Patents by Inventor Rahul Mital

Rahul Mital has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7758676
    Abstract: A control system for particulate filters is provided. The control system for a particulate filter includes a clean filter estimating module that estimates a clean pressure based on a first pressure in the particulate filter within a predetermined period of a regeneration event. A soot prediction module estimates a level of soot in the particulate filter based on a comparison of the first pressure and a second pressure in the particulate filter received after the predetermined period.
    Type: Grant
    Filed: October 3, 2006
    Date of Patent: July 20, 2010
    Inventors: Rahul Mital, Chad E. Marlett, James R Ireton, Jr., Thomas E Wiseman
  • Publication number: 20090282816
    Abstract: An engine system includes a diesel engine having an exhaust manifold connected to the diesel engine. An exhaust passage is connected to the exhaust manifold and a diesel particulate filter is disposed in the exhaust passage. An air intake passage is provided for supplying fresh air to the diesel engine. A bypass passage is connected between the air intake passage and the exhaust passage in a location downstream of the diesel particulate filter. The bypass passage includes a bypass control valve for opening and closing the bypass passage during a diesel particulate filter regeneration cycle when the vehicle is at low speed or idle.
    Type: Application
    Filed: May 19, 2008
    Publication date: November 19, 2009
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Jianwen Li, Rahul Mital, Michael Christopher Luckham, Sameer Bhargava
  • Publication number: 20090235653
    Abstract: A particulate matter (PM) filter assembly includes a PM filter that filters PM from an exhaust stream and that includes an entry face facing a first direction of flow of the exhaust stream, and a swirl element disposed in the exhaust stream and that includes a blade that directs a portion of the exhaust stream in a second direction of flow that is different than the first direction of flow. The blade directs the portion of the exhaust stream to distribute the exhaust stream over a frontal area of the entry face of the PM filter. A related method of filtering particulate matter from an exhaust stream is also provided.
    Type: Application
    Filed: October 15, 2008
    Publication date: September 24, 2009
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC
    Inventors: Rahul Mital, David B. Brown, Jianwen Li, Michael Christopher Luckham, Kevin B. Fuqua, Kasser A. Jaffri, Linda Garcia
  • Publication number: 20080250776
    Abstract: A mixing apparatus mountable within a generally cylindrical passage defined by an exhaust gas conduit of an exhaust gas after-treatment system is provided. The passage includes an outer region and an inner region operable to convey an exhaust stream and a liquid stream, such as a urea stream. The mixing apparatus includes a retainer ring operable to retain the mixing apparatus within the passage. A first plurality of fins extends from the retainer ring and is operable to impart a rotational velocity component in a first direction to the exhaust stream and urea stream in the outer region of the passage. A second plurality of fins extends from the retainer ring and is operable to impart a rotational velocity component in a second direction, opposite the first direction, to the exhaust stream and urea stream in the inner region of the passage.
    Type: Application
    Filed: April 16, 2007
    Publication date: October 16, 2008
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: David B. Brown, Rahul Mital, Kasser A. Jaffri, Kevin B. Fuqua
  • Publication number: 20080196408
    Abstract: The present invention provides an exhaust cooler mounted to a tailpipe for receiving exhaust gas. The exhaust cooler includes a jet pump connectable to the tailpipe and a nozzle connectable to the tailpipe. The nozzle defines a nozzle opening between the tailpipe and the jet pump for communicating the exhaust gas from the tailpipe to the jet pump. A first member is included that is moveable between a closed position and an open position, the open position defining a first opening between the tailpipe and the jet pump for communicating the exhaust gas from the tailpipe to the jet pump.
    Type: Application
    Filed: February 21, 2007
    Publication date: August 21, 2008
    Applicant: GM Global Technology Operations, Inc.
    Inventors: Jianwen Li, Rahul Mital
  • Patent number: 7377101
    Abstract: The invention provides a NOx adsorber aftertreatment system for internal combustion engines which utilizes a plasma fuel converter operatively coupled to at least one NOx adsorber to aid in the regeneration of the NOx adsorber. Fuel and engine exhaust is injected into a plasma fuel converter upstream of a NOx absorber producing reductant such as H2, and CO, which are inlet into the NOx absorber. Reductants such as H2 and CO acting along and together help to efficiently regenerate the NOx Adsorber which in turn releases exhausts products such as CO2 and N2. Using the reductants generated by the plasma fuel converter NOx adsorbers, catalytic soot filter, and the like can be regenerated at exhaust temperatures less than 250° C. The plasma fuel converter, NOx adsorber regenerating aftertreatment system of the present invention may be used with any suitable control system.
