JP2023087778A - Method for producing sintered ore and sintering machine - Google Patents

Abstract

To provide a sintered ore production method and apparatus capable of eliminating local heat shortage in a sintering raw material layer and suppressing a decrease in the yield of sintered ore by controlling the amount of gas fuel supplied in the width direction of a sintering machine.SOLUTION: In a sintered ore production method, a sintering raw material containing an iron-containing raw material and a coagulant is charged into a pallet by an ore feeder of a sintering machine to form a charged layer, different amounts of gas fuel are supplied to the charged layer from a gas fuel feeder in the width direction of the pallet, and after the sintering raw material is sintered to obtain a sintered cake, the sintered cake is crushed to form a sintered ore. The gas fuel feeder includes a plurality of gas fuel supply pipes having a plurality of gas fuel discharge nozzles and a plurality of current plates in the moving direction of the pallet. The gas fuel discharge nozzles are provided to discharge the gas fuel in a horizontal direction parallel to the upper surface of the charged layer and in a width direction. The inclination angle θ of the current plates is 5° or more and satisfies the following formula (1). tanθ≤(W/2-D1)/H (1)SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to a method for producing sintered ore, which is a raw material for blast furnaces, and a sintering machine.

Conventionally, in a sintering machine that produces sintered ore, the sintering raw material is charged into an endless movable pallet, and the sintering raw material layer (charging layer) formed by charging the pallet A sintered cake, which is the source of sintered ore, is produced by sintering raw materials for sintering by igniting and blowing (supplying) gaseous fuel.

In Patent Document 1, regarding the supply of gaseous fuel to the sintering raw material layer, gaseous fuel sucked from the surface of the sintering raw material layer on the downstream side of the ignition furnace that ignites the sintering raw material layer on the pallet is disclosed. A method of supplying uniformly across the width of the sintering machine is disclosed.

Japanese Patent No. 4735682

Here, in the gaseous fuel supply method disclosed in Patent Document 1, the design concept is aimed at blowing the gaseous fuel uniformly into the sintering raw material layer in the width direction of the sintering machine. Therefore, the gas is discharged horizontally from the fuel gas pipe, and after the gaseous fuel is uniformly diffused in the width direction of the sintering machine, it is sucked into the sintering raw material layer. Furthermore, from a safety point of view, the gaseous fuel supplied from the fuel gas pipe may be ejected at a flow velocity that causes a blow-out phenomenon.In this case, the flow velocity of the air flow around the fuel gas pipe is higher. Therefore, the gaseous fuel diffuses widely in the width direction before reaching the surface of the sintering raw material layer. Therefore, it is not possible to intentionally increase the supply of gaseous fuel to a portion of the sintering raw material layer that is partially lacking in heat, and there is a problem that the yield of the product is lowered.

The present invention has been made in view of such circumstances, and by making it possible to adjust the amount of gaseous fuel supplied in the width direction of the sintering machine, it is possible to eliminate the local heat shortage in the charged layer and sinter. An object of the present invention is to provide a method for producing sintered ore and a sintering machine capable of suppressing a decrease in the yield of ore.

