JP2000065483A - Sintering pallet for sintering machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of an unburned part at an extended corner provided with an air flow impermeable plate. SOLUTION: An air flow passage 23 is arranged at a lower end of a sidewall 17. Atmospheric air is sucked from an air suction hole 33 of the passage 23. The sucked air is exhausted from an air exhaust hole 34 to a sintering raw material deposited on a lower layer corner on air flow impermeable plates 23 of both sides of the air flow suction area of a pallet fire grate 16. Accordingly, an unbaked part 31 is eliminated, and also flow of excess air to a near area of the sidewall 17 can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention expands the width of a raw material loading surface by providing airflow impermeable plates on both sides of an airflow suction area of a pallet grate and arranging sidewalls outside the airflow impermeable plates. A sintering pallet in a sintering machine.

[0002]

2. Description of the Related Art In a process for producing a sinter which is charged into a blast furnace, a DL type sintering machine which sucks air downward is often used. As shown in FIG. 3, the sintering raw material 1
Is continuously supplied from a raw material hopper 2 to a sintering pallet 7 through a drum feeder 3 and a sloping plate 5,
By rotating the material supply side sprocket 4, the sintering pallet 7
The upper sintering raw material layer 8 is moved at a low speed in the direction of the arrow, and at the same time, a large number of wind boxes 9 arranged below the sintering pallet 7 are suctioned by the exhaust fan 12 via the exhaust gas duct 10 and the dust collector 11. Then, the surface of the sintering material layer 8 on the pallet 7 is ignited by the ignition furnace 6.

[0003] The sintering raw material layer 8 ignited on the surface causes the sintering reaction to shift downward by air passing downward from the surface as the sintering pallet 7 moves, and the whole layer reaches the mining part. Sintering reaction is terminated to continuously produce sintered ore. As shown in FIGS. 4 to 6, a pallet grate 16 is removably supported on a pallet body beam 13 constituting the sintered pallet 7, and a side wall 17 is removably supported on a pallet side wall 14. Pallet body beams 13 arranged between the pallet side walls 14 located on both sides in the width direction of the sintered pallet 7
The head 18 is covered with a wear-resistant and heat-insulating insulation cover 19. A large number of pallet grate 16 are sequentially set between the pallet body beams 13, and a slit-shaped gap formed between the pallet grate 16 serves as a ventilation path. Wheels 20 are provided on the pallet side wall 14, and the sintering pallet 7 runs on the track 15 via the wheels 20. A seal bar 21 is incorporated in a lower portion of the pallet side wall 14 so as to prevent air leakage by sliding with a fixed-side wear bar 22 provided at the upper end of the wind box 9.

In this sintering machine, sidewalls are
At both ends near 17, the wind speed rises from the center of the sintering material layer due to the wall effect, and excessive air flows. Side wall 17
Is increased because the porosity between the raw material particles and the side wall surface is larger than when the raw material particles are filled with each other. Furthermore, as the sintering of the sintering material layer 8 proceeds, the sintering material shrinks due to shrinkage, so that a gap is generated in the side wall portion, which promotes excessive air flow. Therefore, the sintering time in the vicinity of the side wall 17 of the pallet 7 is shorter than that in the center, the necessary sintering reaction at both ends is not sufficiently performed, and the center of the pallet 7 is unbalanced due to the air volume distribution imbalance. In this case, a shortage of air occurs, which adversely affects the sintering reaction in the central region, and deteriorates the yield of sintered ore.

In order to solve this problem and at the same time to improve the productivity, a sintering method for enlarging the material loading surface of the sintering pallet in the width direction has been implemented. For example, Japanese Patent No. 2538158 discloses a pallet grate. A technique is disclosed in which airflow impermeable plates are provided on both sides of an airflow suction area of the above, and the width dimension of the raw material loading surface of the sintering pallet is increased. FIG. 2 shows an example of a sintering pallet provided with an air-impermeable plate.

That is, airflow impermeable plates 23 are provided on both sides of the airflow suction area where the pallet grate 16 is provided, and the side walls 17 are arranged outside the airflow impermeable plates 23 to load the raw material. The width dimension on the surface is enlarged. Note that the upper surfaces of the pallet grate 16 and the airflow impermeable plate 23 are at the same level. Air-impermeable plate 23
The upper plate 24 and the lower plate 26 are integrally formed by a connecting member 25, are attached to the upper end of the pallet side wall 14 using bolts and nuts 27, and another portion is provided on the side surface of the pallet side wall 14. It is attached to the bracket 29 using bolts and nuts 28 together with the side wall 17 and is detachable.

As disclosed in the above-mentioned Japanese Patent No. 2538158, if the width of the pallet is increased by providing air-impervious plates 23 on both sides of the air-flow suction area where the pallet grate 16 is provided, the wall effect near the sidewall 17 can be improved. , The width of the material loading surface of the sintering pallet 7 can be increased, and the amount of sintering material can be increased. However, the ventilation sucked from the air current suction area of the pallet grate 16 into the pallet side wall 14 becomes extremely poor in the vicinity immediately above the air flow impermeable plate 23. That is, the sintering raw material layer 8
Most of the sintering portion 30 forms the sintering portion 30, whereas in the lower corner portion of the sintering material immediately above the airflow impermeable plate 23, the combustion of coke mixed with the sintering material is hindered and the unburned portion
There was a problem that the productivity of sinter decreased due to occurrence of 31.

