Apparatus for regenerating cracking catalyst

Claim 1

In a fluid catalytic cracking apparatus comprising a reactor vessel and a regenerator vessel, said reactor vessel comprising a reactor riser means and a separation means for separating products of a catalytic cracking reaction from spent catalyst, said regenerator vessel comprising a bed of spent catalyst, placed substantially in the center of said regenerator vessel, and a bed of regenerated catalyst, placed substantially concentrically about said bed of spent catalyst, a means of recycling at least a portion of said regenerated catalyst from said regenerated catalyst bed to said spent catalyst bed and a regenerating medium inlet conduit cooperating with a regenerating medium distribution means in the lower section of said spent catalyst bed, the improvement wherein: said bed of spent catalyst is substantially completely separated from said bed of regenerated catalyst by a substantially annular wall means, said bed of spent catalyst further comprises a riser in the upflow section of said bed of spent catalyst said means of recycling at least a portion of said regenerated catalyst from said regenerated catalyst bed to said spent catalyst bed comprises at least one trickle valve means placed in said annular wall means.