Elimination of polymer fouling in fluidized bed gas-phase fines recovery eductors

Patent metadata

Field	Value
Publication number	US-10988554-B2
Application number	US-201916522088-A
Country	US
Kind code	B2
Filing date	Jul 25, 2019
Priority date	Oct 14, 2016
Publication date	Apr 27, 2021
Grant date	Apr 27, 2021

Abstract

An eductor, a process and apparatus for gas phase polymerization of olefins in a polymerization reactor are disclosed. The process and apparatus employ an eductor which has an inlet which makes a bend of less than about 90° toward the outlet after entering the mixing chamber of the eductor.

First claim

What is claimed is:

1. An eductor comprising:
a first tubular body having a hollow interior and comprising:
a first inlet and a first outlet spaced apart from the first inlet along a central axis, and
a sidewall circumscribing the central axis and defining a mixing chamber; and

a second tubular body having a hollow interior and comprising a second inlet and a spaced apart second outlet, wherein the second tubular body extends into the mixing chamber through the sidewall of the first tubular body between the first inlet and the first outlet,
wherein the second tubular body comprises a bend of less than 90° toward the first outlet after extending into the mixing chamber.

2. The eductor of claim 1 , wherein the second tubular body makes a first bend of about 45° from perpendicular toward the first outlet before entering the mixing chamber and a second bend of about 45° toward the first outlet after entering the mixing chamber.

3. The eductor of claim 1 , wherein the second tubular body is substantially parallel to the central axis at the second outlet.

4. The eductor of claim 1 , wherein the first inlet is a solid fines inlet and the second inlet is a motive gas inlet.

5. The eductor of claim 4 , wherein the second outlet further comprises a nozzle in the mixing chamber.

6. The eductor of claim 1 , wherein the first inlet is a motive gas inlet and the second inlet is a solid fines inlet.

7. The eductor of claim 1 , wherein the first tubular body and the second tubular body below the second bend after entering the mixing chamber are coaxial.

8. The eductor of claim 1 , wherein the first tubular body is at least partially cylindrical in shape.

9. The eductor of claim 1 , wherein the second tubular body is at least partially cylindrical in shape.

10. The eductor of claim 1 , wherein the first tubular body is at least partially conical in shape.

11. The eductor of claim 1 , further comprising exit piping downstream of the first outlet which is not parallel with the axis of the first tubular body.

12. The eductor of claim 1 , further comprising a converging-diverging nozzle adjacent to the first outlet.

13. An eductor comprising:
a first tubular body having a hollow interior and comprising:
a first inlet and a first outlet spaced apart from the first inlet along a central axis, and
a sidewall circumscribing the central axis and defining a mixing chamber; and

a second tubular body having a hollow interior and comprising a second inlet and a spaced apart second outlet,
wherein the second tubular body extends into the mixing chamber through the sidewall of the first tubular body between the first inlet and the first outlet,
wherein the second inlet is oriented at an angle less than perpendicular to the axis of the first tubular body toward the first outlet before extending into the mixing chamber, and
wherein the second tubular body comprises a bend at an angle less than perpendicular toward the first outlet after extending into the mixing chamber.

14. The eductor of claim 13 , wherein the second tubular body makes a first bend of about 45° from perpendicular toward the first outlet before entering the mixing chamber and a second bend of about 45° toward the first outlet after entering the mixing chamber.

15. A process for polymerizing olefins comprising:
contacting one or more olefins with a catalyst in a polymerization reactor under polymerization conditions to form a gas stream comprising fine polymer particles and unreacted olefins;
passing the gas stream to a fines separator to separate the fine polymer particles from the unreacted olefins;
passing the fine polymer particles from the fines separator to the eductor of claim 1 ; and
introducing a motive gas into the eductor to convey the fine polymer particles back to the polymerization reactor.

16. The process of claim 15 , further comprising passing the unreacted olefins from the fines separator to a heat exchanger to cool the unreacted olefins, passing the cooled unreacted olefins to a compressor to compress the cooled unreacted olefins, and introducing the cooled and compressed unreacted olefins back to the polymerization reactor.

17. The process of claim 16 , wherein the motive gas comprises at least a portion of the cooled and compressed unreacted olefins.

18. A process for polymerizing olefins comprising:
contacting one or more olefins with a catalyst in a polymerization reactor under polymerization conditions to form a gas stream comprising fine polymer particles and unreacted olefins;
passing the gas stream to a fines separator to separate the fine polymer particles from the unreacted olefins;
passing the fine polymer particles from the fines separator to the eductor of claim 13 ; and
introducing a motive gas into the eductor to convey the fine polymer particles back to the polymerization reactor.

19. The process of claim 18 , further comprising passing the unreacted olefins from the fines separator to a heat exchanger to cool the unreacted olefins, passing the cooled unreacted olefins to a compressor to compress the cooled unreacted olefins, and introducing the cooled and compressed unreacted olefins back to the polymerization reactor.

20. The process of claim 19 , wherein the motive gas comprises at least a portion of the cooled and compressed unreacted olefins.

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Lowell Jeffrey S
• Hendrickson Gregory G
• Price Ralph J

Classifications

• B01J4/002 Primary

  Nozzle-type elements (nozzle-type reactors B01J19/26) · CPC title

• B01J8/004

  by means of a nozzle · CPC title

• B01J19/26

  Nozzle-type reactors, i.e. the distribution of the initial reactants within the reactor is effected by their introduction or injection through nozzles · CPC title

• C08F2/34

  Polymerisation in gaseous state · CPC title

• C08F6/005

  from solid polymers · CPC title