JP4337578B2 - Coke production method - Google Patents

Description

  The present invention relates to a method for producing coke, and in particular, by adjusting the particle size of the charged coal over the length of the coke oven, an advantageous increase in coke shrinkage at least in the vicinity of the coke outlet on the coke discharge side is provided. Therefore, when extruding coke from a coke oven, smooth extrusion without clogging is to be realized.

  In the coke oven of the chamber furnace type, the carbonization chamber into which the coal is charged is the side from which the coke is discharged from the side where the extruder rack for extruding the coke enters (also called the machine side, M / S) (the coke). The distance between the furnace walls (hereinafter referred to as the furnace width) gradually increases toward the side (also referred to as C / S). This is because coke discharged from carbonization is easily discharged, but the length of the coke oven ranges from 12 to 13m to 17 to 18m. (Increase) is only about 40-80mm.

  By the way, in recent years, the age (age) of the coke oven has become the most aging and has been nearly 40 years, and countermeasures against aging of each company have become an important issue. As a coke oven ages, as a matter of course, deformation of the furnace body and deterioration of incidental facilities become more prominent. In particular, the condition of the furnace wall in the coke oven is that the brick spalling, the thermal expansion and the furnace caused by the thermal stress caused by the cooling action by coal charging and carbon burning as the years pass Overhang of bricks due to unbalanced tightening and wear of bricks due to coke discharge work become conspicuous.

  In particular, the state of the coke discharge side (C / S) furnace wall in the furnace length direction of the coke oven is an empty kiln for carbon baking and the above-mentioned brick overhang and wear (C / S passes through the entire amount of coke) Therefore, the rough surface of the brick (unevenness) due to the longest contact time with coke) is remarkable. When the unevenness of such bricks becomes large, the load at the time of discharging the coke increases and the coke is clogged. If C / S clogging occurs in the early stage of coke discharge, the entire amount of coke cannot be discharged from the carbonization chamber. Therefore, a great deal of labor is required for the subsequent processing, which is serious in the operation of the coke oven. Adversely affect.

Further, the temperature distribution of the combustion chamber is set to have a temperature gradient so that the temperature increases from M / S to C / S so as to match the taper described above. The temperature of the brick wall surface of the furnace wall of S and C / S usually tends to decrease. For this reason, poor carbonization due to dry distillation often occurs on the side of the kiln. As a result, the amount of shrinkage in the furnace width direction of coke produced after dry distillation becomes insufficient, which is one of the causes of clogging.
Of course, for the unevenness of the furnace wall, the brick surface is smoothed by spraying, spraying or the like, and the temperature control of the combustion chamber is performed so that carbonization defects do not exceed. However, even when the C / S furnace wall is uneven or when carbonization failure occurs, the shrinkage amount of the C / S coke in the furnace width direction can be increased compared to other parts. If possible, coke can be discharged smoothly without causing clogging. Similarly, if the amount of contraction in the furnace width direction of coke at M / S can be increased, the discharge of coke becomes even smoother.

Conventionally, as a method of charging carbon materials having different properties in the length direction of the coke oven, a method of charging formed charcoal to the bottom of the kiln mouth side (both sides in the furnace length direction) has been proposed (for example, Patent Documents). 1).
However, in order to cause such segregation in the carbonization chamber, as described in the above-mentioned Patent Document 1, it is necessary to preliminarily form charcoal on the bottom of the hopper on the side of the kiln of the charcoal vehicle. In the above-mentioned patent document 1, since this packing method is not mentioned, it is not possible to say clearly, but first, after charging coal to the bottoms of both hoppers on the kiln entrance side, the blended coal is to be stacked on all hoppers. Conceivable.
If that is the case, it is necessary to prepare equipment for loading coal into a charcoal vehicle in a separate system from the usual coal blending equipment, which requires installation of large-scale equipment and capital investment. Become.

In addition, regarding the blending and charging of coal using particle size segregation, a coke strength stabilization technique using a difference in properties according to the particle size before pulverization of certain special coal brands has been proposed (see, for example, Patent Document 2). ).
However, this method is a technique in the yard pile and coal tank hopper before loading into the coal tower, and in the coal tower, the unique brand and other blended coal are mixed uniformly. Conditionally desirable.
Therefore, this method cannot selectively increase the coke shrinkage of the kiln (particularly C / S).

