JPH0931471A - Preliminary treatment of device for coal charged to coke oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preliminary treating device for coal charged to a coke oven capable of surely preventing the generation of dusts by connecting a drier having the function of a classification, a fine powdery coal collecting device, a slurry tank, a wet-type granulating machine, and a coal conveying conveyer, and firmly granulating the fine powdery coal. SOLUTION: This preliminary treating device for coal charged to a coke oven is constituted by crushing the coal cut out from a blending vessel 1 by a crusher 2, then introducing the crushed coal to a drier having the function of classification 4 through a hopper 3, drying it by blowing a hot-air from a hot-air generating furnace 5 and also separating it at the objective separating point of coarse grain coal and fine powdery coal by adjusting the strength of the flow rate of the blowing hot air. The coarse grain coal is filled into a coarse grain coal hopper 6, while the fine powdery coal is collected by a fine powdery coal collecting device 7, introduced into a slurry tank 8 to make an aqueous slurry by adding a heavy quality oil and water, and then into a wet-granulating device 9 for the wet-granulation, and the obtained granulated coal is drained by a sieve-bed 10, dehydrated by a dehydrating machine 11, filled into a hopper for the granulated coal 12, cut out onto a coal conveying conveyer 14 together with the coal from the coarse grain coal hopper and conveyed to the coke oven.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a pretreatment facility for coal charged in a coke oven.

[0002]

2. Description of the Related Art As a manufacturing method for improving the quality of coke for iron making, it is known to dry coal to improve the coal packing density in a coke oven. At this time, it is also known that fine powder is separated due to decrease in water content of coal and causes dust during transportation of coal, which adversely affects the environment.
Therefore, the dry coal is separated into coarse coal and fine coal, and the coarse coal is fed into the coke oven as it is and is carbonized to obtain coke. On the other hand, pulverized coal becomes a dust source at the transfer section of the transfer conveyor when it is transferred to the coke oven, and also mixes in the gas generated by the coke oven when it is charged into the coke oven, and enters the tar, ammonium sulfate, etc. to be recovered. Therefore, it is also known to carry it into a coke oven by carrying out a treatment such as granulation to increase the diameter so that it does not become a dust source and the like.

However, as a pretreatment method for coal which can improve the strength of the granulated coal as described above and prevent it from collapsing during transportation, heavy oil is added to the coal,
Dry granulation is disclosed in JP-B-49-28241.

[0004]

In the method of dry granulation of coal as described above, the strength of coke does not improve so much, and after granulation, when transferring to the coke oven by connecting the conveyor, it collapses at the connecting portion. A large amount of pulverized coal is generated and dust is generated, deteriorating the environment. Furthermore, when charging the coke oven, the fine coal is mixed into the coke oven gas, and the tar and ammonium sulfate recovered from the coke oven gas are mixed with the fine coal. There is a problem that quality will be deteriorated. In particular, in recent years when it is necessary to consider the environment, the dust collection tends to be strengthened, which is a big problem. The present invention has been made to advantageously solve such a problem, and to provide a coke oven charging coal pretreatment facility that can reliably and stably improve the strength of coke. It is intended.

[0005]

The features of the present invention include a dryer with a classification function, a pulverized coal collecting device, a slurry tank, a wet granulator, a dehydrator, and a coal transport conveyor. Pretreatment equipment for coal charged in coke ovens, which is characterized by being installed in series. And a dryer with a classifying function, a fine coal collector, a kneader, a slurry tank, a wet granulator, a dehydrator, and a coal conveying conveyor, which are characterized in that they are connected in a coke oven. This is a pre-treatment facility.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In a dryer with a classification function,
For example, when the crushed coal is dried, that is, when it is charged into the coke oven, the coal moisture content is increased to about 5 to increase the bulk density.
%, The bulk density does not improve proportionally even if it is dried to less than 2%, so the lower limit is preferably 2%.
In this way, the dried coal is simultaneously separated into coarse coal and fine coal, and as the particle size of the fine coal to be separated, the height of the conveyor connecting portion, the height of the coke oven, the coke oven capacity, etc. Depending on the amount of gas generated,
The particle size (weight) of the pulverized coal mixed in the dust source or the gas generated by the coke oven changes, so it is decided according to these conditions. The capacity of the coke oven currently in operation, the conveyor If the height of the connecting section is 0.
It will be any value within the range of 1 to 0.4 mm (average particle size).

