6 November 2006 -- The accurate monitoring and control of stocks of alcohol to levels of accuracy better than +/-2mm using radar gauges is proving a successful market for Enraf Limited. The trend towards radar for new installations is being driven by the low levels of maintenance that non-contacting gauges require and with greater quantities being sold they are now cost-competitive with servo gauges. Gauges can be used to record the level of spirit in a tank or vat and as part of the audit trail that records the intake or transfer of spirit to other vessels or sites.
Any errors can give considerable problems in reconciling spirit movements and could, if beyond C+E allowances, lead to severe financial penalties.
Caledonian Bottlers in Scotland are realising the benefits of Enraf radar gauges, having had a system designed and installed by specialist instrumentation and control systems company J.E Cockayne.
Here the essential requirement was for a non-contact level gauge that would enable Caledonian Bottlers to fill their vats to the maximum design height.
'An accurate level gauge can be employed to measure the initial quantity of the spirit in the vat and the data used to calculate the amount of water required for reduction', says Ian Cockayne: 'After reduction the level gauge is used to measure the bulk content of the vat'.
A further development that is encouraging the wider use of level gauges is the trend by some malt distilleries to load tankers with the spirit, for cask filling at another site.
In this scenario, the level gauge is used to control and monitor the quantity of spirit filled into the tanker.
'The solution that we devised in conjunction with Enraf for Caledonian Bottlers uses a SmartRadar FMCW system,' continues Ian Cockayne: 'This gives accuracy levels of up to +/-0.4mm over the complete working height of the tank.
The gauge level signal is used in conjunction with the vat calibration tables to display level and volume on a P1200 SCADA system.
With the SmartRadar Enraf has overcome the problem of measuring within the blocking distance, a problem associated with other radar gauges, by designing a range of antennae that allows installation on practically any storage tank.
Because some radar gauges have a blocking distance in the region of 300mm to 500mm below the antenna and most spirit tanks are less than 4m high, a loss of 500mm is a considerable capacity deficit.
In a tank farm with 8 tanks, this equates to a capacity loss of one tank.
However, the Enraf planar antenna allows a low profile installation, which means that the full tank capacity can be used'.
Commenting on the new system, the plant manager for Caledonian Bottlers, Robert Brown says: 'The requirement of the gauging system was to match the compliance with HM Customs and Excise, while at the same time providing accurate data of alcohol usage.
Enraf and JE Cockayne worked with us from the outset, designing a system that met this challenge and giving us the peace of mind that we were dealing with a team which had more than two decades of experience within this industry.'
