JP2003314966A - Pallet truck for sintering machine and its air permeability adjusting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pallet truck for a sintering machine and its air permeability adjusting method wherein the permeability in the vicinity of a pallet side wall is reliably suppressed without impairing productivity. <P>SOLUTION: In this lower suction type pallet truck 15 for the sintering machine and its air permeability adjusting method, a non-permeable plate 10 is provided to both side parts of a permeable grate 16 provided at a center part in a width direction of the pallet truck 15 for the sintering machine, a bedding ore is layed over the non-permeable plate 10 and the permeable grate 16, and a sintering raw material is layed over the bedding ore. The pallet truck 15 is provided with a step Y where a top face position of the non-permeable plate 10 is lower than that of the permeable hearth 16 to adjust the permeability at a side of the pallet truck 15. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pallet truck for a sintering machine and a method for adjusting its air permeability.

[0002]

2. Description of the Related Art In a Dwightroid type (downward suction type) sinter machine for producing sinter ore charged into a blast furnace, as shown in FIG. Bedbed ore 2 is loaded on a pallet trolley 3, and a sintering raw material 4 (powdered iron ore, powdered limestone, etc. and powdered coke, etc.) is mixed on the pallet truck 3. (Raw material) is sequentially charged from the raw material hopper 5 through the drum feeder 6 and the charging device 7 to form the sintering raw material layer 8. Then, the surface of the sintering raw material layer 8 is ignited by an ignition furnace 9 provided above the pallet truck 3, and the pallet truck 3 is further ignited.
Inhaled from below. As a result, the surface-ignited sintering raw material layer 8 shifts the sintering reaction downward by the air passing downward from the surface with the movement of the pallet truck 3, and the sintering raw material layer 8 is entirely sintered while reaching the discharge portion. After the reaction is completed, cake-shaped sinter is continuously discharged. The charging of the bed mat ore is effective for preventing the sintering raw material from spilling from between the breathable fire beds of the pallet trolley 3 and the sintering raw material containing the heat source (powder coke) is directly breathable. This is to prevent the material from coming into contact with and welding (a phenomenon in which the raw material melts and remains attached to the fire bed and does not separate).

In the sintering by the Dwightroid type sintering machine, the vicinity of the side wall of the pallet truck 3 (hereinafter referred to as the pallet side wall) has a better air permeability than the center portion in the width direction of the sintering raw material layer 8 due to the wall effect, and excessively. The air flows. This is because the sintering raw material layer 8 in the central portion in the width direction of the pallet truck 3 and the sintering raw material layer 8 in the vicinity of the pallet side wall have different porosities, and the pallet side wall is larger than the central portion in which the raw material particles are sufficiently filled. This is because the porosity is large in the vicinity. Further, the sintering raw material is burned as the sintering of the sintering raw material layer 8 progresses, so that a shrinkage gap is generated in the vicinity of the side wall, which promotes excessive air flow. Therefore, in the vicinity of the pallet side wall of the pallet truck 3, the sintering time is shortened by the excess air, the necessary sintering reaction is not performed at both ends, and the central portion is deficient in air, which adversely affects the sintering reaction. This will affect the yield of the sintered ore. In order to solve this problem, Japanese Patent Laid-Open No. 3-211240 discloses that the bed ore loaded on the pallet truck is changed in the pallet width direction.
A method of making the air permeability in the pallet width direction uniform has been proposed. Further, Japanese Patent Laid-Open No. 5-71879 proposes a method of installing a non-breathable plate near the side wall of a pallet to suppress air permeability near the side wall of the pallet so as to make the air permeability in the pallet width direction uniform. Has been done.

