JPH0668137B2 - Raw material charging control method for sintering machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention, in a DL type sintering machine, makes uniform the heat history in the width direction of the sintering pellet of the compounded raw material charged in the sintering pellet. The charging method of the sintering raw material as described above.

(Prior Art) In a continuous downward suction sintering machine, a raw material charging hopper provided on the starting end side of an endless pallet that circulates is first charged with a compounding raw material, and a drum feeder is fed from a gate of the charging hopper. The compounded raw material is cut out in a fixed amount by this and supplied onto the pallet. The raw material (referred to as filling raw material) charged in the pallet is ignited on its surface as it passes through the ignition furnace, and is taken in by an exhaust fan through the wind box,
The raw material is fired while ventilating from the upper layer to the lower layer of the filling material layer, and the firing of the raw material is completed before reaching the mine ore section, and it is discharged as sinter ore from the pellet in the mine section.

Since sinter is used in the largest amount as a blast furnace charge, it is important to reduce the manufacturing cost assuming stable quality such as its cold strength (SI) and reduction powderability (RDI). is there. In order to reduce the manufacturing cost of the sintered ore, it is important to increase the ratio of the product sintered ore to the sintered ore sintered on the sintered pellet (hereinafter referred to as the sintered yield). is there.

The air flow resistance during firing of the packing material on the pallet greatly affects the sintering yield, but the air permeability of the packing material in the width direction of the sinter pallet depends on the wall effect between the side wall and the packing material. Inside the sinter pallet due to the decrease, the grain size of the blended raw material supplied from the charging hopper tends to become coarse at both ends of the sinter pallet, and the presence of air leakage between the sinter pallets. Both ends of the filling material are excessive in air permeability as compared with the central part, and the air volume during firing increases and becomes excessive. This means that the thermal history (temperature curve) in the packing material layer at both ends begins to rise earlier than in the central part and the firing is completed earlier, resulting in maintaining the sintering yield. In order to do so, the high temperature holding time in the layer during firing was remarkably reduced at both ends, which was a major cause of reduction in sintering yield.

For this reason, in the past, in order to eliminate the decrease in the sintering yield at both ends of the sintered pallet, when the compounding raw material was charged into the charging hopper, fine particles were formed at both ends in the width direction of the sintered pallet and coarse particles were formed at the center. There is a method of segregation charging so that it can be charged, but to what extent it is appropriate to add particle size segregation in the width direction of the sintered pallet, there is no reference information, and it is possible to cope with daily operation fluctuations It is hard to say that it is a control system. Also, as a method of controlling the packing density in the width direction of the sintered pallet, when cutting the blended raw material from the charging hopper, it is divided into the cutting gate in the width direction of the sintered pallet and the amount of the raw material blended is cut out for each cutting gate. Of the exhaust gas temperature pattern in the width direction of the sintering pallet by eliminating the difference in the exhaust gas temperature pattern in the width direction of the sintering machine. To control the cut-out amount of the blended raw material so that
29590 publication). However, since the exhaust gas temperature of the wind box is affected by the leakage of air from the seal portion between the lower part of the sintering pallet and the window box, it cannot be said that the firing status in the width direction of the sintering pallet is always displayed accurately. In addition, since the exhaust gas temperature on the mine ore side in the advancing direction of the sintering machine is detected and controlled, a satisfactory control effect such as a time delay in the control system is not obtained.

In other words, the method of charging the compounded raw materials into the sintering pallet that is currently being carried out, considering the filling state in the width direction of the sintering pallet, does not necessarily mean that the filling structure of the raw material is a uniform firing due to the daily operation fluctuations. It was not controlled by the packing density, and as a result, a decrease in the sintering yield was unavoidable at both ends of the sintered pallet.

(Problems to be Solved by the Invention) The present invention solves such a problem, and when a sintering compounding raw material is charged onto a sintering pallet, the sintering yield due to excessive ventilation at both ends of the sintering pallet is increased. Provided is a method for charging a sintering raw material, in which the decrease is improved by appropriately controlling the packing density in the width direction of the sintering pellet.

