The Aluminium Sulphates production facility at the Widnes site was some 40 years old and had reached the end of its working life. A new production facility was to be designed and constructed separate from the existing plant to minimise disruption of production. The control and operational philosophy would differ considerably from that of the existing plant, incorporating latest design techniques and hardware platforms.
Simonswood Automation provided the solution, based upon the Siemens S7-300 PLC system as the core process controller, with WinCC as the recipe handling and operator interface. The control system has a central processor S7-317 2DP with four remote ET200 distributed I/O panels, linked to the central PLC via Profibus, one of which has a fibre-optic link. The Profibus network also links five Micromaster Inverter Drives to the central PLC, whilst the WinCC communicates via Industrial Ethernet. The system controls two Reactors, Dilution Tank, Final Filtration and Storage Tank Control, together with raw material handling and services. In total the control system interfaces to 19 Motors, 43 Valves, 3 Weighers, 5 Flow Meters, 3 Mass Flow Meters, 3 Temperature Transmitters and 9 Level Transmitters.
The control software incorporates some 30 process calculations and formulas in order to achieve consistent raw material mass integration for the batching process, dilution and filtration of the product. All the control devices, instrumentation and process routines are verified throughout the production cycles for correct operation, including the continuous determination of the composition of each reactor contents.
“Simonswood Automation have developed a control system that has met and exceeded all of our expectations, they interpreted all of our requirements correctly, even providing additional features and innovations. We now have a production facility which is user friendly, reliable, stable and efficient, with their honest and ‘no fuss’ approach to business, the staff at Simonswood Automation have been an absolute pleasure to work with.”
Annette Halliwell – Production Manager