JPH02213425A - Method for controlling completing point position of sintering in manufacture of agglomerated ore - Google Patents

Abstract

PURPOSE:To prevent the deterioration of quality of agglomerated ore or loss of production by obtaining completing point of sintering based on noise level value measured with plural noise sensors set at upper part of charged layer and quickly controlling this point position. CONSTITUTION:On the surface of green pellet charged into pallet 1 in a sintering machine, ignition is executed at an ignition furnace 6 at rear part of a drying furnace 5. The air is sucked as passing through this green pellet layer through wind box 5 and duct 4 and the generated combustion zone is progressed downward from the surface layer. By this method, the whole thickness of the green pellet layer is sintered and the obtd. agglomerated ore is discharged from an ore discharging part 10. In manufacture of the above agglomerated ore, the plural noise sensors 7 are set at the upper part of the charged layer in the rear part of the ignition furnace 6 in longitudinal direction of the machine leaving a space. Based on the noise level of explosive sound of the green pellet measured with this, the completing point of the sintering is obtd. with an arithmetic control unit 8. Further, the pallet 1 velocity is controlled through a driving motor 9 for the sintering machine so that this completing point of the sintering comes to the optimum position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for controlling the position of a sintering end point in the production of agglomerated ore, in which the pallet speed is controlled by measuring the popping sound of a green pellet.

[Conventional technology] Agglomerate ore is generally produced as follows.

The return ore of 4mm or less generated during the crushing and sizing process of powdered iron ore, serpentine, etc. and the crushing of agglomerate ore is mixed in a mixer, granulated in a secondary pelletizer, and then in a secondary pelletizer. , Perform secondary granulation to coat the surface of this granulated material with solid fuel such as coke powder, char, and pulverized coal.
Green pellets with a size of 5 to 10 cm are produced, and the green pellets are charged into an endless moving grate type sintering machine and fired. The fired product is crushed to a predetermined size, cooled, and sized to produce agglomerated ore of 4ffi or more.

In the above manufacturing process, when the green pellet is charged into a sintering machine and fired, the sintering end point position control method used in the normal sintering method is most often used. That is, as shown in FIG. 3, a thermometer 3 such as a thermocouple is provided in each wind box 2 provided below the pallet 1, and the temperature of the exhaust gas passing through the wind box 2 is measured with the thermometer 3. Find the wind box with the highest gas temperature from the temperature distribution, and use it as the sintering end point.
The speed of the pallet is controlled so that the sintering end point is at the appropriate position.

Other sintering end point position control methods for normal sintering include:
Japanese Patent Laid-Open No. 147820/1983 discloses a method in which the temperature distribution in the red zone at the bottom of the charged raw material is directly measured using an optical fiber thermometer in a wind box to determine the sintering end point.

[Problem H to be solved by the invention] The conventional sintering end point position control method is to
The end point of sintering cannot be detected until ~30 minutes have elapsed; therefore, even if there are changes in factors that cause variations in sintering speed, such as air permeability, during this time, actions are taken on the pallet speed of the sintering machine. As a result, there is a problem of deterioration of the quality of agglomerate or loss of production.

[Problem and means for solving the problem] This invention aims to solve the above problems.
A plurality of noise sensors are installed at intervals above the charging layer after ignition f and in the machine length direction to measure the noise level, determine the sintering end point based on the noise level value, and determine the sintering end point. This is a method for controlling the position of the sintering end point in the production of agglomerated ore, characterized by controlling the pallet speed so that the is at the optimum position.

[Operation] From the noise level value caused by the bursting sound of green pellets in the combustion zone of the charging layer passing under multiple noise sensors installed near the ignition furnace, a linear attenuation equation for the noise level is determined, and the noise level at the end of sintering is determined. If the distance corresponding to the level value is determined, that distance becomes the position of the sintering end point. By having a calculator perform this calculation, the sintering end point can be detected about 15 to 20 minutes earlier than in the conventional method. Therefore, deterioration of the quality of the agglomerate or loss of production amount during this period can be prevented.

[Example] An example of the present invention will be described below based on the drawings. 1st
The figure is a block diagram for implementing the method of the present invention, and FIG. 2 is a graph for explaining the sintering end point position control method of the present invention.

