JPH06330193A - Operation of sintering machine - Google Patents

Abstract

PURPOSE:To stabilize reducing powdered index of a sintered ore and to reduce an operational cost. CONSTITUTION:In the operation method of a sintering machine, in which exhaust blast temp. at each position in the width direction in the interval of the exhaust blast temp. raising position and an ore discharging part is measured and the charging bulk height of the raw material in the ore supplying part is adjusted and controlled by operating the opening degree of the divided gates 5-1-5-5 in the width direction of an ore supplying part based on the exhaust blast measured temp. at each position in the width direction, the aimed exhaust blast temp. at the center part of a pallet is corrected based on the difference between the measured value of the reducing powdered index and the aimed value. Together with this correction, the exhaust blast temp. of both sides at the side walls of the pallet is set at lower than the average exhaust blast temp. in the width direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a sintering machine in a Dwightroid type sintering machine (hereinafter referred to as a DL sintering machine) which can stabilize the reduction powdering index of sintered ore and reduce the operating cost. .

[0002]

2. Description of the Related Art In a DL sintering machine, air is sucked from the upper part of a charged raw material layer toward the lower part thereof, and the coke mixed in the raw material is sequentially burned to cause a sintering reaction between raw material ore particles. And, the melting reaction is promoted, and a massive sinter having a high porosity is obtained. The biggest problem in sinter is 400 ~
This is a reduction pulverization phenomenon in which pulverization occurs when reduced at around 600 ° C. It is said that when the hematite in the sinter ore is reduced to magnetite, volume expansion occurs, so that the sinter ore is pulverized. There is a reduction powdering index (RDI) as an index representing reduction pulverization. This is to raise the temperature of a sinter of 15 to 20 mm to 550 ° C., reduce it with a mixed gas of CO 30% and N ₂ 70% for 30 minutes, cool it down to 90 with a small tumbler.
After rotating 0 times, it is sieved with a 3 mm sieve and expressed by a ratio of 3 mm or less. Factors that affect the reduction powderability include magnetite in sinter ore and basicity of sinter, and it is common to control the amount of coke used to control FeO in sinter. is there.

Further, in the DL sintering machine, when the sintering state of the sintered ore packed bed on the pallet is observed at the end of the ore discharge side,
Part of the pallet on the pallet that has been sufficiently baked in the width direction and part that has not been fully baked (unbaked part)
There is a case where there is a so-called uneven burning phenomenon. When such uneven burning in the width direction occurs, the quality (falling strength, particle size, chemical composition, etc.) of the sintered ore is deteriorated and varies, and the rate of occurrence of returned ore increases. As a result, the production volume of the sintered ore is seriously adversely affected, for example, the production volume is reduced.

As a method of preventing uneven burning in the width direction in the above DL sintering machine, the temperature distribution in the width direction of the pallet in the windbox on the mine ore side is measured and the distribution of the deviation ΔTi from the average temperature of the temperature is calculated. On the other hand, the distribution of the layer thickness of the packed bed in the pallet width direction on the mine side is measured, the distribution of the deviation ΔHi from the average value of the layer thickness is obtained, and the variation width of ΔTi with respect to the variation amount of ΔHi at the corresponding width direction position. And then
A method of controlling the layer thickness distribution in accordance with the target value of the layer thickness in the pallet width direction based on the estimated value (JP-A-3-177787).
Gazette), so that there is no difference in the width direction of the exhaust air temperature measured at each position in the width direction measured between the exhaust air temperature rising position of the sintering machine and the exhaust ore portion, the width of the raw material charging bulk of the ore supply portion. In the operating method of the sintering machine that adjusts the difference in direction, the raw material charging bulkiness of at least the left and right sides and the central part of the mining section is measured, and the bulkiness of both the left and right sides is the distance meter installed on both the left and right sides of the mining section. And the raw material surface, and a method of adjusting the widthwise raw material charging amount so that the bulkiness of the central portion is equal to or more than a preset predetermined value (Japanese Patent Laid-Open No. 3-287728), and exhaust air from the sintering machine. The width difference of the split gate opening in the width direction of the mining section is manipulated so that there is no difference in the width direction of the exhaust air temperature measured at each position in the width direction between the temperature rising position and the discharge section. For operating method of sintering machine to adjust the difference in bulk width of raw material charging in ore Then, a method of operating the width direction difference of the divided gate opening in the width direction so that the average value in the width direction of the absolute value of the opening degree of each divided gate in the width direction becomes close to a predetermined value set in advance (Japanese Patent Laid-Open No. Hei 4- No. 329838) has been proposed.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The methods disclosed in JP-A-787, JP-A-3-287728 and JP-A-4-329838 all control to reduce the temperature difference in the pallet width direction. The wind temperature is not set lower than the average temperature in the width direction,
Further, it is not mentioned that the exhaust air temperature pattern in the width direction affects the reduction pulverization index.

