Cover Story Disinfection
Cover Story Disinfection Measurement and Dosage in Bottle Washing made Easy What happens after you‘ve returned your bottle? A deposit bottle is usually cleaned, disinfected and refilled around thirty, up to fifty times. One such bottle washing system is located at Maisel‘s brewery in Bayreuth, Germany. The disinfection panel installed there not only provides precise measured values, but also controls the optimum disinfectant dosage. Challenge The cleaning process begins with the bottles being emptied of residue, presoaked and flushed out. They are then cleaned in alkaline solutions and water baths, disinfected with chlorine dioxide and finally rinsed. The challenge here is to dose enough chlorine dioxide to guarantee reliable disinfection. And at the same time keep the concentration low enough to save costs and protect the system from corrosion. Typical process challenges – especially all kinds of fluctuations – make chlorine dioxide measurement considerably more difficult. The ancient wisdom of Heraclitus – “nothing is as constant as change“ – applies in a particular way: In the form of temperature fluctuations, fluctuations in flow velocity and irregular downtimes (for example, due to maintenance and washing cycles). In addition, short-term pressure peaks pose a risk of damage to the diaphragm cap. And there is something else that favors incorrect measured values: The high dirt load in the medium. This means that the washing liquid usually contains a lot of label residue, which contaminates the sensor diaphragm. Measured values are the basis for the dosage. If they are incorrect, the chlorine dioxide concentration will be too high or too low. This not only results in high costs, but also puts people and machines at risk. “We were only able to develop this panel solution together because we all pulled together as partners. We have always believed in Endress+Hauser and have been very satisfied for years. I don‘t think it‘s an exaggeration to say that we now have the most stable measurement and control system in the industry,“ says Hannes Kauper Head of Filling and Brewing Technology Maisel Bros. Brewery. Solution In 2024, Brauerei Gebr. Maisel, together with Endress+Hauser, developed and installed a panel solution that makes the measuring completely self-sufficient and independent of these challenges. The result is a stable, low-maintenance and reliable disinfection measurement system that enables optimum dosage and works as follows: 1. Rinse water 2. Sample water 3. The upstream filter effectively protects the sensor from contamination and filters out all label residues. It is automatically backwashed every two hours via a fresh water valve (1) controlled by the transmitter. 4. The pressure regulator limits the pressure so that the sensor diaphragm does not rupture due to overpressure or underpressure. 5. The Flowfit CYA27 flow assembly for multi-parameter measurements with the chlorine dioxide sensor and flow measurement ensure a constantly sufficient flow for precise measurement. 6 food Marketing & Technology • August 2025
Cover Story Hannes Kauper (Dipl.-Ing.) at the transmitter that delivers more than just measured values Image source: Endress+Hauser 6. The Liquiline transmitter not only supplies the measured value, but also enables the panel with its control engineering to become a complete solution. In the panel itself, the transmitter controls the opening and closing of the flush and sample water valves, depending on whether measuring or flushing is taking place. In the process, it controls the dosing pump and thus enables chlorine dioxide dosing – optimized for the various operating modes (e.g. start-up, washing, rinsing, emptying or draining). The panel: Optimized for bottle washing processes in the food industry Image source: Endress+Hauser food Marketing & Technology • August 2025 7
