无沉降器催化裂化装置的设想

A FLUID CATALYTIC CRACKING PROCESS WITHOUT DISENGAGER

对于分子筛催化裂化工艺而言,催化裂化装置沉降器的作用仅是包容旋风分离器和用于待生催化剂的沉降和保温。但沉降器存在的大空间却形成了油气的滞留空间,油气流速低,停留时间长,结果导致反应油气的二次裂化反应,油气中的液滴和催化剂颗粒易于沉积在沉降器器壁上结焦形成焦块。因此,提出了取消沉降器,采用无沉降器催化裂化工艺装置的设想。该设想包括两个方案,第一个方案为:封闭式旋流快分器作为第一级分离器,多个并联PV型旋风分离器作为第二级分离器,旋风分离器的料腿出口阀采用气动V型阀;第二个方案为:带汽提器的旋风分离器作为第一级分离器,多个并联PV型旋风分离器作为第二级分离器,旋风分离器的料腿出口阀采用翼阀。

The disengager no longer works as a reactor in the FCC unit as it did in the early days. It now becomes a vessel to house the cyclone and provide space for maintaining pressure and temperature of settling spent catalyst. As disengager contains a large volumne space in which the oil vapor flows at lower velocity and resides for a longer time, the over-cracking of oil vapor occurs and the liquid droplets in oil vapor and catalyst particles tend to deposit on the internal wall of disengager to form coke. Fluid catalytic cracking （FCC） process without disengager is proposed based on the FCC development and evolution of the reactor＇ s function. Two processes are recommended. One uses closed vortex separator as 1st stage cyclone, multiple PV type cylone separators as 2nd stage cylone and pneumatic V type valve for the outlet valve of dipleg of cyclones, and other one applies stripping type cyclone separator for the 1 st-stage cyclone, multiple parallel PV type cyclone separators for the 2nd-stage cyclone and wing type valve for the outlet valve of dipleg of cyclones.