To solve this problem, Japanese Patent Laid-Open No. 10-1
In the publication of No. 7947, when producing a sinter with a sintering machine having a widened portion with respect to the pallet grate surface, the filling layer thickness of bedding ore formed below the sintering raw material layer is usually 10-15 mm to 20 mm.
There is disclosed a technique for ensuring ventilation of the lower layer portion of the widened portion by increasing the thickness to 50 mm.

[0009]

As described above, if the thickness of the bedding bed to be charged below the sintering raw material layer is set to 20 to 50 mm, ventilation at the widened portion can be ensured. However, the bedding is itself extracted from the sintered product, and the increase in the bedding increases the amount of circulation to the sintering machine, and the sintering supplied to the next process There is a problem that productivity of the sintering machine is hindered because the amount of ore is reduced.

According to the present invention, when the pallet grate is provided with air-impervious plates on both sides of the air-flow suction area to increase the width of the pallet, coke combustion deteriorates due to poor ventilation at the lower corners of the air-impervious plates. The purpose of the present invention is to solve the problem that unburned portions are generated.

[0011]

According to a first aspect of the present invention, there is provided a pallet grate having an airflow impermeable plate on both sides of an airflow suction area, and a sidewall provided outside the airflow impermeable plate. In a sintering pallet in which the width dimension of the material loading surface on which is disposed is enlarged, an air flow passage having an air discharge hole is provided at a lower end portion of the sidewall at a position facing a lower corner portion of the airflow impermeable plate. It is a sintering pallet in a sintering machine characterized by the following.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, an airflow opaque plate 23 is provided on both sides of an airflow suction area in which the pallet grate 16 is provided, and a sidewall 17 is arranged outside the airflow opaque plate 23. The width dimension of the raw material loading surface is enlarged as in the conventional structure shown in FIG. Further, the airflow opaque plate 23 has an upper plate 24 and a lower plate 26 integrally formed by a connecting member 25, and bolts and nuts 27 are provided on the upper end of the pallet side wall 14.
Similarly, the other portion is attached to a bracket 29 provided on the side surface of the pallet side wall 14 together with the side wall 17 using a bolt and nut 28.

In the present invention, a number of air flow passages 32 are provided at the lower end of the sidewall 17 along the pallet longitudinal direction. The air flow passage 32 includes an outer upper air intake hole 33 and an inner lower air discharge hole 34, and the air discharge hole 34 is opened at a position facing the lower corner portion on the airflow impermeable plate 23. . Air flow passage 32 at the bottom of sidewall 17
In order to provide such a structure, for example, it is preferable that the side wall 17 has a structure in which the inner wall material 17A and the outer wall material 17B are overlapped, and a structure in which these are assembled.

An air flow passage 32 is provided below the inner wall material 17A.
The outer wall material 17B is provided with an air suction hole 33, and when the two are overlapped, the groove lower end of the air flow passage 32 formed by the inner wall material 17A and the outer wall material 17B are formed. Thus, an air discharge hole 34 is formed.
Bolt the inner wall material 17A and the outer wall material 17B
If integrated with nuts, the required number of air intake holes 33
In addition, an air flow passage 32 having an air discharge hole 34 can be disposed in the longitudinal direction of the pallet.

It is preferable that the air suction hole 33 and the air discharge hole 34 have a circular cross section, and the groove in the middle of forming the air flow passage 32 has a rectangular cross section. The groove formed in the inner wall material 17A may be a header extending along the longitudinal direction of the side wall 17, and may be common to the many air suction holes 33 and the air discharge holes 34. The 33 and the air discharge hole 34 can be formed in an appropriate shape such as a long hole (slit hole). In some cases, an air discharge hole 34 having a simple structure in which the air suction hole 33 and the air flow passage 32 are directly connected horizontally can be used.

Next, the operation of the present invention will be described. In the raw material deposition layer near the sidewall 17 of the sintering raw material layer 8 deposited on the sintering pallet 7, the wind speed increases from the center of the pallet due to the wall effect, and air tends to flow excessively. The pallet grate 16 is provided with air-impervious fire plates 23 on both sides of the air-flow suction area 16 to prevent excess air from flowing into the sedimentary layer at the widened portion.
Plays its original role. This allows air-impervious plates
Except for the lowermost layer deposition material in the widening corner portion immediately above the vicinity of 23, a good sintering portion 30 is formed for the most part (see FIG. 2).

