Nisshin Seifun Group Inc.

Nisshin Engineering Inc.

Kazumi Kozawa

Kosuke Ando

Satoshi Akiyama

Masaru Kyugo

Daisuke Sato

Kenji Taketomi

Kenji Jikihara

Yusuke Igawa

Harutoshi Tominaga

Shunsuke Yamamoto

Toru Yoshikawa

Tatsuya Onishi

This powder-classifying apparatus has: a centrifugation chamber configured so as to be sandwiched between two opposing members; an air supply unit that supplies air into the centrifugation chamber and generates a swirl flow; a raw material supply unit that supplies raw-material powder into the swirl flow; a fine powder recovery unit having an opening part through which air that includes fine powder classified within the centrifugation chamber is ejected to outside of the centrifugation chamber; a coarse powder recovery unit provided to the outer edge part of the centrifugation chamber, for ejecting classified coarse powder to outside of the centrifugation chamber; and an annular slit provided to at least one of the members that constitute the centrifugation chamber, the slit being provided in a region between the center part of the centrifugation chamber and the outer edge part.

Powder classifying apparatus

A cyclone main body includes a cylinder-shaped upper barrel and an inverse cone-shaped lower barrel; a top plate which covers a top edge of the upper barrel and includes an opening at a center portion; a first introduction pipe which introduces a first fluid containing powder along an inner wall surface of the cyclone main body; a second introduction pipe which is disposed near the top plate in a portion upper than the first introduction pipe and introduces a second fluid; an exhaust pipe which is inserted in the opening of the top plate along a vertical center axis of the cyclone main body, makes an exhaust flow rise from the cyclone main body, and discharges the exhaust flow from the cyclone main body; and a collecting section which collects powder separated by turning movement of each of the first fluid and the second fluid in the cyclone main body.

Cyclone device and classification method

A powder classifying apparatus for classifying powder that has a granularity distribution and recovering fine powder has: a casing provided with two disc-shaped members and a surrounding wall member, a disc-shaped hollow section for classifying powder using a spinning airflow in the interior thereof being formed on the inner side of the casing; at least one powder supply opening for supplying powder into the disc-shaped hollow section; a discharge section for discharging air including fine powder discharged from the disc-shaped hollow section; a recovery unit formed in the thickness-wise center of the surrounding wall member of the casing and provided with a slit-shaped opening for recovering coarse powder discharged from the disc-shaped hollow section; and two air introduction units provided with a plurality of air introduction devices for introducing air into the disc-shaped hollow section in order to form the rotational airflow inside the disc-shaped hollow section.

A powder classifying device includes a plurality of powder classifiers that impart a whirling motion to powder with whirling gas streams to classify the powder into coarse powder and fine powder, a gas supply source that supplies the plurality of powder classifiers with gas for generating the whirling gas stream, a powder supplier that supplies the plurality of powder classifiers with powder having a particle size distribution, a fine powder collecting section that collects fine powder classified by each of the plurality of powder classifiers, a coarse powder recovery section that recovers coarse powder classified by each of the plurality of powder classifiers, and a controller that controls flow rates of gases supplied to the plurality of powder classifiers so that a classification point is substantially equal among the plurality of powder classifiers.

Powder classifying device

A method of grinding a powder, which grinds a powder using an air stream generated inside a grinding chamber in a jet mill in which there is no place to retain powder inside the grinding chamber is provided. The method includes: a mixing step of mixing an auxiliary agent with the powder; a heating step of heating a high pressure gas; a supplying step of supplying the high pressure gas heated in the heating step into the grinding chamber; an injecting step of injecting the powder in which the auxiliary agent is mixed in the mixing step into the grinding chamber in a predetermined amount in which the concentration of the auxiliary agent inside the grinding chamber is lower than an ignition concentration; and a grinding step of grinding the powder using the air stream generated inside the grinding chamber by the high pressure gas supplied in the supplying step.

Method of grinding powder

A powder-classification method includes a mixing step in which a powder and a liquid additive are mixed together, a drying step in which the powder mixed in the mixing step is dried, a loading step in which the powder dried in the drying step is loaded into a fluid classifier, a heating step in which a gas is heated, a supplying step in which the gas heated in the heating step is supplied to the fluid classifier, and a classifying step in which the powder is classified in the fluid classifier based on a grain size of the powder.

Powder-classification method

Provided is a method for classifying a powder using a classifier, wherein the method comprises: a mixing step for mixing a powder and an auxiliary agent formed from an alcohol aqueous solution containing 10 to 50 mass % of an alcohol; an introduction step for introducing the powder mixed in the mixing step to the classifier; a heating step for heating a gas; a feed step for feeding the gas heated in the heating step to the classifier; and a classifying step for classifying the powder in the classifier on the basis of grain size.

Method for classifying powder

A method for classifying a powder using a fluid classifier, which comprises a mixing step of mixing a powder and an assistant agent composed of an alcohol, an input step of inputting the powder mixed in the mixing step into the fluid classifier, a heating step of heating a gas, a supply step of supplying the gas heated in the heating step into the fluid classifier, and a classification step of classifying the powder according to particle diameters in the fluid classifier.

A method for manufacturing a powder includes a mixing step in which a powder and a liquid additive are mixed together, a drying step in which the powder mixed in the mixing step is dried, a loading step in which the powder dried in the drying step is loaded into a pulverizer, a heating step in which a high-pressure gas is heated, a supplying step in which the high-pressure gas heated in the heating step is supplied to the pulverizer, and a pulverizing step in which the powder is pulverized by the pulverizer.

Method for manufacturing powder

The powder classifying device classifies powder having a particle size distribution and collects the classified powder. The device includes a disc-like cavity to which the powder is supplied and where the supplied powder is classified, a powder supply port for supplying the powder to the cavity, guide vanes arranged so as to extend from an outer periphery of the cavity in an inner direction at a predetermined angle, a discharge unit for air streams including fine particles discharged from the cavity, a collection unit for coarse particles discharged from the cavity and air nozzles arranged below the guide vanes on an outer peripheral wall of the cavity along a tangential direction of the outer peripheral wall and blow compressed air into an inside of the cavity.

A jet mill has a disk-shaped hollow part in the interior of the mill body. The hollow part is divided into an annular grinding zone for grinding a material by high-speed swirling air flows supplied through plural air nozzles and an annular classifying zone provided inside the grinding zone and communicated to an exit space for classifying the ground material by the swirling air flows in the grinding zone. An annular first constricted passageway is arranged between the grinding zone and the classifying zone to thereby divide and communicate them, and preferably an annular second constricted passageway between the classifying zone and the inside exit thereof. Accordingly, a jet mill realizing a high classification precision for a desired particle size of ground material with a narrow size distribution and having a simple inner configuration to allow easy cleaning before and after operation can be provided.

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Fujimino, Japan

Kazumi Kozawa