Patent ID: 7395935
Filing Date: 2008-07-08
Classification: B01D,B23Q

Abstract:
1. A filter device comprising: a filter tank stored with a contaminated fluid which contains chips; a filter drum rotatably disposed in the filter tank and immersed in the contaminated fluid; and a drive mechanism which rotates the filter drum around an axis of the filter drum, the filter drum including a filter element which is produced by forming a porous plate having a large number of circulation holes therein into a cylindrical shape, such that an inlet port of each said circulation hole opens in an outer peripheral surface of the porous plate and that an outlet port opens in an inner peripheral surface of the porous plate, the circulation holes of the porous plate being formed by etching and having a shape such that a smallest opening is formed in a cross section of the porous plate in a thickness direction thereof so that an opening width thereof is minimum between the inlet port and an intermediate part with respect to the plate thickness direction, that the opening width gradually increases from the smallest opening toward the outlet port, and that the opening width is maximum at the outlet port; an exit section situated in a position higher than a fluid surface of the contaminated fluid in the filter tank and a scraper conveyor for scraping out chips settled on a bottom portion of the filter tank toward the exit section, said scraper conveyor including a lower portion which moves along the bottom portion of the filter tank toward the exit section and an upper portion which passes over the lower portion and returns to a starting end of the lower portion; said filter drum being arranged horizontally between the lower portion and the upper portion of the scraper conveyor.