On the other hand, the lower corner portion immediately above the airflow impervious plate 23 forms an unsintered portion 31 indicated by a chain line because the air sucked by the airflow suction area of the pallet grate 16 is extremely poor. There was a problem. In the present invention,
Since the air flow passage 32 is provided at the lower end of the side wall 17, outside air existing outside the side wall 17 is sucked into the air flow passage 32 by suction negative pressure from the air flow suction area of the pallet grate 16. The air is sucked into the holes 33, discharged from the air discharge holes 34 to the lower corner portion, and combustibles such as coke are burned by air passing through the deposition material at the time when the temperature is raised to the ignition temperature. Is reduced or eliminated. The air passing through the air passage 32 is heated and heated through the sidewalls 17 by the heat of the high-temperature sintering layer existing on the sintering pallet 7, thereby promoting the combustion of coke. The effect is also obtained.

As a result, as compared with the case where the conventional airflow impermeable plate 23 is installed, the air supplied from the airflow passage 32 provided below the sidewall 17 exists on the airflow impermeable plate 23. Unburnt raw material in the lower corner portion is eliminated. At the same time, the uniform sintering reaction in the width direction of the pallet is promoted by eliminating the non-uniform air volume distribution in the width direction both end regions and the center region of the sintering raw material layer 8 by the airflow impermeable plate 23, so The yield improvement is achieved. At this time, the amount of ventilation required to eliminate the unburned portion 31 depends on the suction negative pressure from the airflow suction area of the pallet grate 16, the resistance to the flow of raw materials, and the air suction holes 33, the airflow passages 32 and the air discharge holes 34. It is set according to conditions such as the inner diameter and the ventilation resistance. In some cases, the air discharge holes 34 may be arranged in two or more stages in the height direction and in multiple stages.

The sintering area of the sintering pallet 7 shown in FIG.
^2. Pallet grate in sintering machine with pallet width of 5m
250mm wide air opaque plates on both sides of 16 air suction areas
23 will be provided. And the inner diameter 30
Cross-sectional area with air inlet hole 33 and air outlet hole 34 of mmφ
A groove forming an air flow passage 32 having a square cross section of 500 mm ² was provided.

At this time, the position of the air discharge holes 34 is one row at a height of 50 mm from the upper surface of the airflow impermeable plate 23, and the distance of the air flow passage 32 from the air suction holes 33 to the air discharge holes 34 is 200 mm. The air suction holes 33, the air flow passages 32 and the air discharge holes 34 are separated by a distance of 100 m in the longitudinal direction of the sintering pallet 7.
The sintering operation of the present invention example was performed by arranging a large number at an m pitch. For comparison, an air flow passage 32 is provided below the sidewall 17.
A conventional sintering operation was performed in which an airflow impermeable plate 23 of the same size was provided without disposing the sintering plate.

As a result, in the example of the present invention, the yield was improved by 2% as compared with the conventional example. In each case, the thickness of the sintering raw material layer 8 deposited on the sintering pallet 7 was set to 600 mm.
The suction negative pressure and the air volume of the exhaust fan were 1900 mmAq and 30,000 m ³ / min, respectively.

[0022]

As described above, according to the present invention, an air flow passage is provided at the lower end portion of the sidewall, the outside air is sucked through the air flow passage, and the suction air is supplied to the air-impermeable fire plate. Since it discharges to the sintering material deposited in the upper lower corner, it not only eliminates the unfired part, but also suppresses the excessive flow of air to the area near the sidewall by the air-impervious fire plate. it can. For this reason, uniform sintering in the pallet width direction is achieved, thereby improving the yield of sinter ore and the productivity.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a width direction of a sintering pallet in a sintering machine of the present invention.

FIG. 2 is a cross-sectional view in the width direction showing a sintering pallet in a conventional sintering machine.

FIG. 3 is an overall layout view showing a conventional sintering machine.

FIG. 4 is a sectional view showing a width direction of a sintering pallet in a conventional sintering machine.

FIG. 5 is a sectional view showing a longitudinal direction of a sintering pallet in a conventional sintering machine.

FIG. 6 is a cross-sectional view showing a width direction side end of a pallet truck in a conventional sintering machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sintering raw material 2 Raw material hopper 3 Drum feeder 4 Drive side sprocket 5 Sloping plate 6 Ignition furnace 7 Sintering pallet 8 Sintering raw material layer 9 Wind box 10 Exhaust gas duct 11 Dust collector 12 Suction exhaust fan 13 Pallet body beam 14 Pallet side wall 15 Track 16 Pallet grate 17 Side wall 18 Head 19 Insulation cover 20 Wheel 21 Seal bar 22 Wear bar 23 Air opaque plate 24 Upper plate 25 Connecting member 26 Lower plate 27, 28 Bolt / nut 29 Bracket 30 Firing unit 31 Unfired Part 32 Air flow passage 33 Air intake hole 34 Air discharge hole

Claims (1)

[Claims] 1. A sintering pallet in which an airflow impervious plate is provided on both sides of an airflow suction area of a pallet grate, and a sidewall is arranged outside the airflow impervious plate to increase a width dimension of a raw material loading surface. A sintering pallet in a sintering machine, wherein an air flow passage having an air discharge hole is disposed at a lower end portion of the sidewall at a position facing a lower corner portion on the airflow impermeable plate.