Rahul Mital

US Patent:

6735940, May 18, 2004

Filed:

Jul 11, 2002

Appl. No.:

10/192910

Inventors:

Bradlee J. Stroia - Columbus IN
Michael J. Cunningham - Greenwood IN
Rahul Mital - Columbus IN
Scott Cole - Columbus IN

Assignee:

Fleetguard, Inc. - Nashville TN

International Classification:

F01N 300

US Classification:

60286, 60288, 60289, 60292, 60297, 60303

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. 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.

US Patent:

6745560, Jun 8, 2004

Filed:

Jul 11, 2002

Appl. No.:

10/192969

Inventors:

Bradlee J. Stroia - Columbus IN
Robert C. Yu - Columbus IN
Rahul Mital - Columbus IN
Michael J. Cunningham - Greenwood IN

Assignee:

Fleetguard, Inc. - Nashville TN

International Classification:

F01N 300

US Classification:

60286, 60276, 60288, 60295, 60297, 422169, 422171

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. 50â50) 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.

US Patent:

6820414, Nov 23, 2004

Filed:

Jul 11, 2002

Appl. No.:

10/193386

Inventors:

Bradlee J. Stroia - Columbus IN
Robert C. Yu - Columbus IN
Rahul Mital - Columbus IN
Michael J. Cunningham - Greenwood IN

Assignee:

Fleetguard, Inc. - Nashville TN

International Classification:

F01N 300

US Classification:

60286, 60276, 60288, 60295, 60297, 60324, 422171, 422172, 422177

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.

US Patent:

6922987, Aug 2, 2005

Filed:

Feb 12, 2003

Appl. No.:

10/364986

Inventors:

Rahul Mital - Columbus IN, US
Scott Cole - Columbus IN, US
Robert C. Yu - Columbus IN, US
Mike Nagel - Nashville TN, US

Assignee:

Fleetguard, Inc. - Nashville TN

International Classification:

F01N003/00

US Classification:

60286, 60295, 60303

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.

US Patent:

7117667, Oct 10, 2006

Filed:

Aug 28, 2003

Appl. No.:

10/651055

Inventors:

Rahul Mital - Columbus IN, US
Bradlee J. Stroia - Columbus IN, US
Scott Cole - Columbus IN, US

Assignee:

Fleetguard, Inc. - Nashville TN

International Classification:

F01N 3/00

US Classification:

60286, 60288, 60297, 60301, 60303, 60311

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. Once the leg has been regenerated, the exhaust flow is switched to flow 100% through the adsorber leg.

US Patent:

7377101, May 27, 2008

Filed:

Feb 13, 2004

Appl. No.:

10/778275

Inventors:

Rahul Mital - Columbus IN, US
Bradlee J. Stroia - Columbus IN, US
Robert C. Yu - Columbus IN, US

Assignee:

Fleetguard, Inc. - Nashville IN

International Classification:

F01N 3/00

US Classification:

60275, 60274, 60276, 60286, 60295, 60297, 60324

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 H, and CO, which are inlet into the NOx absorber. Reductants such as Hand CO acting along and together help to efficiently regenerate the NOx Adsorber which in turn releases exhausts products such as COand N. 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.

US Patent:

7757482, Jul 20, 2010

Filed:

Feb 21, 2007

Appl. No.:

11/677133

Inventors:

Jianwen Li - Canton MI, US
Rahul Mital - Rochester Hills MI, US

Assignee:

GM Global Technology Operations, Inc. - Detroit MI

International Classification:

F01N 3/00

US Classification:

60298, 60308, 60315, 60317, 60319

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.

US Patent:

7758676, Jul 20, 2010

Filed:

Oct 3, 2006

Appl. No.:

11/542688

Inventors:

Rahul Mital - Rochester Hills MI, US
Chad E. Marlett - Plymouth MI, US
Thomas E Wiseman - Canton MI, US

International Classification:

B01D 59/26

US Classification:

96113, 95 15, 95 19, 96114, 96161, 96417, 96421, 96422, 55DIG 34, 702 47

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.