An object of the present invention is to provide a method of operating a sintering machine which can stabilize the reduction powdering index in the DL sintering machine and can reduce the power consumption.

[0007]

[Means for Solving the Problems] The inventors of the present invention have made extensive studies to achieve the above object. As a result, the reduction pulverization index can be controlled by adjusting the exhaust air temperature at the center of the pallet, which has a higher yield than the pallet side wall side, and the exhaust air temperature on both sides of the pallet side wall can be controlled in the width direction. It was clarified that the electric power consumption rate can be reduced by lowering the temperature of the exhaust gas below the average, and the present invention was reached.

That is, the present invention measures the exhaust gas temperature at each position in the width direction between the exhaust gas temperature rising position of the sintering machine and the exhaust ore section, and measures the measured exhaust gas temperature at each position in the width direction. Based on the operating method of the sintering machine, which controls the bulk loading of the raw material charging part by operating the split gate opening in the widthwise direction of the mining part based on the It is a method of operating a sintering machine, which is characterized in that correction is performed based on a difference between a measured value and a target value.

Further, the exhaust air temperature at each position in the width direction is measured between the exhaust air temperature rising position of the sintering machine and the exhaust ore section, and the air supply temperature is supplied based on the measured exhaust air temperature at each position in the width direction. In the operating method of the sintering machine, which controls the bulk height of the raw material charging in the ore feeding section by operating the opening of the split gate in the width direction of the ore section, the target exhaust temperature at the center of the pallet is set as the measured value of the reduction dusting index. A method of operating a sintering machine is characterized in that the temperature is adjusted based on the difference from the target value, and the exhaust air temperature on both sides of the pallet side wall is set lower than the average exhaust air temperature in the width direction.

[0010]

In the present invention, the target exhaust air temperature at the center of the pallet is corrected based on the difference between the measured value and the target value of the reduction pulverization index, so that the reduction pulverization index of the sinter is stabilized. be able to. Also, since the exhaust air temperature on both sides of the pallet side wall is set lower than the average exhaust air temperature in the width direction, firing on both sides of the pallet side wall is delayed, and the amount of shrinkage due to sintering progresses on both sides of the pallet side wall. As a result, air leakage between the side wall of the pallet and the filling layer is reduced, the air volume basic unit of the main exhauster is reduced, and the electric power basic unit can be reduced.

As shown in FIG. 4, except that the exhaust air temperature patterns at the five points in the width direction are flat type, M type, inverted V type, and V type, the flat condition is maintained under other conditions such as raw material conditions. Except for the mold, the temperature was adjusted such that the temperature difference between MAX and MIN was 100 ° C. and fired, and the reduction pulverization index and the electric power consumption rate were examined using an actual machine. The results are shown in Table 1.

[0012]

[Table 1]

As shown in Table 1, regarding the reduction pulverization index, the inverse V type having the highest temperature in the central portion has the lowest value, and conversely the V type has the highest value. That is, the reduction pulverization index can be controlled by adjusting the exhaust air temperature at the center of the pallet, which has a better yield than the side wall of the pallet. The reason for this is that the formation of secondary hematite that is generated in the cooling process and adversely affects the reduction pulverization index is suppressed by increasing the cooling rate by increasing the firing speed, and vice versa if the firing is slowed. Because. Regarding the power consumption rate, the M type is the best, followed by the inverted V type. That is, by lowering the exhaust air temperature on both sides of the pallet side wall than the average exhaust air temperature in the width direction, it is possible to reduce the power consumption rate. The reason for this is that by delaying the firing on both sides of the pallet side wall, the amount of shrinkage due to the progress of sintering is suppressed on both sides of the pallet side wall, the leakage of air between the pallet side wall and the filling layer is reduced, and the unit air volume is reduced. Because it does.

