JPH08170880A - Baking method for sintered ore - Google Patents

Abstract

PURPOSE: To provide a baking method for sintered ore by which the temperature of sintered ore is distributed on a required pattern, independent of the distribution of baking-temperature in a sintering process. CONSTITUTION: Above palletes 4 on the discharge side of ores, a plurality of temperature detectors 8, which are arranged being almost perpendicular to the carrying direction of the palletes 4 at regular intervals, are provided in two lines so as to mutually make a pair in the carrying direction thereof, and values of detected temperature are inputted to a computer 10. A detected temperature Te by the temperature detector 8 at the discharge side is compared with a detected temperature Ts by the temperature detector 8 at the supply side, by the computer 10. In the case of Ts<Te, a correlation between a detected temperature and a bulk height is determined to be negative. In the case of Ts>=Te, the correlation between them is determined to be positive. On the other hand, a control parameter Ki in the case where the correlation between them is positive or negative is respectively operated on the basis of a state vector in a sintering process, by the computer 10, and the control parameter Ki suitable therefor is selected on the basis of a result determined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for firing sinter in a Dwightroid sinter.

[0002]

2. Description of the Related Art In ironworks, powders such as undersize powder generated in the pretreatment stage of blast furnace charging raw material, dust collected in blast furnace gas, and powdered ore supplied as raw material ore are agglomerated. The sintering method is widely used for the purpose of treating and regenerating it as an artificial raw material. In particular, the sintering method using a Dwightroid-type sintering machine enables mass production and is excellent in quality. It is widely practiced as a method of obtaining ore.

The Dwightroid-type sintering machine arranges a plurality of endlessly connected pallets so as to be movable along a predetermined transfer path, supplies raw materials onto the pallet on one side of the transfer path, and pallets the pallet. While transporting by moving
The coke mixed in the raw material is ignited in an ignition furnace configured in the middle of this transport path, and combustion is progressed by continuous ventilation to the lower side of the pallet to burn the raw material being transported, which is then transported. On the other side of the route, it is taken out as sinter. The taken out sinter is cooled, crushed and sieved to obtain an appropriate particle size, and used as a blast furnace charging raw material.

In the operation of such a Dwightroid-type sintering machine, when firing unevenness occurs, which is a phenomenon in which the firing degree of the sintered ore on the take-out side varies in the width direction of the pallet, firing failure occurs. Since there is a problem that the yield rate decreases due to the increase in the rate of occurrence of returned ore, it is an important issue to make the temperature distribution in the width direction of the pallet a required pattern.

In order to solve this problem, Japanese Patent Laid-Open No. 3-1777
A method as described in Japanese Patent No. 87 has been proposed.
This is a negative correlation between the temperature distribution in the pallet width direction on the sinter extraction side (exhaust ore side) and the bulk material distribution in the pallet width direction on the raw material supply side (feeding side). Based on the knowledge that there is such a problem, the bulkiness is adjusted as follows so that the temperature distribution in the pallet width direction on the mine ore side has a required pattern.

The temperature distribution in the pallet width direction on the mine ore side is measured, and the distribution of the deviation ΔTi from the average temperature of the pallet width is obtained, while the distribution of the bulkiness of the raw material in the pallet width direction on the mine side is measured. The distribution of the deviation ΔHi from the average value of the bulkiness is obtained, the change width of ΔTi with respect to the change amount of ΔHi at the corresponding widthwise position is estimated, and the estimated value and a regression line of ΔHi and ΔTi having a negative correlation The height setting value Hisv for each width direction is calculated by the following equation (6) on the basis of the inclination Ki of, and the height is adjusted so as to be the calculated Hisv. Hisv = bar Hi-ΔTi / Ki (6)

[0007]

The present inventor has found that there is the following correlation between the bulkiness of the raw material and the temperature on the mine ore side. FIG. 3 is a graph showing a temperature distribution directly below the pallet from the ore supply side to the ore discharge side in the Dwightroid type sintering machine. As the firing of the raw material progresses from the upper part to the lower part, as shown in FIG. 3, the raw material temperature gradually rises from the feed ore side to the mine ore side, and after reaching the maximum temperature point T _T , the temperature decreases and the sintered ore becomes Taken out. At this time, if the bulkiness of the raw material on the mine side is increased, the maximum temperature point T _T moves to the mine side along with it.

