JP2010260034A - High-precision classifier for shirasu balloon and high-precision classification method with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a Shirasu balloon high-precision classifier that highly precisely classifies Shirasu balloons of various particle diameters into respective ranges of predetermined particle diameters and to provide a high-precision classification method with the same. <P>SOLUTION: The high-precision classifier 1 is provided with a vessel 2 which conveys a powdery Shirasu balloons 10 into a powder convey gas pipe 8, a pressurizer 4 which sends a pressurizing gas, housings 3 which contain their respective filters 6 in their insides and feed the Shirasu balloons 10 into their respective first gas pipes 15 communicating with their respective insides of the filters 6 and into their respective second gas pipes 16 communicating with the outsides of their respective filters 6, first pressure regulation valves 13 which regulate the pressures in the first gas pipes 15, and second pressure regulation valves 14 which regulate the pressures in the second gas pipes 16, wherein the first pressure regulation valves 13 and the second pressure regulation valves 14 are respectively regulated to produce a differential pressure between the insides and outsides of the filters 6 to classify the Shirasu balloons 10. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a precision classification device for shirasu balloons and a precision classification method therefor, and in particular, a precision classification device for shirasu balloons for classifying powdered shirasu balloons having various particle diameters for each predetermined particle diameter. , And its precision classification method.

  “Shirasu” is a general term for white volcanic eruptions widely distributed in southern Kyushu and secondary sediments derived from them, and they form a vast plateau around Kagoshima Bay. This shirasu is called vitreous volcanic debris because it is rich in glass.

  It was found that when this shirasu was heated at a high temperature in an electric furnace and fired and foamed, hollow glass spheres (balloons) of 30 to 600 μm were formed. This hollow glass sphere is generally called a shirasu balloon. This is because shirasu has water and volatile components therein, and when heated rapidly within the softening temperature, they are gasified, foamed and expanded to form a hollow body.

  This Shirasu balloon has many features such as light weight, heat insulation, fire resistance, and the like, and thus is widely used in the fields of building materials, fireproof heat insulation materials, soil conditioners, and the like. Among these uses, this shirasu balloon has been found to be effective in removing the stratum corneum of the skin or removing oils and fats on the surface of the skin. For example, cosmetic additives, dispersants, facial soaps and shampoos, etc. It is used as an additive. In this application, a shirasu balloon having a particle size in the range of about 70 μm to about 5 μm is used.

  In this application, a shirasu balloon having a particle size in the range of about 70 μm to about 5 μm is used. The Shirasu balloon may be required to have an appropriate particle size range for each application. For example, ultrafine particles of about 5 μm are used for cosmetic additives, a particle size range of 50 μm to 70 μm is used as a dispersant, and a uniform particle size of 70 μm is used as an additive such as facial soap and shampoo. Adopted. Therefore, it is necessary to classify the powdered shirasu balloon mixed with various particle diameters for each desired particle diameter range. At present, this shirasu balloon is generally classified by a centrifuge.

  On the other hand, Patent Document 1 discloses a powder classification apparatus and method. Here, there is described a wet classifier that maintains a laminar flow by suppressing a turbulent flow in the laminar flow by disposing a laminar flow clearing device and a classification adjusting plate inside the laminar flow tube. And the powder particles flowing in the laminar flow tube have different drop speeds due to the difference in particle size, resulting in a difference in the horizontal reach distance, so that the particles with uniform particle size are captured in order at the take-out ports provided at regular intervals. .

JP-A-9-206627

  At present, it is common to classify shirasu balloons using a centrifuge, but there is a problem that precise classification cannot be performed because there is not much difference in specific gravity due to the difference in particle size.

  On the other hand, Shirasu balloons are used, for example, as cosmetic additives, dispersants, or additives such as facial soaps and shampoos, but the range of particle sizes used for each application differs, and precise classification is required. Is done. Furthermore, there is an increasing demand for more stable classification of the particle size of the shirasu balloon to stabilize the product quality.

  On the other hand, there is a method of classifying by applying a shirasu balloon to a filter, but there is a problem that the shirasu balloon that is fine particles is electrostatically adsorbed to the filter mesh by static electricity on the filter surface and cannot be classified precisely.

  An object of the present application is to solve the above problems and to provide a precision classification device for a shirasu balloon and a precise classification method for precisely classifying a powder shirasu balloon with various particle diameters in a predetermined particle diameter range. Is to provide.

