JP2002253943A - Method and apparatus for granulating powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for granulating powder, by which powder having high liquid absorptivity or powder containing a lot of fine particles can be granulated excellently by a small amount of a binder. SOLUTION: Powder is thrown in a granulator 1 having an inner blade 3 and an outer blade 4, the blades 3 and 4 are rotated, a prescribed amount of water is supplied to the granulator 1 all at once through a water supplying pipe 5 and the binder is supplied through a binder supplying pipe 6 and granulation is then started. According to this granulating method, the binder is dispersed in the water in a short time and adhered to the surface of the powder excellently without being absorbed inside the powder since the surface of the powder is made wet even when the powder has very high water absorptivity. Fine particles can be restrained from being adhered to the powder since they are restrained from floating by the supplied water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a powder granulating apparatus,
More specifically, the present invention relates to a powder granulating method and a powder granulating apparatus used for granulating a powder having a high liquid absorbency or a fine powder.

[0002]

2. Description of the Related Art Conventionally, a stirring granulation method has been known as a method for granulating powder. In the stirring granulation type granulation,
For example, using a super mixer (Henschel mixer) equipped with high-speed horizontal rotating blades at the bottom of the casing,
First, after the powder is put into this super mixer (Henschel mixer), the high-speed horizontal rotating blades are driven to rotate and a binder is supplied to grow the powder while raising and lowering the powder along the wall surface of the casing. To granulate.

[0003]

However, for example, when the powder is an inorganic powder having a very high liquid absorbability, the binder is supplied from the surface of the powder even if the binder is supplied. Therefore, it is necessary to supply a large amount of binder to adhere to the surface of the powder so that the binding force of the binder is developed.

Further, when a large amount of fine powder is contained in the powder, even if a binder is attached to the surface of the powder, a large amount of the fine powder floating in the air adheres to the powder. In fact, since the binding force of the binder is reduced, the binder must be supplied until the suspended fine powder is completely removed, and a larger amount of the binder is required.

[0005] When a large amount of binder is supplied in such a manner, the obtained granules become unnecessarily sticky, causing a problem that quality is deteriorated and handling is inconvenient.

The present invention has been made in view of such circumstances, and an object of the present invention is to granulate a powder having a high liquid absorbency or a powder containing a large amount of fine powder with a small amount of a binder. It is an object of the present invention to provide a powder granulating method and a powder granulating apparatus which can perform the above method.

[0007]

According to a first aspect of the present invention, there is provided a method of granulating a powder by a granulating apparatus having a stirring means, wherein the powder is granulated. The method is characterized by comprising a step of charging the granulating apparatus and a step of first adding water to the granulating apparatus and then adding a binder.

According to such a method, even if the powder has a very high liquid absorbability, the surface of the powder is wetted by the supply of water.
When the binder is supplied, the binder is dispersed in a short period of time and adheres well to the surface of the powder without being absorbed inside the powder. Further, even when the powder contains a large amount of fine powder, the supply of water suppresses the floating of the fine powder, so that the adhesion of the fine powder to the powder can be suppressed, and the binding of the binder can be suppressed. A decrease in force can be prevented.

The invention described in claim 2 is the first invention.
In the invention described in (1), a predetermined amount of water is added all at once.

When a predetermined amount of water is added at a time, the surface of the powder can be wetted before the water is absorbed into the inside of the powder. That is, the absorption near the surface of the powder becomes supersaturated. Therefore, the wettability of the surface and the durability thereof can be further enhanced. When a large amount of fine powder is contained in the powder, floating of the fine powder can be suppressed at once by adding a predetermined amount of water.

According to a third aspect of the present invention, there is provided an apparatus for granulating a powder, comprising: a casing for receiving the powder; a stirring means provided in the casing for stirring the powder; A water supply means for supplying water into the casing, and a binder supply means for supplying a binder into the casing, for supplying water by the water supply means, and then supplying a binder by the binder supply means. It is characterized by having supply control means.

