Pressure sensors guard optimal production processes

The Swiss group Barry Callebaut is the largest chocolate and cocoa producer in the world. When filling the storage tanks in Wieze, the group's largest chocolate factory and at the same time the world's largest, perfect hygiene is an absolute requirement. This process is reliably monitored by VEGABAR pressure sensors.

Barry Callebaut produces many tons of the very best chocolate and cocoa products every year at its more than sixty production sites worldwide. With more than 20,000 bioactive compounds, cocoa products are considered a new superfood. Therefore, like wine, the production of chocolate is a matter of skill and experience. In order to always have the required chocolate types available in the right quantities, they are housed in tanks and stored at a temperature of about 40°C. These double-walled tanks each have a volume sufficient to make 1 million chocolates. The tanks are heated with water, while agitators keep the liquid masses in the desired state. The two VEGABAR pressure transmitters, which determine two level values at the top and bottom of the tank and compensate relative to each other, reliably monitor the supply to the production line as a differential pressure measuring system. They transfer their measured values to the plant's process control system. Tanks whose level falls below a certain threshold are thus reliably refilled within the defined time window.

For application to chocolate tanks, VEGA recommended the use of VEGABAR pressure sensors with extremely robust ceramic measuring cell. In hygienic applications, front-bonded metallic membranes are usually the first choice. But with this special medium, the CERTEC^® measuring cell from VEGA has more to offer: it too is distinguished by its hygienic, front-bonded design and its modular connection concept. The VEGABAR pressure sensors are certified according to 3A and EHEDG and are resistant to high and even extreme temperatures due to their chemical resis-tance. They operate drift-free and oil-free. In addition, they are so robust that even solid, abrasive constituents in liquids do not affect them. Perfect for chocolate; especially since it is viscous and often sticky with a strong tendency to fouling. Measurement in storage tanks remains stable even with hard ingredients thanks to VEGA's robust ceramic measuring cell. Nuts or cocoa bean shells are therefore not a challenge.

At Barry Callebaut, VEGABAR pressure measuring instruments have been holding up reliably and virtually drift-free to the demanding challenge called chocolate since 1990. Drift is a phenomenon that creepily makes its appearance in pressure measurements. Sensors with metallic measuring cells must take this into account. The more often the thin metal diaphragm is loaded, the less well it returns to its specified zero point. For the user, this means additional work (recalibration). In contrast, the ceramic CERTEC® measuring cells operate practically drift-free. The hardness of ceramic restricts the degree of movement to such an extent that significantly less material fatigue occurs, resulting in much longer recalibration cycles.

At Barry Callebaut, they are ready for the future: from new creations for gastronomy to kitchen glazes on sale in discount stores. And so is the measurement technology in the storage tanks. The applied electronic pressure measuring technology contributes to the safe management and the precise and efficient control and regulation of the process. In principle, all VEGABAR pressure sensors are suitable for this measurement principle, as they can be combined with a second sensor to form an electronic differential pressure system. Compared to a conventional measurement solution, the installation procedure is simplified because it is possible to work without thermal insulation. At the same time, the combined measurement system enables higher accuracy while no temperature influences need to be taken into account. The sensors are connected via a cable and each installed separately.

Regardless of the quality of the final product: the Barry Callebaut philosophy means the same uncompromising care for the entire production line - from the raw materials used to the measurement technology. Using the VEGABAR differential pressure measurement, Barry Callebaut in Wieze can run automated processes and guarantee constantly filled tanks. This ensures interruption-free production and reliably prevents costly process interruptions.