JPH0480294A - Operation of chamber type coke oven - Google Patents

Abstract

PURPOSE:To produce a coke of prescribed constant strength without difficulty by regulating the formulation of raw coal so as to lessen the influences exercised on the strength of coke by the variation in the effective height of carbonization chamber between oven groups and the variation in the extent of moisture conditioning between raw coals. CONSTITUTION:In an oven group where the carbonization chamber is great in height, the coal charged into the carbonization chamber has a high bulk density and the coke produced therefrom has a high strength. In an oven group where the carbonization chamber is small in height, the coal charged into the carbonization chamber has a low bulk density and the coke produced therefrom has a low strength. A conditioned coal of low water content has a small angle of rest and a high fluidity, so that it has a high bulk density after being charged into the carbonization chamber and gives a coke of high strength. In this invention, the formulation of raw coal is so regulated as to lessen the influences exercised on coke strength by the variation in the effective height of the carbonization chamber between the oven groups and the variation in the extent of moisture conditioning between the raw coals and thereby to give cokes of constant strength.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method of operating a room furnace type coke oven for producing metallurgical coke.

<Prior Art> It is important for metallurgical coke, especially blast furnace coke, that its properties, especially its strength, are always stable from the viewpoint of stable blast furnace operation. However, when producing metallurgical coke using room-furnace coke, the effective height of the coking chamber for each coke oven group, the moisture level of the coking coal (humidified coal or wet coal), or the strength of the finished coke of the coking coal The strength of finished coke fluctuates due to variations in influencing factors, causing various problems.

<Problems to be Solved by the Invention> The purpose of the present invention is to solve the problem in a plurality of coke oven groups with different furnace heights.
M]? The object of the present invention is to propose a method for operating a room furnace type coke that can easily obtain finished coke having a predetermined constant strength when producing metallurgical coke by processing various coking coals with different W degrees.

Means for Solving the Problems> In other words, the present invention solves the problem of the difference in the effective height of the coking chamber for each coke oven group and the raw material when charging moisture-conditioning coal into a plurality of coke oven groups to produce metallurgical coke. This is a method of operating a room furnace type coke oven characterized by adjusting the blend of coking coal so as to reduce the influence of differences in the moisture content of coal on coke strength and to maintain a constant finished coke strength.

<Function> In a coke oven group where the height of the coking chamber is high, the bulk density of coking coal entering the coking chamber increases, and on the contrary, in a furnace group with a low height of the coking chamber, the bulk density decreases. As a result, the finished coke strength of the high furnace group is high, and that of the low furnace group is low.

Furthermore, the angle of repose of the pulverized coal is different between tJI wet coal and wet coal, and there is also a difference in solid fluidity. In other words, moisture-controlled charcoal with low moisture content has a small angle of repose and good fluidity. Therefore, in the case of carbon charcoal, the bulk density after charging into the coke oven carbonization chamber is improved, and a coke product with high strength can be obtained.

The present invention alleviates the above-mentioned fluctuations in the strength of finished coke by adjusting the blend of raw coal.

For example, let the heights of the coke oven blocks (A1, A2, . . . A, .) be (hl, h2, . is given as follows.

S h L = f h (a + b h r )
--------(1) However, 1-1.2,...
n a and b are positive constants. Also, let X be the difference in moisture value between wet coal and moisture-conditioned coal, and the function (S,) by which it affects the strength is shown as follows.

5X=f, (α+βx) --------
(2) However, α and β are positive constants, so the coke strength S in the case of the same raw coal blend is the sum of Sh and 38, respectively.

S = Sh, + S, --
-------- (3) From these relationships, in order to keep the coke strength constant regardless of the furnace mass or coking coal moisture, it is necessary to
It is sufficient to use a combination that compensates for the difference between h, , and s.

In other words, let the standard state values of h and x be ho and Xo, respectively, and let the differences between these and the current state of glue and x be Δh3 and Δx, and do the same for shl, S8, and S, then ΔS - ΔSh, +Δ5X = f , (a+bΔhi) +fX(α±βΔX) The raw material mixture may be used to compensate only for the intensity.

FIG. 3 is a schematic diagram showing the flow of the coking coal processing equipment.