From the above results, the target pattern of the exhaust air temperature in the width direction is set based on, for example, the following equations (1) to (3) and operated to stabilize the reduction powdering index of the sinter. It is possible to reduce the consumption of electricity and to reduce the power consumption rate. Equation (3) is an equation derived from the fact that the total of the target values at each point in the width direction must be zero. Pallet side wall sides (2 points) = - A .......................................... (1) Pallet central portion (1 point) = C + g × {B × (RDI M -RDI A) -C} ………………… (2) Between both sides and the center (2 points) = A- [C + g × {B × (RDI _M −RDI _A ) − C}] / 2 (3) However, A: a set value that lowers the target temperature on both sides of the pallet side than the average in the width direction (for example, 50 ° C.) B: a coefficient that adjusts the target temperature of the central portion of the pallet based on the measurement value of the reduction powdering index (for example, 50 C:%) C: Target temperature of the center of the previous pallet (° C) g: Smoothing gain (-) RDI _M : Measured value of reduction pulverization index (%) RDI _A : Target value of reduction pulverization index (%)

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic diagram showing an example of equipment configuration for carrying out the method of the present invention, and FIG.
FIG. 3 is a schematic plan view of the main part of the sintering machine of FIG. 3, and FIG. 3 is a graph showing changes in the distance from the ignition furnace and the temperature of exhaust air in the sintering machine of FIG. In FIGS. 1 and 2, 1 is a raw material tank, 2 is a mixer for adding and mixing water to a sintering raw material cut out from the raw material tank 1,
3 is a surge hopper for sintering raw material in which water is added and mixed by the mixer 2, 4 is a rotary feeder for cutting out the sintering raw material from the surge hopper 3, and 5-1 to 5-5 are in the width direction of the cutout of the surge hopper 3. Five division gates installed, 6-1 to 6-5 are raw material charging bulkiness meters arranged corresponding to the positions of the division gates 5-1 to 5-5, and 7 is a pallet of cut out sintering raw materials. At the ore chute to be mined on grade 8, the number of rotations of the rotary feeder 4 and the dividing gate 5-
By adjusting the opening degree of 1 to 5-5, the sintering raw material is adjusted so that the measured values of the raw material charging bulk height gauges 6-1 to 6-5 installed at the respective positions in the width direction become the target values. It is cut out and fed via a feed chute 7 onto a grade 8 pallet.

Numeral 9 is a packed bed of the sintering raw material fed on the grade 8 of the pallet, 10 is an ignition furnace for igniting the surface of the packed bed 9, 11 is a wind box provided under the grade 8 of the pallet, The combustion gas is sucked downward by the main exhauster 12 through each wind box 11 and the sintering proceeds. 13 is each wind box 11
A thermocouple for measuring the exhaust air temperature provided at, a combustion front 14 in the packed bed 9, a firing point 15, and the exhaust air temperature is almost constant until the combustion front reaches the grade, as shown in FIG. ,
It shows the transition of the combustion front rising before and after reaching the grade, that is, the firing point. Numerals 16-1 to 16-5 are thermocouples provided at five positions in the width direction directly below the pallet between the firing point 15 and the exhaust ore section (not shown). The exhaust air temperature at each position in the width direction is measured to determine the width. It outputs to the direction temperature control arithmetic unit 17. Further, the width direction temperature control calculation device 17 is input with the measured values of the raw material charging bulk height gauges 6-1 to 6-5.

Reference numeral 18 is a sampler for intermittently collecting a sample from the sintered ore discharged from the sinter and cooled by a cooler (not shown), and 19 is a reduction for measuring the reduction pulverization index of the sample collected by the sampler 18. A dusting index measuring device, 20 is a measurement value RDI _M of the reducing dusting index measured and input by the reducing dusting index measuring device 19 and a target temperature on both sides of the pallet side wall input from a separate manual setting device 21 in the width direction. based set value a lower than average, the target temperature of the pallet central factor B is adjusted based on the measured value of reduction degradation index, smoothing gain g, the target value RDI _a of reduction degradation index, the (1) ~
It is a width direction temperature target pattern calculation device that calculates a target pattern of the exhaust air temperature in the width direction by the expression (3) and outputs it to the width direction temperature control calculation device 17. The width direction temperature control calculation device 17 includes the exhaust air temperature at each position in the width direction input from the thermocouples 16-1 to 16-5, and the raw material charging bulk height meter 6-1 to 6-1.
On the basis of the width direction raw material charging bulkiness input from 6-5 and the target pattern of the width direction exhaust air temperature input from the width direction temperature target pattern calculation device 20, the width direction exhaust air temperature is the target pattern. Each divided gate 5-1 to 5-5
Of the divided gates 5-1 to 5-5 is operated to reach the target opening, and the difference in the bulk height of the raw material charging in the width direction is adjusted.

