WO2013111431A2

WO2013111431A2 - Powder dispersion apparatus and fine powder generation method

Info

Publication number: WO2013111431A2
Application number: PCT/JP2012/079881
Authority: WO
Inventors: Tsutomu Ishizaki; Tadayoshi ARAKAWA; Keijiro Fujita; Tsunemoto Kuriyagawa
Original assignee: Kabushiki Kaisha Sangi
Priority date: 2012-01-24
Filing date: 2012-11-13
Publication date: 2013-08-01
Also published as: WO2013111431A3; JP2013150949A; JP5831857B2

Abstract

The conventional methods are effective for powder with low-aggregability, however, it is difficult to inhibit powder aggregation of the powder with high-aggregability. An objective of the present invention is to provide a powder dispersion apparatus for inducting powder and dispersing the powder by gas jet, comprising a powder-processing container, where an internal diameter of a lower portion of the container is gradually reduced downwardly; a gas jet orifice for the gas jet toward a bottom surface of the powder-processing container; and an outlet for extracting the powder, having been dispersed and blown upward by the gas jet, from the powder-processing container.

Description

DESCRIPTION

POWDER DISPERSION APPARATUS AND FINE POWDER GENERATION METHOD

Field of the Invention

[0001 ]

The present invention relates to a technology for a powder dispersion apparatus and a fine powder generation method.

Background Art

[0002]

When using fine powder as an ingredient of a medicine, a food or a toner in manufacturing , in order to keep homogeneity and uniformity, it is preferable to supply the fine powder in a state of uniformed primary particles. However, fine particles generally have aggregability and easily form an aggregate, so that it is difficult to make a homogeneous dispersion of powder. Therefore, in the field of handling powder, as it is important to achieve the homogeneous dispersion, various methods have been examined.

[0003]

For example, in Japanese Unexamined Patent Application Publication No. 201 1 -1 10512, a powder dispersion apparatus, where powder aggregate is dispersed by shear force of airflow caused by gas jets to the powder flowing toward the lower exhaust along with the surface of a slope, is disclosed . Moreover, in Japanese Unexamined Patent Application Publication No. 2007-75681 , a powder dispersion apparatus, where powder aggregate is dispersed by causing powder to fall from an inlet and to collide with a conical member, is disclosed.

Related Art Documents Patent Documents

[0004]

Patent Document 1 : Japanese Unexamined Patent Application Publication No. 201 1 -1 10512

Patent Document 2: Japanese Unexamined Patent

Application Publication No. 2007-75681

Outline of the Invention

Problems that the Invention Tries to Solve

[0005]

However, in the conventional methods, there are deficiencies that the powder aggregates are generated through contact between powder particles on the surface of the slope or the conical member for collision, the aggregates flow toward the lower outlet due to the gravitational force, and are exhausted. Therefore, although the conventional methods are effective for powder with low-aggregability, it is difficult to supply the homogeneously-dispersed primary particle of the powder with high-aggregability.

Means for Solving the Problems

[0006]

In order to solve the above deficiencies, an aspect of the present invention provides a powder dispersion apparatus for inducting powder and dispersing the powder by gas jet, comprising a powder-processing container, where an internal diameter of a lower portion of the container tapers downwardly; a gas jet orifice for the gas jet toward a bottom surface of the powder-processing container; and an outlet for extracting the powder, having been dispersed and blown upward by the gas jet, from the powder-processing container. [0007]

Moreover, an aspect of the present invention provides a powder generation method, comprising storing powder in a bottom portion of a powder-processing container, where an internal diameter of a lower portion of the container tapers downwardly; jetting gas from a gas jet orifice toward a bottom surface of the powder-processing container; and extracting the powder, having been dispersed and blown upward by the gas jet, from the powder-processing container.

Effects of the Invention

[0008]

According to the present invention having the above configuration, it is possible to extract the powder, which has been dispersed and blown upward by the gas jet, from the outlet placed in the upper portion of the powder-processing container, thereby homogeneously dispersing the powder with high-aggregability.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]

Fig. 1 is a schematic view showing a configuration of a powder dispersion apparatus of a first embodiment.

Fig. 2 is a perspective view showing a powder-processing container disassembled from the powder dispersion apparatus of Fig. 1.

