GB590868A - Improved apparatus for stripping volatile material from solid particles - Google Patents

Abstract

In apparatus for contacting a fluid and a fluidized solid (e.g in the catalytic cracking of hydrocarbons), of the kind in which solid is withdrawn continuously and stripped of absorbed fluid, a conical inlet member 16 having a perforated top plate 17 is arranged in the bottom portion of a vessel 10, and a vertical sleeve 38 is secured to the periphery of the plate 17, extends above and below the plate, and is spaced from the inner wall of the vessel to provide an annular space 36 into which stripping gas is introduced through lines 40, 41. Preferably the annular space is divided by vertical partitions into long narrow parallel sections each with a separate inlet line for the stripping gas. In order to prevent the stripped solid from remaining too long in the lower part of the vessel, a second conical member 46 may be attached to the sleeve, and gas may be introduced through line 52 to prevent accumulation <PICT:0590868/III/1> of particles in the space 77 between the conical members. Serrations may be provided at 78 and and 84 to ensure an even flow of gas. In the catalytic cracking of a hydrocarbon oil carried out at 800 DEG -1000 DEG F. with a catalyst to oil ratio of 5/1 to 30/1 , the spent catalyst is stripped with steam at 350 DEG F. passing upwardly at 1.4 feet per second.