Johnny Walker, the world's leading Scotch whisky, is bottled at United Distillers packaging site at Kilmarnock in Ayrshire, Scotland. Following a recent upgrade project undertaken by Scomagg Ltd from their Motherwell Head Quarter the site is now using PROFIBUS communications to help control its Bulk Filtration plant. In this plant, blended whisky is transported via pipeline from the bulk blending facility into one of 11 Reducing and Colouring Vats. There it is chilled, filtered and heated, then diverted into one of 11 Bright whisky vats. Finally, it is transferred to one of 40 bottling vats located up to 500 metres away.
Conventional I/O includes 18 temperature sensors, 18 temperature control valves, 6 pressure switches, 7 flowmeters, 7 flow control valves and 1 pulse counter. The PROFIBUS network encompasses a total of 62 vats, including 292 control valves, 19 level gauges, 102 level switches, 4 pressure switches, 6 SIL, 15 MCC I/F (start and running), 22 push buttons and 44 lamps. The total area covered is approximately 1km and data rates of 500 kB/s are used. In all there are 74 nodes in 5 PROFIBUS segments encompassing 900 inputs and 500 outputs.
The advantages of using PROFIBUS included lower ownership costs, wide area coverage, the fact that it could be installed and commissioned before plant shut down and that it allowed interfacing to valve stations; valve manifolds were being replaced as part of the project anyway, so this proved to be an effective option.
The solution also provided significant space saving as it was decided to make PROFIBUS the collection point for all digital I/O in the filtration area. Another important advantage of PROFIBUS was that there was only a limited amount of space in the main PLC room and by reducing the number of conventional termination panels, enough space was saved to get the new system in before the old system was removed.