JP5408180B2 - Raw material charging equipment for sintering machine - Google Patents

Description

  The present invention relates to a raw material charging apparatus for charging a raw material for sintering into a sintering machine for continuously producing sintered ore.

The sintered ore used as a blast furnace raw material is generally produced by the following method.
The granulated raw material for sintering is continuously supplied from the hopper onto the pallet of the sintering machine with a predetermined layer thickness, for example, a layer thickness of about 500 to 700 mm. Next, the carbon material in the surface layer is ignited in an ignition furnace, and the carbon material is burned while forcibly sucking air downward. Sintered ore raw material is sintered and agglomerated by the combustion heat generated during combustion. The “sintered cake” thus fired is crushed and cooled. After cooling, the particles are sized and 3-5 mm or more particles that satisfy the quality standards are charged into the blast furnace as “sintered ore products”. A quality rejected product and a powder sintered ore of 3 to 5 mm or less generated in the crushing / sizing process are used again as a raw material for sintering as a return ore.

  The quality of the sintered ore used as the raw material for the blast furnace produced in this way has a great influence on the stability of the unloading state during the operation of the blast furnace, the ventilation / liquid permeability, the reduction efficiency, the high temperature property, and the like. Accordingly, high quality is required for the sintered ore, strict quality control is performed, and improvement of the product yield of the sintered ore is required to reduce the manufacturing cost.

  One of the most important conditions for maintaining high quality, maintaining high product yield, reducing manufacturing costs, and improving productivity for the above-mentioned sintered ore is the firing to be charged into the sintering machine pallet. It is to appropriately adjust both the in-layer particle size distribution and the component distribution of the binding raw material. By appropriately adjusting both the particle size distribution and the component distribution in the layer, the air permeability in the raw material layer having a height of about 500 to 700 mm is secured to improve the combustion of the carbonaceous material, and by the heat of combustion. It becomes possible to appropriately control the melting and sintering reaction of the sinter raw material. Therefore, conventionally, many raw material charging techniques for adjusting the in-layer particle size distribution and component distribution of the sintering raw material charged in the pallet have been proposed.

  For example, Patent Document 1 proposes a raw material charging apparatus as shown in FIG. The sintering raw material 3 is sent out from the hopper 1 by the roll feeder 2 and falls. The dropped sintering raw material 3 slides down the flat chute 4 that is inclined downwardly facing the roll feeder 2. A plurality of ropes or rods 5 are arranged in a width direction of the sintering machine pallet 6 at a predetermined pitch on a substantially extended line below the flat chute 4 so that a plurality of slit-like gaps 7 are formed. The sintering raw material sliding down falls onto the sintering machine pallet 6 from the plurality of slit-like gaps 7 to form a raw material layer 8 having a predetermined thickness. The downward inclination direction of the particle size segregation charging mechanism 9 which is a structure in which the slits 7 are formed with a plurality of the predetermined pitches is the moving direction of the sintering machine pallet 6 (the direction of the arrow x in FIG. 1). ). The slit-like gap 7 is narrow on the upper plate-like chute 4 side and wide on the lower sintering machine pallet 6 side. Thus, the particle size distribution of the raw material for sintering inside the raw material layer 8 charged in the pallet 6 can be adjusted so that coarse particles are deposited in the lower layer portion and fine particles are deposited in the upper layer portion (hereinafter referred to as the preceding). Technology 1).

  As another example, Patent Document 2 proposes a raw material charging apparatus as shown in FIG. The sintering raw material 3 is sent out from the hopper 1 by the roll feeder 2 and falls. The dropped sintering raw material is received by the drum feeder 10 that is provided below the roll feeder 2 and rotates in opposition to the falling direction of the sintering raw material. A plurality of rods or ropes 5 are arranged at a predetermined pitch in the width direction of the sintering machine pallet 6 on a curved surface that is inclined downward from the front surface of the drum feeder 10 and gently curved downward. A gap 7 is formed. The raw material for sintering whose dropping speed is reduced by the drum feeder 10 falls onto the sintering machine pallet 6 from the plurality of slit-like gaps 7 to form a raw material layer 8 having a predetermined thickness. The downward inclination direction of the particle size segregation charging mechanism 9 which is a structure having a plurality of the above-mentioned predetermined pitches and formed with slit-like gaps 7 is the moving direction of the sintering machine pallet 6 (the direction of the arrow x in FIG. 2). ). The slit-shaped gap 7 is narrow on the upper drum feeder 10 side and wide on the lower sintering machine pallet 6 side. Thus, the particle size distribution of the raw material for sintering inside the raw material layer 8 charged in the pallet 6 can be adjusted so that coarse particles are deposited in the lower layer portion and fine particles are deposited in the upper layer portion (hereinafter referred to as the preceding). Technology 2).

