Intensification of liquid mixing and local turbulence using a fractal
injector with staggered conformation
Abstract
Two self-similar, tree-like injectors of the same fractal dimension are
compared, demonstrating that other geometric parameters besides
dimension play a crucial role in determining mixing performance. In one
injector, when viewed from the top, the conformation of branches is
eclipsed; in the other one, it is staggered. The flow field and the
fractal injector induced mixing performance are investigated through
computational fluid dynamics (CFD) simulations. The finite rate/eddy
dissipation model (FR/EDM) is modified for fast liquid-phase reactions
involving local micromixing. Under the same operating conditions, flow
field uniformity and micromixing are improved when a staggered fractal
injector is used. This is because of enhanced jet entrainment and local
turbulence around the spatially distributed nozzles. Compared with a
traditional double-ring sparger, a larger reaction region volume and
lower micromixing time are obtained with fractal injectors. Local
turbulence around the spatially distributed nozzles in fractal injectors
improves reaction efficiency.