The gist and configuration of the present invention for solving the above problems are as follows.
[1] A sintering raw material containing an iron-containing raw material and a condensing material is charged into an endless movable pallet in a sintering machine feeding device to form a charging layer, and is provided downstream of the sintering machine. The coagulant on the upper surface of the charging layer is ignited in the ignition furnace, and different amounts of gaseous fuel are supplied to the charging layer in the width direction of the pallet from a gaseous fuel supply device provided downstream of the ignition furnace. The sintering raw material is sintered by sintering the sintering raw material by sucking the air in the charged layer with an air box provided below the pallet, and burning the coagulant to form a sintered cake. A method for producing sintered ore by crushing cake to obtain sintered ore, wherein the gaseous fuel supply device includes a gaseous fuel supply pipe having a plurality of gaseous fuel discharge nozzles in the moving direction of the pallet, and a rectifier. The plurality of gaseous fuel supply pipes are provided at different positions in the width direction, and the gaseous fuel discharge nozzle discharges the gaseous fuel in a horizontal direction parallel to the upper surface. The rectifying plate is provided so as to discharge in the width direction, the rectifying plate is provided at a position within 150 mm in the discharge direction of the gaseous fuel from the gaseous fuel supply pipe, and the inclination angle θ of the rectifying plate is 5° or more. A method for producing sintered ore, wherein the following formula (1) is satisfied, and the straightening plate has a length of 50 mm or more in the vertical direction.
tan θ≦(W/2−D1)/H (1)
In the formula (1), θ is the inclination angle (°) of the straightening plate with respect to the normal to the upper surface, with the direction in which the upper end of the straightening plate inclines toward the gaseous fuel discharge nozzle as positive, and W is is the distance (m) between the gaseous fuel supply pipes adjacent in the width direction, D1 is the distance (m) between the gaseous fuel supply pipe and the straightening plate in the discharge direction, and H is the gaseous fuel supply Distance (m) from the tube to the top surface.
[2] The gaseous fuel supply device includes a cylindrical hood provided to surround the gaseous fuel supply pipe, and a length of 20 mm or more and 200 mm or less that is provided at the lower end of the hood and protrudes inside the hood. A leakage prevention plate and an end straightening plate provided between the hood and the gaseous fuel supply pipe are further provided, and the end straightening plate extends from the gaseous fuel supply pipe in the discharge direction of the gaseous fuel. provided at a position within 150 mm, the inclination angle φ of the end straightening plate is 5° or more and 30° or less and satisfies the following formula (2), and the length of the end straightening plate in the vertical direction is 50 mm The method for producing sintered ore according to claim 1, which is the above.
(L-D2-B)/(H-S) ≤ tanφ (2)
In the formula (2), φ is the inclination angle (°) of the end straightening plate, with the direction in which the upper end of the end straightening plate inclines toward the gaseous fuel discharge nozzle with respect to the normal to the upper surface as positive. where L is the distance (m) between the hood and the gaseous fuel supply pipe, D2 is the distance (m) between the gaseous fuel supply pipe and the end straightening plate in the discharge direction, and B is the above is the length (m) of the leak-proof plate, and S is the distance (m) between the leak-proof plate and the top surface;
[3] The sintering according to [1] or [2], wherein the amount of gaseous fuel supplied to both ends of the charging layer in the width direction is made larger than the average amount of gaseous fuel supply in the entire width direction. Ore production method.
[4] Identify the position of the charging layer in the width direction where the amount of heat during sintering is insufficient, and make the gaseous fuel supply amount to the position higher than the average gaseous fuel supply amount in the entire width direction. The method for producing a sintered ore according to any one of [1] to [3], wherein the sintered ore is increased.
[5] A feeder for supplying sintering raw material containing an iron-containing raw material and a coagulant, an endless movable pallet in which the sintering raw material is charged to form a charged layer, and the ore feeder an ignition furnace for igniting the coagulant on the upper surface of the charging layer; and a wind box provided below the pallet for sucking air in the charge layer, wherein the gaseous fuel supply device is used to move the pallet A plurality of gaseous fuel supply pipes having a plurality of gaseous fuel discharge nozzles in a direction and a plurality of rectifying plates, the plurality of gaseous fuel supply pipes being provided at different positions in the width direction, and the gaseous fuel discharge nozzles comprising: The gaseous fuel is discharged in the horizontal direction parallel to the upper surface and in the width direction, and the current plate is positioned within 150 mm from the gaseous fuel discharge nozzle in the gaseous fuel discharge direction. wherein the current plate has an inclination angle θ of 5° or more, satisfies the following formula (1), and has a length of 50 mm or more in the vertical direction of the current plate.
tan θ≦(W/2−D1)/H (1)
In the formula (1), θ is the inclination angle (°) of the straightening plate with respect to the normal to the upper surface, with the direction in which the upper end of the straightening plate inclines toward the gaseous fuel discharge nozzle as positive, and W is is the distance (m) between the gaseous fuel supply pipes adjacent in the width direction, D1 is the distance (m) between the gaseous fuel supply pipe and the straightening plate in the discharge direction, and H is the gaseous fuel supply Distance (m) from the tube to the top surface.
[6] The gaseous fuel supply device includes a cylindrical hood provided so as to surround the gaseous fuel supply pipe, and a length of 20 mm or more and 200 mm or less that is provided at the lower end of the hood and protrudes inside the hood. A leakage prevention plate and an end straightening plate provided between the hood and the gaseous fuel supply pipe are further provided, and the end straightening plate extends from the gaseous fuel supply pipe in the discharge direction of the gaseous fuel. provided at a position within 150 mm, the inclination angle φ of the end straightening plate is 5° or more and 30° or less so as to satisfy the following formula (2), and the length of the end straightening plate in the vertical direction is 50 mm or more. 6. The sintering machine of claim 5, wherein
(L-D2-B)/(H-S) ≤ tanφ (2)
In the formula (2), φ is the inclination angle (°) of the end straightening plate, with the direction in which the upper end of the end straightening plate inclines toward the gaseous fuel discharge nozzle with respect to the normal to the upper surface as positive. where L is the distance (m) between the hood and the gaseous fuel supply pipe, D2 is the distance (m) between the gaseous fuel supply pipe and the end straightening plate in the discharge direction, and B is the above is the length (m) of the leak-proof plate, and S is the distance (m) between the leak-proof plate and the top surface;

According to the present invention, it is possible to adjust the amount of gaseous fuel supplied in the width direction of the sintering machine. By adjusting the supply amount of , it is possible to eliminate the local heat shortage in the charging layer and suppress the decrease in the yield of sintered ore.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows an example of the manufacturing apparatus of a sintered ore. It is a cross-sectional schematic diagram of a gaseous fuel supply apparatus. It is a schematic diagram which shows the arrangement configuration of a gaseous fuel supply pipe and a straightening plate. It is a schematic diagram which shows the arrangement structure of the gaseous fuel supply pipe|tube and the edge part straightening plate in the width direction edge part. FIG. 4 shows the results of a yield study of cross-sectional areas of the loading layer; 4 is a graph showing the relationship between the coke ratio and the amount of shrinkage of the charging layer.

Hereinafter, the present invention will be described through embodiments of the present invention. FIG. 1 is a schematic diagram showing an example of a sintered ore manufacturing apparatus 10 capable of implementing the sintered ore manufacturing method according to the present embodiment. The iron-containing raw material 12 stored in the yard 11 is transported to the blending tank 22 by the transport conveyor 14 . Iron-bearing feedstock 12 includes various grades of iron ore and steel mill dust.

The raw material supply unit 20 includes a plurality of mixing tanks 22, 24, 25, 26, and 28. The iron-containing raw material 12 is stored in the mixing tank 22 . The CaO-containing raw material 16 containing limestone, quicklime, etc. is stored in the mixing tank 24 . MgO-containing raw materials 17 containing dolomite, refined nickel slag, etc. are stored in the mixing tank 25 . A coagulant 18 containing fine coke and anthracite crushed to a particle size of 1 mm or less using a rod mill is stored in the blending tank 26 . Return ore having a particle size of 5 mm or less (sintered ore undersized powder) that has become the undersized sintered ore is stored in the blending tank 28 .

A predetermined amount of each raw material is cut out from the blending tanks 22 to 28 of the raw material supply unit 20, and blended to form a sintering raw material. The raw material for sintering is transported to the drum mixer 36 by the transport conveyor 30 . The MgO-containing raw material 17 is an optional mixed raw material, and may or may not be mixed with the sintering raw material.