  In order to achieve the above object, the Shirasu balloon precision classification apparatus according to the present invention classifies a Shirasu balloon precision classification apparatus that classifies powder Shirasu balloons having various particle diameters within a predetermined range of particle diameters. In, the powder storage container for storing the shirasu balloon and transported to the transport pipe, the pressurizer for supplying the pressurized gas into the powder storage container, and the filter built in, and transported from the transport pipe A powder classifier for classifying a shirasu balloon, a first pipe for communicating the shirasu balloon that has passed through the filter to the first powder container, and a powder classifier. A second pipe for communicating a shirasu balloon that does not pass through the filter to the second powder container, a first pressure regulating valve that regulates the pressure in the first pipe, 2 Adjust the pressure in the pipe A second pressure regulating valve that generates a differential pressure between the inside and the outside of the filter by the first pressure regulating valve and the second pressure regulating valve, so that the shirasu balloon is in a predetermined particle size range. It is characterized by classification.

  With the above configuration, the Shirasu balloon precision classifier adjusts the pressure outside the filter inside the powder classifier and the pressure inside the filter to generate a differential pressure, and electrostatically removes the Shirasu balloon within the particle size range that passes through the filter. It can be passed by overcoming the electrostatic adsorption due to the. That is, a first pressure adjustment valve provided in a first pipe that conveys a shirasu balloon that has passed through the filter, and a second pressure adjustment valve provided in a second pipe that carries the shirasu balloon that does not pass through the filter. By adjusting the pressure, a differential pressure is generated between the pressure outside the filter and the pressure inside the filter, and this differential pressure can facilitate the passage of a shirasu balloon having a particle size range that should pass through the filter.

  The precision classifier for the Shirasu balloon includes n powder classifiers, each of which has a first pipe and a second pipe, and is connected in series via the first pipe. It is preferable that filters having different mesh widths are respectively built in, and the shirasu balloon is classified into a particle size range of n + 1 by the first pressure regulating valve and the second pressure regulating valve. Thereby, the range of a finer particle size can be set. Also, the equipment can be configured corresponding to the number of particle size ranges of the shirasu balloons to be classified.

  In addition, in the Shirasu balloon precision classification device, it is preferable that the powder storage container stirs the stored Shirasu balloon with a siphon tube and transports it to the transport pipe. Thereby, the shirasu balloon which is powder can be stirred in the powder container by the cyfin tube, and can be easily transported to the transport pipe.

  Further, in the Shirasu balloon precision classifying device, the first pipe and the second pipe are preferably gas pipes having the same diameter. Thereby, the 1st piping and the 2nd piping become the same cross-sectional area, and can make the pressure adjustment by a 1st pressure regulating valve and a 2nd pressure regulating valve easy.

  In order to achieve the above object, the Shirasu balloon precision classification method according to the present invention is a Shirasu balloon precision classification method of classifying a powder Shirasu balloon in which various particle sizes are mixed into a predetermined particle size range. A step of storing the shirasu balloon in a powder container, supplying a pressurized gas into the powder container, and transporting the shirasu balloon to a powder classifier incorporating a filter, and powder classification A second pipe in which a shirasu balloon that communicates with the inside of the filter of the container and that passes through the filter is conveyed in the first pipe, and communicates with the outside of the filter of the powder classifier and that does not pass through the filter. And adjusting the pressure in the pipes to classify the shirasu balloon, respectively, and filtering by the respective pressure regulating valves of the first pipe and the second pipe To generate pressure difference inside and outside, characterized in that classification by range silas balloons having a predetermined particle size.

  With the above configuration, the Shirasu balloon precision classification method adjusts the pressure inside the filter inside the classifier and the pressure inside the filter to generate a differential pressure, and allows the Shirasu balloon within the range of the particle size passing through the filter to pass more. Can be made easier. That is, by adjusting the pressure control valves provided in the pipe for supplying the shirasu balloon in the range of the particle size that has passed through the filter and the pipe for supplying the shirasu balloon in the range of the particle size that does not pass through the filter, A differential pressure is generated between the pressure and the pressure inside the filter.

  In addition, the precision classification method of the Shirasu balloon is such that n powder classifiers each having a built-in filter having a different mesh width are connected in series via the first pipe, with the first pipe and the second pipe communicating with each other. The shirasu balloon is preferably classified into a particle size range of n + 1 by a first pressure regulating valve and a second pressure regulating valve provided in each powder classifier. Thereby, the range of a finer particle size can be set. Also, the equipment can be configured corresponding to the number of particle size ranges of the shirasu balloons to be classified.

