Beer brewing is craft where the same raw materials have been used for production for centuries. The single steps – milling, mashing, lautering, wort boiling, fermentation and conditioning, filtration and bottling – must be carefully controlled and coordinated so that the finished product reaches the consumer in a consistent quality. As a manufacturer of a product subject to purity regulations since 1516, a beer brewer naturally is especially committed to keeping the environment clean as well. After all, every brewery not only produces heat, odor, exhaust air, CO2 etc. but also waste water which accumulates when tanks and containers are rinsed and cleaned, in the brewhouse and in the fermenting and storage cellar. An environmentally friendly manufacturing process is required for environmental protection and business management reasons. The Binding brewery based in Frankfurt/Main is an example of this: here waste water is monitored with regard to pH and temperature values with the aid of Knick analyzers.
The Radeberger Group
The Binding brewery located in the district of Sachsenhausen belongs to the “Radeberger Gruppe AG“, as it has been officially called since August 2002. Known brands of the second largest brewery group in Germany are Schöfferhofer Weizen, Clausthaler alkoholfrei, Selters mineral water, and of course Radeberger Pilsner. Regionally leading breweries such as the Dortmund Actien brewery, the Berlin Kindl brewery, Binding and Henninger-Bräu in Frankfurt/Main, as well as the Krostitzer brewery and the Erbacher and the Allgäuer Brauhaus also belong to the holding. The Czech brewery Krusovice just outside Prague rounds off the portfolio.
Committed to environmental protection
All companies belonging to the group have an environmental management system. The Binding brewery is certified according to DIN EN ISO 14001. A large number of measures serve the prevention and reduction of emissions. Thus sealed machines prevent the formation of dust during delivery and malt milling. Waste heat generated during mashing is utilized by means of a kettle vapor condenser. The use of such a machine reduces unpleasant odors during wort boiling. CO2 generated during fermentation and conditioning is collected, purified and reused during bottling.
Controlling water and waste water flows
Water is naturally required for brewing – but not only as a raw material. Machines and equipment must be cleaned or disinfected in many process steps. Production changes for different beers also require rinsing and cleaning. The waste water ordinance of the city of Frankfurt stipulates specific temperature limit values and permissible pH ranges for waste water discharged into the sewage treatment plant via the city sewerage system. In such an extensive production facility where acid and alkaline waste waters accumulate at different temperatures, meeting these requirements is not a trivial matter. The environmental protection officers of the Binding brewery tackled the problem with an analysis of the waste water flows. Internal workflows were optimized based on this and a pH and temperature measuring system was installed which enables adherence to the limit values. The acid and alkaline waste waters can thus be used for mutual neutralization.
Process analysis requirements
The requirement profile for the employed analyzers resulted from several factors. “In the best of all possible worlds“, says Erwin Grävenstein, an employee in the technical services and maintenance department at Binding, “it naturally would be possible to optimally plan and build a completely new system.” However “historically grown” measurement and bus equipment actually exists into which new devices have to be integrated with their communication and mechanical technology as smoothly as possible. Uncomplicated parameter setting is also important. Furthermore the housing must reliably protect the electronics from the heat and humidity which always develops in a brewery. And of course properties such as high reliability, operational safety and measurement accuracy are also required.”
pH value and temperature
The experts at Binding opted for the Knick Stratos® PROFIBUS 2221 X pH. The possibility to measure two quantities simultaneously is also an advantage during mechanical integration: it was possible to use existing flanges at Binding. The analyzer is suitable for operation in hazardous locations up to Zone 1 (II 2(1) EEx ia IIC T4) and is housed in a rugged PBT enclosure (IP 65). Installation is easy thanks to plug-in terminals and the pre-assembled housing.
Data exchange via the PROFIBUS-PA is effected according to the current profile 3.0 and the communication model of the PROFIBUS user organization. Thus the devices can be connected directly and without any additional effort to visualizations and controls. The certified PROFIBUS conformity ensures access to all relevant device and measurement data including calibration results. The simultaneously measured pH and temperature values are relayed cyclically to the superordinate control. The logbook and other device data are transmitted acyclically. Power is also supplied via the bus. The PROFIBUS PA address can be set on the device directly on-site.
The large display simultaneously shows the pH (or oxidation reduction potential) and temperature values. Status and alarm indicators provide information on operation and signal operating states (measuring and calibration mode, alarm, bus communication and configuration). A clear menu with an icon-led, easily understandable interface ensures high user friendliness during operation on-site. Calibration can be carried out in three ways: with conventional buffer sets, manually or via direct input of zero point and slope. A calibration timer is integrated; Sensocheck® continuous sensor monitoring and the automatic GainCheck® device self-test guarantee reliable function of the device. The glass and reference electrodes are continuously monitored, electrode defects are reliably detected.
Conclusion
“With the use of Stratos analyzers we have come one step closer to achieving the goal of optimizing our equipment so that our production methods are as environmentally sound as possible“, Erwin Grävenstein concludes. Simultaneous determination of two measured values, high measurement accuracy and easy integrability into the existing equipment were the decisive arguments for using Knick devices for waster water monitoring.