The sintering raw material conveyed to the drum mixer 36 is added with an appropriate amount of water 34 and charged into the drum mixer 36 to be granulated into pseudo-particles having an average particle size of 3.0 to 6.0 mm, for example. The granulated raw material for sintering is transported to the ore feeder 42 of the sintering machine 40 by the transport conveyor 38 . The drum mixer 36 is an example of a granulating device that granulates the raw material for sintering. A plurality of drum mixers 36 may be provided, and a pelletizer granulator may be used instead of the drum mixer 36 . Moreover, both the drum mixer 36 and the pelletizer granulator may be used, or a high-speed stirrer may be installed upstream of the drum mixer 36 to stir the raw material for sintering.

In the present embodiment, the average particle diameter of the pseudo-particles is the arithmetic mean particle diameter, Σ (Vi × di) (where Vi is the abundance ratio of particles in the i-th particle size range, and di is i It is a representative particle size in the second particle size range.).

The sintering machine 40 is, for example, a downward suction Dwight Lloyd sintering machine. The sintering machine 40 has an ore feeding device 42, an endlessly movable pallet 44, an ignition furnace 46, a gaseous fuel supply device 47, and a wind box 48 such as a wind box. The sintering raw material is loaded into a pallet 44 in the feeder 42 to form a charged layer of sintering raw material. Then, the pallet 44 on which the charged layer is formed moves to an ignition furnace 46 provided downstream of the ore feeder 42 . The coagulant 18 contained in the surface layer (upper surface) of the charge layer is ignited in the ignition furnace 46 . After that, while sucking air through the wind box 48 provided below the pallet 44, the gaseous fuel and oxygen-enriched air are sucked into the charging layer in the gaseous fuel supply device 47 provided downstream of the ignition furnace 46, Burning gaseous fuel and condensate 18 in the charging bed continue combustion in the charging bed to move the molten zone below the charging bed. The charge layer is thereby sintered to form a sinter cake. As the gaseous fuel, combustible gases such as blast furnace gas, coke oven gas, blast furnace/coke oven mixed gas, converter gas, natural gas, methane gas, ethane gas, propane gas, city gas, and shale gas may be used.

The machine length direction of the sintering machine 40 in the present embodiment is the same direction as the moving direction of the pallet 44, and the width direction of the sintering machine 40 is a direction perpendicular to the moving direction and is the same as the width direction of the pallet 44. in the same direction.

The sintered cake is crushed by a crusher 50, cooled by a cooler 60, and screened by a screening device 70. In this way, sintered ore having a particle size of more than 5 mm is produced and charged into the blast furnace 80 by the transfer conveyor 76 . On the other hand, the return ore 74 having a particle size of 5 mm or less sieved by the sieving device 70 is conveyed to the mixing tank 28 of the raw material supply section 20 by the conveyer 78 . The particle size of the sintered ore 72 and the particle size of the return ore 74 mean the particle size sieved by a sieve. It is a particle size, and a particle size of 5 mm or less is a particle size that is sieved under a sieve with an opening of 5 mm. Each value of the grain size of the sintered ore 72 and the return ore 74 is merely an example, and is not limited to this value.

Next, the configuration of the gaseous fuel supply device 47 will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view of the gaseous fuel supply device 47. As shown in FIG. In FIG. 2 , the horizontal direction of the drawing corresponds to the width direction of the sintering machine 40 and the pallet 44 . The depth direction of the drawing is the machine length direction of the sintering machine 40 and corresponds to the moving direction of the pallet 44 .

A gaseous fuel supply device 47 shown in FIG. As shown in FIG. 2, the gaseous fuel supply device 47 includes, for example, nine oxygen-enriched air supply pipes 1 and five gaseous fuel supply pipes 3 in the width direction of the sintering machine 40 and the pallet 44. and 31 shielding plates 2 are provided. These are provided in order of the gaseous fuel supply pipe 3, the shielding plate 2, and the oxygen-enriched air supply pipe 1 from the bottom to the top in the rectangular cylindrical hood 6. As shown in FIG. The nine oxygen-enriched air supply pipes 1 are provided with a plurality of oxygen-enriched air discharge nozzles at different positions in the machine length direction of the sintering machine 40 (moving direction of the pallet 44). The supply pipe 3 is also provided with a plurality of gaseous fuel discharge nozzles 3a at different positions in the machine length direction. Further, the gaseous fuel supply pipes 3 are provided at different positions in the width direction of the pallet 44 perpendicular to the machine length direction.

Oxygen-enriched air is discharged from each oxygen-enriched air discharge nozzle and supplied to the charging layer 4 . The gaseous fuel is discharged from each gaseous fuel discharge nozzle 3 a and supplied to the loading layer 4 . The upper layer of the charge layer 4 tends to be sintered at a lower temperature than the middle and lower layers, and the yield tends to decrease. In this regard, in the present embodiment, by supplying gaseous fuel or oxygen-enriched air to the charging layer 4, the temperature during sintering of the upper layer of the charging layer 4 can be increased. A decrease in the yield of the upper layer can be suppressed. In addition, the shield plate 2 prevents the gaseous fuel from rising and suppresses mixing of the oxygen-enriched air and the gaseous fuel in the upper portion (the space above the oxygen-enriched air supply pipe 1 in the hood 6). Even if the shield plate 2 is provided as shown in FIG. 2, gaseous fuel may flow to the upper part of the hood 6. A device (not shown) is preferably provided to constantly monitor whether gaseous fuel rises or not.

Although the configuration in which the gaseous fuel supply device 47 is provided with the oxygen-enriched air supply pipe 1 and the shield plate 2 has been described with reference to FIG. 2, the oxygen-enriched air supply pipe 1 and the shield plate 2 are not necessarily provided. good too. However, by providing the shield plate 2, the influence of the wind (air current) around the sintering machine 40 on the gaseous fuel is suppressed, and the scattering of the gaseous fuel to the outside of the hood 6 is suppressed. Preferably, the device 47 is provided with the shielding plate 2 . The gaseous fuel supply device 47 has a control device (not shown) that controls the amount of gaseous fuel supplied to each gaseous fuel supply pipe 3 . The amount of gaseous fuel supplied to each gaseous fuel supply pipe 3 is controlled by the control device.

