A study of the fluidization of FCC particles and nanoparticles in a rectangular bed and a riser

The speeds of motion of compression waves through a 3m tall fluidized bed of l0nm silica particles and 75 micron FCC particles were determined by measuring the times of arrival of compression zones using light and a gamma ray densitometer, respectively. A correlation for the solids stress modulus for each particle type was determined as a function of void fraction. Using kinetic theory type equations of state for particles, this experimentally determined wave velocity gives a value for the granular temperature for 10nm particles of approximately 1 m2/s2. The value of the granular temperature was also determined in a two-dimensional fluidized bed by measuring the volume fraction distributions of 10nm silica particles. Granular temperatures were deduced for a one dimensional particle momentum balance using an ideal equation of state for particles. These granular temperatures agreed with the measurements obtained from wave propagation experiments. Additionally, a solids volume fraction distribution map and the solids volume fraction measurement at the nanoparticle bed interface provided new insight into the solids volume fraction distribution within the rectangular bed.; The experimental results for the FCC and nanoparticles experiments are compared to simulation results. This research used the two fluid simulation model developed by Sun and Gidaspow. The relationship for the solids stress modulus developed in the experimental work was used as input to the simulation model. The FCC simulation results closely followed the experimental measurements. The nanoparticle simulations replicated several aspects but not all of the experimental measurements. The difference between the simulation results and the experimental results was attributed to the complex behavior of the agglomerates.