Then, the maximum temperature point T _T is moved to examine the correlation between the change in the temperature distribution in the pallet width direction on the discharge side and the change in the bulkiness distribution of the raw material in the pallet width direction on the supply side. However, there is a negative correlation when the maximum temperature point T _T is on the feed side from the temperature measurement point, while a positive correlation is found when the maximum temperature point T _T is on the discharge side from the temperature measurement point. I have a relationship.

In the conventional method, it has been found that there is a negative correlation between the temperature distribution in the pallet width direction on the mine ore side and the distribution of the bulkiness of the raw material in the pallet width direction on the mine side. Based on the above, the control parameter Ki is determined, but depending on the conditions, a positive correlation may be established as described above, and in that case, the temperature distribution on the mine ore side cannot be formed into the required pattern. There was a problem.

The present invention has been made in view of the above circumstances, and its object is to select appropriate control parameters based on the temperatures detected by temperature detectors arranged in a plurality of rows in the pallet transport direction. Accordingly, it is an object of the present invention to provide a method for firing a sintered ore that can make the temperature distribution of the sintered ore on the effluent side into a required pattern regardless of the state of the firing temperature distribution in the sintering process.

[0011]

A method of firing a sintered ore according to a first aspect of the present invention is a method of firing a sintered ore in which a raw material is supplied to one side of a circulation area of a plurality of pallets connected in series and the raw material is fired. In the Dwightroid-type sintering machine that discharges the pallets from the other side, the pallet is conveyed in the conveying direction so that the temperature detected by a plurality of temperature detectors arranged in the direction intersecting the conveying direction of the pallets on the discharging side becomes a predetermined pattern. By controlling the operation amount of the opening of multiple supply amount control gates arranged in the intersecting direction, the bulkiness of the raw material detected by the level meter arranged corresponding to each supply amount control gate is adjusted and sintered. In the method of firing ore, the plurality of temperature detectors are arranged in two rows so as to form a pair in the conveying direction of the pallet, and a change in the temperature detected by each temperature detector in one row and detection by each level meter Based on the change in bulkiness and the change in the manipulated variable The control parameters for controlling the manipulated variable are calculated for the case where the maximum temperature in the conveying direction of the pallet of the raw material is upstream and downstream of each temperature detector in the one row, respectively, and Is compared with each other, and one of the calculated control parameters is selected based on the comparison result.

The firing method of the sintered ore according to the second invention is the first
In the invention, the control parameter is a parameter whose positive and negative values are different when the maximum temperature in the conveying direction of the raw material pallet is upstream and downstream of each temperature detector of the one row, and both parameters are used. It is characterized in that the relation between the detected temperature and the bulkiness is calculated so as to be stable in a closed loop.

[0013]

In the sinter ore calcination method of the present invention, if the maximum temperature of the raw material pallet in the conveying direction is upstream from the plurality of temperature detectors arranged in the direction intersecting the pallet conveying direction, Since the detected temperature and the bulkiness have a positive correlation and the downstream side has a negative correlation, the control parameters for controlling the operation amount of the opening of the supply amount adjusting gate are set to the above-mentioned Based on the change in the temperature detected by the temperature detector, the change in the bulkiness detected by each level meter, and the change in the operation amount of the opening of the supply amount adjusting gate, the maximum temperature is on the upstream side and the downstream side. Parameters having different positive and negative values are used, and the parameters are calculated so that the relationship between the detected temperature and the bulkiness is closed-loop stable for both parameters.

Further, a plurality of temperature detectors are arranged in two rows so as to form a pair in the conveying direction of the pallet, and a temperature T _e detected by the temperature detector arranged on the discharge side and a temperature detection arranged on the supply side. When the temperature T _s of the detector is compared with T _s <T _e , the highest temperature is downstream of the temperature detector of the controlled column, and there is a negative correlation between the detected temperature and the bulkiness. On the contrary, when T _s ≧ T _e , it is determined that there is a positive correlation between the detected temperature and the bulkiness. Then, based on this judgment, the corresponding control parameter is selected from the control parameters. As a result, the temperature distribution of the sinter ore on the discharge ore side can be made into a predetermined pattern regardless of the state of the sinter process.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments thereof. FIG. 1 is a schematic perspective view showing a sintering machine for applying the present invention, in which 1 is a feed hopper,
Reference numeral 2 is a drum feeder for supplying raw materials, 3 is a main gate whose opening is set according to the production amount, and 4 is a pallet endlessly arranged on the strand. The pallet 4 is conveyed in the arrow direction, and the drum feeder 2 is arranged in a direction substantially orthogonal to the conveying direction of the pallet 4. At a position facing the main gate 3 of the drum feeder 2, a plurality of adjusting gates 5, 5, ... For adjusting the amount of ore supplied from the main gate 3 are provided in a direction substantially orthogonal to the conveying direction of the pallet 4. , Are individually operated by power cylinders 6, 6, ..., The opening of each of the adjustment gates 5, 5, ... Is given to the computer 10.

