DPF - BERSY

Pollution in town and city centres is a growing problem and that is why partial or total limits are imposed on traffic. Cars, commercial vehicles and numerous public transport vehicles, often belonging to the old generation, are in fact considered the main sources of atmospheric pollution. Car manufacturers, as a result of increasingly more restrictive laws, have developed new and better systems to reduce the emission of pollutants. The latest of these is the DPF or particulate filter, designed to limit the emission of black fumes from diesel engines. Fitting only a catalyst exhaust in fact is not enough to ensure the reduction of particulate as catalysts are only effective on CO, HC and aldehydes. With the introduction of the DPF particulate filter, major results have been achieved as regards the reduction of fine particles. New diesel engine injection systems have also brought about a significant reduction in particulates, but thanks to the fitting of DPFs, pm10 emissions have been drastically cut. The DPF is a real and true filter able to trap the carbon particles contained in diesel engine exhausts. The DPF particulate filter, with its honeycomb structure, manages to trap the fine particles which remain imprisoned in the filter itself; thanks to DPF regeneration, the particulate is then burned, thereby stopping the filter from becoming blocked during operation. To allow DPF regeneration, the high temperature of the exhaust gases is required. When this high temperature is not reached, either pre-heaters or additives to be mixed in the fuel are used to allow the DPF to operate properly. These regeneration systems are by now automatic and generally controlled by an electronic control unit able to continuously monitor the operating condition of the DPF particulate filter. In some European countries, regulations have already become applicable whereby DPF filters also have to be fitted on worksite machinery and these are expected to be shortly extended to the rest of the European Community as well.