Apparatus for regeneration of hydrocarbon conversion catalyst

Apparatus for effecting regeneration of spent catalyst particles used in hydrocarbon conversion reactions having an arrangement that permits cooling and heating of the catalyst particles with a single air stream and one air heating zone, said apparatus comprising:

• (a) a vertically-positioned vessel through which catalyst particles may move by gravity, which vessel has a cylindrical upper section comprised of burn zone and a cylindrical lower section having a smaller diameter than said upper section and comprised of a catalyst drying zone, an air heating zone, a catalyst cooling zone, and a catalyst outlet nozzle located at the lower end of the lower section;
• (b) two vertical cylindrical catalyst retention screens having differing diameters which extend substantially throughout said vessel upper section, which are concentric with one another to form an annular volume through which a descending bed of catalyst may move by gravity, where said annular volume communicates with said catalyst drying zone in said vessel lower section, and which are concentrically disposed in said vessel upper section to form an annular space for distribution of gas between the vessel wall and a larger diametered of said two vertical cylindrical catalyst retention screens;
• (c) at least one spent catalyst inlet nozzle on said vessel and at least one internal catalyst inlet conduit which is connected to said catalyst inlet nozzle and communicates with a top portion of said annular volume formed by said catalyst retaining screens;
• (d) at least one recycle gas nozzle on said vessel which communicates with said annular gas distribution space;
• (e) at least one flue gas nozzle on said vessel which communicates with a cylindrical central space enclosed by said smaller diameter catalyst retention screen;
• (f) said catalyst drying zone, comprises the uppermost portion of sad vessel lower section and is in communication with said annular bed of catalyst;
• (g) said air heating zone, which is located immediately below said catalyst drying zone and comprises a plurality of heating elements passing through the center of said heating zone for heating an upward flowing stream air, at least on catalyst flow passage located about the periphery of said air heating zone and means for preventing contact between said heating elements and said catalyst particles;
• and,
• (h) said catalyst cooling zone, having an air inlet nozzle on said vessel, and having means for air distribution connected to said air inlet nozzle, which catalyst cooling zone is located immediately below said air heating zone, where said air distribution means is disposed in a horizontal plane located in a lower portion of the cooling zone such that air may be distributed in a substantially uniform manner over said horizontal plane.