BPF Particulate Filter
The function of a diesel PARTICULATE FILTER
A diesel particulate filter (DPF) is used with diesel engines in order to reduce particulate matter from the exhaust gases.
They are manufactured from porous ceramic substrates which trap the particles in the exhaust flow. DPFs are capable of reducing particulate mass by over 99%.
The BPF filter for marine application is manufactured entirely in AISI 304 Stainless Steel and supplied together with a security by-pass valve and removable insulation.
Characteristics and operating principles
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.
The particulate matter trapped inside the filter channels must be burnt in order to allow the exhaust gases to flow correctly through the wall of the filter.
Particulate combustion (regeneration) happens under normal conditions at a temperature of 650 °C, which is not achievable unassisted in the exhaust gases of a normal diesel engine. Bersy offers various regeneration methods which allow the particulate combustion starting from 350°C.
During regeneration not only does the temperature inside the filter increase, but the backpressure decreases.
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.
It is recommended to read each DPF product sheet carefully and to consult with Bersy in order to specify the correct system for your application.
Bersy considers many factors when specifying diesel particulate filters, including the specific application, exhaust gas temperatures and the regeneration technology available.