Particles Mixing in a Fluidized Bed by Using Digital Image Processing and Thief Probe

Particle size plays a major role in segregation phenomena in mixing process. In pharmaceutical industry, it is essential to have a proper analysis to make sure that the good product is well mixed and to prevent segregation. In this study, Digital Image processing has been used as an alternative method to thief probe, to study the effect of particle size on mixing and segregation process. The experiment started with execution of image acquisition process of mixing process. The images taken were further analyzed using Image Processing Tool in MATLAB software. The experiments were done with two different arrangement of particle in the bed using air velocity of 0.94 ms⁻¹. The mixture was considered to be well mixed when the intensity of red of colour histogram is approximately constant. For the layered position, the good mixing time for set 1, 2, 3 and 4 were achieved at 62, 84, 86 and 74 s respectively. Then, for random position, homogeneous mixture were achieved at 62, 76, 82 and 72 s for set 1, 2, 3 and 4 respectively. This finding has been quantified by using Lacey Mixing Index where the value obtained was nearly to 1.0 which showed uniform mixing.