  Moreover, as for the precise classification method of the shirasu balloon, it is preferable that the shirasu balloon accommodated in the powder container is agitated by the siphon tube and conveyed to the conveying pipe. Thereby, the shirasu balloon which is powder can be stirred in the powder container by the cyfin tube, and can be easily transported to the transport pipe.

  Furthermore, in the precision classification method of the shirasu balloon, it is preferable that the first pipe and the second pipe are gas pipes having the same diameter. Thereby, the 1st piping and the 2nd piping become the same cross-sectional area, and can make the pressure adjustment by a 1st pressure regulating valve and a 2nd pressure regulating valve easy.

  As described above, according to the shirasu balloon precision classification apparatus according to the present invention, the shirasu balloon precision classification that precisely classifies the powder shirasu balloons having various particle diameters for each predetermined particle diameter range. An apparatus and a precision classification method thereof can be provided.

It is explanatory drawing which shows schematic structure of 1st Embodiment about the precision classification apparatus of the shirasu balloon based on this invention. It is explanatory drawing which shows the means which generate | occur | produces the differential pressure | voltage between the filter inside in a housing, and the exterior. It is a flowchart which shows the precision classification method of a shirasu balloon.

  Hereinafter, embodiments of a precision classification device for a shirasu balloon according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of one embodiment of a precision classification device for a shirasu balloon according to the present invention.

(Components of Shirasu Balloon Precision Classification Device)
A precision classification device 1 for a shirasu balloon includes a vessel 2 that is a powder container, a housing 3 that is a powder classifier, a pressurizer 4, a first gas pipe 15 that is a first pipe, and a second pipe that is a second pipe. 2 gas pipe 16, first pressure regulating valve 13, and second pressure regulating valve 14. In the present embodiment, the precision classification device 1 that classifies the shirasu balloon 10 into three particle diameter ranges using two housings 3 will be described. However, the present invention is not limited to this, and the housing 3 includes, for example, one unit, It may be three.

  The precision classifier 1 is arranged in order of the pressurizer 4, the vessel 2, the housing 3a, and the housing 3b from the upstream side, and the housing 3a and the housing 3b are connected in series via the first gas pipe 15a. Also, the first powder 12a is connected to the first receiver 12a, which is a first powder container, from the housing 3a through the second gas pipe 16a, and the second powder container is connected from the housing 3b, via the second gas pipe 16b. Connected to the receiver 12a '. And it connects to the 2nd receiver 12b via the 1st gas pipe 15b from the housing 3b. The first gas pipes 15a and 15b and the second gas pipe 16a are provided with a pair of pressure regulating valves 13 and 14 and a pressure gauge 11. Furthermore, the first gas pipes 15a and 15b and the second gas pipes 16a and 16b are appropriately provided with clamps 7 for connecting the pipes to each other.

  Further, a gas supply gas pipe 17 is disposed from the pressurizer 4 to the vessel 2, and a powder carrier gas pipe 8 is disposed from the vessel 2 to the housing 3a. A pair of pressure valves 5 and a pressure gauge 11 are provided on the upstream side and the downstream side of the vessel 2. Further, the gas supply gas pipe 17 and the powder carrier gas pipe 8 are appropriately provided with clamps 7 for connecting the pipes.

(Function of each component)
The pressurizer 4 supplies pressurized gas into the vessel 2 through the gas supply gas pipe 17. The pressure of this gas is measured by the pressure gauge 11 and adjusted by the pressure valve 5. The gas supply gas pipe 17 is inserted into the vessel 2 as a siphon pipe 9. The vessel 2 is a cylindrical container in which a powdered shirasu balloon 10 in which various particle sizes are mixed is accommodated by batch processing. The shirasu balloon 10 accommodated by the pressurized gas discharged from the siphon tube 9 is agitated and conveyed to the powder carrier gas tube 8 provided in the vessel 2. The pressure of the gas containing the shirasu balloon 10 conveyed from the vessel 2 is measured by the pressure gauge 11 and adjusted by the pressure valve 5.

