Apparatus and method for sealing around an articulated arm

Abstract

A sealing unit 13 for use around an articulated arm 1 of the type comprising a flexible outer sleeve comprises a first annular flange 19 configured to surround an articulated arm 1 and arrangeable to inhibit fluid flow axially along a surface of the outer sleeve at a first axial position, a second annular flange 21 configured to surround the articulated arm 1, the second annular flange 21 axially spaced from the first annular flange to define an annular region 25 therebetween, the second flange 21 arrangeable to inhibit fluid flow axially along the surface of the outer sleeve at a second axial position spaced from the first axial position and an evacuation mechanism configured to draw fluid out of the annular region, thereby lowering a fluid pressure within the annular region 25 such that, in use, the outer sleeve is drawn toward the annular region 25. A plurality of sealing units 13 may be mounted to a housing 9 to form a sealing device on a clean side of a wall 5 allowing an articulated arm 1 to extend through an aperture unit 7 from the clean side to a contaminated side of the wall 5. The articulated arm 1 may be used for drilling operations.

Claims

1. A sealing unit for use around an articulated arm, the articulated arm of the type comprising a flexible outer sleeve, the sealing unit comprising:a first annular flange configured to surround an articulated arm, the articulated arm of the type comprising a flexible outer sleeve, the first annular flange arrangeable to inhibit fluid flow axially along a surface of the outer sleeve at a first axial position;a second annular flange configured to surround the articulated arm, the second annular flange axially spaced from the first annular flange to define an annular region therebetween, and arrangeable to inhibit fluid flow axially along the surface of the outer sleeve at a second axial position spaced from the first axial position; andan evacuation mechanism configured to draw fluid out of the annular region, thereby lowering a fluid pressure within the annular region such that, in use, the outer sleeve is drawn toward the annular region.

2. The sealing unit according to claim 1, wherein the first annular flange is less flexible than the second annular flange.

3. The sealing unit according to claim 1 or claim 2, wherein the first annular flange is thicker than the second annular flange.

4. The sealing unit according to any preceding claim, further comprising a third annular flange configured to surround the articulated arm, the third annular flange axially spaced from the first annular flange, opposite the second annular flange, to define a further annular region therebetween, and arrangeable to inhibit fluid flow axially along the surface of the outer sleeve at a third axial position spaced from the first axial position.

5. The sealing unit according to claim 4, wherein the evacuation mechanism is configured to draw fluid out of the further annular region, thereby lowering a fluid pressure within the further annular region such that, in use, the outer sleeve is drawn toward the further annular region.

6. The sealing unit according to claim 4, further comprising a further evacuation mechanism configured to draw fluid out of the further annular region, thereby lowering a fluid pressure within the region such that, in use, the outer sleeve is drawn toward the further annular region.

7. The sealing unit according to any preceding claim, further comprising a flushingmechanism configured to push fluid into the annular region, thereby raising a fluid pressure within the region such that, in use, contaminants are blown out of the annular region.

8. A sealing device comprising:a plurality of sealing units according to any proceeding claim; anda housing in which each of the plurality of sealing unit are mounted, such that a single articulated arm may extend through each of the plurality of sealing units.

9. A sealing system comprising:the sealing unit according to any one of claims 1 to 7; andan articulated arm comprising a flexible outer sleeve, the articulated arm extending through the sealing unit.

10. The sealing system according to claim 9, further comprising:a drive unit for moving the articulated arm through the sealing unit; anda feedback controller configured to determine a resistance to movement of the articulated arm through the sealing unit and control the evacuation mechanism to increase the fluid pressure within the region.

11. A sealing system comprising:the sealing device according to claims 8; andan articulated arm comprising a flexible outer sleeve, the articulated arm extending through the sealing unit.

12. A method of sealing around an articulated arm comprising a flexible outer sleeve,the method comprising the steps of:providing the system of claim 9; anddrawing fluid out of the annular region with the evacuation mechanism, thereby5 lowering a fluid pressure within the region such that the outer sleeve is drawntoward the annular region.14

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