Process for cooling during regeneration of fluid cracking catalyst

Claim 1

A process for regeneration of coke contaminated fluid cracking catalyst comprising in combination the steps of: A. maintaining a dense fluid bed of hot catalyst in a regeneration zone at a temperature in the range of 649° C. to 787° C. (1200° F. to 1450° F.), providing an oxygen containing regeneration gas injection point within said dense fluid bed and passing coke contaminated catalyst into said dense fluid bed at a point above the said regeneration gas injection point; B. withdrawing a controlled stream of said catalyst from said dense fluid bed at a point above said regeneration gas injection point and passing said stream through a downflow indirect heat exchange zone to cool said catalyst; C. passing cooled catalyst now at a temperature in the range of 593° C. to 704° C. (1100° F. to 1300° F.) to the bottom of a gas lift zone located in approximately the same horizontal plane as said heat exchange zone; D. passing the cooled catalyst by vertical accelerated gas drive upwardly through the gas lift zone at a velocity of 15 to 30 feet per second by employing a lift gas separate from regeneration gas; and E. lifting a controlled quantity of cooled catalyst up into the dense bed of hot catalyst in said regeneration zone, above the said regeneration gas injection point whereby hot catalyst is cooled by mixing with the cooled catalyst.