Fluid catalytic cracking apparatus having riser reactor and improved means associated with the riser reactor for separating cracked product and entrained particulate catalyst

In an apparatus for fluidized catalytic cracking of hydrocarbon feedstocks, the improvement comprising the combination of an ascending riser reactor having its upper end opening into a separator vessel and means at its lower end for introduction of hydrocarbon feedstock and particulate catalyst, flow reversal means at the upper end of said riser reactor and an attached downwardly directed flow reversal conduit the lower end of which opens into said separator vessel for directing the flow of cracked hydrocarbon product and entrained particulate catalyst downwardly toward said separator vessel, a catalyst stripper located at the bottom of said vessel, and cyclone separator means having gas inlet duct means which are in communication through the wall of said flow reversal conduit with the interior thereof, said cyclone separator means being connected to said separator vessel so as to vent said cracked hydrocarbon products outside of said separator vessel.