Dual Wall Energy Conserving Pipes for Internal Combustion Engines

Hot exhaust gases from an engine can be used to quickly heat up catalytic converters to active temperatures if heat losses from the gases in the pipes upstream of the converters are minimized.

This paper summarizes the development of a novel dual wall exhaust pipe which demonstrated improved emission performance by quickly heating the catalytic converter to light-off temperature.

This pipe with very thin inner liner demonstrated durability on an accelerated test to the equivalent of 100,000 vehicle miles.