In this figure, raw coal discharged from a coal stockyard 1 is stored in blending tanks (plurality) 2 for each brand, cut out in fixed amounts at a specified blending ratio, and charged into a crusher 3. Thereafter, the coking coal is divided into a route in which it enters the coal tank in front of the coke oven via the humidity-controlled coal equipment 6, and a wet coal route that bypasses it.

Next, for the sake of simplicity, an example in which there are 82 coke oven groups will be explained.

(1) In the case of moisture-controlled coal operation, the coking coal that has been blended in advance in blending tank 2 for furnace group A or group B is Uf4? Coal H is first stored in bunker 4.5 upstream of the coke oven group. Coking coal is tyMtW, and if there is little stock in the coal tank for B furnace group, the coking coal for B furnace group is 1Iil/W. Note that A, B
Each line shall be sufficiently tracked to prevent mixing of coking coal for each furnace group. In this case, it is effective to provide the bunker 4.5 upstream of the moisture conditioning coal installation 6 in order to prevent coal mixture at the moisture conditioning coal installation 6.

(2) In the case of wet coal operation, in blending tank 2, mix wet coal for A furnace bed or Wet coal is cut and blended and charged into bunkers 7.8 of furnace group A or group B, respectively, and stored, and separate coking coal is charged to furnace group A and furnace group B, respectively.

<Example> Fig. 1 shows the changes in coke strength in furnace groups A and B in the case where all the coke mixtures were moisture-controlled coal. The furnace height of furnace group A is 6.
．． 7m, and the furnace height of furnace group B is 5.9m, and this difference is the T1. This corresponds to about 0.5% of the difference in strength. In addition, T1. is an abbreviation for Tumbler Index, which indicates the ratio of coke with a strength of +6 remaining in a tumbler at 400 rpm, and is used as an index representing coke strength.

By the way, T1. The relationship between the strength and the strength factor of coking coal can be approximated by the following equation, for example, and since these factors can be adjusted by the blend of coking coal, it is possible to create a blend that alleviates the difference in coke strength caused by other factors. can.

TI=+f, (MBI)+f, (MF) However, MBr
is the tissue strength factor, Medium Bolatile M
Abbreviation for atter Blending Index, MF
is the fluidity strength factor MaxiIIIum Fluidi
It is an abbreviation for ty, and k is a constant.

Here, MBI and MF are T1. (
4) According to the formula, IBI, TI corresponding to the range of change in MF,
You can see the range of change in intensity. Figure 2 shows the results of changing the blending ratio between furnace groups A and B, taking into account the blending ratio of coking coal brands to correspond to the range of variation.

From this figure, the coke product strength (e.g. TI, ) is determined by A
, B reactor group can be kept within the same range.

Similarly, the difference in strength of finished coke due to the difference between moisture conditioned coal and wet coal can be utilized, and by combining them with furnace groups with different heights of carbonization chambers, it becomes possible to suppress fluctuations in coke strength.

<Effects of the Invention> According to the present invention, it has become possible to eliminate the difference in coke strength between furnace groups having different effective heights of the carbonization chamber, as well as the difference in coke strength due to the presence or absence of moisture conditioning coal treatment. In addition, not only can a large amount of low-grade coking coal be used through humidity-controlled coal processing, but also a large amount of inexpensive low-grade coking coal can be used by lowering the grade of coking coal charged into the coke oven group, which has a high effective height of the coking chamber. This can greatly contribute to reducing raw material costs.

[Brief explanation of drawings]

Figure 1 is a graph showing the change in coke strength of the A and B furnaces in the same coking coal mixture (conventional method), and Figure 2 is a graph showing the coke strength change in the A and B furnace groups in different combinations of coking coal according to the method of the present invention. The graph and FIG. 3 are schematic diagrams showing the flow of the coking coal processing equipment. ■...Coal storage yard (yard), 2...Blending tank, 3...Crusher, 4...Bunker for A furnace 5...Bunker for B furnace 6...11 Wet coal equipment , 7.7'... Bunker for A reactor group 8.8'... Bunker for B reactor group

Claims (1)

[Claims] When producing metallurgical coke by charging moisture-conditioned coal into multiple coke oven banks, it is possible to alleviate the effects of differences in the effective height of the coking chamber in each coke oven group and differences in humidity control of coking coal on coke strength. so that the finished coke strength is constant.
A method of operating an indoor coke oven characterized by adjusting the blend of coking coal.