In the vicinity of the drum feeder 2, ultrasonic level meters 7, 7, ... Which detect the bulkiness of the raw material M supplied on the pallet 4 are arranged, and the ultrasonic level meters 7, 7,
The detected value of ... Is given to the computer 10. Pallet 4
The raw material M supplied above is conveyed in the direction of the arrow along with the movement of the pallet 4, is ignited by the coke mixed in the raw material M in an ignition furnace (not shown), and continuously ventilates the lower side of the pallet 4. The raw material M being conveyed is burned by the above, and is burned, and is discharged as a sintered ore H. Below the pallet 4 on the mine ore side, a plurality of temperature detectors 8 arranged at a predetermined distance in a direction substantially orthogonal to the conveying direction of the pallet 4,
Are provided so as to form a pair in the conveying direction of the pallet 4, and the temperatures detected by the temperature detectors 8, 8, ... Are given to the computer 10.

FIG. 2 is a block diagram showing a control system of the sintering machine shown in FIG. The computer controls the opening of the adjusting gate so that the manipulated variable u is obtained, and takes in the bulkiness of the raw material supplied from each adjusting gate as the input matrix 11 of the sintering process. The supplied raw material is ignited and ventilated, (zI-A)
The temperature immediately below the pallet changes according to the sintering process 12 represented by ^-1 . Where z is the delay operator, I is the identity matrix, and A is the system matrix of the sintering process. The change in the sintering process 12 appears as a change in the state vector x, and the detected temperature immediately below the pallet of the sintered ore sintered under the state vector is captured as the output matrix 13 of the sintering process.

Also, the state vector x is sent to the selection logic 14.
Selection logic 14, the selection logic 14
Based on the cutle x,
Detection temperature T_eAnd the temperature detected by the temperature detectors located on the mining side
Degree T_sCompare with_s<T _eIf the ingredients are
The maximum temperature in the transport direction of the tray is on the mine side from the temperature detector.
Therefore, it is judged that the detected temperature and the bulkiness have a negative correlation,
Conversely, T_s≧ T_eIf the maximum temperature is
On the supply side of the vessel, the detected temperature and bulkiness have a positive correlation
It is determined that On the other hand, based on the state vector x,
When there is a positive correlation between the detected temperature and bulkiness, and
If there is a negative correlation, the control parameters 15
Has been calculated, and the selection logic 14
Based on that, the appropriate control parameter 15 is selected. Soshi
Selected control parameters 15 and predetermined controls
The operation amount u is calculated according to the rule, and the calculated operation amount u is obtained.
Adjust the opening of the adjustment gate.

The control parameters described above are calculated as follows. In each control cycle, the difference between the temperature detected by the temperature detector and the previously detected temperature is x ₁ , the difference between the bulkiness and the previous bulkiness is x ₂ , the difference between the operation amount of the adjustment gate opening and the previous operation amount. Is u, x ₁ and x ₂ are
It is represented by the formula and the formula (2). x ₁ (n + 1) = a ₁ x ₁ (n) −a ₂ x ₂ (n) (1) x ₂ (n + 1) = a ₃ x ₂ (n) + bu (n) (2) where a ₁ : Real number 0 <a ₁ <1 a ₂ : Real number whose positive and negative values are different depending on conditions a ₃ : 0 <a ₃ <1 real number b: Real number n: Control cycle

Here, considering an expansion system including the integral elements of the equations (1) and (2), both equations are expressed by the following equation (3). x (n + 1) = Ax (n) + Bu (n) (3) A: System matrix of the sintering process B: Input matrix of the sintering process x: State vector of the sintering process Then, in the formula (3), u ( Substituting (n) = − Kix (n) results in the following expression (4), and the control parameter Ki that makes the expression (4) stable in the closed loop is calculated. x (n + 1) = (A-BKi) x (n) (4)

