Air filter aspiration and aspiration fan drive for use with exhaust treatment

Abstract

In one embodiment, a system includes: a diesel engine having an intake and an exhaust; an exhaust treatment system communicating with the exhaust and operative to treat combustion products of the engine; an intake treatment system communicating with the intake and having an air filter assembly operative to remove particles from a flow of air and to provide the flow of air to the engine; and an aspiration fan assembly having a fan mechanically driven by the engine to produce scavenging vacuum pressure, the aspiration fan assembly being operative to apply the scavenging vacuum pressure to the air filter assembly to remove particles collected in the air filter assembly.

Therefore, at least the following is claimed: 
     
         1 . A system comprising:
 a diesel engine having an intake and an exhaust;   an exhaust treatment system communicating with the exhaust and operative to treat combustion products of the engine;   an intake treatment system communicating with the intake and having an air filter assembly operative to remove particles from a flow of air and to provide the flow of air to the engine; and   an aspiration fan assembly having a fan mechanically driven by the engine to produce scavenging vacuum pressure, the aspiration fan assembly being operative to apply the scavenging vacuum pressure to the air filter assembly to remove particles collected in the air filter assembly.   
     
     
         2 . The system of  claim 1 , wherein the exhaust treatment system has a Selective Catalytic Reduction (SCR) system. 
     
     
         3 . The system of  claim 1 , wherein the fan produces the scavenging vacuum pressure without adding exhaust restriction to the system. 
     
     
         4 . The system of  claim 1 , wherein the aspiration fan assembly further comprises an aspiration drive belt operative to drive the fan. 
     
     
         5 . The system of  claim 4 , wherein the aspiration fan assembly further comprises an idler pulley engaging the aspiration drive belt and operative to drive the aspiration drive belt. 
     
     
         6 . The system of  claim 1 , wherein:
 the engine further comprises an engine drive belt, a first pulley and a second pulley, the engine drive belt engaging about and extending between the first pulley and the second pulley; and   the aspiration fan assembly further comprises a compound idler pulley having a first pulley stage and a second pulley stage, the first pulley stage being operative to engage the engine drive belt such that the compound idler pulley rotates, the second pulley stage being operative to drive the fan responsive to rotation of the first pulley stage.   
     
     
         7 . The system of  claim 6 , wherein the first pulley stage and the second pulley stage are coaxial and the second pulley stage has a longer radius than that of the first pulley stage. 
     
     
         8 . The system of  claim 7 , wherein the aspiration fan assembly further comprises a fan pulley and an aspiration drive belt, the aspiration drive belt engaging about and extending between the fan pulley and the second pulley stage of the compound idler pulley. 
     
     
         9 . The system of  claim 1 , wherein the aspiration fan assembly is operative to drive the fan at speeds in excess of 8,000 RPM. 
     
     
         10 . The system of  claim 1 , wherein:
 the air filter assembly has a pre-filter and a main filter, the pre-filter being upstream of the main filter and operative to remove particles from air drawn into the air filter assembly and to collect the particles; and   the aspiration fan assembly has an aspiration conduit operative to apply the scavenging vacuum pressure to the pre-filter such that the particles collected by the pre-filter are drawn into the aspiration conduit.   
     
     
         11 . A system comprising:
 means for performing Selective Catalytic Reduction (SCR) on combustion products of a diesel engine;   means for collecting particles from an intake flow of air for the diesel engine; and   means for removing the particles collected using scavenging vacuum pressure and without adding exhaust restriction to the system.   
     
     
         12 . The system of  claim 11 , wherein the means for collecting particles comprises means for pre-filtering the flow of air and means for filtering the flow of air. 
     
     
         13 . The system of  claim 12 , wherein the means for removing the particles removes the particles from the means for pre-filtering the flow of air. 
     
     
         14 . The system of  claim 11 , wherein the means for removing the particles comprises means for converting rotational motion to higher speed rotational motion.