JPH07138663A - Method for charging sintering raw material - Google Patents

Abstract

PURPOSE:To provide a charging method of sintering raw material, in which even in the case of changing the layer thickness of the sintering raw material corresponding to the variation of the gas permeability during operating a sintering machine, the free dropping distance is kept to the constant to stabilize the charged density of the sintering raw material in the prescribed values. CONSTITUTION:The layer thickness and the gas permeability of the sintering raw material charged in a pallet 17 are measured. When this gas permeability changes to the reference gas permeability, the layer thickness is controlled according to the variation of the gas permeability. The charging height of the sintering raw material is changed by shifting a charging device 10 for the sintering raw material to control the charging density of the sintering raw material within the prescribed values. By this method, the stable operation can be executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of charging a sintering raw material, and more specifically, even if the air permeability of the sintering raw material is adjusted by changing the layer thickness of the sintering raw material in a pallet. The present invention relates to a sintering raw material charging method capable of maintaining a set constant sintering raw material charging density.

[0002]

2. Description of the Related Art As a sinter machine, a large number of pallets moving inside the sinter machine are charged with a powder ore dropped from a drum feeder, a coke, and a sinter raw material mixed with limestone powder as required. It is known that the coke is burned while the coke on the surface layer is ignited, the air is sucked downward by a suction device, and the powdered ore is sintered by the heat of the coke. As a charging device used in such a downward suction type sintering machine, for example, a charging device disclosed in "Method for charging sintering raw material" of JP-A-61-223136 has been developed. ing.
This conventional charging device includes a chute that is arranged obliquely below the drum feeder, and a bar screen that is attached to the lower end of the chute and that has a bar screen in which the intervals between the bars gradually widen toward the front side. After the sintering raw material dropped from the drum feeder is tumbled and dropped by a chute to perform coarse grain size segregation, the sintering raw material is finely classified by a bar screen, and the grain size is gradually increased from the lower layer to the upper layer in each pallet. It is charged in a state where the particle size becomes smaller and segregated.

[0003]

By the way, during the operation of the sintering machine, for example, when the air permeability in the sintering bed is changed,
The air permeability (JPU) is controlled by changing the layer thickness of the sintering raw material charged. However, changing the layer thickness inevitably also changes the free fall distance from the charging device to the surface of the raw material packed bed, which changes the charging density of the sintering raw material and makes it possible to control the air permeability as desired. However, there is a problem in that the quality of the produced sinter deteriorates and operation fluctuations occur. The present invention has been made in view of such circumstances, and even if the charging layer thickness of the sintering raw material is changed in response to the change in the air permeability during the operation of the sintering machine, the free fall distance is kept constant and firing is performed. An object of the present invention is to provide a method for charging a sintering raw material, which can stabilize the charging density of the binding raw material within a predetermined value.

[0004]

A method according to the above-mentioned object.
The charging method of the sintering raw material described is such that the sintering raw material dropped from the drum feeder is tumbled by a chute of a charging device that is arranged in an inclined manner, and then the bar is provided at the lower end of the chute. In the charging method of the sintering raw material, in which a plurality of pallets of the lower suction type sintering machine are sequentially charged in a particle size segregation state while classifying with a bar screen whose interval gradually widens toward the front side, The layer thickness and air permeability of the sintering raw material charged in the pallet are measured, and when the air permeability changes with respect to the reference air permeability, the layer thickness is controlled according to the air permeability change amount, and the sintering is performed. By changing the charging height of the raw material by moving the charging device, the charging density of the sintering raw material is controlled within a predetermined value.

[0005]

According to the method for charging the sintering raw material according to claim 1, the layer thickness and the air permeability of the sintering raw material charged in the pallet are measured during the operation of the sintering machine. When the air permeability changes, the layer thickness is controlled according to the air permeability change amount to keep the air permeability constant. In addition to this air permeability control, the charging device is moved up and down or diagonally to change the charging height of the sintering raw material dropped from the charging device, thereby filling the raw material formed in the pallet. By controlling the free fall distance that influences the collision force to the surface of the layer and the particle size segregation state of the sintering raw material that rolls and falls on the chute, the sintering raw material is changed before and after the change of the layer thickness due to the air permeability control. The sintering raw material can be charged into the pallet so that there is no change in the charging density, and stable quality sinter can be produced.

[0006]

Embodiments of the present invention will now be described with reference to the accompanying drawings to provide an understanding of the present invention. 1 is a side view showing a normal operating state of a sintering raw material charging apparatus to which a sintering raw material charging method according to an embodiment of the present invention is applied, and FIG. FIG. 3 is a side view showing a state where the charging height is low, FIG. 3 is a side view showing a state where the charging height of the sintering raw material is high, and FIG. 4 is a block diagram showing a control system of the raw material charging device. FIG. 5 is a graph showing the relationship between the air permeability and the layer thickness of the raw material filling layer filled in the pallet.

