The Performance Research About The New Type Dry-process Predecomposition System

Two-phase flow in cyclone preheater group and decomposing furnace was simulated by CFD software in this paper. On the base of deeply understanding of the structure of preheater cyclone , decomposing furnace and the single-phase flow field in them, dose the research for the flow of gas, moving tracks of particles, pressure drop and separated efficiency in many different conditions.For the following works on this thesis: First, through compared two models of turbulence, standard k-εand RSM, as well as several format of pressure interpolation and difference scheme, the method of numerical computation for simulating preheater cyclone has been confirmed; at the same time, the appropriate model of two-phase flow for preheater cyclone system has been confirmed also. Second, the single-phase flow behavior of preheater cyclone system has been analyzed, including the velocity of inlet, pressure distributing, characteristic of onflow and its influence about separated efficiency. Third, the relation between the parameter of structure and operation and working performance has been analyzed, including the velocity of inlet, diameter of the exhaust duct, diameter of the granule, air leak of the system.Basis on the result of research, there were come to some conclusions: First, in order to get more ideal results, we must adopt Reynolds Stress Model based on anisotropy, SIMPLE format on the premise of good mesh for the simulation of the complex flow field in preheater cyclone and decomposing furnace system. Second, the main flow in preheater cyclone is double vortex, outside of which is the revolved flow downwards, center of which is the revolved flow upwards; low-pressure area distributing along the axes, the lowest pressure area lies in the area nearby the bottom of the exhaust duct, there also has some small backset. Third, with the accretion of the inlet velocity, the separated efficiency is much higher, but the pressure drop is also much higher; the diameter of exhaust duct has the same effect, with the accretion of the diameter of exhaust duct, the pressure drop is much higher, but separated efficiency is also much higher. Fourth, air leak of the system plays a serious effect with separated efficiency. Quantitative air leak can reduce the resistance but arouse much higher debasement of the separated efficiency, so we must avoid air leak of the system in the production.