Strides Made in Level Measurement
Maintenance-free rotor series MBA800 complies with ATEX
In the bulk materials segment, the use of certified devices is of particular importance given the risk of dust explosions. Inadequate protection against explosion can result in consequential damage in silos, mills and other contained facilities. Combustible dusts, encountered, for instance, during the manufacture and storage of grain, feed and fertilizers, frequently ingress into the hazardous range, even reaching the explosive limit. It is specifically fine dusts that generally react with greater intensity than do those with larger grain diameters. Aside from the respective bulk material properties, further factors, such as structural specifics, potential sources of ignition and the quality of the devices deployed, are important aspects to consider during risk assessment. The fact that explosive dust mixtures can occur in various parts of a facility is exemplified by concentrated feed plants. Here, among other things, dust mixtures can occur during vertical, pneumatic grain filling and the filling of dust-producing materials, as well as in downpipes, filling hoppers, silo chambers or cyclones.
The German company MBA Instruments GmbH factored in all these influencing variables when developing its digital rotor series MBA800. The series’ devices comply with ATEX Directives and are, moreover, particularly flexible in terms of handling. With the novel, stepper motor-based level measurement devices in the MBA800 series, MBA Instruments meets the most stringent requirements as standard. Suitability of the devices in explosive zones is – in addition to a host of technical refinements – one of the stated goals of the developers. With the ATEX Type Examination, concluded in 2016, the rotors’ potential deployment in areas prone to dust explosion has now also been officially confirmed. They comply with Directive 94/9/EC as well as the fundamental health and safety requirements stipulated in EN 60079-0:2012 + A11:2013 and EN 60079-31:2014. Category 2D devices are suited to Zone 21 areas. Subject to certain conditions, the shaft in equipment category 1D may also be deployed in Zone 20 areas. The rotors are thus optimally suited to deployment within the explosive bulk materials segment.
