JP2005226113A - Method for charging sintering raw material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for charging a sintering raw material capable of attaining the grain size segregation of a sintering raw material by a relatively easy means. <P>SOLUTION: In the method where a sintering raw material is charged onto a sintering machine pallet through a roller feeder composed of a plurality of driving rollers from a feeder below a feed hopper in a sintering machine, operation is performed in such a manner that the circumferential speed of each driving roller is controlled per the unit of the roller group or the individual rollers so as to make that on the upstream side higher than that on the downstream side. Among the plurality of rollers, the circumferential speed of the rollers from the roller on the uppermost stream side to the position of the roller equivalent to the downstream side by 40 to 60% is made higher. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for charging a sintered material, in which a sintered material in an endless moving great-type sintering machine is supplied and charged onto a pallet via a roller feeder configured by arranging a plurality of rollers in parallel. It is about improvement.

  When producing sintered ore used as a raw material for blast furnaces, raw materials obtained by mixing and granulating iron ore, powdered coke, powdered flux, etc. are placed on a continuously moving pallet of an endless moving great sintering machine. In general, it is manufactured (sintered) by sequentially passing an ignition zone and a sintering zone through a pallet and allowing hot air to pass through the sintering raw material layer.

  When supplying the sintering raw material onto the pallet, the upper layer portion is charged with more coke than the lower layer portion, and the lower layer portion is charged so that the raw material particle size is coarser than that of the upper layer portion. It is known that it is preferable from the standpoints of improving the quality of the ore and sintering yield, further reducing the basic unit of the ignition fuel and improving the productivity.

  FIG. 1 is a schematic explanatory view showing the structure of a conventional raw material charging apparatus, in which 1 is a sintered raw material, 2 is a hopper into which the sintered raw material is charged, and 3 is provided at the lower end opening of the hopper. A drum feeder as a raw material supply mechanism, 4 is a chute located below the drum feeder, 5 is a pallet, and 6 is a great bar arranged below the pallet.

  In such a raw material charging apparatus, the raw material 1 charged into the hopper 2 is continuously discharged onto the chute 4 by the drum feeder 3 and supplied onto the great bar 6 in the pallet 5 via the chute 4. It is comprised so that. The chute 4 is a flat guide member having substantially the same width as the pallet 5 and is generally inclined at a predetermined angle in a direction opposite to the moving direction of the pallet 5 (arrow A). It is.

  However, when the flat chute 4 is used as described above, there are the following problems. The sintered raw material 1 sent by the drum feeder 3 slides on a flat chute 4 and is supplied into the pallet 5, but the impact or raw material layer when the sintered raw material 1 falls into the pallet 5. As the angle of repose increases, an avalanche phenomenon occurs in the sintered material layer, and a fault occurs. As a result, the particle size segregation in the layer height direction of the sintering raw material 1 in the pallet 5 and the distribution of the powder coke accompanying it become non-uniform, and the unevenness of the aeration caused by the “avalanche phenomenon” occurs, resulting in sintering yield. In addition, there is a problem that the productivity is lowered.

  In order to solve such problems, various techniques have been proposed so far. As a basic configuration, a technique using a roller feeder in which a plurality of rollers are arranged in parallel instead of the flat chute 4 has been proposed. Such an apparatus configuration will be described with reference to the drawings.

  FIG. 2 is a schematic explanatory view showing the structure of a raw material charging apparatus using a roller feeder, the basic configuration of which is similar to the configuration of the apparatus shown in FIG. 1, and corresponding parts have the same reference numerals. To avoid duplicate explanations. In this apparatus configuration, a plurality of driving rollers 8 that are arranged in parallel in the same plane and rotate in the same direction and are inclined in a direction opposite to the advancing direction of the pallet of the sintering machine are provided. It is configured to send the sintered raw material 1 to the pallet 5 side while sieving through the gap therebetween. In such an apparatus, the “avalanche phenomenon” as described above is basically avoided, and a laminated state of sintered raw materials having a relatively good particle size distribution (particle size segregation) is achieved.

