Pollution control system for diesel engine

Abstract

A pollution control system for a diesel engine includes a PCV valve and an associated vacuum pump having an inlet and an outlet adapted to vent blow-by gas out from a crankcase to an intake manifold on the diesel engine. The vacuum pump associated with the PCV valve selectively modulates vacuum pressure to adjustably increase or decrease a fluid flow rate of blow-by gas venting from the crankcase through the PCV valve.

What is claimed is: 
     
         1 . A pollution control system for a diesel engine, comprising:
 a PCV valve having an inlet fluidly connected to a crankcase on the diesel engine and an outlet fluidly connected to an intake manifold on the diesel engine;   a vacuum pump associated with the PCV valve; and   a controller for selectively operating the vacuum pump to increase vacuum pressure on an intake manifold side of the PCV valve relative to a pressure on a crankcase side of the PCV valve based, in part, on measurements from an engine sensor.   
     
     
         2 . The system of  claim 1 , wherein the vacuum pump lessens vacuum pressure on the intake manifold side during periods of decreased blow-by gas production to decrease the fluid flow rate through the PCV valve, and increases vacuum pressure on the intake manifold side during periods of increased blow-by gas production to increase the fluid flow rate through the PCV valve. 
     
     
         3 . The system of  claim 2 , wherein the vacuum pump is fluidly disposed between the PCV valve and the intake manifold. 
     
     
         4 . The system of  claim 2 , wherein controller operates the vacuum pump in real-time. 
     
     
         5 . The system of  claim 1 , wherein the engine sensor comprises at least one of an engine temperature sensor, an accelerometer sensor, an exhaust sensor, a battery sensor, a PCV valve sensor, a cam position sensor, and/or an engine RPM sensor. 
     
     
         6 . The system of  claim 1 , wherein the engine sensor comprises a cam position sensor to determine RPMs of the engine. 
     
     
         7 . The system of  claim 1 , further comprising an oil trap fluidly coupled to the PCV valve for condensing vaporized oil in the blow-by gas into a liquid for reuse in the crankcase. 
     
     
         8 . The system of  claim 7 , wherein a volume of the oil trap is relatively larger than a volume of a vent line carrying the blow-by gas to the oil trap from the crankcase. 
     
     
         9 . The system of  claim 8 , including a drain line coupled to the oil trap for returning liquid oil to the crankcase. 
     
     
         10 . The system of  claim 9 , wherein the vent line and the drain line couple to different portions of the oil trap such that the vacuum drawing the blow-by gas through the oil trap does not interfere with the drainage of the liquid oil back to the crankcase. 
     
     
         11 . The system of  claim 9 , wherein the drain line couples to the crankcase via a dipstick chamber. 
     
     
         12 . The system of  claim 7 , wherein the oil trap includes an internal oil filter. 
     
     
         13 . The system of  claim 1 , further comprising an exhaust diverter fluidly connecting an exhaust outlet on the diesel engine to the intake manifold. 
     
     
         14 . The system of  claim 10 , wherein the controller selectively operates the exhaust diverter to divert a portion of exhaust gases from the exhaust outlet to the intake manifold based, in part, on measurements from an exhaust analyzer. 
     
     
         15 . A pollution control system for a diesel engine, comprising:
 a PCV valve having an inlet fluidly connected to a crankcase on the diesel engine and an outlet fluidly connected to an intake manifold on the diesel engine;   a vacuum pump fluidly disposed between the PCV valve and the intake manifold; and   a controller for selectively operating the vacuum pump to increase vacuum pressure on an intake manifold side of the PCV valve relative to a pressure on a crankcase side of the PCV valve based, in part, on measurements from an engine sensor comprising at least one of an engine temperature sensor, an accelerometer sensor, an exhaust sensor, a battery sensor, a PCV valve sensor, a cam position sensor, and/or an engine RPM sensor;   wherein the vacuum pump lessens vacuum pressure on the intake manifold side during periods of decreased blow-by gas production to decrease the fluid flow rate through the PCV valve, and increases vacuum pressure on the intake manifold side during periods of increased blow-by gas production to increase the fluid flow rate through the PCV valve.   
     
     
         16 . The system of  claim 15 , wherein controller operates the vacuum pump in real-time. 
     
     
         17 . The system of  claim 15 , wherein the engine sensor comprises a cam position sensor to determine RPMs of the engine. 
     
     
         18 . The system of  claim 15 , further comprising an oil trap fluidly coupled to the PCV valve for condensing vaporized oil in the blow-by gas into a liquid for reuse in the crankcase, wherein a volume of the oil trap is relatively larger than a volume of a vent line carrying the blow-by gas to the oil trap from the crankcase. 
     
     
         19 . The system of  claim 18 , including a drain line coupled to the oil trap for returning liquid oil to the crankcase. 
     
     
         20 . The system of  claim 19 , wherein the vent line and the drain line couple to different portions of the oil trap such that the vacuum drawing the blow-by gas through the oil trap does not interfere with the drainage of the liquid oil back to the crankcase. 
     
     
         21 . The system of  claim 19 , wherein the drain line couples to the crankcase via a dipstick chamber. 
     
     
         22 . The system of  claim 18 , wherein the oil trap includes an internal oil filter. 
     
     
         23 . The system of  claim 1 , further comprising an exhaust diverter fluidly connecting an exhaust outlet on the diesel engine to the intake manifold, wherein the controller selectively operates the exhaust diverter to divert a portion of exhaust gases from the exhaust outlet to the intake manifold based, in part, on measurements from an exhaust analyzer.