The increasing demands for fuel filters used to provide clean fuel to state-of-the-art common rail injection systems require the use of highly efficient filter media. The lifetime of a fuel filter is - besides the particle separation efficiency - a key feature for a “fit for use” design. With rising restrictions regarding the construction space and stringent weight limits, the systems need to get smaller while increasing the dust holding capacity.
To reach high service intervals and provide outstanding fuel cleanliness, a combination of different filter stages is an alternative to one single, high efficient filter cartridge. When balancing the size and increasing the efficiency by each stage, ultra-high filtration efficiencies can be realized by keeping a compact design.
For a field relevant development the boundary conditions for each stage need to be considered. A pre-filter is usually operated on the suction side of the low pressure fuel pump while the main filter is located on the pressure side. Therefore the final differential pressures of these stage are significantly different. The pre-filter is therefore optimized to not exceed e.g. 300 mbar differential pressure at end of life but the main filter is designed to make use of an allowed pressure level of e.g. 2 bar after the same mileage. It is possible to integrate multiple filter layers or stages within either the pre- and/or main filter. With the gradient structure of these stages, the overall size of the filter system can be reduced.
The presentation highlights the possibilities for improving dust holding capacity when using multiple stages and shows the influence of different test dusts on the filter concept....
Session: L7 - Depth Filtration – Applications
Day: 14 March 2018
Time: 10:45 - 12:00 h