    Type: Grant
    Filed: February 13, 2004
    Date of Patent: May 27, 2008
    Assignee: Fleetguard, Inc.
    Inventors: Rahul Mital, Bradlee J. Stroia, Robert C. Yu
  • Publication number: 20080078236
    Abstract: A control system for particulate filters is provided. The control system for a particulate filter includes a clean filter estimating module that estimates a clean pressure based on a first pressure in the particulate filter within a predetermined period of a regeneration event. A soot prediction module estimates a level of soot in the particulate filter based on a comparison of the first pressure and a second pressure in the particulate filter received after the predetermined period.
    Type: Application
    Filed: October 3, 2006
    Publication date: April 3, 2008
    Inventors: Rahul Mital, Chad E. Marlett, James R. Ireton, Thomas E. Wiseman
  • Publication number: 20080047258
    Abstract: An exhaust after-treatment system for an internal combustion engine includes a lean NOx catalyst having an exhaust stream from the internal combustion engine flowing therethrough. A NOx absorber catalyst is downstream of the lean NOx catalyst. The NOx absorber is selectively regenerated to increase a NOx reduction efficiency of the exhaust after-treatment system.
    Type: Application
    Filed: August 24, 2006
    Publication date: February 28, 2008
    Inventor: Rahul Mital
  • Publication number: 20070175206
    Abstract: The present invention provides for an NOx adsorber aftertreatment system for internal combustion engines which utilizes a parallel arrangement of an adsorber catalyst and a bypass. The exhaust flow from the engine is routed through the adsorber during lean operation. At a predetermined regeneration time (for example, when the adsorber catalyst is 20% full), the exhaust gas flow is reduced through the parallel leg that contains the adsorber catalyst to be regenerated (e.g., 20% through the catalyst leg, 80% of the flow to the bypass leg). A quantity of hydrocarbon is injected into the reduced-flow catalyst leg in order to make the mixture rich. Since the flow has been reduced in this leg, only a small fraction of the amount of hydrocarbon that would have been required to make the mixture rich during full flow is required. This will result in a substantial reduction in the fuel penalty incurred for regeneration of the adsorber catalyst.
    Type: Application
    Filed: October 10, 2006
    Publication date: August 2, 2007
    Inventors: Rahul Mital, Bradlee Stroia, Scott Cole
  • Publication number: 20070048204
    Abstract: A flash injection system for ammonia selective catalytic reduction aftertreatment of engine exhaust gases includes a tank for storing aqueous urea. An injection nozzle is disposed in an exhaust conduit of the engine, which conducts an exhaust stream from the engine. A fluid line conducts the aqueous urea between the tank and the nozzle. A pump is coupled with the fluid line for pressurizing the aqueous urea. A heater is also coupled with the fluid line for heating the aqueous urea that is pressurized by the pump. A valve is operatively connected to the fluid line for controlling injection of aqueous urea through the nozzle into the exhaust stream. Injecting heated, pressurized aqueous urea into the exhaust stream causes the aqueous urea to rapidly atomize due to the decrease in pressure across the nozzle. The system is operative to convert NOx gases produced by diesel internal combustion engines into nitrogen.
    Type: Application
    Filed: September 1, 2005
    Publication date: March 1, 2007
    Inventor: Rahul Mital
  • Patent number: 7117667
    Abstract: The present invention provides for an NOx adsorber aftertreatment system for internal combustion engines which utilizes a parallel arrangement of an adsorber catalyst and a bypass. The exhaust flow from the engine is routed through the adsorber during lean operation. At a predetermined regeneration time (for example, when the adsorber catalyst is 20% full), the exhaust gas flow is reduced through the parallel leg that contains the adsorber catalyst to be regenerated (e.g., 20% through the catalyst leg, 80% of the flow to the bypass leg). A quantity of hydrocarbon is injected into the reduced-flow catalyst leg in order to make the mixture rich. Since the flow has been reduced in this leg, only a small fraction of the amount of hydrocarbon that would have been required to make the mixture rich during full flow is required. This will result in a substantial reduction in the fuel penalty incurred for regeneration of the adsorber catalyst.
    Type: Grant
    Filed: August 28, 2003
    Date of Patent: October 10, 2006
    Assignee: Fleetguard, Inc.
