Processing Pure and
Processing Pure and Affordable Drinking Water for a Whole Region Sliding gate valves are optimizing Belgium’s largest facility for RO water purification Veolia Water Technologies has built an ultra-modern plant to produce drinking water in Ostend, Belgium. In a multi-stage filtration process, the local water supplier is now producing drinking water of excellent quality – far above the statutory requirements. At critical points of the process – during reverse osmosis, filtration with activated carbon and remineralization of the water – sliding gate valves made by Schubert & Salzer Control Systems are responsible for regulating pressure and flow rate. The water supplier, FARYS, produces drinking water for the city of Ostend and its surrounding area from the brackish water in the Bruges-Ostend Canal. In the current development stage of the waterworks built by Veolia Water Technologies, up to 1,200 cubic meters of drinking water per hour can be fed directly into the pipe network. The plant constructed by the leading specialist for water treatment is the largest Belgian drinking water production facility using RO technology and the production speed is among the fastest in the world. It is also unique that the installation can be used very flexibly within a variety of canal water qualities and that the entire process is done within considerably reduced energy costs. One DN 125 and one DN50 sliding gate valve are used in each of the twelve reverse osmosis units. Frederik Debaillie, project manager of Veolia Water Technologies Belgium, describes the process as follows: “The canal water is treated in eight stages. First, in coarse, fine and microfiltration, all suspended particles, microbiological substances and pathogenic microorganisms are removed. During the subsequent reverse osmosis, finepored, semipermeable membranes filter microcontaminants up to particle sizes of 0.1 nanometer as well as minerals and salts.” Only water molecules remain. This water is sent through activated carbon filters and after injection with carbon dioxide, remineralized with limestone. Finally the water is disinfected with UV light and then chlorinated. The result – drinking water of the highest quality – is fed into the pipe network via buffer storage tanks. “The operator of the waterworks wanted a facility that works cost-effectively. Maximum energy efficiency was required everywhere – even at the control valves”, explains Tristan Lejeune, International Sales Manager at Schubert & Salzer Control Systems. “Equally, reverse osmosis and the subsequent process stages are demanding applications. There are special requirements here in terms of the control accuracy and reaction speed of the valves used.” Sliding gate valves provide effective protection against damage “During the reverse osmosis process, precise and fast pressure regulation is very important”, emphasizes Debaillie, The precise flow control of the sliding gate valves ensures that each of the eight activated carbon filters (pictured here) and 13 remineralization tanks are evenly utilized. the Veolia engineer. “The highly sensitive filtration layers are rolled up in pressure pipes. Pressure shocks and excessive flow quantities have to be reliably prevented. Even the slightest overshoots in the control process could damage the expensive membranes. That is why we use one DN 125 and one DN50 sliding gate valve produced by Schubert & Salzer Control Systems in each of the twelve reverse osmosis units. They ensure the exact regulation of the high process pressures that are necessary to compensate for the osmotic pressure of the brackish water and keep the reverse osmosis going. 22
We bring colour into view! Compact pressure sensors and switches with 360° custom-colour status display Processing 256 colours Individually selectable: Measurement in progress Sensor switching Process malfunction Compact design 15 cm Hygienic adapter system Adjustment via smartphone DRINKTEC: Hall A3, stand 230 www.vega.com/vegabar drinkworld Technology + Marketing · September 2022 23
