Nozzle/header design for polystyrene

Patent metadata

Field	Value
Publication number	US-10058794-B2
Application number	US-201615085464-A
Country	US
Kind code	B2
Filing date	Mar 30, 2016
Priority date	Mar 30, 2016
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

A vessel header includes lateral flow tubes arranged in a parallel configuration. The lateral flow tubes enter the vessel header through alternating vessel header penetrations with a single vessel header penetration per lateral flow tube. Each lateral flow tube has a perforated section within the vessel header having a non-circular cross-section having the shape of a circular sector, an elliptical sector, or an irregular quadrilateral. A method includes passing a molten polymer through the lateral flow tubes of the vessel header. The molten polymer exits the lateral flow tubes as strands through perforations in the lateral flow tubes within the vessel header. The method includes obtaining devolatilized polymer.

First claim

What is claimed is:

1. A devolatilizer vessel comprising:
a vessel header comprising a plurality of alternating vessel header penetrations; and
a plurality of lateral flow tubes arranged in a parallel configuration, wherein each lateral flow tube enters the vessel header through one of the alternating vessel header penetrations with a single vessel header penetration per lateral flow tube, wherein each lateral flow tube comprises a perforated section located within the vessel header, the perforated section comprising a non-circular cross-section, wherein the non-circular cross-section has the shape of a circular sector, an elliptical sector, or an irregular quadrilateral, wherein the non-circular cross-section has two straight sides, wherein a third side of the non-circular cross-section is an arc, wherein the two straight sides connect at an angle that is equal to or more than 70-76 degrees, and wherein each straight side connects with the arc at an angle that is greater than 90 degrees.

2. The devolatilizer vessel of claim 1 , wherein the perforations in the perforated section extend only across a portion of the two straight sides of the non-circular cross-section.

3. The devolatilizer vessel of claim 1 , wherein a majority of perforations in the lateral flow tubes have a maximum strand angle of equal to or less than 65 degrees.

4. The devolatilizer vessel of claim 1 , wherein the perforations in the lateral flow tubes are tapered holes.

5. The devolatilizer vessel of claim 4 , wherein all or a portion of the tapered holes have a linear taper.

6. The devolatilizer vessel of claim 4 , wherein all or a portion of the tapered holes are multiple internal tapered holes.

7. The devolatilizer vessel of claim 1 , wherein the lateral flow tubes are in fluid communication with an external distribution manifold.

8. The devolatilizer vessel of claim 1 , wherein the lateral flow tubes are formed of 304 stainless steel, AL-6XN stainless steel, or LDX 2101 stainless steel.

9. The devolatilizer vessel of claim 1 , wherein the lateral flow tubes are welded into the vessel header penetrations, or wherein the lateral flow tubes are internally flanged to the vessel header penetrations, or wherein the lateral flow tubes are externally flanged to the vessel header penetrations.

10. The devolatilizer vessel of claim 9 , wherein the lateral flow tubes are externally flanged to the vessel header penetrations, and wherein the external flanges are arranged in a staggered configuration.

11. The devolatilizer vessel of claim 1 , further comprising internal support structure supporting each lateral flow tube within the vessel header opposite the corresponding vessel header penetration.

12. The devolatilizer vessel of claim 11 , wherein the internal support structure accommodates horizontal expansion or contraction of the lateral flow tube.

13. The devolatilizer vessel of claim 11 , wherein the internal support structure is a sliding cradle comprising a support rail located opposite the vessel header penetration and above the lateral flow tube and a sliding hanger connecting the support rail and the lateral flow tube.

14. The devolatilizer vessel of claim 11 , wherein the internal support structure comprises a support cradle located opposite the corresponding vessel header penetration on which the lateral flow tube rests.

15. The devolatilizer vessel of claim 14 , wherein the support cradle is interior to the vessel header wall, or wherein the support cradle is exterior to the vessel header wall.

16. The devolatilizer vessel of claim 14 , wherein the support cradle is welded to the vessel interior.

17. The devolatilizer vessel of claim 16 wherein the support cradle is welded to the vessel interior along one or more weld arcs positioned inside the support cradle.

18. The devolatilizer vessel of claim 16 , wherein the support cradle is welded to the vessel interior along one or more weld arcs positioned inside the support cradle such that a weld root spacing between the weld arcs and vessel header penetration welds is minimized.

19. The devolatilizer vessel of claim 1 , wherein the lateral flow tubes are welded into the vessel header penetrations and are externally flanged to an external distribution manifold or internally flanged to the external distribution manifold.

20. The devolatilizer vessel of claim 1 , wherein the lateral flow tubes are externally flanged to the vessel header penetrations and to an external distribution manifold.

21. The devolatilizer vessel of claim 1 , further comprising an internal support structure supporting the lateral flow tubes within the vessel header opposite the vessel header penetrations, wherein the lateral flow tubes are welded into the vessel header penetrations and are externally flanged to an external distribution manifold, and wherein the perforated sections of the lateral flow tubes extend substantially the entire length of the lateral flow tubes from the vessel header penetrations to the internal support structure.

22. The devolatilizer vessel of claim 1 , further comprising an internal support structure supporting the lateral flow tubes within the vessel header opposite the vessel header penetrations, wherein the lateral flow tubes are externally flanged to the vessel header penetrations and to an external distribution manifold, and wherein the perforated sections of the lateral flow tubes extend substantially the entire length of the lateral flow tubes from the vessel header penetrations to the internal support structure.

23. The devolatizer vessel of claim 1 , wherein the non-circular cross-section has the shape of an irregular quadrilateral.

24. A method comprising:
passing a molten polymer through lateral flow tubes of a vessel header of a devolatilizer vessel, wherein the lateral flow tubes are arranged in a parallel configuration and enter the vessel header through a plurality of alternating vessel header penetrations with a single vessel header penetration per lateral flow tube;
wherein the molten polymer exits the lateral flow tubes as strands through perforations in the lateral flow tubes within the vessel header, and wherein the lateral flow tubes have a non-circular cross-section, and wherein the non-circular cross-section has the shape of a circular sector, an elliptical sector, or an irregular quadrilateral, wherein the non-circular cross-section has two straight sides, wherein a third side of the non-circular cross-section is an arc, wherein the two straight sides connect at an angle that is equal to or more than 70-76 degrees, and wherein each straight side connects with the arc at an angle that is greater than 90 degrees; and
obtaining devolatilized polymer from the devolatilizer vessel.

25. The method of claim 24 , wherein a majority of the strands exit the perforations at a maximum strand angle of equal to or less than 52.5 degrees.

26. The method of claim 24 , wherein the devolatilized polymer is polystyrene comprising equal to or less than about 1000 ppm of styrene monomer.

Assignees

• Fina Technology

Inventors

• Tomlinson John
• Sosa Jose
• Corleto Carlos R
• Kennedy Roy

Classifications

• C08L25/06

  Polystyrene · CPC title

• B01D1/06

  Evaporators with vertical tubes · CPC title

• C08F6/005

  from solid polymers · CPC title

• B01D1/22

  by bringing a thin layer of the liquid into contact with a heated surface {(B01D1/065 takes precedence)} · CPC title

• B01D1/18

  to obtain dry solids (B01D1/24 takes precedence) · CPC title