Particle concentration characteristics and density measurements of slurries using electromagnetic flowmeters

摘要

DC type electromagnetic flowmeters generate signals proportional to the flowrates of fluids in closed pipes. These signals are processed suitably for flow measurements. However, further studies indicate that the generated signals carry secondary information on the characteristics of fluids such as densities, particle size distributions of the solids, and the types of materials used which make up the slurry. This secondary information manifests itself by having a distinctly identifiable frequency component and amplitude component. A low-cost spectrum analyzer is an effective method of extracting the frequency components. A peak detector based on comparators and A/D conversion principles was found to be adequate in extracting the amplitude component of the signals. Results obtained from the spectrum analyzer and the peak amplitude detector can then be related, digitally, to the density and other characteristics of slurries.