A fluidized catalytic cracking reactor vessel having at its upper end
means to separate catalyst particles from an effluent of a dilute phase
fluidized catalytic cracking reactor riser, which separation means are
fluidly connected to the downstream part of the reactor riser, fluidly
connected with means to discharge the cleaned reactor riser effluent from
the vessel and fluidly connected to means to discharge the separated
catalyst to the lower end of the vessel, the vessel further having at its
lower end means to discharge catalyst from the reactor vessel, wherein
(a) between the side wall of the vessel and the separation means a shield
is present, resulting in an exterior space between the vessel wall and
the shield and an interior space within the shield, wherein the interior
space is in open communication with the lower end of the reactor vessel
at its lower end and wherein the exterior space and interior space are
fluidly connected by means of one or more openings; and (b) means are
present to supply a gas poor in coke precursors to the exterior space.