(Means for Solving Problems) The present invention provides a sintering compound raw material charging method in which a sintering compound material is cut out from a charging hopper and charged into a sintering pallet.
The cutting gate of the charging hopper is divided into at least three in the width direction of the sintering pallet, and the feed amount of the mixed raw material in each divided gate can be adjusted, and the filling density of the filling raw material can be adjusted on the sintering pallet below the drum feeder. Detected in correspondence with each gate divided by the γ-ray densitometer,
It is characterized in that the compounding raw material supply amount of each gate divided so that the packing density distribution of each gate detected by the γ-ray densitometer becomes equal to the packing density distribution in the width direction of the preset sintered pallet is adjusted. It is a raw material charging control method for a sintering machine.

(Operation) In the present invention, for example, as shown in FIG. 2 and FIG. 3, at least three points or more in the width direction of the sintering pallet are provided inside the cutting gate 3 provided at the raw material cutting opening of the charging hopper 1. The divided gate 4 is provided, and the hydraulic cylinder 5 is operated and adjusted to move the divided gate 4 up and down, whereby the amount of the mixed raw material supplied to each of the divided gates can be increased or decreased.

The number of divisions of the division gate 4 and the division distance should be determined according to the characteristics of the packing density in the pallet width direction of the sintering machine and the characteristics of the cutting raw material in the pallet width direction. It is essential to divide it into at least three or more.

Further, in the present invention, as shown in FIGS. 1 (a) and 1 (b), the gamma ray densitometer 7 is inserted corresponding to each gate divided into the filling raw material 12 below the drum feeder 2 and divided. The filling density can be detected for each gate. Subsequently, the detected γ-rays are collected by the signal processing device 8 for each signal processing time set in advance, and the γ-ray count number (count value) is collected and communicated to the arithmetic processing device 9. In the processing unit 9, the signal processing unit 8
The packing density is obtained based on the calibration curve set in advance from the γ-ray count number from the above, and the packing density difference in the sintering pallet width direction set from the width direction packing density difference setting board 10 and the actually measured gate The difference in the filling density difference for each is obtained, and the opening control amount of the split gate required to make the measured filling density difference equal to the set filling density difference is obtained. Subsequently, the control device 11 controls the hydraulic cylinder 5 by a predetermined control amount based on the obtained split gate control amount, and adjusts the opening degree of the split gate 4 for each gate.

The installation position of the γ-ray density meter 7 in the width direction of the sintered pallet is
In consideration of adjusting the blended raw material supply amount for each gate based on the detected packing density, it is desirable to install it at the center of each divided gate 4. Further, in the direction of the height of the sintered bed, it is desirable to install it in the central part in the sense that the average value is detected at each position in the width direction of the sintered pallet. However, since the center portion does not always show the average packing density in the sintered bed height direction, basically, the packing density distribution in the sintered bed height direction is grasped and determined. Should be.

The reason for using γ-rays when measuring the packing density of the blended raw material is as follows. The purpose of controlling the packing density of the sintering compound raw material in the width direction of the sintering pellet is to optimize the ventilation resistance of the sintering compound material in the width direction of the sintering pellet. That is, basically, it is desirable to detect the actual condition of the ventilation resistance in the width direction of the sintered pallet. However, ventilation resistance, packing density,
Since it is closely related to the particle size, ventilation resistance, packing density,
The information is sufficient if any of the particle sizes can be detected.

As a conventional method for measuring ventilation resistance, there is a method in which a ventilation pipe is inserted into the filling material layer, air is blown, and the ventilation resistance is measured by the back pressure thereof. It is difficult to obtain the required accuracy due to the adhesion. There is also a method of detecting the gas flow rate in the width direction of the sintered pallet to obtain the ventilation resistance, but there is a problem in accuracy because it is affected by air leakage between the lower part of the pallet and the wind box. In addition, as a method for detecting the particle size, there is a method using image processing, η wave, and a high-speed camera. In each method, the sintering compound raw material is charged into the sintering pellet through the sloping shout. Since this is to detect the surface on which the particles of the raw material are rolling, that is, the surface of the so-called moving layer, it cannot be said that the information is in the sintering bed of the charged raw material actually charged, and there is a problem in accuracy.

