Description
Class F01N : GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
Subclass 1/12: Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling using spirally- or helically-shaped channels (F01N 1/1 takes precedence; cyclones B04C)