(127c) Gas Oil Flow in the Two-Stage Separator System in FCC Disengager

Without any simplification the full scale and three dimensional mathematical model of structured mesh was built according to the actual structure of disengager and the numerical simulation of the flow in FCC disengager was carried out by applying an advanced RNG k-ε Model and Eulerian multiphase model. Two diversion sections were installed on the primary cyclone's exhaust pipe, which has a rectangular cross section shape and points to the inlets of secondary cyclones. Detailed gas oil and catalyst distribution was obtained and the effect of the diversion section length on the gas oil flow behavior in the FCC disengager was analyzed. It was shown that the increasing diversion section length can dramatically reduce the quantity of gas oil to enter the disengagement space, effectively preventing the formation of coke in the separation system and FCC disengager shell and ensuring the normal and long period running of the FCCU.