Processing Magazine

Triboelectricity put to good purpose

December 6, 2013

Auburn Systems U3000 bag leak detectorThese electrostatic/triboelectric bag-leak detectors, emissions monitors and solids-flow monitors measure particulate and dust emissions — as well as dry solids — in process-flow applications.

A proprietary technology, TRIBO.dsp, unifies direct-current (DC) impaction, i.e., triboelectric, and alternating-current (AC) induction electrostatic signals for superior instrument accuracy, reliability and repeatability, says Danvers, Mass.-based Auburn Systems.

Triboelectric denotes a kind of contact electrification. Most everyday static electricity is triboelectric.

The solution works like this. As dust particles collide with or closely pass by a probe, charge transfers occur. The instrument detects the signal created by particulate concentration changes, as in bag-leak onset or flow increase and decrease. Unlike monitors that use only DC or only AC induction signals —  thereby using only a portion of the complete electrostatic signal — these instruments combine each method’s benefits, for a reliable and repeatable signal, with electrical interference resistance, even in harsh environments.

The result of a two-year design and development project, TRIBO.dsp applications include the following:

Dust-collector monitoring can warn of impending filter-failure shutdowns, eliminating the guess-work of isolating compartments or performing dye tests. It can safely extend filter media use, for fewer maintenance shutdowns.

Loss-of-flow detectors — closely related to dust-emission bag-rupture detectors — are found in many flow applications, including early detection of ambient or fugitive dust; blockages or no-flow detection in pneumatic-conveying or material-handling systems; screw-feeder material injection; or in the velocity of particles.