Fluid catalytic cracking apparatus having riser reactor and improved

Abstract

An apparatus for the fluid catalytic cracking of hydrocarbons having a riser reactor with structure at its lower end for introduction of hydrocarbon feedstock and particulate catalyst and having its upper end opening into a separator vessel. A flow reversal structure attached to a downwardly directed flow reversal conduit is provided at the upper end of the riser and within the separator vessel. The flow reversal structure and conduit serve to direct cracked hydrocarbon products and particulate catalyst downwardly toward a stripper located at the bottom of the separator vessel. Cyclones having gas inlet ducts in communication through the wall of the flow reversal conduit are provided. The cyclones are connected to vent cracked hydrocarbon products outside of the separator vessel.