Numerical Simulation Of Flow Field In The New Types Of Towers With Sloping Plates For Wet Dedusting And Desulfurizing

The total suspended particulate(TSP) and sulfur dioxide are still the primary air pollutant of China in present period, and environment protection operators have done a lot of study to reduce and control the air pollutant. On the basis of systematically summarizing predecessors' work, Professor Li Caiting designed the new two types of towers for wet dedusting and hazardous gas removal, which were the tower with rectangle sloping plates and the tower with umbrella sloping plates. With the high efficiency of dust removing, simple and compact configuration , and low operating cost, the equipments has wide application in the future. In order to observe the distribution laws of the towers'flowfield, the gas-liquid two-phase flow in the two new types of towers was numerically simulated by using of CFD (computational fluid dynamics) software.The gas-phase simulation described with standard k-εturbulence model was adopted SIMPLE algorithm. In this paper, the gas flow for different models was simulated with the gas velocity of tower from 2 to 4m/s. The result showed that the sloping plates could intensify the gas disturbance and delay the gas residence time, which were good for dedusting and removing the hazardous gas; also, the gas impingement was observed on wall in the tower's region of inlet; the dead area can be effectively avoided in the cylinder towers with the central outlet.The gas-liquid two-fluid model combined with the kinetic theory of the particulate phase was built. In the model, the effect of particles on gas turbulence was taken into account and the source term of the gas k-εturbulence model was modified. The liquid wall behavior was described by wall-film model. The transient and steady simulation showed that the spray liquid droplets could played an intensive flow straightening role with regard to the gas flowfield; the suction of gas was observed in the region of nuzzles; when the gas velocity of the inlet was bigger, the volume percentage of liquid in the tower increased, and this may cause liquid entrainment.Finally, the test experiments were carried out and the results showed that the experimental data agreed well with the simulative data.