Apparatus for reducing attrition of particulate matter in a chemical conversion process

• US 4,486,207 A
• Filed: 12/20/1982
• Issued: 12/04/1984
• Est. Priority Date: 06/22/1981
• Status: Expired due to Term

• Current Assignee: Atlantic Richfield Company Incorporated (BP PLC)
• Original Assignee: Atlantic Richfield Company Incorporated (BP PLC)
• Inventors: Baillie, Lloyd A.
• Primary Examiner(s): RICHMAN, BARRY
• Application Number:
  US06/451,371
• Time in Patent Office: 715 Days
• Field of Search: 275/567, 422/147, 55/455, 55/456, 55/459 R, 55/459 D, 209/144
• US Class Current: 55/455
• CPC Class Codes: B01D 45/12 by centrifugal forces centrifuges B04B; cyclones B04C
• CPC Class Codes: B01J 8/0055 using cyclones
• CPC Class Codes: B04C 5/04 Tangential inlets
• CPC Class Codes: B04C 5/081 Shapes or dimensions
• CPC Class Codes: B04C 5/181 Bulkheads or central bodies in the discharge opening
• CPC Class Codes: B04C 9/00 Combinations with other devices, e.g. fans, expansion chambers, diffusors, water lockswith filters B01D50/00

Abstract

An apparatus for separating solid particles from vapor is disclosed. The apparatus includes a novel inlet system, a novel particle outlet system and a chamber having novel dimensional relationships which result in an apparatus that separates solid particles from vapor with less attrition, or "break-up" of particulate matter, while maintaining a high separation efficiency at high loading conditions, e.g., the apparatus maintains a tangential wall velocity of less than about 50 feet per second and separates, from a mixture of solid particles and vapor, more than about 95% of the solid particles that are larger than about 20 microns in diameter while processing more than about 200 cubic feet of the mixture per second.

This apparatus is particularly suited to at least partially seperating solid particles from a mixture of vapors and solid particles, the mixture being of the type which arises when restoring the catalytic activity of solid particles previously used to promote or carry out a chemical conversion such as hydrocarbon cracking.

Claims

1. In an apparatus for separating solid particles from a first fluid stream which includes a mixture of vapor and said particles, said apparatus including a body that defines a chamber defined by an interior cylindrical surface, inlet means for introducing said first fluid stream mixture into said chamber, fluid outlet means for withdrawing a second fluid stream substantially free of said particles from said chamber, and particle outlet means for withdrawing at least a portion of said particles that has been separated from said mixture in said chamber, the improvement comprising:

said inlet means comprising a plurality of inlet passageway means wherein each said inlet passageway means is a means for conducting an inlet stream associated therewith along a substantially straight path tangentially into said chamber to induce said particles contained therein to move toward said interior cylindrical surface, said plurality of inlet passageway means is situated such that said path of one inlet stream will impinge upon the path of a downstream inlet stream associated with a downstream inlet passageway means to induce said particles contained in the impinging stream to be deflected away from said cylindrical surface;

whereby said mixture is introduced into said chamber at a high velocity while reducing contact of said solid particles with said cylindrical surface so as to maintain separation efficiency while decreasing particle attrition.

2. The apparatus of claim 1 wherein the plurality of passageway means comprises at least three passageway means.

3. The apparatus of claim 1 wherein the plurality of passageway means comprises at least four passageway means.

4. The apparatus of claim 1 wherein the plurality of passageway means comprises between about five and about twelve passageway means.

5. The apparatus of claim 1, 2, 3 or 4 wherein the plurality of passageways comprise a plurality of uncurved primary vane means.

6. The apparatus of claim 5 wherein said plurality of passageway means further comprise a plurality of secondary vanes, each said secondary vane cooperating with at least one of said primary vane means to define at least one of said passageway means.

7. The apparatus of claim 6 wherein each of said secondary vanes is substantially parallel to at least one of said primary vane means.

8. The apparatus of claim 5 wherein said primary vane means are positioned in a substantially symmetrical configuration about said chamber.

9. The apparatus of claim 1 wherein the solid particle size ranges from about 8 to about 12 microns.

10. The apparatus of claim 1 wherein the radius of said chamber is between 4 and 10 feet and the height of said chamber ranges from about 4 feet to about 50 feet.

11. The apparatus of claim 1 wherein the product of the chamber height and the inlet area of each said passageway means is greater than about 56 cubic feet.

12. The apparatus of claim 11 wherein the product of said chamber height and said inlet area is greater than about 67 cubic feet.

13. The apparatus of claim 1 wherein the radius of said chamber is selected such that the tangential wall velocity of the mixture is less than 50 feet per second.

14. The apparatus of claim 13 wherein the radius of said chamber is selected such that the tangential wall velocity of the mixture is between 20 and 40 feet per second.

15. The apparatus of claim 13 wherein the inlet fluid flow rate is between 200 and 600 cubic feet per second.

16. The apparatus of claim 15 wherein the radius of said chamber is selected such that the tangential wall velocity of the mixture is between 20 and 40 feet per second.

17. The apparatus of claim 1 wherein the inlet area of each of the passageway means is between about 4 and about 12 square feet and the inlet radius of each said passageway means is between about 2.5 and about 7 feet, and the outlet radius is between about 0.5 and about 2 feet.

18. The apparatus of claim 17 wherein said inlet radius, Ri, the chamber height, h, and the chamber radius, Rw, are selected so that the following formula is satisfied:

space="preserve" listing-type="equation">(Rih/Rw).sup.0.89 <

11(ft).sup.1.1.

19. The apparatus of claim 18 wherein Ri,h and Rw are selected so that the following formula is satisfied:

space="preserve" listing-type="equation">(Rih/Rw).sup.0.89 <

9(ft).sup.1.1.

20. The apparatus of claim 17 wherein the product of said inlet radius and said inlet area is greater than about 16 cubic feet.

21. The apparatus of claim 20 wherein the product of said inlet radius and said inlet area is greater than about 19 cubic feet.