Performance Analysis And Optimization Of Catalytic Cracking Cyclone Splitter

The heavy oil fluid catalytic cracking process is an important secondary processing process in the oil lightening process.It is the main method for converting heavy hydrocarbons such as vacuum gas oil into gasoline and light hydrocarbons.It is converted into light hydrocarbons such as gasoline that can be widely used in industrial production and social life.The core equipment that relies on this process is the fluid catalytic cracking(FCC)unit.The cyclone is the most important device in the catalytic cracking unit.The heavy oil is converted into light hydrocarbons in the riser in the fast splitter under the catalytic action of the catalyst particles,and the catalyst is under the action of the swirling head.Gas-solid separation can also be achieved.The performance of the cyclone is directly affected by the overall performance of the catalytic cracking unit.Therefore,analyzing its internal flow field and improving its structure has great economic significance for industrial production.In this paper,using CFD computational fluid dynamics software,based on the cyclone quick-distributor in a petrochemical cracking plant,the internal flow field is analyzed,and its structure is further optimized,which is the industry of the cyclone.The application provides a theoretical reference.The specific research contents are as follows:(1)this paper reviews the research on fast-dividers by domestic and foreign scholars,compares the advantages and disadvantages of inertial separators and centrifugal separators,and briefly introduces the significance of this research to enterprises.(2)The CFD software used in the simulation process is introduced,and the control equations used in the simulation calculation process are enumerated in detail.On the basis of the above,the gas phase simulation was carried out on the cyclone,and the fast-distributor was obtained by detecting the tracer content at the outlet by releasing the tracer at the inlet after the steady-state calculation and performing transient calculation.The gas residence time curve is analyzed;the gas-solid two-phase flow in the cyclone quick separator is analyzed by the combination of the hybrid model and the discrete phase model.(3)The gas flow field and the gas-solid two-phase flow field were analyzed.It was found that the swirling quick separator had insufficient structure in the part of the choke and the settling section.The specific performance was as follows:the length of the choke is too short,which is not enough for the jetting fluid.The current limiting is carried out;the gas phase and the solid phase velocity in the settling section are both low,and the low-speed spiral motion is performed,which increases the residence time of the catalyst particles and adversely affects the catalytic cracking.(4)The length of the choke is extended for the problems found and the dissipative plates are installed in the settling section.Through analysis,it is found that the structural improvement optimizes the internal flow field of the cyclone.Furthermore,the numerical simulation method is used to optimize the structure of the dissipative plate.The optimized structure includes length,width and the number of dissipative plates installed.