JP5316403B2 - Powder kneading method and apparatus, and powder agglomeration method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a powder kneading method which can secure properties, such as a particle size and bulk density, of a kneaded material in proper ranges even when the supply amount of powder is increased or decreased in a horizontal kneading apparatus, such as a horizontal kneader and a paddle mixer, for kneading dried powder and a binder. <P>SOLUTION: In the powder kneading method using the horizontal kneading apparatus for kneading the dried powder and the binder, a position for adding the binder to the kneading apparatus can be changed in the longitudinal direction, when the supply amount of the powder is increased or decreased, the retention amount of the powder in the kneading apparatus is controlled to be constant and the addition amount of the binder is adjusted so that a ratio of the binder added to the powder is constant before and after the increase or decrease in the supply amount of the powder, and when the supply amount of the powder is increased or decreased, the position for adding the binder is moved to the upstream side or the downstream side of the kneading apparatus in proportion to an increase or decrease ratio of the supply amount of the powder. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a kneading method using a horizontally long kneader such as a horizontal kneader or a paddle mixer for kneading dried powder and a binder, a kneading apparatus, and a method for agglomerating powder after kneading. is there. In particular, the pulverized coal generated when the coke pretreatment coal is dried with a fluidized bed drying classifier is put into a roll agglomerator and agglomerated into a plate shape such as a horizontal groove shape or a corrugated plate shape. Further, the present invention relates to a method and apparatus for kneading pulverized coal and a binder using a horizontally long kneading apparatus such as a horizontal kneader or a paddle mixer, and a method for agglomerating powder after kneading.

When heat-treating a powder containing moisture at a high temperature such as 1000 ° C., it is effective to dry the powder in advance in order to reduce the amount of heat during the heat treatment. However, when the powder containing moisture progresses, there is a tendency that a problem that dust is generated during conveyance occurs. As such a drying process, there is a pretreatment method for a coal raw material charged in a chamber furnace type coke oven. When the coal for coke pretreatment is dried, not only can the heat of carbonization during coking be reduced, but also the charging density of the coal into the coke oven can be increased to increase coke quality and production.
Even if the blending ratio of non-slightly caking coal with low caking properties is increased, if the coke quality can be improved to a level necessary for blast furnace operation, the raw material cost of coke can be reduced, and inexpensive coke can be produced. It is very important to increase the blending ratio of non-slightly caking coal, because there is a tendency for the lack of caking coal of good quality worldwide. Aiming at these effects, humidity control coal equipment that can increase coke quality and production volume by increasing the bulk density at the time of charging in the coke oven by drying the coal as the raw material for coke by pretreatment. Admission is implemented in many coke ovens.
However, when the dryness of coal is increased, there arises a problem that dust generation and carryover become severe when coal is transported to a coke oven or charged. This is because the pseudo-particles collapse due to drying, and the fine powder that easily generates dust increases. For this reason, the moisture conditioning coal charging method can only dry coal moisture to about 5 mass% (moisture mass / coal mass-wet × 100).
Therefore, the dusting fine powder that becomes a problem during coal drying is separated in advance, and a binder is added to the dusting fine powder in a horizontally long kneading apparatus to knead it into pseudo particles, or further kneaded (Hereinafter referred to as the kneaded product) is formed into briquettes, pockets, etc. with a roll molding machine, or agglomerated into a plate shape such as a transverse groove or corrugated sheet with a roll agglomerate, and coarse particles remaining after classification Coal pretreatment methods that can suppress dust generation and carryover by mixing with coal and charging into a coke oven have been proposed. Here, as a means for separating the dusting fine powder, there is a vibrating sieve or the like, but a fluid bed drying classifier is general. The classifier is a type that supplies coal for coke continuously to a fluidized bed and classifies and separates dusting fine powder while supplying hot air of about 100 to 300 ° C from below to dry the coal. Yes, the particle size of the fine powder to be classified can be adjusted by the gas flow rate of the classification part at the upper part of the fluidized bed.

  Among these, the method of agglomerating into a horizontal groove or corrugated plate with a roll agglomerator, in addition to reducing dust generation, further suppresses segregation of the agglomerates, and in the coke oven. The present inventors have found and proposed that the charging density can be controlled within an appropriate range (Patent Document 4).

When the coal for coke is classified by a fluidized bed drying classifier or the like, the amount of fine powder to be separated varies depending on coal moisture, coal particle size, and the like. For this reason, in the above-mentioned coal pretreatment method, when the processing amount of fine powder increases or decreases, the kneading state of the fine powder and the binder changes even if the binder addition ratio is constant, and various problems occur.
For example, when the processing amount of fine powder is increased, the dispersion of the binder into the fine powder of the kneaded product becomes insufficient, and the kneaded product that is partially excessive in the binder adheres to the transport line and becomes an obstacle to operation, and the binder is insufficient. The resulting kneaded product was insufficiently pseudo-particles and generated dust. Even if the kneaded material is agglomerated, the kneaded material with an excessive binder has a problem that the kneaded material adheres to the hopper or roll during the agglomeration and becomes an obstacle to the operation. There was a problem that yield decreased, agglomerates collapsed during transport to the coke oven, and dust generation and carry-over became severe.

  Moreover, when the processing amount of fine powder decreased (the amount of binder did not change), dispersion | distribution of the binder to the fine powder of a kneaded material became excess, and the pseudo particle collapse | crumbled and generated dust. Even if the kneaded material is agglomerated, the bulk density of the kneaded material is reduced, so that the agglomerated material does not become dense and the strength and yield decrease, and the agglomerated material collapses during the conveyance process to the coke oven. There was a problem that dust generation and carry-over increased. Therefore, even if the processing amount of fine powder increases or decreases, it is necessary to take measures for stabilizing the properties of the kneaded product such as pseudo-particle formation (hereinafter referred to as particle size) and bulk density.

For example, in Patent Document 1, the bulk density of the kneaded product discharged from the kneading apparatus is measured, and the retention amount (space factor) of the kneading apparatus is adjusted by fuzzy inference to adjust the properties of the kneaded product. A method for stabilization is disclosed.
Further, as a method for producing quasi-granulated material for charging a coke oven by kneading pulverized coal, Patent Document 2 discloses a powder temperature (70) using a horizontal kneading apparatus with a built-in paddle. 150 ° C.) and a processing amount (20, 40 t / Hr), a method for stabilizing a pseudo-granulated product in which a binder addition position of a kneading apparatus is intermittently adjusted in three stages (regions I, II, III). It is disclosed. Specifically, when the input amount of pulverized coal is constant at 20 t / h, when the temperature increases from 70 to 150 ° C., the binder input position is moved from region I to downstream region III, and the temperature is constant at 150 ° C. In this case, when the input amount of pulverized coal is increased from 20 to 40 t / h, the input position of the binder is moved from the region III to the upstream region II.
As for the agglomeration method when the supply amount of powder increases or decreases, a method of adjusting the roll pressing force according to the supply amount can be considered, but the operation of the agglomerator is difficult and the equipment cost increases. End up. Therefore, even if the supply amount increases or decreases, the roll pressing force is kept constant, the roll rotation speed is adjusted in proportion to the increase / decrease rate of the supply amount, and the rotation speed of the screw feeder is controlled so that the gap between rolls is constant. The present inventors have found and proposed that the technique is effective (see Patent Document 3).

