Emission Control Systems: Description and Operation

The emission control system is used to reduce harmful gases (CO,HC and NOx), produced by the internal combustion engine. The emission control system has the following three major sub-systems:

1. CRANKCASE EMISSION CONTROL SYSTEM

The crankcase emission control system is a closed-type crankcase ventilation system that prevents blow-by gasses from escaping into the atmosphere. The blow-by gasses in the crankcase are routed back to the intake manifold for combustion.

2. EVAPORATIVE CONTROL SYSTEM

The evaporative control system prevents the escape of fuel vapors from the fuel tank and carburetor into the atmosphere. It consists of various components which collect, filter and route the fuel vapors to the intake manifold for combustion.

3. EXHAUST EMISSION CONTROL SYSTEM

The exhaust emission control system consists of a catalytic converter, exhaust gas recirculation and air-injection or pulse-air system.