Rotork electric valve actuators are to be used at two environmental projects in The Netherlands. In the first, the actuators incorporate Foundation Fieldbus connectivity with a Fisher Delta V DCS (distributed control system) for the supervision of a district heating scheme in the Westpoort area of Amsterdam. Designed by the utility company Nuon, the scheme provides “clean” heat using steam produced from a municipal rubbish incinerator that would otherwise be wasted. The incinerator provides steam to run generators that supply electricity to the local grid. Rotork has supplied IQ actuators with factory fitted Foundation Fieldbus cards to operate Adams butterfly valves on the scheme.
A short distance away, Rotork IQ actuators with Profibus connectivity are employed at a pollution clean-up project in the Ketelmeer, a lake at the mouth of the River IJssel. The river carries particles of silt, sand and clay that settle on the Ketelmeer floor. This sediment contains waste material from factories along the IJssel and the Rhine which over time has built up into a thick layer of contaminated sludge. To store the sludge, a huge clay-lined pit, or depot, surrounded by a 10-metre high dyke, was built in the middle of the Ketelmeer itself. Once the entire Ketelmeer has been cleaned up, the filled depot will be permanently sealed with layers of clay and sand and converted for recreation and nature reserves. The scheme involves diverse pumping and pipework plant, valves, flow meters and instrumentation to dredge the polluted silt from an area equal to the size of nearly 6000 football pitches. In addition, 7 million cubic metres of silt from other areas is being shipped in for treatment and storage. This silt is transported to the depot through more centrally controlled pipework. The entire operation is controlled from a centralised control room within the new administration facility built on the IJsseloog Island beside the depot. A Profibus two-wire network provides control and monitoring communication between the DCS and field equipment, including the Rotork actuators, which control the movement of the water and silt throughout all the transporting and processing stages.
