带隔流筒旋流快分系统新型工业催化裂化沉降器内气相流场的数值模拟

采用RNG k-e湍流模型模拟带隔流筒旋流快分系统工业催化裂化沉降器内的气相流场，基于沉降器内气相流场的分析，考察了压力平衡管截面尺寸及封闭罩直径对封闭罩内外气量分配的影响. 结果表明，进入封闭罩外的汽提油气量随平衡管截面边长增加而增大，随封闭罩直径增加而减小. 封闭罩阻止了分离系统内油气进入沉降器中. 压力平衡管通过抽吸作用将封闭罩外的汽提油气快速引出沉降器，使封闭罩外的汽提油气在沉降器内的总停留时间降至13 s以下. 平衡管截面边长小于310 mm时，汽提气的引出分为两路；平衡管截面边长大于310 mm时，汽提气全部进入封闭罩外部，且分离系统内的少量油气向下流出分离系统至沉降器内. 封闭罩直径为3.8 m时，99%以上的油气都进入封闭罩外部.

Numerical Simulation of Gas Phase Flow Field in a Novel FCC Disengager

To obtain the flow details of gas phase, a three-dimensional numerical simulation of a novel industrial FCC disengager with flow partition cylinder quick separation system was conducted with RNG k-e turbulent model. The size of pressure balance tubes and the diameter of closing cylinder were mainly studied. The results show that the volumetric flow rate of stripping gas flowing into the exterior space of flow partition cylinder increases with increasing of balance tube size and decreasing of closing cylinder diameter. Closing cylinder prevents the oil gas from running into the disengager. The pressure balance tubes can accomplish the quick drawing-out of oil gas from the disengager by suction effect and make the oil gas total residence time fall to below 13 s. The extraction of stripping gas can be divided into two parts when the side length of pressure balance tubes is less than 310 mm, while the side length of which is more than 310 mm, a handful of oil gas will flow out of the separation system. When the diameter of closing cylinder is 3.8 m, more than 99% of stripping gas flows into the exterior space of closing cylinder.