Research On The Jet Stirring Dynamics Of Lime Slurry Pond Of Wet Flue Gas Desulfurization System

The coal plays the most important role in electric power industry in China in present. SO2 pollution problems should be paid attention based on the above fact. Wet flue gas desulfurization system dominates in the absorption of SO2 in the coal-fired plants, and the desulfurization of limestone/gypsum is widely used in the area. Mixing equipment should perform well in order to fully absorb the SO2, but the cost heavy, leakage and security risks are appeared easily in fact. The rotary jet mixing system is introduced into the area to overcome the disadvantages of traditional mixing equipment.Based on the previous work, the paper focuses on the appliance of rotary jet mixing system in SO2absorption. The geometry model is based on Pucheng 600MW slurry pond, and the simulation focuses on the influences of the changes of angular velocity and jet velocity on flow field. And the two-phase results would be compared to the three-phase to explore the influences to flow field because of the appearance of the new phase.In gas-liquid condition, the simulation shows that oxidation air distribution relies on the distributed velocity and the Z velocity near the tank wall. Oxidation air distribution tends to worsening after a good start along with the changes of angular velocity. Oxidation air distribution tends to be good along with the changes of jet velocity. But continued optimization is not obvious while jet velocity is faster than 50m/s.In liquid-solid condition, limestone particle concentration shows a decreasing trend with the increase of the rotation angular velocity. It is the results of mixing inadequate for mixing slurry and pure slurry while the distributed velocity tends to reduce after a increasing start. And the jet length tends to increase with the increase of jet velocity. Base on the fact, the distributed velocity shows to increase at the beginning, but the rate of increase is not obvious when velocity is high. It is obvious that the down-stream is more important than the distributed stream in liquid-solid condition.Compared the gas-liquid/liquid-solid condition with gas-liquid-solid condition, air VOF in gas-liquid-solid condition is higher than the gas-liquid condition. It is the results that the distributed velocity tends to gentle because of the appearance of the solid phase, and the down-stream plays an important role in air lateral distribution. And limestone particle concentration in liquid-solid condition is higher the gas-liquid-solid condition. The reason is that the distributed velocity near the wall is lower and the Z velocity is higher than the liquid-solid condition when the down-stream velocity is equal. For the reason, it is easy to know that limestone particle concentration in gas-liquid-solid condition is lower than the liquid-solid condition.