  As described above, according to the prior arts 1 and 2, as for the particle size of the raw material for sintering inside the raw material layer 8 charged in the sintering machine pallet 6, the lower layer is coarse and the upper layer is fine. Can be formed into a particle size distribution in which they are deposited. However, regarding the adjustment of the distribution of the components in the raw material layer 8, the raw material charging technique to the sintering machine pallet 6 according to the prior art such as the prior art 1 and the prior art 2 described above, the composition of the raw material for sintering It is not possible to adjust the distribution in the layer of components, for example, carbonaceous materials such as powdered coke that is a solid fuel and CaO that is a slag component.

  Further, in the raw material supply device in which the chute described in Patent Document 2 is continuously curved, the avalanche phenomenon can be prevented, but it is difficult to balance the curvature of the particle velocity and the rod arrangement curve, The problem of insufficient classification and the problem that all particles fall from between the rods before reaching the end of the chute occur.

Japanese Utility Model Publication No. 3-43599 JP-A-8-311568

  The purpose of this invention is to improve the controllability of the component distribution in addition to the particle size distribution in the raw material layer of the sintering machine pallet, and to achieve high quality, high yield and high productivity. It is to provide a raw material charging apparatus to a machine.

  In order to achieve the above object, the present invention provides a raw material supply mechanism for supplying a raw material for sintering to a pallet, an upper end thereof being positioned in the vicinity of the raw material supply mechanism, and a lower end thereof being above the pallet. Provided is a raw material charging device for a sintering machine, which is located and includes a chute that is inclined in a direction opposite to the moving direction of the pallet.

  The chute is composed of a plurality of rods arranged in parallel at a predetermined interval from the upper end to the lower end in the width direction of the pallet. In the upper part of the chute, the vertical projection gap between the plurality of rods in the area where the falling raw material collides is substantially constant.

These are the general | schematic vertical sectional views which show an example of the raw material charging device to the conventional sintering machine. These are figures which show typically the slit-shaped clearance gap in the segregation charging mechanism of the raw material charging device of Fig.1 (a). These are the general | schematic vertical sectional views which show the other example of the raw material charging device to the conventional sintering machine. These are vertical sectional views showing the raw material charging apparatus in the first embodiment. These are front views which show the chute | shoot in the raw material charging device in 1st Embodiment. These are the sectional views on the AA line of FIG. These are vertical sectional views showing the raw material charging apparatus in the second embodiment. These are the vertical sectional views which show the raw material supply apparatus in 3rd Embodiment. These are the graphs which show the vertical projection gap | interval between adjacent rods in the chute | shoot in this embodiment. These are the graphs which show the distance between rod centers between adjacent rods in the chute in this embodiment. These are the graphs which show the shape curve of the chute | shoot of the Example in this embodiment. These are the graphs which show the shape curve of the chute | shoot of the comparative example in this embodiment. These are the graphs which compared the average particle diameter in the raw material layer in this embodiment, and the ratio of C with the Example and the comparative example. These are the graphs which compared the ratio of CaO in the raw material layer in this embodiment with an Example and a comparative example.

  The present inventors have found that the projection gap in the vertical direction of the rod gap in the area where the falling raw material particles collide with the chute affects the classification effect of the raw material particles, and in the vertical direction of the rod gap. By making the projection gap of the above constant, among the raw material particles, coarse raw materials having a predetermined particle diameter or more were prevented from penetrating the rod. That is, the present invention provides a raw material supply mechanism for supplying raw materials to a pallet, and an upper end of the raw material supply mechanism that is positioned in the vicinity of the raw material supply mechanism, and a lower end of the raw material supply mechanism that is positioned above the pallet. In the raw material charging device of a sintering machine comprising a chute that is inclined in the direction opposite to the chute, the chute is spaced apart from each other in the width direction of the pallet from its upper end to its lower end. It consists of a plurality of rods arranged in parallel, and in the upper part of the chute, the vertical projection gap between the plurality of rods in the area where the falling raw material particles collide is constant. The above-mentioned problem was solved by the raw material charging apparatus.

  According to the present invention, in the raw material layer on the pallet, the particles falling from the upper part of the chute can be selectively limited to fine particles, so that a large particle size segregation can be obtained, which in turn improves the sintering yield and the production rate. can do. Here, the chute may be formed in a straight line shape or a planar shape. The rod also includes a linear member such as a wire.