As shown in FIG. 1, a sintering raw material charging apparatus 10 to which a sintering raw material charging method according to an embodiment of the present invention is applied is a chute arranged below a drum feeder 11 in an inclined manner. Have twelve. At the lower end of the chute 12, the base portion of the bar screen 13 in which the intervals between the bars gradually widen toward the front side is attached, and the chute 12 moves up and down along a rail 15 inclined by wheels 14. You can do it. The rail 15 is inclined with the traveling direction side of a large number of pallets 17 moving in the sintering machine 16 facing upward, and a stopper 15a for preventing wheel removal is provided at the lower end of the rail 15. ing. Further, the chute 12 is not limited to the vertical movement, but may be moved diagonally, for example.

A winch 18 for moving the chute 12 up and down along the rail 15 is provided above the rail 15. The wire 12 is pulled out from the drum of the winch 18 to lower the chute 12 and the wire to the drum. The chute 12 is pulled up by winding 19 up. Next, the control system of the sintering material charging device 10 will be described in detail with reference to FIG.

As shown in FIG. 4, a sintering raw material charging device 1 is provided.
The control system of 0 includes an air permeability measuring means 21 for measuring the air permeability of the raw material packed layer 20 in the pallet 17 during the operation of the sintering machine 16 and a layer thickness measuring means for measuring the layer thickness of the raw material packed layer 20. 22 and the opening / closing valve 23 of the drum feeder 11 adjust the opening degree to change the layer thickness according to the amount of change in the air permeability, and the air permeability control means 24 for keeping the air permeability constant, and the layer thickness changed. At this time, a chute height control means 25 for moving the chute 12 up and down by the winch 18 so that the charging height (free fall distance) of the sintering raw material from the charging device 10 to the surface of the raw material filling layer 20 does not change. And these control units 26.

Next, a method of charging the sintering raw material according to the present invention using the sintering raw material charging apparatus 10 will be described. Figure 1
As shown in, the sintering raw material dropped from the drum feeder 11 collides with the chute 12 and rolls and falls on the surface thereof,
Coarse grain size segregation takes place here. After that, the sintering raw material is classified by the bar screen 13 so that the particle size gradually increases from the base side to the front side, and the pallets 17 moving in the direction of the arrow in FIG. It is charged in a particle size segregated state in which the particle size gradually decreases. It should be noted that the amount of the sintering raw material charged is set to the preset pallet 17
It is set within the range H of the reference layer thickness of the raw material filling layer 20 (here, the layer thickness H ₁ ), and the charging height of the sintering raw material at this time is set to the value L.

As shown in FIG. 4, during operation of the sintering machine 16,
The air permeability measuring means 21 and the layer thickness measuring means 22 measure the air permeability and the layer thickness of the sintering raw material charged in the pallet 17. When the air permeability changes with respect to the reference air permeability for some reason, the controller 26 outputs an air permeability change signal to the air permeability control means 24, and based on this, the air permeability control means 24 outputs the air permeability change signal to the drum feeder 11. A valve opening / closing command is sent to the opening / closing valve 23 to increase / decrease the amount of raw material dropped from the drum feeder 11, whereby control is performed according to the amount of change in the air permeability of the layer thickness, and the air permeability is kept constant. . When this air permeability control is performed, the layer thickness of the raw material filling layer 20 may largely change from a range centered on a preset value H. Hereinafter, a method for controlling the charging density of the sintering raw material in such a case will be described in detail with reference to FIGS.

FIG. 2 shows the charging density when the layer thickness is increased and the charging height of the sintering raw material is decreased by closing the on-off valve 23 to control the increase in air permeability. Shows the control of. As shown in FIGS. 2 and 4, the layer thickness measuring means 2
2 detects that the layer thickness of the raw material filling layer 20 exceeds the upper limit of the preset reference layer thickness range H (here, layer thickness H ₂ ), the control unit 26 causes the chute height control means 25.
A chute raising signal is issued to the chute 12 and the chute 12 is pulled up by the chute height control means 25 which sends a command to wind the wire 19 to the winch 18. As a result, the charging height of the sintering raw material, which had been lowered, is increased to the reference value L, and the collision force of the sintering raw material on the surface of the raw material filling layer 20 becomes the same as before the air permeability was controlled. The charging density of the sintering raw material is stabilized, good quality and stable quality of sinter can be produced, and fluctuations in operation can be prevented.

FIG. 3 shows the charging density when the layer thickness becomes small and the charging height of the sintering raw material becomes high by controlling the opening / closing valve 23 to control the decrease in air permeability. Shows control. As shown in FIGS. 3 and 4, the layer thickness measuring means 22
When it is detected that the layer thickness of the raw material filling layer 20 is lower than the lower limit of the preset reference layer thickness range H (here, layer thickness H ₃ ), the control unit 26 causes the chute height control means 25 to shoot. A descending signal is issued, and based on this, the chute height control means 25 sends a command to lead the winch 18 to a predetermined amount of the wire 19, and the chute 12 is lowered by a predetermined length. In this way, the charging height of the sintering raw material, which has been increased, is lowered to the reference value L. Thereby, the impact force of the sintering raw material on the surface of the raw material filling layer 20 becomes the same as before the air permeability is controlled. At this time, by lowering the charging device 10, the dropping position of the sintering raw material dropped from the drum feeder 11 on the surface of the chute 12 is moved upward, whereby the transfer of the sintering raw material on the chute 12 is performed. Due to the synergistic effect that the moving distance becomes long, particle size segregation is promoted, and light charging is possible, the charging density can be further reduced.

