JPH044380B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for sintering when charging a sintering raw material onto a pallet of a sintering machine using a sieve in which a plurality of strips are arranged in parallel. This invention relates to a method of charging sintering raw materials with a distribution that homogenizes the reaction.

[Conventional technology]

In the method of manufacturing sintered ore from ironmaking raw materials such as fine ore, iron ore powder of approximately 10 mm or less is mixed with coke of appropriate fineness and limestone powder as necessary, and this mixture is supplied to a sintering pallet. are doing.
Then, the coke on the surface of the supplied sintering raw material is ignited, the coke is combusted while sucking air downward, and the combustion heat generated at this time sinteres the fine ore.

Here, when the sintering raw material is distributed with a uniform particle size distribution along the height direction of the raw material layer, due to heat movement inside the raw material layer, the lower part of the raw material layer becomes higher in temperature and the ventilation resistance increases. do. In addition, the surface layer portion is cooled by the drawn outside air, resulting in insufficient temperature rise and incomplete sintering. As a result, the strength of the sintered ore decreases and the sintered ore is pulverized during post-processing such as crushing and sieving, so that the proportion of the sintered ore that is not used as a raw material for blast furnace charging increases.

Therefore, in order to charge the sintering raw material into the pallet of the sintering machine while distributing the sintering raw material with a continuous particle size distribution under stable conditions, the present inventors set up multiple pallets along the flow direction of the sintering raw material. We developed a charging method using a sieve with strips arranged in it, and filed applications as Japanese Patent Application No. 62-21401 and Japanese Patent Application No. 62-85543.

[Problem that the invention seeks to solve]

When using a sieve in which these strips are arranged, it is possible to give a predetermined particle size segregation, dispersion, etc. to the sintering raw material layer formed on the pallet of the sintering machine. Therefore, compared to conventional charging methods, the sintering reaction is made more uniform, making it possible to produce sintered ore at a higher yield.

However, even when charging the same sintering raw material pallet, the air permeability on the pallet wall side is higher than that at the center of the pallet. This is because the degree of classification, degree of dispersion, etc. of the charged sintering raw material becomes smaller on the pallet wall side. As a result, it is inevitable that the sintering reaction will still be accelerated in some areas and insufficient sintering will occur in other areas. Therefore, it is necessary to operate the charging equipment in a way that reduces the degree of classification or degree of dispersion, but at present there is no guideline as to how much the degree of classification or degree of dispersion should be reduced. .

Therefore, the present invention aims to charge the sintering raw material while correcting the influence of the properties of the sintering raw material, thereby creating a raw material layer in the pallet of the sintering machine that allows for a more uniform sintering reaction. The purpose is to form on top.

[Means for solving problems]

In order to achieve the purpose, the sintering raw material charging method of the present invention detects the properties of the sintering raw material charged on the pallet of the sintering machine, such as the packing density, air permeability, and fluctuations in red temperature. The present invention is characterized in that, based on the detected value, the position and/or attitude of a sieve made of a plurality of strips extending along the flow direction of the charged raw material is automatically controlled.

〔Example〕

Hereinafter, the features of the present invention will be specifically explained using examples with reference to the drawings.

FIG. 1 shows an outline of the apparatus used in this example.

The sintering raw material 1 that has fallen from a container such as a hopper is
While rolling on the chute 2, the sulfur is released downward. Below this chute 2, a plurality of strips are placed as sintering raw material 1.
A sieve 3 arranged along the flow direction is provided, and the sintering raw material 1 is classified by this sieve 3 and supplied to the pallet 4 of the sintering machine, and the raw material layer 5
form. The bulk density distribution of the raw material layer 5 on the pallet 4 in the axial direction tends to be smaller on the wall side of the pallet 4, and therefore the air permeability is also increased.

FIG. 2a shows an example of this bulk density distribution viewed along the width direction of the raw material layer 5. When the high density of the raw material layer 5 is reduced at both ends in this manner, the air permeability at both ends becomes large. As a result, the sintering reaction tends to proceed excessively at both ends, and tends to be insufficient at the center. Therefore, in such a case, the classification ability or dispersion ability at both ends of the sieve 3 is reduced to improve the bulk density at both ends of the raw material layer 5.

As a means for this purpose, a densitometer 6 is inserted into the raw material layer 5, and the bulk density of the raw material layer 5 obtained by the densitometer 6 is sent to the calculator 7 as an electric signal. The computing unit 7 compares this input signal with a reference value to control the position and/or attitude of the sieve 3 corresponding to the actually measured bulk density. The density meter 6 used at this time is γ
There are linear densitometers, etc.

Further, the sintering speed varies depending on the permeability in the width direction of the charged raw material layer 5. Therefore, the air permeability in the width direction can also be detected by measuring the conditions in the red tropics, that is, the sintering rate.

That is, after the coke in the surface layer is ignited in the ignition furnace 8, the combustion reaction moves downward in response to the airflow sucked downward. As a result, in the raw material layer 5 that has passed through the ignition furnace 8, as sintering progresses, a sintering progressing portion 9 is formed that becomes lower toward the ore discharge side. Sintering progressing part 9 on this ore discharge side (at the end of sintering)
This is the so-called red tropics, which has high brightness. Therefore,
An industrial camera 10 is placed to face this sintering progressing section 9 .

FIG. 2b shows an example of the red tropics observed with the industrial camera 10 in the width direction. In this example,
The sintering reaction progresses slowly at both ends due to low air permeability. Therefore, the sintering reaction has been completed in the center in the width direction, but the red zone is at a high position at both ends. This sintering material below the red zone has not yet undergone a sintering reaction. When this is discharged from the sintering machine as it is, the sintering yield is reduced. On the other hand, if it is attempted to completely sinter this portion, the sintering time will become longer and productivity will decrease.