  Various technologies have been proposed as a technology equipped with such a roller feeder, and various ideas have been made from the viewpoint of achieving a good lamination state of the sintering raw material on the pallet. As such a technique, for example, Patent Document 1 discloses that the roller group is divided into a plurality of segments, the rotation direction and the rotation speed are arbitrarily set for each segment, and the brand, particle size, and components of the raw material charged in the pallet carriage A method for controlling segregation is disclosed. Further, in Patent Document 2, the inclination direction of the roller feeder is the same as the movement direction of the pallet, but by appropriately controlling the rotation speed of each roller, the distance between the rollers, the inclination angle of the roller feeder, etc. It has been proposed to achieve good particle size segregation. Further, Patent Document 3 proposes a technique for realizing good particle size segregation while preventing clogging in the roller feeder by using a roller feeder having slits having an opening interval of 15 mm or less.

  On the other hand, the present inventors have also studied improvement of the charging method of the sintering raw material using a roller feeder, and have proposed a technique such as Patent Document 4 as part of the research. In this technique, the target particle size segregation is achieved by arbitrarily adjusting the inclination angle of the roller feeder and the rotation speed of each roll, or by changing the roller interval between the upstream side and the downstream side of the roller feeder. .

In the technologies that have been proposed so far, some effects have been demonstrated depending on the respective technologies. is there. For these reasons, the establishment of a technique that can easily achieve ideal particle size segregation by the simplest possible operation is desired.
JP, 2000-199687, A Claims etc. Republished 2001-67017 Patent Claim etc. Japanese Patent Publication No. 05-2730 No. Claims JP, 2000-63961, A Claims etc.

  The present invention has been made to solve such problems in the prior art, and the object thereof is a method for charging a sintered raw material that can achieve particle size segregation of the sintered raw material by a relatively easy means. Is to provide.

  The method of the present invention that has solved the above problem is that the sintering raw material is charged from the feeder under the feeding hopper of the sintering machine onto the sintering machine pallet via a roller feeder composed of a plurality of driving rollers. In this method, the peripheral speed of the driving roller is managed in units of rollers or individual rollers, and the operation is performed so that the upstream side is faster than the downstream side.

  In carrying out the method of the present invention, it is preferable to increase the peripheral speed of the roller from the most upstream roller to the roller position corresponding to 40 to 60% downstream of the plurality of rollers. It is recommended that the roller be operated so that the maximum peripheral speed is 1.5 to 2 times the minimum peripheral speed. Furthermore, it is preferable to operate the roller feeder at an inclination angle of 30 to 50 °.

  In the present invention, by making the peripheral speed of the drive roll located on the above-mentioned side of the roller feeder faster than the peripheral speed of the downstream drive roller, particle size segregation of the sintered raw material can be achieved relatively easily, The effect of improving the sintering yield and productivity will be exhibited.

  The present inventors examined the means for realizing good particle size segregation from various angles in the charging apparatus as shown in FIG. As a result, if the peripheral speed of the drive roller is managed for each roller group or individual roller and operated so that the upstream side is faster than the downstream side, the particle size segregation of the sintered raw material charged in the pallet is greatly increased. As a result, it was found that productivity and product yield were improved, and the present invention was completed.

  Although not all of the reasons why the above-described effects were exhibited by the present invention, the peripheral speed of the upstream drive roller in the roller feeder is made relatively faster than that of the downstream drive roller. Thus, it is considered that the force applied to the sintering raw material increases, and the larger the particles, the more difficult it is to drop from between the rollers, that is, the same effect as that of apparently reducing the mesh of the sieve can be obtained.

  The present invention is characterized in that the peripheral speed of the driving roller on the upstream side of the roller feeder is made faster than that on the downstream side. However, if the driving roller that increases the peripheral speed is managed in units of rollers or individual rollers, good. For example, in a roller feeder having eight drive rollers, the peripheral speeds of the upstream to the fourth roller group of 4 to 5 are collected (at the same peripheral speed), and the peripheral speed of the downstream drive roller is more than that. The peripheral speed may be managed in units of roller groups so as to increase, or the peripheral speed may be gradually decreased from the upstream side to the downstream side for each roller unit.

