· Operates from engine start-up
· Suitable for many different Diesel Powered Applications
· Silicon Carbide or Cordierite Filter
· Regenerates at 250/280°C
· Available with or without Catalyst Catalysts Many different catalysts are available in order to cause the Particulate matter to burn off at a lower temperature. In a Continuously Regenerating Trap - CRT system a Diesel Oxidation Catalyst DOC up stream of the DPF creates excess NO2 which acts as a catalyst to burn the soot at a lower temperature. This system is found on many HGV’s and Coaches and Buses. A catalyst can be added to the fuel, Fuel Bourn Catalyst, FBC systems. The additive then builds up in the soot in the filter and creates conditions that enable the soot to burn off at a lower temperature. The wall filter material can be coated in a catalyst – These are usually based on rare earth elements such as Platinum or Palladium. Applications Installation Maintenance Filter Life
· Up to 90% Reduction in PM
Diesel Particular filters are capable of reducing particulate matter (PM) from the exhaust of a diesel engine by up to 90% and effective from start-up, the DPF system is based on a Silicon Carbide or Cordierite filter, manufactured as an extruded honeycomb structure and able to retain very fine un-burnt carbon particles. The Channels are blocked at alternate ends, forcing the exhaust gasses to flow through the walls between the channels, known as ‘wall-flow’, the particulate matter cannot pass through the walls and is deposited within the channels.
As particulate matter is collected in the filter the carbon deposits are burnt away, this is known as ‘regeneration’. Failure to regenerate will cause the filter to block, which in turn can damage or destroy the filter itself or cause damage to the engine due to increased backpressure. In order for the continuous regeneration to take place the exhaust gas temperature must be at least 250/280°C and in the presence of a catalyst. Without a catalyst soot burns in air at around 600-650°C. Regeneration consists of burning the carbon particles collected in the filter.
Due to the high temperatures involved in regeneration, these filters are suited to high usage applications where the exhaust gas temperature is high, i.e. prime power generators, high usage materials handling equipment, construction equipment & non-road mobile machinery (NRMM). The DPF is also suitable for on road vehicles such as buses, coaches and HGVs
The DPF filter requires a high temperature to enable the regeneration to take place; therefore the best performance is achieved when the filter is positioned as close as possible to the engine. Insulating both the filter and connecting pipe work will increase the efficiency further. In many applications the filter can be fitted to the exhaust in place of the original silencer.
The filter does not require any general maintenance, however, due to varying operating conditions and engine maintenance, an annual inspection is recommended. Ash build up must also be removed by heat treatment every 2000 hours, for road vehicles this equates to annually, this involves the filter being removed from the exhaust and heat treated in a furnace to 600°C, whilst vacuuming the debris out.
