Numerical Simulation of Inlet Duct Geometry Influence in Highly Laden Cyclones
Sprache des Vortragstitels:
In highly laden gas cyclones a particle strand is formed at the outer wall that is responsible for most of the overall particle separation. It is known from experiments that the inlet duct geometry can significantly influence the formation of this particle strand and thus the performance of the whole cyclone. Eventually, the separation efficiency can be improved by a favourable pre-formation of the particle strand in the inlet duct region
In this paper two inlet duct geometries comprising an inwardly and an outwardly orientated bend are considered in combination with a high throughput cyclone. The influence of the different inlet duct geometries is studied by means of numerical simulations and results are compared to experimental results found in literature.
For the two-phase simulation, a combined Euler-Euler granular and Euler-Lagrange approach is used. While the particle strand is governed by continuous kinetic theory based transport equations the particles in the dilute inner region of the cyclone are traced in a Lagrangian frame of reference. The combination of the two well known models is organized in four steps. First, based on a mono-disperse Euler-Euler granular simulation a free shear layer of the particle strand is identified. Next, distinct poly-disperse particles are emitted into the dilute surroundings. Those particles are traced until they escape by the cyclone outlet or re-enter the particle strand.