Demand-oriented filter cloth cleaning in breweries with positioning systems


Plants in the beverage industry are subject to strict hygiene regulations. What is more, cleaning filter cloths in the brewhouses of breweries and fruit juice production poses particular challenges. On one hand, most filter cloths are difficult to access. On the other, cleaning is made difficult by the weblike structure of the filter cloths. The Chair of Brewing and Beverage Technology at the Technical University of Munich is currently doing research on an automatic and need-based filter cleaning method. The PSW positioning systems from halstrup-walcher are being used for this.

In order to remove mash separation residue on the filter cloth as needed, the water nozzle with PSW positioning system is moved into the correct positionzoom

Optimised filter cloth cleaning process


The Weihenstephan Science Centre of the TUM is a special place. The art of brewing beer is studied and researched here. The task of the research project “In-situ cleaning of membrane filter presses” (IGF 19716 N) was to efficiently clean filters contaminated by mash separation with state-of-the-art technology in as little time as possible and using as few resources as possible. Pressing the mash leaves residue on the filter cloth. The brewing process must therefore be regularly interrupted for filter cloth cleaning. The cloths are then manually and evenly cleaned with a hose or in an automated “wash system”. And yet the actual degree of contamination is not considered. On the other hand, the innovative cleaning method on which the TU of Munich is currently working is fully automatic and specifically cleans the contaminated spots. For this purpose, a pulsatile-driven jet lance, an optical camera unit for residue analysis and the PSW positioning systems from halstrup-walcher are used. The camera photographs the dirty filter cloth. Even the tiniest impurities can be detected by photo analysis with software. Their position is transferred into a coordinate system. These coordinates are relayed to the positioning systems. The positioning systems consequently move the nozzle to the correct position. In the process, the synchronised water jet achieves a better cleaning result, while at the same time less water and fewer cleaning agents are required.


Precise positioning systems for hygienic applications


The precise positioning of the water nozzle would not be possible without the PSW positioning systems. With IP protection class 68, the drives in the stainless steel housing are best suited for wet areas and hygiene applications. Positioning systems from halstrup-walcher have already been used for years by well-known beverage plant manufacturers, who have been very satisfied with them.

One of the PSW positioning systems on the test bench at the Weihenstephan Science Centrezoom
One of the PSW positioning systems on the test bench at the Weihenstephan Science Centre

The PSW positioning systems are made up of a brushless EC motor, a gearbox, an absolute distance measuring system, an engine control and are self-monitoring. The integrated bus communication gives the PSW the drive command to a desired position of the control unit. It also provides acknowledgement of whether the target value has been achieved within the scheduled time. To precisely achieve and maintain the desired position, the PSW has an integrated distance measuring system. Because the positioning systems from halstrup-walcher work without batteries, a change to the position, e.g. by manual adjustment, is also recorded and forwarded to the control unit, even when no voltage is applied. In the course of this, the absolute measurement system does not measure the revolutions on the motor, but directly on the output shaft. Gear backlash is thus not relevant for measuring accuracy.


These characteristics of intelligent drives make halstrup-walcher an optimal partner for research work at the TU Munich’s Weihenstephan Science Centre. Mr Roman Werner, tutor of the in-situ cleaning project, is very happy: “The positioning systems from halstrup-walcher work flawlessly. For adjustment of the motor parameters and thus teaching the individual coordinates, we have been assisted by halstrup-walcher’s Development Department.”


Practical research project with substantial future prospects


For the project, testing is carried out with the aid of a membrane filter press from the mash separation. After the cleaning method becomes suitable for practical application at the end of 2020, it is expected to be developed for other filter cleaning applications. The most obvious applications are also in the food industry. Juice plants for instance can benefit from the innovative filter cleaning method. But using it in the pharmaceutical sector is also conceivable. However, because more intensive residue must be removed here and an antiseptic state is required after cleaning, the expansion of filter cleaning must be sector-specific. The intelligent drives from halstrup-walcher can likewise be used for future applications.

Mr Roman Werner, research fellow at the Chair of Brewing and Beverage Technology at the Technical University of Munichzoom
Mr Roman Werner, research fellow at the Chair of Brewing and Beverage Technology at the Technical University of Munich