JPH1183339A - Air leakage-preventing device for sintering machine and method for using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air leakage-preventing device for a sintering machine and a method for using the same, capable of controlling air leakage in the vicinity of side walls of a pallet without remodeling the pallet on a large scale. SOLUTION: An air leakage-preventing device is box-shaped lid-like sealed boxes 3 disposed above a sintering raw material layer 13 or a sintering layer 7, with which a pallet 1 of a moving bed sintering machine is filled, along the longitudinal direction of the sintering machine, and covering a range up to one-fifths of the width of the pallet 1 from side walls 2 of the pallet 1 filled with the sintering raw material layer 13, or the sintering layer 7 toward the central part of the pallet 1. A window whose opening area can be freely regulated is provided on the ceiling of each of the sealed boxes 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing air leakage in a sintering machine and a method for using the same, and more particularly, to a device for preventing air leakage generated during operation of a moving bed type sintering machine such as a Dwight Lloyd sintering machine. This is a technology to reduce as much as possible.

[0002]

2. Description of the Related Art In a Dwight Lloyd type sintering machine, a plurality of so-called pallets 1 in which great bars are arranged in a lattice are connected in a ring to form a moving bed, and the moving bed is a wind box (not shown). It is formed to move endlessly on a wind box that is sucked downward. Then, in this sintering machine, for example, to sinter and lump fine iron ore,
The following operations are performed.

First, as shown in FIG. 2, a mixture of ore powder, coke powder, limestone and the like is filled on the moving bed to form a sintering raw material layer 13, and the coke powder contained in the upper layer is formed. Ignite. Since the wind box has a negative pressure, the fire moves downward, and the combustion of the coke powder proceeds from the upper layer to the lower layer of the sintering raw material layer 13. Accordingly, the temperature of the sintering raw material layer 13 increases, and the iron ore powder melts using limestone as a flux and sinters each other. In the meantime, since the pallet 1 is moving in the horizontal direction, when the sintering machine is viewed in a longitudinal section, as shown in FIG. 4A, the sintering material layer 13 is on the lower side and the sintering completed layer is on the upper side. 7 (hereinafter referred to as a sintered layer).
The boundary between the sintering material layer 13 and the sintering layer 7 (curve H)
) Is the most intensely combusted part and is called the heat front 15, and the adjustment of the time it takes to reach the upper surface of the pallet 1 will greatly affect the performance of the sintering operation. The position where the heat front 15 reaches the upper surface of the pallet 1 is referred to as a lowermost firing point (burn-through point) 14.

In the sintering operation described above, the sintering raw material layer 13 which is initially filled is reduced in its voids by sintering, and becomes a sintered layer 7 which is hardened. As a result, a large gap 1 extending vertically between the side wall of the pallet (referred to as side wall 2) and the sintered layer 7.
0 is formed. The airflow resistance of the gap 10 is significantly smaller than that of the sintering raw material layer 13 or the sintering layer 7. Therefore, when this gap 10 is formed during operation,
The amount of air flowing in that portion increases, and the amount of air passing in the sintering raw material layer 13 or the sintering layer 7 is locally biased.
That is, in addition to the airflow flowing from top to bottom in the sintered layer 7,
In the sintering raw material layer in the vicinity of the gap, a lateral airflow that flows toward the gap is generated, and a locally skewed air flow 12 is generated when viewed from the entire sintered layer 7 (see FIG. 3). ).
When such a local deviation occurs in the air flow 12,
Since the combustion of the coke in the vicinity is promoted, the combustion ends earlier than originally required, and as a result, there is a problem that the strength and the yield of the sinter at that portion are reduced. This is because the time during which the sintering raw material is kept at a high temperature is shortened, which not only inhibits the sufficient fusion of the iron ore powder, but also has a large air flow rate, so that the cooling after sintering is accelerated and the sintering is accelerated. It is considered that the thermal shock to the tie layer 7 increases, and fine cracks are generated in the sintered layer 7 itself.

In the sintering operation, such local drift flowing in the gap 10 is regarded as a kind of air leakage. This kind of air leakage does not only contribute to the sintering of the entire sintered layer 7,
If the amount is large, an extra capacity of a blower (not shown) for making the inside of the wind box a negative pressure is required, which increases power consumption and is not economically preferable.

Therefore, Japanese Patent Application Laid-Open No. Sho 59-80735 discloses that when such a gap is formed in a sintering raw material layer or a sintering layer during an operation, an iron plate is placed on the upper surface of the gap and sealed. Disclosed measures. Also, Japanese Patent Application Laid-Open No. 61-173
No. 072 discloses that the wind box is divided into three in the width direction of the sintering machine, the negative pressure of the wind box at both ends is made smaller than that at the center, and flows through a gap formed near the side wall of the pallet. A method to reduce air leakage is proposed.