  Whichever configuration is adopted, the upstream roller that increases the peripheral speed may be configured to increase the peripheral speed from the most upstream roller to the roller position corresponding to 40 to 60% downstream. preferable. In particular, when the circumferential speed is managed by the roller group, the effect of the present invention is remarkably achieved by the difference in the circumferential speed from the downstream roller group. In addition, when the peripheral speed is managed in units of rollers, the upstream peripheral speed is naturally higher than that of the downstream side, but the difference between the upstream and downstream peripheral speeds is still clear at the above position. It is recommended to control so that it can be distinguished.

  The peripheral speed of the upstream drive roller is preferably controlled to be 1.5 to 2.0 times the peripheral speed of the downstream drive roller. For example, when the peripheral speed is managed in units of roller groups and divided into two roller groups (upstream and downstream), the upstream peripheral speed (maximum peripheral speed) is set to the downstream peripheral speed (minimum). The peripheral speed) may be 1.5 to 2.0 times. Further, when managing in units of rollers, the maximum circumferential speed (the most upstream roller) may be controlled to be 1.5 to 2.0 times the minimum circumferential speed (the most downstream roller).

  The peripheral speed of the roller depends on the radius and the rotational speed of the roller. Therefore, as a configuration for increasing the upstream peripheral speed, (1) increasing the radius of the upstream roller to make the rotation speed of all the rollers the same, (2) increasing the rotation speed of the upstream roller, In the present invention, any configuration can be adopted.

  In carrying out the present invention, the inclination angle of the roller feeder (hereinafter sometimes referred to as “chute angle”; see FIG. 5 described later) is also preferably adjusted appropriately. In the present invention, in order to exhibit the effect of increasing the peripheral speed of the upstream roller more effectively, it is preferable that the angle is about 30 to 50 °. When this angle is less than 30 °, most of the sintered raw material falls from between the rollers, and even if the peripheral speed of the upstream drive roller is increased, the effect cannot be obtained, and exceeds 50 °. As a result, the action of the sintered raw material sliding on the roller feeder increases, and the effect of increasing the peripheral speed of the upstream drive roller is less likely to be exhibited.

  Other conditions for effectively charging the sintering material include the distance between the drive rollers, the gate opening of the feed hopper, the drum feeder rotation speed, the pallet moving speed (cart speed), the sintering material supply speed, etc. However, it is necessary to adjust these conditions appropriately according to the operation.

  Hereinafter, the working effects of the present invention will be described more specifically by way of examples. However, the following examples are not of a nature that limits the present invention, and any design changes may be made in accordance with the gist of the present invention. It is included in the technical scope of For example, in the following embodiment, the peripheral speed of the driving roller is managed as a roller group, and the control of the peripheral speed is controlled by the number of rotations (therefore, the radius of the driving roller is the same). However, the present invention is not limited to this case. Of course.

Example 1
The present inventors used sintering raw materials (raw materials after actual granulation) having a particle size distribution shown in Table 1 below (blending ratio; iron ore: 84.0% by mass, powdered coke: 4.0% by mass, Powdery flux: 12.0 mass%), and the rotational speed control of the upstream drive cola by the apparatus shown in FIG. 2 (number of drive rolls of the roller feeder: 8) The effect on segregation was investigated. The equipment conditions of the roller feeder at this time are as follows, and other conditions are shown in Table 2.

[Roller feeder equipment conditions]
Roller diameter: 60mmφ
Number of rollers: 8 Tilt angle (shoot angle): 43 °
Roller spacing: 20mm

  The results (relationship between the relative average diameter and the distance from the packed bed surface) are shown in FIGS. 3 shows a case where the raw material supply rate is 175.2 kg / min, and FIG. 4 shows a case where the raw material supply rate is 264.4 kg / min. In the figure, “relative average diameter” means the relative value of the particle size at each position with respect to the overall average particle size, and the segregation occurs as the line connecting these values lies (ie, the slope becomes smaller). It shows that (particle size segregation) is strengthened (that is, approaching the ideal particle size distribution).

  From these results, it can be considered as follows. First, when the raw material supply speed is 175.2 kg / min (FIG. 3), the segregation of particle size tends to be gentle (the inclination of the middle layer tends to be small) when the rotation speed of the upstream roller is 150 rpm. It can be seen that when the rotational speed is increased to 200 rpm and 250 rpm, the particle size segregation in the upper layer portion to the middle layer portion is rather deteriorated (the inclination tends to increase).

