Apparatuses and methods for a closed crankcase ventilation system of an internal combustion engine

Abstract

Described herein are engine systems, closed crankcase ventilation systems, and hot filter assemblies that are configured to filter out contaminants from the closed crankcase ventilation system prior to being returned to an air intake of the engine system. In some examples, a closed crankcase ventilation system can include an engine comprising a crankcase, an oil separator coupled to the crankcase, and a hot filter assembly coupled to the oil separator and mounted to an exhaust manifold of the engine or a turbine housing of a turbocharger. The hot filter assembly comprises a housing defining a cavity, a gas inlet fluidly coupled between the oil separator and the cavity, a gas outlet fluidly coupled between the cavity and an air intake of the engine, and at least one baffle extending across the cavity and defining a first and second gas pathways on opposite sides of the baffle.

We claim: 
     
         1 . A closed crankcase ventilation system, comprising:
 an engine comprising a crankcase;   an oil separator coupled to the crankcase and configured to separate oil from blow-by gases received from the crankcase; and   a hot filter assembly coupled to the oil separator and mounted to an exhaust manifold of the engine or a turbine housing of a turbocharger, the hot filter assembly comprising:
 a housing defining an interior cavity of the hot filter assembly; 
 a gas inlet fluidly coupled between the oil separator and the interior cavity; 
 a gas outlet fluidly coupled between the interior cavity and an air intake of the engine; and 
 at least one baffle that extends across the interior cavity and defines a first gas pathway along a first side of the at least one baffle and a second gas pathway along a second side of the at least one baffle, wherein gases flow through the first gas pathway in a first direction and gases flow through the second gas pathway in a second direction that is opposite the first gas pathway. 
   
     
     
         2 . The closed crankcase ventilation system of  claim 1 , further comprising a first pressure sensor at or upstream of the gas inlet of the hot filter assembly, and a second pressure sensor at or downstream of the gas outlet of the hot filter assembly. 
     
     
         3 . The closed crankcase ventilation system of  claim 1 , wherein the housing of the hot filter assembly is coupled directly to an outer surface of the exhaust manifold of the engine such that heat from hot exhaust gases traveling through the exhaust manifold transfers across walls of the housing to gases flowing through the interior cavity of the hot filter assembly. 
     
     
         4 . The closed crankcase ventilation system of  claim 1 , further comprising a wire mesh filter arranged inside the interior cavity. 
     
     
         5 . The closed crankcase ventilation system of  claim 1 , wherein the at least one baffle includes two or more baffles spaced apart from one another and extending from opposite sidewalls of the housing in an alternating arrangement. 
     
     
         6 . The closed crankcase ventilation system of  claim 1 , wherein the at least one baffle extends between a rear interior wall and a front interior wall of the housing and further extends from a first interior sidewall toward a second interior sidewall of the housing, wherein the first and second interior sidewalls extend between the rear and front interior walls. 
     
     
         7 . The closed crankcase ventilation system of  claim 1 , wherein the at least one baffle extends across a majority of the interior cavity in either a longitudinal direction or a horizontal direction. 
     
     
         8 . A hot filter assembly for an engine system, comprising:
 a metal housing comprising interior walls that define an interior cavity of the hot filter assembly, the interior walls comprising at least a rear interior wall, a first interior sidewall, and a second interior sidewall, and wherein the interior cavity is further defined by a front interior wall of the hot filter assembly;   a first opening in communication with the interior cavity;   a second opening in communication with the interior cavity; and   at least one baffle arranged inside the interior cavity and extending from the rear interior wall to the front interior wall of the hot filter assembly, wherein the at least one baffle has an attached end attached to the first interior sidewall of the housing and a free end, and wherein the at least one baffle extends from the first interior sidewall toward the second interior sidewall of the metal housing such that gases entering the interior cavity through the first opening flow along a first side of the at least one baffle, around the free end, and across a second side of the at least one baffle to exit the metal housing through the second opening, wherein the first interior sidewall and the second interior sidewall each extend between the rear interior wall and the front interior wall.   
     
     
         9 . The hot filter assembly of  claim 8 , wherein the first and second interior sidewalls are opposite one another across the interior cavity. 
     
     
         10 . The hot filter assembly of  claim 9 , wherein the first and second interior sidewalls are adjacent and extend perpendicular to one another with the second interior sidewall connected to a first end portion of the first interior sidewall, and wherein the attached end of the at least one baffle is attached to a second end portion of the first interior sidewall and the free end of the at least one baffle is adjacent to but spaced away from the second interior sidewall. 
     
     
         11 . The hot filter assembly of  claim 8 , further comprising a wire mesh filter disposed inside the interior cavity. 
     
     
         12 . The hot filter assembly of  claim 8 , wherein the metal housing comprises cast iron, and wherein the hot filter assembly is formed as one piece. 
     
     
         13 . The hot filter assembly of  claim 8 , wherein the housing is open on one side and further comprising a cover coupled to the open side of the housing and defining the front interior wall of the hot filter assembly. 
     
     
         14 . An engine system, comprising:
 an engine comprising a crankcase and an exhaust manifold;   a turbocharger comprising a compressor and a turbine;   an oil separator configured to receive blow-by gases from the crankcase and separate oil from the blow-by gases;   the hot filter assembly of  claim 8  coupled to the exhaust manifold of the engine or a housing of the turbine;   a first conduit connecting the oil separator to the hot filter assembly, the first conduit configured to route the separated blow-by gases from the oil separator to the hot filter assembly; and   a second conduit connecting the hot filter assembly to an air inlet upstream of the compressor, the second conduit configured to route cleaned and dried gases from the hot filter assembly to the air inlet.   
     
     
         15 . The engine system of  claim 14 , wherein the hot filter assembly is coupled directly to an outer surface of the exhaust manifold or an outer surface of the housing of the turbine. 
     
     
         16 . The engine system of  claim 14 , wherein the first conduit is a wire mesh tube comprising an outer tubing layer and an inner mesh layer, and wherein an inner diameter of the wire mesh tube is 20-30 mm and a length of the wire mesh tube is 450-550 mm. 
     
     
         17 . The engine system of  claim 14 , further comprising an air filter arranged upstream of the compressor, and wherein the air inlet to which the second conduit connects is an inlet to the air filter. 
     
     
         18 . A method of operating a turbocharger for an internal-combustion engine, comprising:
 routing gases that emanate from a crankcase of the engine through an oil separator and a hot filter assembly, wherein the hot filter assembly is configured to output remaining gases including particulate matter;   directing the remaining gases from the hot filter assembly to a turbocharger;   forming, via the particulate matter in the remaining gases, an abradable layer on at least a portion of an inlet surface of the turbocharger; and   abrading, via one or more blades of a compressor of the turbocharger, the abradable layer to form an abraded surface layer between the inlet surface and the one or more blades.   
     
     
         19 . The method of  claim 18 , further comprising:
 repeating routing of the gases, the directing of the remaining gases, the forming of the abradable layer, and the abrading of the abradable layer to maintain the abraded surface layer between the inlet surface and the one or more blades.   
     
     
         20 . The method of  claim 18 , wherein the hot filter assembly is configured to output the remaining gases with the particulate matter having a size of less than or equal to 1 micron.