JPH0816250B2 - Sintering raw material charging method and charging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention, when producing a sinter used as a blast furnace charging raw material, has a predetermined grain size segregation to give a sinter raw material to a pallet of a sintering machine. The present invention relates to a charging method and a charging device used in the method.

[Conventional technology]

In the method of producing a sintered ore from iron ore raw materials such as powdered ore, coke having an appropriate particle size is mixed with iron ore powder of about 10 mm or less and limestone powder as needed, and the mixture is supplied to a sintering pallet. Was there. Then, the coke on the surface layer of the supplied sintering raw material is ignited, the coke is burned while sucking air downward, and the powder ore is sintered by the combustion heat generated at this time. Here, when the sintering raw material is distributed with a uniform particle size distribution along the height direction of the sintering raw material, due to the heat transfer inside the raw material layer, the temperature becomes lower in the lower portion of the raw material layer and the ventilation resistance increases. . Further, in the surface layer portion, the sintered raw material is cooled by the sucked outside air, and the temperature rise becomes insufficient, resulting in incomplete sintering.
As a result, the strength of the sinter is reduced, and when post-treatment such as crushing and sieving is performed, the proportion of the pulverized powder that is not used as a blast furnace charging material increases.

In order to avoid this drawback, a method of forming a raw material layer with coke segregation in which the grain size of the surface layer portion is made fine and the grain size of the lower layer portion is made large, and the coke also has many upper layers and less lower layer according to this grain size segregation is formed on the pallet. Various proposals have been made. The most commonly used means for forming a raw material layer having such particle size segregation is a chute method using an inclined plate or the like. However, in this chute method, the particle size segregation of the obtained raw material layer is not sufficient.

Therefore, Japanese Patent Application Laid-Open No. 61-60834 discloses that a chute is formed by inclining and tensioning a plurality of wire ropes. When the sintering raw material is supplied to this chute, the fine-grained portion passes through the chute and is sent onto the pallet to form the surface layer portion of the raw material layer. On the other hand, the coarse-grained portion that does not pass through the chute is fed along the inclined surface of the chute and forms the lower layer part of the raw material layer.

[Problems to be solved by the invention]

When charging the sintering raw material according to the description of JP-A-61-60834, the sintering raw material is divided into an upper sieve and a lower sieve,
Each is the upper layer part and the lower layer part of the raw material layer on the pallet. For this reason, the grain size changes discontinuously between the upper layer portion and the lower layer portion, which is still insufficient for stable aeration and uniform sintering throughout the raw material layer. Further, since the two-stage classification is performed on the sieve and under the sieve, carbonaceous materials such as coke having a small particle size can be collected in the upper layer, but the classification ability is small and the coke segregation is not sufficient. for that reason,
The ventilation resistance still did not meet the intended setting, local overheating and low-temperature parts were generated, and it was unavoidable that the sintering finish of the raw material became non-uniform, and the sintering yield was low.

Therefore, the present inventors distributed the sintering raw material according to its particle size under stable conditions and sent it to a sintering pallet without uniformly classifying the sintering raw material into a sieve and a sieve. In order to enable various sintering reactions, a charging method and charging device as shown in FIG.
Application has been filed as 64677 (Japanese Patent Laid-Open No. 61-223136).

In the charging method shown in FIG. 3 (a), the sintering raw material 1 to be charged is stored in the hopper 2, and is successively fed by the conveying means such as the drum feeder 3 or the like to the chute 4 such as an inclined plate.
And is conveyed to the charging device 5. This charging device 5 is provided with a plurality of rod-shaped members 6 along the conveying direction of the sintering raw material 1. One end of each of the bar members 6 is attached to the bar member mounting position 4a of the chute 4, and the other end is attached to the lower end mounting plate 7. A plurality of holes for inserting the lower end portions of the bar members 6 are formed on the lower end mounting plate 7 side. This hole and upper mounting position 4a
Thus, each bar is maintained in the inclined state shown in FIG.

That is, the difference between the inclination angle alpha ₂ of the inclination angle alpha ₁ Like second bar cord member 6b of the first rod strip material 6a with respect to the horizontal plane (alpha
_{2-.alpha. 1),} the second difference of the inclination angle of the bar strip material 6b alpha ₂ and an inclination angle alpha ₃ of third bar cord member 6c (α ₃ -α _2), third bar cord member 6c inclination angle alpha ₃ and the inclination angle alpha ₄ of fourth bar cord member 6d
Difference (α ₄ −α ₃ ), the inclination angle α _{4 of} the fourth bar 6d
And the inclination angle α ₅ of the fifth bar 6e (α ₅ −α ₄ )
It becomes smaller in order.

