Gain and time-constant variations in liquid-fluidized beds

Abstract

Expansion and contraction characteristics of liquid-fluidized beds, as reflected in the way bed height varies following stepwise increase or decrease in fluidizing velocity, were studied for a few different systems. The transient bed level data were converted to frequency response and, utilising a first-order transfer function model reported in the literature, the parameters of interest (namely, the time-constant and static gain) were evaluated. The results were used to differentiate the influence of experimental variables, such as particle size, bed height and step-flow disturbance, on bed level dynamics.