Adjustable lift engager

1. A lift engager for providing a stream of fluidized catalyst particles, the lift engager comprising:

a vessel with an inlet configured to receive catalyst from a reaction zone;

a first conduit within the vessel configured to supply lift gas into the lift engager, the first conduit comprising a fixed member and a movable member secured to the fixed member and configured to adjust a length of the first conduit within the vessel;

a second conduit inside the first conduit and configured to provide fluidized catalyst to a regeneration zone;

a sleeve disposed about both of the fixed member and the movable member, wherein the sleeve includes an inner surface comprising threads, and wherein the movable member includes an outer surface comprising threads configured to engage the threads of the inner surface of the sleeve; and

a collar secured to the fixed member and extending over a first end of the sleeve.

2. The lift engager of claim 1 wherein the fixed member includes a first end, and wherein the movable member comprises a first end, and wherein the first end of the fixed member and the first end of the moveable member are configured complementarily to engage each other and prevent rotation of the movable member relative to the fixed member.

3. The lift engager of claim 2 , wherein both first ends comprise a plurality of alternating teeth and gaps, the teeth of one first end configured to be received in the gaps of the other first end.

4. The lift engager of claim 1 wherein an outer surface of the sleeve comprises a worm gear.

5. The lift engager of claim 4 further comprising:

a shaft engaging the worm gear and extending out of the vessel and configured to rotate in or to cause the sleeve to rotate relative to the fixed member.

6. The lift engager of claim 4 further comprising:

a detent on the outer surface of the fixed member, and,

wherein the sleeve comprises a plurality of bearings configured to engage the detent on the outer surface of the fixed member.

7. A lift engager for providing fluidized catalyst particles, the lift engager comprising:

a vessel with an inlet configured to receive catalyst;

a first conduit within the vessel configured to supply lift gas into the lift engager, the first conduit comprising a fixed member, a sleeve secured to the fixed member, and a movable member engaging the sleeve and configured to move relative to the fixed member to adjust a length of the first conduit within the vessel;

a second conduit inside of the first conduit and configured to provide fluidized catalyst; and

a detent on an outer surface of the fixed member,

wherein the sleeve comprises a plurality of bearings configured to engage the detent.

8. The lift engager of claim 7 , wherein the sleeve includes an inner surface comprising threads, and wherein the moveable member includes an outer surface comprising threads configured to engage the threads of the inner surface of the sleeve.

9. The lift engager of claim 8 , wherein the fixed member includes a first end, and wherein the movable member comprises a first end, and wherein the first end of the fixed member and the first end of the moveable member are configured complementarily to engage each other and prevent rotation of the movable member relative to the fixed member.

10. The lift engager of claim 9 , wherein both first ends comprise a plurality of alternating teeth and gaps, the teeth of one first end configured to be received in the gaps of the other first end.

11. The lift engager of claim 7 wherein the outer surface of the sleeve comprises a worm gear.

12. The lift engager of claim 11 further comprising:

a shaft engaging the worm gear and extending out of the vessel and configured to rotate to adjust a position of the moveable member relative to the fixed member.

13. The lift engager of claim 7 further comprising:

a collar secured to the fixed member and extending over a first end of the sleeve.

14. A process for providing fluidized catalyst, the process comprising:

passing catalyst particles from a reaction zone to a vessel;

passing a stream of fluidizing gas into the vessel via a first conduit, wherein the first conduit comprises a fixed member, a sleeve rotatably secured to the fixed member, and a movable member engaging the sleeve, the moveable member configured to move in relative to the fixed member to adjust a length of the first conduit;

passing fluidized catalyst to a regeneration zone through a second conduit, wherein within the vessel the second conduit extends within the first conduit; and

rotating a shaft extending out of the vessel in order to rotate the sleeve of the first conduit to adjust a length of the first conduit.