JPH07109468A - Method for thermally baking semicoke - Google Patents

Abstract

PURPOSE:To improve the efficiency of heat exchange by pushing a semicoke contg. a specified amt. of remaining volatiles derived from a coal charge out of a coke oven chamber at an early stage and burning the volatiles in a prechamber or in a baking oven. CONSTITUTION:Coke is produced by pushing a semicoke out of a coke oven chamber of a chamber oven at a coke temp. at the center of the chamber of 600--900 deg.C and introducing air into the prechamber and/or the baking oven of CDQ(coke dry-quenching equipment to burn mainly a combustible gas remaining in the semicoke to thereby bake it. The semicoke, when pushed out of the chamber as above, contains 1-5wt.% remaining volatiles derived from the coal charge. The air is introduced in an amt. of 20-180Nm<3>/ton-coke into either the prechamber or the baking oven or into both of them in an arbitrary ratio to burn mainly a gas generated from coke to thereby rapidly heat the semicoke to 1,000 deg.C or higher.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a room-type coke oven, in which the coke temperature in the carbonization chamber is 600 to 900 ° C. The present invention relates to a method for producing coke for a blast furnace, which is rapidly heated and fired in a chamber or in a firing furnace. Here, the semi-coke is 6 in the carbonization chamber of the chamber type coke oven.
It is a coke in the middle of carbonization that has undergone carbonization at 00 to 900 ° C and has residual volatile components (volatile matter MVM) derived from charging coal. The temperature of this semi-coke is the average temperature of the core temperature in the charcoal measured at the height of the coking chamber directly below the charging hole, and the residual volatile content is the average of the semi-coke produced in one kiln. is there.

[0002]

2. Description of the Related Art In a room type coke oven, the coke temperature is 70
As a coke manufacturing method, the semi-coke produced at a low temperature of 0 to 900 ° C. is fired in a pre-chamber of a coke dry digestion facility (hereinafter referred to as CDQ) to improve the quality to obtain a finished blast furnace coke. JP-A-2-194087
There is a "method for producing blast furnace coke" in Japanese Patent Publication No.
It only describes that the coke is rapidly heated and burned by burning the coke generating gas in the prechamber of Q.

Further, Japanese Patent Laid-Open No. 2-199191 discloses that
In a dry digestion facility for blast furnace coke, feed-forward control of the amount of air introduced into the pre-chamber of the facility according to the properties of the coke thrown into this facility, and in addition to this, a semi-chamber inside the pre-chamber is controlled. It is disclosed that the fine coke and the coke temperature or the combustible gas component concentration are finely adjusted and feedback-controlled to a preset value.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to provide a coke oven with a coke temperature of 6 at the center of the coke chamber.
In a method for producing coke, which comprises performing early kilning at a low temperature within a range of 00 to 900 ° C., heating and firing the semi-coke in a CDQ pre-chamber or a firing furnace, and improving quality.
It is to provide firing conditions for optimal quality improvement.

However, the conventional techniques have not shown the conditions of introduced air and the properties of the semi-coke for achieving the optimum firing, and there have been the following problems in improving the quality by firing.

1) The amount of introduced air is such that semi-coke can be calcined at a temperature of 1000 ° C. or higher for sufficiently improving the quality.

2) The amount of introduced air is appropriate in order to prevent quality deterioration due to burning of the semi-coke itself.

3) Appropriate residual volatile components of semi-coke (V.
M. ).

4) Residual volatiles (V.
M. ) The amount of residual volatile matter that does not adversely affect quality improvement due to shrinkage due to generation and thermal stress in semi-coke lump.

5) It is possible to introduce air satisfying the above 1) to 2) by the properties of the injected semi-coke.

6) The above problems have been observed at any position in the CDQ prechamber or the firing furnace, and the quality can be improved uniformly.

[0012]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that the volatile content of semi-coke at the time of firing remains in the range of 1 to 5%. And CD
The amount of air introduced into the Q pre-chamber or firing furnace is 2
The ratio of 0 to 180 Nm ³ / t-coke makes it possible to improve the quality at an average feeding interval of semi-coke to CDQ.
The inventors have found that it is possible to raise the temperature to 000 ° C. or higher, and completed the present invention.

That is, according to the present invention, the coke temperature in the center of the carbonization chamber of the chamber type coke oven is kiln-fired at a low temperature of 600 to 900 ° C., and the semi-coke is introduced into the prechamber of the CDQ or the firing oven. However, in the method of producing coke, which is mainly produced by burning residual combustible gas and burning it, the volatile matter derived from the charging coal remaining in the semi-finished coke is early kiln in the range of 1 to 5%, The C
20 to 180 Nm ³ / t-in DQ pre-chamber or firing furnace
The coke air is introduced into the prechamber or the calcining furnace by allocating the total amount or an arbitrary ratio to the prechamber and the calcining furnace, and the gas mainly generated from the semi-coke is burned in the coke air, and the semi-coke charging interval is set. Within 10
It is a method for heating and firing semi-finished coke in which product coke is produced by rapid heating to 00 ° C or higher.

