A Lemprex ejector is a type of Steam locomotive exhaust system developed by noted Argentinian locomotive engineer Livio Dante Porta (who died in 2003). In a steam locomotive, draft is produced in the firebox by exhausting the steam coming from the cylinders out the chimney. The Lemprex exhaust will deliver improved draughting capacity over traditional exhaust systems. However development is only at an early stage. Some work was undertaken in Brazil.
The name a stylization of LeMaitre Porta Exhaust.
References
Lemprex ejector Wikipedia(Text) CC BY-SA