Abstract

Minerals processing has some unique and demanding flow measurement requirements. To date, these requirementshave not been adequately met by traditional flowmeter technologies such as electromagnetic flowmeters or Doppler flowmeters. Within the past decade a new flow measurement principle that overcomes many of the disadvantages of the traditional approaches has been discovered and has been placed into practice. This technology is based on the combination of an axial array of passive sensors wrapped around the outside of the process pipe and powerful array processing algorithms to accurately determine the volumetric flow rate of most fluids including gases, clean liquids, and slurries as well as liquids and slurries with entrained air. In addition, this technology can measure the gas void fraction or the amount of air entrained within slurry or liquid flow. The principle of operation for both volumetric flow rate and entrained air measurements will be described, along with the capabilities and operating range of this technology. This technology has proven its ability to provide accurate, reliable flow measurements in the presence of slurry containing magnetic properties such as magnetite, ferrosilicon and pyrrhotite and slurry containing entrained air bubbles, highly abrasive slurries, and scale buildup on the interior of pipe walls. Applications in hydrocyclone monitoring and nuclear density gauge correction will be covered.