No loss of hops and malt with the right measuring technology
Active batch balancing & food conformity & CIP suitability
In the food industry, absolute hygiene is of crucial importance, with high demands being placed on the measurement technology to be installed in terms of design, functionality and reliability. In the beverage industry in particular, these requirements can be very specific.
A Peruvian beer manufacturer was looking for suitable solutions for overfill and running-empty protection for its process tanks with different solid and liquid raw materials. The malt dosing system was designed with innovative RF technology. Capacitive limit switches from UWT were installed, which are designed for high temperatures and applications with highly caking materials such as the viscous liquid of the malt mixture.
It tastes better when you know your limits
The difficulty in beer production lies in controlling the correct malt dosage during the addition of water for dissolving. This was due to the fact that the grain became very sticky after moistening, which led to false alarms for all test sensors. Together with the local UWT partner SIERRA Servicios Industriales SAC, a corresponding point level switch was therefore configured on site with the RFnivo® RF 8100 as a rod version including ”Active Shield” technology. This active compensation integrated into the capacitive measuring principle of the RF sensor ensures that the probe switches reliably and unaffected by material build-up. With an additional protective electrode, the probe can measure reliably even with highly conductive build-up and ignores deposits and build-up.
Based on the sodium hypochlorite used, the process temperature during the cleaning processes (CIP) can reach up to 80°C (176°F). The 250 mm long probe arm is therefore made of PFA-coated stainless steel, PEEK insulation parts and FKM seals. Ideal for withstanding the aggressive high-temperature cleaning process. In addition to the standard Ex approvals, the RF 8000 series is certified in accordance with Lloyd’s Register and WHG. The exclusive use of food-compliant materials for all measuring device parts that come into contact with the respective product was also essential. The dielectric constant of the viscous liquid is approx. 4.0 and the process atmosphere inside the stainless steel tanks is very vaporous. The robust limit level switches were installed in the side of the process tanks for demand indication and regulate the corresponding malt addition within a measuring range of 10 meters through rapid and precise material detection.
Capacity and frequency
A small change in capacitance results in a relatively large change in frequency. Because this capacitive measuring technology works with the practical ”Frequency Shift” technology, the change in frequency can be determined instead of directly measuring the capacitance.
If you have an empty container, the probe is not covered and the frequency is high while the capacitance is low. Now the container fills up, the probe is covered and thus the frequency falls and the capacitance rises. What is clear to see is that a small change in capacitance results in a relatively large change in frequency. The fact that the frequency can be evaluated means that even small changes in the fill level can be detected. This ensures very high measurement accuracy and the sensor can be set very sensitively.
As the capacitive RFnivo® level switches work universally and smoothly in bulk solids, granulates, powders as well as liquids, pastes and highly viscous oils, other silos, tanks and process vessels at brewery plants have been equipped with the level switches for full, demand and empty detection. The various device versions could even be used flexibly in hoppers, pipelines and downpipes. With the installation of the corrosion-resistant min/max indicators, the process sequences of the beer production facilities could be quickly and easily optimized with regard to overfill protection and empty protection, not only in the malt addition process.
