Patent ID: 7947123

Claim:
An air cleaning system comprising: a duct; an air mover associated with said duct for moving air through said duct; and an impact filter in air flow communication with said duct, said impact filter including: an entrance panel defining a nozzle having a nozzle diameter, said nozzle having a length to accelerate an air stream and contaminants entrained in the air stream to similar velocities; an outlet panel overlying said entrance panel and defining an outlet; said panels associated one with the other and defining an indirect airflow path from said nozzle to said outlet; an impact surface confronting said nozzle in spaced relation, said impact surface spaced from said nozzle by a distance of between about one-half said nozzle diameter and ten times said nozzle diameter; a baffle associated with said impact surface for guiding air away from said impact surface on one side of said baffle; and a contaminant trough on an opposite side of said baffle and associated with said impact surface and said baffle, said contaminant trough being substantially enclosed, and having a contaminant entrance defined by a space between said impact surface and said baffle, said space between said impact surface and said baffle being larger than said distance between said impact surface and said nozzle, said baffle separating an air flow stream on said one side of said baffle from said contaminant trough on said opposite side of said baffle.