Thus, the coarse coal separated into the coarse coal and the fine coal is filled in the coarse coal hopper, and the fine coal is guided to and collected by, for example, a bag filter as a fine coal collecting device.

As described above, the separated and collected fine coal powder is introduced into a slurry tank, and as heavy oil, for example, tar,
Waste oil of steel rolling oil, or a mixed oil thereof is added. In particular, tar is separated from coal when carbonized, and is advantageous in strength during granulation because it has affinity with coal. However, 5 to 40% is sufficient as the amount of the heavy oil added, and if it is less than 5%, the function as a binder for reliably granulating the pulverized coal becomes insufficient, and it easily collapses. If so, the granulated coal becomes soft, which is not preferable. Along with the addition of such heavy oil, 10 to 40% of water is added to obtain a water slurry.

Next, the so-called wet granulation is carried out by introducing the powder into a wet granulator and using the added water as a medium to pulverize fine coal and heavy oil in water while exerting a centrifugal force to compress and granulate. . Since such wet granulation does not include gas in the granulated coal unlike the dry granulation, the granulated coal becomes extremely dense granulated coal and the strength can be surely improved.

Before adding the heavy oil and water to the pulverized coal to form a water slurry, the pulverized coal is introduced to, for example, a kneader in advance, the heavy oil is added and kneaded, and then the slurry tank as described above. It is possible to prevent water entrapment in the pulverized coal during granulation by introducing water into a water slurry by adding water and performing wet granulation, thereby further improving the strength of the granulated coal. The granulated coal particle size for granulating the pulverized coal in this manner is a particle size exceeding the separation point of the pulverized coal separated into the coarse coal and the fine coal as described above.
That is, if the granulated coal particle size is less than the separation point of the pulverized coal,
As described above, it is not preferable because it becomes a dust source at the transfer section of the conveyor.

After the granulated coal is prepared as described above, it is dehydrated by a sieve bend, a hot air spray, a dehydrator or the like. It is preferable that this dehydration treatment is stopped by dehydration of the water content of the dry coal (coarse coal) or more. That is, some fine coal is also mixed in the coarse coal separated after drying as described above, when the coarse coal and granulated coal are mixed and conveyed to the coke oven, Moisture (water) wets the fine coal in the coarse coal to prevent dust generation, and also prevents the fine coal from mixing in the gas generated in the coke oven when it is charged into the coke oven. . In addition, by leaving water in the granulated coal, the amount of dehydration is reduced so much that there is no need for drainage, and therefore wastewater treatment equipment is also unnecessary, which is extremely advantageous. For example, if the water content of normal coke oven charged coal is dried to about 2% and the separated coal particle size is 0.3 mm, coarse coal is about 70% and granulated coal is about 30%. 5 in coarse coal
% Of fine powder contained in less than 0.3 mm adheres to the granulated coal after being mixed with the granulated coal and before charging into the coke oven, so that dust generation can be reliably prevented.

As described above, the granulated granulated coal is filled in the granulated coal hopper, and the coarse coal is filled in the coarse coal hopper as described above and conveyed to the coke oven on the cutting conveyor. It is mixed by shaking the conveyor, etc., and is loaded into the coke oven.
Coke is produced by dry distillation. in this way,
It is also possible to transfer the coarse coal and granulated coal directly to the coal transport conveyor without once filling the hopper.

