Process air automatic self-cleaning air filtration system

Claim 1

A gas filtration system comprising a frame having an upstream side and a downstream side supporting a filter bank transversely in a gas stream to remove particulate solids therefrom said filter bank comprising a plurality of vertically disposed horizontal rows of mechanical filter elements disposed at an acute angle to the directon of flow of the gas, means for washing said particulate solids from said filter elements including isolator means comprising an upstream panel dimensioned to isolate a row of said filter elements in said bank from passage of gas therethrough and adapted to form a substantial gas and liquid tight seal with the upstream side of said frame and spray means housed in a downstream panel which panel is adapted to form an essentially gas and liquid tight seal with the downstream side of said frame said upstream and downstream panels including seals in contact with said frame said spray means includNg a header pipe extending horizontally across each said isolated row of filter elements and having a plurality of horizontally spaced nozzles therein said pipe being rotatable on a longitudinal axis between two positions such that a washing liquid spray may be directed at different heights on the downstream side of each said isolated row of filter elements, means for rotating said pipe between said two positions comprising a linkage connected adjacent one end thereof to said header pipe and adjacent the other end thereof eccentrically on a plate member arranged to be driven by a drive means, means for linearly moving said wash means vertically and sequentially to each row of filter elements in said bank, comprising a first chain attached at one end thereof to the bottom of the downstream panel and at the other end thereof adjacent the top of the upstream panel, said chain passing around a driven sprocket adjacent the base of the frame and around a first pair of horizontally spaced idler sprockets adjacent the top of the frame and a second chain attached at one end adjacent the bottom of said upstream panel and at the other end adjacent the top of said downstream panel, said second chain passing around an idler sprocket adjacent the base of said frame and around a second pair of horizontally spaced idler sprockets adjacent the top of said frame, means for maintaining said seals between said panels and said frame during washing of each row of filter elements, comprising spring loaded roller means mounted on each panel and arranged to roll along a vertically extending strip during vertical movement of said washing means and to contact cam means of said strip opposite each row of filter elements whereby to increase the pressure of each of said panels on said frame and means for collecting the washing liquid from the upstream side of each isolated row of filters including tray means located below and on the upstream side of each of said rows of filter elements adapted to pass liquid collected therein via a plenum and a discharge duct in said frame, to a drain tank to cause said liquid to be discharged from said system without contacting portions of said system through which gas may pass whereby said filter bank may be cleaned during operation of said system.