Electricity and Control September 2020

MEASUREMENT + INSTRUMENTATION

Sensors ensure a smooth brewing process

Skanderborg Bryghus in the Danish town of Skanderborg produces a variety of individual beers and unlike large commercial breweries, this brewery is largely promoted and operated by beer lovers on a voluntary basis.The demand for its products proved so substantial that three years after its foundation the brewery had to be expanded significantly. At the time, sensors from ifm were selected and installed to monitor the numerous tanks.

A llan Pedersen, Technical Manager of Skanderborg Bryghus, present from day one, explains. “In 2015 our company started with a brewing capacity of 125 000 litres of beer per year. In 2018 and 2019 we ex- panded the brewery significantly so it now has a capacity of four million litres per year.” The expansion of the plant was carried out by the com- pany GEA. Kåre Hjortkjær, GEA Denmark, was responsible for the electrical work. “GEA is an international engineer- ing company. We make process systems for different in- dustries. For this project we developed a completely new brewery,” he says. “It was our responsibility to decide on all sensors to be used in the process. The customer did not require specific product brands, although the price was, of course, part of the decision. All the factors we considered pointed to ifm. “We selected the sensors needed for process monitor- ing because of their flexibility and focus on the hygienic design. One requirement, for example, was to detect the level in a tank and to differentiate between beer and CIP liq- uid. We decided on sensors from ifm because we know the company from many years of good and close cooperation.

Skanderborg Brewery is characterised by its many different beers.

“We measure pressure and temperature at several points in each tank and also monitor level. To do this, we installed several ifm sensors at each tank. The controller visualises how much beer is in the tank and what temperature it has. The many sensors make it possible to run the brewing pro- cess automatically so production can be controlled with a minimum of employees.” Allan Pedersen adds: “GEA installed more than 300 ifm sensors. We can remotely set, calibrate and monitor them via IO-Link. We are happy that we can use the complete solution of one supplier instead of having to buy compo- nents from different manufacturers.” Most ifm sensors are installed at the numerous tanks. Three types of sensors are used especially frequently. Pressure sensors ensure a smooth process An ifm pressure sensor, type PI2795, is mounted at the bottom of the tank. The level is determined via the hydrostatic pressure the beer in the tank exerts on the sensor’s measuring cell. The measuring range of the sensor is -1 to 4 bar. It is resolved in steps of 0.005 bar. The measured value is transmitted to the plant controller via an analogue signal or IO-Link. Since the tank geometry is known, the controller calculates the exact contents in litres from the measured pressure.

Pressure sensors for hydrostatic level detection (left) and temperature transmitters (right) are used to ensure a reliable brewing process.

16 Electricity + Control SEPTEMBER 2020