[0013]

EXAMPLES Next, examples of the equipment of the present invention will be described. Example 1 In FIG. 1, the coal cut out from the mixing tank 1 is crushed by a crusher 2
And then to the dryer 4 with a classification function through the receiving hopper 3 to blow hot air from the hot air generating furnace 5 to dry it, and at the same time adjust the strength of the hot air blowing air volume to obtain the target coarse coal and fine coal. Separation (classification) at the separation point of
The coarse coal is filled in the coarse coal hopper 6. On the other hand, the pulverized coal is collected by the pulverized coal collecting device 7 and is collected in the slurry tank 8
Into the wet granulation machine 9, the heavy oil and water are added at the same time to make a water slurry, and then the water slurry is charged into the wet granulator 9 and wet granulated to obtain granulated coal. After that, the water is drained by the sieve bend 10, and then dehydrated by the dehydrator 11, and the granulated coal hopper 12 is filled. Sieve bend 10 and dehydrator 11
The water dehydrated in (1) is supplied to the slurry tank 8 through the pipe 13 and is circulated for water slurry production.

Accordingly, the coarse coal and the granulated coal are cut out from the coarse coal hopper 6 and the granulated coal hopper 12 to the coal conveying conveyor 14 arranged in the coke oven (not shown), and rocked during the transportation. As a result, the coal is brought into a mixed state on the coal transport conveyor 14 and is loaded into the coke oven.

Example 2 In FIG. 2, the coal cut out from the blending tank 1 is crushed by a crusher 2
And then to the dryer 4 with a classification function through the receiving hopper 3 to blow hot air from the hot air generating furnace 5 to dry it, and at the same time adjust the strength of the hot air blowing air volume to obtain the target coarse coal and fine coal. Separation (classification) at the separation point of
The coarse coal is filled in the coarse coal hopper 6. On the other hand, the pulverized coal is collected by the pulverized coal collecting device 7 and guided to the kneading machine 15, where heavy oil is added to the dried pulverized coal and kneaded, and then introduced into the slurry tank 8 to form a water slurry. After that, the water slurry is charged into the wet granulator 9 and wet granulated to obtain granulated coal. After that, the water is drained by the sieve bend 10, then dehydrated by the dehydrator 11, and filled in the granulated coal hopper 12. The water dehydrated by the sieve bend 10 and the dehydrator 11 is passed through the pipe 13 to the slurry tank 8
It is supplied to and recycled for producing water slurry.

Thus, the coarse coal and the granulated coal are cut out from the coarse coal hopper 6 and the granulated coal hopper 12 to the coal conveying conveyor 14 arranged in the coke oven (not shown), and rocked during the transportation. As a result, the coal is brought into a mixed state on the coal transport conveyor 14 and is loaded into the coke oven.

[0017]

According to the method of the present invention, it is possible to stably improve the strength of granulated coal made of fine coal, prevent dust generation during transportation to a coke oven, etc., and prevent environmental deterioration. It is possible to avoid mixing of fine coal into the gas generated in the coke oven during charging into the coke oven.
Almost no contamination with ammonium sulfate and the like can be avoided, and deterioration of quality can be avoided. Therefore, the quality of coke can be improved by drying the coal without major modification of the existing coke oven and incidental equipment, and great effects such as stabilization of blast furnace operation can be achieved.

[Brief description of drawings]

FIG. 1 is a flowchart showing an embodiment of the present invention.

FIG. 2 is a flowchart showing an embodiment of the present invention.

[Explanation of symbols]

 4 Dryer with classification function 7 Fine coal collector 8 Slurry tank 9 Wet granulator 11 Dehydrator 14 Coal conveyor 15 Kneader

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Serizawa 5-3 Tokai-cho, Tokai-shi, Aichi Nippon Steel Co., Ltd. Nagoya Steel Works (72) Inventor Masa Sato 5-3 Tokai-cho, Tokai-shi, Aichi Nippon Steel Co., Ltd. Nagoya Steel Works

Claims (2)

[Claims] 1. A coke oven-loaded coal characterized in that a dryer with a classification function, a pulverized coal collecting device, a slurry tank, a wet granulator, a dehydrator, and a coal conveying conveyor are connected in series. Pre-treatment equipment. 2. A coke characterized in that a dryer having a classification function, a fine coal collector, a kneader, a slurry tank, a wet granulator, a dehydrator, and a coal conveyor are connected in series. Pretreatment equipment for coal charged into the furnace.