JPS6345327A - Method for controlling charging of raw material to sintering machine - Google Patents

Abstract

PURPOSE:To control the raw material density in the transverse direction of a sintering pallet and to improve the product yield of sintered ore for a blast furnace by detecting the raw material density on the pallet, comparing the same with a set density and controlling the opening of divided gates of a drum feeder at the time of producing the sintered ore with a DL type sintering machine. CONSTITUTION:A raw material feeding gate 3 is formed of >=3 pieces of the divided gates 4 and gamma ray density meters 7 are inserted into the packed raw materials on the pallet corresponding thereto at the time of feeding the sintering raw material in a charge hopper 1 of the DL type sintering machine and igniting the material to sinter the same. The raw material density in the transverse direction of the pallet detected by the density meters 7 is inputted to a signal processor 8 which compares the number of the gamma ray counts determined by the same and the difference of the packing density in the transverse direction of the sintering pallet from a setting board 10 for the difference of the packing density in the transverse direction of the pallet. The opening of the divided gates 4 is so adjusted by a control device 11 to adjust the difference equal to the set density difference. The thermal hysteresis at both ends in the transverse direction of the pallet is uniformized over the entire part in the transverse direction, by which the sintering yield of the packed raw material is improved.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention, in a DL type sintering machine, uniformizes the thermal history of mixed raw materials in the width direction of the sintered pallet when charged into the sintered pallet. I am impressed by the method of charging raw materials for sintering.

(Prior art) In a continuous downward suction sintering machine, all blended raw materials are once charged into an FC raw material charging hopper, which is installed at the starting end of an endless noglet that circulates, and the raw materials are fed from the gate of this charging hopper. A drum feeder cuts out a fixed amount of raw materials and supplies them onto a pallet. When the fc raw material charged into the pallet (referred to as the filling raw material) passes through the ignition furnace, it is ignited on the surface, and air is sucked in by the exhaust fan through the entire wind system, and the FC raw material (referred to as the filling raw material) is ignited from the top of the filling raw material layer to the bottom. The raw material is fired while being aerated over the nozzle, and the firing of this raw material is completed before it reaches the ore discharge section, where it falls as sintered ore and is discharged.

Since sintered ore is used in the largest amount as a charge for flat furnaces, it is important to ensure stable quality such as cold strength (SI) and reduction pulverizability (RDI), which is important for reducing manufacturing costs. be. In addition, when measuring the manufacturing cost of sintered ore, it is important to increase the ratio of finished sintered ore to the sintered ore fired on the sintering pallet (hereinafter referred to as sintering yield). That's true.

The sintering yield is greatly influenced by the ventilation resistance of the filling material on the pallet during firing, but the ventilation resistance of the filling material in the width direction of the sintered pallet is affected by the wall effect between the sidewall and the filling material. to decline.

The particle size of the blended raw material supplied from the charging hole A- tends to become coarser at both ends of the sintered nocelet, and the presence of air leakage between the pallets due to sintering and the like. Compared to the center, both ends have excessive air permeability, so the air volume during firing increases and becomes excessive. This means that the thermal history (temperature curve) in the packed raw material layer at both ends starts to rise in temperature earlier than in the center, and sintering is completed earlier, thus maintaining the sintering yield. The time needed to hold the layer at high temperature during firing, which is required to achieve this, is significantly reduced at both ends, which is a major cause of a decrease in sintering yield.

For this reason, conventionally, in order to eliminate the decrease in sintering yield at both ends of the sintering pallet, when charging the mixed raw materials into the charging hopper, in the width direction of the sintering pallet, fine grains were formed at both ends and coarse grains were formed at the center. There is a method of segregation charging so that grains are charged, but there is no standard information on how far it is appropriate to create grain size segregation in the width direction of the sintered pallet, and this method is suitable for daily operational variations. It is difficult to say that it is a control system that can be used. In addition, as a method of controlling the packing density in the width direction of the sintered pallet, when cutting out the mixed raw materials from the charging hopper, the cutting gate is divided in the width direction of the sintered pallet, and the cutting density of the mixed raw material is controlled at each cutting gate. A thermocouple is installed in the wind box so that the exhaust gas temperature pattern in the sintering machine movement direction in the width direction of the sintering pallet can be adjusted. A method of controlling the cutting rate of blended raw materials so as to eliminate the difference (for example, 1% Kasho 6
0-129590, etc.). However, since the exhaust gas temperature of the wind box is affected by air leakage from the seal between the lower part of the sintering pallet and the wind box, it is difficult to say that the firing status in the width direction of the sintering pallet is always accurately displayed. In addition, since the temperature of the exhaust gas on the discharge side of the sintering machine is detected and controlled, a time delay occurs in the control system, and a satisfactory control effect cannot be obtained.

