Patent ID: 6547844
Filing Date: 2003-04-15
Classification: B01D,C23C,Y02C,Y10S

Abstract:
A trap device arranged on an exhaust path of an airtight vessel evacuated by a vacuum pump, for removing solidified gas as solid in this exhaust path;wherein said trap device comprises a vessel having in its interior a gas flow path connected to said exhaust path, said flow path comprises a plurality of annular first flow paths and second flow paths connected between said first flow paths, and the flow path cross-sectional area of said first flow paths is changed at certain positions, said first flow path is formed by a plurality of thin plates connected to the surface of a shaft element arranged in the interior of said vessel; wherein said second flow path is formed by apertures formed in certain positions of said thin plates; and wherein the flow path cross-sectional area of said first flow paths is changed by forming a step at a certain position of said thin plates; and wherein the flow velocity of gas in said flow path is controlled to a certain flow velocity in accordance with position on this flow path.