Fig. 3 is a view showing another example of the powder-processing container of the first embodiment.

Fig. 4 is a view showing another example of a gas jet orifice. Fig. 5 is a view showing another example of positional relation between a gas induction and an outlet. Fig. 6 is a view showing gas jet from the gas jet orifice to the lowest portion of the powder-processing container.

Fig . 7 is a view showing the powder-processing container provided with a powder inlet.

Fig . 8 is a view showing the powder-processing container provided with a knocker on an external wall.

Fig. 9 is a flowchart of a fine powder generation method of the first embod iment.

Fig . 1 0 is a schematic view showing a configuration of a powder d ispersion apparatus of a second embodiment.

Fig . 1 1 is a perspective view showing a powder-processing container d isassembled from the powder dispersion apparatus of Fig. 1 0.

Fig. 1 2 is a view showing gas jet from the gas jet orifice to the lowest portion of the powder-processing container.

Fig . 1 3 is a view showing an example of a configuration where a powder flow control pole also functions as a gas supply tube.

Fig . 14 is a view showing an example where a lower portion of the powder flow control pole has approximately inverted conical shape.

Fig . 1 5 is a view showing that a plurality of gas jet orifices placed on the side of the lower portion of the powder flow control pole.

DETAILED DESCRIPTION OF THE INVENTION

[001 0]

Hereinafter, descriptions of embodiments of the powder dispersion apparatus of the present invention will be provided . The first embodiment will describe Claims 1 and 5. The second embodiment will describe Claims 2, 3 and 4. The present invention is not to be limited to the above embodiments and able to be embodied in various forms without departing from the scope thereof.

[001 1 ]

<<First Embodiment»

[0012]

< Configuration of First Embodiment

Fig. 1 is a schematic view showing a configuration of a powder dispersion apparatus of a first embodiment. A 'a powder dispersion apparatus' 100 is an apparatus for inducting powder and dispersing the powder by gas jet, and comprises a 'powder-processing container' 1 , where an internal diameter of a lower portion of the container tapers downwardly, a 'gas jet orifice' 1 1 for the gas jet toward a bottom surface of the powder-processing container, and an 'outlet' 21 for extracting the powder, having been dispersed and blown upward by the gas jet, from the powder-processing container. Hereinafter, descriptions of the respective components are provided.

[0013]

(Powder-processing container)

Fig. 2 is a perspective view showing a powder-processing container disassembled from the powder dispersion apparatus of Fig. 1 . In Fig. 2, a 'container cap' 31 provided with a 'gas inlet' 12 and the Outlet' 21 can be fit in the 'powder-processing container' 1 , and the 'powder-processing container' 1 and the 'container cap' 31 are easily assembled or disassembled. A 'gas induction tube' 13 connects the 'gas inlet' 12 and the 'gas jet orifice' 1 1 . When inducting the powder into the powder-processing container, the 'powder-processing container' 1 and the 'container cap' 31 are d isassembled , and the powder is inducted from an 'orifice' 2 of the 'powder-processing container' 1 , and after completion of ind uction , the 'powder-processing container' 1 is assembled with other parts.

[0014]

The 'powder-processing container' 1 is a container where an internal d iameter of a lower portion of the container tapers downward ly. The lower portion of the powder-processing container is for storing the powder d ispersed by gas jet, and for receiving the gas jet from the upper portion . As the shape of the lower portion where the internal diameter tapers downwardly, the round-bottom shape as shown in Figs. 1 and 2 are applicable. Fig . 3 is a view showing another example of the powder-processing container of the first embod iment. I n Fig . 3 , the lower portion has an inverted truncated conical shape. Thus, by g rad ually red ucing the internal d iameter of the lower portion downwardly, gas is d ispersed in the lower portion when receiving the gas jet from the upper portion , thereby generating isotropic upward flow.

[001 5]

(Gas jet orifice)

The 'gas jet orifice' 1 1 is for the gas jet toward a bottom surface of the powder-processing container. The gas is carried through the 'gas ind uction tube' from the 'gas inlet' 1 2 to the 'gas jet orifice' 1 1 . The shape of the gas induction tube is not limited , and a narrow tube as shown in Fig . 1 may be utilized . The d iameter of the 'gas jet orifice' 1 1 may be approximately the same as the diameter of 'gas induction tube' 1 3, or as shown in Fig . 4, may be narrow than that of the 'gas ind uction tube' 1 3, thereby increasing pressure and velocity of gas jet. As the inlet diameter increases, it is possible to acquire higher pressure and velocity of the gas jet. Meanwhile, the amount and area of the gas jet become smaller, so that it is preferable to appropriately select the diameter according to the powder amount, and to make the diameter of the gas jet orifice variable.