In other words, the currently available method of charging compounded raw materials into sintered pallets does not necessarily result in uniform firing of the raw material packing structure under daily operational fluctuations, considering the filling state in the width direction of the sintered pallets. The packing density is not controlled, and as a result, a decrease in sintering yield at both ends of the sintering pallet is unavoidable (Problem to be Solved by the Invention) The present invention solves this problem. , Sintering that improves the reduction in sintering yield due to excessive ventilation at both ends of the sintering pallet by appropriately controlling the packing density in the width direction of the sintering pallet when charging the sintering compound raw materials onto the sintering pallet. Provide a method for charging raw materials.

(Means for Solving the Problems) The present invention provides a method for charging sintered raw materials by cutting out sintered raw materials from a charging hopper and charging them into a sintering pallet.
The cutting gate of the charging hopper is divided into at least three or more parts in the width direction of the sintering pallet, and the amount of raw material supplied at each divided gate can be adjusted, and the packing density of the raw material can be adjusted from drum to drum. Filling in the width direction of the sintered pallet is detected on the sintered pallet below the sintered pallet by the l-linear densitometer and detected in correspondence with each gate, and the packing density distribution of each gate detected by the r-linear densitometer is set in advance. This is a raw material charging control method for a sintering machine characterized by adjusting the amount of mixed raw material supplied to each divided gate so as to be equal to the density distribution.

In addition, a dividing gate 4 divided into at least three points in the width direction of the sintering pallet is provided inside the cutting gate 3 provided at the raw material cutting opening of the charging hopper 1.

By adjusting the hydraulic cylinder 5 in VJJ, the divided gate 4 is raised and lowered, thereby making it possible to increase or decrease the amount of raw materials supplied to each divided gate.

The number of divisions and the division distance of the division gate 4 should be determined based on the characteristics of the packing density in the width direction of the pallet of the sintering machine and the characteristics of the cut raw material in the width direction of the A-let. It is essential to divide it into at least three parts.

Furthermore, in the present invention, as shown in FIGS. 81 (() and (b), a γ-ray densitometer 7 is inserted corresponding to each gate divided into the filling material 12 below the drum feeder 2, and minute='l The packing density can be detected for each gate.VC
Then, the signal processing device 8 detects the K gamma ray count (count value) per preset signal processing time by 1.
and communicates to the arithmetic processing unit f9. The arithmetic processing unit f9 calculates the packing density from the rm quant number from the signal processing unit 8 based on a preset calibration curve, and also calculates the width direction light j! Filling density difference in sintered pallet Kagata set from Aff1 degree difference setting board 10 and! 6+11, the difference in the filling density difference for each gate is determined, and the opening control amount of the divided gates required to make the measured filling density difference equal to the set light 8u degree difference is determined. Subsequently, the control device 11 controls the hydraulic cylinder 5 by a predetermined control amount using the obtained divided gate control amount, and adjusts the opening degree of the divided gate H for each gate.

The installation position of the γ-ray density meter 7 is as follows in the width direction of the sintered pallet:
Considering that the amount of mixed raw materials supplied for each gate is adjusted based on the detected filling degree, it is desirable to install it at the center of each dividing gate 4. Also, in the sintering bed height direction, each It is desirable to install it at the center in order to detect the average value at the position in the width direction of the sintered pallet.

However, since the center does not necessarily indicate the average packing density in the height direction of the sintered propeller, it is basically necessary to understand the packing density distribution in the height direction of the sintered pellet. The decision should be made based on the

The reason why R-rays were used to measure the packing density of the blended raw materials is as follows. The purpose of controlling the packing density of the sintering compound raw material in the width direction of the sintering hole is to optimize the ventilation resistance in the sintering and let width direction of the sintering compound raw material.

First, it is basically desirable to detect the actual state of airflow resistance in the width direction of the sintered pallet.However, airflow resistance, filling''
8! Since there is a close relationship with density and particle size, it is sufficient information if either ventilation resistance or packing density of the five particle sizes can be detected.

