A Conductance Based Solids Concentration Sensor for Large Diameter Slurry Pipelines

Abstract

An instrument has been developed that measures the solids concentration in slurry pipelines ranging in diameter from 5–150 cm. The operating principle is based on conductance, and in contrast to the gamma densitometer, the instrument does not require a nuclear radiation source. The instrument operates on-line, is nonintrusive, and provides real-time output. The instrument measures local concentration around the pipe periphery, and the local values are integrated to obtain the area-average concentration. A graphical display shows the variation of concentration from the top of the pipe to the bottom as well as the area-average concentration history. The instrument has been extensively tested in an experimental slurry transport facility as well as on-line at the Swift Creek phosphate mine in the state of Florida. When compared with a quick-closing valve measuring technique, the mean deviation of solids concentration measured with the conductance based instrument is 0.81 percent based on mass. [S0098-2202(00)00704-5]