Food Engineering

Using fieldbus for filtration

March 30, 2003


New filtration lines at the Carlton and United Breweries plant in Melbourne, Australia, feature a new control system that allows users to plug together equipment from different suppliers to best meet their needs.


Although it appears relatively straightforward, the making of beer -- or at least consistently good beer -- has evolved into complex science requiring tight process control. So when Carlton and United Breweries (CUB), Australia's leading beer brewer, began to encounter greater market demand for specialty brands -- and greater competition from specialty brewers -- the company embarked on a $17 million plan to replace the filtration room of its Abbotsford Brewery in Melbourne, including the control system. "We just couldn't manage the number of brands we were being asked to make," recalled Abbotsford plant manager Matthew Anderson, noting that CUB's eight packaging lines often run 24 hours a day, seven days a week.

In all, more than 500 people work at the 22-acre plant during peak periods. If that seems like a small army, consider that CUB produces more than half the beer consumed in Australia. The company is also one of the top five brewers in the world, producing more than 50 different brands, including Foster's Lager, Carlton Cold and Crown Lager. In order to keep up with demand without sacrificing quality, "We had to increase our plant flexibility from a technological point of view, and we had to make our people more efficient and flexible," Anderson said.

In January, CUB installed the first of three new filtration lines, including a Swiss-made diatomaceous earth filtration system that converts cloudy fermented beer into a sparkling clear product. The new control system centers on Fisher-Rosemount's Plantweb architecture, including the DeltaV scalable automation system, digital valve controllers, pressure, temperature, conductivity and flow measurement instrumentation.

CUB project manager Ray Glastonbury noted that the Delta V system employs digital fieldbus technology -- essentially an all-digital, two-way communications system that interconnects measurement and control equipment -- that adheres to the stringent codes of the Fieldbus Foundation. Comprised of more than 100 member companies in the process automation industry that have set standards for interoperability, multidrop wiring, device-based controls and other functions, the foundation is dedicated to creating a network standard that allows process automation users to plug together equipment from different suppliers to best meet their needs. As a result, "users aren't locked into proprietary networks or stuck with regional standards," Glastonbury said.

As part of CUB's National Technology Group, Glastonbury had been watching digital fieldbus develop as a technology for some time and knew the new filtration room provided an opportunity to test it. "Because we've traditionally used Allen Bradley equipment, the interoperability of the network and the open architecture of the DeltaV were important features that allowed the systems from two different manufacturers to communicate," he said. "We're running about 30 process loops with a number of different devices. We felt this system gave us the most promising upgrade path for the future."

Advanced features

Currently, CUB is primarily using the DeltaV for gathering data on temperatures, conductivities, pressures, flow rates, densities, oxygen and carbon dioxide levels. However, once the dust settles on the filtration room project, CUB plans to utilize some of the systems more advanced features. Its "built for batch" flexibility, for example, enables CUB to alter its production and adapt to specific market demands with the flick of a switch. And its advanced diagnostics and Asset Management enable the company to pinpoint problems as they occur in production, without shutdown and maintenance.

"We'll probably be very conventional in our overall data gathering," Glastonbury said. "The PID control algorithms are all sitting on the programmable logic controller. We transfer data into the PLC, manipulate it, and send it back to the control loops. It's fast and easy. With the old system we'd bring raw data back to the operators and often they couldn't make much sense of it."

Now, he said, operators know what's going on in the plant and can respond immediately. Just as importantly, they can pinpoint problems as they occur at the device level rather than shutting down the whole line.

Fisher-Rosemount Systems, Inc., 8301 Cameron Rd., Austin, Tx. 78754. Tel. 512-835-2190.