Conventional methods for measuring ventilation resistance include ventilation within the packed raw material layer. There is a method of measuring ventilation resistance by inserting a tube and blowing air and measuring the back pressure, but it is difficult to obtain the required accuracy due to the material adhering to the ventilation hole. There is also a method of determining the ventilation resistance by detecting the gas flow rate in the width direction of the sintered pallet, but this method has problems with accuracy due to the influence of air leakage between the lower part of the pallet and the first index. In addition, image processing, η waves,
There is a method using a high-speed camera, but in both methods, the sintered compounded material passes through the sloping chute and is charged into the sintering nocelet.The surface where the particles of the sintered compounded material are transferred, the surface of the so-called moving layer. Since this method detects information on the sintered bed of the filling material that is actually charged, there is a problem in terms of accuracy.

In contrast to these methods, the method of detecting the filling density using an r-line densitometer detects the v! ! There are no accuracy problems due to material adhesion in the measurement method using a ventilation pipe, and the inventors' investigation results show that γ
Line 'i! The 5-degree meter can fully satisfy the required detection accuracy.

In this way, in the present invention, the blended raw materials are sintered/1'
The packing density of each divided gate after M is charged into the let is detected, and the dividing gate is operated manually or automatically according to the difference in packing density of each gate at that time. Increase or decrease the amount of raw material cut out. As a result, the packing density of the filling material charged into the sintering pallet in the width direction of the sintering pallet becomes an appropriate value. As a result, the ventilation resistance in the width direction of the sintering pallet is optimized, the uneven thermal history during firing in the width direction of the sintering pallet is reduced, and the sintering
The decrease in sintering yield at both ends of the ceret is rejuvenated.

(Example) As shown in FIG. 4, the dividing gate 4 that controls the change in filling in the width direction of the sintered pallet is designed to have a symmetrical structure in the width direction of the sintered pallet. A sintered pallet with a width of 3500 m was divided into 5 pieces: 250 m on both ends and 10 UOm on the center side.

The installation position of the r-line density needle 7 was at the center of each dividing gate 4 in the width direction of the sintered nozzle, and at the center of the increase in thickness in the height direction of the sintered bed.

The results of the sintering yield distribution survey of the cross section of the sintered pallet before and after implementation of the present invention are shown in FIGS. 5(1) and 5(b). Before implementing the present invention, as shown in Figure 5 (a), the sintering yield at both ends of the sintered sheet was markedly reduced; however, by implementing the present invention, as shown in Figure 5 (b), The sintering yield at both ends of the sintered pallet is improved, and the sintering yield at the cross section of the sintered pallet is the same as above. In this way, the amount of material cut out from the dividing gate 4 is controlled so that the packing density of the filling material in the sintering/e-let width direction is appropriate, so that The thermal history has been made uniform, making it possible to improve the sintering yield.

(Effects of the Invention) As described above, according to the present invention, it is possible to increase the sintering yield in the pallet width direction, and therefore the overall sintering yield can also be improved.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1(A) is a sectional view and a front view of an example of a raw material charging part used in the method of the present invention, and FIG. 2 is a sectional view of a dividing gate. Figure 3 is a front view of the dividing gate, Figure 4 is a sectional view of the raw material charging section in an embodiment of the present invention, and Figures 5 (a) and (b) are cross sections of the sintered pallet before and after implementing the present invention. FIG. 3 is a diagram showing a comparison of sintering yield distribution survey results. 1...Charging hopper, 2...Drum fuser, 3
...cutting gate, 4...dividing gate, 5...hydraulic silling, 6...slow pink slate, 7-...-
γ-ray density needle % 8... Signal processing device, 9... Arithmetic processing device, 10... Equal filling in width @ degree difference setting board, 11...
- Control device, 12... Filling raw material. Agent Patent attorney Masamoto Aki Sawa and 1 other name Kishi 2'73 Figure 74 Figure A 5 (A) (After Tekirise yield 1?l'2'l) (B)

Claims (1)

[Claims] (1) In a sintering compound material charging method in which the sinter 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 or more parts in the width direction of the sintering pallet, and The amount of mixed raw material supplied at each divided gate can be adjusted, and the filling density of the filled raw material is detected on the sintered pallet below the drum feeder by a γ-ray densitometer in correspondence with each divided gate, and the γ-ray A sintering machine that adjusts the amount of mixed raw materials supplied to each divided gate so that the filling density distribution of each gate detected by a density meter is equal to the preset filling density distribution in the width direction of the sintering pallet. raw material charging control method.