Process and apparatus for separating particulate matter from gaseous media

Claim 1

In a process for separating particulate matter from a contaminated gaseous medium containing said particulate matter therein, comprising: (A) passing said contaminated gaseous medium through a first swirl-inducing zone to form a swirling contaminated gaseous medium, (B) introducing said swirling contaminated gaseous medium into a cyclonic separation zone via a path adjacent an inner surface of a wall defining a periphery of said separation zone to separate at least a portion of said particulate matter from said swirling contaminated gaseous medium and form a gaseous product which is at least partially depleted in said particulate matter, and (C) removing said gaseous product from said separation zone through a gaseous exhaust flow zone disposed radially inwardly of said first swirl-inducing zone, the improvement for increasing separation efficiency, which comprises: (D) passing a substantially contaminant-free gaseous medium through a second swirl-inducing zone to form a co-swirling substantially contaminant-free gaseous medium, (E) introducing said co-swirling gaseous medium into said separation zone through an introduction zone disposed radially inwardly of said swirling contaminated gaseous medium and radially outwardly of said exhaust flow zone, and (F) employing an additional wall to separate said introduction zone from the so-introduced swirling contaminated gaseous medium, said additional wall extending into said separation zone, said exhaust flow zone extending into said separation zone further than said additional wall so extends, such that separation of the introduced co-swirling contaminated gaseous medium from the introduced swirling substantially contaminant-free gaseous medium is terminated before the swirling contaminated gaseous medium has passed said exhaust flow zone.