JP-A-6-212162 (Claims) JP-A-3-263488 (Claims)

  The present invention advantageously solves the above-mentioned problems of the prior art, with a slight improvement in the equipment for loading on the coal tower, and using the same blended coal as before, C / S and as required. Thus, an object of the present invention is to propose a coke production method that can increase the shrinkage amount of the M / S coke in the furnace width direction, and as a result, can smoothly extrude the coke from the coke oven.

Now, as a result of intensive studies to achieve the above object, the inventors adjust the grain size of the coal to be charged over the length of the coke oven even when using a normal blended coal. Specifically, by reducing the particle size of coal charged in C / S and M / S, the amount of shrinkage in the furnace width direction of coke increases, and as a result, coke can be discharged smoothly. I got the knowledge.
The present invention is based on the above findings.

That is, the gist configuration of the present invention is as follows.
(1) In the coal tower that supplies coal to the coal charging vehicle of the coke oven, at least the coke discharge from the coke discharge side (C / S) and coke extrusion side (M / S) in the coke oven carbonization chamber length direction For the side (C / S), the particle size is segregated along the length of the furnace so that the average particle size of the coal charged is finer than the average particle size of the entire coal charged into the coal tower. A method for producing coke, characterized in that coal is deposited, loaded in a hopper of a coal charging vehicle in this state, and subsequently charged into a coke oven while maintaining particle size segregation between the hoppers, and then dry-distilled.

(2) In the above 1, at least the coke discharge side (C / S) among the coke discharge side (C / S) and the coke extrusion side (M / S) in the coke oven carbonization chamber length direction in the coal tower. The production of coke is characterized in that coal is deposited by particle size segregation along the length of the furnace by charging the coal while forming a slope that makes the coal deposition level higher than in the central area of the coke oven. Method.
In addition, in the method for producing coke of (2), in the coal tower for supplying coal to the coal charging vehicle of the coke oven, the coke discharge side (C / S) in the coke oven carbonization chamber length direction is as follows: By charging the coal while forming a slope that increases the coal deposition level from the coke extrusion side (M / S) in the furnace length direction, the coal is deposited by segregating the grain size along the furnace length direction. In this state, a method for charging coal into a coke oven is included, in which the coal is loaded into a hopper of a coal charging vehicle and subsequently charged into a coke oven while maintaining grain size segregation between the hoppers.

(3) Coke discharge side (C / S) in coke oven carbonization chamber furnace length direction when the charging method of coal into the coal tower in the above 1 is fixed point packing using a swivel belt conveyor In addition, at least for the coke discharge side (C / S) of the coke extrusion side (M / S), a slope plate is installed in the trajectory in which coal is charged, and at least for the coke discharge side (C / S) A method for producing coke, characterized by depositing coal on the wall surface side so that coal is segregated in grain size over the furnace length direction.
In addition, in the method for producing coke in (3), when the charging method of coal into the coal tower is fixed-point packing using a swivel belt conveyor, coke discharge in the coke oven coking chamber furnace length direction For the side (C / S), by installing a slope plate in the trajectory of coal being charged and charging the coal to the wall surface side, the coal is segregated in the particle size along the furnace length direction and deposited. In this state, a method of charging coal into a coke oven is included, in which the coal is loaded into a hopper of a coal charging vehicle and subsequently charged into a coke oven while maintaining the grain size segregation between the hoppers.

  In the present invention, as described above, at least for C / S, by reducing the particle size of the coal to be deposited and reducing the bulk density, the shrinkage in the width direction of the C / S coke is increased. This effectively reduces the occurrence of clogging caused by unevenness of bricks and carbonization defects in C / S.

  Further, in the present invention, in the coal tower, when the coal particle size segregation is applied as described above, by installing a granulator such as a grizzly on the upper part of the inclined region of the coal accumulation layer formed by the supply of coal. Further, particle size segregation can be further promoted.