JP-A-6-47266 JP 2007-297537 A JP 2008-132537 A JP 2007-284557 A

  However, when the method described in Patent Document 1 is applied to a method of kneading powder using a binder, there is a problem that it cannot be applied to a case where the amount of processing greatly increases or decreases. That is, a normal kneading apparatus for kneading powder and a binder with a stirring blade has an appropriate retention amount (a space factor). If the space factor is too low, the bottom of the kneading device is greatly affected and the stirring blade is kneaded. In addition, the binder adheres to the shaft and the stirring blades and hinders the operation of the kneading apparatus, and conversely, if the space factor is too high, the powder exceeding the blade height will be generated when stirring. This is because it has a problem of being discharged without being able to fully exhibit the kneading action of the stirring blade. Therefore, in the method of kneading powder using a binder, there is a limit to keeping the properties of the kneaded material constant by changing the space factor.

  Moreover, in the method of patent document 2, when the amount of powder processing changes intermittently, the input position of a binder is changed intermittently, and the amount of processing of the powder to increase / decrease is intermittent. It is not assumed that the setting value is not met. However, the amount of fine powder generated in the actual operation of classifying raw coal for coke with a fluidized bed drying classifier is greatly increased because the amount of raw coal input to the fluidized bed drying classifier and the water content may greatly increase or decrease. In some cases, the amount of fine powder kneading is not limited to two or three stages, and in some cases may vary from 1 / several times to several times the amount of steady operation. For this reason, the method described in Patent Document 2 has a problem that properties such as the particle size and bulk density of the kneaded product become unstable when the processing amount of the increasing / decreasing powder deviates from the set value. The reason is that when the amount of powder processed deviates from the set value, the binder addition ratio deviates from the predetermined value. Since the binder addition ratio greatly affects kneading and agglomeration, it is important to adjust the binder addition ratio to be constant even when the amount of processing of the powder is increased or decreased, but in the method described in Patent Document 2, When the increase / decrease in the processing amount deviated from the set values assumed in two or three stages, the properties of the kneaded material were unstable.

Further, as described above, keeping the space factor in the kneader constant is important for stabilizing the properties of the kneaded material. However, Patent Document 2 describes that when the amount of pulverized coal increases, In order to keep the volume ratio (pulverized coal level) constant, it is disclosed to increase the moving speed of the pulverized coal in the kneader.
Patent Document 2 does not specifically describe means for adjusting the moving speed of pulverized coal, but in order to change the moving speed in a kneading apparatus incorporating a paddle, it is common to change the rotational speed of the paddle. It is considered to be appropriate.
However, as a result of studies by the inventors, it has been found that if the rotational speed of the paddle is changed, the balance between the centrifugal force and gravity of the paddle is lost, and an appropriate kneading state cannot be maintained. This is probably because if the rotational speed of the paddle is too high, the centrifugal force becomes excessive and the kneading action of the paddle cannot be exhibited, and if the rotational speed is too low, the kneading action of the paddle to lift the powder cannot be exhibited.

  Furthermore, since the technique disclosed in Patent Document 2 may have a temperature of the powder of 100 ° C. or higher, an inexpensive tar cake containing light or volatile components that evaporate at about 100 ° C. or before purification. It is not assumed that crude tar is used as a binder. This is because even if powders of 100 ° C or higher are kneaded or agglomerated, moisture and light volatiles evaporate, and not only the pseudo particles collapse, but also moisture and volatiles adhere to the transportation equipment and dust collection equipment. This is because it becomes an operational obstacle.

  The present invention solves the above-mentioned problems of the prior art, and pulverized coal generated when the coke pretreatment coal is dried and classified by a fluidized bed drying classifier is put into a roll agglomerator to form a horizontal groove. In the kneading of pulverized coal and binder using a horizontally long kneading device equipped with a stirring blade inside, before the agglomeration into a plate shape such as a plate or a corrugated plate, the kneaded product even if the throughput is increased or decreased Powder and binder kneading method and kneading apparatus that can stabilize properties such as particle size and bulk density, and suppress dust generation and carryover during transportation and charging, and agglomeration of kneaded powder It aims to provide a way to do.

As a result of intensive studies, the present inventors have used a horizontal kneading apparatus equipped with stirring blades inside the pulverized coal generated when the coke pretreatment coal is dried and classified by a fluid bed drying classifier. When kneading with the binder, even if the processing amount (flow rate of pulverized coal to the kneading apparatus) increases or decreases, (A) the addition ratio of the binder is kept constant; (A) to (D), (C) keeping the rotation rate of the stirring blade constant, (D) adjusting the binder addition position according to increase or decrease in the processing amount. By satisfying all, it has been found that properties such as particle size and bulk density of the kneaded product can be stabilized, and dust generation and carry-over at the time of transportation and charging can be suppressed, and the invention has been made.
Moreover, even if it used tar soot or the crude tar before refinement | purification as a binder by satisfy | filling said (A)-(C), it turned out that it can be used without a problem.

The gist of the present invention is as follows.
(1) The pulverized coal obtained by classifying the coke pretreatment coal into fine powder and coarse particles with a fluidized bed drying classifier is supplied to a horizontally long kneading apparatus with a built-in stirring blade, and a binder is added to the kneading apparatus. A powder kneading method for kneading both,
The binder contains a crude tar before refining tar containing moisture and solids,
While keeping the rotation speed of the stirring blade built in the kneading device constant, and controlling the amount of residence of the kneaded material in the kneading device to be constant,
And the addition position of the binder is variable in the longitudinal direction of the kneading apparatus, and when the supply amount of the powder is increased or decreased, the addition ratio of the binder to the pulverized coal is before and after the increase or decrease in the supply amount of the powder. The amount of the binder added is adjusted to be constant at the same time, and the binder addition position is adjusted to the upstream side of the kneading device if the powder supply amount is increased. A powder kneading method, wherein the powder is changed in proportion to an increase / decrease rate of the supply amount of the powder on the downstream side of the kneading apparatus.
(2) The means for changing the addition position of the binder in the longitudinal direction of the kneading apparatus is provided by providing a mechanism for moving the binder addition nozzle in the longitudinal direction of the kneading apparatus ( 1) Symbol placement powder kneading method.
( 3 ) The binder addition nozzle for adding the binder, wherein the means for changing the addition position of the binder in the longitudinal direction of the kneading apparatus is provided with the binder addition nozzle at four or more positions in the longitudinal direction of the kneading apparatus. (1) Symbol placement powder kneading method which is characterized in that due to switch.
( 4 ) Powders characterized in that the powder kneaded by the powder kneading method according to any one of (1) to ( 3 ) is charged into a roll agglomerator and agglomerated into a plate shape. Body agglomeration method.

