APPARATUS AND METHOD FOR CLEANING AN AIR FILTER UNIT

摘要

Shown is an apparatus and method for cleaning filter units of an air filtering system using a reverse flow pulse of pressurized air. The filter cleaning system includes a venturi element (36) with a narrowed throat portion (56). A blowpipe (46) is substantially axially aligned with the venturi (36) and has an outlet nozzle (50) that is flared in a substantially conical shape with an included angle that (64) that exceeds an angle at (62) at which high pressure air would ordinarily diverge from an unmodified blowpipe opening. The nozzle (50) is axially spaced from the venturi at a selected distance (70) such that a high velocity pulse of air delivered by the blowpipe (46) through the nozzle (50) is delivered to the outlet portion (58) of the venturi (36) substantially between the outlet opening (62) and the throat (56). This relationship provides a cleaning pulse of air that effectively completely chokes all forward movement of air flow through the venturi (36) and delivers a pulse wave of high pressure, high velocity air along substantially the full length of the tubular filter element (22).