The present invention will be described in detail below. The baking equipment used in the present invention includes a CDQ pre-chamber and a baking furnace, which are the remaining equipment, and the baking furnace is a fixed type or movable type installed between the coke oven and the CDQ, or installed on the top of the CDQ. It is conceivable that it is connected to the CDQ, and there are a rotary kiln and a moving bed type as the type, but other types may be used.

Further, the firing itself may be completed only in the firing furnace, or may be preheated in the firing furnace and further fired in the CDQ prechamber. As a method of introducing air, there is a method of naturally aspirating by negative pressure or a forced introduction by a blower by adjusting the pressure in the system. In addition, as the introduction equipment, it is possible to introduce from the outer peripheral part from a fixed duct, but in order to make the firing state uniform, a movable air introduction lance is installed in the prechamber space and it can be introduced at any position. It is desirable to do.

Here, a system other than the lance may be used as a facility for introducing air into an arbitrary position. Also, if the temperature distribution on the surface of the semi-coke layer is measured and used by a radiation thermometer or other method as a state variable for controlling the introduction position, the temperature rising state can be made uniform and the variation in quality improvement can be reduced. You can A combustible gas concentration distribution derived from semi-coke may be used instead of the temperature distribution.

The amount of volatile matter remaining in the semi-coke to be fired is preferably 1 to 5%, and when it is 1% or less, the amount of combustible gas as a fuel required for raising the temperature is small, The coke itself is burned, and quality improvement cannot be expected. Further, when 5% or more of the volatile matter remains, rapid heating at the time of firing rapidly generates the volatile matter, and the shrinkage causes thermal stress in the semi-coke lump to cause internal microcracks that deteriorate the quality. For the above reasons, the residual volatile content of the semi-coke is limited to 1 to 5%.

Furthermore, the amount of air introduced into the CDQ pre-chamber or the sintering furnace during sintering, 20 to 180 ³ / t-coke is desirable, for quality improvement in 20 Nm ³ / t-coke less air introduction amount Insufficient heating, and above 180 Nm ³ / t-coke, the amount exceeds the volatile content remaining in the target semi-finished coke, causing the coke itself to burn and reducing the quality improvement effect. For the above reasons, the amount of introduced air is 20
~ 180 Nm ³ / t-limit coke. Stable operation and reliable quality improvement can be realized by introducing the above air amount at the semi-coke feeding interval.

[0019]

In the present invention, since a CDQ pre-chamber or a firing furnace is used as an apparatus for heating and firing the semi-coke, the sensible heat of the introduced semi-coke at 600 to 900 ° C. is retained, The residual combustible gas that is generated can be combusted by introducing air, and the heat of combustion can heat and sinter the semi-finished coke. By raising the maximum temperature of the coke to 1000 ° C. or higher by this temperature rise, the dry distillation of the semi-coke is completed, and the quality of the product coke can be improved sufficiently.
Here, the residual volatile matter of the semi-finished coke is set to 1 to 5% and the amount of introduced air is set to 20 to 180 Nm ³ / t-coke to achieve the above-mentioned problems and stably produce high-quality coke. be able to.

[0020]

EXAMPLES The present invention will be described in more detail below with reference to the drawings and flow sheets, but the present invention is not limited to these examples. The comparative test illustrates the superiority of the present invention. This test was conducted using the room-type coke oven 1 which is a production facility, and the facility specifications are as follows. Facility specifications Chamber type coke oven Carbonization chamber (mm): Furnace height 5500 mm × Furnace width 450 mm × Furnace length 15
The operating conditions of the 700 mm chamber type coke oven 1 are shown in Table 1 below.
In addition, as a comparative example, one charged under the same conditions was tried under the condition that the operating conditions of the present invention were not satisfied. The following operating conditions are average values of 45 kilns.

[0021]

[Table 1]

As a result, under the conditions of the present invention, the kiln removal of semi-finished coke could be stably carried out on an industrial scale. On the other hand, in the comparative example, the variation in the firing temperature of the semi-coke is increased, and the variation in the coke temperature in the carbonization chamber is increased.Therefore, a kiln in which the extrusion current value from the carbonization chamber exceeds the control upper limit appears, Implementation on an industrial scale was not possible. The results are shown in Table 2.

[0023]

[Table 2]

Residual volatiles of the semi-coke discharged from the kiln (V.
M. ) Is as shown in Table 3 below, and according to the above operating conditions,
The residual volatile content per semi-coke can be 1 to 5%.

