Diesel Particulate Filters - What, How & Why?
All About Diesel Particulate Filters
What is a Diesel Particulate Filter?
A diesel particulate filter, or DPF for short, has a function similar to that of the catalytic convertor fitted to most petrol-engined cars. It is a device designed to remove diesel particulate matter or soot from the exhaust gas of a diesel engine. Wall-flow diesel particulate filters usually remove 85% or more of the soot, and can at times (heavily loaded condition) attain soot removal efficiencies of close to 100%. A diesel-powered vehicle equipped with a properly-functioning filter will emit no visible smoke from its exhaust pipe.
How Does it Work?
The DPF looks similar to a traditional exhaust silencer, but is mounted close to the engine. Inside is a complex honeycomb ceramic structure designed to filter the exhaust gases while minimising flow (which would otherwise limit performance). By forcing the exhaust gases through the walls between the channels of the DPF, the particulate matter is deposited on the walls, so reducing the amount of air pollution.
Why Does my Car Need One?
European Emissions legislation is becoming progressively more stringent with regard to the level of emissions which vehicles are permitted to give off. Diesel fuel when burnt gives off a range of exhaust gases including sooty particles, or particulates, often visible on older diesel vehicles as black exhaust smoke.
