Canadian Journal of Chemical Engineering, Vol.96, No.5, 1109-1115, 2018
Fluidization characterization of nano-powders in the presence of electrical field
Alternating electric field was used as an external assistance method to enhance the quality of fluidization of nanoparticles. The electric field was applied to the bed using two parallel electrodes, one grounded and AC voltage applied to the other. Varying electric field strength in the range of 0-1kV/cm was used in the experiments. Hydrophilic TiO2 nanopowder was used as the bed material. The bed was fluidized with either pure nitrogen or nitrogen containing isopropanol vapour. It was found that increasing the alternating electric field strength decreases the minimum fluidization velocity, bubble size, and agglomerate size. Adding isopropanol vapour to the fluidizing gas decreases the minimum fluidization velocity, bubble size, and agglomerate size, compared to fluidization with dry nitrogen, at the same field strength. It is shown that increasing the alternating electric field strength increases the voidage of the bed at minimum fluidization and decreases the voidage of agglomerates.