Flow and Heat Transfer Characteristics of Liquid-Solid Circulating Fluidized Beds

A series of experiments was conducted to investigate the flow and heat transfer characteristics of liquid-solid circulating fluidized beds. The experimental apparatus consisted of a single riser and a downcomer. Water at ambient conditions was used as the fluidizing fluid. Six kinds of particles were tested. First, particle holdup was measured, and a set of systematic data was acquired. By analyzing the experimental data, a simple predicting correlation was derived for the particle holdup. Next, pressure drop measurement was performed, and a predicting correlation was derived. Then heat transfer coefficient was measured, where two regions were identified, i.e., the oheat transfer enhanced regiono and the oliquid single-phase heat transfer region.o On the basis of the experimental data, a predicting correlation was derived for each region, and a correlation was proposed for the entire region. Lastly, making use of the already-derived correlations, an analogy was investigated between the frictional pressure drop and the heat transfer coefficient.