  According to the present invention, in the coal tower, the charged coal is deposited with particle size segregation so that the particle size of C / S and M / S in the furnace length direction becomes small, and then this particle size segregation is retained. By charging the coke oven as it is, the amount of C / S and M / S coke shrinkage can be greatly increased. As a result, the unevenness of bricks and carbonization defects in C / S and M / S The resulting increase in coke extrusion current and occurrence of clogging can be effectively prevented.

Hereinafter, the present invention will be specifically described.
In the present invention, in the coal tower, at least the coke discharge side (C / S) in the coke oven carbonization chamber length direction, the average particle size of the coal charged therein is the entire coal charged in the coal tower. The mean particle size of the coal may be finer than that, and the means thereof is not particularly limited.

FIG. 1 illustrates a coal supply procedure 1 into a coal tower.
In this supply procedure 1, as shown in FIGS. 1 (a) and 1 (b), coal is charged in advance over the entire length of the coal tower to form a flat deposition surface.
Next, as shown in FIG. 1 (c), the coal is supplied only to the vicinity of the tower wall on the coke discharge side (C / S) in the coke oven carbonization chamber length direction in the coal tower. The supply of coal only to the vicinity of the tower wall may be started from the state shown in FIG.
When coal is supplied by such a method, an inclination is gradually formed on the discharge side (C / S) of the coke in the coke oven carbonization chamber length direction so that the deposition level is higher than that on the extrusion side (M / S). The coal is supplied along this inclined surface.
Here, the coal having a large particle size among the supplied coal rolls down along the inclined surface and is eliminated to the left in the figure, resulting in particle size segregation. Then, coal is supplied to the coal charging vehicle hopper in the accumulation state shown in FIG. 1 (d), and the coal accumulation level in the coal tower is lowered in this state. When the coal accumulation level in the coal tower reaches the lower limit level in the accumulation state of FIG. 1 (d) or at a predetermined accumulation level, as shown in FIG. 1 (e), the extrusion side (M / S) The coal is supplied only to the central area and the vicinity of the tower wall on the discharge side (C / S), and the coal accumulation level in the coal tower is restored and maintained.

According to the supply method as described above, a small particle size is supplied to the coke discharge side (C / S) in the coal tower.
Therefore, if the coal is charged from the coal tower into the coal charging vehicle and then into the coke oven in this accumulated state, the coke discharge side (C / S) in the coke oven carbonization chamber length direction is relatively free of particles. Coal with a small diameter will be supplied.

  As described above, the supply procedure 1 is for the coke oven coal tower in the coke oven coking chamber furnace length direction coke discharge side (C / S), by supplying the coal using the inclined surface, the coal length This is a method in which the particle size is segregated in the direction and deposited, and the charged coal having a small particle size is stacked on a C / S hopper and charged in a coke oven. As a result, the C / S particle size is reduced to lower the bulk density, the C / S coke coke widthwise shrinkage is increased, and the clogging caused by brick irregularities or poor carbonization at C / S occurs. Is prevented.

Next, FIG. 2 shows a case where a grizzly is installed as a granulator above the inclined region of the coal deposit layer.
As shown in the figure, by installing a grizzly over the sloped region of the coal deposit layer, coal sizing proceeds more effectively, and particle size segregation along the furnace length direction can be further promoted.

Next, the supply procedure 2 of coal into the coal tower will be described.
FIG. 3 shows an outline of a fixed point stacking method using a swivel belt conveyor. In the figure, number 1 is a coal tower, 2 is a belt conveyor that guides the coal to the center of the coal tower 1, 3 is a swirl that turns the coal guided into the coal tower 1 by the belt conveyor 2 and throws it into the tower 4 is a slope plate installed in the coal charging locus.