According to such a configuration, since the supply control means supplies the binder with the binder supply means after supplying the water with the water supply means, for example, even if the powder has a very high liquid absorbability, First, when the water is supplied, the surface of the powder is wetted with the water, and then, when the binder is supplied, the binder is dispersed in a short time and is absorbed into the powder. And adheres well to the surface of the powder. Further, even when the powder contains a large amount of fine powder, the supply of water suppresses the floating of the fine powder, so that the adhesion of the fine powder to the powder can be suppressed, and the binding of the binder can be suppressed. A decrease in force can be prevented.

The invention described in claim 4 is the same as the claim 3.
In the invention described in (1), the supply control means controls the water supply means so as to add a predetermined amount of water at a time.

According to such a configuration, the water supply means adds a predetermined amount of water at a time under the control of the supply control means.
The surface can be wetted before water is absorbed into the inside of the powder, that is, the absorption near the surface of the powder can be supersaturated, and the wettability of the surface and its sustainability Properties can be further enhanced. When a large amount of fine powder is contained in the powder, floating of the fine powder can be suppressed at once by adding a predetermined amount of water.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram showing one embodiment of a powder granulating apparatus according to the present invention.

In FIG. 1, a granulating apparatus 1 comprises a casing 2 for receiving powder and an inner blade 3 as a stirring means.
And an outer blade 4, a water supply pipe 5 as water supply means, and a binder supply pipe 6 as binder supply means.

The casing 2 is formed of a container having a substantially rectangular cross section. An upper portion of the casing 2 is provided with a charging hopper 7 for charging powder into the casing 2, and a lower portion thereof is formed in the casing 2. A discharge pipe 8 for discharging the granulated granules is provided.

The charging hopper 7 has a substantially cylindrical shape, a lower part of which is formed in a funnel shape, and a charging port 9 for charging powder is formed at a lower end communicating with the casing 2. I have. The input port 9 is provided with an input gate 10 for opening and closing the input port 9. The input gate 10 includes a slide gate 11 for opening or closing the input port 9 and an air cylinder 12 for opening and closing the slide gate 11.

The discharge pipe 8 has a cylindrical shape extending obliquely downward, and a discharge port 13 for discharging powder is formed at the upper end communicating with the inside of the casing 2. The discharge port 13 is provided with a discharge gate 14 for opening and closing the discharge port 13. The discharge gate 14 includes a slide gate 15 for opening or closing the discharge port 13 and an air cylinder 16 for opening and closing the slide gate 15.
And

The granulating apparatus 1 is provided with an air compressor 35.
5, the air cylinder 12 of the input gate 10 is connected to the input valve 3
9, and the air cylinder 16 of the discharge gate 14 is connected via a discharge valve 40.
With the air compressor 35 operating, the injection valve 39
, The air cylinder 12 of the input gate 10 is driven forward and backward, whereby the slide gate 11 is opened and closed, whereby a predetermined amount of powder is supplied into the casing 2 for each batch. . Also,
With the air compressor 35 operating, the discharge valve 40
Is opened and closed, the air cylinder 16 of the discharge gate 14 is driven forward and backward, whereby the slide gate 15 is opened and closed. Is discharged.

A bearing member 17 is provided below the bottom of the casing 2. The bearing member 17 includes an inner bearing 18 for bearing and supporting an inner blade shaft 20 described later, and an outer bearing 19 provided on an outer periphery of the inner bearing 18 and bearing and supporting an outer blade shaft 25 described later.

The inner blade 3 has an inner blade shaft 20 rotatably supported by an inner bearing 18 at the center of the bottom of the casing 2.
And a blade member 22 provided at the upper end of the inner blade shaft 20.
And an inner blade side pulley 2 provided at a lower end of the inner blade shaft 20.
3 is provided. The blade member 22 includes a plurality of inner rotary blades 24 extending radially outward.

The outer blade 4 has an inner blade shaft 20 therein at the center of the bottom of the casing 2 and the outer bearing 1.
9 and a plurality of outer rotary blades 26 provided at the upper end of the outer blade shaft 25.
And an outer blade side pulley 2 provided at a lower end of the outer blade shaft 25.
7 is provided. The outer rotary blade 26 is formed so as to extend radially outward from the outer blade shaft 25 and to extend upward along the side wall of the casing 2.