( 5 ) A powder kneading apparatus for use in the powder kneading method according to any one of (1) to ( 3 ), wherein the cylinder is open or sealed upward and extends in the horizontal direction, and the cylinder A powder supply unit installed on the upstream side of the body, a powder discharge unit installed on the downstream side of the cylinder, and between the powder supply unit and the powder discharge unit and horizontally in the cylinder A kneading part provided with a stirring blade attached to a rotating shaft extending to the shaft, a driving device for rotating the rotating shaft attached with the stirring blade, and the kneading part containing a crude tar before refining tar containing water and solids A binder supply nozzle for supplying a binder; a powder supply device for supplying powder to the powder supply unit; and a binder supply device for supplying a binder to the binder addition nozzle; The amount of powder retained in the kneading device And a feedforward control device that adjusts the amount of binder added so that the ratio of the binder to the powder is constant before and after the supply amount of the powder is increased or decreased. And a plurality of the binder addition nozzles are provided in the longitudinal direction of the kneading apparatus and have a mechanism for switching nozzles for charging the binder, or have a mechanism capable of moving in the longitudinal direction of the kneading apparatus. When the supply amount of the powder increases or decreases when the supply amount of the powder increases or decreases, the supply amount of the powder increases toward the upstream side of the kneading device, and when the supply amount of the powder decreases, decreases toward the downstream side of the kneading device. The powder kneading apparatus characterized in that the addition position in the longitudinal direction of the binder addition nozzle can be changed in proportion to the increase / decrease rate of the supply amount of the powder.
In addition, the horizontally long kneading apparatus used in the present invention includes a stirring blade on a shaft (rotating shaft) installed in a direction perpendicular to gravity, and kneads the powder and binder by rotating the shaft. It is a horizontally long kneading device such as a horizontal kneader or a paddle mixer, and the longitudinal direction refers to the direction in which the shaft extends. Further, the upstream side refers to the side for supplying the powder, and the downstream side refers to the side for discharging the kneaded material.

According to the present invention, pulverized coal generated when coal for coke pretreatment is dried and classified by a fluid bed drying classifier is put into a roll agglomerator and agglomerated into a plate shape such as a transverse groove shape or a corrugated plate shape. In the kneading of pulverized coal and binder using a horizontally long kneader equipped with stirring blades inside, the particle size and bulk of the kneaded product are increased or decreased even if the amount of powder (pulverized coal) is increased or decreased. It becomes possible to stabilize properties such as density, and it is possible to suppress dust generation and carry-over at the time of conveyance to the subsequent process or charging. This will improve the coke quality and increase the production volume by increasing the coal charging density in the coke oven while suppressing dust generation and carryover during transportation to and charging to the chamber type coke oven. Can be expected.
In addition, by agglomerating the kneaded material into a plate shape with a roll aggregator, the generation of dusting fine powder can be further reduced, so that not only dust generation and carryover can be further reduced, but also coal Since the density can be further increased, the coke quality and the production amount can be further improved.

It is the figure which showed one example of the flow of the manufacturing method of the agglomerate using the powder kneading method which concerns on this invention. It is the figure which showed the image of the kneading | mixing state of powder and a binder, (a) is the kneading | mixing initial stage, (b) is kneading | mixing insufficient, (c) shows the optimal kneading | mixing, (d) shows the state of excessive kneading, respectively. It is the schematic diagram which showed the powder kneading apparatus of this invention, (a) is sectional drawing perpendicular | vertical to the longitudinal direction of a kneading apparatus, (b) is side sectional drawing, (c) shows plane sectional drawing, respectively. It is the figure which showed the relationship between the bulk density of the kneaded material with respect to the powder supply amount which concerns on 1st embodiment of this invention, and the particle ratio of 0.3 mm or less of a kneaded material. It is the figure which showed the relationship between the drop strength of the agglomerate with respect to the powder supply amount which concerns on 1st embodiment of this invention, and a yield. It is the figure which showed the relationship between the bulk density of the kneaded material with respect to the powder supply amount which concerns on 2nd embodiment of this invention, and the particle ratio of 0.3 mm or less of a kneaded material. It is the figure which showed the relationship between the fall intensity | strength of the agglomerate with respect to the powder supply amount which concerns on 2nd embodiment of this invention, and a yield. It is the figure which showed the relationship between the bulk density of the kneaded material with respect to the powder supply amount ratio which concerns on 3rd embodiment of this invention, and the particle ratio of 0.3 mm or less of a kneaded material. It is the figure which showed the drop intensity | strength and yield of the agglomerate with respect to the powder supply amount ratio which concerns on 3rd embodiment of this invention. It is the figure which showed the relationship between the bulk density of the kneaded material with respect to the powder supply amount ratio which concerns on the comparative example 1, and the particle ratio of 0.3 mm or less of a kneaded material. It is the figure which showed the relationship between the drop strength of the agglomerate with respect to the powder supply amount ratio which concerns on the comparative example 1, and a yield. It is the figure which showed the relationship between the bulk density of the kneaded material with respect to the powder supply amount ratio which concerns on the comparative example 3, and the particle ratio of 0.3 mm or less of a kneaded material. It is the figure which showed the relationship between the drop strength of an agglomerate with respect to the powder supply amount ratio which concerns on the comparative example 3, and a yield.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a kneading and agglomeration flow of pulverized coal (hereinafter also referred to as “powder”) after a fluidized bed drying classifier process according to the first embodiment of the present invention. After the powder is classified into fine powder and coarse particles using a fluidized bed drying classifier or vibrating sieve, the classified fine powder is supplied to the powder hopper 1 and the level detector 2 stores the powder in the powder hopper. While controlling the amount of powder, a predetermined amount of powder is supplied to the kneading device via the powder supply unit 15 of the kneading device 6 by the powder supply device 3.

  The type of the level detector 2 includes a microwave level meter, a capacitance type level meter, and the like, and may be appropriately selected in consideration of powder properties, equipment costs, and the like. If the fluctuation of the bulk density of the powder is large, it is desirable to measure the mass of the powder hopper 1 with a load cell or the like instead of a level detector and manage the amount of powder in the hopper.

  The powder supply device 3 is generally inexpensive and has a rotary valve, but other supply devices such as a screw conveyor and a table feeder may be used.

  Binder for improving the quality such as yield and strength of the agglomerate while making the powder pseudo particles is supplied to the binder hopper 4 while controlling the amount of binder in the binder hopper with the level detector 2 '. Then, a predetermined amount of the binder is supplied to the kneading device 6 through the binder addition nozzle 7 by the binder supply device 5. As the binder, tar is preferably used from the viewpoints of improving coke quality, increasing the amount of coke produced, and treating by-products, but is not limited thereto and may be selected as appropriate. Moreover, when using tar, it is preferable from a viewpoint of a by-product process and cost reduction to use the rough | crude tar before water | moisture content and solid content and tar tar refinement | purification.