Therefore, the shape of the red tropics and its changes are observed using an industrial camera 10, and the data is input to the calculator 7 as an electrical signal. Then, the computing unit 7 compares this input signal with a reference value, increases the classification ability or dispersion ability at both ends of the sieve 3, and increases the classification ability or dispersion ability at both ends of the raw material layer 5 in accordance with the observed red tropical shape. reduce the density of the parts. By this,
The air permeability at both ends of the raw material layer 5 is improved, sintering at both ends becomes appropriate, and the red zone can be lowered uniformly in the axial direction of the raw material layer 5.

In the example shown in FIG.
This shows the state where input is being made. However, the present invention is not limited to this, and the state of the raw material layer 5 can also be detected by the density meter 6 and/or the industrial camera 10. In addition to this, means for detecting the filling state of the raw material layer 5 include measuring the passing wind speed in the longitudinal direction at a plurality of positions on the surface of the sintered layer in the width direction of the pallet to detect air permeability.

Based on the data obtained by these detectors, the calculating unit 7 calculates the classification ability or dispersion ability of the sieve 3, and inputs the calculation result to the operating section 11 of the sieve 3 as a control signal. Based on this control signal, the inclination angle of each strip with respect to the horizontal plane constituting the sieve 3, the opening angle between adjacent strips, the gap between the strips, the distance between the sieve 3 and the raw material layer 5, the sieve adjustment for the chute 2, etc. 3. Adjust one or more of the positional relationships, etc.

FIG. 3 shows an example of an apparatus for adjusting the inclination angle of each strip of the sieve 3 with respect to a horizontal plane.

The operating section in this example is divided into a support section 11a for the upper strip 3a, a support section 11b for the middle strip 3b, and a support section 11c for the lower strip 3c, each of which is connected to a hydraulic cylinder 12. ,13,14
It is connected to the. These hydraulic cylinders 12, 13, and 14 are placed on a machine stand 15. When attempting to uniformly change the angles of the respective strips 3a to 3c, the hydraulic cylinders 12, 13, and 14 are moved up and down equally.

Moreover, when changing the angle of the strip of a specific stage among the strips 3a to 3c, the corresponding hydraulic cylinders 12, 13, and 14 are driven. Or,
By adjusting the vertical movement distance of these hydraulic cylinders 12, 13, and 14, it is also possible to adjust the opening angle of each adjacent strip. .

Further, the filling state of the raw material layer 5 can also be adjusted by changing the height between the sieve 3 and the raw material layer 5. The kinetic energy of the sintering raw material falling from the sieve 3 toward the raw material layer 5 changes depending on this height. Depending on this kinetic energy, the particles of the sintering raw material constituting the raw material layer 5 may be packed densely or softly, or the particles of the sintering raw material may roll on the inclined surface of the raw material layer 5. Move. This phenomenon is actively utilized to adjust the filling state of the raw material layer 5. At this time, an appropriate means is used to change the height of the sieve 3, so a description using the drawings will be omitted.

Furthermore, the filling state of the raw material layer 5 can be changed by adjusting the positional relationship of the sieve 3 with respect to the chute 2. In other words, sieve 3 is
As described above, a plurality of strips are arranged along the flow direction of the sintering raw material. Therefore, the distance between adjacent strips is smaller as it approaches the operating section 11, and becomes larger as it approaches the tip. Therefore, when the chute is moved, as shown by arrow A in FIG. 1, for example, the spacing between the respective strips when the sintering raw material 1 falling from the chute 2 first hits the sieve 3 also changes. For example, by making the chute split in the axial direction and adjusting the lifting amount (height) of the side and center parts, the classification ability or dispersion ability of the sieve 3 can be changed, and the density meter 6 or industrial camera can be used. The non-uniformity of the raw material layer 5 detected by 10 etc. is eliminated.

In this way, while detecting the actual state of the raw material layer 5 formed on the pallet 4, the sintering raw material 1
In order to control the charging state, it was possible to uniformly perform the sintering reaction on the raw material layer 5 on the pallet.
For example, when raw material layer 5 with a bulk density distribution as shown in Figure 2a was sintered as it was, the sintering yield was 73.4%, but when the classification ability of sieve 3 was controlled. For products, the sintering yield is
This improved to 76.1%.

〔Effect of the invention〕

As explained above, in the present invention, by controlling the charging state of the sintering raw material while detecting the state of the raw material layer formed on the pallet of the sintering machine, even if sintering does not occur during the charging process, Even if there is a change in the particle size distribution of the raw material, a raw material layer that maintains a predetermined air permeability can be formed on the pallet. Therefore, the sintering reaction can proceed uniformly along the width direction of the pallet, and sintered ore can be manufactured with a high yield.

[Brief explanation of drawings]

Fig. 1 is a diagram schematically explaining the charging method of the present invention, Fig. 2 shows an example of the non-uniformity of the raw material layer formed on the pallet, and Fig. 3 shows the non-uniformity of the raw material layer formed on the pallet. An example of a sieve equipped with the function of changing classification ability or dispersion ability is shown below.

Claims (1)

[Claims] 1 Detect the properties of the sintering raw material charged on the pallet of the sintering machine, such as the packing density, air permeability, and fluctuations in red heat, and based on the detected values, extend along the flow direction of the charged raw material. A method for charging sintering raw materials, characterized by automatically controlling the position and/or attitude of a sieve made up of a plurality of strips.