A conductance based solids concentration sensor for large diameter slurry pipelines

An instrument has bern developed that measures the solids concentration in slurry pipelines ranging in diameter from 5-150 cm. The operating principle is based an conductance, and in contrast to the gamma densitometer, the in strument does nor require a nuclear radiation source. The instrument operat es on-line, is nonintrusive, and provides real-rime output. The instrument measures local concentration around the pipe periphery., and the local valu es are integrated to obtain the area-average concentration, A graphical dis play shows the variation of concentration from the top of the pipe to the b ottom as well as the area-average concentration history. The instrument has been extensively tested in an experimental slurry transport facility as we ll as on-lint at the Swift Creek phosphate mine in the state Of Florida. Wh en compared with a quirk-closing valve measuring technique, the mean deviat ion of solid., concentration measured with the conductance based instrument is 0.81 percent based on mass.