  The type of the level detector 2 ′ includes a microwave level meter, a flow type level meter, and the like, and may be appropriately selected in consideration of the binder property, facility cost, and the like. If the fluctuation of the bulk density of the binder is large, it is preferable to measure the mass of the binder hopper 4 with a load cell or the like instead of a level detector to manage the amount of binder in the hopper.

  The binder supply device 5 may be the same as the powder supply device 3 described above when the binder is powder. When the binder is a liquid, the pump is inexpensive and general, but other supply methods using a flow control valve or the like may be used. The binder is supplied to the kneading apparatus 6 using a binder addition nozzle 7. The binder addition nozzle 7 may be a single tube, but when the binder is a liquid, it is desirable to spray in order to more uniformly disperse the liquid binder in the powder. The spraying method may be performed by pressurizing the liquid binder and directly spraying with a nozzle, or by spraying with a gas with a two-fluid nozzle, and may be appropriately selected depending on the sprayability of the liquid binder.

  Further, the binder supply nozzle has a structure capable of adjusting the binder addition position in the longitudinal direction of the kneading apparatus 6. Specifically, if the cylindrical body 6a of the kneading apparatus 6 is an open system without a ceiling, the binder pipe is a movable pipe such as a flexible hose, and the binder addition nozzle 7 is provided with a rail in the longitudinal direction of the kneading apparatus. A structure that can be moved by, for example, may be used. The means for moving the carriage for adjusting the position of the binder addition nozzle may be either manually adjusted or automatically adjusted by a hydraulic cylinder or the like. If the cylindrical body 6a of the kneading device 6 is a closed system with a ceiling, the binder addition nozzle 7 is installed at four or more different positions in the longitudinal direction of the kneading device, and the nozzle to be used is selected according to the conditions, What is necessary is just to switch and adjust the nozzle to be used by opening and closing the valve. In view of the longitudinal size of a general horizontally long kneader, it is more preferable to use 5 or more stages for uniform dispersion of the binder.

  The binder-powder kneading apparatus 6 used in the present invention may be a batch type or a continuous type, but a continuous type is desirable when processing powder continuously. There are various types of continuous kneaders, such as paddle mixers and pin mixers, but a horizontally long kneader equipped with a stirring blade 9 on a shaft 17 installed in a direction perpendicular to gravity, generally called a horizontal kneader. Is desirable from the viewpoint of return on investment. There are various types of stirring blades 9 such as a rod shape, a blade shape, a screw shape, and the like.

  The kneading apparatus is classified in the longitudinal direction into a supply conveyance unit 11, a kneading unit 10, and a discharge unit 12. The supply conveyance unit 11 includes an opening 15 for supplying the powder discharged from the powder supply device 3 to the kneading device, and a screw 16 for conveying the powder to the kneading unit 10. The discharge unit 12 includes an opening 15 and a screw 16 for discharging the kneaded powder from the kneading apparatus. The kneading part 10 includes a stirring blade 9 for kneading the powder and the binder, and is a part from the position of the binder addition nozzle 7 to the discharge part 12. The binder is added to the powder, and the kneading of the powder and the binder is started by rotating the rotating shaft 17 by the driving device M and rotating the stirring blade 9. Therefore, the range of the supply conveyance unit 11 and the kneading unit 10 changes as the position of the binder addition nozzle 7 changes.

Further, as shown in FIG. 1 or FIG. 3B, a weir 13 is provided on the upstream side of the discharge unit 12 so as to be movable up and down, and the amount of powder retained in the kneading apparatus (the space factor) is adjusted as will be described later. can do. The adjustment method for keeping the retention amount (space factor) constant is not only a method for adjusting the height of the weir 13 but also a method for adjusting the inclination in the longitudinal direction of the kneader 6, and a discharge unit. There is a method of adjusting the position or opening degree of 12, etc., which may be selected as appropriate.
The method of adjusting the height of the weir 13 is a method of adjusting the height of the weir up and down to adjust the retention amount of the powder in the kneader, but the relationship between the powder processing amount, the height of the weir and the retention amount in advance. The height of the weir may be adjusted according to the increase or decrease in the amount of processed powder, or the height of the weir may be automatically adjusted while measuring the amount of residence with a weight or level meter. . Further, the method of changing the height of the weir may be an electric motor or human power.

  The method of adjusting the inclination of the kneading machine 6 in the longitudinal direction is that the kneading machine 6 itself is inclined by moving the vicinity of the discharge part 12 or the opening 15 for supplying the powder in the kneading machine 6 with a hydraulic device or the like. In this method, the amount of powder retained in the kneader is adjusted by accelerating or suppressing the discharge of the powder. The inclination may be adjusted according to the increase or decrease, or the inclination may be automatically adjusted while measuring the staying amount with a weight or a level meter.

In the method of adjusting the position or opening of the discharge unit 12 described above, a door body (not shown) that moves in the longitudinal direction or the circumferential direction of the kneading device is provided at the opening of the discharge unit so as to cover the opening. It is a method of adjusting the position or opening of the discharge unit 12 by moving the body to adjust the amount of powder retained in the kneader. Investigate the relationship and adjust the position or opening according to the increase or decrease in the amount of powder processing, or adjust the position or opening while measuring the amount of residence with a weight or level meter. good. Moreover, the change method of the position or opening degree of the said discharge part is possible by moving a door body with an electric motor or human power.
Note that, when the space factor is kept constant, some fluctuations occur in the equipment, but it is acceptable if it is within a range of ± 5%.

  In addition, even if the amount of processed powder is increased or decreased, there is no need to adjust the space factor such as the weir 13 as long as the amount of powder retained (the space factor) in the kneading apparatus is within an appropriate range. Absent. For example, as shown in FIG. 1, a horizontal kneader in which the shape of the stirring blade 9 is a fan shape and the installation direction to the shaft 17 is alternately arranged on the feed side and the return side, the processing amount of the powder is increased or decreased. However, since the retention amount of the powder in the kneading apparatus hardly changes, a space factor adjusting means is not required, which is preferable from the viewpoint of equipment cost and kneading stability.

  Also, the method of providing the weir 13 is preferable from the viewpoint of equipment cost and kneading stability because the structure is simple and easy to set. And after kneading | mixing powder and a binder with the said kneading apparatus 6, the kneaded material is agglomerated with the roll agglomerator 14. FIG. In the present invention, the retention amount (space factor) is the volume of the powder in the kneading part relative to the volume of the kneading machine (cylinder) corresponding to the height from the bottom of the kneading part of the kneading device to the height of the stirring blade. To do. That is, it substantially corresponds to the ratio of the cross-sectional area in which the stirring blade of the kneading part is filled with the powder.

