Kefir und Kakao non-stop

NÖM's fresh produce warehouse is manned 24/7. It works around the clock to get the products made from the delivered raw milk ready for delivery as quickly as possible. "Over the course of a year, we process around 420 million kilograms of raw milk into yoghurt, curd cheese, butter, cocoa, kefir, protein drinks and much more," says Christina Keil, emphasising the diversity of the Nieder- österreichische Molkerei's product range on the one hand and the quantities of milk it has to deal with on the other. The raw milk is delivered daily, at least one million litres per day from a total of 2,500 family farms in Lower Austria, Burgenland and Eastern Styria. This means that longer plant downtimes are a no-go in Baden, especially as this is NÖM's only production site. This made it all the more bitter for Michael Hronek, automation engineer and head of control technology, when the muting relay previously used, which fulfilled its task for around 30 palletiser entries and exits, was discontinued without an adequate successor model even being offered.

"The problem was that it was not so easy to replicate the existing application, because in our case the higher-level control system is integrated into the muting. And this should not be aware of the necessary conversions," he explains. It was therefore necessary to imitate the functionality of the existing evaluation relay and its interaction with the light grids from the same manufacturer 1:1. A challenge that the system integration experts from Pilz mastered with flying colours, as Michael Hronek praises: "Everything really worked out perfectly, from the planning to the installation of the new components and the safety-related acceptance. And our 'saviours in need' were also extremely flexible in terms of time." The configurable small controller PNOZmulti 2 from Pilz took over the infeed and outfeed of the goods. It ensures that any desired short-term bridging of the installed safety function is implemented - in other words, that the muting functions smoothly. All changes affecting the small controller PNOZmulti were synchronised with the CIP cleaning, the Cleaning in Place, which takes place every few days. To avoid further downtime, Pilz completed the installation of the automation system PSS 4000 for multiple stations in one weekend. "Even the sales department got involved so that everything went as quickly as possible," says the Head of Control Technology at NÖM, alluding to the fact that even his main contact Markus Stockhammer, Solution Sales Manager at Pilz Austria, lent a hand during the conversion phases.

Two of NÖM's three large palletising systems were converted. This involved replacing both the relays and the light curtains previously used. This was because a combination of both was absolutely necessary for the previous opto-electronic protective system to be used as intended. "When we were presented with a solution that harmonised with a wide variety of safety devices, as long as they could be operated on two channels, Pilz opened the door for us. After all, especially in times like these, when there are supply bottlenecks for many products, it is important to be as flexible as possible," says the Head of Control Technology, who would generally like to see less proprietary products in the world of automation. Pilz took over the engineering for NÖM and programmed a 1:1 replacement that fulfilled everything on the list of requirements: reliability, a high level of safety at the current state of the art, easy adaptability to new conditions - and therefore future-proof - as well as a solution from which the higher-level plant control system remained independent.