filter technology in shipsShip building, engine technology and marine technology – these three broad topics give the SMM trade fair in Hamburg its name. Some two thousand exhibitors from around the world will be presenting their latest developments and innovations for the international shipbuilding industry in the city from 9–12 September 2014.

We at MANN+HUMMEL will also be on board in hall A4, at stand 111. I am particularly pleased that we will be presenting our new fuel prefilters from the PreLine 1201 series. These separate water and contamination from diesel fuels in an extremely efficient manner. Our filters are primarily used in four-stroke marine engines as typically used in river-, sea- and ocean-going ships up to 100 metres in length.

I have been working with fuel filters at MANN+HUMMEL for more than ten years. My first project in the maritime field was a double filter head made from spheroidal graphite iron, which has mechanical properties similar to steel. With a switch device – consisting of two connected ball valves – it is possible to switch from one filter element to another. This allows a contaminated filter element to be replaced without having to interrupt engine operation. The current PreLine filter system 1201 is based on this original design concept.

I have been in close contact with Germanischer Lloyd all these years, a classification society for acceptance testing in the shipbuilding industry. Fuel filters for ships are subject to very specific requirements. Attention must be paid to the melting temperature of materials and their elongation properties. Depending on the material used in filter housings and components, 30-minute flammability tests need to be carried out, filter changes must not result in any leaks, extensive vibration and pulsation tests are necessary, requirements for burst pressure must be observed, and much more.

Schiffbau auf der SMMWe have implemented many innovations in all of these fields. The insulation of our liquid level sensor, which can detect water that has separated from fuel, is one example.

This liquid level sensor is mounted on the filter element and uses two electrodes to report when half a litre of water has separated and needs to be drained by the mechanic. I had to deal with these seemingly basic components in depth during the development stages. No wonder the liquid level sensor with polyamide housing proverbially ‘went up in smoke’ during flame testing and basic protective measures did not present a working solution.

Next, I experimented with fire-resistant, mineral ramming mixes as a material, in the way that they are also used in furnaces, for example. While this did make the sensor fire-resistant, it was far too heavy and sensitive to vibrations. The development team made contact with a company in Cologne that manufactured materials for controlling fires. Together we developed a suitable light material that does not cause any weight problems, expands in the event of fire and thereby forms a fire-resistant protective layer. At the same time, I developed another type of sensor with an insulated protective cap around the sensor.

We received type approval (component release) from Germanischer Lloyd in November 2013 for both designs, which allowed us to use our PreLine 1201 fuel prefilter on ships with SOLAS requirements. SOLAS is a UN Convention on ship safety.

Verbrennung im Schiffbau

And the development continues. New engines with new injection systems require filters that can withstand even greater pressure. Pressure resistance up to 20 bar in accordance with the SOLAS guideline is our next development goal … and I already have an idea how it will work!