JPH05148485A - Vertical coke oven - Google Patents

Abstract

(57) [Summary] [Structure] The carbonization chamber 1 of the vertical coke oven is formed such that the oven width 5 is constant in the oven height direction. Further, it is more effective if the piping system for supplying the fuel gas to the end flues at the lower part of the furnace is made independent from the piping systems for supplying the fuel gas to the other horizontal flues. [Effect] Uniform carbonization in the furnace height direction can be performed without adjusting the fuel gas amount, and the carbonization time can be significantly shortened to produce high-strength coke. Since the structure is simplified, furnace construction is easy and construction cost can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical coke oven capable of producing high-strength coke, which is indispensable for the blast furnace pig iron making method, and capable of reducing construction costs and operating costs.

[0002]

2. Description of the Related Art In the blast furnace ironmaking process, coke functions as a reducing agent for iron ore and also as a base material for ensuring air permeability in the furnace. In order to secure this air permeability, the coke for the blast furnace needs to be massive and have high strength. On the other hand, the required amount of blast furnace coke is just over 40 million tons / year in Japan alone, which is produced in a room furnace type coke oven.

A horizontal or vertical chamber coke oven is a brick structure in which carbonization chambers and combustion chambers are alternately arranged. Such carbonization chambers are arranged in the width direction across the combustion chambers.
Or, it is general that one furnace group is composed of about 100 gates. In most horizontal coke ovens, a coal car is installed above the coke oven, an extruder is installed on the machine side in the furnace length direction, and a guide car and a fire engine are installed on the coke side.

The size of the carbonization chamber is, for example, 0.45 m wide and long
It has a height of around 15 m and a height of around 6 m, but a taper of 50 to 70 mm diverging in the furnace length direction is provided from the machine side to the coke side. This is because in a horizontal furnace, coke after carbonization is generally discharged from the coke oven by an extruder, but if a problem occurs during this discharge, the coke will be clogged inside the furnace and discharge by mechanical force will be impossible. Since it will seriously hinder the operation of the coke oven, it has been adopted as a measure for avoiding the clogging of the coke. The taper is generally several tens of mm, for example,
In the coke oven with an average oven width of 460 mm, the machine side is tapered so that the oven width is 430 mm and the coke side is about 490 mm, so that the coke is easily pushed out toward the coke side.

On the other hand, although the size and number of horizontal furnaces are inferior to those of horizontal furnaces, vertical furnaces also exist in chamber furnace coke furnaces. FIG. 6 shows a partial vertical sectional view of an example of a conventional vertical coke oven, and FIG. 7 shows a vertical sectional view taken along the line CC of FIG. In the vertical type coke oven, coal is charged from the inlet 2 at the upper part of the furnace, but the discharge of the coke cake is different from the case of the horizontal type oven, and the furnace lid 3 is opened and the weight of the coke is used from the bottom of the furnace. Vertically. In such a vertical furnace as well, the carbonization chamber partition wall 4 is generally tapered toward the coke discharge direction as in the case of the horizontal furnace. That is, in the case of the vertical furnace, the furnace is tapered in the height direction, and the furnace width 5 becomes wider from the furnace top toward the furnace bottom.

However, considering that the coke oven is basically a brick-laying structure, an enormous amount of irregular shaped bricks must be used in order to construct such a tapered oven, and the labor for the construction of the oven is also increased. Because of this, the rise in construction costs is inevitable. In addition, it is not always considered a good idea in terms of furnace body maintenance and combustion management.

In particular, in order to discharge the coke stably, it is necessary to make the progress of dry distillation in each part of the carbonization chamber 1 the same so that the coke in the carbonization chamber 1 is sufficiently contracted.

However, in the case of the conventional furnace, since a taper of about 4 mm per 1 m is provided in the coke discharge direction, the distance from the carbonization chamber partition wall 4 to the center of the carbonization chamber in the furnace width direction is the coke discharge direction (horizontal furnace). The length of the furnace is different from that of the vertical furnace, and the height of the vertical furnace is higher. Therefore, in the case of a vertical furnace, assuming that the combustion of the multi-stage horizontal flue 6 is controlled under the same conditions and the heat is uniformly transferred to the carbonization chamber 1, the carbonization proceeds faster toward the upper side of the furnace where the furnace width 5 is narrower, The dry distillation is delayed as the width of the furnace bottom increases. Therefore, in the conventional furnace, the heat pattern is adjusted by adjusting the fuel supply amount to each horizontal flue 6 in the furnace height direction,
Combustion control is performed so that coal in the center of the carbonization chamber is carbonized simultaneously in the furnace height direction as much as possible.