  On the other hand, when the raw material supply speed is 264.4 kg / min (FIG. 4), the particle size segregation in the upper layer portion to the middle layer portion is improved (the inclination tends to be smaller) as the roller rotation speed is increased. Yes. That is, in any case (even if the difference in raw material supply speed is taken into consideration), it is understood that the raw material particle size segregation is strengthened by increasing the number of rotations of the upstream roller.

  In order to elucidate the reason why the above phenomenon occurs, the present inventors investigated the dispersion state of the sintered raw material (the state in which the pallet is filled) by controlling the rotational speed of the drive roller. The state of the experimental equipment at this time is schematically shown in FIG. That is, assuming a roller feeder in which eight driving rollers are arranged, the position of the sample box arranged below the roller feeder is investigated by controlling the number of rotations of the driving roller. . At this time, the other conditions were the same as above except that the roller feeder inclination angle (chute angle) was set to 50 °. Note that sample boxes # 1 to # 10 have respective box numbers. Box No. 2 is the most upstream roller position of the roller feeder, and the box No. The position 6 corresponds to the roller position on the most downstream side of the roller feeder.

  The raw material dispersion state when the rotational speed of the four upstream driving rollers is changed to 100 to 250 rpm (the rotational speed of the downstream driving roller is constant at 100 rpm) and the raw material supply speed is 175.2 kg / min. Shown in Moreover, the raw material dispersion | distribution state which compared the case where only the upstream drive roller is increased with the case where the rotation speed of all the rollers is increased is shown in FIGS. For example, FIG. 7 shows that when the rotational speed of the upstream drive roller is 150 rpm and the rotational speed of the downstream drive roller is 100 rpm (150 rpm / 100 rpm: ●), the rotational speed of all rollers is 150 rpm (150 rpm: ◆). The comparison is shown (the same concept applies to FIGS. 8 and 9).

  On the other hand, except that the rotation speed of the four upstream drive rollers is changed to 100 to 250 rpm (the rotation speed of the downstream drive roller is constant at 100 rpm), and the raw material supply speed is changed to 264.4 kg / min. The result of investigating the raw material dispersion state in the same manner as in Fig. 10 is shown. Moreover, the raw material dispersion | distribution state which compared the case where only the upstream drive roller is increased and the case where the rotation speed of all the rollers is increased is shown in FIGS. The results of FIGS. 11 to 13 correspond to FIGS. 7 to 9 except for the raw material supply speed.

  From these results, it can be considered as follows. That is, as the number of rotations of the driving roller increases, the sample box No. The raw material charging amount (the amount of the raw material falling from the gap between the driving rollers) to 1 to 6 is reduced. The raw material charging amount to 7 to 10 (the amount of raw material falling from the roller feeder) tends to increase. In addition, when only the number of rotations of the upstream drive roller is increased as compared with the case where the number of rotations of all the driving rollers is increased, when the number of rotations is 150 to 200 rpm, the raw material supply amount is increased. Regardless, it has been found that the dispersion state is ensured (so that segregation is likely to occur). In any case, it has been found that it is preferable to control the rotational speed of the upstream drive roller by 1.5 to 2.0 times compared with the rotational speed of the downstream drive roller.

Example 2
Next, the influence of the number of upstream rollers that increase the number of rotations was investigated. The setting conditions for the sintering charge at this time are as shown in Table 3 below (the other conditions are the same as in Example 1). In Table 3, the roller No. Nos. 1 to 8 are Nos. When counted from the upstream side. It is. A portion surrounded by a double line (=) indicates a region where the rotational speed is controlled.

  The results (relationship between the relative average diameter and the distance from the packed bed surface) are shown in FIGS. 14 shows the case where the raw material supply rate is 175.2 kg / min, and FIG. 15 shows the case where the raw material supply rate is 264.4 kg / min.

