SCADA solution adapts well to change

A grain drying and storage facility that supplies some of Scotland's leading distilleries has installed a new supervisory control and data acquisition (SCADA) system to consolidate its regular plant upgrades and expansions, to provide control and visualisation for product movement, processing and storage, including the integration of biomass boilers and heat recovery systems.

Highland Grains is an agricultural cooperative – owned by its 89 members – which dries, conditions and stores malting barley and other crops. It primarily supplies the Scotch whisky distilling industry, but also exports grain to other countries.

Based just north of Inverness, Highland Grains was founded in 1978 with a capacity to handle 4,400 tonnes of barley a year. Steady expansion over the years since it was founded in 1978 has seen annual capacity grow from its original ability to handle 4,400 tonnes of barley every year to over 40,000 tonnes today. 

The plant consists of five continuous flow dryers, seven wet and 15 dry storage silos (ranging from 250 tonnes to 2,300 tonnes) and two warehouse-like flat stores of 7,500 tonnes each. The site also includes a heat recovery system on its drying systems, power synchronisation and biomass boilers.

The facilities have always been automated, and the control system and software needed to be frequently expanded to meet new requirements and accommodate new equipment. The control system has been maintained and developed over many years by Coldcurve, which most recently was commissioned to replace the existing much-extended control system with an efficient state of the art solution.

The project was lead by Coldcurve engineer, Daniel Castle, who explains that although operations at the site are relatively complicated, a simple system architecture was achieved: "Lorries are constantly delivering grain from the growers, while others collect dried malting barley for the distilleries,” he said. “It’s a 24/7 process at busy times, plus there are several different drying processes. There are also a number of subsidiary processes to control, such as incoming and outgoing weighbridges, boiler operations and heat recovery for energy efficiency."

The whole site is now controlled from a single, powerful PLC supporting 29 separate I/O cards. There are also two PCs and a number of touchscreen HMI's on the system, providing main and secondary control stations.

"The system now runs Movicon SCADA software, supplied by Products4Automation," said Castle. "We have used this successfully in many food and beverage applications."

The SCADA software provides constant real-time production process information, collecting data from multiple sensors on the plant and processing it into high level information. This allows Highland Grains to efficiently manage its plant and processes to meet customers changing needs.

Movicon is based on an XML technology that offers an all-in-one development environment for managing all HMI, SCADA and statistical production data analysis applications. This made it possible to minimise project development times and to create an open solution that is easy to maintain and flexible enough to accommodate future developments.

Movicon also supports web services, scalable vector graphics, OPC, SQL, ODBC, and other functions that enable integrated information and control systems to be developed, whether they be large or small.

"Flexibility is one of the major needs in modern automation,” said Paul Hurst of Products4Automation Plant. “Operators are increasingly insisting that their control systems have the ability to easily adapt to new demands."

It is important to consider whether their control solution is able to satisfy all automation application needs – from field control level right through to SCADA/MES and enterprise management levels to protect investments. "Movicon is a real-time flexible platform with high levels of connectivity, capable of adapting to all modern automation application typologies, so is the only software needed in the system," said Hurst.

Highland Grains has been successful over nearly 40 years due to a willingness to adapt to new and changing demands. With the Scotch whisky industry seeing a resurgence, (it is worth about £5bn to the UK economy and growing at 5% a year according to the Scotch Whisky Association), the company is expecting to further develop its site and facilities in the coming years. The simplicity of its control architecture and flexibility of the Movicon software will make this a straightforward task.