A light extinction-based concentration measurement in two phase gas-solid flow

•concentration measurement based on light extinction through a particulate flow.•global measurement of mean particle concentration.•particle concentration distribution in a round jet for varying Stokes number. Current methods of concentration measurements, such as laser Doppler anemometry (LDA)/phase Doppler anemometry (PDA), and planar nephelometry provide accurate local measurements of concentration but are expensive and complicated to set up and operate. Our concentration measurement method involves the measurement of light extinction through a two-phase flow and is based on well-established methods. The proposed configuration is comparatively inexpensive and easy to operate. It can also provide global measurements of mean particle concentration for axisymmetric distributions of particles. We validate the method by comparing the extinction efficiency measured with this method for a given particle size with the known value (of somewhat less than two) for a non-ideal imaging setup. We also use the technique to measure the concentration distribution in a round jet, and show that the results are similar to those measured by previous researchers using different measurement methods. Finally, we apply the method to show how the concentration distribution in a particulate jet varies with particle charging.