Next, the configuration of the gaseous fuel supply pipe 3 and the current plate 5 arranged near the gaseous fuel supply pipe 3 will be described with reference to FIG. 3 . FIG. 3 is a schematic diagram showing the arrangement configuration of the gaseous fuel supply pipe 3 and the current plate 5. As shown in FIG. As shown in FIG. 3, the gaseous fuel discharged from the gaseous fuel discharge nozzle 3a of the gaseous fuel supply pipe 3 is directed substantially parallel (horizontal) to the upper surface of the charging layer 4 (see the arrow in the figure). , in the width direction of the sintering machine 40 and the pallet 44 . Then, the gaseous fuel collides with the rectifying plate 5 and is supplied to the divided supply areas on the upper surface of the charging layer 4 based on the inclination angle of the rectifying plate 5 at a flow rate that is individually adjusted. becomes.

It is preferable that the straightening plate 5 is provided at a position within 150 mm from the gaseous fuel supply pipe 3 in the gaseous fuel discharge direction with respect to the gaseous fuel discharge nozzle 3a. When the distance from the gaseous fuel supply pipe 3 exceeds 150 mm, the discharged gaseous fuel diffuses with other air sucked into the charge layer 4 before colliding with the current plate 5 and flows downward. This is because it becomes impossible to control the supply position of the gaseous fuel by the straightening plate 5 . Further, it is more preferable to provide the rectifying plate 5 at a position within 100 mm from the gaseous fuel supply pipe 3 . This is because the gaseous fuel discharged from the gaseous fuel discharge nozzle 3a can generally maintain its horizontal movement within a distance of 100 mm, so that the flow control by the current plate 5 can be performed accurately. Moreover, it is preferable that the length of the current plate 5 in the vertical direction is 50 mm or more. By setting the length of the straightening plate 5 in the vertical direction to 50 mm or more, the gaseous fuel can reliably collide with the straightening plate 5, and the supply position of the gaseous fuel can be controlled.

It is preferable that the inclination angle .theta. of the rectifying plate 5 shown in FIG. 3 is 5.degree.
tan θ≦(W/2−D1)/H (1)
Here, θ is the inclination angle (°) of the rectifying plate 5 with respect to the perpendicular line K to the upper surface of the charging layer 4, and the direction in which the upper end of the rectifying plate 5 inclines toward the gaseous fuel discharge nozzle 3a is positive. W is the distance (m) between the gaseous fuel supply pipes 3 adjacent in the width direction, D1 is the distance (m) between the gaseous fuel supply pipe 3 and the current plate 5 in the discharge direction of the gaseous fuel, and H is It is the distance (m) from the gaseous fuel supply pipe 3 to the upper surface of the charging layer 4 .

If the inclination angle θ of the straightening plate 5 is smaller than 5°, the gaseous fuel after colliding with the straightening plate 5 diffuses upward in the hood 6, causing a problem of gaseous fuel leakage. Therefore, by setting the inclination angle θ of the current plate 5 to 5° or more, the upward flow along the current plate 5 after colliding with the current plate 5 can be suppressed, and the air flows downward together with the sucked air. .

When θ is larger than the formula (1) (when the formula (1) is not satisfied), the region where the gaseous fuel is supplied between the gaseous fuel supply pipes 3 adjacent to each other in the width direction (upper surface of the charging layer 4) , and it becomes difficult to individually adjust the amount of gaseous fuel supplied to each supply area divided on the upper surface of the charging layer 4 . Therefore, by adopting a configuration that satisfies the formula (1), the gaseous fuel supply region on the upper surface of the charging layer 4 can be divided, and in addition, the amount of gaseous fuel supplied to the gaseous fuel supply pipe 3 can be controlled. This makes it possible to adjust the amount of gaseous fuel supplied to each divided supply area.

If the direction of the gaseous fuel discharge nozzle 3a is tilted without using the rectifying plate 5, the discharge flow rate will change according to the discharge flow rate, and the gaseous fuel will flow on the upper surface of the charging layer 4. When it reaches, it spreads widely in the width direction. On the other hand, when the straightening plate 5 is used, the gaseous fuel collides with the straightening plate 5 to reduce the momentum of the gaseous fuel, and the direction of the flow of the gaseous fuel is adjusted according to the inclination angle of the straightening plate 5. Therefore, it is possible to control the gaseous fuel flow even if the discharge flow rate changes.

Next, the configuration of the gaseous fuel supply pipe 3 and the end rectifying plate 7 at the widthwise end of the sintering machine 40 will be described with reference to FIG. FIG. 4 is a schematic diagram showing the arrangement configuration of the gaseous fuel supply pipe 3 and the end rectifying plate 7 at the end in the width direction. As shown in FIG. 4, the gaseous fuel supply pipe 3 provided closest to the inner wall surface of the hood 6 is in the direction of discharging the gaseous fuel toward the inner wall surface of the hood 6. An end straightening plate 7 is provided between the supply pipe 3 and the supply pipe 3 . At a position facing the end straightening plate 7 with the gaseous fuel supply pipe 3 interposed therebetween, the above-described straightening plate 5 is provided.

Here, from the configuration of the device that allows the pallet 44 to move in the aircraft length direction, as shown in FIG. , a gap S exists. Therefore, if the gaseous fuel is intentionally supplied toward the charged layer 4 at the end of the width direction of the pallet 44, the gaseous fuel diffuses when it collides with the surface of the charged layer 4, The gaseous fuel leaks from the gap S between the hood 6 and the pallet 44, making it impossible to supply the gaseous fuel effectively. Conventionally, from the viewpoint of safety, the gaseous fuel could not be directly supplied to the charge layer 4 at the widthwise end of the pallet 44, and the gaseous fuel existing in the other space in the widthwise direction could not be supplied to the widthwise end. Since sintering is performed by being slowly sucked into the charge layer 4 at the end portion in the width direction, the yield value as the final product is low in the charge layer 4 at the end portion in the width direction.

