The efficiency of nature

Just a few hundred metres from the North Sea, Dunea Duin & Water at Scheveningen is located within an oasis of dunes and grasses in an otherwise densely populated area of The Netherlands. These dunes are not just beautiful, they have been acting as a natural water filter for decades. When water is pumped from a tributary of the Maas River to several dune ponds it slowly sinks into the dune sand and stays there for around two months, leaving it filtered of bacteria and viruses. It is a unique and natural purification process that other water facilities, less blessed with such natural resources, would need chemicals to achieve the same purification process.

It is this natural, efficient working method that seems to underpin the operational philosophy at Dunea: robust, smart, efficient and reliable. One of the electrical engineers at Dunea, Cees van de Noort, forms part of a dedicated process automation team responsible for the constant supply of fresh drinking water to over 1.3 million people throughout
The Hague city and surrounds. Electrical engineering has been a central focus of Cees’ professional life since graduating from high school in Leiden – and he has since built up decades of hands-on experience gained working in various facilities from water plants in Sumatra to petrochemical plants in Europe – all the while installing hardware and electrical systems to enhance profitability and reliability. This has led to his specialisation, and passion, for PROFIBUS systems – a particular technology utilised by Dunea Duin & Water to enhance their operational efficiency.

Increasing demand

As population levels in the area have increased, so to has the level of water usage. “On any given workday at 6am we will be supplying drinking water at a rate of 214,000 litres per minute, just an hour later it will have doubled” says Cees. However, demand can be unpredictable, as evidenced by water usage caused by flushing toilets during half-time of a World Cup football match. The task will also become more complicated over time, says Cees. “For example our readings show an increased usage of Ibuprofen in society, these trace amounts of pharmaceuticals are steadily increasing and will require advanced oxidation to remove them from the water chain – it won’t go away by itself.”

Dunea Duin and Water - Pump room

Fieldbus systems – PROFIBUS

Today, PROFIBUS is the dominant player in factory and process automation with a large installed user base, counting 50.9 million devices installed by the end of 2014 with over 9 million of these in the process industries. So why is Dunea using PROFIBUS? Cees explains, “PROFIBUS allows us to work with slave addresses with no interference from the outside world (Profi-Net) or other masters and devices. It is easy to monitor with Profi-trace or Combricks. Further, PROFIBUS doesn’t require IP addresses, hence no need for costly firewalls and the cyber security is tighter.” Cees shows us the operations room, where in-house built software displays all flow and pressure readings and provides notifications on failures, calcium levels, flow volumes, depths of filtration ponds and water extraction levels. Ground water that is pumped out of the water chain needs to be replenished, and all is closely monitored.

“The great thing about PROFIBUS is that it supplies us with an internal operable network. It uses a single central line (two wires) that connects automation and control systems with distributed field devices such as actuators and sensors. At this facility in Scheveningen alone we have 1200 valves, more than 150 actuators and more than 300 sensors. The line allows for transmission of automation messages, along with other features including device self-diagnosis. It also supports acyclic and cyclic data exchanges, isochronous messaging and alarm handling”.

As we walk into one of their pump rooms and I notice a lot of actuators from one particular supplier. Asked whether Dunea prefer one brand over another, he adds, “We use a variety of suppliers, just to keep them on their toes” he grins. “You might see one actuator brand indoors; outside it might be another altogether”. One thing about PROFIBUS is that it enjoys broad vendor support, with over 24 million nodes, it has possibly as many as all its competitors put together. “A lot of suppliers have developed PROFIBUS enabled devices so there is a lot of choice out there. It’s good to have a wide range of suppliers to choose from, which of course ensures that price is kept under control”.

Dunea Duin and Water - Control room

Tips for others

Dunea decided to take on advice for their PROFIBUS installation, with some guidance from third party PROCENTEC. Cees has some tips for others looking to do the same: “If anyone else was considering a PROFIBUS installation I’d advise them of a few things. For example don’t allow your PROFIBUS cables to run in parallel with low- or high voltage cables. The magnetic fields from these cables can tend to cause interference and static. Secondly, it’s a good idea to house your PROFIBUS cables in steel guttering, to further protect them against interference from magnetic fields. Protect your cables from any other energy sources. The costs of troubleshooting problems such as unexpected static can mount up over time and be sure to use certified equipment or machinery, this prevents a lot of trouble shooting and communication errors”.

Monitoring a facility can also involve a lot of legwork, Cees here has a solution for this: “Use plugs with an integrated extra connection to hook up your laptop. This will significantly reduce the time spent walking. Also consider connecting a Profi trace, but do make sure you can match the Profi trace anywhere in the installation with the segment that you want to monitor.”

Oxygenation of water takes place under blue light.

The benefits of certification

Cees is quick to stress the importance of third party certification. “We would always advise a facility to get their installation certified by a third party. We work closely with PROCENTC who take care of all our certifications. All too often it’s the system that gets the blame. Our experience is that a certified and high quality PROFIBUS installation pays dividends. Be specific about your standards and expectations and stick to them. Don’t compromise.”

“Our last upgrade was the installation in the decalcification process. Here we have 8 masters in combination with four controllers, and here we’ve opted to use PROFIBUS for as many components as possible. By specifying high standards at the specification stage we’re now seeing very few issues in the PROFIBUS installed environment.”

“PROFIBUS supports better diagnostics, which means commissioning can happen a lot quicker. It just gives us better quality data that is timelier and essential for operations and management. what makes PROFIBUS so attractive is its ability to drive down our overheads and improve operational efficiency throughout the lifetime of the facility – this includes the whole lifecycle from design, ongoing maintenance and revamps as well.”

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