    Inventors: Rahul Mital, Bradlee J. Stroia, Scott Cole
  • Publication number: 20060201142
    Abstract: A diesel engine system having an exhaust system with a catalyst and a diesel particulate filter includes a first module that determines a light-off temperature of the catalyst based on an exhaust flow rate (EFR) through the exhaust system and a second module that selectively generates an enable signal based on the light-off temperature and a catalyst temperature. A DPF regeneration sequence is enabled based on said enable signal.
    Type: Application
    Filed: September 23, 2005
    Publication date: September 14, 2006
    Inventors: Chad Marlett, Rahul Mital
  • Publication number: 20050178107
    Abstract: The invention provides a NOx adsorber aftertreatment system for internal combustion engines which utilizes a plasma fuel converter operatively coupled to at least one NOx adsorber to aid in the regeneration of the NOx adsorber. Fuel and engine exhaust is injected into a plasma fuel converter upstream of a NOx absorber producing reductant such as H2, and CO, which are inlet into the NOx absorber. Reductants such as H2 and CO acting along and together help to efficiently regenerate the NOx Adsorber which in turn releases exhausts products such as CO2 and N2. Using the reductants generated by the plasma fuel converter NOx adsorbers, catalytic soot filter, and the like can be regenerated at exhaust temperatures less than 250° C. The plasma fuel converter, NOx adsorber regenerating aftertreatment system of the present invention may be used with any suitable control system.
    Type: Application
    Filed: February 13, 2004
    Publication date: August 18, 2005
    Inventors: Rahul Mital, Bradlee Stroia, Robert Yu
  • Publication number: 20050178110
    Abstract: The invention provides a NOx adsorber aftertreatment system for internal combustion engines which utilizes at least one precat operatively coupled to at least one NOx adsorber to aid in the regeneration of the NOx adsorber. Fuel is injected into a precat located upstream of a NOx absorber producing heat, H2O, and reductants such as CO, HC, and volatile hydrocarbons, which are input into the NOx absorber. The combination of heat, water, and reductants help to efficiently regenerate the NOx Adsorber which in turn releases exhausts products such as CO2 and N2. Regeneration of a NOx adsorber can be performed during periods of reduced exhaust gas flow lowering the fuel penalty associated with NOx adsorber regeneration. The pre-cat, NOx adsorber regenerating aftertreatment system of the present invention may be used with any suitable control system.
    Type: Application
    Filed: February 12, 2004
    Publication date: August 18, 2005
    Inventors: Rahul Mital, Bradlee Stroia, S. Huang, Robert Yu
  • Patent number: 6922987
    Abstract: The present invention provides for a system and process for enhancing internal combustion engine aftertreatment applications by superheated fuel injection. The system includes a fuel supply upstream of a fuel injector of an aftertreatment application. The system also includes a heater for heating the fuel in the fuel supply. A temperature controller can be used to maintain the heated fuel in a liquid form. When liquid fuel in the pressurized fuel supply is heated, then upon exiting the injector the pressure of the fuel drops rapidly, resulting in atomization of the liquid. The vaporized fuel thereby produced is comprised of extremely small droplets and is elevated in temperature, which reduces the possibility of condensation on internal surfaces of the aftertreatment system. This fine droplet size and resistance to condensation enhances the NOx conversion efficiency of adsorbers. Problems related to premature aging of catalysts and fuel penalties can also be reduced.
    Type: Grant
    Filed: February 12, 2003
    Date of Patent: August 2, 2005
    Assignee: Fleetguard, Inc.
    Inventors: Rahul Mital, Scott Cole, Robert C. Yu, Mike Nagel
  • Patent number: 6820414
    Abstract: The present invention provides for adsorber catalysts arranged in parallel. The exhaust flow from the engine is divided in a predetermined ratio between the two catalysts during lean operation (e.g. 50-50). At a predetermined regeneration time (for example, when the adsorber catalyst is 20% full), the exhaust gas flow is reduced through the parallel leg that is to be regenerated (e.g. 20-80). A quantity of hydrocarbon is injected into the reduced-flow leg in order to make the mixture rich. Once the leg has been regenerated, the flow distribution between the parallel legs is reversed, and the other catalyst leg is regenerated while the other side (which is now clean) receives the majority of the exhaust flow. Once both catalyst legs have been regenerated, the exhaust flow is adjusted back to normal (e.g. 50-50) until the catalysts are again ready for regeneration and reduction. A catalytic soot filter is positioned downstream from the adsorber.