As a result, particles with the same particle size will be
From the position P ₁ closest to the first bar 6a and the second bar 6b
It passes through the gap between and and falls on the pallet 8 of the sintering machine. Further, at a position P ₂ slightly lower than the position P _1, it passes through the gap between the second bar material 6b and the third bar material 6c and falls onto the pallet 8. Similarly, at the position P ₃ from the gap between the third rod member 6c and the fourth rod member 6d, the gap between the fourth rod member 6d and the fifth rod member 6e. At position P ₄ , particles having the same particle size fall onto the pallet 8. As a result, particles having the same particle size are classified from the sintering raw material 1 and sent to the pallet 8 in the range L ₁ from the bar-shaped material mounting position 4a. This sintering raw material 1
By charging the particles over the range L _1, for example, small particles accompanied by large particles can be reliably selected, and classification accuracy is improved.

Further, for example, at the position P ₄ , small-diameter particles fall from between the fourth rod member 6d and the fifth rod member 6e, and at the same time, the first rod member 6a and the second rod member 6b are simultaneously pressed. Particles of relatively large diameter fall from between. Then, the ratio of the large-diameter particles to the small-diameter particles continuously increases toward the lower side of the bar material 6. Therefore, the raw material layer 9 formed on the pallet 8
There is no discontinuity in the particle size distribution of.

The present invention was developed to further enhance the action of the mountain-shaped charging device formed by arranging the bar members in an inclined manner as described above, and by improving the shape of each bar member, the same It is an object of the present invention to lengthen a range L ₁ through which particles having a particle diameter pass through a sieve surface to enhance classification efficiency and form a raw material layer in which segregation of a sintering raw material and coke is reinforced.

[Means for solving problems]

The raw material charging method of the present invention, in order to achieve the purpose,
A plurality of bar materials curved downwardly in a convex shape are arranged at different inclination angles so that at least the lower side has a single or a plurality of mountain shapes, and the sintering raw material is placed through the sieve surface formed by these bar materials. Is supplied on a sintering pallet.

Further, a classifying device for carrying out this method is a charging device having a plurality of bar members inclinedly arranged and having a sieve surface formed by the plurality of bar members, wherein the bar members are directed downward. It is characterized in that it is curved in a convex shape and arranged at different inclination angles so that at least the lower side forms a single or a plurality of mountain shapes.

〔Example〕

Hereinafter, the features of the present invention will be specifically described by way of examples with reference to the drawings.

FIG. 1 is a view of the arrangement state of the bar members in the charging device according to the present embodiment as seen from the lateral direction. In addition, in this embodiment, one mountain-shaped slope is composed of three bar members 6a to 6c, but the number of constituents may be appropriately changed.
Further, since the charging device shown in FIG. 3 is used as the charging device excluding the arrangement of the bar material, the reference numerals of the same figure are used in the following description.

Each of the bar members 6a to 6c is curved downward with a proper curvature. Due to this curve, the gap between the bar 6a that hits the top of the chevron and the bar 6b in the center a ₁ and the gap between the bar 6c that hits the bottom of the chevron and the bar 6b in the center
The rate of change in which b ₁ and B spread toward the lower side is smaller than when a straight bar material is used. Also on the lower end mounting plate 7 side, when a straight bar material is used, the gap a _{0 between the} bar materials 6a to 6b and the bar material 6b to
For the gap b _{0 of} 6c, a ₁ <a ₀ and b ₁ <b ₀ . In addition,
The lower end portions of the bar members 6a to 6c may be free ends without being fixed to the lower end mounting plate 7.

Therefore, the range L ₁ in which particles having the same particle size are classified from the supplied sintering raw material 1 and pass through the charging device becomes long,
The classification efficiency is improved. As a result, segregation in the formed raw material layer 9 is strengthened, and low density packing is possible.

FIG. 2 shows a bar member 6a curved downwardly in a convex shape.
It is a gulf showing the particle size distribution in the raw material layer 9 when the sintering raw material 1 is classified using ~ 6c.

