Numerical Simulation And Performance Analysis Of Gas-Solid Two Phase Flow In Cyclone Separator

Recently, along with the enhancement of people's environmental protection consciousness, the cyclone separator as the representative of all kinds of dust catchers has become the main force of air pollution prevention. It plays an important part in eliminating air pollution, safeguarding human being's health and environment. It has been widely used in gas purifying, solid recycling and environment protection. The study on performance of cyclone separator by experiment takes not only a long period but also expensive charge. At present, the investigation emphasis of cyclone separator has turned from the whole characteristics to flow details. And computer simulation technology has been used to settle the problem.The computational fluid dynamics has been used in this thesis. Based on the investigation of cyclone separator, gas flow, gas-solid two phase flow, particle movement track, and separation performance have been simulated.First, the RNG k ?εturbulence model is adopted to describe the gas phase. The mainstream is double vortexes in the cyclone separator. And the two have the same rotation direction. Tangential and axial velocities are much larger than the radial velocity. The tangential velocity plays a dominant part of the three. Moreover, the orderliness of pressure distribution and the relationship between flux and pressure loss have been analyzed.Next, considering double coupling, the RNG k -εturbulence model in Euler coordinate system is adopted to describe the gas phase and the particle stochastic trajectory model in Lagrange coordinate system to describe the solid phase. The movement of single particle and particle group under different diameters at different intake positions has been presented. Results indicate that small particles are influenced by flow prominently and the random is very strong. However, great particles are influenced by flow slightly. Different intake positions can produce different phenomena such as top ash ring, vent-pipe short circuit and particle trap return mixing. When the particle groups enter from the middle part of the entrance surface, the separation efficiency is higher at the same conditions.Finally, it has been analyzed the influence of the manipulation parameters such as flux, particle diameter, particle thickness and structure parameters such as vent-pipe diameter, vent-pipe offset direction, relative eccentric distance to the separation efficiency. Based on the analysis, a structure-ameliorated cyclone separator has been brought forward and compared with the ordinary cyclone separator. The results indicate that its synthetical performance improves greatly.Thus it can be seen,by numerical simulation the flow orderliness in cyclone separator has been studied. The results have reference value to the design and structure optimization of cyclone separator.