Control system for Imerys
Production facilities include pits, refiners and dryers, each having substantial wet-storage capacity. These are interconnected by a vast underground network of pipes, allowing slurry suspensions to be moved from one plant to another. The largest refinery at Goverseth contains five main plant areas, and Mike Ford needed to link all sections to one local control room. He surveyed all the available fieldbus technologies and chose Profibus DP and PA for a variety of reasons, the most significant being the cost saving on wiring arrangements and the availability of all components needed for the proposed automation — PLC, HMI, remote I/O, valves and prime sensors etc.
Endress + Hauser, who offer a full range of Profibus PA measuring devices, were asked to supply the following measuring techniques: ultrasonic level, pressure, differential pressure, electromagnetic flow, mass flow, hydrostatic level, turbidity and microwave, together with Commuwin II maintenance software. Mike commented: ‘By connecting my laptop to the Profibus network I was able to access all measuring points remotely and commission a 1km section of plant comfortably and quickly, within half an hour.’ He added: ‘The automation has provided a number of significant advantages which include improved production efficiency, additional environmental monitoring and plant status, and improved operator well-being and comfort through reduced visits to remote process areas.’
Imerys need to monitor the stock density of the kaolin suspensions to determine the quantity of material in the water. Endress + Hauser Deltapilot 53s (rope mounted) are suspended in the tanks to measure the head pressure while Promass T ultrasonic level transmitters measure the overall level. These measurements are then used by the PLCs to calculate kaolin stocks.
Extensive training was provided by Endress + Hauser for all relevant personnel.