[0025]

[Table 3]

FIG. 4 shows the feedforward control of the present invention,
It is a flow sheet which shows the flow of feedback control.

FIG. 4 is a flow sheet showing an air amount introduction control method for uniformly firing the semi-coke. 11 is the furnace wall temperature measured by a detector attached to the extruder of the room-type coke oven, the furnace temperature measured in the upper part of the combustion chamber, the so-called tar exhaustion when the temperature of the center of the carbonization chamber is 600 ° C. or higher The data of the placing time defined by the time until the time of extrusion which is actually fired at a low temperature is shown. No. 12 is a coke temperature of 600 as the property of the semi-coke to be fired.
It shows that the semi-coke has a volatile content of 1 to 5% remaining at a temperature of ~ 900 ° C. 13 indicates that the amount of air for firing when raising the coke temperature to 1000 ° C. at an interval between them requires 20 to 180 Nm ³ / t-coke, which is set in the firing furnace (CDC prechamber). It is shown that the total feed air amount 4 is determined by the feed-forward control.

On the other hand, in a calcining device such as a CDQ pre-chamber, semi-coke and coke temperature and combustible gas concentration of each part are measured (16) and the air is adjusted so as to have a predetermined temperature rising pattern and a concentration decreasing pattern. The introduction position and the introduction amount at that position are determined (17). Based on this 17, the total air introduction amount 14 is specified by the feedback control into the air introduction position and the introduction amount at that position, and the firing device 15 is instructed.

Table 4 below shows the operating conditions of CDQ when firing semi-coke by the above control method and the quality of product coke at that time. Here, as a comparative example, a case was shown in which the semi-coke produced by the above-mentioned properties, which was kiln-fired at 700 ° C., was fired under a condition outside the scope of the present invention. In the table, P / C means a prechamber.

[0030]

[Table 4]

As is clear from Table 4, in the present invention, since the firing was carried out uniformly according to the properties of the semi-coke, a high quality product coke with less variation was obtained. When the firing conditions of the invention were exceeded, the quality of the product coke deteriorated in each case, and the amount of steam recovered in the exhaust heat boiler also decreased.

[0032]

According to the present invention, the coke temperature in the center of the carbonization chamber of the chamber type coke oven is kiln-fired at a low temperature of 600 to 900 ° C., and the semi-coke is air-cooled in a CDQ prechamber or a firing furnace. When the quality is improved by introducing and firing it, the optimum quality can be improved according to the properties of the input semi-coke. Further, by uniformly distributing the introduced air by the above-mentioned method, it is possible to carry out uniform firing and quality improvement, and it is possible to reduce the quality variation of the product coke. The uniform air introduction and the appropriate air introduction amount suppress the combustion of the coke itself, preferentially burn the combustible gas, and prevent the deterioration of the quality. By increasing the coke sensible heat by firing, it is possible to increase the steam generation in the exhaust heat boiler and also to improve the heat exchange efficiency by reducing the temperature distribution at the same height in the cooling chamber due to the uniform temperature rise. It is possible to increase steam production.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing the relationship between a coal car, an extruder, and a semi-coke receiving car in a room-type coke oven.

FIG. 2 is a schematic plan view for explaining names of respective parts of the coke dry fire extinguisher.

FIG. 3 is a flow sheet showing the flow of the air introduction amount control method of the present invention.

[Explanation of symbols]

 1-room type coke oven 2 extruder 3 coal-charging vehicle 4 semi-coke receiving vehicle 5 semi-coke charging equipment 6 CDQ 7 steam recovery equipment 8 coke unloading equipment 9 closed circulation path 10 pre-chamber 11 feed-forward measurement factor 12 set Properties of semi-coke 13 Range of introduced air amount for feed forward control 14 Air introduction amount (controlled amount) 15 Firing device such as CDQ pre-chamber 16 Measurement factor in CDQ pre-chamber 17 Feedback control amount in CDQ pre-chamber

Claims (1)

[Claims] 1. A kiln is discharged at a low coke temperature of 600 to 900 ° C. at the center of a carbonization chamber of a room-type coke oven, and the semi-coke is blown with air in a prechamber of a coke dry fire extinguisher or a firing furnace. In the production of coke, which is introduced and mainly burns the remaining combustible gas, and calcinates it into a product, in the production of coke, the volatile content derived from the charging coal remaining in the semi-coke is in the range of 1 to 5%. Early kiln removal, 2 in the pre-chamber or firing furnace of the dry fire extinguishing equipment
The amount of 0-180 Nm ³ / t-coke air is introduced into the prechamber or the calcining furnace in the total amount or at an arbitrary ratio by being allocated to the prechamber and the calcining furnace, and the gas mainly generated from the coke is burned therein. A method for heating and baking semi-coke, in which product coke is produced by rapidly heating to 1000 ° C. or higher within a semi-coke charging interval.