The inner blade 3 and the outer blade 4
Are configured to be driven to rotate independently of each other, and more specifically, configured to rotate in the same direction with a peripheral speed difference or to rotate in opposite directions. When rotating in the same direction with a peripheral speed difference, the rotation speed of the inner blade 3 is 150 to 400 times / mi.
n, it is preferable to rotate the outer blade 4 so that the rotation speed of the outer blade 4 becomes 20 to 100 times / min. When rotating in the opposite direction, the inner blade 3 and the outer blade 4 are rotated at a rotation speed of 20 to 400. The motor may be driven to rotate at the same speed at times / min, or may be driven to rotate at the above-described rotational speed with a peripheral speed difference therebetween.

The granulating apparatus 1 is provided with a prime mover 32 as a driving means. The prime mover 32 allows the inner blade side pulley 23 to move the inner blade side endless belt 3.
3 and the outer blade side pulley 2
7 is configured to be rotationally driven via an outer blade side endless belt 34.

The water supply pipe 5 and the binder supply pipe 6
Is configured such that an open end thereof is disposed above the casing 2 so that water and a binder can be supplied into the casing 2. A water tank 29 for storing water is connected to the water supply pipe 5 via a water supply valve 28, and the binder supply pipe 6 is connected to the binder supply valve 3.
A binder tank 31 for storing a binder is connected via a valve 0. A predetermined amount of water is supplied by opening and closing the water supply valve 28, and a predetermined amount of binder is supplied by opening and closing the binder supply valve 30. It is configured to be able to. The binder stored in the binder tank 31 is a binder for binding the powder to each other, and for example, a known viscous liquid such as dextrin, carboxymethylcellulose, methylcellulose, and water glass is used.

As shown in FIG. 1, a control system of the granulating apparatus 1 includes a CPU 36, a motor 32, an air compressor 3
5, the water supply valve 28, the binder supply valve 30, the input valve 39, and the discharge valve 40 are connected to each other.

The CPU 36 executes an operation for controlling each unit, and includes a ROM 37 and a RAM 38.
The ROM 37 stores a granulation program as a supply control means for executing a granulation process in the granulator 1. Further, the RAM 38 stores a temporary numerical value for executing the supply program.

In the granulating apparatus 1, a granulating program is executed so that, at the time of granulation, a predetermined amount of water is first added at once, and then granulation is performed while adding a binder.

That is, such a granulation process is started when a powder is charged from a charging hopper 7 as shown in FIG. At the start of the supply process, input gate 1
0 is opened to put the charging port 9 in the open state, the powder is charged into the casing 2, and the motor 32 is driven to rotate the inner blade 3 and the outer blade 4 at high speed. Then, the powder charged into the casing 2 starts to rotate in the shape of a figure “8” between the inner blade 3 and the outer blade 4, so that the stirring of the powder becomes a certain steady state (the prime mover 32). 3-4 seconds after the start of the
8 is opened to supply a fixed amount of water into the casing 2 at a time. The amount of water to be supplied is appropriately determined depending on the type of powder and the water absorption. For example, for 5 kg of powder,
It is about 0.1 to 10 L, preferably about 0.5 to 1.5 L. It is preferable that the supply of water be performed all at once in a short time (1-2 seconds). Next, after a predetermined time has elapsed after the closing operation of the water suction valve 28, the binder supply valve 30 is opened to supply a predetermined amount of binder. The time from the closing operation of the water absorption valve 28 to the opening operation of the binder supply valve 30 is appropriately determined depending on the type and amount of the powder. While water is not absorbed into the interior from the surface), for example 1 to 10 seconds, preferably 2
About 7 seconds. The amount of the binder supplied is, for example, 0.1 to 5 times the amount of water, preferably 0.1 to 5 times the amount of water.
It is about 5 to 2 times. Then, when the supply of the predetermined amount of the binder is completed, the binder supply valve 30 is closed, and thereafter, when the powder has grown to the predetermined particle size in a dumpling shape, the operation of the motor 32 is stopped. At the same time, the discharge gate 14 is opened, the discharge port 8 is opened, and the granulated material is discharged, thereby completing the granulation process.

