Quantitative measurement of segregation phenomena in a binary-mixture fluidized bed by neutron radiography

Owing to a wide variety in fluidization properties of particles, segregation phenomena are hardly avoided in industrial fluidized-bed facilities. For the stability and controllability in the operation of such fluidized-beds, understanding of the relevant mechanism of particulate segregation is indispensable. Many factors, such as the difference in particle size, density, shape, and also arrangement of distributors, can be pointed out as the dominant causes for the segregation. Thus, any marking of particles for quantitative measurement may severely influence the segregation characteristic to be measured. But neutron radiography can be used for the quantitative measurement without disturbing the segregation characteristic. For estimating the segregation phenomena, evaluations of the particle fraction and the void fraction are required. For this purpose, two types of radiographies, i.e., X-ray and neutron radiographies were used in this investigation. Experimental results demonstrated the high performance of this method in investigating of segregation phenomena.