharging the coke cake without causing push-up clogging when extruding the coke cake obtained by carbonizing the coke oven and charging it with carbonization,
At the time of coke cake extrusion, the height of the coke cake is measured just below the coal throat near the coke side provided in the carbonization chamber, the amount of the coke cake pushed up at that position is calculated, and the push up For the carbonization chamber whose amount exceeds 400 mm,
At the next coal charge, in the carbonization chamber, there is a portion where the distance from the coke cake before extrusion to the ceiling is 1000 mm or less. A method for operating a coke oven, wherein coal is charged so that a top level does not become 100 mm or more higher than an average value of a top level of a coke cake under another coal loading port.   The method for operating a coke oven according to claim 1, wherein the measurement is performed using a non-contact distance meter.   The method for operating a coke oven according to claim 2, wherein the measurement by the non-contact distance meter is performed using a heat-resistant microwave distance meter that can be transported.   The method of operating a coke oven according to any one of claims 1 to 3, wherein the push-up amount is a difference between a coke cake height before starting extrusion and a maximum height of the coke cake being extruded.

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