According to such a granulation treatment, even if the powder has a very high water absorption, first, a predetermined amount of water is supplied from the water absorption pipe 5 so that the surface of the powder is made of water. Then, when the binder is supplied from the binder supply pipe 6, the binder is dispersed in a short time and adheres well to the surface of the powder without being absorbed inside the powder. Further, even when the powder contains a large amount of fine powder, the supply of water suppresses the floating of the fine powder, so that the adhesion of the fine powder to the powder can be suppressed, and the binding of the binder can be suppressed. A decrease in force can be prevented. Therefore, even if a large amount of binder is not supplied from the binder supply pipe 6, the powder can be satisfactorily granulated, and low-cost and efficient granulation can be achieved. Further, when the granulation is performed in this manner, a granulated product having low tackiness, good quality, and excellent handleability can be obtained.

Further, in this granulation treatment, since a predetermined amount of water is added at once from the water supply pipe 5, the surface of the powder can be wetted before the water is absorbed into the inside of the powder. In addition, the superabsorptivity of the powder in the vicinity of the surface can be brought into a supersaturated state, and the wettability of the surface and its persistence can be further enhanced. Also, by adding a predetermined amount of water at once, floating of the fine powder can be suppressed at once. Therefore, the amount of the binder to be supplied can be reduced, and more efficient and more efficient granulation can be achieved at a lower cost, and a granulated material having less tackiness, good quality and excellent handleability can be obtained. Can be.

Therefore, such a granulating apparatus 1 can favorably granulate a powder having a very high water absorption and a large amount of fine powder, and more specifically, a waste material of a gypsum board. It can be suitably used for granulation of inorganic powders such as, for example, and granulation of organic powders such as powder coating of resin pellets. The powder is not particularly limited, but is, for example, a spherical or angular powder having a size (maximum length) of usually 1 to 500 μm, preferably 20 to 200 μm. It may be a granular material containing 20 to 80% by weight of a spherical or angular granular material having a size (maximum length) of 10 mm.

In the above embodiment, the granulating apparatus 1 having the inner blades 3 and the outer blades 4 is used. However, in the present invention, there is no particular limitation as long as the stirring granulation method is used. A super mixer (Henschel mixer), an Erich mixer, a horizontal axis rotating blade type granulator or the like may be used.

Further, in the above embodiment, the water and the binder are supplied by opening and closing the water supply valve 28 and the binder supply valve 30, but instead of the water supply valve 28 and the binder supply valve 30, A water supply pump and a binder supply pump may be used. In addition, instead of the water tank 29, a water pipe is connected to the water supply pipe 5,
Water may be supplied by tap water pressure.

[0036]

As described above, according to the first aspect of the present invention, the powder can be satisfactorily granulated without supplying a large amount of the binder, and the powder can be efficiently formed at low cost. Grains can be achieved. Further, when the granulation is performed in this manner, a granulated product having low tackiness, good quality, and excellent handleability can be obtained.

According to the second aspect of the present invention, the supply amount of the binder can be further reduced, so that more efficient and more efficient granulation can be achieved. In addition, it is possible to obtain a granulated material having less tackiness, good quality, and excellent handleability.

According to the third aspect of the invention, the powder can be satisfactorily granulated without supplying a large amount of binder, and efficient granulation at low cost can be achieved. Further, when the granulation is performed in this manner, a granulated product having low tackiness, good quality, and excellent handleability can be obtained.

According to the fourth aspect of the present invention, the supply amount of the binder can be further reduced, so that more efficient and more efficient granulation can be achieved. In addition, it is possible to obtain a granulated material having less tackiness, good quality, and excellent handleability.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a powder granulating apparatus of the present invention.

FIG. 2 is a timing chart showing the operation timing of each part in the granulation processing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Granulator 3 Inner blade 4 Outer blade 5 Water supply pipe 6 Binder supply pipe 36 CPU

Claims (4)

[Claims] 1. A method of granulating a powder by a granulating device provided with a stirring means, comprising: adding water to the granulating device, and first adding water to the granulating device; A method for granulating a powder, comprising a step of adding a binder. 2. The method according to claim 1, wherein a predetermined amount of water is added at a time. 3. A casing for receiving the powder, a stirring means provided in the casing for stirring the powder, a water supply means for supplying water into the casing, and a binder supplied into the casing. And a supply control means for supplying a binder by the binder supply means after supplying water by the water supply means. . 4. The water supply control means controls the water supply means so as to add a predetermined amount of water at a time.
An apparatus for granulating a powder according to claim 3.