JPH04180994A - Vertical coke oven - Google Patents

Abstract

PURPOSE:To decrease the installation cost, to improve the dry distillation efficiency and to improve the working environment by preparing a specified constitution in a coke oven wherein coke is produced by the dry distillation of powdery coal. CONSTITUTION:In a coke oven wherein coke is produced by dry distillation of powdery coal, a coal charge part 2 is provided on the upper part of a carbonization chamber 1 and a coke discharge part 3 is provided on the bottom part and the horizontal cross section of the carbonization chamber 1 is made rectangular and a protruding rid wall 10 is made on the inner face in the oven width direction.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vertical coke oven that produces coke by carbonizing coal.

(Prior technology) The coke ovens currently in common use are of the type called horizontal coke ovens, in which coal is charged from the top of the oven and coke is discharged horizontally using an extruder. It is something. This type of coke oven has a long history and a lot of operational knowledge, but due to its structure, it is necessary to have doors (referred to as oven lids) that are the full height of the coke oven on both sides to discharge coke, and carbonization There are undesirable problems such as gas leakage from the furnace lid and the generation of soot and dust when coke is discharged, resulting in environmental pollution. In addition, as ancillary equipment, coal loading cars, extruders, guide cars,
Since mobile machinery such as fire extinguishers is required, it is necessary to pay for the equipment and secure operating personnel, and the working environment is not necessarily good.

Recently, when updating coke oven equipment, attempts have been made to increase productivity and reduce pollution sources by increasing the size of coke ovens in order to alleviate the problems of horizontal coke ovens mentioned above. As mobile machinery becomes larger as a result of this trend, it does not necessarily lead to a reduction in equipment costs, and the working environment is not sufficiently improved, making it difficult to make fundamental technical improvements to horizontal coke ovens due to their structure. I have to say.

Here, the issues with horizontal coke ovens can be summarized as follows.

■ Mobile machinery is essential as ancillary equipment, which is disadvantageous in terms of equipment costs and labor savings.

■ Carbonization efficiency, that is, heating efficiency, is poor, making it impossible to reduce the installed capacity of the furnace.

■ Generation of soot and dust from the furnace opening worsens the working environment.
There is a risk of causing pollution.

■ Difficult to shut down the furnace, resulting in poor production flexibility.

Historically, in addition to horizontal coke ovens, some vertical coke ovens have also been put into practical use in Europe, and are also used in some parts of Japan. However, most of them either disappeared without being enlarged or are only operating in small quantities.

Vertical coke ovens, in which coal is charged from the top of the oven and coke is discharged from the bottom of the oven using its own weight, appear to have been operated without any problems, with almost no moving machinery used.
For example, [Recent animal charcoal production method and by-product treatment method J! ! Written by Taizo Ada, published by Maruzen Co., Ltd. (July 1912), the Elliott John type furnace, which has a rectangular horizontal cross section, and the Armstrong type furnace, which has a circular horizontal cross section, are introduced. The former uses 14 stages of horizontal flues for heating in the furnace height direction, which tends to cause temperature distribution in the horizontal direction, and gas distribution is complicated, which can easily become difficult to operate as the number of furnaces increases. It is inferred. The latter has a cylindrical furnace body and heats from the outer periphery of the furnace in the height direction using vertical flutes. However, as the number of furnaces increases, it becomes difficult to consolidate the furnaces, so the equipment area is proportional to the increase in the number of furnaces. It is predicted that the gas distribution will increase and the gas distribution will become complicated. However, since no moving machinery was required and the number of openings in the furnace was small, it is thought to be effective in suppressing soot and dust.

On the other hand, various molded coke processes have been studied, which are characterized by unmanned, continuous, and non-polluting operations, but have not yet been put to practical use.

In the molded coke method, powdered coal is agglomerated into pulverized charcoal, and this agglomerate is made into coke by direct heating with gas, but the odor emitted from the tar and pitch-based binders used during molding is environmentally hazardous. However, there are restrictions on the type of coal used in the molded coke method. Furthermore, since the heated gas used for carbonization is mixed with the gas generated during carbonization, the amount of gas inevitably increases, and the gas processing equipment needs to be increased several times the scale of the horizontal coke oven equipment. Therefore, it is unlikely that a significant reduction in equipment costs can be expected.