  The powder supplied to the kneading device 6 from the powder supply device 3 because the amount of powder supplied to the powder hopper 1 also changes when the moisture, particle size, etc. of the powder to be classified (for example, coal) changes. The amount of supply increases or decreases. In addition, the supply amount of the powder supplied to the kneading apparatus 6 is increased or decreased even when the production amount is changed due to the production plan, operation troubles, or the like. When the supply amount of the powder increases or decreases in this way, the kneading state of the powder and the binder changes, and properties such as the particle size distribution and bulk density of the kneaded product change. When the particle size distribution or bulk density of the kneaded product varies, the quality of the agglomerated product such as yield and strength when the kneaded product is agglomerated also varies.

  The reason will be described with reference to FIGS. (A) is an image diagram of the initial stage of kneading when the powder and binder are supplied to the kneading apparatus and the kneading is started. Insufficient dispersion of the binder produces “dama” and deteriorates the quality of the agglomerate. Here, “dama” is a lump with powder adhering to the surface of the droplets of the binder, and “dama” is generated when a powder part with insufficient binder or a powder part with excessive binder is generated. The quality of the kneaded material and the agglomerated material fluctuates and operation troubles such as adhesion are caused. If the kneading is continued, the lumps are crushed by the shearing action caused by the rotation of the stirring blades and become the state of (b), but the dispersion of the binder is still insufficient, so that the kneaded product is not sufficiently quasi-particled, The quality of the product is not improved. When the kneading is further continued, the binder is moderately dispersed and the powders are further brought into contact with each other to become pseudo particles (c), the dusting fine powder in the kneaded material is reduced, and the bulk density of the kneaded material is reduced. To increase. Moreover, when the kneaded material is agglomerated, the quality of the agglomerated material such as yield and strength is improved for the same reason. If the kneading is further continued, the pseudo particles are in a state of being crushed (d), the bulk density of the kneaded material is lowered, and the binder is too thinly extended on the powder surface to agglomerate the binder. The effect cannot be exhibited and the quality of the agglomerate is lowered. Therefore, even if the supply amount of the powder is increased or decreased, the present invention etc. has intensively studied in order to stabilize the yield and strength of the agglomerate, and thus the particle size and bulk density of the kneaded product, and the following method is used. I found it.

  Since the addition ratio of the binder to the supplied powder has the most influence on the quality such as the particle size and bulk density of the kneaded product, the yield and strength of the agglomerate, the powder should be set after setting the appropriate binder ratio. It is necessary to control so that the addition ratio of the binder becomes constant even if the supply amount of is increased or decreased. An example of the control method is shown in FIG. In this method, a powder supply amount signal from the powder supply device 3 is received by the feedforward control device 8 to calculate a binder addition amount, and a signal is sent to the binder supply device 5 to increase or decrease the powder supply amount. However, the binder addition amount is adjusted so that the binder addition ratio is constant. In addition, since the addition amount of a binder changes with properties of the powder to be kneaded, the kind of the binder, the use (molding method) of the kneaded material, etc., it goes without saying that it is determined in advance through experiments or the like.

When the supply amount of the powder increases or decreases, the kneading state of the powder and the binder in the kneading apparatus 6 changes, and not only the properties such as the particle size and bulk density of the kneaded material, but also the quality such as the yield and strength of the agglomerated material. Also fluctuate.
In order to bring the mixing state of the powder and the binder into an appropriate range even if the supply amount of the powder is increased or decreased, the first method is to adjust by changing the staying amount (space factor) in the kneading apparatus 6 which is a conventional technique. 4 of the 2nd method of adjusting the rotational speed of the stirring blade of a prior art, the 3rd method of adjusting the number of stirring blades which is a reference technique, and the 4th method of adjusting the binder addition position which is the present invention There are two kneading methods.

  The first kneading method as a conventional technique is, for example, adjusting the inclination of the apparatus as described above or adjusting the height by providing a weir capable of changing the height during operation in the apparatus. The amount of retention (the space factor) in the body kneading device is changed and adjusted. However, it cannot be applied if the increase / decrease range of the powder supply amount exceeds the range of the proper space factor of the kneading device. If the space factor in the kneading device 6 is changed to be lower than the appropriate range when the supply amount of the powder is reduced, the influence of the bottom surface of the kneading device is large and the kneading action by the stirring blade cannot be exhibited. Binder adheres and hinders operation. Also, if the space factor of the kneading device 6 is changed to be higher than the appropriate range when the powder processing amount is increased, powder exceeding the blade height is generated when stirring, and the kneading action of the stirring blade is sufficiently exhibited. It is because it is discharged without being able to.

The conventional method of adjusting the rotation speed of the stirring blade of the second kneading method can be changed during operation if an inverter motor is installed, but not only the equipment cost increases, but also the proper kneading state is achieved. May not be able to maintain. The stirring blade has an appropriate number of rotations depending on the size. If the number of rotations is too high, the centrifugal force will be excessive and the kneading action of the stirring blades cannot be exerted. If the number of rotations is too low, the stirring blades lift the powder. This is because the kneading action cannot be exhibited. As described above, since the appropriate rotation speed varies depending on the size and type of the kneading apparatus, the appropriate rotation speed is preferably determined in advance by experiments. Although the appropriate rotation speed of the stirring blade depends on the shape of the stirring blade, generally, the rotation speed at which the centrifugal force at the tip of the stirring blade is about 1/4 of the gravity is appropriate.
The technique of adjusting the number of stirring blades in the third kneading method, which is a reference technique, cannot be applied when continuously operating because the operation must be stopped and the stirring blade 9 of the kneading device 6 must be modified.

In the fourth kneading method according to the present invention, a signal of the amount of powder supplied from the powder supply device 3 is received by the feedforward control device 8 to calculate an appropriate length of the kneading unit 10, and to the binder addition nozzle 7. This is a kneading method that sends a signal to adjust the nozzle position and adjusts the length of the kneading section 10 in proportion to the amount of powder supplied. Therefore, it is an optimum kneading method for stabilizing the properties such as the particle size and bulk density of the kneaded product and the quality such as the yield and strength of the agglomerated product.
At that time, it is necessary to keep the space factor in the kneading apparatus 6 constant so as not to be a problem of the first kneading method. If the space factor in the kneading device 6 is out of the proper range, for example, the height of the weir 13 is changed to the upstream side of the discharge unit 12 (near the boundary between the kneading unit 10 and the discharge unit 12) of the kneading device. What is necessary is just to adjust so that the height of the weir 13 may be provided and the space factor may become constant.

If the space factor is too low, the kneading action of the stirring blades will not work and the binder will adhere to the shaft and blades. Conversely, if the space factor is too high, powder will pass through the device without being kneaded. .
For this reason, the constant space factor may be determined in advance by experiments or the like according to the specifications of the apparatus. For example, in the apparatus according to the embodiment of the present invention, a space factor of 80 to 90% is an appropriate space factor, and this is adjusted as a constant space factor.