For this reason, in this embodiment, a leakage prevention plate 8 having a horizontal portion with a length of 20 mm or more and 200 mm or less protruding inside the hood 6 is provided at a position below the hood 6 . This prevents the gaseous fuel from leaking from the gap S between the hood 6 and the pallet 44, and enables direct supply of the gaseous fuel to the charge layer 4 at the end in the width direction. Here, if the length of the leakage prevention plate 8 is shorter than 20 mm, the leakage prevention effect is lost. If the length of the leakage prevention plate 8 is longer than 200 mm, the end portion of the charge layer 4 will be widely covered, and gaseous fuel cannot be efficiently supplied to the end portion of the charge layer 4 . The higher the installation position of the leak prevention plate 8 on the inner wall surface of the hood 6, the more difficult it becomes to satisfy the equation (2) described later. It is preferable to install it in the vicinity.

As shown in FIG. 4, even at the widthwise end of the sintering machine 40, the gaseous fuel discharged from the gaseous fuel discharge nozzle 3a of the gaseous fuel supply pipe 3 is substantially parallel (horizontal) to the upper surface of the charging layer 4. ) direction (see the arrow in the drawing), and is discharged in the width direction of the sintering machine 40 and the pallet 44 . Then, it collides with the end straightening plate 7 , and based on the inclination angle of the end straightening plate 7 , the flow of the gaseous fuel is controlled toward the upper surface of the leakage prevention plate 8 .

Like the straightening plate 5, the end straightening plate 7 is preferably provided at a position within 150 mm from the gaseous fuel supply pipe 3 in the gaseous fuel discharge direction with respect to the gaseous fuel discharge nozzle 3a. When the distance from the gaseous fuel supply pipe 3 exceeds 150 mm, the discharged gaseous fuel diffuses with other air sucked into the charging layer 4 before colliding with the end rectifying plate 7 and moves downward. This is because the flow will flow, and control of the supply position by the end straightening plate 7 will become impossible. Further, it is more preferable to provide the end rectifying plate 7 at a distance of 100 mm or less from the gaseous fuel supply pipe 3 . This is because the gaseous fuel discharged from the gaseous fuel discharge nozzle 3a can generally maintain its horizontal movement within a distance of 100 mm, so that the flow control by the end rectifying plate 7 can be performed accurately. Also, the length of the end rectifying plate 7 in the vertical direction is preferably 50 mm or more, like the rectifying plate 5 . By setting the vertical length of the end straightening plate 7 to 50 mm or more, the gaseous fuel can reliably collide with the end straightening plate 7, and the gaseous fuel supply position can be controlled.

The inclination angle φ of the end rectifying plate 7 preferably ranges from 5° to 30° and satisfies the following formula (2).
(L-D2-B)/(H-S) ≤ tanφ (2)
Here, φ is the inclination angle (° ), L is the distance (m) between the hood 6 and the gaseous fuel supply pipe 3, and D2 is the distance (m) between the gaseous fuel supply pipe 3 and the end straightening plate 7 in the discharge direction of the gaseous fuel. where B is the length (m) of the horizontal portion of the leakage prevention plate 8 and S is the distance (m) between the leakage prevention plate 8 and the upper surface of the charging layer 4 .

If the inclination angle φ of the end rectifying plate 7 is smaller than 5°, the gaseous fuel after colliding with the end rectifying plate 7 diffuses upward in the hood 6, causing a problem of gaseous fuel leakage. Therefore, by setting the inclination angle φ of the end straightening vanes 7 to 5° or more, it is possible to suppress the upward flow along the end straightening vanes 7 after colliding with the end straightening vanes 7, and the air is sucked. flows downward with the air.

If the inclination angle φ of the end rectifying plate 7 is larger than 30°, when the gaseous fuel collides with the wall surface of the hood 6, a flow along the wall surface is generated, causing an upward flow in the hood 6. Diffusion will occur, resulting in an ineffective supply of gaseous fuel. Therefore, by satisfying the expression (2), the gaseous fuel can be intentionally supplied to the upper surface of the leakage prevention plate 8 at the width end of the charge layer 4, and leakage of the gaseous fuel from the hood 6 can be prevented. .

As described above, in this embodiment, the gaseous fuel discharge nozzle 3a capable of discharging the gaseous fuel in the horizontal direction is provided, and the current plate 5 is provided at a position within 150 mm from the gaseous fuel supply pipe 3, By adopting a configuration that satisfies the above-described formula (1), it is possible to divide the gaseous fuel supply area for the supply of gaseous fuel to the upper surface of the charging layer 4, and select a specific supply area from a plurality of supply areas. gaseous fuel can be supplied.

Furthermore, by providing an end rectifying plate 7 at the end of the sintering machine 40 in the width direction and providing a leakage prevention plate 8 at the lower part of the inner wall surface of the hood 6 to satisfy the above-mentioned formula (2), Leakage of the gaseous fuel from the hood 6 can be prevented at the width direction end of the charging layer 4 .

Next, the yield of sintered ore when sintered ore is produced by a conventional sintering method without using straightening plate 5 or end straightening plate 7 will be described with reference to FIG. The numerical unit for the dimensional information shown in FIG. 5 is mm (millimeter). Fig. 5 shows the result of a sintered ore yield survey of a cross-sectional area divided into 3 rows and 10 columns in the cross-sectional direction from the upper layer to the lower layer for the charging layer 4 with a width direction of 3.8 m and a charging layer thickness of 570 mm. It is a figure which shows. A numerical value in each cross-sectional area is a yield value as a final product in the cross-sectional area.

