Dust filter

Claim 1

A dust filter to be mounted on the upper end of an air exhaust pipe comprising, in combination, a circular wall defining an impervious tubular housing having an open bottom inlet for the axial reception of exhaust air and means for attaching it to the upper end of an exhaust pipe; said housing having a closed top and diametrically opposed lateral exhaust outlets formed in the side thereof adjacent to the top; said outlets being of substantial width and extending downwardly more than half of the height of said housing; a tubular filter unit mounted in said housing and covering said lateral exhaust outlets so as to filter dust particles from the air being exhausted therethrough; a power driven shaft rotatably mounted in the top of said housing and depending concentrically therefrom; a pair of brushes vertically coextensive with said filter unit mounted on said shaft for rotation therewith and engaging the inner surface of said filter to brush therefrom dust particles which are deposited by air passing vertically through said open bottom inlet and laterally out of said exhaust outlets; filtered dust particle collecting means concentric and radially coextensive with said filter comprising an annular trough fixed to the inside bottom portion of said circular wall of said housing and encircling said air inlet; a dust outlet pipe connected to said trough and a dust particle scraper fixed to said shaft and conforming with and movable in said trough to move collected dust particles to said dust outlet pipe; and a hood fixed to and projecting outwardly of said housing over each of said entire exhaust outlets to exclude rain from within said housing.