Next, a sintering raw material charging device 10 shown in FIG.
A charging experiment of a sintering raw material was carried out by using the above, and a change in the charging density when the layer thickness of the raw material packed layer 20 was changed, a change in air permeability and a change in quality were investigated. The experimental results are shown in Table 1.

[0015]

[Table 1]

In the conventional charging device shown in the column of Comparative Example, since the charging height of the sintering raw material is unchanged, the air permeability is 16.
When the air permeability is controlled to reduce the layer thickness of the sintering raw material from 580 mm to 550 mm when it is reduced from 8JPU to 15.8JPU, the free fall distance of the sintering raw material from the charging device to the surface of the raw material filling layer 20 is reduced. The charging density increases from 1.77 T / m ³ to 1.82 T / m ^{3 due} to the increase in the temperature. As a result, even if the air permeability is carefully controlled, the air permeability can be improved only up to 16.1JPU, and the quality of the produced sinter is deteriorated. On the other hand, in the case of the charging device 10 of the embodiment, since the charging height can be changed, the charging device 10 can be lowered to adjust the charging height even if the air permeability control for reducing the layer thickness is performed. By doing so, the charging density is maintained at 1.77 T / m ³ as before. As described above, since the air permeability and the charging density did not change before and after changing the layer thickness, the quality of the sintered ore did not change and stable operation was possible.

FIG. 5 is a graph showing the relationship between the air permeability and the layer thickness when the charging density is used as a parameter. When the charging density is constant as in the sintering raw material charging device 10 of this embodiment, the relationship between the air permeability and the layer thickness is directly proportional as shown by the solid line a in the figure. However, in the case of the conventional charging device, since this device is fixed at a predetermined height position, if the layer thickness is changed, the free fall distance changes and the charging density also changes as shown by the chain line b in the figure. Change. As a result, it is clear from this graph that when the layer thickness becomes small as in the above experiment, the charging density tends to increase and the air permeability improving effect tends to decrease. The intersection P between the solid line a and the chain line b indicates the planned installation layer thickness of the charging device.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and the invention is included in the present invention even if there are design changes and the like without departing from the scope of the invention. For example, in the embodiment, the winch is shown as the means for moving the charging device up and down, but the present invention is not limited to this, and a cylinder such as an air cylinder or a screw feed mechanism may be adopted.

[0019]

In the method for charging the sintering raw material according to the first aspect of the present invention, when the layer thickness of the raw material filling layer is changed in order to control the air permeability of the sintering raw material charged in the pallet in this way, ,
By moving the charging device so that the charging height from this device to the surface of the raw material packed bed is constant, the charging density of the sintering raw material is stabilized before and after the air permeability control, which ensures a constant quality. Sintered ore can be produced and stable operation is possible.

[Brief description of drawings]

FIG. 1 is a side view showing a normal operating state of a sintering raw material charging apparatus to which a sintering raw material charging method according to an embodiment of the present invention is applied.

FIG. 2 is a side view showing a state in which the charging height of the sintering raw material is lowered.

FIG. 3 is a side view showing a state where a charging height of the sintering raw material is increased.

FIG. 4 is a block diagram showing the control system.

FIG. 5 is a graph showing the relationship between the air permeability and the layer thickness of the raw material packed bed packed in the pallet.

[Explanation of symbols]

 10 Sintering Raw Material Charging Device 11 Drum Feeder 12 Chute 13 Bar Screen 14 Wheel 15 Rail 15a Stopper 16 Sintering Machine 17 Pallet 18 Winch 19 Wire 20 Raw Material Packing Layer 21 Air Permeability Measuring Means 22 Layer Thickness Measuring Means 23 Opening / closing Valve 24 Air permeability control means 25 Chute height control means 26 Control section

Claims (1)

[Claims] 1. A sinter raw material dropped from a drum feeder is rolled and dropped by a chute of a charging device which is arranged in an inclined manner, and is provided at the lower end of the chute so that the intervals between the bars are forward. In the charging method of the sintering raw material, in which a large number of pallets of the lower suction type sintering machine are sequentially charged in a particle size segregated state while being classified by a bar screen that gradually widens toward the pallet. The layer thickness and the air permeability of the sintering raw material are measured, and when the air permeability changes with respect to the reference air permeability, the layer thickness is controlled according to the amount of change in the air permeability, and the charging height of the sintering raw material is increased. Is controlled by moving the charging device to change the charging density of the sintering raw material within a predetermined value.