Numerical Simulation Of Flow Field And Research Of Design Optimization In Cyclone Separator Used In FCCU Unit

With the rapid development of industry, agriculture, transportation and other sectors of the defense industry, the demand and product quality requirements of light oil are increasing daily. FCCU is an important kind of heavy weight reduction process to improve the refinery crude oil processing depth, to produce high-octane gasoline. In the FCCU unit, an important device is the cyclone separator. It is used in the FCCU to separate oil-gas and catalyst and the catalyst is recovered to provide recycling, it also makes sure that the subsequent step is normal.For the study of the cyclone separator in the past, we focused on the theoretical and experimental methods, however, experimental methods combining theory relatively take long time. In recent years, with the development of computational fluid dynamics, and on the basis of theoretical analysis and experimental research, through the computer simulation to achieve the internal flow details in the cyclone and optimal design of the structure has an important value.In this paper, use a kind of CFD software to simulate the internal flow field in the cyclone separator, in-depth understanding of the internal cyclone gas flow field characteristics and solid flow field characteristic to simulate the separation efficiency and pressure loss and other properties of particles under different conditions, consider the impact of operating parameters and structure parameters on cyclone performance, and to optimize the design of the structure, in order to obtain a high separation efficiency and low pressure drop loss structure in a suitable working condition.First, the RSM turbulence model of gas flow field in a cyclone within the numerical simulation results showed double swirl in the internal flow, then we analysis the cyclone turbulent kinetic energy distribution and pressure distribution further.Secondly, based on gas flow field research and with the use of DPM model, we simulate the track of the particles in the cyclone, in-depth study of the movement of gas-solid flow. And draw a conclusion that small particles have a small rotation pitch and great randomness, large diameter particles, the rotation pitch is large, will soon be captured. Incident from different position, the lower end of the incident particle is not likely to be captured.Finally, Research the impact of inlet velocity and particle diameter on separation property. Analyze separation property of special cyclone separator which has a volute-type entrance and which has a tapered exhaust pipe. And the relationship between various parameters mentioned before. The cyclone which has a diameter of 300 mm exhaust pipe, has the highest separation efficiency, belonging to the optimal structure.