For example, a typical heat pattern in the vertical direction of a vertical furnace with a taper has a shape as shown by a broken line in FIG. 5, which will be described later. The side is cold. The above heat pattern adjustment is performed by adjusting the amount of fuel gas supplied to the multi-stage horizontal flue 6, but in an industrial-scale coke oven, the number of horizontal flues 6 is enormous, and further adjustment of the amount of fuel gas, that is, In most cases, the adjustment of the flow control valve 10 depends on manual operation, and it is practically impossible to finely adjust the amount of fuel gas supplied to the multistage horizontal flue 6.

On the other hand, it is not easy to keep the temperature of the coke oven kiln opening near the oven lid 3 at a proper temperature because it is affected by heat radiation. Basically, the end flue at the lower part of the furnace supplies fuel gas that can compensate for heat radiation and performs combustion, but if a large amount of fuel gas is consumed in a part of the same fuel gas piping system 11, other flue gas will be consumed. And the combustion control thereof may be disturbed, which is not preferable. Further, a local high temperature portion is likely to be generated in this portion, which promotes damage and deterioration of the furnace material such as brick. In addition, the furnace lid may be deformed and the generated gas may leak.

[0011]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the conventional coke oven, facilitates the construction of the furnace, reduces the construction cost, and does not adjust the fuel gas amount. It is an object of the present invention to provide a vertical coke oven that enables uniform dry distillation in the oven height direction and can produce high quality coke.

[0012]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made detailed studies on the improvement of the shape of the carbonization chamber of a conventional vertical brick-type coke oven with a complicated shape. As a result, it was confirmed that coke can be discharged without problems even if the carbonization chamber partition wall is not tapered by homogenizing the carbonization in the furnace height direction to eliminate the low carbonization temperature and shrinking the coke cake sufficiently. ..

The present invention was made on the basis of the above findings, and its gist resides in the following vertical coke ovens.

A vertical coke oven in which pulverized coal is charged from the top of the furnace and coke after carbonization is discharged from the bottom of the furnace by its own weight, and the furnace width of the carbonization chamber is constant in the furnace height direction. A vertical type coke oven.

The combustion chamber is composed of a multi-stage horizontal flue which is horizontally partitioned, and the piping system for supplying the fuel gas to the end flues at the lower part of the furnace is independent of the piping system for supplying the fuel gas to the horizontal flues other than the end flues. The vertical coke oven as described above, which is characterized by being installed.

1 and 2 are views showing the construction of an example of the above-mentioned vertical coke oven. FIG. 1 is a partial vertical sectional view, and FIG.
2 is a vertical sectional view taken along the line AA of FIG.

1 and 2, 1 is a carbonization chamber, 2
Is a charging port provided in the upper part of the carbonization chamber 1 for charging powdery coal, 3 is a furnace lid provided at the bottom of the carbonization chamber 1, a furnace lid opened when the coke is discharged, 4 a carbonization chamber for partitioning adjacent carbonization chambers 1 Partition walls, 5 is the furnace width, 6 is a multi-stage horizontal flue provided inside the partition wall 4, 7 is a fuel gas inlet, 8 is preheated air in the heat storage chamber, and preheated air is provided in the carbonization chamber partition wall 4. Preheated air inlet for introducing into the horizontal flue 6 through the ascending path, 9
Is a combustion exhaust gas outlet for discharging the combustion exhaust gas generated in the horizontal flue 6 to the heat storage chamber through the combustion exhaust gas descending path provided in the carbonization chamber partition wall 4, and 10 is the amount of fuel gas supplied to the horizontal flue 6. A flow control valve 11 is a fuel gas piping system for supplying fuel gas to the multistage horizontal flue 6.
The carbonization chamber 1 has a constant furnace width in the furnace height direction.