As shown in FIG. 5, it can be seen that the yield of the upper layer of the charging layer 4 is lower than that of the lower layer, and that the yield of both ends of the pallet 44 is particularly low compared to the widthwise center of the pallet 44 . For this reason, when gaseous fuel is supplied to the charging layer 4 in order to improve the yield, if the gaseous fuel is uniformly supplied in the width direction based on the yield at the center in the width direction, the yield at both ends can be increased. cannot be raised sufficiently. On the other hand, if the gaseous fuel is uniformly supplied in the width direction based on the yield at both ends, the amount of gaseous fuel supplied to the central portion in the width direction becomes excessive, so the cost of the excess gaseous fuel increases. end up

On the other hand, in the sintered ore production method and the sintering machine according to the present embodiment, it is possible to divide the gaseous fuel supply region in the width direction of the charging layer 4 on the upper surface of the charging layer 4. A specific supply area can be selected from the supply areas and the amount of gaseous fuel supplied to the supply area can be adjusted. Therefore, with respect to the amount of gaseous fuel supplied in the width direction of the pallet 44 of the charging layer 4, the amount of gaseous fuel supplied to both ends in the width direction can be made larger than the average gaseous fuel supply amount of the whole. As a result, the yield of both ends in the width direction of the pallet 44 can be improved more than other regions, so that the yield of sintered ore can be improved while suppressing the excessive supply of gaseous fuel.

Next, the relationship between the coke ratio and the amount of contraction of the charging layer will be described with reference to FIG. FIG. 6 is a graph showing the relationship between the coke ratio and the amount of shrinkage of the charging layer. The coke ratio is the blending ratio (% by mass) of coke fine, which is the condensing material 18 contained in the raw material for sintering. The amount of shrinkage (mm) of the charging layer 4 is how much the upper surface position of the charging layer 4 after charging the sintering raw material into the pallet 44 to form the charging layer 4 has decreased after sintering. It is calculated from the difference between the top surface height of the charged layer 4 after formation and the top surface height of the charged layer 4 after sintering.

As shown in FIG. 6, it can be confirmed that the amount of shrinkage of the charging layer 4 increases as the coke ratio of the sintering raw material increases. Here, since the coke ratio of the sintering raw material indicates the amount of heat during sintering, this result shows that there is a correlation between the amount of shrinkage of the charging layer 4 due to sintering and the amount of heat during sintering. By measuring the amount of shrinkage of 4, it can be seen that the amount of heat during sintering can be obtained.

That is, a non-contact position measuring device is installed at the position immediately after the charge layer 4 is formed and at the end of the sintering machine (the position where the charge layer 4 is finished being sintered). By measuring the height of the upper surface of the charging layer 4 at the position of , and calculating the difference in the height of the upper surface of the charging layer 4 before and after sintering (the amount of shrinkage), the heat shortage occurs in the width direction of the charging layer 4 It becomes possible to identify the position. A laser displacement meter or a sonic range finder can be used as the non-contact position measuring device, but the measuring device is not limited to a specific measuring device as long as it is a measuring device capable of position measurement.

Therefore, in the method for producing sintered ore and the sintering machine according to the present embodiment, the amount of shrinkage after sintering of the charging layer 4 after sintering is measured, and the amount of heat during sintering is insufficient. A position in the width direction of the charging layer 4 may be specified, and the amount of gaseous fuel supplied to the position of the supply area corresponding to the position may be increased from the average gaseous fuel supply amount of the entire width direction.

Further, even if the amount of shrinkage of the charged layer 4 after sintering is not measured, if the positions where the heat is insufficient during sintering (for example, both ends in the width direction of the charged layer 4) are specified in advance. , the amount of gaseous fuel supplied to the heat-deficient locations of the charge layer 4 may be increased relative to the overall average gaseous fuel supply.

In this way, even if there is a position in the width direction of the pallet 44 where the amount of heat during sintering decreases due to fluctuations in the component concentration of the raw material for sintering, the position of the charge layer 4 where the amount of heat has decreased is identified, and the position is determined. By increasing the amount of gaseous fuel supplied to the supply area corresponding to , more than the other supply areas, the amount of heat can be compensated, and the decrease in productivity of sintered ore (decrease in yield) due to the decrease in the amount of heat can be suppressed.

EXAMPLES Hereinafter, examples in which the yield of sintered ore was examined using the method for producing sintered ore and the sintering machine according to the present embodiment will be described.

<Example 1>
In this embodiment, as shown in FIG. 2, the gaseous fuel supply pipe 3 is positioned 500 mm above the upper surface of the charging layer 4 in the width direction of the charging layer 4 having a width of 3.8 m and a layer thickness of 570 mm. Five of them were installed symmetrically at a pitch of 800 mm. City gas is used as gaseous fuel to be supplied, and 0.4 vol. %, and injected horizontally from the gaseous fuel discharge nozzle 3a of the gaseous fuel supply pipe 3 provided in the center in the width direction.

Further, five ultrasonic displacement gauges were installed at positions in the same width direction as the gaseous fuel supply pipe 3 before and after the gaseous fuel supply device 47 in the moving direction of the pallet 44 . Firing was performed under conditions in which the inclination angle θ of the rectifying plate 5, the distance D1 in the discharge direction, and the length were changed. The fired pallet was extracted, and the 1/3 portion in the layer height direction, which is the upper layer of the charging layer 4, was divided into 10 parts in the width direction, and the average yield at the two central portions was investigated. Table 1 shows installation conditions of the rectifying plate 5 . The average yield was 79% when the rectifying plate 5 was not installed.

In invention example 1, a straightening plate 5 having a length of 100 mm is installed at a position 100 mm away from the gaseous fuel supply pipe 3 at an inclination angle of θ = 20°, so that the city gas is directed to the center 2 directly below the gaseous fuel supply pipe 3. We were able to supply several areas, resulting in a 2% increase in average yield for those areas.

