JP3297796B2 - Operating method of sintering machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation method for efficiently producing quality-stable sintered ore using a Dwyroid type (hereinafter referred to as "DL type") sintering machine. It is.

[0002]

2. Description of the Related Art In an on-strand cooling type DL sintering machine, 400-60
While supplying the blended raw material with a layer thickness of about 0 mm and igniting from the surface side, sucking air from the upper part to the lower part of the blended raw material layer, while sequentially burning the coke mixed in the blended raw material, The sintering reaction and the melting reaction between the ore particles of the compounding raw material are promoted, and the mixture is fired and cooled to produce a massive sintered ore having a high porosity. In the production of sintered ore using this DL-type sintering machine, uniform firing in the width direction of the pallet is an important point in improving productivity, stabilizing quality and improving energy intensity.

As a method for achieving uniform firing in the width direction of the pallet of the DL-type sintering machine, the sintering point and the temperature gradient are determined for each width direction based on the transition of the exhaust gas temperature of each wind box measured for each width direction according to the movement of the compounding material. After the detection, for each of the width directions, the value of the sintering point and the value obtained by multiplying the temperature gradient by a predetermined coefficient are added, and the difference between the added values is reduced so that the difference between the added values is reduced. A method of adjusting the difference in the width direction (Japanese Patent Application Laid-Open No. 63-210245). A measuring means is provided for each divided block by the gate, and a relationship between the deviation of the red hot layer and the shape of the charging line in the feed section is obtained off-line. Of the red hot layer And a method of deviation is controlled by the split gate the instrumentation incoming shape in Kyuko side so that the zero-state (JP-A-1-191751) have been proposed.

[0004]

In the uniform firing in the pallet width direction of the DL type sintering machine, the compounding material hopper 1
4 is provided at the lower part of the pallet, and when the raw material supply state is variously changed as shown in FIG. 5 by operating the divided gate 2, the vicinity of the firing front reaching the great bar in the pallet In the wind box (# 19W in FIG. 6)
In the case where the pattern in the width direction of the exhaust gas temperature (indicated by the temperature directly below B) is an inverted V type (indicated by ● in FIG. 6), as shown in FIG. Done (Fig. 6
, The best is known. In addition,
Reference numeral 3 in FIG. 4 indicates a roll feeder.

This is apparent from a comparison between the case of the flat heat pattern shown in FIG. 7 and the case of the inverted V-shaped heat pattern shown in FIG. A gap is formed between the side wall of the pallet 4 and the sintered ore layer 5 as a product due to the compaction of the sintered ore as it progresses, so that only the air flow on both sides of the sintered ore layer 5 with low airflow resistance increases, and the central part is increased. The glowing part 6 will remain in the area. Therefore, as shown in FIG. 9, O ₂ in the exhaust gas
The concentration increases, the heat exchange property between the sintered ore layer 5 as a product and the exhaust gas deteriorates, and the steam recovery rate decreases and the power consumption decreases. Conversely, in the case of the inverted V-shaped heat pattern, the red-hot portion 6 becomes uniform, the quality of the sintered ore layer 5 is improved, and the unit energy consumption can be improved. 7 and 8, reference numeral 7 denotes a great bar, and reference numeral 8 denotes a wind box.

For this reason, Japanese Patent Application Laid-Open No. 63-2102 described above
No. 45 or Japanese Patent Application Laid-Open No. 1-191751, based on the above-mentioned knowledge, the charging state of the compounding material into the pallet is determined by using a dividing gate provided at the lower part of the compounding material hopper. Although the control is performed, there is a problem that the opening degree of the division gate must be adjusted each time due to the occurrence of disturbance such as adhesion of the compounding material to the division gate or biting of a lump. This is due to the fact that the blended raw materials have moisture and that the raw material particle sizes vary.

Japanese Patent Application Laid-Open No. Hei 7-268496 describes that the floor bedding is laid so that the entire central portion in the pallet width direction is thicker than both sides.
According to the method described in JP-A-268496, productivity of sinter is deteriorated because the amount of bedrock used is large, and a large number of small cracks are not uniformly generated because the ore is flat in the width direction. In addition, there is a problem that a single initial crack is promoted starting from the starting point, and a large crack is generated only in the central portion in the pallet width direction, so that uniform firing cannot be performed.

