Fluid inlet device, use, and method of retrofitting

1. In a fluid inlet device suitable for introducing a mixture of liquid and gas into a vessel, which fluid inlet device comprises:

an inlet flow channel having an inlet end for receiving the mixture of liquid and gas; and

a plurality of curved guiding vanes placed one behind the other along the inlet flow channel,

wherein each vane comprises an intercepting part extending towards the inlet end of the inlet flow channel, and an outwardly directed deflecting part defining a generally convex side and a generally concave side of the curved vane,

wherein the deflecting parts of two consecutive vanes form an outlet channel of the inlet device and define a main direction of gas flow in the outlet channel, the improvement comprising:

providing at least one of the vanes with a liquid catcher channel at least part of which extends along a rim of the vane and which additionally extends from an upstream position with respect to the vane to a downstream position,

wherein the rim of the vane is slanted between the upstream position and the downstream position such that the slant deviates from the main direction of gas flow by and angle of at least 10 degrees but not larger than 75 degrees.

2. The improved fluid inlet device according to claim 1 , wherein the upstream position is at a rim of the vane.

3. The improved fluid inlet device according to claim 1 , wherein the liquid catcher channel is curved.

4. The fluid improved inlet device according to claim 1 , wherein the main direction of gas flow during normal operation is horizontal, wherein the deflecting part of the vane extends between upper and lower rims, wherein the upstream position is at a first distance from the lower rim, and wherein the downstream position is at a second, smaller, distance from the lower rim.

5. The improved fluid inlet device according to claim 1 , wherein the fluid inlet device comprises walls defining a box-like structure, wherein the liquid catcher channel is arranged on a part of the vane extending out of the box-like structure, and wherein the catcher channel at its upstream position is sealingly arranged with respect to one of the walls.

6. The improved fluid inlet device according to claim 1 , wherein the width of the deflecting part of the vane decreases in a downstream direction.

7. The improved fluid inlet device according to claim 1 , wherein a plurality of liquid catcher channels is arranged on the vane.

8. The improved fluid inlet device according to claim 1 , wherein two liquid catcher channels are arranged that deviate in different directions from the main direction of gas flow.

9. The improved fluid inlet device according to claim 3 , wherein the liquid catcher channel extends from a first channel rim behind the convex side of the vane to a second longitudinal channel rim located in the plane defined by the curved vane or beyond that plane towards the concave side of the vane.

10. The improved fluid inlet device according to claim 3 , wherein the liquid catcher channel is connected to or integrally formed with the longitudinal rim of the curved vane.

11. The improved fluid inlet device according to claim 1 , wherein the liquid catcher channel has a downstream end that extends until the downstream end of the trailing end of the vane.

12. The improved fluid inlet device according to claim 1 , wherein the deflecting part of at least one of the vanes has a longitudinal rim which is provided with a liquid catcher channel.

13. The improved fluid inlet device according to claim 1 , wherein at least two ladders of vanes are stacked one above the other, and wherein a liquid catcher channel is arranged along at least one of the lower rim of an upper vane, the upper rim of the vane below.

14. A method of retrofitting a fluid inlet device suitable for introducing a mixture of liquid and gas into a vessel,

which fluid inlet device comprises:

an inlet flow channel having an inlet end for receiving the mixture of liquid and gas; and

a plurality of curved guiding vanes placed one behind the other along the inlet flow channel,

wherein each vane comprises an intercepting part extending towards the inlet end of the inlet flow channel, and an outwardly directed deflecting part defining a generally convex side and a generally concave side of the curved vane,

wherein the deflecting parts of two consecutive vanes form an outlet channel of the inlet device and define a main direction of gas flow in the outlet channel,

which method comprises:

providing at least one of the vanes with a liquid catcher channel at least part of which extends along a rim of the vane and which additionally extends from an upstream position with respect to the vane to a downstream position, and

wherein the rim of the vane is slanted between the upstream position and the downstream position such that the slant deviates from the main direction of gas flow by and angle of at least 10 degrees but not larger than 75 degrees.

15. The method according to claim 14 , wherein the step of providing at least one of the vanes with a liquid catcher channel comprises connecting to the vane a vane end part, wherein at least part of the liquid catcher channel is arranged on the vane end part.

16. The improved fluid inlet device according to claim 1 , wherein the slant deviates from the main direction of gas flow by an angle of at least 20 degrees and not larger than 75 degrees.

17. The improved fluid inlet device according to claim 1 , wherein the slant deviates from the main direction of gas flow by an angle of at least 30 degrees and not larger than 75 degrees.

18. The improved fluid inlet device according to claim 1 , wherein the slant deviates from the main direction of gas flow by an angle of at least 65 degrees and not smaller than 10 degrees.

19. The improved fluid inlet device according to claim 1 , wherein the liquid catcher channel has a downstream end that extends beyond the trailing rim of the vane.

20. The improved fluid inlet device according to claim 3 , wherein the maximum angle formed by a tangential of the curved liquid catcher channel with the main flow direction is 20 degrees and not larger than 75 degrees.

21. The improved fluid inlet device according to claim 20 , wherein the maximum angle formed by a tangential of the curved liquid catcher channel with the main flow direction is at least 10 degrees and not larger than 75 degrees.