[0004]

However, in the method disclosed in Japanese Patent Laid-Open No. 3-211240, the bed thickness of the bed ore at the center of the pallet in the width direction is increased. However, there is a problem in that the productivity decreases and productivity drops.
Also, rather than suppressing the amount of air that has flowed in from the side wall of the pallet, it is a method of increasing the amount of air in the central part and making the air flow rate uniform, so basically the amount of air per unit raw material increases and the electricity consumption rate deteriorates. I have a problem to do. Further, in the method disclosed in Japanese Patent Laid-Open No. 5-71879, since the bed ore is uniformly loaded in the pallet width direction, the air flowing in from the vicinity of the pallet side wall passes through the bed ore layer and flows through the center of the pallet width direction. Since it flows into the breathable fire bed, even if a non-breathable plate is installed near the side wall of the pallet, it is not possible to obtain the effect of significantly suppressing the breathability near the side wall of the pallet. An object of the present invention is to reliably suppress air permeability near the side wall of a pallet without impeding productivity.

[0005]

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems, and means 1 thereof is for a breathable fire bed provided in a center portion in the width direction of a pallet truck of a sintering machine. A pallet truck for a downward suction type sintering machine in which a non-breathable plate is provided on both sides, a bed ore is loaded on the non-breathable plate and the breathable fire bed, and a sintering raw material is further loaded on the top. In the pallet truck of the sintering machine, the pallet truck is provided with a step in which the upper surface of the non-breathable plate is lower than the height of the upper surface of the breathable fire bed. The means 2 has the step difference of 20.
The pallet truck of the sintering machine according to means 1, which is ˜30 mm. The means 3 is the pallet truck of the sintering machine according to the means 1 or 2, wherein the width of the non-permeable plate is 3 to 9% of the width of the permeable fire bed. The means 4 is the means 1 to
When loading bedding ore on the pallet trolley having the structure according to any one of 3 above, the bed ore to be loaded on the breathable fire bed and the bed ore to be loaded on the non-permeable plate This is a method for adjusting the air permeability of a pallet truck of a sintering machine, which adjusts the lap thickness to adjust the air permeability of the side portion of the pallet truck. The means 5 is
The method for adjusting the air permeability of a pallet truck of a sintering machine according to means 4, wherein the wrap thickness is 10 to 20 mm.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A pallet truck 15 of a sintering machine according to an embodiment of the present invention will be described below with reference to FIG. As shown in FIG. 1, a pallet truck 15 of a sintering machine according to an embodiment of the present invention has a breathable fire bed 1 in which a plurality of great bars (grates) 11 are arranged side by side in the widthwise central portion.
6 and a non-breathable plate 10 composed of a non-breathable flat plate on both sides thereof. And the upper surface position of the non-breathable plate 10 is 20 to 30 mm from the height of the upper surface position of the breathable fire bed 16.
The height is lowered to form the step Y. And this non-breathable plate 1
No. 0 and the breathable fire bed 16 are loaded with bed mat in a width direction of the pallet truck 15 with a substantially uniform layer thickness (30 to 40 mm), and then a sintering raw material is loaded. Thereby, the non-breathable plate 10
At the boundary portion 17 between the and the breathable fire bed 16, the step Y and the lap portion X (continuous bed deposit layer) corresponding to the layer thickness of the bed deposit layer 12 are formed.

In this state, when air is taken in from below the pallet truck 15, a shrinkage gap δ formed between the pallet side wall (sidewall) 13 and the sintering raw material layer 18 (formed by sintering sintering raw material is formed. Gap) and pallet side wall 13
The air that has flowed in from the upper surface of the sintering raw material layer 18 in the vicinity of does not pass through the non-breathable plate 10, flows in the direction of the arrow Z in the bed ore layer 12, and passes through the lap portion X of the bed ore layer 12 for air permeability. It flows out of the fire bed 16. As described above, since the lap portion X of the bed ore layer 12 serves as a passage for the suction air flowing in the arrow Z direction, the ventilation amount of the suction air flowing in the arrow Z direction changes according to the layer thickness of the lap portion X. To do. That is, in the present embodiment, the upper surface of the non-breathable plate 10 is made lower than the upper surface of the breathable fire bed 16 to form the step Y, so that the layer thickness of the lap portion X of the bed ore layer 12 is reduced. Thus, the air permeability in the vicinity of the pallet side wall 13 (in the vicinity of the shrinkage gap δ and the upper surface of the sintering raw material layer 18 of the pallet side wall 13) can be suppressed.
Then, it is preferable that the step Y is 20 to 30 mm.
This is because the bed ore bed 12 has a layer thickness of 30 to 4 as described above.
0 mm, the particle diameter of the bed ore is 10 to 20 mm, and the layer thickness of the lap portion X is 1 as shown in FIG.
If it is less than 0 mm, the air permeability is deteriorated, and it becomes difficult for the air to flow near the side wall of the pallet, so that the sintering reaction is hard to be promoted and an unsintered portion is generated. Therefore, the layer thickness of the lap portion X is 10
It is preferable that the step Y is 30 mm or less in order to make the thickness more than mm. Further, if the step Y is increased, the productivity of the sintered ore is affected and the layer thickness of the lap portion X is 20 mm.
If it exceeds, there will be almost no change in breathability, so the step Y
Is preferably 20 mm or more.

