LDV measurements and analysis of gas and particulate phase velocity profiles in a vertical jet plume in a 2D bubbling fluidized bed Part III: The effect of fluidization

摘要

In the present work, the effect of emulsion fluidization on the gas and particle phase transport in a highspeed gas jet plume in a bubbling bed is examined. Implementing a Laser Doppler Velocimetry (LDV) technique, the gas and particulate phase velocities of a gas jet injected into a bubbling bed of 838 μm high-density polyethylene (HDPE) micropellets were measured. These velocity profiles were used to determine the volume fraction, mass flow, and momentum transport rate for each phase at various axial locations as well as an average particle drag coefficient in the measurement region of the plume. Maintaining consistent gas jet inlet conditions, the HDPE emulsion fluidization was varied from a spouted bed to 50% beyond minimum fluidization. In addition to the integral flow values, centerline phase velocity scaling is also examined. The scaling is based on the development of similarity velocity profiles for the two phases. Additional experiments to investigate this idea were carried out with 1) the particle emulsion and fluidization level is held constant while the jet inlet velocity is varied and 2) the jet inlet velocity and fluidization ratio is held constant while the bed particles are varied.