In Comparative Example 1, since the distance between the rectifying plate 5 and the gaseous fuel supply pipe 3 was as large as 300 mm, city gas could not be effectively supplied to the central two areas. For this reason, the average yield in this range is the same as when the current plate 5 is not provided, and the average yield could not be improved. In Comparative Example 2, since the inclination angle θ of the straightening plate 5 was set to 0°, city gas leaked upward, and the supply of city gas was stopped from the viewpoint of safety. In Comparative Example 3, since the inclination angle θ of the rectifying plate 5 was set to 60°, the aforementioned formula (1) was not satisfied, and town gas could not be effectively supplied to the central two areas. For this reason, the average yield in this range is the same as when the current plate 5 is not provided, and the average yield could not be improved. In Comparative Example 4, since the straightening plate 5 having a length of 40 mm was used, city gas could not be effectively supplied to the central two areas. For this reason, the average yield in this range is the same as when the current plate 5 is not provided, and the average yield could not be improved. Comparative Example 5 is the result when the current plate 5 is not installed, and the average yield was 79%.

<Example 2>
Next, all of the gaseous fuel discharge nozzles 3a of the gaseous fuel supply pipe 3, including the charged layers 4 at both ends in the width direction, were ejected in the horizontal direction, and the straightening plate 5 and the end straightening plate 7 were also installed. Table 2 shows the conditions and results of the end current plate 7 and the leakage prevention plate 8. The straightening plate 5 was configured to have a length of 60 mm, and was installed at a position 50 mm away from the gaseous fuel supply pipe 3 with an inclination angle θ of 30°. In addition, when the city gas is not supplied to the ends of the charging layer 4 in the width direction, a portion of 300 mm from both ends in the width direction, which is the upper layer of the charging layer 4, in the height direction The yield of the 1/3 portion was 67%.

In invention example 2, the end straightening plate 7 having a length of 150 mm was installed at a position 80 mm away from the gaseous fuel supply pipe 3 with an inclination angle φ of 20°. At a height of 100 mm from the upper surface of the charging layer 4, a leakage prevention plate 8 with a horizontal portion of 100 mm long is installed. City gas could be supplied to the edge of layer 4, and the yield improved to 75%.

In Reference Example 1, since the inclination angle φ of the end rectifying plate 7 is set to 0°, the city gas diffuses upward and through the gap between the pallet 44 and the hood 6, and the supply of city gas is stopped from the viewpoint of safety. bottom. In Reference Example 2, since the inclination angle φ of the end rectifying plate 7 was set to 45°, the city gas diffused upward, and the city gas supply was stopped. In Reference Example 3, since the end rectifying plate 7 was installed at a position 200 mm from the gaseous fuel supply pipe 3, the city gas flow control could not be performed, and the city gas diffused upward, causing the city gas to be supplied. was discontinued. In Reference Example 4, since the length of the end rectifying plate 7 was set to 40 mm, the city gas flow could not be controlled, and part of the city gas diffused upward, so the supply of city gas was stopped. In Reference Example 5, since the length of the leakage prevention plate 8 was set to 10 mm, city gas leaked from the gap between the pallet 44 and the hood 6, and the supply of city gas was stopped. In Reference Example 6, since the length of the horizontal portion of the leakage prevention plate 8 was set to 250 mm, city gas was not effectively supplied to the ends of the charge layer 4 in the width direction, resulting in a yield of 69%. In Reference Example 7, since the leakage prevention plate 8 was installed at a position 200 mm from the upper surface of the charging layer 4, city gas leaked from the gap between the pallet 44 and the hood 6, and the supply of city gas was stopped.

From the above results, the length in the vertical direction is 50 mm or more, the distance from the gas fuel supply pipe is within 150 mm, and the rectifying plate 5 is provided so as to satisfy the above-described formula (1). can be selectively supplied to a specific range, and the yield of the range can be improved. Furthermore, by providing an end rectifying plate 7 at the end of the sintering machine 40 in the width direction and providing a leakage prevention plate 8 at the lower part of the inner wall surface of the hood 6 to satisfy the above-mentioned formula (2), It was confirmed that the gaseous fuel could be supplied while preventing gaseous fuel from leaking from the hood 6 at the width direction end of the charging layer 4, and the yield in the range could be improved.

REFERENCE SIGNS LIST 1 Oxygen-enriched air supply pipe 2 Shield plate 3 Gaseous fuel supply pipe 3a Gaseous fuel discharge nozzle 4 Charging layer 5 Straightening plate 6 Hood 7 End straightening plate 8 Leakage prevention plate 10 Production equipment for sintered ore 11 Yard 12 Iron content Raw materials 14, 30, 38, 76, 78 Conveyor 16 CaO-containing raw material 17 MgO-containing raw material 18 Coagulant 20 Raw material supply part 22, 24, 25, 26, 28 Mixing tank 34 Water 36 Drum mixer 40 Sintering machine 42 Supply Device 44 pallet 46 ignition furnace 47 gaseous fuel supply device 48 wind box 50 crusher 60 cooler 70 screening device 72 sintered ore 74 return ore 80 blast furnace D1 distance between gaseous fuel supply pipe and straightening plate D2 gaseous fuel supply pipe and Distance from end straightening plate θ Inclination angle of straightening plate with respect to normal to top surface of charging layer φ Inclination angle of end straightening plate with respect to normal to upper surface of charging layer H Above top of charging layer from gaseous fuel supply pipe Distance to the surface W Distance between gaseous fuel supply pipes adjacent in the width direction K Vertical line to the upper surface of the charged layer B Length of the horizontal part of the leakage prevention plate S Gap

