Nestlé is one of the world's largest food companies and Nestlé Waters is the world's largest bottled water company. Bottled water is one of the fastest growing sectors of the beverage industry, estimated to be doubling every 3-4 years. In South Africa, Nestlé Waters became one of the major players in the bottled water business through its Valvita and Schoonspruit brands. One of Nestlé Waters' most important assets is the Doornkloof plant near Olifantsfontein where the aquifer in the underlying dolomite produces one of the finest natural mineral waters in the world. When the plant burnt down in October 2002, management sought an urgent replacement for this strategic resource.
After rigorous auditing procedures to comply with Nestlé's corporate procedures, a proposal from a partnership comprising of Solutions Technology, Schneider Electric and Ram-Tec Systems was accepted. This consortium would be responsible for implementing the process, electrical and automation solutions on a turnkey basis.
Solutions Technology provided process project management expertise and produced the P&ID drawings required for the new plant. Ram-Tec Systems was awarded the job of doing the power reticulation and energy management, plant automation and management information systems (MIS).
When it came to the control system, Ram-Tec chose Wonderware's InTouch scada solution that provides plant visualisation and operator control. Special diagnostic screens where developed to allow plant maintenance personnel to fault-find the networks from the scada system easily and intuitively.
The addition of the flavouring powders and sugars are done using the batch facility of InTouch while Wonderware's IndustrialSQL Historian was installed to store and provide process traceability and production information. Wonderware's Active Factory was installed on the PCs of plant managers to give them realtime access to production and process status information.
InTouch, together with the latest fieldbus technology, was also used as a diagnostic tool to simplify maintenance and commissioning while reducing downtime. "The graphical representation of fieldbus installations and system diagnostics can convert complicated information into an easy-to-understand format," says Darryl Opie of Ram-Tec Systems. "The bus systems used were Profibus DP, Profibus PA and ASI but the approach applies to most industrial bus systems."
In the Nestlé Waters implementation, InTouch is used to display the diagnostic information available from modern fieldbusses for the graphical representation and maintenance of networks and can indicate if it is plant equipment, instrumentation, communication cards, remote I/Os or even PLC configurations that are causing the problem. On certain networks, it is possible to indicate where a cable has been damaged and if instrument faults are detected, this information can be used for process interlocking.
"The display of bus information shown on the HMI's screen has made such a difference that, today, I will not commission a site without having all the network diagnostic information displayed on the scada system," says Opie. "Industrial busses are so much more than the interconnection between devices. They hold a wealth of diagnostic and status information, so why not use it and, in this case, InTouch was the ideal reporting agent."
The coming on-stream of the new facility has coincided with the launch of Nestlé Waters' new flagship brand, Nestlé Pure Life. Although new to South Africa, the brand already exists in 16 countries around the world, since its initial launch in 1998. The technologies and systems implemented in the new plant have substantially increased productivity. Whereas the previous plant had to work 24/7 just to supply demand, the new facility has almost quadrupled that capacity.
The water purification process
The control process starts when water is pumped from the aquifer. Once the water is exposed to air and surface temperatures, it becomes prone to bacterial infestation. To prevent this, the water is first exposed to ultra-violet (UV) light. It then passes through high-grade filters to remove any suspended solids.
After this, the water is once again exposed to UV light for further purification. The differential pressure across the filters is monitored to check whether they are becoming clogged. Before the water can be bottled, it has to conform to strict hygiene requirements that involve a technique known as 'cleaning-in-place' (CIP). Essentially, this involves raising the temperature in pipes and vessels to that required to kill pathogens.
CIP is required between changes from unflavoured to flavoured water and between flavour changes. The water needs to be heated before the plant starts operating in the mornings and so the boilers are started at 4 am to be ready for production every day.
For more information contact Darryl Opie, Ram-Tec Systems, 011 616 1328, [email protected], www.ramtec.co.za or Futuristix, 011 723 9900, [email protected]
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