Process for catalyst activation
The invention relates generally to a catalyst activator, and in particular to a catalyst activator for heat conditioning a catalyst, comprising: a) a vessel for containing a catalyst charge having an internal diameter of at least 1.2 meters and/or an internal volume of at least 5 m 3 ; b) a fluidization grid plate disposed in said vessel, said fluidization grid plate and having an upper major surface and a lower major surface; c) an array of generally conical depressions in said upper major surface that overlap by less than 17%; and d) an array of holes perforating said fluidization grid plate, said holes extending from at least some of said generally conical depressions through said lower surface.
1. A process for activating a batch of polymerisation catalyst which comprises fluidising the batch of polymerisation catalyst in a fluidisation zone of an activator vessel, wherein the activator vessel comprises a fluidisation zone and a disengagement zone above the fluidisation zone, the diameter of the fluidisation zone of the activator vessel being at least 1 m, the height of the fluidised bed of catalyst being at least twice the diameter of the fluidisation zone and the height of the disengagement zone being between 1 to 3 m.
2. A process according to claim 1 wherein the height of the fluidised bed of catalyst is at least three times the diameter, for example at least four times the diameter.
3. A process according to claim 1 wherein the height of the fluidised bed of catalyst is between 2 and 8 m, and preferably between 4 and 8 m.
4. A process according to claim 1 wherein the expansion on fluidisation is above 100%, such as at least 120%.
5. A process according to claim 1 wherein the diameter of the fluidisation zone of the activator vessel is at least 1.2 m, and preferably at least 1.5 m.
6. A process according to claim 1 wherein the settled bed has a depth between 1.8 and 3 m.
7. A process according to claim 1 wherein the settled bed has a bulk volume of greater than 1.5 m 3 .
8. A process according to claim 1 wherein the height of the disengagement zone is between 1 to 2 bed diameters.
9. A process according to claim 1 wherein the height of the disengagement zone is between 0.25 to 0.75 times the height of the fluidisation zone.
10. A process according to claim 1 wherein the disengagement zone has the same cross-sectional area as the fluidisation zone such that the fluidisation zone and disengagement zone form a single cylindrical activator vessel having a total height between 3 and 11 m.
11. A process for activating a batch of polymerisation catalyst which comprises fluidising the batch of polymerisation catalyst in a fluidisation zone of an activator vessel, the diameter of the fluidisation zone of the activator vessel being at least 1.2 m and the height of the fluidised bed of catalyst being at least twice the diameter of the fluidisation zone.
12. A process according to claim 11 wherein the height of the fluidised bed of catalyst is at least three times the diameter, for example at least four times the diameter.
13. A process according to claim 11 wherein the height of the fluidised bed of catalyst is between 2 and 8 m, and preferably between 4 and 8 m.
14. A process according to claim 11 wherein the expansion on fluidisation is above 100%, such as at least 120%.
15. A process according to claim 11 wherein the diameter of the fluidisation zone of the activator vessel is at least 1.5 m.
16. A process according to claim 11 wherein the settled bed has a depth between 1.8 and 3 m.
17. A process according to claim 11 wherein the settled bed has a bulk volume of greater than 1.5 m 3 .
18. A process according to claim 11 wherein the activator vessel comprises a fluidisation zone and a disengagement zone above the fluidisation zone, the height of the disengagement zone being between 1 to 3 m.
19. A process according to claim 11 wherein the activator vessel comprises a fluidisation zone and a disengagement zone above the fluidisation zone, the height of the disengagement zone being between 1 to 2 bed diameters.
20. A process according to claim 11 wherein the activator vessel comprises a fluidisation zone and a disengagement zone above the fluidisation zone, the disengagement zone having the same cross-sectional area as the fluidisation zone such that the fluidisation zone and disengagement zone form a single cylindrical activator vessel having a total height between 3 and 11 m.