For the reasons mentioned above, partial improvements in the conventional technology are not sufficient to solve the problems in the currently commonly used horizontal coke ovens, and the creation of new coke production technology is strongly desired.

Therefore, the present inventors developed a "vertical coke oven and coke production equipment" and previously filed a patent application (Japanese Patent Application No. 2-99940). A coke oven in which a coal insertion port is provided at the top of the carbonization chamber, a coke discharge port is provided at the bottom, and a vertical flue and an air passage are provided on two opposing sides of the carbonization chamber with a brick wall in between, and This coke manufacturing equipment is equipped with a coal drying/preheating machine and an airflow conveying device, and is superior to conventional horizontal coke ovens in various aspects such as reducing equipment costs, improving carbonization efficiency, and improving the working environment. and coke making equipment.

(Problem to be solved by the invention) This invention, like the vertical coke oven of the above-mentioned Hikari application,
It was developed to solve the problems of conventional horizontal coke ovens, and takes advantage of the characteristics of external heating coke ovens while eliminating their drawbacks. The purpose is to provide a means to improve the

(Means for Solving the Problems) The gist of the present invention is to provide a coke oven for producing coke by carbonizing powdered coal, which has a coal charging port at the top of the carbonization chamber and a coke discharge port at the bottom. A vertical coke oven characterized in that the coking chamber is provided with a rectangular horizontal cross section and has an inner surface with a rib wall that is convex in the width direction of the oven.

Figures 1 and 2 are diagrams showing the configuration of an example of a vertical coke oven, with Figure 1 being a longitudinal sectional view and Figure 2 being A-A in Figure 1.
FIG. 3 is an enlarged horizontal cross-sectional view.

In Fig. 1, 1 is a carbonization chamber having a lip wall in the furnace width direction, 2 is a coal charging port provided at the top of the carbonization chamber 1, 3 is a coke discharge port provided at the bottom of the carbonization chamber 1, and 4 is a coke discharge port provided at the bottom of the carbonization chamber 1. 5 is an outlet for the gas generated in the carbonization chamber (carbonized gas), 5 is a vertical flue (heating flame path) provided on two opposing sides of the carbonization chamber with brick walls in between, and 6 is a vertical flue 5 for discharging the fuel gas. 7 is an air inlet for feeding air into the vertical flue 5, 8 is a combustion gas outlet for discharging the combustion exhaust gas generated in the vertical flue, and 9 is provided below the coke outlet 3. Shows the coke chute that has been removed.

In FIG. 2, 10 is a convex rib wall provided on the heating wall 13 of the carbonization chamber 1, 11 is provided parallel to the vertical flute 5, and has openings (not shown) provided at several locations in the direction of the furnace height. ) A fuel gas path 12 is configured to be able to feed fuel gas from the vertical flue 5 to the vertical flue 5, and 12 is provided parallel to the vertical flue 5 like the fuel gas path, and has openings provided at several locations in the direction of the furnace height. This air passage is configured to allow air to be fed into the vertical flue 5 from (not shown), and the fuel gas passage 11 and the air passage 12 are installed alternately in the furnace length direction with the vertical flute 5 in between. ing.

In the above, a vertical coke oven with vertical flues is shown as an example, but a vertical coke oven with horizontal flues may also be used. In that case, in order to uniformly heat the furnace in the horizontal direction, it is necessary to appropriately determine the furnace length.

A large number of furnaces configured in this manner can be provided adjacent to each other on both sides (in the vertical direction of the figure) as indicated by broken lines in FIG. 2, thereby providing a capacity commensurate with the amount of coke produced.

It is also possible to alternately install carbonization chambers and combustion chambers to form a furnace group structure like in a horizontal coke oven. In this case, furnace closing can be performed in the same manner as in a horizontal coke oven.

