Image Number 3 for United States Patent #4290786.
An apparatus for removing particulate matter from a gas stream includes a sorbent injector, a charging antenna, and a plurality of granular media filter cells. The gas stream containing the particulate matter is directed through an inlet plenum. The sorbent injector, located within the inlet plenum, injects fine particles of a sorbent material toward the charging antenna for electrostatically charging the sorbent particles. The charged sorbent particles form a large charged surface area for inducing charges on the particulate matter entrained by the gas stream. The plurality of filter cells each include inner and outer perforated, concentric cylinders, and granular media is caused to move downward between the inner and outer cylinders of each filter cell. The gas stream, including the entrained particulate matter and sorbent particles, flows through the perforations in the inner cylinder into the granular media; the entrained particulate matter and sorbent particles become attached to the granular media as a result of inertial impact forces and electrostatic charges. Clean gas leaves the granular media through the perforations in the outer cylinder.