  The inventors investigated the dispersion state of the sintered raw material (the state in which the pallet is filled) in which the number of drive rollers that increase the rotational speed. The state of the experimental equipment at this time is schematically shown in FIG. 16 (basically, the same as in FIG. 5). In other words, assuming a roller feeder with eight driving rollers, the positions of the sample boxes arranged below the roller feeder are distributed and charged by changing the number of driving rollers that control the number of rotations. investigated. At this time, the other conditions were the same as in Example 1 except that the tilt angle (chute angle) was 43 °.

  The results (raw material dispersion state) are shown in FIGS. FIG. 17 shows a case where the raw material supply rate is 175.2 kg / min, and FIG. 18 shows a case where the raw material supply rate is 264.4 kg / min.

  From these results, we could consider as follows. That is, increasing the number of upstream drive rollers that increase the rotational speed affects the raw material particle size segregation in the packed bed height direction, but corresponds to about 40 to 60% downstream from the most upstream roller. It can be seen that it is effective to increase the number of rotations of the roller up to the roller position.

Example 3
Next, the effect of the chute angle was investigated. The setting conditions of the sintering charge at this time are as shown in Table 4 below (other conditions are the same as in Example 1).

  The results (relationship between the relative average diameter and the distance from the packed bed surface) are shown in FIGS. 19 to 21 show the results when the chute angle is changed to 30 °, 40 °, and 50 ° when the raw material supply rate is 175.2 kg / min, respectively. The results when the chute angle is changed to 30 °, 40 °, and 50 ° when the raw material supply speed is 264.4 kg / min are shown. Further, in the figure, when the rotational speed of the upstream drive roller is increased, it is referred to as “uneven”, and when the rotational speed of all the drive rollers is the same, it is referred to as “equal”.

  As is apparent from these results, the effect of increasing the rotational speed of the driving roller varies depending on the chute angle, but the segregation promoting effect is achieved up to the chute angle of about 50 ° at the normal feed rate. Moreover, it turns out that the segregation improvement effect by a chute angle fades as the raw material supply speed increases.

Example 4
Next, the effect of roller spacing was investigated. The setting conditions of the sintering charge at this time are as shown in Table 5 below (other conditions are the same as in Example 1).

  The results (relationship between the relative average diameter and the distance from the packed bed surface) when the raw material supply rate is 175.2 kg / min are shown in FIGS. 25 to 27 show the results when the roller interval is changed to 20 mm, 30 mm, and 40 mm, respectively. In the figure, the meanings of “uneven” and “equal” are the same as those in FIGS.

  As is clear from these results, it is understood that the raw material particle size segregation tends to be promoted as the roller interval is reduced. In addition, even when the raw material supply rate was increased (raw material supply rate: 264.4 kg / min), the effect of the cola interval showed a similar tendency, but the effect of improving the particle size segregation was slightly reduced.