  Here, the kneading method of the present invention is intended for dried powders that do not become pseudo particles and do not change properties such as particle size distribution and bulk density even when kneaded without adding a binder. Although the dried powder depends on the kind of the powder, generally, a powder having a water content of 5% by mass or less, preferably 2% by mass or less is desirable. This is because, when the kneading method is applied to powder that has not been dried, it is kneaded on the upstream side of the binder addition nozzle 7 to form pseudo particles, so that the powder properties such as particle size and bulk density change. In the above-mentioned dried powder, the powder properties do not change even when kneaded upstream of the binder addition nozzle 7, and the binder is dispersed in the powder by adding the binder and kneading to form pseudo particles. It is possible for the first time to change the physical properties.

  As a means for adjusting the position of the binder addition nozzle 7, the nozzle may be moved by using a flexible hose, a telescopic tube or the like, or a plurality of nozzles having different positions in the longitudinal direction of the kneading apparatus may be installed in advance by a valve or the like. You may select the position of the nozzle which actually adds a binder. However, although the number of stages in the longitudinal direction of multiple nozzles depends on the amount of increase / decrease in the amount of powder supplied, the number of stages is too small in the second and third stages, so four or more stages are required. It is preferable to maintain 5 or more stages. Moreover, since an installation cost and control cost increase when there are too many steps, 10 steps or less are preferable. If the kneading device 6 is an open system without a ceiling, the former (moving nozzle) is effective. If the kneading apparatus 6 is a closed system with a ceiling, the latter (multistage nozzle) is effective. By applying the powder kneading method of the present invention, even if the supply amount of the powder increases or decreases, the kneading state of the powder and the binder is kept in an appropriate range, properties such as the particle size and bulk density of the kneaded product, and It becomes possible to stabilize the quality of the agglomerate, such as yield and strength.

The addition position of the binder is within a certain range of the space factor, and the supply amount and the length of the kneading section when an appropriate kneading situation is obtained in advance (from the binder addition nozzle position of the kneading apparatus to the discharge section) The length of the kneading unit is selected, or the binder addition nozzles with different positions in the longitudinal direction of the kneading apparatus are selected or moved in the longitudinal direction so that the length of the kneading unit becomes the length corresponding to the supply amount. Move and control possible binder addition nozzles.
Normally, the standard position of the binder addition nozzle is set with respect to the average supply amount, and the shift amount from the standard position of the binder addition nozzle is proportional to the increase or decrease of the supply amount at each time point with respect to the average supply amount. And the position of the binder addition nozzle can be selected or moved in accordance with this.

Further, in order to stabilize the quality of the agglomerates when the supply amount of the powder increases or decreases, it is necessary to adjust the production method of the agglomerates by the roll agglomerator 14. The technique is described in Patent Document 3, but will be briefly described with reference to FIG.
A pair of rotating rolls 20 that are pressed by a hydraulic cylinder (not shown) at a predetermined pressure, the gap between the rolls continuously fluctuates so that the predetermined pressure is maintained, and the number of rotations can be adjusted; A roll agglomerator 14 provided above the pair of rotating rolls and provided with a powder feeder comprising a screw feeder 18 and its casing 19 is used. On the surface of the rotary roll, a cross-sectional shape perpendicular to the roll axis is V-shaped or wavy, and groove-shaped irregularities extending substantially parallel to the roll axis direction are formed. Powder is supplied and pressed onto the pair of rotating rolls 20, and the powder is agglomerated in a plate shape with the rotation of the rotating rolls. At that time, the rotational speed of the screw feeder is controlled so that the gap 21 between the pair of rotating rolls is constant, and in proportion to the rate of increase or decrease in the processing amount of the powder, Increase or decrease the screw feeder rotation speed. This technique makes it possible to keep the thickness of the agglomerate constant even when the amount of powder supplied is increased or decreased, and to stabilize the quality of the agglomerate, such as yield and strength.

  The powder kneading method and the powder agglomeration method of the present invention are effective for fine powder obtained by classifying coke pretreatment coal into fine powder and coarse particles using a fluidized bed drying classifier. Although it is effective for kneading before roll forming and subsequent agglomeration described in Patent Document 3 described above, it is not limited thereto, and various dry powders are kneaded and agglomerated with a binder. It is applicable when

Example 1
An example of the agglomeration test of pulverized coal in the coke pretreatment process is shown below. Similar to the flow shown in FIG. 1, a test was conducted in which the powder and the binder were kneaded by a kneading apparatus and then agglomerated by a roll agglomerator.
The powder is pulverized coal recovered by drying and classification in a fluidized bed drying classifier, and a powder having a mass ratio of particles of 0.3 mm or less in the pulverized coal of 70 to 90% was used. As the moisture of the pulverized coal, 1.5% by mass of dry powder was used. Moreover, in order to match temperature conditions with the actual machine using a fluidized bed drying classifier in the coke pretreatment process, pulverized coal was heated to 70 to 80 ° C. and used. The tar used as a by-product from the chamber-type coke oven was used as the binder, but for the purpose of cost reduction, a mixture of tar soot containing water and solids and crude tar before refining at a mass ratio of 50:50 was used. . The tar soot is a precipitate when the tar generated from the coke oven is statically separated and contains a large amount of moisture and solids, and is difficult to effectively use. The components of the tar meal were 5 to 20% moisture, 5 to 20% solid content, and 60 to 90% tar content by mass ratio. The crude tar is obtained by separating tar generated from a coke oven as a tar content by a stationary separation method, and it contains a little water and solids and is inexpensive because it is a pre-purification stage. The components of the crude tar were 0 to 5% moisture, 0 to 2% solid content, and 94 to 99% tar content by weight. Moreover, the addition ratio of the binder was adjusted according to the amount of pulverized coal supplied so that the external number was constant by 8% by mass with respect to the pulverized coal, and the temperature of the binder was also heated to 70 to 80 ° C.

  The schematic diagram of the kneading apparatus used for this test is shown in FIGS. (A) is a cross section perpendicular to the longitudinal direction of the kneading apparatus, (b) is a side cross section, and (c) is a plane cross section. The type of the kneading device is a biaxial horizontal kneader in which the shape of the stirring blade 9 is a fan shape and the feed direction and the return side are alternately arranged on the shaft (rotation shaft) 17. Is 20 mm, the diameter of the stirring blade 9 is 120 mm, the number of stirring blades is 9, the spacing between the stirring blades is 60 mm, the shape of the stirring blades is 140 °, the rotational speed is constant at 60 rpm, and the rotation direction of the two axes is As shown to (a) of FIG. 3, it is mutually opposite direction, and a cylinder is an open system without a ceiling. Moreover, the binder addition nozzle 7 uses one single pipe, is installed in the center part of the width direction (direction orthogonal to the longitudinal direction) of the kneading apparatus, is provided with a rail (not shown), and is manually set in the longitudinal direction. The structure can be moved easily. The test was performed by changing the amount of powder supplied to the kneading apparatus by 2 kg / min in the range of 2 to 20 kg / min, and adjusting the position of the binder addition nozzle in 10 stages according to the amount of powder supplied. Specifically, based on the length of the kneading part when the powder supply rate is 10 kg / min, the position of the binder addition nozzle is set upstream or downstream so that the length of the kneading part is proportional to the powder supply rate. Adjusted to the side. Further, the weir 13 is provided in the kneading apparatus in order to adjust the retention amount (space factor) of the powder in the kneading apparatus to 80 to 90%. However, in this apparatus, the weir 13 is not used. The space factor was stable at 80-90%.