[0008] The present invention has been made in view of the above-described conventional problems, and is not affected by the variation in the moisture and the particle size of the compounding raw materials, and the firing front near the reaching the great bar in the pallet. An object of the present invention is to provide a method of operating a sintering machine capable of improving the quality of sinter and achieving an improvement in energy consumption by controlling the pattern in the width direction of the exhaust gas temperature in a wind box in an inverse V-shape. I have.

[0009]

In order to achieve the above-mentioned object, the present invention provides a method of forming a bedding ore laid on the bottom of a pallet before supplying a compounding material, by forming a predetermined range of a predetermined range in a pallet width direction and a predetermined unevenness. I am trying to be. By doing so, the air permeability in the pallet width direction becomes uniform, and the exhaust gas temperature in the wind box width direction near the point where the combustion front reaches the great bar in the pallet becomes an optimal heat pattern.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have conducted various experiments and studies in order to achieve the above object. As a result, the bedding laid on the bottom of the pallet in order to prevent falling from the Great Bar is to recover and use part of the sinter that has become a product, and contains almost no water. It is easy to control because it is not sized and uniform in particle size, so it is easy to control, there is no disturbance such as sticking to the cutout gate and biting of lump, and control of the heat pattern in the pallet width direction Is easy, and by adding irregularities to the thickness of the bedding, the air permeability of the convex portion is improved as compared to the concave portion, and therefore, cracks from this portion are likely to occur, Small cracks occur in the pallet width direction by the number of protrusions. The width of the cracks is due to the shrinkage of the blended raw materials. The larger the width of the pallet, the larger the width of the pallets. The larger the number of cracks, the smaller the number of cracks per crack. The present invention has been made.

That is, the operation method of the sintering machine of the present invention is as follows.
A sintering machine that supplies compounded raw materials from a supply unit on a pallet with bedding ore at the bottom, ignites the compounded raw material from the front side, and fires the pallet downwards as the pallet moves. In the operation method, the bedding ore laid on the bottom of the pallet before the supply of the blended raw material is adjusted so that the exhaust gas temperature in the width direction of the wind box near the point where the combustion front reaches the great bar in the pallet has an optimal heat pattern. In the pallet width direction, the central portion of the pallet except for 10 to 30% of the pallet has an uneven shape with a height of the convex portion of 20 to 100 mm, a thickness of the concave portion of 20 to 100 mm, and a pitch of 200 to 400 mm. It was done.

In the method of operating a sintering machine according to the present invention, only the central portion except for 10 to 30% of both sides of the pallet is made uneven so that the side portion is ventilated to prevent air leakage from the pallet side plate portion due to compaction. This is for the purpose of suppressing the air flow and improving the ventilation at the center. Further, in the operating method of the sintering machine of the present invention, the height of the uneven projections is set to 20 to 100 mm. If the height of the projections is less than 20 mm, the effect of thickening the bedding is not exhibited. Because. In addition, the height of the projection is 10
If the thickness exceeds 0 mm, the local ventilation is too high, which causes uneven burning.

Further, in the method for operating a sintering machine of the present invention, the reason why the thickness of the concavo-convex recess is set to 20 to 100 mm is that if the thickness of the concavity is less than 20 mm, the bedding ore is removed from the gap between the great bars or the like. This is because the grain size is restricted and cannot be used as bedding ore. When the thickness of the recess is 10
This is because if it exceeds 0 mm, the air permeability becomes too high, and unevenness between the concave portion and the convex portion occurs.

In the method for operating a sintering machine of the present invention, the uneven pitch is set to 200 to 400 mm.
If the pitch is less than 200 mm, the difference between the ventilation at the central portion and the ventilation at the side portions is too large, which leads to deterioration of the quality. If the pitch exceeds 400 mm, the ventilation at the central portion is insufficiently improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for operating a sintering machine according to the present invention will now be described with reference to FIG.
A description will be given based on one embodiment shown in FIG. FIG. 1 is a schematic overall view of a DL type sintering machine to which a method for operating a sintering machine according to the present invention is applied, and FIG. Explanatory drawing of the cutout gate,
FIG. 3 is an explanatory view of the bedrock mined at the bottom of the pallet by the cutting gate of FIG.

