Valve control heads help increase protein levels in milk

Apr 3, 2012 | Food Processing & Packaging

Problem: Fromagerie Bel, the agrifood production company behind such brands as Mini Babybel, processes 110 million litres of milk and produces 12,000 tonnes of cheese per annum at its Cléry-le-Petit site in France. Milk collected in this region is quite low in proteins, so just about unusable for cheese. Also, the milk, which represents about 50% of the price of cheese, has a significant quantity of lactoserum, which has no value but still remains, at the expense of the cheese factory.

Solution: To solve the problem new vats have been installed. The vats’ flow management system, provided by Tetra Pak, adds an extra protein constituent  to the milk. Control of the flow management system is provided by 180 fieldbus controlled valves, all of which are equipped with Bürkert 8681 series universal control heads.

The control heads are designed for decentralised automation systems using ASI communications. They can be used on most process valves and offer control and diagnostic safety thanks to remote visualisation of the positions of the respective valves. The 8681 units execute all pneumatic commands, position feedback functions and diagnostics, and depending on the process valve, can control up to three pneumatic chambers separately.

After installing the control head on the valve actuator, the positions of the valve are determined automatically by a ‘teach-in’ function which eliminates the need for configuration and manual adjustments. Start-up times are reduced by self-setting limit switches in an Autotune function.

The control head offers IP65/67 ingress protection, so has good resistance to chemical cleaning products, and a magnetic control key, which prevents the control head from being opened on site after commissioning. The 8681 enables instant visual diagnostics of the valve status by colour coding (Open/Closed/Error) that can be seen from up to 100m. In addition, a large format visual luminous colour display unit signals valve positions, operating errors, anomalies in communication with the bus and mechanical blockages in the valve.

Operational flexibility is enhanced by a feature that allows the switching speed of each driver chamber to be set individually for both directions of movement.


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