[0007]

However, the countermeasure described in Japanese Patent Application Laid-Open No. Sho 59-80735 is to prevent air leakage by covering the gap or the upper opening of a crack partially occurring in the sintered layer with an iron plate. However, as shown in FIG. 3, the gap 10 has an air flow 12 from the side surface via the sintered layer 7 around the gap 10. In particular, in the gap 10 where the amount of air leakage generated between the sintered layer 7 and the side wall 2 is large, the sintered layer 7 ranging from the side wall 2 to 1/5 of the pallet width has Since the air flow in the sintering layer 7 is strong, simply covering the upper surface of the gap 10 with an iron plate can speed up the coke combustion rate due to the air flow 12 and prevent the strength and yield of the sinter from lowering. Can not. Although the method described in Japanese Patent Application Laid-Open No. Sho 61-173072 can compensate for the drawback of using the iron plate to some extent, the sealing structure between the upper end of the dividing wall of the wind box and the moving pallet is complicated. It had the disadvantage of requiring a large capital investment for remodeling.

The present invention has been made in view of the above circumstances, and provides an air leakage prevention device for a sintering machine capable of suppressing air leakage near a side wall without large-scale remodeling and a method of using the same. The purpose is.

[0009]

Means for Solving the Problems In order to achieve the above object, the inventor examined the relationship between the operation of the sintering machine and the air leakage generated near the side wall of the pallet during the operation, and obtained the knowledge obtained. Was arranged as follows. When the air leak occurs near the side wall, the combustion of the coke in the sintering raw material layer 13 in the vicinity is accelerated, and the combustion easily reaches the lowermost end. Therefore, the lowermost firing point 14 shown in FIG.
Moves to the mining side. On the other hand, in the sintering raw material layer 13 which is not affected by the air leakage, the original burning speed of coke is maintained, so that the lowermost sintering point 14 as shown in FIG. A distribution is formed. This suggests that, when the upper to lower layers of the sintering raw material layer 13 are viewed as a large number of horizontal planes, a distribution also occurs at the highest point of coke combustion (heat front 15) on each horizontal plane. I have.

The lowermost firing point 14 or heat
The width distribution of the sintering machine at the front 15 is currently
In the lower wind box and in the longitudinal direction and the width direction of the sintering machine, a lattice shape (indicated by a cross in FIG. 4B)
It is thought that it can be grasped by installing a thermometer 16 at the bottom. Therefore, the inventor focused on correcting the distribution of the lowermost sintering point 14 or the heat front 15 in the width direction of the sintering machine in order to reduce the amount of air leakage, and made various experiments. As a result, by sealing the upper surface of the sintering raw material layer 13 or the sintering layer 7 from the side wall 2 having a large amount of air leakage to the center to １ ／ of the pallet width and appropriately changing the sealing area, It has been confirmed that not only the amount of air leakage can be reduced, but also that the distribution of the heat front 15 and the like is corrected, and the present invention has been completed.

That is, according to the present invention, a sintering material layer or a sintering layer filled in a pallet of a moving bed type sintering machine is disposed along the longitudinal direction of the sintering machine. A box-shaped lid seal covering a range of up to 1/5 of the pallet width from the side wall of the pallet of the sintered layer to the center.
An air leakage prevention device for a sintering machine, wherein a window having an adjustable opening area is provided on a ceiling of the seal box.

Further, the present invention is an air leakage prevention device for a sintering machine, wherein a large number of thermometers are arranged in a lattice shape on the lower surface side of the pallet and in the longitudinal and width directions. Further, the present invention provides a sintering material layer and / or a gap between sintering layers formed on a pallet of a moving bed type sintering machine due to compaction of the sintering material layer as the sintering reaction progresses. In order to prevent air leakage from the pallet, the temperature under the sintered layer was measured with a large number of thermometers arranged in a grid on the lower surface side of the pallet, and the temperature distribution in the width direction was obtained from the measured values. The method according to claim 1, wherein an opening area of a window provided on a ceiling of the seal box is adjusted so that the width is uniform in a width direction.

