Silencing apparatus characterised by method of silencing

FMECHANICAL ENGINEERING LIGHTING HEATING WEAPONS BLASTING ENGINES OR PUMPS F01Engines F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES

F01N1/00Silencing apparatus characterised by method of silencing

F01N1/003by using dead chambers communicating with gas flow passages F01N1/006comprising at least one perforated tube extending from inlet to outlet of the silencer F01N1/02by using resonance F01N1/023Helmholtz resonators F01N1/026Annular resonance chambers arranged concentrically to an exhaust passage and communicating with it F01N1/04having sound-absorbing materials in resonance chambers F01N1/06by using interference effect F01N1/065by using an active noise source F01N1/08by reducing exhaust energy by throttling or whirling F01N1/081by passing the gases through a mass of particles F01N1/082the gases passing through porous members F01N1/083using transversal baffles defining a tortuous path for the gases or successively throttling gas flow F01N1/084the gases flowing through the silencer two or more times longitudinally in opposite directions F01N1/085using a central core throttling gas passage F01N1/086having means to impart whirling motion to the gases F01N1/087using tangential inlets into a circular chamber F01N1/088using vanes arranged on gas flow path or gas flow tubes with tangentially directed apertures F01N1/089using two or more expansion chambers in series F01N1/10in combination with sound-absorbing materials F01N1/12using spirally or helically shaped channels F01N1/125in combination with sound-absorbing materials F01N1/14by adding air to exhaust gases F01N1/16by using movable parts F01N1/161for adjusting resonance or dead chambers or passages to resonance or dead chambers F01N1/163by means of valves F01N1/165for adjusting flow area F01N1/166for changing gas flow path through the silencer or for adjusting the dimensions of a chamber or a pipe F01N1/168for controlling or modifying silencing characteristics only F01N1/18having rotary movement F01N1/20having oscillating or vibrating movement F01N1/22the parts being resilient walls F01N1/24by using sound-absorbing materials