[0016]

Moreover, the position of the gas jet orifice is not limited, and any position enabling the gas jet to blow toward the lower portion of the powder-processing container is applicable, and it is preferable to provide the gas jet orifice at the lowest portion of the gas induction tube, such that the position is near the powder storage area. Moreover, the gas jet is blown immediately below from the gas jet orifice, placed at the lowest portion of the gas induction tube, so that it is possible to create the isotropic upward flow at the bottom of the powder-processing container. The isotropic upward flow can blow the powder upward , and also disperse the powder aggregate. Moreover, the gas jet orifice may be placed on the side surface near the lowest portion of the gas induction tube. The gas jet orifice placed on the side surface near the lowest portion of the gas induction tube can generate a swirling flow. The swirling flow can disperse the powder aggregate by shearing force. Note that the direction of the gas jet from the gas jet orifice is not limited to the direction toward the lowest portion of the powder-processing container, and may be carried out in another direction.

[0017]

(Outlet)

The Outlet' 21 is for extracting the powder, having been dispersed and blown upward by the gas jet, from the 'powder-processing container' 1 . The outlet is placed at a higher position than that of the gas jet orifice, so that the powder dispersed and blown upward by the gas jet is exhausted from the outlet. Note that the outlet is placed near the upper portion, thereby enabling a reduction of the powder aggregate extracted from the outlet. Moreover, although the 'gas inlet' 12 is placed at the higher position than the 'outlet' 21 in Fig. 1 and 2, the 'gas inlet' 12 may be placed at a higher position than the Outlet' 21 as shown in Fig. 5. Moreover, a single number of the outlet or a plurality of outlets may be placed, and it is possible to appropriately select the number thereof as usage. For example, it is possible to open any one or more of the plurality of outlets according to tolerance of powder aggregate, thereby extracting the powder contained in the gas flow. Moreover, some outlets placed at positions of different heights are simultaneously opened, so that it is possible to exhaust a plurality of flows of different fine powder densities. Note that the powder may be exhausted from the outlet without change as usage, or may be transported to another apparatus through a transport tube.

[0018]

Fig. 6 is a view showing gas jet from the gas jet orifice to the lowest portion of the powder-processing container. The pressure gas inducted from the 'gas inlet' 12 is transported to the 'gas jet orifice' 1 1 through the 'gas induction tube' 13. The gas jet from the 'gas jet orifice' 1 1 disperses and blows upward the powder stored in the lowest portion of the powder producing container. Note since the powder aggregate has a smaller mass than the fine powder, less amount of powder aggregate is blown upward . Moreover, as described above, the powder aggregate is easily dispersed by the gas jet from the 'gas jet orifice' 1 1 , and becomes fine powder.

[0019]

As to the jet velocity of the gas jet from the gas jet orifice, depending on the size of the powder processing container, the average mass of the fine powder, and the position of the outlet, it is preferable to adjust the velocity to 1 - 500 m/s, and more preferable, 100 - 400 m/s. For example, the lower jet velocity reduces the exhaust velocity of the fine powder, and blows fewer amounts of powder aggregates upward , so that it is possible to reduce the amount of the powder aggregates extracted from the outlet. Meanwhile, although the higher jet velocity blows slightly more amounts of powder aggregates upward , it is possible to increase the exhaust velocity of the fine powder. Note that the gas jet velocity may not be constant, and may be varied on a periodic basis, or may be intermittently executed. The gas inducted into the gas induction tube for the gas jet from the gas jet orifice to the powder processing container has a higher pressure than the gas in the powder processing container, and is supplied to the gas inlet by a pressure gas supplier such as a pump. The larger pressure difference between the internal pressures of the powder processing container and the gas induction tube makes the gas jet velocity higher. Moreover, by providing the gas inlet with a valve, it is possible to induct or cut off the pressure gas as necessary. The type of the gas is not limited, and it is preferable to select the gas having low responsiveness to the powder.