Claims (6)

forming a charging layer by charging a sintering raw material containing an iron-containing raw material and a condensate into an endless movable pallet by a feeding device of a sintering machine;
igniting the condensate on the upper surface of the charging layer in an ignition furnace provided downstream of the feeder;
supplying different amounts of gaseous fuel to the charging layer in the width direction of the pallet from a gaseous fuel supply device provided downstream of the ignition furnace;
Air in the charge layer is sucked by an air box provided below the pallet, and the coagulant is burned to sinter the sintering raw material into a sintered cake, and then the sintered cake is A method for producing sintered ore by crushing to make sintered ore,
The gaseous fuel supply device has a plurality of gaseous fuel supply pipes having a plurality of gaseous fuel discharge nozzles in the moving direction of the pallet, and a plurality of straightening plates,
The plurality of gaseous fuel supply pipes are provided at different positions in the width direction,
The gaseous fuel discharge nozzle is provided to discharge the gaseous fuel in a horizontal direction parallel to the upper surface and in the width direction,
The rectifying plate is provided at a position within 150 mm from the gaseous fuel supply pipe in the discharge direction of the gaseous fuel,
A method for producing a sintered ore, wherein the current plate has an inclination angle θ of 5° or more, satisfies the following formula (1), and has a length of 50 mm or more in the vertical direction of the current plate.
tan θ≦(W/2−D1)/H (1)
In the formula (1), θ is the inclination angle (°) of the straightening plate with respect to the normal to the upper surface, with the direction in which the upper end of the straightening plate inclines toward the gaseous fuel discharge nozzle as positive, and W is is the distance (m) between the gaseous fuel supply pipes adjacent in the width direction, D1 is the distance (m) between the gaseous fuel supply pipe and the straightening plate in the discharge direction, and H is the gaseous fuel supply Distance (m) from the tube to the top surface. The gaseous fuel supply device includes a cylindrical hood provided so as to surround the gaseous fuel supply pipe, and a leakage prevention plate provided at the lower end of the hood and having a length of 20 mm or more and 200 mm or less protruding inside the hood. and an end straightening plate provided between the hood and the gaseous fuel supply pipe,
The end straightening plate is provided at a position within 150 mm from the gaseous fuel supply pipe in the gaseous fuel discharge direction,
2. The end straightening plate according to claim 1, wherein the inclination angle φ of the end straightening plate is 5° or more and 30° or less, satisfying the following formula (2), and the vertical length of the end straightening plate is 50 mm or more. A method for producing the described sintered ore.
(L-D2-B)/(H-S) ≤ tanφ (2)
In the formula (2), φ is the inclination angle (°) of the end straightening plate, with the direction in which the upper end of the end straightening plate inclines toward the gaseous fuel discharge nozzle with respect to the normal to the upper surface as positive. where L is the distance (m) between the hood and the gaseous fuel supply pipe, D2 is the distance (m) between the gaseous fuel supply pipe and the end straightening plate in the discharge direction, and B is the above is the length (m) of the leak-proof plate, and S is the distance (m) between the leak-proof plate and the top surface; The production of sintered ore according to claim 1 or 2, wherein the gaseous fuel supply amount to both ends of the charging layer in the width direction is increased more than the overall average gaseous fuel supply amount in the width direction. Method. Identifying the position of the charging layer in the width direction where the amount of heat during sintering is insufficient, and increasing the gaseous fuel supply amount to the position above the average gaseous fuel supply amount in the entire width direction; The method for producing sintered ore according to any one of claims 1 to 3. a feeder for supplying a sintering raw material comprising an iron-bearing raw material and a condensate;
an endless movable pallet on which the sintering raw material is charged to form a charging layer;
an ignition furnace provided downstream of the feeder for igniting the condensate on the upper surface of the charging layer;
a gaseous fuel supply device provided on the downstream side of the ignition furnace and supplying different amounts of gaseous fuel to the charging layer in the width direction of the pallet;
a wind box provided below the pallet for sucking air in the charging bed;
A sintering machine having
The gaseous fuel supply device has a plurality of gaseous fuel supply pipes having a plurality of gaseous fuel discharge nozzles in the moving direction of the pallet, and a plurality of straightening plates,
The plurality of gaseous fuel supply pipes are provided at different positions in the width direction,
The gaseous fuel discharge nozzle is provided to discharge the gaseous fuel in a horizontal direction parallel to the upper surface and in the width direction,
The rectifying plate is provided at a position within 150 mm in the gaseous fuel discharge direction from the gaseous fuel discharge nozzle,
A sintering machine, wherein the current plate has an inclination angle θ of 5° or more, satisfies the following formula (1), and has a length of 50 mm or more in the vertical direction of the current plate.
tan θ≦(W/2−D1)/H (1)
In the formula (1), θ is the inclination angle (°) of the straightening plate with respect to the normal to the upper surface, with the direction in which the upper end of the straightening plate inclines toward the gaseous fuel discharge nozzle as positive, and W is is the distance (m) between the gaseous fuel supply pipes adjacent in the width direction, D1 is the distance (m) between the gaseous fuel supply pipe and the straightening plate in the discharge direction, and H is the gaseous fuel supply Distance (m) from the tube to the top surface. The gaseous fuel supply device includes a cylindrical hood provided so as to surround the gaseous fuel supply pipe, and a leakage prevention plate provided at the lower end of the hood and having a length of 20 mm or more and 200 mm or less protruding inside the hood. and an end straightening plate provided between the hood and the gaseous fuel supply pipe,
The end straightening plate is provided at a position within 150 mm from the gaseous fuel supply pipe in the gaseous fuel discharge direction,
6. The end straightening plate according to claim 5, wherein the inclination angle φ of the end straightening plate is 5° or more and 30° or less to satisfy the following formula (2), and the length of the end straightening plate in the vertical direction is 50 mm or more. sintering machine.
(L-D2-B)/(H-S) ≤ tanφ (2)
In the formula (2), φ is the inclination angle (°) of the end straightening plate, with the direction in which the upper end of the end straightening plate inclines toward the gaseous fuel discharge nozzle with respect to the normal to the upper surface as positive. where L is the distance (m) between the hood and the gaseous fuel supply pipe, D2 is the distance (m) between the gaseous fuel supply pipe and the end straightening plate in the discharge direction, and B is the above is the length (m) of the leak-proof plate, and S is the distance (m) between the leak-proof plate and the top surface;

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