MATHEMATICAL MODELLING OF A ROTARY SWIRL CYCLONE SCRUBBER

A Rotary Swirl Cyclone Scrubber (RSCS) is a device designed to remove SO2 and ash from the combustion products of an entrained-flow gasifier. It uses a combination of highly swirling flow and water sprays to produce high heat and mass transfer rates. In order to develop a better understanding of the operation of this device, modelling has been performed using an extended version of CFX-F3D. Simulations have been performed to examine the flowfield in the device and to determine SO2 and ash capture efficiencies. The simulations show that the water jets used to remove the SO2 from the gas completely change the direction or swirl in the device, resulting in a highly turbulent flow. The experimental SO2 capture efficiency and the outlet temperature are well reproduced using a water droplet size of 60 μm, with this value being determined via fitting to a particular experiment. Predictions of ash particle capture are found to be in good agreement with the experimental data.