The control parameter K calculated in this way
Controlling the bulky by adjusting the opening degree of the adjusting gate at i, for example, when the Ki are those calculated by a _2> 0, while the state of the sintering process is a _2> 0 is, (A -BK
The absolute values of the eigenvalues of i) are all selected to be smaller than 1, and the closed loop is stable, but the state of the sintering process is a ₂
When <0, the absolute value of the eigenvalue of (A-BKi) may be greater than 1, and closed-loop stability is not achieved.
Therefore, when the state of the sintering process becomes a ₂ <0,
Closed loop stability can be achieved by selecting the control parameter Ki calculated with a ₂ > 0.

The control parameters Ki are, for example, the detected temperatures x _T1 , x _T2 , x _T3 , x _T4 , x _T5 and their deviations x _T6 , x.
_{T7, x T8, x T9,} x T10 and on the basis of the control parameter Ki, the operation amount of five regulatory gate _{U 1, U 2, U 3} ,
When the control law according to the following equation (5) for calculating U ₄ and U ₅ is used, 2 ⁵ = 32 types are prepared.

[0023]

[Equation 1]

Next, the result of the comparison test will be described. 4 and 5 are graphs showing the temperature distribution of the front cross section of the sinter, FIG. 4 shows the case where the method according to the present invention is applied, and FIG. 5 shows the case where the conventional method is applied. . In the comparative test, a sintering machine equipped with five control gates was used, and the temperature pattern in the width direction of the sinter was found to have the lowest temperature at both ends, the highest temperature next to it, and the middle temperature between them. I went to

As a result, in the conventional method, as shown in FIG. 5, the temperature at the center of the sintered ore was the lowest and the temperature at one end was the highest. On the other hand, when the method according to the present invention was applied, the required temperature pattern was obtained as shown in FIG.

[0026]

As described in detail above, in the method of firing a sintered ore according to the present invention, regardless of the state of the sintering process,
The present invention has excellent effects such that the temperature in the width direction of the sinter ore can be made into a desired pattern, the occurrence rate of return ore is reduced, and the yield is improved.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a sintering machine to which the present invention is applied.

FIG. 2 is a block diagram showing a control system of the sintering machine shown in FIG.

FIG. 3 is a graph showing a temperature distribution directly below a pallet from a mine supply side to a mine discharge side in a Dwightroid type sintering machine.

FIG. 4 is a graph showing a temperature distribution of a front cross section of a sinter.

FIG. 5 is a graph showing a temperature distribution of a front cross section of a sinter.

[Explanation of symbols]

 1 Mining hopper 2 Drum feeder 3 Main gate 4 Pallet 5 Control gate 8 Temperature detector 10 Computer

Claims (2)

[Claims] 1. A discharge side of a Dwightroid-type sintering machine in which a raw material is supplied to one side of a circulation area of a plurality of pallets connected in series and the sintered ore obtained by firing the pallet is discharged from the other side. Manipulation of the opening of multiple supply amount adjustment gates arranged in the direction intersecting the pallet conveying direction so that the temperature detected by the temperature detectors arranged in the direction intersecting the pallet conveying direction has a predetermined pattern. In the method of controlling the amount, adjusting the bulkiness of the raw material detected by the level meter arranged corresponding to each supply amount control gate, and firing the sinter, the temperature detectors of the plurality of temperature detectors Two rows are arranged so as to form a pair in the transport direction, and the operation is performed based on a change in the temperature detected by each temperature detector in one row, a change in the bulkiness detected by each level meter, and a change in the operation amount. Control parameters to control the quantity, The maximum temperature in the conveying direction of the pallets of materials is calculated respectively for the case of being upstream and the case of downstream of the temperature detectors in the one row, and the detected temperatures of the paired temperature detectors are compared. A method for firing a sintered ore, comprising selecting one of the calculated control parameters based on a comparison result. 2. The control parameter is a parameter whose positive and negative values are different when the maximum temperature of the raw material pallet in the conveying direction is upstream and downstream of each temperature detector of the one row, and both are used. The method for calcination of sinter according to claim 1, wherein the parameter is calculated so that the relationship between the detected temperature and the bulkiness is closed loop stable.