In this example, the bar members 6a to 6c on the lower end mounting plate 7 side
Gaps were set to a ₁ = 15 mm and a ₂ = 30 mm. Also, bar material 6a
As for ~ 6c, a round steel rod with a diameter of 10 mm and a length of 700 mm has a radius of 4000 m
What was curved in the shape of an arc toward the bottom of m was used, and this was stretched between the bar material mounting position 4a and the lower end mounting plate 7. The vertical distance between the bar material mounting position 4a and the lower end mounting plate 7 was 550 mm.

With such specifications, the sintering raw material 1 having a thickness of 10 mm or less was supplied to the pallet 9 of the sintering machine to form the raw material layer 9 having a thickness of 500 mm. The raw material layer 9 has a gentle inclination when viewed in the thickness direction, as shown by the solid line in FIG.
It is understood that is supplied onto the raw material layer 9. On the other hand, a case where the sintering raw material 1 was charged by using a charging device made of a straight bar material was used as a comparative example. In this comparative example, the sintering raw material 1 that has passed through the charging device has a relatively steep inclination angle as indicated by the alternate long and short dash line in FIG.

As described above, according to the present embodiment, the particles having a uniform particle size are arranged in the height direction of the raw material layer 9 and are dispersed and dropped, so that the bulk density of the raw material layer 9 is also reduced. For example, the bulk density in the comparative example was 1.89 on average over the entire thickness of the raw material layer 9, whereas it was 1.87 in the case of this example. Due to this difference in bulk density, the raw material layer 9 obtained in this example had good air permeability, and the sintering reaction in each part of the raw material layer 9 proceeded quickly and efficiently.

Also, bar members 6a to 6c that are convexly curved downward
When using, the vertical kinetic energy of the sintering raw material 1 falling from the chute 4 becomes smaller as it rolls on the inclined surface formed by the bar members 6a to 6c. Therefore, as compared with the case of passing through a charging device made of a straight rod-shaped material, the impact given to the raw material layer 9 is reduced, and the avalanche phenomenon on the slope of the raw material layer 9 being formed is suppressed. It Therefore, the sintering raw material 1 that has passed through the charging device
Is a pallet 8 without breaking its particle size distribution.
Supplied on.

In the above example, the case where the end portions of the bar members 6a to 6c on the bar member mounting position 4a side have the same height has been described. However, it goes without saying that the present invention is not restricted to this. For example, it is also possible to hold the ends of the bar members 6a to 6c on the bar member mounting position 4a side in a mountain shape corresponding to the mountain shape of the lower end mounting plate 7 side or a mountain shape in the inverted state. .

Further, the mutual gaps a ₁ and b ₁ of the bar members 6a to 6c can be made smaller toward the lower part of the mountain shape. When the mutual gaps a ₁ and b ₁ are changed in this way, the range L ₁ in which particles having the same particle size are classified is further increased, and the classification efficiency is further improved.

Furthermore, the charging device composed of the bar members 6a to 6c can be arranged in multiple stages. In this case, it is preferable to shift the cycle of the ridges so that the tops of the lower ridges come to the bottoms of the upper ridges. As a result, the flow rate distribution of the sintering raw material falling from the lower charging device becomes uniform along the width direction.

〔The invention's effect〕

As described above, in the present invention, by bending the bar material constituting the charging device in a downward convex shape, the range in which particles of the same particle size pass through the sieving surface is lengthened, Improves classification efficiency. The particle size distribution of the raw material layer thus obtained is gradually inclined along the thickness direction, and the bulk density is low. In addition, the segregation of the sintering raw material is accompanied by an increase in the distribution of coke in the upper layer. Therefore, the air permeability of the raw material layer is improved, and the sintering reaction can be performed efficiently and quickly.

[Brief description of drawings]

FIG. 1 shows the arrangement state of the bar material in the embodiment of the present invention, and FIG. 2 is a graph specifically showing the effect of the present invention. Further, FIG. 3 shows a raw material charging device separately developed by the present inventors.

Claims (2)

[Claims] 1. A plurality of bar-shaped members curved downwardly convexly are arranged at different inclination angles so that at least the lower side has a single or a plurality of mountain-shaped members, and the sieve surfaces formed by these bar-shaped members are arranged. A method for charging a sintering raw material, characterized in that the sintering raw material is supplied onto a sintering pallet via the sintering raw material. 2. A charging device having a plurality of bar members inclinedly arranged and having a sieve surface formed by the plurality of bar members.
A charging device, wherein the bar members are curved downwardly in a convex shape, and are arranged at different inclination angles so that at least the lower side forms a single or a plurality of mountain shapes.