Vented stripper section for a fluid catalytic cracking unit apparatus

摘要

Disclosed is a process and apparatus for fluid catalytic cracking (FCC). Output of an FCC riser feeds a riser cyclone. A downstream end of the riser and the riser cyclone are located within a reactor vessel (disengaging vessel) having sidewalls. Cracked hydrocarbons in the output pass from the riser into a riser cyclone and discharge from the reactor vessel without being added to a reactor vessel atmosphere. A stripper cap divides the reactor vessel atmosphere into upper and lower portions. The stripper cap and a lower portion of the reactor vessel sidewalls define a stripping zone. A riser cyclone dipleg extends through an opening in the stripper cap into the stripping zone. A chimney vent conduit is provided for conducting stripped hydrocarbons out of the stripping zone without being added to the atmosphere of the reactor vessel above the stripper cap.