| 摘要 |
<p>A fluid catalytic cracking unit (FCCU) comprises a uniquely shaped conduit between the primary and secondary cyclones or, in the alternative, between the riser and the primary cyclone, which creates an increase in the suction of the dilute phase vapour beyond that normally available in the reactor vessel, thereby reducing the dilute phase residence time in the vessel, reducing post-riser thermal cracking, hydrogen transfer reactions, and coking tendency of mixture in dilute phase. <IMAGE></p> |
