The principles of the barley malting process are quite traditional. A traditional floor malting germinates the grains on a solid floor, with the grains manually raked and turned to keep them loose and aerated. However, UK producer Muntons relies heavily on automation, electro-mechanical equipment and sensors, to provide fine control over air flow, heat and moisture. Fans and motors are critical to the operation; Muntons processes many tonnes of product at a time, with key operations relying on a steady supply of blown air.
The impetus for the SCM installation came from issues previously experienced with difficult-to-reach bearings inside a large fan housing. A bearing failure inside a fan assembly caught the engineering team unawares and proved significant in terms of downtime. “We only realised we had problems when it was too late, and had to make an unscheduled stop to make repairs,” says plant engineer Michael Plawecki.
Determined to learn from that lesson, Muntons looked for a monitoring solution with predictive maintenance technology that could be linked into the company’s existing SCADA system. Its requirement was for a system that would provide the maximum forewarning of any problems, yet which would be quick and easy to install. “We found what looked like an ideal solution in the form of the SCM from Mitsubishi Electric,” adds Plawecki.
The chosen SCM installation provides condition monitoring for two large 315kW fan sets and a single 90kW fan set. Sensors monitor the electric motor, power transmission coupling and main fan shaft bearing on each fan set. Plawecki explains: “We now have a clear picture of the health of the fan sets and advance warning of any required maintenance. Remote monitoring and fast diagnosis of any issues has also made us very responsive should the limits on operating parameters that we have set be approached. The system was easy to install and relatively simple to commission.”
The SCM solution comprises smart sensors that can be attached to bearing housings, gearboxes, pumps and motors, to detect when equipment starts to operate outside its normal envelope, due to wear. It also provides an early warning system for critical pieces of rotating plant equipment. Vibration frequencies and temperature readouts are monitored and fed back to an L Series Mitsubishi Electric PLC, via an industrial Ethernet network cable.
The PLC offers simple integration to other network system hardware and software platforms, in this case integrating with the SCADA system at Muntons Malt. The sensors, developed by bearing expert FAG, monitor for changes in the complex vibration patterns, specific to the type of equipment it is attached to.
Live information and any alarms are also displayed on a Mitsubishi Electric GOT Series HMI mounted to the control enclosure. The system can work autonomously, with multiple sensors located and recognised by unique IP addresses. At Muntons, the visual information and the alarms being generated were easily connected into the existing automation software platform.
“We are reviewing the entire facility now to make a decision on which other parts of the plant we include, with the aim of speeding up maintenance,” concludes Plawecki. “We recognise that the investment in automation and predictive maintenance pays off very quickly by avoiding unscheduled downtime but can also be used to increase operational effectiveness and productivity.”