Heat Transfer Characteristics and Particle Behavior Around a Horizontal Heating Surface Immersed in a Sound Assisted Fluidized Bed of Fine Powders

In the last fifty years, fluidization has progressed through systemic research, with various specialized functions such as combustion, mixing, chemical reactions, heat and mass transfer, coating, granulation processes. This research development persuaded the researchers to become interested in the use of fine cohesive powders. Many industrial processes require the use of fine powders in the manufacture of catalysts for reactors, ceramics, pharmaceuticals, paints and cosmetics. Fine powders belonging to Geldart group C particles are difficult to fluidize mainly because of cohesiveness. Studies related to heat transfer in a sound assisted fluidized bed of fine powders (Geldart Group C and Group A) are very limited. In this paper, heat transfer in a bubbling fluidized bed of fine powders and immersed heating surface in absence and presence of acoustic waves is investigated. The experiments were carried out to measure surface temperatures, local heat transfer coefficients and average heat transfer coefficients at various fluidization velocities at different positions on heat transfer tube and with different materials. It can be concluded that acoustic energy of sufficient intensity and sound pressure level improves the quality of fluidization.