In addition, according to the present invention, the temperature distribution is calculated from the position of 1/2 of the effective sintering machine length (the distance from the ignition position to the ore mining part) in the pallet advancing direction from the sintering machine ignition furnace position. It is also a method of using the air leakage prevention device for a sintering machine, which is characterized in that it seeks up to an exhaust portion. According to the present invention, the seal area of the seal box disposed near the side wall is adjusted so that the temperature distribution in the width direction of the sintered layer becomes uniform. It can be reduced. As a result, the lowermost firing point of the sintered layer could be made substantially uniform in the width direction of the sintering machine, and the strength and yield of the product sintered ore were improved, and the productivity was also increased.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. First, the air leakage prevention device according to the present invention has a configuration as shown in FIG. It is pallet 1
Sealing surfaces (hereinafter referred to as ceiling sealing surface 5, outer sealing surface 6, inner sealing surface 21, and two traveling direction sealing surfaces 20) covering the upper surface of the sintering raw material layer 13 or the sintering layer 7 near the side wall 2 of FIG. Box-shaped seal with
Box 3. Its size ranges from the side wall 2 to the center of the sintering machine up to 1/5 of the pallet width in the width direction of the sintering machine, and from the ignition furnace position in the longitudinal direction. It covers only up to one third of the effective sintering machine length. On the ceiling sealing surface 5 corresponding to the ceiling of the sealing box 2, a window 18 and a lid 19 for adjusting the opening area of the window so that the sealing area can be variously changed.
Are provided. It is preferable in terms of adjusting operation that a large number of the windows 18 are provided on the ceiling sealing surface 5 so that the opening areas of the windows 18 can be adjusted. For the same reason, the lid 19 for adjusting the opening area is preferably of a sliding type.

The seal box 3 is supported by a support beam 4 straddling the sintering machine. The outer sealing surface 6 at the end in the width direction of the sintering machine has a structure in which it rubs against the side wall 2. Sealed with negative pressure in the box. The so-called inner seal surface 21 on the central portion side is a flexible seal having wear resistance in consideration of the case where irregularities are formed on the upper surface of the sintered layer.
Similarly, the sealing surface 20 in the pallet advancing direction was also a soft-structured seal. Furthermore, rubber,
Synthetic resins and the like are preferred, but mineral fibers such as asbestos and rock wool, or a dense metal network structure can also be used as appropriate.

In the present invention, the size of the seal box 3 is set to a range of 1/5 from the side wall 2 to the center of the sintering machine in the width direction of the sintering machine. The reason is that even if the distance in the width direction exceeds 1/5,
This is because the effect of reducing the amount of air leakage is saturated and equipment is wasted. Next, a method of using the above-described air leakage prevention device according to the present invention will be described.

For this purpose, the thermometer 16 shown in FIG. 4B is used. This thermometer is usually arranged in a wind box on the lower surface of the pallet 1 to measure the ambient temperature. In the example measured in the pallet advancing direction, a temperature distribution as shown in FIG. 5 is obtained. This temperature distribution curve represents the position of the heat front 15 described above, and the position corresponding to substantially the highest point of the curve is the lowermost firing point. Therefore, when the ambient temperature under the pallet 1 is measured in the pallet traveling direction,
The heat front 15 and the lowermost firing point 14 of the sintered layer 7 can be estimated. When measured in the pallet width direction, the heat front 15 and the lowermost firing point 1 in the pallet width direction can be estimated.
4 can be detected.

According to the present invention, the distribution of the heat front 15 and the lowermost firing point 14 during operation is constantly monitored, and the ceiling sealing surface 5 of the sealing box 3 is uniformly distributed in the pallet width direction. Is adjusted to reduce the amount of air leakage near the side wall 2. That is,
By reducing the burning speed of coke in the sintering material layer 13 near the side wall 2, the heat front 1
5 and the lowermost firing point 14 are made uniform in the pallet width direction. In the present invention, the temperature was measured so as to cover the range from the position of 1/2 of the effective sintering machine length to the mining part in the longitudinal direction of the sintering machine. In order to detect the temperature distribution of the heat front 15 and the lowermost firing point 14, it is sufficient to confirm the temperature in the above range.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An air leakage prevention device according to the present invention is 3.5 m wide.
It was applied to the operation of a Dwight Lloyd type sintering machine with an effective sintering length of 60 m. At that time, the production volume was 7000
The operation was performed on a ton / day scale. The seal box 3 has the shape shown in FIG. 6, and the installation range is from the side walls 2 of the pallet 1 to the center and the width is 0.
It was changed at four levels of 3, 0.5, 0.7 and 0.9 m, and was set to 30 m in the machine length direction from the exit side of the ignition furnace. Further, the seal box 3 is a steel box body, and the outer seal surface 6 is brought into direct contact with the side surface of the side wall 2. Further, a rubber seal 17 is attached to a lower portion of the inner seal surface 21 and the traveling direction seal surface 20,
The rubber seal 17 was brought into contact with the upper surface of the sintered layer 7. Further, ten windows 18 having openings of 500 mm × (the width of the seal box) are provided on the ceiling of the seal box 3 at a distance of 2 m in the longitudinal direction, and a sliding lid 19 is installed on each window 18. The opening area is adjusted by shifting the position of the lid 18 according to a command based on the distribution of the heat front 15 and the lowermost firing point 14. The thermometers 16 are installed at positions 300 mm inside the side walls 2 and three rows at the center of the pallet, and 4 m in the pallet advancing direction.
It is every.

