US Patent 6955162 Internal combustion engine with pressure boosted exhaust gas recirculation

An exhaust gas recirculating system for a turbocharged diesel engine utilizes an electrically driven compression pump to boost exhaust gas pressure before return to the engine induction system. Exhaust gas is drawn from the exhaust system or stack some distance removed and downstream from the outlet from the exhaust turbine, compressed to overcome the intake manifold boost pressure, and returned to the intake system along an extended pipe to cool the gas. The compressor is energized from the vehicle battery during periods of demand for peak pressure demand on the engine thereby recycling recaptured energy from the battery to boost engine output. Exhaust turbine performance during periods of peak loading is also improved.