Characteristics of Liquid Phase Backmixing in Gas–Liquid–Solid Mini-Fluidized Beds with Varied Pressure and Temperature

The gas–liquid–solid mini-fluidized bed
is a novel
multiphase reactor. It is important to comprehend how the behavior
of liquid phase backmixing changes with temperature and pressure,
which affects reactor design, scale-up, and optimal operation and
control. This study experimentally evaluates the residence time distribution
(RTD) of the liquid phase in a 10 mm diameter gas–liquid–solid
mini-fluidized bed using the pulsed tracer method. The findings indicate
that the backmixing reduces as the static bed height, liquid surface
viscosity, and pressure drop as the liquid velocity, system temperature,
and particle size rise. As the gas velocity increases, the liquid
backmixing initially drops and then increases, and the ideal operating
gas velocity is 21 mm/s. The RTD of the liquid phase in the fluidized
bed under small bed diameter conditions is also examined. The Peclet
number under 3 mm bed diameter conditions is substantially greater
than those under other situations, which is near the plug flow.