The mining industry relies on level measurement for a number of applications. In recent years, non-contact level measurement has gained more and more interest due to its simplicity and reliability. In this particular environment, where sensors are prone to damage, not being in contact with the material to perform the measurement is especially useful. Among non-contact level measuring instruments, laser level sensors have found many applications in this industry.

One of the benefits of laser level measurement products is their reliability since they are positioned away from the falling material preventing any damage. Also, their remote installation makes them easier to install and access. Efficient level measurement for blocked chute detection or crusher level control, for instance, pays for itself rapidly by enabling a continuous production and preventing the equipment to be broken.

Crusher level control with the ABB LM80 laser level transmitter is a typical application. Level measurement allows process optimization and prevents overfilling which could cause problems. The laser beam detects the rocks level accurately, even in the presence of dust. This technology is immune from the effect of noise, vibrations, ambient air conditions, and the material angle. Furthermore, since the laser beam is narrow, being only a few centimeters in diameter even at more than 30 m, it does not interfere with the vessel side or other obstructions.

Blocked chute detection is another typical application. The ore delivery needs to be stopped rapidly if a chute is blocked, which could cause significant damages otherwise. The laser beam allows level measurement deep in the chute even if the space is limited. The technology also responds rapidly (1s or less) to sudden level changes, which is required as clogged chutes can fill quite fast.

The ABB LM80 laser level transmitter is specifically designed for heavy industrial applications. Its rugged enclosure allows it to withstand being hit by falling rocks and its explosion proof certification is a necessity for several mining applications. The LM80 also comes with a variety of accessories made to perform in a mining environment. Dust tubes, attached to the front of the instrument prevent dust from reaching the lenses and a heated lens option can be used to prevent the formation of condensation, which would be detrimental to sensor operation.

ABB Inc., Québec, Québec, Canada 418-877-2944 www.abb.com

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