The width W ₁₀ of the non-breathable plate 10 is preferably 3 to 9% of the width W ₉ of the breathable fire bed 16.
This is 3 as shown in FIG. 4 (when the step Y is 20 mm).
If it is less than%, the effect of the non-breathable plate is small, and the excess air amount from the vicinity of the pallet side wall cannot be eliminated even if the step Y is provided, and the yield is reduced. On the other hand, if it exceeds 9%, it becomes difficult to secure the air volume necessary for firing near the side wall of the pallet, and unburned raw materials are produced to lower the yield.

Further, when the bed ore is charged on the pallet truck 15, the amount of the bed ore charged on the non-permeable plate 10 and the permeable fire bed 16 is adjusted to form the stepped portion. By controlling the layer thickness of the lap portion X of the floor laid ore layer 12, the air permeability of the side portion of the pallet truck 15 is adjusted. This is because it is necessary to adjust the air permeability in the vicinity of the pallet side wall 13 when the layer thickness of the sintering raw material layer 18 is changed to adjust the productivity. At this time, by adjusting the layer thickness of the floor laying ore layer 12 in the entire width direction of the pallet truck 15 or the layer thickness only on the non-breathable plate 10, the layer thickness of the lap portion X is controlled to achieve the target. The air permeability in the vicinity of the pallet side wall 13 can be ensured. However, when the layer thickness of the lap portion X exceeds 20 mm, ventilation in this portion becomes too good, and the effect of the step Y (ventilation suppression effect) disappears, and 10 mm
If it is less than the above, on the contrary to the above, ventilation in this portion is reduced, and it becomes difficult to secure the air volume necessary for firing, so the layer thickness of the lap portion X is set to 10 to 20 mm, within this range. It is preferable to adjust the layer thickness with.

[0010]

EXAMPLE An example of the present invention has a production capacity of 16000t.
/ Day, sintering pallet area: 600 m ² , pallet truck width: 5.5 m, downward suction blower capacity 2700 m ³
The description will be made in the case of being applied to a Dwightroid-type sintering machine of / min. In addition, the width W ₁₀ of the non-breathable plate 10 is set to 160 to 45.
0 mm, and the width W ₉ of the breathable fire bed 16 is 4.6 to 5.3.
m. In addition, the upper surface of the non-breathable plate 10 and the breathable fire bed 16
The step Y on the upper surface was set to 15 to 35 mm. Further, the layer thickness of the sintering raw material of the pallet truck 15 was 600 mm, the particle size of the bed ore was 10 to 20 mm, and the lap portion X was 5 to 25 mm. In order to measure the air permeability in the vicinity of the pallet side wall 13 and in the central portion, as shown in FIG. 5, the sintering raw material layer 18 after ignition was used.
A cylinder 14 having a diameter of 100 mm and a length of 500 mm was installed on the top, and the wind speed passing through the cylinder 14 was measured and evaluated. Table 1
The operation results of the example of the present invention and the comparative example are shown in FIG. In the operation, the step Y, the non-breathable plate width, the breathable fire bed width, and the lap portion X of the bedding ore layer were changed, and the air flow rate and the yield of the pallet side wall portion were compared and evaluated. Since the invention examples 1 to 4 were within the scope of the invention, a good product yield could be obtained.

