(411c) Gas Flow Behavior In FCC Disengagers Vessel with Different Outlet Tube Length of Primary Cyclone Separator

To deeply understand the effect of primary cyclone separator’s outlet tube length on gas oil flow behavior in fluid catalytic cracking disengager space, the gas oil flow in a full-size disengager is numerically studied on the platform of a commercial computational fluid dynamics (CFD) code Fluent 6.1.22. The Reynolds stress model (RSM) is applied to simulate the gas oil flow field. As no geometry simplification is made in generating the structured mesh for the space both inside and outside the two-stage separator system, the whole flow behavior of the gas oil in the disengager is obtained. Coupled with the RSM, the stochastic tracking mode is used to quantify the gas oil into the secondary cyclone separator. It is shown that the growth of the outlet tube length of primary cyclone separator contributed to oil gas flowing into the inlet of secondary cyclone separator, effectively reducing the gas oil quantity into the disengager and the gas oil residence time, which avoids unwanted overreaction of hydrocarbon.