  Further, the present invention is characterized in that the chute is curved in a concave shape from its upper end toward its lower end.

  The raw material charging apparatus in which the conventional chute is formed linearly has the following problems. The raw material slides down on a linear chute inclined at a predetermined angle, and is supplied into the pallet. For this reason, the impact when the raw material falls on the pallet and the angle of repose of the raw material increase, an avalanche phenomenon occurs in the raw material layer, and a fault occurs in the raw material layer. As a result, the grain size segregation in the layer direction of the raw material and the accompanying C and CaO distribution in the raw material layer become non-uniform. In addition, uneven ventilation occurs in the fault caused by the avalanche phenomenon, and the product yield decreases. In addition, the downhill speed of the particles sliding down on the chute becomes too fast, and the classification effect on the chute is low. According to the present invention, by forming a chute composed of a plurality of rods into a gentle concave surface, it is possible to alleviate the drop impact of the raw material at the time of dropping and prevent the avalanche phenomenon. In addition, the raw material can be further classified into coarse particles and fine particles to obtain an accurate particle size segregation in the pallet.

  Also, when arranging the rods in a concave screen shape, if the distance between the centers of adjacent rods is made constant from the upper end of the chute to the lower end, the vertical projection gap between the rods will increase from the upper end of the chute to the lower end. . The vertical projection gap between the rods increases similarly when the distance between the centers of the rods is increased uniformly unless the distance between the centers of the rods is shortened in the middle from the upper end to the lower end. When the vertical projection gap between the rods becomes longer from the upper part toward the lower part, the coarse raw material also passes through the gap in the area where most of the particles collide, and the classification effect for each particle diameter is lost. According to the present invention, even when the chute is curved in a concave shape, the projection gap in the vertical direction between the plurality of rods in the area where the falling raw material particles collide is made constant. Thus, it is possible to prevent a coarse raw material having a certain particle diameter or more from falling through the rod gap.

  Further, the present invention is characterized in that at least part of the rod interval (distance between the centers of adjacent rods) of the section is made smaller than the rod interval on the lower end side of the section.

  According to the present invention, the rod interval is larger than the rod interval of the above-mentioned region on the lower end side from the region arranged so that the projection interval in the vertical direction is constant. Since the coarse raw material falls from the gap between the rods at the lower part of the chute, the particle size segregation can be increased.

  Further, according to the present invention, the rod interval on the lower end side from the section is set to become larger as it goes downward, and the rod interval at the lower end of the chute is set to be larger than the rod interval of the section. It is characterized by being.

  In particular, when the rods are curved in a concave shape, the linear distance connecting the rods decreases in the area where the projection gap in the vertical direction between the rods is constant. . However, according to the present invention, the distance between the centers of the rods is increased as it proceeds downward on the lower end side of the area arranged so that the vertical projection gap is constant, and at the lower end of the chute, the above area Since the distance between the rods is larger than the distance between the rods, it is possible to drop the particles having a larger particle size as it proceeds downward, and to further increase the classification effect.

  By the way, if the projection gap in the vertical direction is set smaller than the diameter of the coarse particles of the raw material particles put into the sintering machine, the coarse particles can be prevented from falling. Since the diameter of the coarse particles is around 8 mm, the projection gap is set to 8 mm or less. Desirably, the projection gap is substantially 4 mm or less of the average particle diameter of the raw material particles in order to drop only fine particles. In addition, when the depression angle at which the raw material enters is large, when projecting in the vertical direction, it is possible to make a part of the adjacent rods overlap in the above area and eliminate the gap between the rods in the projected image.

  Hereinafter, a raw material charging apparatus according to a first embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 3 is a schematic vertical sectional view of the raw material charging apparatus. This raw material charging apparatus includes a raw material supply mechanism for supplying the raw material 207 to the pallet 205 and a chute 214.

  The raw material supply mechanism includes a belt-type feeder 203 that uniformly places the raw material 207 in the width direction and moves the raw material 207 in the direction of the arrow.

  The chute 214 has an upper end located near the discharge end of the belt-type feeder 203, a lower end located above the pallet 205, and is inclined in a direction opposite to the moving direction of the pallet 205.

