Patent ID: 8114290

Claim:
A filter device comprising a housing ( 2 ) having at least two rotation bodies ( 4 , 18 ) arranged in the housing and driven by a shaft ( 3 ), the at least two rotation bodies ( 4 , 18 ) being arranged in series in a flow direction of the housing ( 2 ), at least one guidance device ( 7 ) provided between each pair of the rotation bodies ( 4 , 18 ), the at least one guidance device connecting a pressure side ( 6 ) of an upstream one of the rotation bodies ( 4 , 18 ) to a suction side ( 5 ) of a downstream one of the rotation bodies ( 4 , 18 ) so that a pressure level in the flow direction increases from an entry of the housing ( 2 ) to an exit of the housing ( 2 ) to produce a multistage centrifugal pumping effect, and a filter arrangement ( 9 , 10 ) provided for the rotation bodies ( 4 , 18 ) or intermediate spaces between the rotation bodies ( 4 , 18 ).