The roll aggregator used in this test has a roll having a V-shaped cross section on the surface and a large number of grooves extending in the circumferential direction in the circumferential direction. The roll diameter is 224 mm and the roll is reduced. A roll agglomerator with a constant force of 1.5 t / cm was used, and the rotation speed of the agglomerator screw feeder was adjusted so that the gap between the rolls was 3.5 ± 0.1 mm. In addition, as described above, the agglomerates were produced by increasing / decreasing the number of rotations of the rotary roll and screw feeder in proportion to the rate of increase / decrease in the amount of powder supplied.
Under the above conditions, the powder and binder are supplied to the kneader and kneaded, and then agglomerated by a roll agglomerator, and the kneaded product particle size and bulk density, and the agglomerate yield and drop strength are evaluated as indices. did.
Note that the bulk density is determined by placing the kneaded material in a 1L beaker that has been ground beforehand and measuring the mass with a shovel. The density was calculated. In addition, the drop strength is about 1 kg of agglomerates of 1 mm or more (1 mm mesh screen or more), weighed, put in a bag, and offline according to the drop conditions (head, floor, order, number of times) when transporting the actual machine After dropping, the particles of 0.3 mm or more in the bag were weighed, and the ratio (mass ratio) was calculated.

  In addition, the particle size of the kneaded product was set to a mass ratio of particles of 0.3 mm or less in the kneaded product, and the target was set to 50% or less from the viewpoint of dust generation prevention. The bulk density of the kneaded product is the mass per unit volume of the kneaded product obtained by kneading pulverized coal and a binder with a kneading apparatus, and is preferably as high as possible. The yield of agglomerates is the mass proportion of agglomerates of 1 mm or more in the agglomerates, and the higher the better. The drop strength of the agglomerate is the mass ratio of particles of 0.3 mm or more after dropping during a drop test that simulates the drop conditions during actual transportation. The target is 80% or more from the viewpoint of dust generation and carryover prevention. It was.

FIG. 4 shows the result of evaluating the bulk density of the kneaded product and the mass ratio of particles of 0.3 mm or less in the kneaded product, and FIG. 5 shows the result of evaluating the drop strength and yield of the agglomerated product. In the figure, the powder supply amount ratio on the horizontal axis represents the ratio of increase / decrease in the powder supply amount when the supply amount is changed by 2 kg / min with the powder supply amount of 10 kg / min as the reference. Even if the powder supply ratio changes within a range of 10 to 0.2 to 2 (corresponding to 2 to 20 kg / min), the binder is moderately dispersed by adjusting the binder addition position to make pseudo particles. In addition, the mass ratio of particles of 0.3 mm or less in the kneaded product was set to 50% or less of the target, and the bulk density of the kneaded product could be secured to 0.7 kg / L or more. In addition, even when agglomerated, even if the powder supply ratio changes within the range of 0.2 to 2, by adjusting the binder addition position, the drop strength of the agglomerate is 80% or more of the target In addition, the yield of agglomerates can be secured at 90% or more.
In this test, the powder supply ratio was in the range of 0.2 to 2, but the binder addition ratio was kept constant, the amount of powder retained in the kneading apparatus was kept constant, and the stirring blade was rotated. If this method is used to keep the number constant and adjust the binder addition position according to the increase or decrease in the amount of powder supplied, even if the powder supply ratio exceeds the range of 0.2 to 2, that is, the powder Even if the processing amount is increased or decreased by 10 times or more, it is estimated that the same result as in this test will be obtained. Therefore, the properties of the kneaded material and the agglomerate are stabilized more than the target, and dust generation during transportation and charging is performed. And carryover can be suppressed.

(Example 2)
The same raw material as in Example 1 was used, and the same test apparatus as in Example 1 was used except for the position of the binder addition nozzle, and the same test as in Example 1 was performed. The position of the binder addition nozzle was adjusted in five stages, one skipping in Example 1.
FIG. 6 shows the result of evaluating the bulk density of the kneaded product and the mass ratio of particles of 0.3 mm or less in the kneaded product, and FIG. 7 shows the result of evaluating the drop strength and yield of the agglomerated product. Even if the powder supply amount ratio changes within a range of 10 to 0.2-2, by adjusting the binder addition position, the binder is moderately dispersed to form pseudo particles, and 0.3 mm or less in the kneaded product The mass ratio of the particles can be reduced to the target of 50% or less, and the bulk density of the kneaded product can be secured to 0.7 kg / L or more. In addition, even when agglomerated, even if the powder supply ratio changes within the range of 0.2 to 2, by adjusting the binder addition position, the drop strength of the agglomerate is 80% or more of the target In addition, the yield of agglomerates can be secured at 90% or more.

(Example 3)
The same raw material as in Example 1 was used, and the same test apparatus as in Example 1 was used except for the kneading apparatus, and the same test as in Example 1 was performed. As the kneading apparatus, a paddle mixer in which the stirring blade 9 of the horizontal kneader of Example 1 was modified to a paddle was used. The paddle has a length of 50 mm, a width of 15 mm, and the number of sheets is 18. The height of the weir 13 in the kneading apparatus is adjusted so that the powder space factor in the kneading apparatus is 80 to 90%, A test was conducted.
FIG. 8 shows the result of evaluating the bulk density of the kneaded product and the mass ratio of particles of 0.3 mm or less in the kneaded product, and FIG. 9 shows the result of evaluating the drop strength and yield of the agglomerated product. Even if the powder supply amount ratio changes within a range of 10 to 0.2-2, by adjusting the binder addition position, the binder is moderately dispersed to form pseudo particles, and 0.3 mm or less in the kneaded product The mass ratio of the particles can be reduced to the target of 50% or less, and the bulk density of the kneaded product can be secured to 0.7 kg / L or more. In addition, even when agglomerated, even if the powder supply ratio changes within the range of 0.2 to 2, by adjusting the binder addition position, the drop strength of the agglomerate is 80% or more of the target In addition, the yield of agglomerates can be secured at 90% or more.
In this test, the powder supply ratio was in the range of 0.2 to 2, but the binder addition ratio was kept constant, the amount of powder retained in the kneading apparatus was kept constant, and the stirring blade was rotated. If this method is used to keep the number constant and adjust the binder addition position according to the increase or decrease in the amount of powder supplied, even if the powder supply ratio exceeds the range of 0.2 to 2, that is, the powder Even if the processing amount is increased or decreased by 10 times or more, it is estimated that the same result as in this test will be obtained. Therefore, the properties of the kneaded material and the agglomerate are stabilized more than the target, and dust generation during transportation and charging is performed. And carryover can be suppressed.