3 and 4 are views showing an example of the construction of the vertical type coke oven, FIG. 3 is a partial vertical sectional view, and FIG. 4 is a vertical sectional view taken along the line BB of FIG. This vertical type coke oven has a piping system that can independently supply fuel gas to the end flues at the bottom of the furnace. As shown in FIG. In addition to the piping system 11A for supplying the fuel gas, a fuel gas independent piping system 11B for supplying the fuel gas is provided only to the end flue at the lower part of the furnace.

[0019]

When coke is produced by using the vertical type coke ovens shown in FIGS. 1 to 4, since the oven width 5 in the oven height direction, that is, the dry distillation width is constant, If a certain amount of fuel gas is supplied to the horizontal flue 6 in the stage, the carbonization can be advanced to the center of the carbonization chamber in the same carbonization time. Therefore, the combustion adjustment of each horizontal flue 6 becomes unnecessary.

Further, when the operating rate of the coke oven is changed, the flue temperature needs to be set higher as the oven width 5 increases if the carbonization chamber partition wall 4 has a taper, and the combustion adjustment of each horizontal flue 6 becomes complicated. However, since there is no taper in the carbonization chamber of the vertical coke oven of the present invention, the temperature of each flue may be raised or lowered at the same time. The flue temperature can be easily adjusted because it can be increased or decreased while keeping the same direction.

Furthermore, if the fuel gas piping system to the end flue at the lower part of the furnace is set to a system different from other flues (invention), combustion in the end flues can be arbitrarily controlled without affecting other flues. It becomes possible.

FIG. 5 is a heat pattern showing the relationship between the furnace height and the furnace temperature when coal is carbonized at the same carbonization time. The dotted line in the figure shows the case of a conventional vertical coke oven having a tapered carbonization chamber. The solid line is the case of the vertical coke oven having the non-tapering carbonization chamber of the invention. As shown in this figure, in the vertical coke oven of the invention of the invention, it is possible to simultaneously carry out carbonization to the center of the carbonization chamber without adjusting the fuel of each horizontal flue, and moreover, combustion in the end flue at the bottom of the furnace. The temperature drop at the kiln opening of the furnace can be reduced by controlling the temperature control separately from the other flues. Further, since it is not necessary to make the furnace temperature of the furnace bottom extremely high unlike the conventional coke oven, it is possible to prevent the brick from being damaged or deteriorated.

As described above, the vertical coke oven of the present invention is configured so that the furnace width 5 of the carbonization chamber 1 becomes constant in the furnace height direction, and the shape of the carbonization chamber 1 is smaller than that of the conventional furnace. Significantly simplified. Therefore, the deformed bricks are not required at the time of building the furnace, the work for building the furnace is facilitated, and the construction cost of the coke oven can be reduced.

[0024]

Example 1 has the configuration shown in FIGS. 1 and 2,
Using the vertical coke oven (taperless oven) of the invention in which the dimensions of the carbonization chamber are 450 mm in width, 5.0 m in furnace height and 2.5 m in furnace length, a carbonization test of blended coal having the properties shown in Table 1 is performed. (Example 1) The temperature at the center of the carbonization chamber, the dry distillation time, and the coke strength measured by a drum test were measured.

The coke oven gas was used for heating the coke oven, and the horizontal flue temperature was set to 1150 ° C. In addition,
The amount of fuel supplied to the flues other than the end flues in the lower part of the furnace was the same, but the amount of fuel supplied to the end flues was adjusted to 1.4 times the amount supplied to the other flues. Dry distillation was completed when the coke temperature at the bottom of the furnace reached 750 ° C (that is, at the dry distillation temperature of 750 ° C), at which point the furnace lid at the bottom of the furnace was opened to discharge the coke, and it was cooled by wet extinguishing. In addition, for comparison, the carbonization chamber has the configuration shown in FIGS.
The same dry distillation test was conducted using a vertical coke oven (taper oven) having a length of 20 mm, an average oven width of 450 mm, an oven height of 5.0 m, and an oven length of 2.5 m (Comparative Example 1). In Comparative Example 1, in consideration of the taper of the carbonization chamber, the fuel supply amount to the flues other than the end flues was changed by up to 10% on the furnace bottom side and the furnace top side, and the temperature increased from the furnace top to the furnace bottom. Was adjusted.