Conventionally, when there is no slope plate 4 as shown in FIG. 3, the accumulation state of coal in the coal tower 1 is as shown by a broken line in FIG.
However, when the slope plate 4 is installed according to the supply procedure 2, the coal supplied from the swivel belt conveyor 3 does not fall into the tower as it is, but is carried along the slope plate 4 to the tower wall side. Will fall from. That is, on the side where the slope plate 4 is installed, coal is supplied only to the vicinity of the tower wall. Therefore, on the slope plate installation side, an inclination is formed so that the accumulation level gradually increases, and coal is supplied along the inclined surface.
As a result, as in the case shown in FIG. 1, the coal having a large particle size of the supplied coal rolls down along the inclined surface, and the coal having a relatively small particle size remains in the vicinity of the tower wall. become. That is, particle size segregation occurs. Furthermore, when the grizzly 5 shown by the broken line is installed in FIG. 4A, this particle size segregation can be further promoted.

Therefore, if such a slope plate is installed on the coke discharge side (C / S) in the coal tower, a small particle size is supplied to the coke discharge side (C / S). Become.
Therefore, if the coal is charged from the coal tower into the coal charging vehicle and then into the coke oven in this accumulated state, the coke discharge side (C / S) in the coke oven coking chamber furnace length direction is shown in FIG. As shown in b), coal with a relatively small particle size will be supplied. In FIG. 4 (b), the ideal shape of the particle size distribution in the furnace length direction in the coke oven is indicated by a virtual line.

The particle size segregation caused by the inclination in the coal tower as shown in Fig. 4 (a) becomes the particle size distribution as shown in Fig. 4 (b) when coal is charged into the coke oven carbonization chamber. A coal charging vehicle having the same number of hoppers as the number of each cut-out opening (four in the case of FIG. 4) receives coal from the coal tower and charges coal into the carbonization chamber from each hopper. This is because a deposition slope is formed in the carbonization chamber every time and particle size segregation occurs.
This is the same for the supply procedures 3 to 5 described below.

Next, the supply procedure 3 of coal into the coal tower will be described.
In this example, grain size segregation is applied to both the coke discharge side (C / S) and the coke extrusion side (M / S) in the coke oven carbonization chamber length direction.
As shown in FIG. 5 (a), in this example, the belt conveyor 2 guides the coal to the center of the coal tower 1 and uses the side plate 6 disposed below the coal tower 1 to both C / S and M / S. Coal is supplied only to the vicinity of the tower wall. Therefore, in C / S and M / S, a slope is formed so that the deposition level gradually increases, and coal is supplied along this slope.
As a result, both C / S and M / S are supplied with a small particle size.
Therefore, if the coal is charged from the coal tower into the coal charging vehicle and then into the coke oven in this accumulated state, the coke discharge side (C / S) and coke extrusion side (M / S) is supplied with coal having a relatively small particle size, as shown in FIG. 5 (b).

Next, the supply procedure 4 of coal into the coal tower will be described.
This example is a case where grain size segregation is applied to the coke discharge side (C / S) using two types of grizzly.
As shown in FIG. 6A, in this example, the coal supplied from the swivel belt conveyor 3 is supplied to the vicinity of the C / S tower wall via the grizzly A and the grizzly B. In the figure, since Grizzly A has claws with a constant interval, coal having a size larger than this interval (for example, 6 mm) rolls along the Grizzly A and is placed outside the coal tower. Discharged. On the other hand, coal smaller than the claw interval of Grizzly A will fall near the tower wall, but under this falling flow, Grizzly B, which is a normal granulator, is arranged, The grizzly B is supplied to the vicinity of the tower wall in a state where the particle size segregation is promoted.
As a result, as shown in FIG. 6 (b), the C / S is supplied with coal having a particularly small particle size on the coke discharge side (C / S) in the coke oven carbonization chamber length direction. become.

Next, the coal supply procedure 5 into the coal tower will be described.
In this example, as shown in FIG. 7 (a), the grizzly 5 is arranged in the coal charging locus by the swivel belt conveyor 3.
In this way, when the grizzly 5 is installed, among the coal supplied from the swivel belt conveyor 3, fine particles having a small particle diameter pass through the grizzly 5 and are supplied to the C / S partitioned by the wall. However, coarse particles having a large particle diameter roll along the grizzly 5 and are supplied to the center of the coal tower.
As a result, as shown in FIG. 7B, coal having a relatively small particle size is supplied to the coke discharge side (C / S) in the coke oven carbonization chamber length direction.