1 to 3, reference numeral 11 denotes a pallet of a DL-type sintering machine, 12 denotes a bedding ore hopper, 13 denotes a compounding material hopper, and 14 denotes a roll feeder provided below the compounding material hopper 13. First, the bedding ore 15 is supplied from the bedding ore hopper 12, and the blended raw material 16 is supplied on the bedding ore 15 from the blended raw material hopper 13 by the roll feeder 14 to form a blended raw material layer.

After the blended material layer formed on the pallet 11 is ignited on its surface by an ignition furnace 17, as the pallet 11 advances, each wind box 1
8, air is sucked from the upper part to the lower part through the suction pipe 20 by the main exhaust fan 19, and while the coke mixed in the blended raw material 16 is sequentially burned, the combustion reaction between the raw material ore particles and The melting reaction is accelerated.

The fired product sintered layer is circulated from the upper part to the lower part of each of the wind boxes 21a, 21b in the cooling zone by the first circulating fan 22a and the second circulating fan 22b via the suction pipes 23a, 23b. After being cooled by exchanging heat with the generated hot air, the crusher 2
After being crushed in 4 and cooled by a simple cooler, it is transported to the next step (not shown).

In FIG. 1, reference numeral 25 denotes an electric precipitator disposed upstream of the main exhaust fan 19, 26 denotes a chimney, and 27a and 27b.
Denotes a first boiler and a second boiler arranged upstream of the first circulation fan 22a and the second circulation fan 22b; 28, a circulation hood covering a cooling zone; 29, a camera for photographing an ore discharging portion; Is an electric dust collector, and 31 is a chimney.

In the present invention, a plurality of exhaust air thermometers are installed in the width direction of the pallet 11 in the wind box 21a at the end of the cooling zone on the feeder side, based on the measured values of these exhaust air thermometers. Therefore, the optimal temperature distribution in the pallet width direction, that is, the pattern in the width direction of the exhaust gas temperature in the wind box near the calcination front reaching the great bar 11a in the pallet 11 is, for example, an inverted V-shape. The cutting gate 33 of the bedding hopper 12 is shown in FIG.
The bedding 15 laid on the bottom of the pallet 11 is processed as shown in FIG. Has a thickness of 50mm and a pitch of 250mm
To form a continuous irregular shape.

By laying the bedding ore 15 in the above-described shape, a small compaction crack can be generated in the entire area of the sintered ore layer, the air permeability in the width direction of the pallet 11 is made uniform, and the combustion front is reduced. The exhaust gas temperature in the width direction of the wind box near the great bar in the pallet 11 becomes the optimal heat pattern, and the air leakage due to the tightening near the side wall of the pallet 11 is suppressed, enabling uniform firing in the width direction. Becomes

Next, the results of experiments performed to confirm the effects of the present invention will be described. [Experiment 1] Bedding with an average particle diameter of 10 mm, hot sieving sieve: 7.5% by weight, sintered powder: 17.7% by weight, lobe river: 11.5% by weight, Yandikina: 23. 3
% By weight, Asoman: 14.0% by weight, miscellaneous iron source: 3.0% by weight, Riodose: 17.0% by weight, Karajas: 6.0
Lime: 11.5% by weight, coke:
A blending material of 3.00% by weight was supplied onto a pallet having a width of 3660 mm to form a blending material layer having a thickness of 500 mm, and the pallet was moved at a speed of 2.8 m / min to fire the blending material. .

Based on the measurement results of five thermocouples provided in the width direction of the pallet in the wind box at the beginning of the cooling zone, the exhaust gas temperature distribution in the width direction of the wind box at the beginning of the cooling zone is inverted V-shaped. The bedding ore supply condition is processed by processing the bedding ore mining gate so that the target temperature becomes the target temperature, and the central portion of the pallet except for 800 mm (22%) on both sides of the pallet has the height of the convex portion in the pallet width direction. One month for each of the method of the present invention in which the thickness of the concave portion is 50 mm, the pitch of the concave portion is 50 mm, and the pitch is 200 mm, and the conventional method in which the layer thickness of the compounding material is cut out and the opening of the gate is adjusted and controlled. The average value of the temperature distribution of the exhaust gas in the width direction in the wind box at the beginning of the cooling zone and the average value of the temperature distribution of the cross section of the sinter of the exhaust part were measured, and the deviation from the target value was determined. The results are shown in Table 1 below.

