The Study Of The Structure Effect On The Performances Of Square Cyclone

A series of experiments, which study the influence of structure parameter on the performance of the curved inlet square cyclone, have been conduced. The trend of the performance changing with structure parameter was concluded and the structure parameters were optimized. By numerical simulation of gas-solid flow field in square cyclone, the mechanism of the influence of structure parameter on the cyclone performance is explained. By observing the separating process of gas-solid flow in square cyclone, the separation characteristics of the square cyclone at high inlet solid concentration are acknowledged.In order to study the influence of structure parameters, such as the inlet height/width ratio, a/b, votex finder diameter, d, insert lengh of the votex finder, s, vertical height of square section column, h, on the cyclone performance, 42 cyclones with different structure parameters were designed. For these 42 cyclones, the width of the square section, D is kept as constant as 300mm, other parameters ,a/b,d,s and h ranges from 3.8 to 10.56, 0.27D to 0.5D, 0.5D to 0.7D and 1.8D to 2.8D, respectively. On a cold apparatus, 27 cyclones were based on orthogonal design chosen and the efficiencies were measured under the same operating condition. The results showed that the influence of the different parameters on the separation efficiency of square cylone downgrades from a/b, h, d to s, and there exist intensive interaction between a/b and h, the optimized value of d and s are 0.4D and 0.6D. For further research on the influence of the structure paramers a/b and h on the performance of square cyclone, the separation efficiency and pressure drop of 15 cyclones with different a/b and h were tested under the same operation condition, which found how the 2 parameters influence the performance of square cyclone. The optimized values of a/b is 8, and h is 1.8D.The gas flow field of 5 square cyclones with different a/b and h wassimulated using Renolds stress model(RSM). The tracks of different diameter particles in square cyclone were simulated using stochastic model. Through analyzing the flow fied and the tracks of particle, the machnism of a/b and h on the performance of square cyclone is achnowledged.The separation process of gas-solid in square cyclone with high inlet solid concentration was observed at a stable operating condition. Most coarse particles are separated by the effect of inertia force when entering square cyclone, and fall down along the coner of cyclone. Only few fine paricles that carried by gas flow enter the separation space in square cyclone and are separated by the effect of cetrifugal force. Particle agglomeration and entrain effect of coarse paticle on fine particle are the main reason for the influence of solid concentration on the separation efficiency. The separation of fine particle in separation space determines the sepatation efficiency of square cyclone.