Patent ID: 7662346

Claim:
An exhaust filter system for a nonroad engine having an exhaust outlet to discharge an exhaust gas, comprising: a filter casing having an intake opening communicating with said exhaust outlet of said non-vehicular generator, a discharging opening, and a filter cavity communicating said intake opening with said discharging opening for guiding said exhaust gas to flow from said intake opening to said discharging opening through said filter cavity; and a filter body having an intake communicating with said exhaust outlet, a discharging outlet, and a filter cavity defined between said intake and said discharging outlet for guiding said exhaust gas to flow from said intake opening to said discharging opening through said filter cavity; a filter core comprising a plurality of tubular filtering loops which is coaxially received in said filter cavity and has a plurality of air pores distributed thereon to form a plurality of air passages for allowing said exhaust gas inletting from said intake to flow therethrough to discharge through said discharging outlet, and a plurality of tubular filtering spacers each positioned between each said two filtering loops to define a plurality of axial air passages between said filtering spacers and said filtering loops so as to communicate with said air pores thereof, wherein a plurality of air meshes are formed on said filtering spacers to communicate with said air passages; wherein said filter core is constructed by overlapping a corrugated filtering layer having said air meshes formed thereon a flat filtering layer having said air pores formed thereon to form an air filtering net and by coiling said air filtering net to form said filtering loops via said flat filtering layer and said filtering spacers via said corrugated filtering layer; wherein corrugated filtering layer has a width shorter than a width of said flat filtering layer, wherein when said corrugated filtering layer is overlapped on said flat filtering layer to form said air filtering net, a first longitudinal side edge portion of said flat filtering layer is defined to coil as center of said filter core and a second longitudinal side edge portion of said flat filtering layer is defined to coil as an outer circumferential loop of said core and a catalyzing element provided around said air pores and air passages of said filter core for chemically reacting with said exhaust gas, said exhaust gas is evenly diffused to said filter cavity through said air pores and said air meshes by passing said exhaust gas through said air passages of said filter core so as to enhance a chemical reaction of said catalyzing element with said exhaust gas.