    Type: Grant
    Filed: July 11, 2002
    Date of Patent: November 23, 2004
    Assignee: Fleetguard, Inc.
    Inventors: Bradlee J. Stroia, Robert C. Yu, Rahul Mital, Michael J. Cunningham
  • Publication number: 20040154287
    Abstract: The present invention provides for a system and process for enhancing internal combustion engine aftertreatment applications by superheated fuel injection. The system includes a fuel supply upstream of a fuel injector of an aftertreatment application. The system also includes a heater for heating the fuel in the fuel supply. A temperature controller can be used to maintain the heated fuel in a liquid form. When liquid fuel in the pressurized fuel supply is heated, then upon exiting the injector the pressure of the fuel drops rapidly, resulting in atomization of the liquid. The vaporized fuel thereby produced is comprised of extremely small droplets and is elevated in temperature, which reduces the possibility of condensation on internal surfaces of the aftertreatment system. This fine droplet size and resistance to condensation enhances the NOx conversion efficiency of adsorbers. Problems related to premature aging of catalysts and fuel penalties can also be reduced.
    Type: Application
    Filed: February 12, 2003
    Publication date: August 12, 2004
    Inventors: Rahul Mital, Scott Cole, Robert C. Yu, Mike Nagel
  • Patent number: 6745560
    Abstract: Exhaust flow from an internal combustion engine is divided in a predetermined ratio between two adsorber catalysts arranged in parallel during lean operation. A regeneration cycle time is predetermined and regeneration is accomplished by injecting hydrocarbons into a catalyst leg having a reduced exhaust flow. Upon regeneration of the catalyst, the exhaust gas flow distribution is reversed and the opposite catalyst is regenerated while the regenerated catalyst bears the brunt of the exhaust flow. The exhaust flow then reverts to a normal (e.g. 50—50) flow distribution until another regeneration cycle is warranted. A catalytic soot filter placed upstream of each adsorber is also regenerated by hydrocarbon injection. The addition of the catalytic soot filter provides more time and surface area for the hydrocarbon to react with the oxygen. Some of the diesel fuel is reformulated into hydrogen and carbon monoxide for superior regeneration.
    Type: Grant
    Filed: July 11, 2002
    Date of Patent: June 8, 2004
    Assignee: Fleetguard, Inc.
    Inventors: Bradlee J. Stroia, Robert C. Yu, Rahul Mital, Michael J. Cunningham
  • Patent number: 6735940
    Abstract: The present invention provides for an NOx adsorber aftertreatment system for internal combustion engines which utilizes adsorber catalysts arranged in parallel. The exhaust flow from the engine is divided in a predetermined ratio between the two catalysts during lean operation (e.g. 50-50). At a predetermined regeneration time (for example, when the adsorber catalyst is 20% full), the exhaust gas flow is reduced through the parallel leg that is to be regenerated (e.g., 20% through the leg to be regenerated, 80% of the flow to the other leg). A quantity of hydrocarbon is injected into the reduced-flow leg in order to make the mixture rich. Since the flow has been reduced in this leg, only a small fraction of the amount of hydrocarbon that would have been required to make the mixture rich during full flow is required. This will result in a substantial reduction in the fuel penalty incurred for regeneration of the adsorber catalyst.
    Type: Grant
    Filed: July 11, 2002
    Date of Patent: May 18, 2004
    Assignee: Fleetguard, Inc.
    Inventors: Bradlee J. Stroia, Michael J. Cunningham, Rahul Mital, Scott Cole
  • Publication number: 20040037755
    Abstract: The present invention provides for an NOx adsorber aftertreatment system for internal combustion engines which utilizes a parallel arrangement of an adsorber catalyst and a bypass. The exhaust flow from the engine is routed through the adsorber during lean operation. At a predetermined regeneration time (for example, when the adsorber catalyst is 20% full), the exhaust gas flow is reduced through the parallel leg that contains the adsorber catalyst to be regenerated (e.g., 20% through the catalyst leg, 80% of the flow to the bypass leg). A quantity of hydrocarbon is injected into the reduced-flow catalyst leg in order to make the mixture rich. Since the flow has been reduced in this leg, only a small fraction of the amount of hydrocarbon that would have been required to make the mixture rich during full flow is required. This will result in a substantial reduction in the fuel penalty incurred for regeneration of the adsorber catalyst.
    Type: Application
    Filed: August 28, 2003
    Publication date: February 26, 2004
    Inventors: Rahul Mital, Bradlee J. Stroia, Scott Cole