Crankcase Ventilation System

Abstract

A system for venting crankcase emissions from an engine is disclosed generally comprising a crankcase emissions conduit that communicates blow-by gases from the crankcase into the exhaust flow of an exhaust conduit, which includes a venturi, via an inlet located upstream of the minimum inner diameter of the venturi in order to pump the crankcase emissions therethrough. In certain embodiments, the gases are then directed to a filter assembly, which may include a particulate filter and may include a catalyst for facilitating redox of harmful substances to create harmless compounds prior to venting them or recirculating them in the system. In certain advantageous embodiments, an auxiliary oxygen supply is provided to facilitate these burning processes.

1 . A crankcase ventilation system, comprising:
 an exhaust gas conduit through which exhaust gas flows from an engine; and   a crankcase emissions conduit through which crankcase emissions flow from the engine;   wherein said exhaust gas conduit includes a crankcase emissions inlet through which the crankcase emissions flow from said crankcase emissions conduit into said exhaust gas conduit; and   wherein said exhaust gas conduit includes a reduced portion having a minimum inner diameter, the minimum inner diameter being located downstream of said crankcase emissions inlet, for drawing the crankcase emissions therethrough.   
   
   
       2 . The system of  claim 1 , further comprising a filter assembly located downstream of the reduced portion of said exhaust gas conduit. 
   
   
       3 . The system of  claim 2 , wherein said filter assembly includes a particulate filter. 
   
   
       4 . The system of  claim 3 , wherein said filter assembly includes an oxidation catalyst. 
   
   
       5 . The system of  claim 4 , wherein said filter assembly comprises an upstream catalyst diesel particulate filter. 
   
   
       6 . The system of  claim 4 , wherein said filter assembly comprises a wall-flow catalyst diesel particulate filter. 
   
   
       7 . The system of  claim 1 , wherein said crankcase emissions conduit includes a filter. 
   
   
       8 . The system of  claim 2 , further comprising an auxiliary oxygen conduit through which oxygen flows, wherein said exhaust gas conduit has an auxiliary oxygen inlet through which the oxygen flows from said auxiliary oxygen conduit into said exhaust gas conduit. 
   
   
       9 . The system of  claim 8 , further comprising a control valve for regulating the flow of oxygen through said auxiliary oxygen inlet. 
   
   
       10 . The system of  claim 2 , further comprising
 an air inlet conduit through which inlet air is supplied to the engine; and   a recirculation conduit through which gases flow from said filter assembly to said air inlet conduit.   
   
   
       11 . The system of  claim 2 , further comprising a vent through which gas flowing from said filter assembly is vented to the atmosphere. 
   
   
       12 . The system of  claim 1 , wherein the reduced portion of said exhaust gas conduit comprises a tapered venturi. 
   
   
       13 . The system of  claim 1 , further comprising:
 a sleeve disposed in said exhaust gas conduit and through which exhaust gas flows, said sleeve having an outlet end positionable along said exhaust gas conduit to at least partly occlude said crankcase emissions inlet and movable along a portion of said exhaust gas conduit to vary the extent of occlusion of said crankcase emissions inlet in order to regulate the flow of crankcase emissions into said exhaust gas conduit; and   a streamlined body disposed in said exhaust gas conduit and positionable along said exhaust gas conduit to at least partly occlude the outlet end of said sleeve.   
   
   
       14 . The system of  claim 13 , further comprising an actuator for moving said streamlined body along said exhaust gas conduit to vary the extent of occlusion of the outlet end of said sleeve in order to regulate flow of exhaust gas out of said sleeve. 
   
   
       15 . A crankcase ventilation system, comprising:
 an exhaust gas conduit through which exhaust gas flows from an engine, said conduit having an upstream portion and a downstream portion, said upstream portion having an inlet; and   a crankcase emissions conduit through which crankcase emissions flow from the engine to said inlet and into said upstream portion of said exhaust gas conduit;   wherein said exhaust gas conduit includes a venturi portion located downstream of said upstream portion by which the pressure of the exhaust gas flowing therethrough is decreased in order to pump the crankcase emissions into said exhaust gas conduit and towards said downstream portion.   
   
   
       16 . The system of  claim 15 , further comprising a filter assembly in fluid communication with said venturi portion and downstream thereof for burning the crankcase emissions pumped through said venturi portion. 
   
   
       17 . The system of  claim 16 , wherein said filter assembly comprises an oxidation catalyst and a particulate filter for trapping and burning particulates. 
   
   
       18 . A crankcase ventilation system, comprising:
 an engine having a cylinder and a crankcase, said engine having an exhaust port through which exhaust gas is discharged from said cylinder, and a crankcase vent through which blow-by gas in said crankcase is vented therefrom;   an exhaust gas conduit in fluid communication with said exhaust port for communicating the exhaust gas therefrom, said conduit having a blow-by gas inlet and a reduced portion having a minimum inner diameter located downstream of the blow-by gas inlet;   a blow-by gas conduit in fluid communication with said crankcase vent and said blow-by gas inlet, through which conduit the blow-by gas is communicated from said crankcase into said exhaust gas conduit upstream of the minimum inner diameter of the reduced portion of said exhaust gas conduit; and   a filter assembly in fluid communication with the reduced portion of said exhaust gas conduit for receiving the exhaust and blow-by gases therefrom and burning particulates in the gases.   
   
   
       19 . The system of  claim 18 , wherein said filter assembly comprises an oxidation catalyst and a particulate filter for trapping and burning the particulates. 
   
   
       20 . A method for ventilating a crankcase, the method comprising:
 providing an exhaust conduit with a reduced portion having a minimum inner diameter;   providing a filter assembly in fluid communication with, and downstream of, the reduced portion of the exhaust conduit;   communicating exhaust gas from an engine through the exhaust conduit to the filter assembly; and   communicating crankcase emissions from the engine into the exhaust conduit upstream of the minimum inner diameter of the reduced portion of the exhaust conduit such that the flow of exhaust gas pumps the crankcase emissions through the exhaust conduit to the filter assembly.   
   
   
       21 . The method of  claim 20 , wherein the filter assembly comprises an oxidation catalyst and a particulate filter for trapping and burning particulates. 
   
   
       22 . The method of  claim 20 , further comprising the step of regulating the amount of crankcase emissions communicated into the exhaust conduit. 
   
   
       23 . The method of  claim 20 , further comprising the step of supplying an auxiliary flow of oxygen to the exhaust conduit. 
   
   
       24 . The method of  claim 20 , further comprising the step of filtering the crankcase emissions before communicating the crankcase emissions into the exhaust conduit.