CASCADE IMPACTOR WITH INDIVIDUALLY DRIVEN IMPACTOR PLATES

摘要

A cascade impactor (10) has a series of vertically stacked impactor housing sections (12,14,16). Each of the impactor housing sections (12,14,16) has an upper portion that supports a motor (50) for driving an impactor plate (58) that is positioned below a nozzle plate (38B,40B,42B) through which flow passes. Each housing section (12,14,16) also has an outlet passageway (30) leading to a lower impactor chamber (24) for the next in a series of impactor chambers (24), except the last outlet passageway opens through a filter (68) to exhaust. The impactor chambers (24) are defined by a skirt (22) that seals on the neck (18) of the next downstream housing section (12, 14, 16) The impactor plates (58) are each driven by a separate motor (50), and held onto a hub (52) on the motor output shaft with a magnetic coupling (54,56) so the impactor plates (58) can be removed when the housing sections (12,14,16) are separated.