[0024]

[Table 1]

As is clear from Table 1, when the method of the present invention is carried out, the temperature deviation from the target temperature at the beginning of the cooling zone is 1.9 ° C., which is extremely higher than 16.6 ° C. in the case of carrying out the conventional method. In addition, the temperature deviation of the cross section of the product sintered ore in the mining part with respect to the target temperature is also reduced to 3.6 ° C. from 8.0 ° C. when the conventional method is performed.

[Experiment 2] The same bedding ore and the blended raw material as in Experiment 1 were supplied onto a pallet to form a blended raw material layer having a thickness of 500 mm, and the pallet was moved at a speed of 2.8 m / min. The sintering raw material was fired.

Then, based on the measurement results of five thermocouples provided in the width direction of the pallet in the wind box at the beginning of the cooling zone, the exhaust gas temperature distribution in the width direction of the wind box in the wind box at the beginning of the cooling zone is inverted V-shaped. The bedding ore supply condition is processed by processing the bedding ore mining gate so that the target temperature becomes the target temperature, and the central portion of the pallet except for 800 mm (22%) on both sides of the pallet has the height of the convex portion in the pallet width direction. The method of the present invention in which the thickness is 50 mm, the thickness of the concave portion is 50 mm, and the pitch is 200 mm, and the method of the present invention is adjusted so that the thickness of the side wall of the pallet is 50 mm and the thickness of the center of the pallet is 80 mm. The method described in 7-268496 was carried out.

Then, when the variation in the rotational strength and the reduction powder index of the produced sinter was determined, it was found in Japanese Patent Application Laid-Open No. 7-268.
No. 496, the rotational strength TI is 1.0%, and the reduced powder index RDI is 2.0%.
However, in the sintered ore produced by the method of the present invention, the rotational strength TI was 0.7%, and the reduction powder index RDI was 1.5%. In addition, the production yield is also disclosed in
No. 68496, a 0.7% improvement over the sinter produced by the method described in US Pat.

[0029]

As described above, according to the method for operating a sintered ore of the present invention, it is possible to suppress the air leakage caused by the compaction of the pallet side without increasing the use of the bedding ores more than necessary. The air permeability in the pallet width direction becomes uniform, and the exhaust gas temperature in the wind box width direction near the point where the combustion front reaches the great bar in the pallet becomes an optimal heat pattern. Therefore, the cross-sectional temperature of the product in the mining section can be made uniform, the quality of the sintered ore can be improved, and the yield can be improved.

[Brief description of the drawings]

FIG. 1 shows a DL to which a method for operating a sintering machine according to the present invention is applied.
1 is a schematic overall view of a sintering machine.

FIG. 2 is an explanatory view of a bevel ore cut-out gate used for carrying out a method of operating a sintering machine according to the present invention.

FIG. 3 is an explanatory view of the bedding ore mined at the bottom of the pallet by the cutting gate of FIG. 2;

FIG. 4 is an explanatory diagram of a division gate provided in a conventional ore supply unit.

FIG. 5 is a diagram showing a divided gate state for each heat pattern in the width direction,
It is explanatory drawing of the supply condition of the compounding raw material, and supply density in the width direction.

FIG. 6 is a diagram showing a temperature distribution in a width direction heat pattern in a wind box near a point where a combustion front reaches a blade bar in a pallet and in a cross section of a product in an exhaust portion.

FIG. 7 is a view showing an image of a cross section of a pallet of a flat heat pattern.

FIG. 8 is a diagram showing an image of a pallet cross section of an inverted V-shaped heat pattern.

FIG. 9 is a diagram showing changes in specifications for each heat pattern in the width direction when the flat heat pattern is set to zero.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 pallet 13 compounding material hopper 15 bedding ore 16 compounding material 17 ignition furnace 33 cutting gate

Claims (1)

(57) [Claims] 1. After supplying a blended raw material from an ore supply unit onto a pallet with a bedding ore at the bottom, the blended raw material is ignited from the front side, and fired sequentially down the pallet as the pallet moves. In the operation method of the sintering machine, the exhaust gas temperature in the width direction of the wind box near the point where the combustion front reaches the great bar in the pallet has an optimal heat pattern. The bedding is placed in the center of the pallet except for 10 to 30% on both sides of the pallet.
The thickness of the concave portion is 20 to 100 mm, and the pitch of the convex portion is 20.
A method for operating a sintering machine, wherein the sintering machine has an uneven shape of 0 to 400 mm.