JP2000144269A - Improvement of gas permeability in width extended part of pallet in sintering machine and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a pallet floor area with a flat blind plate, to secure the gas permeability of raw material on the flat blind plate and to reduce unburning part caused by shortage of the gas permeability. SOLUTION: The pallet 16 is extended in its width by arranging the flat blind plates 9 at both sides of a gas permeable fire grate and bedding ore 15 is charged on the gas permeable fire grate 1, and on the other hand, good gas permeable bulky ore 28 is charged as the bedding on the flat blind plates 9 and further, sintering blended raw material layer 24 is formed on the bedding ore 15 and the bulky ore 28. The bulky ore 28 charged on the flat blind plates 9 forms gap between the lower surface of the sintering blended raw material layer 24 and the upper surface of the flat blind plate 9 and the suitable gas permeability from a shrinkage gap 8 of the pallet side wall 2 toward the gas permeable fire grate 1 can be obtd. Then, the gas permeability near the flat blind plate 9 is improved and the unburning part on the flat blind plate 9 is eliminated, and the improvement of yield of the sintered ore is achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ventilation of a widened portion of a pallet in a sintering machine in which a pallet is widened by providing flat blind plates on both sides of a permeable grate and a sintering compound material layer is formed on the pallet. The present invention relates to a method and apparatus for improving the performance.

[0002]

2. Description of the Related Art In a downward suction type sintering machine for producing sinter to be charged into a blast furnace, as shown in FIG. 6, bedding ore 15 is cut out from a drum feeder 14 provided below a bedding hopper 13. ,
The pallet 16 is laid as a protective material for the air-permeable grate 1 forming the floor surface. Next, from a raw material hopper 17, a sintered mixed raw material 7 obtained by mixing fine iron ore, limestone, serpentine, mill scale and other auxiliary raw materials, and solid fuel such as coke breeze is cut out by a drum feeder 18, and is then subjected to a sloping plate.
The sintering compound raw material layer 24 is formed by supplying the sintering compound raw material 15 onto the bedding ore 15 through 19.

[0003] Sprockets arranged before and after the pallet 16
By rotating 20, the sintering compound material layer 24 on the permeable grate 1 is moved in the direction of the arrow at a low speed. At the same time, a suction type air blower 23 via an exhaust gas duct 22 from a suction air box 4 forming a lower portion of the pallet 16 and a large number of fixed hoods 11 arranged therebelow.
The surface of the sintering compound material layer 24 on the gas permeable grate 1 is ignited by the ignition furnace 21 while the air is sucked. The sintering compound material layer 24 ignited on the surface causes the sintering reaction to move downward by air passing downward from the surface as the pallet 16 moves. The sintering reaction is completed for all layers before reaching the discharge portion, and continuously formed into a cake-like sintered ore 25, which is discharged and crushed by a crusher 26.

As shown in FIG. 7, a sintering compound raw material layer 24 containing coke breeze deposited on a gas-permeable grate 1 forming a pallet 16 is surrounded on both sides by pallet side walls 2. A large number of air-permeable grate 1 are set at the boundary between the pallet side wall 2 and the suction air box 4, and a slit-shaped gap formed between the air-permeable grate 1 serves as an air passage. palette
A wear bar 27 runs on the rail 6 via the wheels 3 on both sides and is provided at the lower end of the suction air box 4 and the upper end of the fixed hood 11.
And an air seal bar 5 is set between them to prevent air leakage due to sliding.

In the sintering by the downward suction type sintering machine, the wind speed in the vicinity of the side wall 2 of the pallet is higher than that in the center in the width direction of the sintering compound material layer 24 due to the wall effect, and excessive air flows. This is due to the fact that the porosity of the sintering compound raw material layer 24 is larger at the side wall of the pallet than at the center where the raw material particles are sufficiently filled. Further, as the sintering / mixing raw material layer 24 progresses, the sintering / mixing raw material layer 24 is shrunk, so that the shrinkage gap 8 is generated in the side wall portion, which promotes excessive air flow. For this reason, in the vicinity of the pallet side wall 2, the sintering time is shortened due to excess air compared to the central portion, and sufficient sintering is not performed at both ends, and furthermore, the lack of air in the central portion is reduced. The sintering reaction has an adverse effect on the sintering reaction, which causes a reduction in the yield of the sinter.

