Particulate trap regeneration system and method

Abstract

A particulate trap regeneration system has an exhaust pipe that is connected between an engine and a particulate trap and an air pump that is connected to the exhaust pipe near the engine. The exhaust pipe has a double-walled configuration where the exhaust travels within the pipe and air from the air pump travels within the space between the walls, capturing heat from the exhaust. This configuration also keeps the outside of the exhaust pipe cool, improving safety and durability. Because the air entering the trap is near the exhaust temperature, the burner requires less energy to raise the temperature of the particulates sufficiently to promote burning.

Description

TECHNICAL FIELD

[0001] The present invention relates to management of particulates in diesel engine exhaust, and more particularly to a particulate trap regeneration system. BACKGROUND OF THE INVENTION

[0002] As is known in the art, burning diesel fuel generates particulates that need to be filtered and contained. Diesel engine systems normally incorporate a particulate trap having a filter that captures particulates from the exhaust. However, over time, the trap becomes too full to filter exhaust effectively and requires regeneration before it can accumulate more particulate matter. Regeneration is usually conducted by burning the particulates within the trap, which requires an external burner to increase the temperature of the particulates.

[0003] Currently known systems provide a separate exhaust path and a diverter valve for temporarily diverting exhaust away from the trap during regeneration. Burning is enhanced by adding fuel, oxygen, and / or a catalyst to the particulates beca...

Examples

Embodiment Construction

[0011]FIG. 1 shows an engine system 10 that incorporates a particulate trap regeneration system 12 according to one embodiment of the invention. The engine system 10 includes an engine 14 having an exhaust manifold 16 that sends exhaust through an exhaust pipe 18. In one embodiment, the exhaust pipe 18 has a double-walled 19a, 19b structure that keeps the outside of the exhaust pipe 18 relatively cool (FIG. 2). The double walled exhaust pipe 18 also provides a space 19c between the walls for air to flow through and be heated by heat radiating through the inner wall 19b from the exhaust. Note that other exhaust pipe configurations are possible without departing from the scope of the invention as long as there are two pipe channels that share at least one wall through which heat from the exhaust in one channel is captured by air traveling through the adjoining channel.

[0012] To further promote heat transfer, the exhaust pipe 18 may include a plurality of fins 19c that extend radially...

TECHNICAL FIELD

[0001] The present invention relates to management of particulates in diesel engine exhaust, and more particularly to a particulate trap regeneration system. BACKGROUND OF THE INVENTION

[0002] As is known in the art, burning diesel fuel generates particulates that need to be filtered and contained. Diesel engine systems normally incorporate a particulate trap having a filter that captures particulates from the exhaust. However, over time, the trap becomes too full to filter exhaust effectively and requires regeneration before it can accumulate more particulate matter. Regeneration is usually conducted by burning the particulates within the trap, which requires an external burner to increase the temperature of the particulates.

[0003] Currently known systems provide a separate exhaust path and a diverter valve for temporarily diverting exhaust away from the trap during regeneration. Burning is enhanced by adding fuel, oxygen, and / or a catalyst to the particulates beca...

Examples

Embodiment Construction

[0011]FIG. 1 shows an engine system 10 that incorporates a particulate trap regeneration system 12 according to one embodiment of the invention. The engine system 10 includes an engine 14 having an exhaust manifold 16 that sends exhaust through an exhaust pipe 18. In one embodiment, the exhaust pipe 18 has a double-walled 19a, 19b structure that keeps the outside of the exhaust pipe 18 relatively cool (FIG. 2). The double walled exhaust pipe 18 also provides a space 19c between the walls for air to flow through and be heated by heat radiating through the inner wall 19b from the exhaust. Note that other exhaust pipe configurations are possible without departing from the scope of the invention as long as there are two pipe channels that share at least one wall through which heat from the exhaust in one channel is captured by air traveling through the adjoining channel.

[0012] To further promote heat transfer, the exhaust pipe 18 may include a plurality of fins 19c that extend radially...

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