  The housing 3a incorporates a cylindrical filter 6a, and the inside and outside of the filter 6a are defined. The gas including the shirasu balloon 10 transferred from the powder transfer gas pipe 8 enters the housing 3a. The first gas pipe 15a connected to the housing 3a communicates with the inside of the filter 6a in the housing 3a, and conveys the shirasu balloon 10 that has passed through the filter 6a to the housing 3b. The second gas pipe 16a connected to the housing 3a communicates with the outside of the filter 6a in the housing 3a, and conveys the shirasu balloon 10 that does not pass through the filter 6a to the first receiver 12a. The first pressure adjustment valve 13a adjusts the pressure in the first gas pipe 15a, and the second pressure adjustment valve 14a adjusts the pressure in the second gas pipe 16a.

  In this embodiment, the range of the particle size of the shirasu balloon 10 that is accommodated and classified in the vessel 2 is in the range of approximately 70 μm to approximately 5 μm. The filter 6a in the housing 3a is covered with a mesh width of about 50 μm. Accordingly, the shirasu balloon 10 having a particle size of less than about 50 μm among the shirasu balloons 10 having various particle sizes mixed therein is connected to the housing 3b through the first gas pipe 15a communicating with the inside of the filter 6a together with the gas. Conveyed in. Further, the shirasu balloon 10 having a particle size exceeding about 50 μm is conveyed to the first receiver 12a via the second gas pipe 16a communicating with the outside of the filter 6a together with the gas. In this manner, the first receiver 12a accommodates the shirasu balloon 10 having a size of about 50 μm to about 70 μm, and is mainly used as a dispersant.

  The filter 6b in the housing 3b is covered with a mesh width of about 5 μm. Accordingly, the shirasu balloon 10 having a particle diameter of less than about 5 μm among the shirasu balloons 10 is conveyed to the second receiver 12b through the first gas pipe 15b communicating with the inside of the filter 6b together with the gas. In this way, the second receiver 12b accommodates the shirasu balloon 10 which is an ultrafine particle of approximately 5 μm and is used for cosmetic additives and the like. Further, the shirasu balloon 10 having a particle size of less than about 50 μm and over about 5 μm is conveyed to the first receiver 12a ′ via the second gas pipe 16a communicating with the outside of the filter 6a together with the gas. In this manner, the first receiver 12a ′ accommodates the shirasu balloon 10 of about 10 μm to about 45 μm, and is used for an application suitable for this particle size range.

  In the classification of the Shirasu balloon 10 described above, the Shirasu balloon 10 as particles is electrostatically attracted to the meshes of the filters 6a and 6b due to static electricity on the surfaces of the filters 6a and 6b. Therefore, this can be achieved by using means for generating a differential pressure between the inside and outside of the filters 6a and 6b in the housings 3a and 3b, which will be described later.

FIG. 2 shows a means for generating a differential pressure between the inside and outside of the filter 6 in the housing 3. The pressure at the inlet of the gas housing 3 including the shirasu balloon 10 transferred from the powder transfer gas pipe 8 is assumed to be “P”. Further, the pressure of the gas in the first gas pipe 15a which connects to the housing 3a and p _1, the pressure of the gas in the second gas pipe 16a which connects to the housing 3a and p _2. Here, both the first gas pipe 15a and the second gas pipe 16a are gas pipes having a diameter of about 20 mm and the same diameter. Furthermore, the powder carrier gas pipe 8 is also a gas pipe having a diameter of about 20 mm. Therefore, from the principle of hydrodynamics, the flow rate of the gas input to the housing 3a is equal to the sum of the output first gas pipe 15a and second gas pipe 16a. That is, the pressure (p ₁ ) and the pressure (p ₂ ) in the first gas pipe 15a and the second gas pipe 16a to be outputted are P / P with respect to the pressure (P) in the powder carrier gas pipe 8, respectively. 2. That is, in the case of the fully opened first pressure regulating valve 13a and the second pressure regulating valve 14a are both theoretically, of the gas in the first gas pipe 15a pressure (p ₁₎ and in the second gas pipe 16a The gas pressure (p ₂ ) is both P / 2, and no differential pressure is generated between the inside and the outside of the filter 6a.

