| 摘要 |
A mixture of shaped, catalyst particles comprising generally cylindrical, free flowing catalyst particles having substantially the same diameter and of varying length are length graded into a first group of particles having a length below a predetermined length, L1, said length L1 being in the range of from 0.8 to about 24 millimeters and at a value of L/D greater than one, and a second group of particles having a length greater than L1, by: feeding the catalyst mixture into a cylindrical drum having inwardly opening indentations in a cylindrical wall thereof, the indentions having a transverse diameter of substantially L1; rotating the drum about a longitudinal axis thereof at a speed sufficient entrap in the indentations and convey the particles having a length below L1 and comprising the first group upwardly to a height permitting the particles to fall into a fixed, upwardly opening trough, while retaining particles having a length above L1 in a bottom portion of the drum; conveying the particles in the trough out a first outlet; and conveying the particles in the bottom of the drum out a second outlet, separate from said first outlet and recovering said particles having a length above L1. In addition a spent catalyst particle mixture comprising relatively uncontaminated particles and heavily contaminated particles is density graded by suspending relatively uncontaminated and lightly contaminated particles above said heavily contaminated particles, causing the heavily contaminated particles to move upwardly along an inclined, vibrating surface and thereafter being collected at a first outlet, the lightly contaminated particles contacting a lower portion of said vibrating surface and being collected at a second outlet, and the relatively uncontaminated particles contacting a portion of said vibrating surface below that contacted by the lightly contaminated particles, and withdrawing said relatively uncontaminated particles from a third outlet. Spent catalyst particles can be length and density graded and subjected to regeneration and rejuvenation. |
