Research On The Physical Design And Structural Optimum Of Cyclone Separator In The Catalytic Cracking Unit

Cyclone separator is one of the most important regenerating devices for refinery catalytic cracking. Cyclone separation efficiency is generally low in practice and a large amount of catalyst is required in the catalytic process. It is easier for cyclone separator to collect catalyst of larger particles while the smaller ones are wasted so that resources are wasted and the environment is polluted.In this paper, CFD software is used to study the gas-solid flow of movement within the cyclone, and the basic model structure and parameter optimization is conducted, based on the cyclone separator of some plant’s catalytic cracking device and two performance indices separating efficiency and pressure drop focused on.In order to accurately predict gas flow field inside the cyclone, different turbulence models are used and the results were analyzed comparing with former LAD test. Finally, the RSM turbulence models are adopted. Because of dilute phase particles, the stochastic model(DPM) model is the best selection.Method determined, cyclone initial model simulation analysis is conducted to study speed field, the particle trajectories, particle sizing efficiency, overall efficiency and pressure drop etc. Result shows that gas movement is not uniformed that the outer air moves downwards while the inner goes towards the opposite direction with the same swirling style.By analyzing the velocity vector, “shunting” and “wagging tail” effects are adverse. The initial model of the separation of fine particles is weak in separation and the large ones are also need to improve. To ensure the accuracy of the calculation, convergence judgment based on residual convergence curve, the pressure coefficient curve, the overall mass flow rate is concerned.Based on the former research, much is done to deal with low separating efficiency of research on the optimization of entrance form, the main diameter, the diameter of the exhaust port, exhaust dust inlet diameter, cylindrical segment length, inlet angle, the length of the exhaust port, the cone angle, anti-back-mixing cone vertex angle. In order to reduce the amount of calculation, considering so many variations, two orthogonal experiments are used to obtained preferred configuration and the black struggle is installed and besides the anti-back-mixing cone position has been optimized.By analysis the former and the latter optimization model, results show that the optimized model has a better separation performance and pressure drop in the initial model and selecting the appropriate operating parameters, ultimately achieving the purpose of the resistance reduction efficiency.