Numerical Simulation Of New Dust Removal Device For Quick Lime Slaking

Numerical simulation of the internal flow field in a new wet dust removal device for quick lime slaking was studied by computational fluid dynamics software FLUENT, based on the mechanical theory of the multi-phase flow, which provided a theoretical basis and technical support for the further optimization design of dust removal device for quick lime slaking.In the simulation of single-phase flow aspect , the SIMPLE algorithm and RNG k-εturbulence model were used. By comparing the flow field in the removal device under different outlet structures and different gas velocities, it was drawn that dedusting effect was best when gas velocity was 15m/s and tangential outlet was adopted. The distribution feature of the velocity field inside the device was also analysed from the tangential, axial and radial aspects in this condition. The turbulent kinetic energy was high near the center, which reduced with the height increasing, in the height of 500 mm, turbulent kinetic energy was the highest.In the two-phase flow aspect, based on the simulation results of single-phase flow, the injections were created by discrete phase model (DPM) to track and simulate.The results showed that the injection form of particles would affect the collection efficiency, when the solid particle size was greater than 30μm, and they could be all removed.The internal flow field had an obvious change after adding sprinkler and coupling with the gas, the velocity distribution of central gas was more uniform.With three nozzles spraying, the coverage area of mist droplets was largest, which kept dust particles and droplets contact fully and extend the residence time of gas flow in the device, so it was beneficial to improve the efficiency of dust collection. It would affect the flow field that nozzles set at different heights, The lower height would destroy the the swirl motion at the bottom, and the higher height would lead to the serious phenomenon of gas carrying water.