The operation was performed by changing the width of the seal box to 0.3, 0.5, 0.7 and 0.9 m in the pallet width direction, and the effect of preventing air leakage was confirmed. At that time, the worker
At each level of the seal box width, while appropriately adjusting the opening area of the ceiling sealing surface 5 based on the degree of sintering of the sinter, the operation aimed at the minimum unit of suction gas was aimed at. FIG. 7 shows the results obtained in the operation. FIG. 7 shows the unit of suction gas when the length of the seal box in the width direction is changed based on the unit of suction gas of sinter during operation without taking measures to prevent air leakage (the present invention). It shows the reduction. According to FIG. 7, when the present invention is implemented as compared with the operation without taking measures against the leakage, if the width of the seal box is 0.7 m or more (corresponding to 1/5 of the pallet width), the effect of preventing the leakage is improved. It turns out that it is big. At this time, the reduction rate of the unit of suction gas by the installation of the air leakage prevention device is 1.0
%, And the sintering yield was improved by 1.1%. This corresponds to an increase of 77 tons / day in production.

The length of the seal box in the pallet width direction is set to 0.7 m (corresponding to 1/5 of the pallet width), and the lowermost baking is performed based on data measured by a thermometer installed below the pallet. The point 14 was estimated as described above, and the operation of adjusting the opening area of the ceiling sealing surface 5 was also performed so that the lowermost firing point 14 in the pallet width direction was substantially uniform in the pallet advancing direction. As a result, the reduction rate of the suction gas basic unit was 1.4%, and the sintering yield was improved by 1.7%.
This corresponds to an increase in production of 98 tons / day.

[0022]

As described above, according to the present invention, it is possible to reduce the air leakage from the gap formed near the side wall of the pallet during the sintering operation. as a result,
The strength and yield of the produced sinter have been improved, and the productivity has also been increased.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an installation state of an air leakage prevention device according to the present invention.

FIG. 2 is a cross-sectional view showing a sintering state on a conventional sintering machine.

FIG. 3 is a conceptual diagram showing an air flow near a side wall of a pallet.

FIG. 4 is a conceptual diagram showing a sintering state on a sintering machine;
(A) is a sectional view in the longitudinal direction of the sintering machine, and (b) is a plan view.

FIG. 5 is a diagram showing a temperature distribution of an atmosphere under a pallet in a longitudinal direction of a sintering machine.

FIG. 6 is a perspective view showing an example of a wind leakage prevention device according to the present invention.

FIG. 7 is a diagram showing the effect of the present invention in terms of a reduction rate of a unit of suction gas.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pallet 2 Side wall 3 Seal box 4 Support beam 5 Ceiling sealing surface 6 Outer sealing surface 7 Sintered layer 8 Mineral hopper 9 Feeder of raw material 10 Gap 11 Ignition furnace 12 Air flow from side 13 Sintered raw material layer 14 Lowermost firing point (burn through point) 15 Heat front 16 Thermometer 17 Rubber seal 18 Window (opening) 19 Lid 20 Progression side seal surface 21 Inner seal surface

Claims (4)

[Claims] A sintering material layer or a sintering layer filled in a pallet of a moving bed type sintering machine is disposed along the longitudinal direction of the sintering machine, and the sintering material layer or the sintering layer is provided. A box-shaped lid-shaped seal box that covers a range from the side wall of the pallet to a central part up to 1/5 of the pallet width, wherein a ceiling is provided on the ceiling of the seal box with a window having an adjustable opening area. An air leakage prevention device for a sintering machine. 2. The air leakage prevention device for a sintering machine according to claim 1, wherein a large number of thermometers are arranged in a grid on the lower surface side of said pallet and in the longitudinal and width directions. 3. A sintering raw material layer formed on the pallet of a moving bed type sintering machine due to the compaction of the sintering raw material layer as the sintering reaction progresses and / or a gap between the sintered raw material layers. In preventing the air leakage, the temperature under the sintering layer was measured with a number of thermometers arranged in a lattice on the lower surface side of the pallet, and the temperature distribution in the width direction was obtained from the measured values, and the temperature distribution was A method for using an air leakage prevention device for a sintering machine, wherein an opening area of a window provided on a ceiling of the seal box is adjusted so as to be uniform in a width direction. 4. The sintering apparatus according to claim 3, wherein said temperature distribution is determined from a position of 1/2 of an effective sintering machine length to a mining part in a pallet advancing direction from an ignition furnace position of the sintering machine. How to use the leak prevention device of the machine.