Catalytic Converter: Description and Operation

GF49.10-S-3006SA Component Description For Diesel Oxidation Catalytic Converter

ENGINES 642.8 in MODEL 906
- with CODE (MG5) Engine OM 642 DE 30 LA, 140 kW (190 hp) 3800 rpm
- except CODE (ZU7) National version for Canada
- except CODE (ZU8) National version for USA

ENGINES 642.8 in MODEL 639
- with CODE (XZ1)
- with CODE (MZ0) Blue EFFICIENCY

Illustrated on model 906






21 Muffler
114 Diesel particulate filter (DPF)
120/1 Oxidation catalytic converter

Location
The oxidation catalytic converter is a near-engine mounted version located downstream of the turbocharger.

Task
Oxidation of the following pollutant components:
- Carbon monoxide (CO)
- Hydrocarbon (HC)
- Nitrogen oxide (NOX)

Design






111/1 Stainless steel housing
111/3 Ceramic monolith
183 Incoming exhaust flow
184 Outgoing exhaust flow

Function
The exhaust flow entering the oxidation catalytic converter consists of the following components:
- Carbon monoxide (CO)
- Hydrocarbons (HC)
- Nitrogen oxides (NOX)

The exhaust flow exiting the oxidation catalytic converter primarily consists of the following components:
- Carbon dioxide (CO2)
- Water (H2O)
- Nitrogen dioxide (NO2) and nitrogen (N2)

Coated cell structure






111/3 Ceramic monolith
111/4 Intermediate layer (washcoat)
183 Incoming exhaust flow

The ceramic monolith is a ceramic body consisting of many thousands of small passages. The ceramic consists of a high temperature-resistant magnesium-aluminum silicate. The monolith, which reacts very sensitively to voltages, is mounted in a stainless steel housing.

The carrier layer with the active catalytic layer, attached to the ceramic monolith, contains platinum as the active component and accelerates the oxidation of HC, CO and NOX.

The amount of precious metals in an oxidation catalytic converter is between 2 and 10 grams depending on the size and design.