Patent ID: 7833303

Claim:
Sifting apparatus, for sifting solid particles from a fluid, comprising: (a) a filter, having a filter wall with an interior surface and an exterior surface, having a principal longitudinal axis and having the shape of a surface of revolution about said axis, said filter tapering in diameter between a broader open particle collection end and a narrower open fluid inlet end, and having numerous small filter apertures extending through said filter wall 10 from said interior surface of said filter wall to said exterior surface of said filter wall; (b) a rotation means, connected to said filter, for rotating said filter in a rotation direction about said axis of said filter; (c) a fluid impeller means, connected to said filter, for causing said fluid to flow into said fluid inlet end of said filter and to flow out of said filter through said filter apertures; wherein said fluid impeller means comprises a rotating cylindrical fan blade assembly surrounding and coaxial with said filter, connected to and rotating with said filter, said fan blades being slanted in a direction opposite said rotation direction; (d) a particle collection receptacle connected to said filter at said particle collection end of said filter; and (e) baffle means, surrounding said filter and fan blade assembly, for allowing flow of said fluid through said filter only from said fluid inlet end of said filter, and wherein said particle collection receptacle is fluid tight and in fluid tight connection with said filter.