Diesel engine exhaust gas recirculation system for NO.sub.x control incorporating a compressed air regenerative particulate control system
First Claim
1. A system for reducing nitrogen oxide (NOx) and total particulate emissions in diesel exhaust from a diesel engine comprising:
- a diesel engine exhaust gas flow path having a diesel exhaust inlet port couplable to a diesel engine and a diesel exhaust outlet port couplable to ambient;
a regenerable filter having pores sized to capture particles therewithin that are contained in the diesel exhaust, said filter located downstream of said diesel exhaust inlet;
said filter having a filtration efficiency of at least ninety-five percent;
means for directing at least a portion of the diesel engine exhaust flow through said filter;
means comprising a recirculation flow path for controllably recirculating at least a portion of said filtered diesel engine exhaust flow to the diesel engine;
said recirculation flow path between said regenerable filter and said diesel engine having a preselected length selected to cool the recirculated diesel exhaust; and
means for regenerating said filter at periodic intervals by providing at least one pulse of compressed air to remove said particulates lodged in said filter.
4 Assignments
0 Petitions
Accused Products
Abstract
A diesel engine exhaust gas recirculation system for control of NOx emissions is disclosed in hi h total particulate (soot, condensed polynuclear aromatic and aliphatic hydrocarbons, and ash) control system is employed to filter the exhaust gas prior to reintroduction to the diesel engine. By cleaning the recirculated exhaust gas of substantially all particulates, wear on the engine due to particulate abrasion is minimized, and NOx and particulate emissions are reduced. The particulate control system includes a high efficiency ceramic monolith trap that is periodically regenerated by one or more pulses of high-pressure air that move in the opposite direction of the engine exhaust flow through the trap. In one embodiment, a portion of the filtered diesel exhaust is recirculated to the engine. In a further embodiment, the particulate control system filters a portion of the diesel exhaust in the recirculation flow path. The system can retrofit any existing diesel-powered equipment.
-
Citations
44 Claims
-
1. A system for reducing nitrogen oxide (NOx) and total particulate emissions in diesel exhaust from a diesel engine comprising:
-
a diesel engine exhaust gas flow path having a diesel exhaust inlet port couplable to a diesel engine and a diesel exhaust outlet port couplable to ambient; a regenerable filter having pores sized to capture particles therewithin that are contained in the diesel exhaust, said filter located downstream of said diesel exhaust inlet; said filter having a filtration efficiency of at least ninety-five percent; means for directing at least a portion of the diesel engine exhaust flow through said filter; means comprising a recirculation flow path for controllably recirculating at least a portion of said filtered diesel engine exhaust flow to the diesel engine; said recirculation flow path between said regenerable filter and said diesel engine having a preselected length selected to cool the recirculated diesel exhaust; and means for regenerating said filter at periodic intervals by providing at least one pulse of compressed air to remove said particulates lodged in said filter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A diesel engine exhaust gas recirculation and filtration system for reducing nitrogen oxide (NOx) and total particulate emissions in diesel exhaust from a diesel engine comprising:
-
a diesel engine exhaust gas conduit having a diesel exhaust inlet port couplable to a diesel engine and a diesel exhaust outlet port couplable to ambient; a regenerable filter having pores sized to capture particles therewithin that are contained in the diesel exhaust, said filter disposed in said diesel engine exhaust conduit between said diesel exhaust inlet port and said diesel exhaust outlet port; a recirculation conduit having an upstream inlet coupled to said diesel engine exhaust conduit between said filter and said outlet port, said recirculation conduit further having a downstream outlet coupled to an inlet to the diesel engine, a recirculation control valve being further located downstream of said filter in said recirculation conduit near said upstream inlet of said recirculation conduit; a source of compressed air controllably coupled to said diesel engine exhaust gas conduit between said filter and said diesel exhaust outlet port; a particulate disposal unit coupled to said diesel engine exhaust gas conduit between said filter and said inlet port; and a controller, operatively coupled to said source of compressed air and said recirculation control valve in said recirculation conduit, operable in a filtration mode for coupling diesel exhaust in said diesel exhaust gas conduit through said filter and directing a portion of filtered exhaust gas to said recirculation conduit and a remainder portion of filtered exhaust gas out said diesel exhaust output port, and further operable in a regeneration mode to provide at least one pulse of high-pressure air from said source of compressed air that flows through said filter in a direction that dislodges soot (laden with PAH) and ash particles that are lodged within the pores thereof and that moves the soot (laden with PAH) and ash particles into said disposal unit. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
-
-
32. A diesel engine exhaust gas recirculation and filtration system for reducing nitrogen oxide (NOx) and total particulate emissions in diesel exhaust from a diesel engine, comprising:
-
an unfiltered diesel exhaust inlet port; an unfiltered diesel exhaust gas flow path defined by an exhaust gas line coupled between said inlet port and ambient; a recirculation flow path defined by a return line having an upstream inlet located along said unfiltered exhaust gas flow path and a downstream outlet couplable to an inlet to the diesel engine; a filter having pores sized to capture particles therewithin that are contained within the diesel exhaust; a recirculation control valve located in said recirculation flow path downstream of said filter; a source of compressed air controllably coupled to said recirculation flow path; a controller operatively coupled to said source of compressed air and said recirculation control valve, said controller being operative in a filtration mode for coupling a part of diesel exhaust along said unfiltered exhaust gas flow path through said filter along said recirculation flow path and to the engine intake and further operative in a regeneration mode for providing at least one pulse of high-pressure air that flows through said filter along said regeneration flow path in a direction that dislodges the soot (laden with PAH) and ash particles that are lodged within the pores in said filter during operation in said filtration mode and that moves the soot (laden with PAH) and ash particles into said unfiltered exhaust gas flow path. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
-
Specification