To solve this problem, for example, Japanese Unexamined Patent Publication No. 5-71879 discloses a pallet 16 as shown in FIG.
In order to increase the width of the pallet side wall 2 without changing the width of the suction wind box 4 forming the suction portion, a flat blind plate 9 is installed outside the air-permeable grate 1 to increase the floor area, and the vicinity of the pallet side wall 2 For improving the productivity of sinter ore by reducing the flow rate of air passing therethrough. Also, Japanese Patent Application Laid-Open No. 9-12165 and
In Japanese Patent Application Laid-Open No. 186499, as shown in FIG. To This discloses a configuration in which the amount of passing air near the pallet side wall 2 is reduced, and the unevenness of the wind speed in the width direction of the pallet 16 is suppressed.

[0007]

In the prior art disclosed in the above publication, when a flat blind plate is installed on a widened portion provided outside a grate, the flat blind plate is provided near the side wall of the pallet. Therefore, not only ventilation passing in the vertical direction, but also ventilation along the upper surface of the planar blind plate is prevented. Therefore, although the shortening of the sintering time due to the ventilation near the side wall of the pallet is suppressed, a portion where almost no air flows into the sintering compound raw material existing in the immediate vicinity of the planar blind plate occurs, and an unburned portion remains, and the However, there is a problem that is hindered.

On the other hand, as described in Japanese Patent Application Laid-Open No. 9-12165, the width of the suction portion is made smaller than the width of the gas-permeable grate of the pallet, so that the pallet side wall is formed below the gas-permeable grate. In many cases, a new pallet needs to be manufactured when the amount of air to be sucked into the pallet is reduced, and the pallet has a defect that can be performed only in a special case such as a complete renewal of the pallet. The present invention
A pallet widening method for a sintering machine capable of increasing a grate area by a planar blind plate and securing a gas permeability near the top of the blind plate. It is an object of the present invention to provide a method and apparatus for improving air permeability of a part.

[0009]

According to a first aspect of the present invention, a flat blind plate is provided on both sides of an air-permeable grate to widen a pallet, and a sintering compound material layer is formed on the pallet. A method for improving the air permeability of a pallet widening portion in a sintering machine, wherein a bedding ore is charged on the air-permeable grate and a lump ore as a bedding on the planar blind plate. A sintering compound material is formed on the bedding ore and the lump ore to form a sintering compound material layer.

According to a second aspect of the present invention, while the amount of bedding ore charged into the air-permeable grate is adjusted by the opening degree of a bedding ore gate provided below the bedding hopper, the planar blindness is adjusted. 2. The method for improving air permeability of a pallet widening part in a sintering machine according to claim 1, wherein the amount of lump ore charged on the plate is adjusted by the opening degree of the lump ore gate provided below the floor hopper. is there.

According to the present invention, the temperature of the lump ore charged on the plane blind plate is continuously measured by a thermocouple set above or inside the plane blind plate. The pallet widening section of the sintering machine according to claim 1 or 2, wherein the amount of lump ore charged on the plane blind plate is adjusted based on the measurement temperature by an opening degree of the lump ore gate. This is a method for improving air permeability.

According to a fourth aspect of the present invention, there is provided a pallet widening portion in a sintering machine for widening a pallet by providing flat blind plates on both sides of a gas permeable grate and forming a sintering compound material layer on the pallet. An air permeability improving device, comprising: a bedding ore gate provided at a lower portion of a bedding hopper for charging bedding on the air permeable grate; and a lump ore on the flat blind plate. And a lump ore gate provided at a lower portion of a bedding hopper into which a pallet is inserted so as to be freely adjustable in opening degree.

