Method and apparatus for separating fine particulate material from a mixture of coarse particulate material and fine particulate material

摘要

Fine particulate material is separated from a mixture of coarse particulate material and fine particulate material by passing sweep gas through the chamber of a rotating tumbler drum that contains an introduced material that is a mixture of coarse particulate material and fine particulate material. In particular, polysilicon powder may be separated from granular polysilicon. Seals are present, at locations where gas-conveying parts of the apparatus move relative to one another, to block the escape of sweep gas to the atmosphere surrounding the apparatus. A downstream seal extends between a stationary exhaust duct and an exhaust tube that rotates with the tumbler drum. The seal is protected by a flow of clean flush gas that is delivered to a gap between the exhaust duct and the exhaust tube.