  4 shows a front view of the chute, and FIG. 5 shows a cross-sectional view taken along line AA of FIG. The chute 214 is formed in a screen shape including a plurality of rods 215 arranged in parallel with a predetermined interval from the upper end to the lower end in the width direction of the pallet 205. The chute 214 is formed in a gentle concave shape from the upper end to the lower end. Among the plurality of rods, the rod 215 in the area where the raw material 207 supplied from the belt-type feeder 203 and entering the chute 214 directly collides with the chute 214 has a constant projection gap in the vertical direction. Here, the vertical projection gap refers to a gap between adjacent rods 215 when the rod 215 is viewed from vertically above. When the chute 214 is curved in a concave shape, if the projection gap in the vertical direction is made constant, the linear distance connecting the adjacent rods 215 (hereinafter referred to as the rod interval) becomes shorter as it goes downward. The shortened rod interval in the area is set smaller than the rod distance on the lower end side of the area. Then, the rod interval at the lower end side of the area is increased as it goes downward, and the rod interval at the lower end of the chute 214 is larger than the rod interval of the area. The projection gap in the vertical direction between the rods and the rod interval will be described in detail later in Examples.

  The connecting member 216 connects the plurality of rods 215 constituting the chute 214 to each other with a predetermined interval. For example, four connecting members 216 are attached at a predetermined interval in the width direction of the rod 215.

  A guide chute 217 shown in FIG. 3 is a plate-like chute positioned between the discharge end of the belt feeder 203 and the upper end of the chute 214. If the raw material 207 enters the chute 214 at an appropriate angle and speed, the guide chute 217 is not necessarily required. However, when the supply speed of the raw material 207 changes according to the change in the production rate, the direction of the raw material particles changes even if the guide chute 217 is used. The raw material 207 discharged from the belt-type feeder 203 and further discharged through the guide chute 217 as necessary collides with the upper portion 214a of the chute 214, and slides down the chute 214, a part of which is formed in a screen shape. Change the direction of travel. The remaining part falls from the rod gap of the chute collision part. Since the rods in the area where the raw material collides are arranged so that the projection gap in the vertical direction is constant, the coarse raw material does not fall out of the raw material particles, but the fine raw material falls.

  Among the raw material particles, some of the coarse particles slide down on the chute 214 composed of a plurality of rods 215 and are discharged from the lower end of the chute 214. The remaining part of the coarse particles falls from a wide gap between the rods constituting the lower part 214b of the chute 214, and is supplied onto the great bar 206 in the pallet 205 that continuously moves. On the other hand, the fine-grained raw material falls from the narrow gap between the rods constituting the upper portion of the chute 214 as described above, and is supplied onto the great bar 206 in the pallet 205 that moves continuously. Thus, even when the depression angle of the entry angle of the raw material 207 is larger than the gradient of the upper part 214a of the chute 214, the coarse raw material as the lower layer in the pallet 205 and the fine raw material as the upper layer that becomes finer in the upper part A raw material layer having a segregated particle size is formed.

  FIG. 6 shows a raw material charging apparatus in the second embodiment of the present invention. In this raw material charging apparatus, the raw material supply mechanism includes a hopper 201 having a raw material 207 charged therein and a cut-out gate 201a in the lower portion of the side wall opposite to the moving direction of the pallet 205, and a roll feeder provided at the lower end opening of the hopper 201. The point which consists of 202 differs from said 1st Embodiment.

  In the above embodiment, the case where the chute is curved in a concave shape has been described. However, the chute is not limited to a concave shape, and may be formed, for example, in a linear shape.

  FIG. 7 shows a raw material charging apparatus in the third embodiment of the present invention. In this raw material charging apparatus, the raw material supply mechanism includes a hopper 201 in which the raw material 207 is charged, a hopper 201 having a cut-out gate 201a on the lower side of the side wall opposite to the moving direction of the pallet 205, and a roll provided at the lower end opening of the hopper 201. Unlike the second embodiment, it has a feeder 202 and a roll feeder 218 provided obliquely below the roll feeder. By rotating the roll feeder 218, it is possible to supplementarily adjust the entry angle and speed of the raw material into the chute, thereby mitigating fluctuations.

Examples of the invention will be described in comparison with comparative examples. In both the example and the comparative example, the shape curve of the chute is
y = − {√ (0.456 + 0.12x)} / 0.06 + 11.26, where x ≧ 0 was used. However, x and y are cm values. FIG. 8 is a graph showing the relationship between the rod gap position and the vertical projection gap between the rods in comparison with the example and the comparative example, and FIG. 9 is a comparison between the example and the comparative example. It is a graph showing the relationship between the rod gap position and the rod interval (distance between the centers of the rods). Numbers 1, 2, 3, 4... 21 from the upper end are given to the rod gap positions. In the embodiment, as shown in FIG. 8, the rod gap from 1 to 5 where the raw material hits is set to 4 mm, and the distance between the centers of the rods linearly increases for the lower rod. . For this reason, as shown in FIG. 9, the center-to-center distance between the rods once decreases and then gradually increases. In the comparative example, as shown in FIG. 9, the center-to-center distance between the rods is gradually increased from the upper end of the rod 215 toward the lower end. In FIG. 8, the vertical projection gap between the rods of this comparative example is compared with the example.