According to a fifth aspect of the present invention, a thermocouple is provided above or inside the plane blind plate for continuously measuring the temperature of the lump ore existing on the plane blind plate. An apparatus for improving air permeability of a pallet widening portion in a sintering machine according to claim 4.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. In the present invention, as shown in FIG. 1, a number of permeable grate 1 are arranged on the upper part of suction wind box 4 constituting pallet 16 of the downward suction type sintering machine, and both sides of permeable grate 1 are widened. And a detachable planar blind plate 9 is provided there.
The pallet side wall 2 extends upward adjacent to the side edge of the flat blind plate 9. The pallet 16 travels on rails 6 laid on the floor frame 12 via the wheels 3, and air leakage is prevented by the air seal bar 5 provided between the lower end of the suction wind box 4 and the upper end of the fixed hood 11. . The ordinary bedding ore 15 is charged on the air-permeable grate 1, and the lump ore 28 having a large particle size and good air permeability is charged on the flat blind plate 9 as a bedding.
Then, the sintering compound raw material 7 is placed on the bedding ore 15 and the lump ore 28.
To form a sintering compound material layer 24. The sintering process is performed by passing a suction gas flow through the suction air box 4 and the fixed hood 11 through the sintering compound raw material layer 24.

The bedding ore 15 is charged on the air-permeable grate 1 forming the pallet 16 while the lump ore 28 is placed on the plane blind plate 9.
For example, as shown in FIG. 2, a floor hopper is installed corresponding to the width of the breathable grate 1 and the flat blind plate 9 as shown in FIG.
The inside of 13 is divided into three parts by a partition plate 30 in the width direction, and the bedding ore 15 is stored in the center and the lump ore 28 is stored in both sides. Floor hopper
At the exit of 13, there are bedding ore gates 31 in the center and lump ore gates 32 on both sides so as to be able to ascend and descend along each elevating guide 33. It can be moved up and down by an elevating cylinder 34 arranged on the front side wall of the bed hopper 13. Instead of dividing the inside of the bedding hopper 13 into three, it is also possible to arrange three bedding hoppers independently and store the bedding ore 15 and the lump ore 28.

Next, a method for ventilating the sintering compound material layer 24 filled in the widened portion of the pallet 16 in the sintering machine of the present invention will be described. The bedding ore 15 stored in the center of the bedding hopper 13 and the lump ore 28 stored on both sides of the bedding hopper 13 divided into three parts in the width direction by the partition plate 30 are respectively opened by the bedding ore gate 31 and the lump ore gate 32. After adjustment, the drum feeder 14 is rotated and cut out, and the bedding ore 15 is spread on the air-permeable grate 1 and the lump ore 28 is spread on the flat blind plate 9. Next, the sintering compounding raw material 7 is supplied on the bedding ore 15 and the lump ore 28 to form the sintering compounding material layer 24 (see FIG. 1). Since the sintering state of the lump ore 28 existing on the plane blind plate 9 depends on the raw material particle size, brand, and the like, the lump ore must be charged on the plane blind plate 9 in an appropriate amount.

As shown in FIG. 3, the temperature of the lump ore 28 charged on the plane blind plate 9 is continuously measured using a thermocouple 35 set on the top of the plane blind plate 9. Note that a housing hole may be provided inside the planar blind plate 9 and the thermocouple 35 may be set in the housing hole. Lump ore measured by thermocouple 35
The opening degree of the lump ore gate 32 is adjusted using the elevating cylinder 34 based on the temperature data of 28, whereby the plane blind plate 9
The cutout amount of the lump ore 28 charged above is adjusted. Here, if the amount of the lump ore 28 existing on the plane blind plate 9 is small, the amount of air passing through the lump ore 28 becomes insufficient, and an unsintered portion is generated. But expensive lump ore
Use of 28 increases the cost.