As described above, at least on the coke discharge side (C / S), the coal deposited in the coal tower with particle size segregation so that the average particle size of the coal is smaller than the average particle size of the entire coal is In this state, it is loaded into a hopper of a coal charging vehicle, and subsequently charged into a coke oven while maintaining the particle size segregation between the hoppers, and then subjected to dry distillation to obtain coke.
Here, the preferred carbonization conditions in the coke oven are as follows.
-Carbonization temperature: 1050-1250 ° C
-Carbonization time: 16-24h
・ Coal moisture: 5-11%

Examples of the present invention will be described below.
Example 1
Using the apparatus shown in FIG. 8, the degree of particle size segregation of coal due to the inclined surface formed in the coal tower was investigated. The apparatus of FIG. 8 is made of transparent vinyl chloride, and the inclined surface is coated with coal. The experiment was started in such a state that coal was deposited on this inclined surface in a thickness of about 5 cm in advance, and after the coal was introduced from the top, the coal at the top was collected.
As a result, it was confirmed that the coal charged from the top of the inclined surface caused particle size segregation while rolling on the inclined surface, and the average particle size was smaller than the average particle size of the entire charged coal at the upper portion of the inclined surface. It was.

The obtained results are shown in FIG.
As shown in the figure, the average particle size of the coal at the top of the inclined surface was about 1.5 mm, which was smaller than the average value of the entire coal before charging: 2.1 mm.

Next, the bulk density when such a small particle size coal was loaded on a C / S hopper and then charged into the C / S of the coke oven carbonization chamber was calculated by simulation.
The results are shown in Table 1.

As shown in the Table, a bulk density of instrumentation Nyusumi in the coking chamber C / S of the coke oven is 742 kg / m ^3, the average bulk density of charging coal polarized析前: compared to 763 kg / m ³ 21 kg / m ³ lower.

Next, in the experiment conducted using the apparatus shown in FIG. 8, the coal was actually sampled, filled in the coke shrinkage measurement container shown in FIG. 10, and carbonized under predetermined conditions in a 40 kg carbonization furnace. The amount of shrinkage was measured. Based on the results shown in Table 1, the packing bulk density of coal was changed according to the conditions when not segregating and the conditions at the top after segregation.
The results are shown in Table 2.

  Coke shrinkage was evaluated by the clearance described below. Here, the clearance is an average amount of a predetermined area of a gap formed between the generated coke and the furnace wall (here, a stainless steel plate) (an average value of less than 400 points measured by a laser). The greater the clearance, the greater the amount of contraction.

As shown in the table, the clearance of coke produced by segregating coal particle size and reducing the bulk density to dry distillation is 14.1mm, which is larger than 13.4mm when not segregated, and the shrinkage is large. I understand that
The clearance difference in this measuring method: 0.7 mm is extremely large. From the accumulation of data so far, we have obtained a good correlation between this clearance measurement data and the actual furnace extrusion current value. Clearance: 0.3 mm, and an increase of 0.5 mm or more can predominate in coke extrusion. It has been confirmed.

(Example 2)
Using the apparatus shown in FIG. 11 having an inclined surface substantially the same as that of an actual coal tower, a charging experiment on the inclined surface was performed, and the degree of particle size segregation due to the inclined surface formed in the coal tower was investigated. Note that the inclined surface of the apparatus of FIG. 11 is coated with coal in advance.
Coal was supplied from the upper hopper 7 to the inclined slope plate 4 via the belt conveyor 3, slid on the slope plate, and then put on the inclined surface. After the coal was introduced, the coal was sampled from the slope and skirt of the deposited coal, and the particle size of the obtained coal was measured and compared. In the experiment, the blended coal normally charged in the coke oven was used as it was. The experiment was performed a total of three times using coal with initial average particle sizes of 1.9 mm, 2.2 mm, and 2.8 mm.
The results are shown in Table 3.

