Filter device for removing particulate material from gases

Claim 1

A filter device for removing particles from a particle-laden gas, said filter device comprising an inlet duct arranged to provide a downward flow therethrough of a particle-laden gas, a plurality of filter units distributed about said inlet duct, a plurality of vertical plates radiating outwardly from a central region which is vertically below the bottom of the inlet duct, said plates defining between them a ring of decelaration chambers which are wedge-shaped and have inner narrow sides and outer wider sides, the inner narrow sides of said deceleration chambers being vertically below the bottom of said inlet duct, said deceleration chambers having inlets which are at the tops of their inner sides and vertically below the bottom of said inlet duct and receive particle-laden gas from said inlet duct, each of said deceleration chambers having at the top of a wider part thereof a gas exit to at least one of said filter units and having at its bottom a removed particle exit, whereby particle-laded gas entering each deceleration chamber first moves towards said removed particle exit and then substantially reverses its flow direction to exit through said gas exit, leaving behind some large particles at the bottom of that deceleration chamber, a first baffle mounted to be turned about a substantially vertical axis so as to pass above and close to said inlets and close off said inlets successively and at least one at a time as said first baffle is turned, an outlet duct, suction means coupled to said outlet duct, said outlet duct positioned and arranged to carry away particles removed from said deceleration chambers and said filter units via said removed particle exits by said suction means coupled to said outlet duct, a second baffle mounted to be turned about a substantially vertical axis and thereby provide communication of said removed particle exits at least one at a time to said outlet duct while the other removed particle exits are closed off from said outlet duct, and drive means for turning said first and second baffles in synchronism so that when the inlet of one deceleration chamber is closed off from said inlet duct the removed particle exit of the same deceleration chamber is in communication with said outlet duct.