Ｐ）により、フィルタ６ａを通過する粒径の範囲のシラスバルーン１０を静電気による静電吸着に打ち勝たせて通過させることができる。Here, if only the second pressure regulating valve 14a is throttled, the flow rate of the gas in the second gas pipe 16a decreases, and the flow rate of the gas in the first gas pipe 15a increases. That is, the gas pressure (p ₂ ) in the second gas pipe 16a increases, and the gas pressure (p ₁ ) in the first gas pipe 15a decreases. The gas pressure in the second gas pipe 16a _{(p 2)} and the pressure of the gas in the first gas pipe 15a _{(p 1)} and the

By P), the shirasu balloon 10 having a particle diameter range that passes through the filter 6a can be passed over the electrostatic adsorption due to static electricity.

の粒径が略５０μｍを境界にして分級することができる。また、ハウジング３ｂの第１圧力調整弁１３ｂ及び第２圧力調整弁１４ｂにより、フィルタ６ｂの内部と外部とに差圧（

級することができる。Thus, the first pressure regulating valve 13a and the second pressure regulating valve 14a of the housing 3a

Can be classified with a particle size of about 50 μm as a boundary. Further, the first pressure regulating valve 13b and the second pressure regulating valve 14b of the housing 3b are used to generate a differential pressure (inside and outside the filter 6b).

Can be classified.

(Precision classification method of Shirasu balloon)
FIG. 3 shows a flowchart of the precision classification method of the shirasu balloon 10. The precision classification method of the shirasu balloon 10 is performed by the following steps with reference to FIG. First, the shirasu balloon 10 is stored in the vessel 2 (S1). Next, pressurized gas is supplied into the vessel 2, and the shirasu balloon 10 is conveyed to the housing 3a in which the filter 6a is built (S2). Then, the pressure in the first gas pipe 15a that communicates with the inside of the filter 6a of the housing 3a and the shirasu balloon 10 that has passed through the filter 6a and the outside of the filter 6a of the housing 3a and that does not pass through the filter 6a. The pressure in the second gas pipe 16a through which the balloon 10 is conveyed is adjusted (S3). The shirasu balloon 10 conveyed by the second gas pipe 16a is accommodated in the first receiver 12a and classified (S4). Here, it is determined whether the classification of the shirasu balloon 10 has been completed (S5). When the classification of the shirasu balloon 10 is completed, the shirasu balloon 10 conveyed by the first gas pipe 15a is accommodated in the second receiver 12b, and the classification is completed (S6).

  When the shirasu balloon 10 is further classified, the shirasu balloon 10 conveyed by the first gas pipe 15a is conveyed to the housing 3b (S6). Then, the process returns to S3, communicates with the inside of the filter 6b of the housing 3b, communicates with the pressure in the first gas pipe 15b in which the shirasu balloon 10 that has passed through the filter 6b is conveyed, and communicates with the outside of the filter 6b of the housing 3b. The pressure in the second gas pipe 16b through which the shirasu balloon 10 that does not pass through is conveyed is adjusted (S3). The shirasu balloon 10 conveyed by the second gas pipe 16b is accommodated in the first receiver 12a 'and classified (S7). Further, the shirasu balloon 10 conveyed by the first gas pipe 15b is accommodated in the second receiver 12b, and the classification is completed (S6). In this way, the shirasu balloon 10 is classified by generating a differential pressure between the inside and the outside of the filter 6a by the first pressure regulating valve 13a of the first gas pipe 15a and the second pressure regulating valve 14a of the second gas pipe 16a. To do.

  These steps are repeated according to the quantity of the housing 3. That is, the first gas pipe 15 and the second gas pipe 16 communicate with each other, and the n housings 3 each containing the filter 6 having a different mesh width are connected in series via the first gas pipe 15. The balloon 10 is classified into a particle size range of n + 1 by the first pressure regulating valve 13 and the second pressure regulating valve 14 provided in each housing 3. In the present embodiment, the housing 3a is a filter 6a having a mesh width of about 50 mμ, and the housing 3b is a filter 6b having a mesh width of about 5 mμ. By these two filters 6a and 6b, the shirasu balloon 10 is classified into three particle diameter ranges.

  Thus, in the precision classification method of the present Shirasu balloon, the pressure difference between the inside and the outside of the filter 6a is controlled by the first pressure adjusting valve 13a of the first gas pipe 15a and the second pressure adjusting valve 14a of the second gas pipe 16a. To classify the shirasu balloon 10.

  Further, in the precision classification method of the present Shirasu balloon, the Shirasu balloon 10 accommodated in the vessel 2 is agitated by the siphon tube 9 and conveyed to the powder carrier gas tube 8. Thereby, the shirasu balloon 10 which is powder can be stirred in the vessel 2 by the cyfin tube 9 and can be easily transported to the powder transport gas tube 8.