In FIG. 1, green pellets loaded onto a pallet 1 of a sintering machine are dried in a drying oven 5 that uses high-temperature exhaust gas from the sintering machine, and then ignited on the surface of the pelletized pellet layer in an ignition oven 6. Ru.

On the other hand, in the drying oven 5 and beyond, a main blower (not shown)
17, gas or atmospheric air is sucked downward through the wind box 2 and the main duct 4 through the layer of green pellets loaded onto the pallet 1. The combustion zone formed on the surface of the green pellet layer advances downward as the pallet moves, and the entire height of the green pellet layer is sintered before the sintering machine discharge section 10, and the combustion zone continues from the ore discharge section 10. be discharged. The discharged sintered body is sent to a crushing and sizing process. In this process, among the raw pellets in the combustion zone, those that contain iron ore, which is prone to thermal cracking, cause bursting due to thermal cracking of the iron ore and vaporization of internal moisture, and at that time, a bursting sound is produced. When the noise level of this plosive sound was measured on the green pellet layer, it was found that it attenuated linearly as the combustion zone progressed downward through the green pellet layer. above the charge layer of and
Multiple noise sensors 7 in the direction of the aircraft (1, 2° 3.4)
are provided at equal intervals, for example, at 2 m intervals. The noise level signals measured by the plurality of noise sensors 7 are sent to the arithmetic controller 8.
sent to. The arithmetic controller 8 determines a noise level attenuation linear equation from the transmitted noise level value, and determines the intersection point of the sintering end point with the straight line of the noise level value - No. That is,
In Figure 2, the obtained noise level attenuation linear equation is B
If so, the distance coordinate D4 of the intersection of the sintering end point with the straight line with the noise level value=No is determined. Then, it is confirmed where D4 is at the zeroth order representing the distance from the rear end of the ignition furnace at the sintering end point at this time, and where D4 is in the set optimum range DI to D2. In this case, the optimal range is ~D2
Because it is located closer to the ore discharge area (sintering speed is slower),
When the determined noise level attenuation linear equation that provides a signal to reduce the pallet speed by a predetermined amount is A, the distance coordinate of the sintering end point is D5. Since D5 is located within the optimum range, ~D2, no pallet speed increase/decrease signal is issued.When the obtained noise level attenuation linear equation is A, the distance coordinate of the sintering end point is D3.

Since D3 is located in the optimum range, closer to the ignition furnace than Dl to D2 (sintering speed is faster), a signal is issued to increase the pallet speed by a predetermined amount.The increase or decrease in pallet speed is determined by the calculated sintering speed. Find and determine the pallet speed at which the end point is within i & trace range and ~Dλ. The arithmetic controller 8 sends the increase in pallet speed 1111i,t determined in this manner to the drive motor 9 of the sintering machine. The drive motor 9 is driven by the received signal.
Barre, increase or decrease the distance. Therefore, the sintering end point is always controlled to be within the optimum range.

The noise sensor is preferably installed within a range of 5 to 10 m from the rear end of the ignition furnace. By setting it within this range, it is possible to detect the end point <+i> about 15 to 20 minutes earlier than in the conventional method.

[Effects of the Invention] Since the present invention determines the sintering end point using multiple noise sensors installed at the rear of the ignition furnace and controls the pallet speed, the pallet speed can be controlled approximately 15 to 20 minutes faster than the conventional method. can be controlled. Therefore, the effect of eliminating deterioration in the quality of agglomerated ore or loss of production during this period, which conventionally occurred, can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for implementing the method of the present invention, and FIG. 2 is a graph diagram for explaining the sintering end point position control method of the present invention.
FIG. 3 is a diagram illustrating a conventional sintering end point position control method. 1... Pallet, 5... Drying oven, 6... Ignition oven,
7... Noise sensor, 8... Arithmetic controller, 9...
Drive motor, 10... ore discharge section.

Claims (1)

[Claims] A plurality of noise sensors are installed at intervals above the charging layer after the ignition furnace and in the machine length direction to measure the noise level, determine the sintering end point based on the noise level value, and determine the sintering end point. 1. A method for controlling the position of a sintering end point in agglomerate ore production, the method comprising: controlling the pallet speed so that the sintering end point is at an optimal position.