[0011]

[Table 1]

Further, Comparative Examples 1 and 2 are Comparative Examples in Claim 2. In Comparative Example 1, the step Y is 15 mm, which is outside the lower limit of Claim 2, so that the wind speed on the side wall of the pallet is high and the yield is high. Reduced. In Comparative Example 2, the step difference was 35 mm, which was outside the upper limit of claim 2, so that the wind speed on the side wall of the pallet was low and the yield was reduced. Comparative examples 3 and 4 are comparative examples in claim 3, and in this comparative example 3, the non-breathable plate width is 1.9% of the breathable fire bed width, which is outside the lower limit of claim 3, and therefore the pallet side wall portion. The wind speed was high and the yield was reduced. In Comparative Example 4, the non-breathable plate width was 9.8% of the breathable fire bed width, which was outside the upper limit of claim 3, so the wind speed on the side wall of the pallet was low and the yield was reduced. Comparative Examples 5 and 6 are Comparative Examples in Claim 5, and in Comparative Example 5, the lap amount of the lap portion X was 5 mm, which was outside the lower limit of Claim 5, so the wind speed of the pallet side wall portion was reduced. Comparative Example 6 has a lap amount of 25
In mm, the upper limit of claim 5 was exceeded, so the wind velocity on the side wall of the pallet was high and the yield was reduced.

[0013]

As described above, according to the present invention, the ventilation near the side wall of the pallet is significantly suppressed, and the difference in air flow between the both end regions and the central region of the sintering raw material layer charged on the pallet is small. Therefore, it becomes possible to improve the yield of the sintered ore, and the effect in this field is great.

[Brief description of drawings]

FIG. 1 is a simplified sectional view of a pallet truck of a sintering machine according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an overall configuration of a Dwightroid (DL) sintering machine.

FIG. 3 is an explanatory diagram showing a relationship between an average wind speed and a step Y on a side wall portion of a pallet.

FIG. 4 is an explanatory diagram showing a relationship between a ratio of a non-breathable plate width and a breathable fire bed width and a yield.

FIG. 5 is a schematic diagram of a method for measuring the air flow rate on the side wall of the pallet.

[Explanation of symbols]

1: bedding mat, 2: bedding hopper, 3: pallet truck,
4: compounded raw material, 5: raw material hopper, 6: drum feeder, 7: charging device, 8: sintered raw material layer, 9: ignition furnace, 1
0: Non-breathable board, 11: Great bar (grate), 1
2: Bedbed ore layer, 13: Pallet side wall (sidewall), 14: Cylinder, 15: Pallet trolley, 16: Breathable fire bed, 17: Boundary part, 18: Sintering raw material layer, X: Wrapped bed orebed layer Part, Y: step, Z: direction of suction air flow

Claims (5)

[Claims] 1. A non-breathable plate is provided on both sides of a breathable fire bed provided in a center portion in the width direction of a pallet truck of a sintering machine, and a bed ore is loaded on the non-breathable board and the breathable fire bed. Further, in the pallet truck of the downward suction type sintering machine in which the sintering raw material is charged in the upper part, the upper surface position of the non-breathable plate is attached to the pallet carriage by the height of the upper surface position of the breathable fire bed. A pallet trolley for a sintering machine, which is characterized by providing a step lower than the height. 2. The pallet truck of the sintering machine according to claim 1, wherein the step is 20 to 30 mm. 3. The width of the non-breathable plate is 3 to 9% of the width of the breathable fire bed.
Alternatively, the pallet truck of the sintering machine described in 2. 4. A bedding ore that is charged on the breathable fire bed and a non-permeable plate when the bedding ore is charged on the pallet trolley according to any one of claims 1 to 3. The air permeability of the pallet truck of the sintering machine is adjusted by adjusting the wrap thickness of the bed ore charged in the pallet to adjust the air permeability of the side portion of the pallet truck. 5. The air permeability adjusting method for a pallet truck of a sintering machine according to claim 4, wherein the lap thickness is 10 to 20 mm.