Air/oil separator

• US 6,893,478 B2
• Filed: 03/06/2003
• Issued: 05/17/2005
• Est. Priority Date: 03/16/2002
• Status: Active Grant

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: Care, Ian C, Foord, Colin A, Mountney, Michael J, McMillan, Alison J
• Primary Examiner(s): Hopkins, Robert A.
• Application Number:
  US10/379,675
• Publication Number:
  US 20040098956A1
• Time in Patent Office: 803 Days
• Field of Search: 553/37, 554/00, 554/01, 554/06, 961/88, 961/89, 961/90
• US Class Current: 55/337
• CPC Class Codes: B01D 2275/307 Porosity increasing in flow direction
• CPC Class Codes: B01D 45/14 generated by rotating vanes, discs, drums or brushes
• CPC Class Codes: B01D 46/003 including coalescing means for the separation of liquid
• CPC Class Codes: B01D 46/0056 with rotational movement
• CPC Class Codes: F01M 13/04 having means for purifying air before leaving crankcase, e.g. removing oil
• CPC Class Codes: F01M 2013/0422 Separating oil and gas with a centrifuge device
• CPC Class Codes: F05B 2220/302 in gas turbines
• CPC Class Codes: F05B 2220/704 the other apparatus being a gas turbine

Abstract

An air/oil separator (40) comprises a rotor (60) and a casing (62) surrounding the rotor (60). The casing (60) has an inlet (64) at a first axial position (A) for the supply of an air and oil mixture into the air/oil separator (40). The rotor (60) has an outlet (66) for discharging cleaned air from the air/oil separator (40). The rotor (60) carries a plurality of porous members (68, 70, 72). The porous members (68, 70, 72) have an inlet (74) at a second axial position (B) and an outlet (76) at a third axial position (C). The third axial position (C) is arranged axially between the first axial position (A) and the second axial position (B). A first passage (88) supplies the air and oil mixture from the inlet (64) in the casing (62) to the inlet (74) to the porous members (68, 70, 72). A second passage (94) supplies cleaned air from the porous members (68, 70, 72) to the outlet (66) in the rotor (60). In use the air and oil mixture flows through the porous members (68, 70, 72) in the opposite direction to the air and oil mixture flowing through the first passage (88).

Claims

1. An air/oil separator comprising a rotor and a casing surrounding the rotor, the casing having an inlet at a first axial position for supply of an air and oil mixture into the air/oil separator, the rotor having an outlet for discharging cleaned air from the air/oil separator, the rotor carrying at least one porous member, the at least one porous member having an inlet at a second axial position and an outlet at a third axial position, the third axial position being arranged axially between the first axial position and the second axial position, means to define a first passage for the flow of the air and oil mixture axially from the inlet in the casing to the inlet to the at least one porous member, means to define a second passage for the flow of the cleaned air from the at least one porous member to the outlet in the rotor, whereby in use the air and oil mixture flowing through the at least one porous member flows in the opposite direction to the air and oil mixture flowing through the first passage.

2. An airfoil separator as claimed in claim 1 wherein the outlet from the rotor is at a fourth axial position, the second axial position being arranged axially between the third axial position and the fourth axial position, whereby in use the cleaned air flowing through the outlet from the rotor flows in the opposite direction to the air and oil mixture flowing through the at least one porous member.

3. An air/oil separator as claimed in claim 1 wherein the means to define the first passage and the means to define the second passage comprises a member surrounding the at least one porous member and spaced from the casing, the member extending axially from the second axial position to the third axial position and radially inwardly and axially from the third axial position to the first axial position.

4. An air/oil separator as claimed in claim 1 wherein the means to define the first passage comprises a member surrounding the at least one porous member and spaced from the casing, the member extending axially from the second axial position to the first axial position.

5. An air/oil separator as claimed in claim 1 wherein the inlet is arranged to direct the air and oil mixture tangentially into the air/oil separator.

6. An air/oil separator as claimed in claim 1 wherein the inlet has means to swirl the air and oil mixture before the air and oil mixture enters the air/oil separator.

7. An air/oil separator as claimed in claim 6 wherein the means to swirl the air and oil mixture comprises a pipe having a first bend and a second bend.

8. An air/oil separator as claimed in claim 1 wherein the casing has an inner surface, the inner surface comprising a layer of a porous material.

9. An air/oil separator as claimed in claim 8 wherein the porous material is a porous metal matrix.

10. An air/oil separator as claimed in claim 1 comprising a plurality of porous member arranged in flow series.

11. An air/oil separator as claimed in claim 10 wherein the porous members have different porosities.

12. An air/oil separator as claimed in claim 11 wherein the porous member with the finest porosity is at the inlet of the at least one porous member and the porous member with the coarsest porosity is at the outlet of the at least one porous member.

13. An air/oil separator as claimed in claim 1 wherein the at least one porous member is a porous metal matrix.

14. An air/oil separator as claimed in claim 1 wherein the at least one porous member is annular, the first passage is annular in the second passage is annular.

15. An air/oil separator comprising a rotor and a casing surrounding the rotor, the casing having an inlet at a first axial position for supply of an air and oil mixture into the air/oil separator, the rotor having an outlet for discharging cleaned air from the air/oil separator, the rotor carrying at least one porous member, the at least one porous member having an inlet at a second axial position and an outlet at a third axial position, the third axial position being arranged axially between the first axial position and the second axial position, means to define a first passage for the flow of the air and oil mixture axially from the inlet in the casing to the inlet to the at least one porous member, means to define a second passage for the flow of the cleaned air from the at least one porous member to the outlet in the rotor, whereby in use the air and oil mixture flowing through the at least one porous member flows in the opposite direction to the air and oil mixture flowing through the first passage and wherein the means to define the first passage and the means to define the second passage comprises a member surrounding the at least one porous member and spaced from the casing, the member extending axially from the second axial position to the third axial position and radially inwardly and axially from the third axial position to the first axial position and wherein the member comprises a frustoconical portion and a cylindrical portion.