Patent ID: 7739869

Claim:
A method for reducing particulate emissions from engine exhaust, comprising: Placing an acoustic generator on the exhaust line downstream the engine; Wherein the acoustic generator is tube-shaped having a top end, a bottom end, and a long wall, the acoustic generator further having a first transducer at the top end and a second transducer at the bottom end, the acoustic generator further having an entry port in its long wall near the bottom end for receiving engine exhaust and an exit port in its long wall near the top end for exhausting the engine exhaust; Placing a particulate filter proximate the exit port; generating mechanical waves in the exhaust line upstream the filter, such that the first transducer emits acoustic waves from the top end and the second transducer emits acoustic waves from the bottom end, thereby producing interfering standing waves along the length of the acoustic generator; and using the particulate filter to filter the engine exhaust.