The BPF R427 system is constructed using passive regeneration silicon carbide (SiC) filters where the regeneration is facilitated by a concentrated liquid catalyst (commonly called FBC - Fuel Borne Catalyst) that is mixed into the fuel. This system allows regeneration from temperatures as low as 340 - 350°C. The BPF R427 filter is approved according to the Swiss VERT off-road procedure and is included in the VERT FILTER LIST.
The BPF R187 system is constructed using silicon carbide (SiC) filters. The product is particularly simple and extremely effective, guaranteeing over 97% particulate filtration. The regeneration of the R187 filter is facilitated by an external electric regeneration unit.
The system BPF R620 is realized with the use of filters made of silicon carbide (SiC) associated with oxidation catalyst, placed in front of the filter to ensure the reduction of emissions of unburned hydrocarbons (HC) and carbon monoxide (CO). This combination allows to increase the value of nitrogen dioxide (NO2) that, unlike oxygen (O2), allows for the burning of the particulates at temperatures compatible with those present in the exhaust gas.
The system BPF R360 is realized with the use of filters made of silicon carbide (SiC) in which the catalytic activity oxidant is delegated to the deposition of noble material directly on the filter substrate to ensure also the reduction of emissions of unburned hydrocarbons (HC) and carbon monoxide (CO). This combination allows to increase the value of nitrogen dioxide (NO2) that, unlike oxygen (O2) allows for the burning of the particulates at temperatures compatible with those present in the exhaust gas.
Characteristics and operating principles of diesel PARTICULATE FILTERS
Bersy manufactures the BPF filters using silicon carbide as this is the optimal material in terms of thermal resistance, mechanical resistance and filtration efficiency.
Bersy can also supply, on request, cordierite filters; Cordierite is a ceramic porous material which is lighter but more delicate as compared to silicon carbide.
The ceramic substrate is manufactured as an extruded honeycomb structure and the channels are blocked at alternate ends, as shown in the image below. The exhaust gases are forced to flow through the walls between the channels, which are able to retain very fine unburnt carbon particles.
Regeneration, however, is not capable of completely removing all the solid particles and it cannot remove engine oil ashes. These ashes are trapped in the filter and to remove these further cleaning is required every 1000-1200 hours (depending on engine condition, maintenance, fuel quality, engine oil quality and other parameters). This cleaning consists of cooking the filter at high temperature and pulsing air through the channels to remove the ash; this procedure must be performed with special machines in order to preserve filtration efficiency and regeneration performances.
Bersy considers many factors when specifying diesel particulate filters, including the specific application, exhaust gas temperatures and the regeneration technology available.