(Operation) In the vertical coke oven shown in FIGS. 1 and 2, coal is charged into the coking chamber 1 from the coal charging port 2 at the top of the oven. Heating takes place via a heating wall 13 from a vertical flue 5 arranged outside the carbonization chamber 1 . The material for the heating wall 13 is preferably silica brick or chamotte brick.

Fuel gas is introduced from the fuel gas inlet 6, and air is introduced from the air inlet lower, passing through the fuel gas passage 11 and the air passage 12, respectively, to the vertical flue through openings provided at several locations in the direction of the furnace height. 5, where the fuel gas and air are mixed and combusted. It is necessary to determine the size and number of the openings in advance so that the coke carbonization temperature in the furnace height direction is uniform.

The carbonized coke is discharged by its own weight by opening the furnace cover of the coke discharge port 3 provided at the bottom of the carbonization chamber 1 as shown by the broken line in FIG. Gas generated during carbonization is discharged from the generated gas outlet 4 and recovered.

In the vertical coke oven of the present invention, the raw material coal is charged from the top, and the coke after carbonization is discharged by its own weight by opening the oven lid at the bottom of the oven, so the extruder is essential for horizontal coke ovens. , does not require heavy machinery such as guide vehicles.

Heat transfer for carbonizing coal is carried out not only from the heating surface (heating wall 13 in FIG. 2) where the vertical flue 5 is provided, but also from the rib wall 10 that receives heat from the vertical flute 5. heat transfer efficiency is greatly improved.

From the viewpoint of improving heat transfer efficiency, the cross-sectional shape of the carbonization chamber 1 is determined by the distance W between the heating walls 13 where the length of the heating walls 13 corresponds to the furnace width.
The following is desirable. This is because the amount of heat transferred from the rib wall 10 increases as W/L increases. Furthermore, the longer the length d of the rib wall, the better the heat transfer efficiency;
If it is too long, the strength of the structure will decrease, so (1/
4) It is desirable to set it to about W or less.

It is desirable to preheat the air introduced from the outside using a heat exchanger that uses high-temperature combustion exhaust gas, which allows for smooth combustion and significantly reduces the amount of heat required for carbonization. Furthermore, the brick-walled heat storage chamber provided in current horizontal coke ovens is no longer necessary, and equipment costs can be significantly reduced.

The soot and dust generated from a coke oven is only generated when the lid at the bottom of the oven is opened, and it is easy to collect dust, which can be significantly reduced compared to horizontal coke ovens, improving the working environment and reducing dust pollution. It is also advantageous in terms of prevention.

Furthermore, since each furnace has an independent structure as shown in FIGS. 1 and 2, it is easy to stabilize the operation and easily respond to fluctuations in coke production.

As explained above, the vertical coke oven of the present invention can be said to be superior to conventional horizontal coke ovens in terms of reduced equipment costs, improved carbonization efficiency, and improved working environment. Additionally, compared to the vertical coke oven developed by the present inventors, which has a carbonization chamber with a rectangular horizontal cross section, the door only needs to be closed in the length direction of the oven, and the amount of bricks required to construct the carbonization chamber is small. Despite the fact that rib walls are used to partition each chamber, almost the same heat transfer promotion effect can be obtained.

(Example) The heating wall length L in the horizontal cross section is 450 mm, the distance between the heating walls W is 45 mm, and the rib wall length d is 110 mm.
A vertical test coke oven having a carbonization chamber with a rib wall thickness of 70 mm and a height of 2.5 m, as shown in Figs.
A carbonization test was conducted using carbonization gas of 00 kcal/Nm' as a fuel gas.

The properties of the charged coal are shown in Table 1, with an average charging bulk density of 715 kg/m' and an average flue temperature of 1150°C.
Adjusted to.

The thickness of the heating wall of the coke oven is 100 mm, and both the heating wall and the rib wall are made of silica brick. There were three carbonization chambers, and carbonization temperature measurements and coke sampling were carried out in the central carbonization chamber, which was less affected by heat dissipation from the end faces in the furnace length direction.