(Comparative Example 1)
Using the same raw materials and test apparatus as in Example 1, the position of the binder addition nozzle of the kneading apparatus was fixed at the center of the part where the stirring blades were installed (longitudinal direction central part of the kneading part). Other conditions were the same as in Example 1.
FIG. 10 shows the result of evaluating the bulk density of the kneaded product and the mass ratio of particles of 0.3 mm or less in the kneaded product, and FIG. 11 shows the result of evaluating the drop strength and yield of the agglomerated product. If the powder supply amount ratio exceeds the range of 0.8 to 1.6 unless the binder addition position is adjusted when the powder supply amount ratio changes in the range of 0.2 to 2, The mass ratio of particles of 0.3 mm or less cannot be reduced to 50% or less of the target, the drop strength of the agglomerate cannot be increased to 80% or more of the target, and the bulk density of the kneaded product and the yield of the agglomerate are reduced did.
Conversely, when the nozzle position is fixed, the range of the powder supply amount ratio that can stabilize the properties of the kneaded material and the agglomerated material more than the target was about 0.8 to 1.6. In other words, when the powder supply amount greatly increases or decreases twice or more, it is estimated that the binder addition position needs to be adjusted.

(Comparative Example 2)
Next, the same raw materials and test equipment as in Example 3 were used, the height of the weir was adjusted to be proportional to the supply amount of powder, the retention amount (space factor) was forcibly changed, and the other The test was conducted in the same manner as in Example 1. As a result, when the space factor becomes 50% or less, the binder and the powder adhere to the shaft and the stirring blade, impede the flow of the powder, and the kneading apparatus cannot be operated, and the test must be stopped. lost.

(Comparative Example 3)
Further, using the same raw materials and test apparatus as in Example 3, following the method disclosed in Patent Document 2, the space factor of the powder in the kneading apparatus is adjusted by adjusting the moving speed of the fine powder in the kneading machine. The number of rotations of the paddle was adjusted so as to be constant in the range of 80 to 90%, and the same test as in Example 3 was performed. At that time, the test was conducted by removing the weir in the kneading apparatus. In addition, since the method disclosed in Patent Document 2 treats powder at 100 ° C. or higher, crude tar and tar soot before purification containing water boiled, so it was thought that it could not be used as a binder. In this test, in order to process a powder of 70 to 80 ° C., an inexpensive mixture of crude tar and tar soot was used as a binder.
FIG. 12 shows the result of evaluating the bulk density of the kneaded product and the mass ratio of particles of 0.3 mm or less in the kneaded product, and FIG. 13 shows the result of evaluating the drop strength and yield of the agglomerated product. When the powder supply ratio is in a range other than 0.4 to 0.8, the mass ratio of particles of 0.3 mm or less in the kneaded product cannot be reduced to 50% or less of the target, and the drop strength of the agglomerate is also the target. In addition to being 80% or more, the bulk density of the kneaded product and the yield of the agglomerated product were also reduced. If the supply amount of powder greatly increases or decreases as in this case, even if the space factor in the kneading device is adjusted with the movement speed of the fine powder (paddle rotation speed), an appropriate kneading state may not be ensured. It is estimated to be.

1 Powder hopper 2, 2 'level detector 3 Powder supply device (rotary valve)
4 Binder hopper 5 Binder supply device (pump)
6 Kneading equipment (kneading machine)
6a cylinder 7 binder addition nozzle 8 feedforward control device 9 stirring blade 10 kneading part 11 supply part 12 discharge part 13 weir 14 roll agglomeration machine 15 opening part 16 screw 17 rotating shaft 18 screw feeder 19 casing 20 roll 21 between rolls Gap M drive unit (motor)

Claims (5)

The pulverized coal obtained by classifying the coke pretreatment coal into fine powder and coarse particles in a fluidized bed drying classifier is supplied to a horizontally long kneading apparatus with a built-in stirring blade, and a binder is added to the kneading apparatus. A powder kneading method for kneading,
The binder contains a crude tar before refining tar containing moisture and solids,
While keeping the rotation speed of the stirring blade built in the kneading device constant, and controlling the amount of residence of the kneaded material in the kneading device to be constant,
And the addition position of the binder is variable in the longitudinal direction of the kneading apparatus, and when the supply amount of the powder is increased or decreased, the addition ratio of the binder to the pulverized coal is before and after the increase or decrease in the supply amount of the powder. The amount of the binder added is adjusted to be constant at the same time, and the binder addition position is adjusted to the upstream side of the kneading device if the powder supply amount is increased. A powder kneading method, wherein the powder is changed in proportion to an increase / decrease rate of the supply amount of the powder on the downstream side of the kneading apparatus. Means for varying the feed point of the binder in the longitudinal direction of the kneading device, in claim 1, characterized in that the binder additive nozzle is due to the provision of the mechanism for moving in a longitudinal direction of the kneading apparatus The powder kneading method described. The means for changing the addition position of the binder in the longitudinal direction of the kneading apparatus is provided with the binder addition nozzle being changed in four or more stages in the longitudinal direction of the kneading apparatus, and switching the binder addition nozzle for adding the binder. The powder kneading method according to claim 1, wherein: A powder agglomeration method, wherein the powder kneaded by the powder kneading method according to any one of claims 1 to 3 is charged into a roll agglomerator and agglomerated in a plate shape. A powder kneading apparatus for use in the powder kneading method according to any one of claims 1 to 3 , wherein an upper part is opened or sealed, and a cylindrical body extending in a horizontal direction is provided upstream of the cylindrical body. An installed powder supply unit, a powder discharge unit installed on the downstream side of the cylinder, and a rotating shaft extending horizontally in the cylinder between the powder supply unit and the powder discharge unit A kneading part having an attached stirring blade, a driving device for rotating a rotating shaft to which the stirring blade is attached, and a binder for supplying the kneading part with a binder containing a crude tar before refining tar containing water and solids. An addition nozzle, a powder supply device for supplying powder to the powder supply unit, and a binder supply device for supplying binder to the binder addition nozzle, and when the supply amount of powder increases or decreases, The amount of powder retained in the kneader is constant. And a feedforward control device for adjusting the amount of binder added so that the addition ratio of the binder to the powder is constant before and after the supply amount increase and decrease of the powder, and The binder adding nozzle has a mechanism that is provided in the longitudinal direction of the kneading apparatus and that can switch nozzles for charging the binder, or has a mechanism that can move in the longitudinal direction of the kneading apparatus. When the supply amount of the powder is increased or decreased, the powder is supplied to the upstream side of the kneading device, and if the supply amount of the powder is reduced, the powder is supplied to the downstream side of the kneading device. The powder kneading apparatus characterized in that the addition position in the longitudinal direction of the binder addition nozzle can be changed in proportion to the increase / decrease rate of the supply amount of the body.

Images