As shown in Table 3, regardless of the initial average particle size, the average abscissa of the coal sampled from the slope is 0.4-0.6 mm smaller than the initial average particle size, while the average of the coal sampled from the skirt region The particle size was 0.6 to 0.7 mm larger than the initial average particle size. In three experiments with different initial average particle sizes, the average particle size of the coal on the slope was reduced by 0.5 mm, and the average particle size of the coal on the foot was 0.6 mm larger than the initial average particle size.
From this experiment, it can be seen that large particle size segregation can be caused in the coal charged into the coal tower by installing the slope plate in the trajectory where the coal is charged.
Therefore, by using such a slope plate and supplying coal while forming a slope that increases the C / S coal deposition level, the particle size segregation that makes the C / S coal particle size finer. Can be given.

  In Example 2 described above, by installing a grizzly as a sizing device above the sloped region of the coal deposit layer, coal sizing proceeds more effectively, further promoting particle size segregation in the furnace length direction. Needless to say, you can.

According to the present invention, in the coal tower, the charged coal is deposited with particle size segregation so that at least the C / S particle size in the furnace length direction is small, and the coke oven is maintained while maintaining this particle size segregation. By charging, the C / S coke shrinkage can be greatly increased, and as a result, smooth extrusion can be performed without occurrence of clogging.
Moreover, the present invention can be easily adopted in an actual coke oven without causing an increase in capital investment.

It is the figure which showed the supply procedure 1 of the coal according to this invention. It is the figure which showed the supply procedure of coal at the time of installing a grizzly as a particle separator in the upper part of the inclination area | region of a coal sedimentary layer. It is the figure which showed the supply procedure 2 of the coal by the fixed point stacking system using a turning type belt conveyor. It is the figure which showed the accumulation state (a) and the particle size distribution (b) of the coke oven longitudinal direction in a coal tower at the time of supplying coal by the fixed point stacking method using a swirl type belt conveyor. It is the figure which showed the accumulation state (a) of the coal in the coal tower at the time of supplying coal by the supply procedure 3 using a Jinka board, and the particle size distribution (b) of the coke oven longitudinal direction. It is the figure which showed the accumulation state (a) of the coal in the coal tower at the time of supplying coal by the supply procedure 4 using two types of grizzly, and the particle size distribution (b) of the coke oven longitudinal direction. It is the figure which showed the accumulation state (a) of the coal in the coal tower at the time of supplying coal by the supply procedure 4 using a distribution board, and the particle size distribution (b) of the coke oven longitudinal direction. It is the schematic of the apparatus for investigating the particle size segregation degree of the coal by the inclined surface formed in a coal tower. It is the figure which showed the particle size segregation result of the coal by an inclined surface. It is the figure which showed the container for coke shrinkage | contraction amount measurement. It is the schematic of the apparatus for investigating the particle size segregation degree of the coal by the inclined surface formed in a coal tower.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coal tower 2 Belt conveyor 3 Revolving belt conveyor 4 Slope board 5 Grizzly 6 Jinkasa board 7 Hopper

Claims (3)

  In the coal tower that supplies coal to the coal charging vehicle of the coke oven, at least the coke discharge side (C / S) and the coke discharge side (C / S) in the coke oven carbonization chamber length direction (C / S) / S), the coal is charged by grain size segregation along the length of the furnace so that the average particle size of the charged coal is smaller than the average particle size of the entire coal charged into the coal tower. A method for producing coke, characterized in that it is deposited, loaded in a hopper of a coal charging vehicle in this state, and subsequently charged into a coke oven while maintaining particle size segregation between the hoppers, followed by dry distillation.   The coke discharge side (C / S) of at least one of the coke discharge side (C / S) and the coke extrusion side (M / S) in the coke oven carbonization chamber furnace length direction in the coal tower according to claim 1. A method for producing coke, characterized in that coal is deposited while being segregated in grain size over the furnace length direction by charging the coal while forming an inclination such that the coal deposition level is higher than that in the furnace central region.   The coke discharge side (C / S) and coke in the coke oven carbonization chamber furnace length direction when the coal charging method into the coal tower is fixed-point stacking using a swivel belt conveyor in claim 1 For at least the coke discharge side (C / S) of the extrusion side (M / S), a slope plate is installed in the trajectory where coal is introduced, and at least for the coke discharge side (C / S), more coal is used. A method for producing coke, characterized in that coal is deposited by particle size segregation along the furnace length direction by charging on the wall surface side.

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