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...

AI Technical Summary

Benefits of technology

[0005] The present invention is directed to a particulate trap regeneration system having a simplified configuration. The system includes 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. A fuel injector and a burner supply fuel and heat to the trap so that the particulates in the trap can be burned off.

[0006] The exhaust pipe includes two channels, one of which carries exhaust from the engine and the other of which carries air from the pump. The two channels have one common wall so that heat from the exhaust is absorbed by the air from the air pump. Because the air entering the trap is at the exhaust temperature, the burner requires less energy to raise the temperature of the particulates sufficiently to promote burning. In one embodiment, the exhaust pipe has a double-walled configuration where the exhaust travels within the inner portion of the pipe and the air travels within the space between the walls. This configuration also keeps the outside of the exhaust pipe cool, improving safety and durability.

[0007] By capturing the heat from the exhaust into air entering the particulate trap, the invention is efficient to operate and also has a simpler structure than currently known particulate trap regeneration systems.

Problems solved by technology

However, over time, the trap becomes too full to filter exhaust effectively and requires regeneration before it can accumulate more particulate matter.

These systems, however, tend to require complicated routing to accommodate separate flow paths for the oxygen and catalyst.

Moreover, current systems do not take advantage of the heat already existing in the exhaust and simply allow the heat to dissipate into the environment as wasted energy.

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