The test results are shown in Table 2. As is clear from this table, in Example 1, the dry distillation time was significantly shortened as compared with Comparative Example 1. This is considered to be because it was difficult to uniformly carry out dry distillation in the taper furnace even if the flue temperature was adjusted in the furnace height direction. Further, the coke strength in Example 1 was higher than the drum index by 0.5 or more, showing that the coke quality was uniform. That is,
According to the vertical coke oven of the present invention, there is no partial burning unevenness or delay of carbonization at each part in the furnace height direction, which is seen in the conventional furnace (taper furnace), and the carbonization time is shortened to produce high-strength coke. can do.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

[Example 2] In order to examine the dischargeability of coke in a vertical coke oven, the carbonization temperature (furnace bottom temperature) was changed using the same vertical coke oven and coal as in Example 1 and Comparative Example 1. An experiment was conducted.

The results are shown in Table 3. From this result, it is found that the furnace bottom temperature has the greatest influence on the coke discharge property, not the center temperature of the carbonization chamber or the dry distillation time. This is independent of the presence or absence of taper. That is, when the furnace bottom temperature was 750 ° C. or higher, the coke discharge property was good in both Example 2 and Comparative Example 2,
On the other hand, when the temperature does not reach 750 ° C, it is difficult to discharge coke even in Example 2. Therefore, if the furnace bottom temperature is sufficiently controlled, the coke can be discharged without any problem.

[0031]

[Table 3]

[0032]

[Embodiment 3] A vertical coke oven having the fuel gas piping system 11A and the independent piping system 11B shown in FIG. 4 was used as the fuel gas piping system 11 of the taperless vertical coke oven used in Embodiment 1. Fuel gas was supplied to the end flue at the lower part of the furnace from the independent piping system 11B, and the same tests and measurements as in Example 1 were performed except for that (Example 3). In addition, Example 3
Since the amount of fuel supplied to the end flue can be changed arbitrarily, the total amount of fuel gas supplied to the end flue was equal to that in the case of Example 1, but a large amount of fuel gas was supplied in the early stage of carbonization and in the latter stage of carbonization. Adjustments were made to reduce the amount of fuel gas.

The test results are shown in Table 2 above. As is clear from this table, in Example 3, the dry distillation time was further shortened and the coke strength was improved as compared with the case of Example 1. It was confirmed that the vertical coke oven, which has a non-tapered carbonization chamber and can independently control the combustion of the end flue, has excellent furnace operability and good coke quality.

[0034]

With the vertical coke oven of the present invention,
Uniform dry distillation in the furnace height direction can be performed without adjusting the amount of fuel gas supplied to each horizontal flue, and the dry distillation time can be significantly shortened to produce high-strength coke. Moreover, since the structure is simplified, the furnace construction is easy, and the construction cost can be reduced.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional view showing the configuration of an example of a vertical coke oven of the present invention.

FIG. 2 is a vertical sectional view taken along the line AA of FIG.

FIG. 3 is a partial vertical cross-sectional view showing the configuration of another example of the vertical coke oven of the present invention.

4 is a vertical cross-sectional view taken along the line BB of FIG.

FIG. 5 is a heat pattern showing the relationship between the height in the furnace and the furnace temperature when the carbon is carbonized by the vertical coke oven of the present invention and the conventional vertical coke oven at the same carbonization time.

FIG. 6 is a partial vertical cross-sectional view showing the configuration of an example of a conventional vertical type coke oven.

7 is a vertical cross-sectional view taken along the line CC of FIG.

Claims (2)

[Claims] 1. A vertical coke oven in which pulverized coal is charged from the top of the furnace and coke after carbonization is discharged from the bottom of the furnace by its own weight, and the furnace width of the coke chamber is constant in the furnace height direction. A vertical coke oven that is characterized by 2. A pipe system for supplying a fuel gas to an end flue at a lower part of a furnace, wherein the combustion chamber is composed of a multi-stage horizontal flue in which a combustion chamber is horizontally partitioned, and a pipe system for supplying a fuel gas to a horizontal flue other than the end flue. 2. The vertical coke oven according to claim 1, wherein the vertical coke oven is provided independently of the above.