New control system architecture allows brewery to meet its goals

At first sight, the important role that a small 15-barrel brewhouse plays for a major global brewer would not be suspected, says Michael McEnery, president of McEnery Automation, a certified member of the Control System Integrators Association (CSIA). But as the beer market’s thirst for new flavors and styles increases, the ability to develop new products is more critical than ever. 

Originally built 35 years ago, this small brewery is a state-of-the-art facility where brew masters create new recipes, experiment with ingredients, and explore new brewing techniques. According to McEnery, the increased focus on product and ingredient development placed new demands on the brewery’s control system, including more flexibility for process modifications, increased recipe management requirements, expanded use of process data, and a greater need for system reliability. 

The brewhouse required frequent process and recipe modifications, but automation changes were difficult to make due to the age and limitations of the existing legacy control system. “To make matters worse, end-of-life equipment put the brewery at high risk of not being able to recover from a programmable logic controller (PLC) or server crash,” states McEnery, who implemented the brewer’s new system. 

McEnery Automation followed CSIA industry best practices and invested time early in the project to understand and document the customer’s requirements and expected results, as well as provide advice on how to avoid potential future limitations and inefficiencies. McEnery Automation’s engineers worked closely with the brewery to develop a complete understanding of its brewing and clean-in-place (CIP) processes, capturing each brewing vessel’s process in detail via flow diagrams and descriptions of operation documentation. McEnery Automation then designed a new control system architecture, which would allow the brewery to meet its goals. 

“Flexibility and ease of modifications to recipes were top priorities for the pilot brewery,” McEnery says. “Multiple design reviews with both operators and supervisors ensured that the recipe management interface was intuitive and easy to use.”

Integrating recipe storage with an existing manufacturing execution system (MES) database allowed for an unlimited number of master recipes. Identifying key process parameters and exposing them as recipe values allowed for tighter control of the process. On-the-fly recipe parameter changes provided additional capability for quick reaction during development of new products and processes.

In addition to eliminating end-of-life controllers, the system reliability was increased by using a redundant server pair for the HMI operator interface and process historian as well as automated daily backups of programs. 

According to McEnery, a process historian was implemented to capture and store valuable process data to verify proper process operation and analyze quality data for new products and ingredients. Process alarms were integrated into an existing alarm messaging system.

By incorporating an in-chassis Profibus gateway module from a third-party supplier, the PLC platform was able to communicate directly with the existing Profibus I/O hardware. This allowed all existing wiring to be left in place, reducing the overall project cost and minimizing system downtime.

“Extensive simulation and testing with the customer prior to installation provided multiple benefits,” says McEnery. “It allows end users to verify proper process operations, provide feedback regarding ease of use of HMI graphics, and receive valuable operator training. The time spent in design reviews, simulation and testing paid dividends throughout the project.” Overall costs were 20 percent under budget, and system downtime for conversion was kept to a minimum with no unplanned delays, overtime or lost batches. Production mode was achieved two weeks ahead of schedule, and post-startup modifications required less than 2 percent of the overall project budget.

Increased system flexibility allowed the brewer to make most process changes itself without making programming changes to the PLC and HMI. Integration of alarms into a messaging system provides faster response times, especially during off-shift hours.

But most importantly, says McEnery, the increased flexibility and accuracy of the control system now allows the facility to support the product innovation required to compete in the changing beer market.