South West England
Temperature control, level sensors, valve actuators, graphic control panel, PLC
Stroud Brewery needed to develop from making beer by hand, to a more automated and process, in order to expand and modernise their business. It was essential to preserve the best aspects of the traditional brewing process, and replicate the quality of the handmade product, but with better control, higher output and less stress for the workforce.
Greg Pilley the brewery founder explains why retaining the original process was so important:
‘At Stroud Brewery, we produce a range of three regular beers: Budding, Tom Long and Stroud Organic Ale. Running the original brew house at full capacity was a decidedly nerve-wracking experience that did not allow any room for error. It also made for difficult working conditions with everyone working flat out as a team, none of us find it very easy to have holidays without doubling the workload of somebody else, you can't be sick, and we certainly can't afford to have any problems in the brewery.'
Burkert's systems engineering team helped complete the evolution of this traditional organic craft brewery into a modern microbrewery.
Bürkert brought in a small level of control technology, helping monitoring and control of the whole process. A control panel with a PLC and a graphic colour display was designed and built. This shows the different tanks and piping, and the different points where level and flow are measured.
Lars Frimert, Area Sales Manager for Bürkert explains: 'When Greg from Stroud Brewery came to see us, and explained what needs were, we listened hard, and we managed then to translate that to a visual control system that is easy to use and practical for this tough working environment.
The system controls eight processes within Stroud Brewery. There are three main ones:
‘The first is the strike temperature control, where we control the temperature from the cold liquor tank and the hot liquor tank going into the copper, where it’s been mixed with the grain into the mash tun. It’s very important that the temperature is correct, and with the help of our temperature probes and our control system, we control the speed of the motors to achieve that precision.
‘The next one is the run-off from the mash tun. This was previously a very labour-intensive process, where you needed to look at the vessel continuously. We solved that problem by putting three level-sensors in the vessel. The control system uses the information from those level-sensors, and controls the run-off, so you never run dry or overflow. With that, the head brewer, or the brewers can walk away and can do other things during that time.
‘The third key process control of the temperature of the fermentation vessels. They can’t be too high or too low. The control system reads from our temperature probes what the temperature is, and adjusts that accordingly; we then either cool it, with the water from the chillers, or we heat it via a heating pad.
The new brewery equipment allows Stroud Brewery to brew four times as much beer in a single day as before, while maintaining identical quality.
Greg Pilley said: 'We now have a basic level of automation that still provides us with hands-on control when we need it. We haven’t gone overboard with it; by the use of food-grade level-sensors, flow-meters, and an intelligent control panel, we now don’t have to stand over the process continuously and that has enabled us to grow the capacity of our brewery without compromising on quality.’
This application combines traditional processes with the latest automation systems, allowing old techniques to meet with new control technology.