Therefore, when the temperature measured by the thermocouple 35 is low, the opening amount of the lump ore gate 32 is increased to increase the cutout amount of the lump ore 28, and the planar blind plate is improved by improving the air permeability. The temperature of the lump ore 28 near 9 is increased. Conversely, when the temperature data of the lump ore 28 measured by the thermocouple 35 is high, the opening amount of the lump ore gate 32 is reduced to reduce the cutout amount of the lump ore 28 and suppress The temperature of the ore 28 is lowered. By maintaining the amount of the lump ore 28 present on the plane blind plate 9 in an appropriate range in this way, the air permeability near the plane blind plate 9 is improved and the predetermined temperature is maintained. The lump ore 28 once heat-treated in the vicinity of the plane blind plate 9 has reduced adhesion moisture and adhesion dust, and has increased strength. It was confirmed that it had a positive effect.

In the present invention, the void formed by the lump ore 28 charged on the plane blind plate 9 enables appropriate ventilation from the shrinkage gap 8 near the pallet side wall 2 toward the breathable grate 1. For this reason, appropriate air permeability is maintained in the vicinity of the planar blind plate 9, and unburnt residue is eliminated. Furthermore, since the unevenness of the air volume distribution in the width direction both end regions and the center region of the sintering compound material layer 24 is reduced, the yield of the sinter is improved.

The present invention relates to a Dwyroid type sintering machine (capacity
13600t / day, sintering area 410m ^2, the distance between the sprockets
94.8m, pallet side wall lower end width 5.0m, flat blind plate width 0.25m x length 1.5m, breathable grate width 5.0m)
Applied to The lump ore is, for example, hematite, magnetite, etc., having a particle size of about 8 to 25 mm, compared to that of ordinary bedding, which has a particle size of 8 to 14 mm. Lump ore is charged at a layer thickness of about 30 to 40 mm, and at the same time, bed bedding (average grain size: 10 mm) is layered on a permeable grate by a layer thickness of about 15 mm
Charge in the degree. Further, a sintering compound raw material of a normal compounding component was charged thereon with a layer thickness of 550 mm. Pallet speed 2.
The sintering process was performed at a temperature of 5 to 3.0 m / min and an exhaust gas temperature of 120 ° C. For comparison with the examples of the present invention, a comparative example in which a flat blind plate of the same size was arranged and ordinary bedrock was charged thereon, and a comparative example in which the planar blind plate was not arranged were performed.

FIG. 8 shows the distribution of wind speed in the pallet width direction during the sintering process in comparison with the present invention example, comparative example and conventional example. As shown in FIG. 8, in the conventional example, there is no suppression of the ventilation of the pallet side wall, and the average wind speed of the side wall is remarkably high due to the wall effect and the contraction gap. In the comparative example, the ventilation of the non-perforated flat blind plate is effective. The average wind speed of the side wall part is too low. On the other hand, in the example of the present invention, air permeability near the plane blind plate 9 made of lump ore became appropriate, and the wind speed in the pallet width direction could be leveled.

Table 1 shows the yield of the sintered ore in the vicinity of the side wall and in the entire pallet in the case of the conventional example, the comparative example, and the example of the present invention.

[0023]

[Table 1]

The yields shown in Table 1 were obtained by tumbling strength tests on samples taken from the center part, both ends, and the middle part between the center and both ends in the width direction of the sintered cake taken out of each pallet after sintering. It is the weight ratio of +5 mm sintered ore after being crushed by the machine. In the example of the present invention, while the wind speed near the side wall was greatly reduced as compared with the conventional example, excessive suppression of the wind speed near the side wall was alleviated as compared with the comparative example, and it was confirmed that the yield of the sintered ore was improved.

