San Diego, California-based Mother Earth Brew Co. started in a small garage and grew to a tap house to a production facility in just six years. In 2016, the company’s growth called for an additional production site.
Mother Earth’s executives chose a new 40,000-sq-ft space near Boise, Idaho, with a 50-bbl, four-tank craft brewery, and engaged Paul Mueller Co. to engineer the process, brewhouse and piping and Rockwell Automation Solution Partner Stone Technologies Inc. to provide the automation. The goal was to design a new facility that could maintain the flexibility needed to uphold and expand the company’s eclectic collection of craft labels. Chris Baker, head brewer at Mother Earth Brewing Co., oversaw the project.
Baker and Ryan Williams, project manager, Stone Technologies Inc., shared their experience and lessons learned from the greenfield installation at the 2016 Process Solution User Group (PSUG) conference held in November in Atlanta.
Along with recipe flexibility, the automation system handles energy recovery, process-value-dependent routines and an innovative approach to clean-in-place (CIP). The controlled equipment includes:
- a mash mixer to mix crushed grain and water under controlled pH and temperature;
- a lauter tun, where grain and liquid wort are separated and solids are extracted using a rake mechanism;
- a brew kettle to boil, concentrate and sterilize the wort and to add hops;
- a whirlpool filter to further separate solids and deliver cool wort;
- fermenters, where temperature is controlled closely to prevent off flavors;
- a centrifuge with a 10-micron lenticular filter to clarify the brew;
- and “bright beer” storage before carbonation and packaging.
The system has to handle a variety of recipes. “We typically brew seven varieties of beer in a given week, and 60 or 70 varieties over the course of a year,” Baker says.
Reliable, Repeatable and Flexible
“Automation makes craft beer reliable and repeatable — you’re not dragging hoses around — while providing the knobs brewers need to twist to keep it craft,” explains Williams, project manager, Stone Technologies Inc.. With that flexibility, the system had to allow for expansion and handle several non-brewing capabilities, all with “an information-driven interface for nontechnical users,” he adds.
The PlantPAx®-based system from Rockwell Automation uses Sequencer Object for sequencing control, Batch Scheduler for scheduling and starting times and separate parameter values for non-brew operations including CIP. “The CIP sequences use the same Sequencer Object instruction as the brew process, since all the control functions are the same,” Williams notes.
Instead of a separate CIP skid, the system “uses the vessels themselves as washing machines,” Williams explains. “The process equipment has cycles to clean one, trigger the next, add caustic, etc. They can clean all four circuits at one time, which they couldn't do with a CIP skid.”
Approximately 50 parameters are associated with the equipment, and about 50 variables can be used as recipe parameters, including CIP. “These are the ‘knobs’ they can turn to get the taste and characteristics they’re looking for,” says Williams.
“The displays are a compromise of grayscale for situational awareness, and color they wanted to make them happy,” Williams adds. “Sequencer Object gives a very good, in-depth visual of sequencing, a powerful addition to the PlantPAx library.”
An Allen-Bradley® ControlLogix L72 processor and server-based FactoryTalk View SE HMI software from Rockwell Automation allow for expansion. “The kettle is the bottleneck now, and they might add another, with more pumps and valves,” Williams says.
Allen-Bradley Flex™ IO, PowerFlex® drives, valve manifolds on EtherNet/IP™ from Rockwell Automation Encompass™ Partner Festo Corp., and SQL tag storage round out the system specifications.
“We use a spreadsheet tool to create an I/O list, and a routine builds the base PlantPAx program,” Williams explains. “Then we can go in and configure the I/O. We’re able to do that without going into every routine, every add-on instruction. We can see it all in one picture, and, when we’re done, it becomes part of the documentation.”
The system also collects heat from the “knock-out” of the brew kettle. “The wort comes out at 190 °F and has to be cooled to 60-70 °F for the yeast,” Williams says. “We’re collecting that heat and putting it back in the hot water system.”
Automated sequences are engaged based on differential pressures, and hot and cold water flows are balanced “so the water tanks don’t overflow,” Williams adds. Batch numbers are being created for future reporting features, and historical data is being taken for when it’s needed later to come up with new brews, or to increase throughput or efficiency.
Lessons Learned
Lessons from the project include involving the customer early and thoroughly. “Chris was involved from the beginning, in the process of functional spec creation and through factory acceptance test (FAT), checkout, water batching and commissioning,” Williams says. This resulted in very fast customer ownership.
“PlantPAx provides an excellent interface with users, allowing them to control a process without a need to understand PLC programming,” Williams continues. “And our use of development tools such as Excel creates a consistent and structured program.”
In the end, “No matter how much planning is done and how many meetings take place around the functional spec, there are always modifications needed and requested during startup,” Williams says. “Sequencer Object and PlantPAx make those modifications very quick, often with no need to open a PLC program.”
Stone Technologies, a Rockwell Automation Solution Partner, is a national systems integrator based in St. Louis focusing on consumer products, life sciences, and fine chemical industries. The company provides operations consulting, MES/MOM and process control design, development and implementation for smart manufacturing solutions.
Learn more about Rockwell Automation Food and Beverage Solutions.
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