  FIG. 10 is a graph showing the shape curve of the example, and the plotted point indicates the center position of the rod. FIG. 11 is a graph showing the shape curve of the comparative example, and the plotted point indicates the center position of the rod. In the chutes of the example and the comparative example, the depression angle of the approach angle of the raw material is made larger than the slope of the upper end of the chute, and the incoming angle of the raw material particles intersects the slope of the upper end of the chute by 13 degrees. It was.

  FIG. 12 shows the relationship between the height in the layer direction, the average particle size in the layer, and the proportion of C and CaO when the raw materials were supplied into the pallet using the devices of the above-described Examples and Comparative Examples. It is a graph. First, the average particle diameter will be described. The average particle size of the example gradually increases from the upper layer to the lower layer. The difference between the particle size of the upper layer and the particle size of the lower layer is about 4.6 mm-2.7 mm = 1.9 mm. On the other hand, the difference in particle size of the comparative example is 4.25 mm-2.9 mm = 1.35 mm. Therefore, it can be seen that in the Examples, a raw material layer having a large classification effect, that is, a large particle size segregation can be obtained.

  Next, the ratio of C will be described. The proportion of C in the example gradually increases from the lower layer to the upper layer. The difference between the lower layer ratio and the upper layer ratio is 3.6 wt. % -2.9 wt. % = 0.7 wt. %. On the other hand, the difference in the ratio of the comparative example is 3.55 wt. % -3.2 wt. % = 0.35 wt. %. Therefore, in the Example, it turns out that a raw material layer with a large C segregation is obtained.

  Finally, the proportion of CaO will be described. The proportion of CaO in the example increases from the lower layer to the upper layer. The difference between the lower layer ratio and the upper layer ratio is 9.9 wt. % -8 wt. % = 1.9 wt. %. On the other hand, the difference in the ratio of the comparative example is 9.5 wt. % -8 wt. % = 1.5 wt. %. Therefore, in the Example, it turns out that a raw material layer with a large CaO segregation is obtained.

DESCRIPTION OF SYMBOLS 1 Hopper 2 Roll feeder 3 Raw material for sintering 4 Flat plate chute 5 Rope or rod 6 Sintering machine pallet 7 Slit gap 8 Raw material layer 9 Grain segregation charging mechanism 10 Drum feeder 201 Hopper 201a Cutting gate 202 Roll feeder 203 Belt type Feeder 205 Pallet 206 Great bar 207 Raw material 214 Chute 214a Upper end side of chute 214 214b Lower end side of chute 214 215 Rod 216 Connecting member 217 Guide chute 218 Roll feeder

Claims (5)

The raw material charging equipment to the sintering machine consists of:
A raw material supply mechanism for supplying sintering raw materials to the pallet;
A chute that is inclined in a direction opposite to the moving direction of the pallet, the upper end of which is located in the vicinity of the raw material supply mechanism, and the lower end of which is located above the pallet;
The chute is composed of a plurality of rods arranged in parallel at a predetermined interval from the upper end to the lower end in the width direction of the pallet,
In the upper part of the chute, and in areas where material falling down collides, said plurality of a certain projection gap in the vertical direction between the rod and less 8 mm,
The chute, that having a concave surface curved toward the lower end thereof from the upper end.   2. The raw material charging apparatus for a sintering machine according to claim 1, wherein at least a part of a rod interval in an area where the falling raw material collides is smaller than a rod interval on a lower end side of the area where the raw material particles collide. . The rod interval on the lower end side from the area where the raw material particles collide is increased as it proceeds downward,
The raw material charging apparatus to the sintering machine according to claim 2 , wherein a rod interval at a lower end of the chute is made larger than a rod interval in an area where the raw material particles collide.   2. The raw material charging device for a sintering machine according to claim 1, wherein the raw material supply mechanism comprises a belt type feeder.   2. The raw material charging apparatus for a sintering machine according to claim 1, wherein the raw material supply mechanism includes a hopper having a raw material charged therein and having a cut-out gate at a lower portion and a roll feeder provided at a lower end of the hopper.

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