PRODUCTION OF IMPROVED CATALYST-TYPE PARTICLES USING LENGTH AND DENSITY GRADING

摘要

Abstract of the DisclosureA mixture of shaped, catalyst particles comprisinggenerally cylindrical, free flowing catalyst particleshaving substantially the same diameter and of varying lengthare length graded into a first group of particles having alength below a predetermined length, L1, said length L1being in the range of from 0.8 to about 24 millimeters andat a value of L/D greater than one, and a second group ofparticles having a length greater than L1, by: feeding thecatalyst mixture into a cylindrical drum having inwardlyopening indentations in a cylindrical wall thereof, theindentions having a transverse diameter of substantially L1;rotating the drum about a longitudinal axis thereof at aspeed sufficient entrap in the indentations and convey theparticles having a length below L1 and comprising the firstgroup upwardly to a height permitting the particles to fallinto a fixed, upwardly opening trough, while retaining par-ticles having a length above L1 in a bottom portion of thedrum; conveying the particles in the trough out a firstoutlet; and conveying the particles in the bottom of thedrum out a second outlet, separate from said first outletand recovering said particles having a length above L1. Inaddition a spent catalyst particle mixture comprising rela-tively uncontaminated particles and heavily contaminatedparticles is density graded by suspending relatively uncon-taminated and lightly contaminated particles above saidheavily contaminated particles, causing the heavily contam-inated particles to move upwardly along an inclined, vibrat-ing surface and thereafter being collected at a first out-let, the lightly contaminated particles contacting a lowerportion of said vibrating surface and being collected at asecond outlet, and the relatively uncontaminated particlescontacting a portion of said vibrating surface below thatcontacted by the lightly contaminated particles, and with-drawing said relatively uncontaminated particles from athird outlet. Spent catalyst particles can be length anddensity graded and subjected to regeneration and rejuvena-tion.