催化裂化装置旋风分离器的料腿排料是一个负压差排料过程,内部的颗粒需要从高处的低压区流向下部的高压区,此时需要借助于内部密相料柱的蓄压平衡外部的负压差保证排料。针对催化裂化装置再生器内两级串联旋风分离器料腿的不同安装结构形式,即第一级料腿插入密相床层,第二级料腿出口联接翼阀或插入密相床层或悬挂于稀相床层的情况,推导出了第一级料腿和第二级料腿的负压差和蓄压计算方法,并分析了形成排料的条件。计算分析表明,第一级料腿的负压差主要是第一级料腿插入密相床的深度压差和第一级旋风分离器的压力降之和,第二级料腿的负压差则主要为两级旋风分离器的压力降之和,第二级料腿的负压差大于第一级料腿的负压差。料腿的排料条件是料腿内部的蓄压大于等于其外部的负压差。
The cyclone dipleg discharge process in FCCU is a process under the negative pressure difference. The particles have to flow down the dipleg from the top region with low pressure to the bottom re- gion with high pressure. Therefore, the particles in the dipleg are accumulated to form a stock column to bal- ance the negative pressure and maintain discharge. The calculation method of negative pressure and accumula- ting pressure is derived for two stage cyclone diplegs in series collection in the FCC regenerator, in which two forms of installation of dipleg are considered, namely, the 1 st-stage dipleg submerging into the dense-phase bed, the 2nd-stage dipleg fitted with a trickle valve submerging into the dense-phase bed or suspending in the dilute phase bed. Also, the discharge condition for dipleg of each stage is analyzed. The calculation and anal- ysis show that the negative pressure difference of 1 st-stage dipleg is mainly the sum of the dipleg insertion depth pressure difference into the dense phase bed and the pressure drop of 1 st-stage cyclone separator. How- ever, the negative pressure difference of 2rid-stage dipleg is mainly the sum of pressure drop of two-stage cyclone separators. The negative pressure difference of 2nd-stage dipleg is greater than that of 1 st-stage dipleg. The discharge condition is that the accumulating pressure within the dipleg is greater than or equal to its external negative pressure difference.