[0020]

Note that the powder induction is not limited to the example of Fig. 2 showing the induction from the Orifice' 2 of the 'powder-processing container' 1 . For example, it is possible to provide a portion of the powder processing container with a powder inlet, thereby continuously inducting the powder without disassembling the powder processing container. Fig. 7 is a view showing the powder-processing container provided with the powder inlet. In Fig. 7, the 'powder inlet' 22 is placed at the slightly upper position in the lower portion of the 'powder-processing container' 1 . The induction of the powder may be continuously or intermittently carried out. Moreover, the powder inlet may be placed at the lower portion, middle portion or upper portion of the powder-processing container.

[0021 ]

Moreover, in order to prevent the powder adherence to the internal wall of the powder processing container, it is possible to provide a knocker for knocking on the external wall of the powder processing container and vibrating the wall. Fig. 8 is a view showing the powder-processing container provided with a knocker on an external wall. In Fig. 8, the 'knocker' 41 is placed at the middle portion of the 'powder-processing container' 1 . Note that the number and position of the knocker is not limited , and it is possible to provide the knocker at the lower or upper portion, and to provide a plurality of knockers.

[0022]

<Processing Flow of First Embodiment

Fig. 9 is a flowchart of a fine powder generation method of the first embodiment. At the outset, in step S1 , the powder is stored in the bottom of the powder-processing container, where the internal diameter of the lower portion of the container tapers downwardly (powder storing step). Subsequently, in step S2, gas jet from the gas jet orifice toward the bottom surface of the powder-processing container is carried out (gas jet step), Subsequently, in step S3, the powder dispersed and blown upward by the gas jet is extracted from the powder-processing container (step of extracting).

[0023]

<Brief Description of Effects of First Embodiment

According to the powder dispersion apparatus of the first embodiment, it is possible to extract the powder, which has been dispersed and blown upward by the gas jet, from the outlet placed in the upper portion of the powder-processing container, thereby homogeneously dispersing the powder with high-aggregability.

[0024]

<<Second Embodiment>>

[0025]

< Configuration of Second Embodiment

Fig. 10 is a schematic view showing a configuration of a powder dispersion apparatus of a second embodiment. Similar to the first embodiment, the 'powder dispersion apparatus' 100 of the second embodiment comprises the 'powder processing container' 1 , the 'gas jet orifice' 1 1 and the Outlet' 21 . Moreover, the 'powder dispersion apparatus' 100 of the second embodiment further comprises a 'powder flow controkpole' 51 placed in the 'powder processing container' 1 , where an external diameter of the lower portion of the pole tapers downwardly, such that the powder is blown upward along an internal surface of the powder-processing container by the gas jet. [0026]

(Powder-processing container)

Fig . 1 1 is a perspective view showing a powder-processing container disassembled from the powder dispersion apparatus of Fig . 1 0. In Fig . 2 , a 'container cap' 31 provided with a 'gas inlet' 12 and the Outlet' 21 can be fit in the 'powder-processing container' 1 , and the 'powder-processing container' 1 and the 'container cap' 31 are easily assembled or disassembled . A 'gas induction tube' 1 3 connects the 'gas inlet' 12 and the 'gas jet orifice' 1 1 . The 'gas induction tube' 13 is placed inside the 'powder flow control pole' 51 . When inducting the powder into the powder-processing container, the 'powder-processing container' 1 and the 'container cap' 31 are disassembled , and the powder is ind ucted from an 'orifice' 2 of the 'powder-processing container' 1 , and after completion of induction, the 'powder-processing container' 1 is assembled with other parts.

[0027]

(Powder flow control pole)

The 'powder flow control pole' 51 is a pole where the external diameter of the lower portion of the pole tapers downwardly, such that the powder is blown upward along the internal surface of the powder-processing container by the gas jet. Fig. 12 is a view showing gas jet from the gas jet orifice to the lowest portion of the powder-processing container. As shown in Fig . 12, the external diameter of the lower portion of the 'powder flow control pole' 51 tapers downwardly, such that the powder dispersed by the gas jet moves toward the internal surface of the powder-processing container, and is blown upward along the internal surface of the powder-processing container. Thus, the space between the powder-processing container and the powder flow control pole is narrowed, so that the shearing force easily works on the powder, and uniformly dispersing the powder.