With the above configuration, the width direction temperature target pattern calculation device 20 inputs the measurement value RDI _M of the reduction dusting index measured and input from the reduction dusting index measuring device 19 and the separate manual setting device 21. A set value A for lowering the target temperature on both sides of the pallet side wall than the average in the width direction, a coefficient B for adjusting the target temperature at the center of the pallet based on the measured value of the reduction pulverization index, a smoothing gain g, a reduction pulverization index Based on the target value RDI _A of (1) to (3)
The target pattern of exhaust temperature in the width direction is calculated by the formula,
It is output to the width direction temperature control calculation device 17. The width direction temperature control calculation device 17 includes the exhaust air temperature at each position in the width direction input from the thermocouples 16-1 to 16-5, and the width direction input from the raw material charging height gauges 6-1 to 6-5. Based on the raw material charging bulkiness and the target pattern of the width direction exhaust air temperature input from the width direction temperature target pattern calculation device 20, each divided gate 5- is set so that the width direction exhaust air temperature becomes the target pattern. The target opening of 1 to 5-5 is calculated, and each divided gate 5-
The opening degree of 1 to 5-5 is operated so as to become the target opening degree, and the widthwise difference of the raw material charging bulkiness is adjusted.

As a result, the reduction pulverization index is stabilized at the target value, and the exhaust air temperature on both sides of the pallet side wall is kept lower than the average exhaust air temperature in the width direction. However, the amount of shrinkage due to the progress of sintering is suppressed on both sides of the pallet side wall side, the air leakage between the pallet side wall and the packed bed 9 is reduced, and the unit air volume of the main exhauster 12 is reduced, and the unit power consumption is reduced. Reduce.

Sintering was carried out after the present invention in which the widthwise exhaust air temperature was controlled to have a target pattern by the above method and before the present invention in which the widthwise exhaust air temperature was controlled to be flat. The variation (standard deviation) of the ore reduction powdering index and the power consumption rate were measured. The results are shown in Table 2. As shown in Table 2, after the present invention was carried out, the standard deviation of the sinter ore reduction powdering index was reduced by 0.4%, and the power consumption rate was reduced by 0.6 Kwh / T.

[0021]

[Table 2]

[0022]

As described above, according to the method of the present invention, it is possible to stabilize the reduction powdering index of the sintered ore in the DL sintering machine and to reduce the power consumption rate. Stable operation of the machine and reduction of operating cost can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of equipment configuration for carrying out the method of the present invention.

FIG. 2 is a schematic plan view of a main part of the sintering machine of FIG.

FIG. 3 is a graph showing a transition of a distance from an ignition furnace and an exhaust air temperature in the sintering machine of FIG.

FIG. 4 is an explanatory diagram of a widthwise exhaust temperature pattern.

[Explanation of symbols]

 1 Raw material tank 2 Mixer 3 Surge hopper 4 Rotary feeder 5-1 to 5-5 Dividing gate 6-1 to 6-5 Raw material charging bulk height meter 7 Mining chute 8 Grade 9 Packed bed 10 Ignition furnace 11 Wind box 12 Main discharge Blower 13, 16-1 to 16-5 Thermocouple 14 Combustion front 15 Burning point 17 Width direction temperature control calculation device 18 Sampler 19 Reduction dusting index measurement device 20 Width direction temperature target pattern calculation device 21 Manual setting device

Claims (2)

[Claims] 1. The exhaust air temperature at each position in the width direction between the rising position of the exhaust air temperature of the sintering machine and the exhaust ore section is measured, and the air temperature is supplied based on the measured exhaust air temperature at each position in the width direction. In the operating method of the sintering machine, which controls the bulk height of the raw material charging in the ore feeding section by operating the opening of the split gate in the width direction of the ore section, the target exhaust temperature at the center of the pallet is set as the measured value of the reduction dusting index. A method for operating a sintering machine, which comprises performing correction based on a difference from a target value. 2. The exhaust gas temperature at each position in the width direction between the exhaust gas temperature rising position of the sintering machine and the exhaust ore section is measured,
In the operating method of the sintering machine, which controls the bulk loading of the raw material in the feed section by operating the split gate opening in the width direction of the feed section based on the measured exhaust air temperature at each position in the width direction, a pallet Correct the target exhaust air temperature in the center based on the difference between the measured reduction dusting index and the target value, and set the exhaust air temperatures on both sides of the pallet side wall to be lower than the average exhaust air temperature in the width direction. A method of operating a sintering machine, characterized by: