Pallet sidewall, pallet sidewall renewal method, and sintered ore manufacturing device

Abstract

To provide a pallet side wall, etc., that reduce an air leak caused by a gap formed between side walls.SOLUTION: Pallet side walls are provided on both end parts in a crosswise direction of a pallet into which sintered ore is loaded. At least one end part in a travel direction of the pallet includes plural protrusions formed extending in a height direction and formed protruding in the travel direction. The plural protrusions are arrayed at intervals in the crosswise direction of the pallet.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to pallet sidewalls provided at both ends in the width direction of a pallet into which sintered ore is charged, a pallet sidewall renewal method, and a sintered ore manufacturing apparatus. [Background technology]

[0002] When producing sintered ore, raw materials are fed into a charging device and spread out on a cart called a pallet, and the surface layer is ignited in an ignition furnace. The pallet has a side wall to prevent the raw materials from spilling out.

[0003] The bottom of the pallet is connected to a main exhaust fan, allowing ventilation. The exhaust gases generated during the sintering of the raw materials are sucked under negative pressure by the main exhaust fan. Therefore, the sintering of the raw materials loaded on the pallet progresses from the top layer to the bottom layer.

[0004] The raw materials loaded onto the pallet are repeatedly heated and cooled. The sidewalls that come into contact with the raw materials are also made of cast iron, and therefore expand and contract with thermal changes. For this reason, a gap is provided between adjacent sidewalls in the direction of pallet travel to prevent the sidewalls from coming into contact with each other.

[0005] This gap between the sidewalls is one of the causes of air leakage. If air leakage occurs when negative pressure is sucked in by the main exhaust fan, the amount of air contributing to firing decreases, the firing speed drops, and the sintering productivity drops.

[0006] To address this issue, for example, Patent Document 1 discloses a method of attaching a seal plate to the end of the sidewall. The seal plate comes into contact with the end face of the sidewall and prevents gaps from forming due to deformation of the sidewall.

[0007] In Patent Document 2, sealing members are provided in grooves provided on the end faces of the sidewalls. The sealing members provided on adjacent pallets in the traveling direction come into contact with each other to close the gap between the sidewalls. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Utility Model Application Publication No. 5-8394 [Patent Document 2] Japanese Patent Application Publication No. 2020-180768 Summary of the Invention [Problem to be solved by the invention]

[0009] The seal plate in Patent Document 1 has a pin hole formed therein. The seal plate is attached to the sidewall via a guide pin inserted into the pin hole. When a gap occurs between the sidewalls, the seal plate rotates around the axis of the guide pin due to its own weight so as to close the gap.

[0010] However, with the seal plate of Patent Document 1, there is a risk that the seal plate will not rotate to the desired position due to dust getting caught in the guide pin, etc. This causes poor contact between the seal plate and the sidewall, resulting in a problem of air leakage from the gap between them.

[0011] Furthermore, in Patent Document 2, the contact between the sealing members causes a load to be transmitted to the sidewalls, which may cause the sidewalls to push against each other and crack when thermally expanded or contracted. Furthermore, the sealing members must be heat-resistant so that they can be used in the high-temperature environment of approximately 1400°C where the sintering raw materials are fired. Furthermore, at the end of the pallet where it moves along the endless track, gaps form between adjacent sealing members, which then return to a contacting state, so the contacting sealing members must be wear-resistant. There are currently no materials that possess the above-mentioned heat resistance and wear resistance while also maintaining elasticity even after long-term use.

[0012] Furthermore, in Patent Document 2, since the sidewalls come into contact with each other via the sealing member, if one sidewall collapses, there is a risk that the other adjacent sidewalls will also collapse. Furthermore, for repairs or other purposes, the pallet is lifted from above by a crane or the like and removed from the sintering machine. At that time, if the sealing plate remains attached, the working space becomes narrow, so there is a risk that the adjacent sidewalls will collapse when the pallet swings. To avoid this situation, the sealing plate must be removed before lifting, which complicates the work.

[0013] The present invention has been made in consideration of the above problems, and aims to provide a pallet sidewall or the like that reduces air leakage caused by gaps formed between the sidewalls. [Means for solving the problem]

[0014] In order to solve the above problems, the present invention has the following features.

[0015] [1] A pallet sidewall provided at both ends in the width direction of the pallet into which sintered ore is charged, At least one end of the pallet in the traveling direction has a plurality of protrusions formed to extend in the height direction and protrude along the traveling direction, The plurality of protrusions are arranged at intervals in the width direction of the pallet. [2] The sidewalls are provided at intervals from the sidewalls of adjacent pallets in the direction of travel of the pallet, The sidewall of a pallet described in [1], wherein the spacing between the multiple protrusions in the width direction of the pallet is 1.2 to 3.0 times the spacing between the sidewall and the sidewall of the other pallet. [3] the plurality of protrusions include a plurality of first protrusions formed to extend in a height direction, and a plurality of other protrusions formed to extend in a direction forming an angle with respect to the first protrusion, The sidewall of a pallet according to [1] or [2], wherein the other protrusions are arranged at intervals in the height direction. [4] removing at least one existing sidewall provided at both ends of the pallet in the width direction; and installing the pallet sidewall according to any one of [1] to [3] in the position of the removed sidewall. [5] A Dwight Lloyd type sintered ore manufacturing apparatus having a circulating pallet on which raw materials for sintered ore are charged, and an ignition furnace for sintering the raw materials charged on the pallet, The pallet has sidewalls provided at both ends in the width direction thereof, the sidewall has a plurality of protrusions formed at at least one end in the traveling direction of the pallet and protruding along the traveling direction, The sintered ore manufacturing apparatus, wherein the plurality of protrusions are arranged at intervals in the width direction of the pallet. [Effects of the Invention]

[0016] The sidewalls of the pallet according to the present invention have a plurality of protrusions formed at at least one end in the direction of travel of the pallet, protruding along the direction of travel. As a result, the protrusions obstruct the movement of wind in the gap between the sidewall located on the leading side in the direction of travel of the pallet and the sidewall located on the trailing side. Furthermore, the plurality of protrusions are arranged at intervals in the width direction of the pallet, which generates negative pressure in the gaps between the protrusions and creates wind vortices. This obstructs the movement of wind in the width direction of the pallet. In other words, by obstructing the movement of wind, it is possible to reduce wind leakage. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a configuration diagram of a sintered ore manufacturing apparatus. [Figure 2] FIG. 2 is a perspective view of the pallet of FIG. 1. [Figure 3] FIG. 10 is an explanatory diagram showing adjacent sidewalls in the traveling direction of the pallet. [Figure 4] FIG. 10 is an explanatory diagram showing a sidewall according to a modified example. [Figure 5] FIG. 10 is a perspective view of a pallet according to a second embodiment. [Figure 6] 10 is a graph showing the installation state of the convex portion and the relative amount of air leakage. [Figure 7] 10 is a graph showing the number of protrusions and the relative amount of air leakage. [Figure 8] FIG. 10 is an explanatory diagram showing the state of wind flowing through the gap between adjacent sidewalls. [Figure 9] FIG. 10 is an explanatory diagram showing the state of wind flowing through the gap between adjacent sidewalls. [Figure 10] FIG. 10 is an explanatory diagram showing the state of wind flowing through the gap between adjacent sidewalls. DETAILED DESCRIPTION OF THE INVENTION

[0018] (First embodiment) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the preferred embodiments thereof. Fig. 1 is a schematic diagram showing an example of a sintered ore manufacturing apparatus 100 for manufacturing sintered ore.

[0019] The sintered ore manufacturing apparatus 100 has a charging device 10 that stores raw materials for sintered ore (hereinafter also referred to as sintered raw materials), a sintering machine 20 that sinters the sintered raw materials supplied from the charging device, and a crusher 30 that crushes the sintered ore sintered by the sintering machine 20.

[0020] Examples of the components of the sinter raw material stored in the charging device 10 include iron-containing raw materials including various iron ores such as hematite and magnetite, CaO-containing raw materials including limestone and quicklime, MgO-containing raw materials including dolomite and refined nickel slag, and powdered coke. The iron-containing raw materials may also include dust generated within the steelworks, such as dust that is blown up within the steelworks. The sinter raw materials may also include return ore, which is fine sintered ore that does not meet a specified size.

[0021] The sintering machine 20 is, for example, a downward suction type Dwight Lloyd type sintering machine. The sintering machine 20 has an endless moving pallet 21 that receives sintering raw materials from a charging device 10 and transports the sintering raw materials in one direction (hereinafter also referred to as the traveling direction). The sintering machine 20 has an ignition furnace 22 that is provided above the pallet 21 and sinters the sintering raw materials, and a wind box 23 that is provided below the pallet 21 and generates an air current that flows from above to below.

[0022] The sintering raw materials stored in the charging device 10 are charged onto a pallet 21. The solid arrow indicates the direction of travel of the pallet 21. As shown in the figure, the pallet 21 is configured to be circulatively movable.

[0023] The sintering raw material loaded on the pallet 21 is adjusted in thickness by a cut gate (not shown) while being conveyed in the direction of travel of the pallet 21 , and is ignited by an ignition furnace 22 .

[0024] The dashed arrows in the figure indicate the direction of air flow. When air is sucked in by the wind box 23, an air current is generated that flows from above to below the pallet 21. As a result, the powdered coke and agglomerates, including anthracite, contained in the sintering raw materials are combusted, and the combustion and melting zone moves downward.

[0025] This sinters the sinter raw material to form a sinter cake. The sinter cake is crushed by a crusher 30 to form sintered ore. The sintered ore crushed by the crusher 30 is cooled by a cooler (not shown). The sintered ore cooled by the cooler is sieved by a screening device (not shown) having multiple sieves, and is separated into finished sintered ore of a predetermined particle size or larger and return ore. The finished sintered ore obtained in this manner is called sintered ore. The finished sintered ore is charged into a blast furnace as blast furnace raw material. Return ore that does not meet the specified size after being screened by the screening device can be reused as sintered raw material.

[0026] Figure 2 shows the structure of the pallet 21. As shown in Figure 2, the pallet 21 has a bottom 24 that extends left and right when viewed from the direction of travel DT, i.e., in the width direction DW of the pallet 21. The bottom 24 is formed so that the width direction DW of the pallet 21 is longer than the direction of travel DT of the pallet 21. The bottom 24 is formed in a grate shape by arranging grate bars 25 along the width direction DW of the pallet 21.

[0027] A pair of sidewalls 26 are provided on the bottom 24, extending upward from both ends of the pallet 21 in the width direction DW. The sidewalls 26 are plate-shaped members that extend in the short direction of the pallet 21 and in the height direction. The sidewalls 26 are provided on their inner surfaces with liners 27 that reduce wear due to contact with the sintering raw material.

[0028] The sidewall 26 has a plurality of protrusions 28 formed at at least one end in the traveling direction DT of the pallet 21 and protruding along the traveling direction DT. Each of the protrusions 28 is formed in a columnar shape. Each of the protrusions 28 is formed to extend in the height direction. Each of the protrusions 28 is arranged at intervals in the width direction DW of the pallet 21.

[0029] The sidewall 26 may be formed, for example, using cast iron, although the material is not particularly limited. The protrusion 28 may be formed, for example, by cutting the sidewall 26 or by using a mold for the sidewall 26, although the material is not particularly limited.

[0030] The pair of side walls 26 are formed so as to extend outward in the width direction DW of the pallet 21 as they extend upward.

[0031] Fig. 3 shows adjacent sidewalls in the traveling direction DT of the pallet 21. As shown in Fig. 3, a space SP1 is provided between the sidewall 26a provided in the leading position and the sidewall 26b provided in the trailing position in the traveling direction DT of the pallet 21.

[0032] In this embodiment, the protrusions 28 are formed to protrude in the traveling direction DT of the pallet 21. The protrusions 28 are provided in the width direction DW of the pallet 21 at intervals SP2.

[0033] The arrows in Figure 3 indicate the flow of wind. As shown in Figure 3, wind flows from the outside of the pallet 21 in the width direction DW toward the raw materials 11 on the inside. At this time, the wind collides with the convex portion 28, and negative pressure is created immediately thereafter. As a result, a vortex is generated immediately after the convex portion 28 in the direction of the wind's movement.

[0034] In this way, by providing the protrusions 28, the progress of the wind is hindered by the protrusions 28 in the space SP1 between the side walls 26a, 26b. Furthermore, the protrusions 28 generate negative pressure in the space SP2, generating a vortex. This hinders the progress of the wind in the width direction DW of the pallet 21. In other words, by hindering the progress of the wind, it is possible to reduce wind leakage.

[0035] The spacing SP2 between the multiple protrusions 28 in the width direction DW of the pallet 21 is preferably 1.2 to 3.0 times, and more preferably 1.5 to 2.5 times, the spacing SP1 between the leading sidewall 26a and the trailing sidewall 26b. By setting the spacing SP2 to 3.0 times or less the spacing SP1 between the sidewalls 26a, 26b, it is possible to generate the above-mentioned vortex in an appropriate manner.

[0036] The amount of protrusion of the convex portion 28 in the traveling direction DT of the pallet 21 is not particularly limited as long as it can generate the above-mentioned vortex, but for example, it may be about 1 / 4 of the spacing SP1, and preferably about 1 / 2 of the spacing SP1. By making the amount of protrusion of the convex portion 28 in the traveling direction DT of the pallet 21 shorter than the spacing SP1, it is possible to prevent the sidewalls from coming into contact with each other. Furthermore, by making the amount of protrusion about 1 / 4 of the spacing SP1, it is possible to appropriately generate vortices and reduce air leakage.

[0037] When replacing the sidewalls of the pallet described above, the following method for replacing the sidewalls of the pallet is used. First, at least one of the existing sidewalls on both ends of the pallet in the width direction is removed. Next, a new pallet sidewall is installed in the position of the removed sidewall.

[0038] (Variation) In the above embodiment, an example has been described in which the protrusion 28 is provided on the sidewall 26b located on the trailing side. The protrusion may be provided on both the sidewall 26b located on the trailing side and the sidewall 26a located on the leading side.

[0039] Fig. 4 is an explanatory diagram showing a sidewall according to a modified example. As shown in Fig. 4, the sidewall 26a located on the leading side has convex portions 28a arranged in the width direction DW of the pallet 21. The sidewall 26b located on the trailing side has convex portions 28b arranged in the width direction DW of the pallet 21. The convex portions 28a are provided so as to be positioned between the convex portions 28b in the width direction DW of the pallet 21.

[0040] In this way, even when the protrusions 28a, 28b are provided on the trailing side sidewall 26b and the leading sidewall 26a, it is possible to generate vortices by the protrusions 28a, 28b, as in the first embodiment, and therefore it is possible to reduce air leakage.

[0041] In the above modification, an example has been described in which one protrusion 28a is provided on the sidewall 26a located on the leading side. However, the manner in which the protrusion 28a is provided on the sidewall 26a located on the leading side is not limited to this, and multiple protrusions 28a may be arranged in the width direction DW of the pallet 21, as in the sidewall 26b located on the trailing side.

[0042] (Second embodiment) In the above-described embodiment, an example has been described in which the protrusions 28 are formed to extend in the height direction. The protrusions are not limited to this shape, and may be any shape that generates a vortex wind in the width direction DW of the pallet 21. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted.

[0043] Fig. 5 shows a sidewall 40 according to the second embodiment. As shown in Fig. 5, one protrusion 41 formed to extend in the height direction and another protrusion 42 formed to extend in a direction forming an angle with respect to the one protrusion 41 are formed on the sidewall 40.

[0044] The first protrusion 41 can be formed in the same manner as the protrusion 28 described in the first embodiment.

[0045] In this embodiment, the other protrusions 42 are formed to extend along the width direction DW of the pallet 21. That is, the one protrusion 41 and the other protrusions 42 are formed to intersect with each other. In this embodiment, the one protrusion 41 and the other protrusions 42 are formed so as to form a rectangular grid.

[0046] In this way, even when the first protrusion 41 and the second protrusion 42 are formed, it is possible to reduce air leakage, as in the first embodiment. In particular, by providing the second protrusion 42 on the sidewall 40, a vortex can be generated in the air flowing from above to below in the gap SP1 between the sidewalls 40. As a result, it is possible to enhance the effect of reducing air leakage. [Example]

[0047] (Effect of convex parts on fluid) A convex portion was provided on one of the adjacent sidewalls in the direction of travel of the pallet, and a fluid analysis was conducted when negative pressure suction was applied.

[0048] The spacing between the sidewalls was 4 mm. The protrusions had a protrusion amount of 2 mm in the direction of travel of the pallet, a width of 2 mm in the width direction of the pallet, and were formed along the height direction of the sidewalls. The protrusions were arranged at intervals of 8 mm in the width direction of the pallet. Example 1 was a sample in which protrusions were provided as in the first embodiment. Example 2 was a sample in which protrusions were arranged in a grid pattern as in the second embodiment. The other protrusions in Example 2 were arranged at intervals of 8 mm.

[0049] The amount of air leakage was measured when no convex portions were provided on the sidewalls. The amount of air leakage was also measured for Example 1 and Example 2. Figure 6 shows the relative amount of air leakage for Example 1 compared to the amount of air leakage when no convex portions were provided on the sidewalls, and for Example 2 compared to the amount of air leakage when no convex portions were provided on the sidewalls.

[0050] Fig. 6 shows the relative air leakage amounts for Example 1 and Example 2. As shown in Fig. 6, the provision of the convex portion reduces the air leakage amount. In particular, it was found that Example 2 has a greater reduction effect than Example 1 because it can reduce air leakage from above to below in the height direction of the sidewall.

[0051] (The effect of the spacing of the convex parts in the width direction of the pallet on the fluid) A sidewall was fabricated in the manner described in Example 1. The spacing between the convex portions of the sidewall in the width direction of the pallet was set to 4 mm (4 mm pitch), 8 mm (8 mm pitch), and 12 mm (12 mm pitch), and the amount of air leakage was calculated according to the number of convex portions. The results are shown in Figure 7.

[0052] As shown in FIG. 7, it was found that in all examples with a pitch of 4 mm, a pitch of 8 mm, and a pitch of 12 mm, the amount of air leakage decreased as the number of protrusions increased.

[0053] Figure 8 shows the behavior of wind flowing through the gap between sidewalls when the sidewalls are formed at a pitch of 4 mm. In Figure 8, velocity vectors are shown according to the shape of the arrows. Also, in Figure 8, the vectors are displayed as levels, with level 1 being the smallest vector and level 5 being the largest vector.

[0054] As shown in Figure 8, in the area where the convex portion is not provided, the air flow path is formed as if it were wider. At the position where the flow path is wider, a wind of level 1 moves in a circular shape. In other words, a wind vortex is generated in that area. In addition, the vector level on the sidewall side where the convex portion is formed is lower than that on the sidewall side where the convex portion is not formed.

[0055] Figure 9 shows the state of wind flowing through the gap between sidewalls when the sidewalls are formed at a pitch of 8 mm. In Figure 9, velocity vectors according to the shape of the arrows are shown, just like in Figure 8.

[0056] As shown in Figure 9, even with a pitch of 8 mm, wind at level 1 moves in a circular pattern at the position where the flow path widens. In other words, wind vortices are generated in that area. Furthermore, the vector level on the sidewall where the convex portion is formed is lower than that on the sidewall where the convex portion is not formed. Furthermore, the level on the sidewall where the convex portion is not formed is lower than that when the pitch is 4 mm.

[0057] Figure 10 shows the state of wind flowing through the gap between the sidewalls when the sidewalls are formed at a pitch of 12 mm. In Figure 10, velocity vectors according to the shape of the arrows are shown, just like in Figure 8.

[0058] As shown in Figure 10, even with a 12mm pitch, level 1 wind flows in a circular pattern at the location where the flow path widens. In other words, wind vortices are generated in that area. Also, unlike the 4mm and 8mm pitches, no vortices are formed on the inside of the pallet width in that area. With a 12mm pitch, there are areas in that area where such vortices cannot form, so the 12mm pitch is slightly less effective at reducing wind leakage than the 4mm and 8mm pitches.

[0059] The vector level on the sidewall where the convex portion is formed is lower than that on the sidewall where the convex portion is not formed, and the level on the sidewall where the convex portion is not formed is also lower than that in the case of a pitch of 8 mm. [Explanation of symbols]

[0060] 100 Sintered ore manufacturing equipment 10 Charging device 11 Raw materials 20 Sintering machine 30 Crusher 40 sidewall DT Pallet direction of travel DW Pallet width direction

Claims

1. A pallet sidewall provided at both ends in the width direction of the pallet into which sintered ore is charged, At least one end of the pallet in the traveling direction has a plurality of protrusions formed to extend in the height direction and protrude along the traveling direction, The plurality of protrusions are arranged at intervals in the width direction of the pallet.

2. The sidewalls are provided at intervals from the sidewalls of adjacent pallets in the direction of travel of the pallet, The sidewall of a pallet according to claim 1, wherein the spacing between the plurality of protrusions in the width direction of the pallet is 1.2 to 3.0 times the spacing between the sidewall and the sidewall of the other pallet.

3. the plurality of protrusions include a plurality of first protrusions formed to extend in a height direction and a plurality of other protrusions formed to extend in a direction forming an angle with respect to the first protrusion, The sidewall of a pallet according to claim 1 , wherein the other protrusions are provided at intervals in the height direction.

4. the plurality of protrusions include a plurality of first protrusions formed to extend in a height direction and a plurality of other protrusions formed to extend in a direction forming an angle with respect to the first protrusion, The sidewall of a pallet according to claim 2 , wherein the other protrusions are provided at intervals in the height direction.

5. removing at least one existing sidewall provided at both ends of the pallet in the width direction; and installing the pallet sidewall according to any one of claims 1 to 4 in place of the removed sidewall.

6. A Dwight Lloyd type sintered ore manufacturing apparatus having a circulating pallet on which raw materials for sintered ore are charged, and an ignition furnace for sintering the raw materials charged on the pallet, The pallet has sidewalls provided at both ends in the width direction thereof, the sidewall has a plurality of protrusions formed at at least one end in the traveling direction of the pallet and protruding along the traveling direction, The sintered ore manufacturing apparatus, wherein the plurality of protrusions are arranged at intervals in the width direction of the pallet.

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