In other words, after charging coal, insert a thermocouple from the coal charging port,
0.5.1.0.1 from the bottom of the furnace to the height of the furnace in the center of the carbonization chamber
．． It was installed at a position of 5.2.0 m to measure the change in carbonization temperature (hereinafter referred to as charcoal temperature) at each position, and also to measure the strength of coke extinguished by water spraying after carbonization.

In addition, a thermocouple was attached to the outer wall surface of the furnace in line with the temperature measuring position in the center of the carbonization chamber, and the outer wall surface temperature was measured. Also, for comparison, a conventional horizontal furnace width of 450 cm is 250 kg.
Using a test coke oven, coal having the properties shown in Table 1 was carbonized, and the temperature in the coal was measured and the strength of the coke extinguished with water was measured.

The test results are shown in Table 2. In the same table, the fire-off time is the time from when the coal is charged until the temperature in the coal reaches 900°C, and the carbonization time is the time from the bottom of the furnace to 1.0°C. - This is the time until the temperature in the coal reaches 950°C and the coke is discharged.

(Hereinafter, blank space) Table 2 As is clear from the results in Table 2, the test results when using the vertical test coke oven of the present invention (example of the present invention) and the test results using the conventional horizontal test coke oven Comparing the test results (conventional example) conducted under the same conditions in terms of fire-off time, the average time in the furnace height direction for the inventive example is 17.1 hours, compared to 20.2 hours for the conventional example, which is approximately This is a 15% reduction. Furthermore, when comparing the carbonization time, it is found that the carbonization efficiency is extremely high in the vertical coke oven of the present invention, from 23.9 hours for the conventional example to 18.0 hours for the example of the present invention, which is a significant reduction of about 25%. It is recognized that the condition is good. This is considered to be due to the effect that heat is supplied not only from the heating wall but also from the rib wall of the carbonization chamber by providing a rib wall in the horizontal cross section of the carbonization chamber.

In addition, regarding coke strength, the example of the present invention is higher than the conventional example by D
+'2H shows a high value exceeding 0.6, indicating good quality. This is thought to be because even though the carbonization temperature at the center of the carbonization chamber is the same, the average coke temperature in the width direction from the rib wall to the center of the carbonization chamber is high.

Although the fire fall time tends to be longer as the height from the hearth is higher, the difference between the 0.5 m position and the 2.0-m position from the hearth bottom is within about 0.6 hours. Even with the flue combustion chamber structure, it is judged that there is no particular problem with uniform heating in the furnace height direction.

As shown in Table 2, the surface temperature of the outer wall of the furnace tends to increase slightly as it rises from the bottom of the furnace, but it is still sufficiently low, and if the heat insulating material is designed properly, the temperature from the furnace body can be reduced. It can be said that the amount of heat dissipated is small.

Furthermore, regarding the coke discharge performance, by opening the furnace lid at the bottom of the furnace, the coke is discharged by its own weight without any problem, and as long as uniform carbonization is carried out and coke shrinkage is sufficient, there is no particular problem. It was confirmed. Therefore, it is considered that coke can be easily discharged without using heavy machinery such as an extruder or a guide wheel.

Regarding the generation of soot and dust during coke discharge, although it is difficult to fully grasp the effect in a small-scale test such as this example, the amount of soot and dust generated during the horizontal 250 kg test coke oven is small. Met.

(Effects of the Invention) The vertical coke oven of the present invention is superior to the conventional horizontal coke oven in various aspects such as reducing equipment costs, improving carbonization efficiency, and improving the working environment, and will contribute to future coke manufacturing technology. It can be said that this will greatly contribute to development.

[Brief explanation of the drawing]

1 and 2 are diagrams showing the configuration of an example of the vertical coke oven of the present invention, in which FIG. 1 is a vertical sectional view, and FIG.
It is a horizontal enlarged sectional view taken along the line A-A in the figure.

Claims (1)

[Claims] This is a coke oven that produces coke by carbonizing powdered coal, and is equipped with a coal charging port at the top of the carbonization chamber and a coke discharge port at the bottom. A vertical coke oven characterized by having rib walls that are convex in the width direction of the oven.