[0028]

As shown in Figs. 10 to 12, when placing the powder flow control pole in the powder processing container, the 'gas jet orifice' 1 is placed at the lowest portion of the 'powder flow control pole' 51 . This placement enables gas jet from directly above the powder stored in the lower portion of the powder processing container, thereby creating diffusion gas flow. Note that Figs. 10 to 12 show a configuration where the gas supply tube is placed inside the powder flow control pole, and the powder flow control pole can also have a function of the gas supply tube. Fig. 13 is a view showing an example of the configuration where the powder flow control pole also functions as the gas supply tube. In Fig. 13, the gas flows inside the 'powder flow control pole' 51 , and the gas inducted from the 'gas inlet' 12 flows inside the 'powder flow control pole' 51 , and is exhausted from the 'gas jet orifice' 1 1 .

[0029]

Moreover, the shape of the powder flow control pole is not limited to the above example, and the pole may have other shapes. Fig. 14 is a view showing an example where the lower portion of the powder flow control pole has an inverted approximately conical shape. In Fig. 14, the 'gas jet orifice' 1 1 is placed near the top of the approximately conical shape, and gas jet is possible from a plurality of small jet orifices. Note that the position of the gas jet orifice is not limited to the bottom portion of the powder flow control pole, and the gas jet orifice may be placed on the side surface of the lower portion of the pole. Fig . 1 5 is a view showing that a plurality of gas jet orifices is placed on the side of the lower portion of the powder flow control pole. I n Fig, 1 5 , a plurality of the 'gas jet orifices' 1 2 is placed on the side su rface of the lower portion of the 'powder flow control pole' 51 in addition to the 'gas jet orifice' 1 1 placed at the bottom of the 'powder flow control pole' 51 . The gas jet from the gas jet orifices placed on the side surface of the lower portion causes swirling flow, and the swirling flow blows the powder stored in the lower portion of the powder processing container upward . The number of the gas jet orifices placed on the side surface of the lower portion of the powder flow control pole is not limited , and it is preferable to place a plurality of orifices along the outer periphery of the powder flow control pole at regular intervals. This configuration can create the swirling flow with constant velocity in a circumferential d irection , thereby dispersing more powder aggregates.

[0030]

<Brief Description of Effects of Second Embodiment

According to the powder d ispersion apparatus of the second embod iment, it is possible to extract the powder, which has been dispersed and blown upward by the gas jet, from the outlet placed in the upper portion of the powder-processing container, thereby homogeneously dispersing the powder with high-aggregability. Moreover, according to the act of the powder flow control pole, the shearing force easily works on the powder, thereby reducing occurrences of the powder aggregates.

Description of Reference Numerals

[0031 ] 100 Powder dispersion apparatus

1 Powder processing container

2 Orifice

1 Gas jet orifice

12 Gas inlet

13 Gas induction tube

14 Other gas jet orifices

21 Outlet

31 Container cap

41 Knocker

51 Powder flow control pole

Claims

What is claimed is: 1 . A powder dispersion apparatus for inducting powder and dispersing the powder by gas jet, comprising:

a powder-processing container, where an internal diameter of a lower portion of the container tapers downwardly;

a gas jet orifice for the gas jet toward a bottom surface of the powder-processing container; and

an outlet for extracting the powder, having been dispersed and blown upward by the gas jet, from the powder-processing container.

2. The powder d ispersion apparatus according to Claim 1 , further comprising:

a powder flow control pole, where an external diameter of a lower portion of the pole tapers downwardly, such that the powder is blown upward along an internal surface of the powder-processing container by the gas jet.

3. The powder d ispersion apparatus accord ing to Claim 2 , wherein the powder flow control pole has the gas jet orifice at a lowest portion of the pole.

4. The powder dispersion apparatus accord ing to Claim 2 or

3,

wherein the powder flow control pole has the gas jet orifice on a bottom portion surface.

5. A fine powder generation method , comprising :

storing powder in a bottom portion of a powder-processing container, where an internal diameter of a lower portion of the container tapers downwardly;

jetting gas from a gas jet orifice toward a bottom surface of the powder-processing container; and

extracting the powder, having been dispersed and blown upward by the gas jet, from the powder-processing container.