Exhaust gas circuit

It is basically made up of two impellers (1) fitted on one shaft (2), which rotates on floating bearings lubricated via a duct (3) from the engine lubrication circuit.

The oil used discharges part of the large amount of heat given off by the exhaust gases at the turbine.

There is a waste-gate valve (4), operated by a pneumatic actuator (5), on the turbocharger, which shutters the flow of exhaust gases to the turbine, according to the engine power/torque request.

1. Impellers
2. Shaft
3. Lubrication
4. Waste-gate valve
5. Actuator

EXHAUST GAS CIRCUIT

The engine exhaust gases flow through the manifold To the turbocharger and, through a pipe, to the oxidizing catalytic converter and then to the silencer.

Special protection limits the heat given off towards the bodyshell.

EMISSION CONTROL DEVICES

CATALYTIC CONVERTER

The catalytic converter is a post-treatment device for oxidizing the CO, HC and particle matter, transforming them into carbon dioxide (CO2) and water vapour (H2O).

The catalyst consists of a ceramic honeycomb structure (1), whose cells are impregnated with platinum (2), which acts as a catalyst for the oxidation reactions.

The exhaust gases which pass through the cells heat the catalyst, triggering off the conversion of the pollutants into inert compounds.

The chemical reaction of the oxidation of the CO, HC and particle matter is effective at temperatures of between 200 °C and 350 °C.

Above 350 °C, the sulphur contained in the diesel fuel starts to oxidize, producing sulphur dioxide and sulphur trioxide.