A NEW IMAGE-BASED METHOD TO MEASURE SOLIDS HOLDUP AND CLUSTERS IN A NARROW RECTANGULAR CFB

摘要

A newly developed method based on a calibration correlating the solids holdup and image grayscale has been developed in the fully developed region in a rectangular Plexiglas CFB riser using a high-speed video camera.FCC particles 67 μm with particle density of 1880 kg/m3 were used as the bed materials.Using this method, the lateral distribution of solids holdup can be obtained.Comparing with that obtained by the optical fiber probe, the similarities verified the feasibility and accuracy of the image-based method.This method was then used to transform the original grayscale image into the binary image, clusters with clear shape and boundary can be visualized.With the area of the cluster calculated by the number of pixels occupied by the cluster image, the cluster equivalent diameter can be determined.Meanwhile, the solids holdup inside the clusters can be obtained by the image arithmetic operation in combination with the calibration equation.