[0025]

As described above, according to the present invention, a flat blind plate is provided on both sides of a gas-permeable grate to widen a pallet, and a bedding bed is charged on a gas-permeable grate. In addition, a lump ore with a large particle size and good air permeability is charged as a bedding on a flat blind plate, and a sintering compound material is charged on the litter ore and the lump ore. The charged lump ore forms a gap between the lower surface of the sintering compound raw material layer and the upper surface of the planar blind plate, and allows appropriate ventilation from the shrinkage gap of the pallet side wall toward the air-permeable grate. For this reason, air permeability near the planar blind plate is improved, and unburned portions due to insufficient sintering near the planar blind plate are eliminated. Furthermore, since the air volume distribution in the width direction both end regions and the center region of the sintering compound material layer is made uniform, the yield of sinter is improved.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing an apparatus for improving air permeability of a pallet widening portion of the present invention.

FIG. 2 is a front view showing a floor hopper and a pallet according to the present invention.

FIG. 3 is a partial cross-sectional view showing another embodiment of the pallet widening portion air permeability improving device of the present invention.

FIG. 4 is a partial cross-sectional view showing a conventional pallet widening portion air permeability improving device.

FIG. 5 is a partial sectional view showing another conventional pallet air permeability improving device.

FIG. 6 is a side view showing the entirety of a conventional Dwyroid type sintering machine.

FIG. 7 is a sectional view showing a width direction of a pallet in a conventional sintering machine.

FIG. 8 is a graph showing the average wind speed distribution in the pallet width direction in comparison with the conventional example, the comparative example, and the example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Breathable grate 2 Pallet side wall 3 Wheel 4 Suction wind box 5 Air seal bar 6 Rail 7 Sintering compound material 8 Shrinkage gap 9 Planar blind plate 11 Fixed hood 12 Floor frame 13 Floor hopper 14, 18 Drum feeder 15 Floor Ore 16 Pallet 17 Raw material hopper 19 Sloping plate 20 Sprocket 21 Ignition furnace 22 Exhaust gas duct 23 Suction exhaust fan 24 Sintering compound raw material layer 25 Sinter ore 26 Crusher 27 Wear bar 28 Lump ore 29 Suction gas flow 30 Partition plate 31 Floorbed Ore gate 32 Lump ore gate 33 Elevating guide 34 Elevating cylinder 35 Thermocouple

Claims (5)

[Claims] 1. A method for improving air permeability of a pallet widening portion in a sintering machine in which a pallet is widened by providing flat blind plates on both sides of a gas permeable grate to form a sintering compound material layer on the pallet. Loading the bedding ore on the air-permeable grate, charging lump ore as a bedding on the planar blind plate, and sintering the mixed raw material on the bedding and the lump ore. A method for improving air permeability of a widened portion of a pallet in a sintering machine, wherein a sintering compound material layer is formed by charging. 2. The amount of bedding ore charged into the air-permeable grate is adjusted by the degree of opening of a bedding ore gate provided at the lower part of the bedding hopper, while lump ore on the plane blind plate is adjusted. 2. The method for improving air permeability of a pallet widening part in a sintering machine according to claim 1, wherein the charging amount is adjusted by an opening degree of a lump ore gate provided at a lower portion of a floor hopper. 3. The temperature of the lump ore charged on the plane blind plate is continuously measured by a thermocouple set on or inside the plane blind plate, and based on the measured temperature, 3. The method for improving air permeability of a pallet widening part in a sintering machine according to claim 1, wherein the amount of lump ore charged on the plane blind plate is adjusted by an opening degree of the lump ore gate. 4. A gas permeability improving device for a pallet widening portion of a sintering machine in which a pallet is widened by providing flat blind plates on both sides of a gas permeable grate to form a sintering compound material layer on the pallet. A bedding ore gate provided at a lower portion of a bedding hopper for charging bedding on the air-permeable grate, the degree of opening of which can be adjusted;
A lump ore gate provided at a lower portion of a floor hopper for charging lump ore on the planar blind plate so as to be capable of adjusting an opening degree, and a pallet widening portion of a sintering machine having a gas permeability improving device. . 5. The thermocouple according to claim 4, wherein a thermocouple for continuously measuring the temperature of the lump ore existing on the plane blind plate is provided above or inside the plane blind plate. Equipment for improving air permeability of the pallet widening section in a sintering machine.