In contrast to these methods, the method of detecting the packing density with a γ-ray densitometer eliminates the problem of accuracy due to the density of the actually inserted part being detected and the adhesion of raw materials in the measuring method using a ventilation pipe. According to the investigation results of the present inventors, the detection accuracy required for the γ-ray densitometer can be sufficiently satisfied.

As described above, in the present invention, the packing density of each of the divided gates is detected immediately after the mixed raw material is charged into the sintering pallet, and the packing density difference of each gate at that time is detected. To operate the split gate by manual or automatic control,
Increase or decrease the amount of material cut out for each gate. As a result, the packing density in the width direction of the sintered pallet of the packing material charged in the sinter pallet becomes an appropriate value. As a result, the ventilation resistance in the width direction of the sintered pallet is optimized, the uneven heat history during firing in the width direction of the sintered pallet is reduced, and the sintering yield at both ends of the sintered pallet is reduced. Is avoided.

(Example) As shown in FIG. 4, the dividing gate 4 for controlling the packing density in the width direction of the sintered pallet was provided so as to have a symmetrical structure in the width direction of the sintered pallet. Sintered pallet width 3500 mm at both ends
It was divided into 5 parts with 250 mm and 1000 mm on the center side.

The γ-ray density meter 7 was installed at the center of each divided gate 4 in the width direction of the sintered pallet and at the center of the layer thickness in the height direction of the sintered bed.

The results of the investigation of the sintering yield distribution on the cross section of the sintered pallet before and after the present invention are carried out are shown in FIGS. Before carrying out the present invention, as shown in FIG. 5 (a), the sintering yield at both ends of the sintered pallet is remarkably reduced.
As shown in (b), the sintering yield at both ends of the sintered pallet is improved, and the sintering yield of the cross section of the sintered pallet is improved. In this way, the amount of raw material cut out from the split gate 4 is controlled so that the filling density of the filling raw material in the width direction of the sintered pallet is controlled, so that the thermal history during firing in the width direction of the sintered pallet is reduced. It has been made uniform, and the sintering yield can be improved.

(Effects of the Invention) As described above, according to the present invention, it is possible to improve the sintering yield in the pallet width direction, and thus improve the overall sintering yield. .

[Brief description of drawings]

1 (a) and 1 (b) are a sectional view and a front view of an example of a blended raw material charging section used in the method of the present invention, FIG. 2 is a sectional view of a split gate, and FIG. 3 is a front view of a split gate. Fig. 4 is a cross-sectional view of the blended raw material charging part in the embodiment of the present invention, and Figs. 5 (a) and 5 (b) are the results of the investigation of the sintering yield distribution in the cross section of the sintered pallet before and after the present invention. It is a figure which shows the comparison of. DESCRIPTION OF SYMBOLS 1 ... Charging hopper, 2 ... Drum feeder, 3 ... Cutting gate, 4 ... Dividing gate, 5 ... Hydraulic cylinder, 6 ... Sloping plate, 7 ... γ-ray density meter, 8 ... Signal processing device, 9 ... Arithmetic processing device 10 ... Width direction packing density difference setting board, 11 ... Control device, 12 ... Packing raw material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroshi Nishikawa, 1 Kimitsu, Kimitsu-shi, Chiba Nippon Steel Co., Ltd. Inside the Kimitsu Works (72) Inventor, Katsuhiko Yui, 1 Kimitsu, Chiba Prefecture Nippon Steel Corporation Kimitsu In-house (56) Reference JP 61-7450 (JP, A) JP 58-115351 (JP, A) JP 60-91184 (JP, A)

Claims (1)

[Claims] 1. A method for charging a sintering compound material, which comprises cutting a sintering compound material from a charging hopper and charging it into a sintering pallet, wherein a cutting gate of the charging hopper is divided into at least three in the width direction of the sintering pallet. It is possible to adjust the blended raw material supply amount in each of the divided gates, and detect the filling density of the filling raw material in correspondence with each gate divided by the γ-ray density meter on the sintering palette below the drum feeder, It is characterized in that the compounding raw material supply amount of each gate is adjusted so that the packing density distribution of each gate detected by the γ-ray densitometer becomes equal to the packing density distribution in the width direction of the preset sintered pallet. Raw material charging control method for sintering machine.