  Furthermore, in the precision classification method of the present Shirasu balloon, the first gas pipes 15a and 15b and the second gas pipes 16a and 16b are gas pipes having the same diameter. Thereby, the first gas pipes 15a and 15b and the second gas pipes 16a and 16b have the same cross-sectional area, and pressure adjustment by the first pressure adjustment valves 14a and 14b and the second pressure adjustment valves 15a and 15b is performed. Can be easily.

  1 precision classification device (for Shirasu balloon), 2 vessel (powder container), 3a, 3b housing (powder classifier), 4 pressurizer, 5 pressure valve, 6a, 6b filter, 7 clamp, 8 powder transfer Gas pipe, 9 Siphon pipe, 10 Shirasu balloon, 11 Pressure gauge, 12a, 12a ′ First receiver (first powder container), 12b Second receiver (second powder container), 13a, 13b 1 pressure regulating valve, 14a, 14b second pressure regulating valve, 15a, 15b first gas pipe, 16a, 16b second gas pipe, 17 gas supply gas pipe.

Claims (8)

In a precision classification device for shirasu balloons that classifies powdered shirasu balloons with various particle sizes mixed for each predetermined particle size range,
A powder storage container for storing a shirasu balloon and transporting it to a transport pipe;
A pressurizer for supplying pressurized gas into the powder container;
A powder classifier that has a built-in filter and classifies shirasu balloons transported from the transport pipe,
A first pipe that communicates with the inside of the filter in the powder classifier and conveys the shirasu balloon that has passed through the filter to the first powder container;
A second pipe that communicates with the outside of the filter in the powder classifier and conveys the shirasu balloon that does not pass through the filter to the second powder container;
A first pressure regulating valve for regulating the pressure in the first pipe;
A second pressure regulating valve that regulates the pressure in the second pipe,
A precision of a shirasu balloon characterized in that a differential pressure is generated between the inside and the outside of the filter by the first pressure regulating valve and the second pressure regulating valve, and the shirasu balloon is classified according to a predetermined particle size range. Classification device.   The precision classification apparatus for a shirasu balloon according to claim 1, wherein each of the first and second pipes communicates with each other and n powder classifiers are connected in series via the first pipe. Each powder classifier has a built-in filter with a different mesh width, and the shirasu balloon is classified into a particle size range of n + 1 by the first pressure regulating valve and the second pressure regulating valve. Shirasu balloon precision classifier.   The precision classification apparatus for a shirasu balloon according to claim 1 or 2, wherein the powder storage container agitates the shirasu balloon stored in the siphon tube and conveys it to the conveyance pipe. Classification device.   The precision classification apparatus for a shirasu balloon according to any one of claims 1 to 3, wherein the first pipe and the second pipe are gas pipes having the same diameter, respectively. Precision classifier. In a precision classification method of a shirasu balloon that classifies a powder shirasu balloon in which various particle sizes are mixed for each predetermined particle size range,
Storing the shirasu balloon in a powder container;
Supplying pressurized gas into the powder container and transporting the shirasu balloon to a powder classifier incorporating a filter;
A pressure in the first pipe that communicates with the inside of the filter of the powder classifier and the shirasu balloon that has passed through the filter, and a shirasu balloon that communicates with the outside of the filter of the powder classifier and that does not pass through the filter are conveyed. And adjusting the pressure in each of the two pipes to classify the shirasu balloon,
A shirasu balloon characterized in that the shirasu balloon is classified according to a predetermined particle size range by generating a differential pressure between the inside and outside of the filter by the respective pressure regulating valves of the first pipe and the second pipe. Precision classification method.   6. The precision classification method for a shirasu balloon according to claim 5, wherein the first and second pipes communicate with each other and n powder classifiers each having a built-in filter having a different mesh width are provided. The Shirasu balloon is classified into a particle size range of n + 1 by a first pressure regulating valve and a second pressure regulating valve respectively provided in each powder classifier. A precise classification method for Shirasu balloons.   The shirasu balloon precision classification method according to claim 5 or 6, wherein the shirasu balloon stored in the powder container is agitated by a siphon tube and transported to a transport pipe. Precision classification method.   The precision classification method for a shirasu balloon according to any one of claims 5 to 7, wherein the first pipe and the second pipe are gas pipes having the same diameter, respectively. Precision classification method.

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