Gas purification system through a filter system, especially applicable to internal combustion engines

Claim 1

Gas purification system though a filter system, especially applicable to an internal combustion engine, comprising: engine exhaust ducting connected to the engine; an exhaust pipe connected to the exhaust ducting; an expander on the exhaust pipe located between the exhaust ducting and a muffler; a duct, connected to the expander, for diverting escape gases from the exhaust pipe; an automatically operated pressure reducer, located on the duct, which sucks from 60 to 90% of the escape gases given off while the engine is running in neutral; a series of filtering parts, serially interconnected on the duct between the expander and the pressure reducer, for purifying the escape gases that are sucked by the pressure reducer; a regulator, located between the pressure reducer and the filtering parts, that mixes the filtered gases in adequate proportions with air and returns the mixture to an engine inlet duct; a relay, connected to the pressure reducers, for starting or stopping the operation of the pressure reducer; a contactor, connected to the engine, for detecting changes in engine speed; an electronic circuit, connected between the contactor and the relay, for signaling the relay when the contactor detects that the engine is idling or is beginning to accelerate; and a delay switch, connected between the relay and the electronic circuit, that momentarily delays the shutoff signal from the electronic circuit to the relay when the engine begins to accelerate out of idle.