Filter for removing particles and aerosols from air and other gases

Claim 1

A centrifugal-type filter comprising: a casing having a front upstream wall portion of generally uniform cross-sectional area along its axial length and a rear downstream wall portion contiguous to said front portion and also of generally uniform cross-sectional area along its axial length greater than the cross-sectional area of said front portion, said front portion being spaced from and encompassing a rotatable filter assembly axially aligned and supported within said casing, said filter assembly including a hollow cylindrical body of foraminous filter material and a perforated tube contacting and forming a receptacle for said hollow cylindrical body, said perforated tube being closed at one end adjacent to said rear wall portion, means for rotating said receptacle so that gases entering the open end of said tube containing said foraminous filter material pass through the hollow cylindrical foraminous filter and the tube sidewall, said front wall portion of said casing and said filter assembly defining a first area therebetween which extends the length of said filter assembly, said front wall portion of said casing further including cover means covering the front end of the casing extending radially inwardly toward the axis of said casing and having an orifice therein defining an inlet positioned adjacent to and communicating with the open end of the filter assembly through which gases pass into the interior of said filter assembly; said rear wall portion of said casing extending axially beyond said filter assembly to form a downstream second area, said casing further including an outwardly flanged transitional wall portion and increasing cross-sectional between said front and rear wall portions of said casing and extending abruptly outwardly in a radial direction beyond the radial extremity of said front wall portion of said casing whereby said rear wall portion forms a bulbous end of said casing which causes a pressure drop in the gases passing through said casing, permits easier removal of residual pollutants and enhances gas flow through the filter assembly, said rear wall portion being further defined in that it terminates in an open end which forms an outlet for gases passing through said casing and further includes a discharge outlet in the rear wall portion for liquids separated from said gases.