It is a schematic explanatory drawing which shows the structure of the conventional raw material charging device. It is a schematic explanatory drawing which shows the structure of the raw material charging device using a roller feeder. It is the graph which showed the relationship between the relative average diameter at the time of the raw material supply speed | rate at 175.2 kg / min when the rotation speed of an upstream roller was increased, and the distance from the packed bed surface. It is the graph which showed the relationship between the relative average diameter at the time of the raw material supply speed | rate 266.4kg / min when the rotation speed of an upstream roller was increased, and the distance from the packed bed surface. It is explanatory drawing which showed typically the state of the experiment equipment when investigating the change of the dispersion state of the sintering raw material by controlling the rotation speed of a drive roller. It is a graph which shows a raw material dispersion | distribution state when changing the rotation speed of four upstream drive rollers into 100-250 rpm and making a raw material supply speed into 175.2 kg / min. It is the graph which showed the raw material dispersion | distribution state which compared the case where the drive roller of an upstream side was increased to 150 rpm, and the case where the rotation speed of all the rollers was increased to 150 rpm. It is the graph which showed the raw material dispersion | distribution state which compared the case where the drive roller of an upstream side was increased to 200 rpm, and the case where the rotation speed of all the rollers was increased to 200 rpm. It is the graph which showed the raw material dispersion | distribution state which compared the case where the upstream drive roller was increased to 250 rpm, and the case where the rotation speed of all the rollers was increased to 250 rpm. It is a graph which shows a raw material dispersion | distribution state when changing the rotation speed of four upstream drive rollers into 100-250 rpm and making a raw material supply speed | rate into 264.4 kg / min. It is the graph which showed the raw material dispersion | distribution state which compared the case where the drive roller of an upstream side was increased to 150 rpm, and the case where the rotation speed of all the rollers was increased to 150 rpm. It is the graph which showed the raw material dispersion | distribution state which compared the case where the drive roller of an upstream side was increased to 200 rpm, and the case where the rotation speed of all the rollers was increased to 200 rpm. It is the graph which showed the raw material dispersion | distribution state which compared the case where the upstream drive roller was increased to 250 rpm, and the case where the rotation speed of all the rollers was increased to 250 rpm. 6 is a graph showing the relationship between the relative average diameter and the distance from the packed bed surface when the raw material supply speed is 175.2 kg / min when the number of rollers for increasing the number of rotations is changed. It is the graph which showed the relationship between the relative average diameter and the distance from the packed bed surface when the raw material supply speed | rate is 264.4 kg / min when changing the number of the rollers which increase rotation speed. It is explanatory drawing which showed typically the state of the experiment equipment when investigating the change of the dispersion | distribution state of the sintering raw material by the number of drive rollers which increases rotation speed. It is a graph which shows a raw material dispersion | distribution state when a raw material supply speed | rate is 175.2 kg / min when changing the number of the drive rollers which increase rotation speed. It is a graph which shows a raw material dispersion | distribution state when a raw material supply speed is 264.4 kg / min when changing the number of the drive rollers which increase rotation speed. It is the graph which showed the relationship between the relative average diameter when the chute angle was 30 degrees, and the distance from the packed bed surface when the raw material supply speed was 175.2 kg / min. 6 is a graph showing the relationship between the relative average diameter and the distance from the packed bed surface when the chute angle is 40 ° when the raw material supply rate is 175.2 kg / min. 6 is a graph showing the relationship between the relative average diameter and the distance from the packed bed surface when the chute angle is 50 ° when the raw material supply rate is 175.2 kg / min. 6 is a graph showing the relationship between the relative average diameter and the distance from the packed bed surface when the chute angle is 30 ° when the raw material supply rate is 264.4 kg / min. 6 is a graph showing the relationship between the relative average diameter and the distance from the packed bed surface when the chute angle is 40 ° when the raw material supply rate is 264.4 kg / min. 6 is a graph showing the relationship between the relative average diameter and the distance from the packed bed surface when the chute angle is 50 ° when the raw material supply rate is 264.4 kg / min. It is the graph which showed the relationship between the relative average diameter and distance from the packed bed surface when a roller space | interval shall be 20 mm when a raw material supply speed | rate is 175.2 kg / min. It is the graph which showed the relationship between the relative average diameter and distance from the packed bed surface when a roller space | interval shall be 30 mm when a raw material supply speed | rate is 175.2 kg / min. It is the graph which showed the relationship between the relative average diameter when the raw material supply speed | rate is 175.2 kg / min and it is set as roller space | interval 40 mm, and the distance from the packed bed surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sintering raw material 2 Hopper 3 Drum feeder 4 Chute 5 Pallet 6 Great bar 8 Drive roller

Claims (4)

  In a method of charging a sintering raw material from a feeder under a feeder hopper of a sintering machine onto a sintering machine pallet via a roller feeder composed of a plurality of driving rollers, the peripheral speed of the driving roller is set to a group of rollers. Alternatively, a method for charging a sintered material, wherein the operation is performed in units of individual rollers so that the upstream side is operated faster than the downstream side.   The method for charging a sintered raw material according to claim 1, wherein the peripheral speed of the roller from the most upstream roller to the roller position corresponding to 40 to 60% downstream of the plurality of rollers is increased.   The method for charging a sintered material according to claim 1 or 2, wherein the roller is operated so that the maximum peripheral speed is 1.5 to 2.0 times the minimum peripheral speed.   The method for charging a sintered raw material according to any one of claims 1 to 3, wherein the roller feeder is operated at an inclination angle of 30 to 50 °.

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