Delta Life 9

DELTARES, APRIL 2018 An alliance between Deltares and the corporate sector produces innovative techniques and creates new market opportunities for business. IMAGE ADOBESTOCK Anyone who has a mixer tap at home will be familiar with the clunk when they turn off the water: water hammer. In large systems, the associated pressure can rise rapidly or actually drop off. Deltares developed a model and software for AkzoNobel Industrial Chemicals to describe the consequences.  PRESSURE TRAVELS AT A THOUSAND METRES PER SECOND I n Twente in the east of the Netherlands, salt has been ex­ tracted for almost a hundred years by pumping water into underground salt domes. In the domes, which are about five hun­ dredmetres deep, the salt dissolves and brine is formed. If you allow the brine to evaporate, salt forms again. The systemwith approximately eighty active wells around Hengelo has grown organically over the years. AkzoNobel wants to be sure that the systemworks well and meets today's high standards be­ fore cleaning up and replacing the pipes. This was an interesting challenge for consultant and hydraulics researcher Kees Kooij. 'We already know a lot about how liquids be­ have in pressure pipelines but this complex brine system was a chal­ lenge for our software. The pres­ sure difference between the water with and without salt is large. If the pump system suddenly fails and the valves close, pressure waves are created that travel a thousand metres per second.' Peak pressure Ronald Kiewiet of AkzoNobel: 'The study conducted by Deltares has generated additional insights into the peak pressures in the system and the circumstances in which they can occur. It also turned out that a vacuum can be created when the valves are closed too quickly, and we don't want that either.' The results of the analysis were used to alter the design. Some valves, for example, no longer close automatically. The results are also used to give operators exact guide­ lines for how fast they can close the valves. For more information: k ees.kooij@deltares.nl KNOWLEDGE IN OPERATION