Separating device and method with a return flow of heavy fraction

1. A device for separating a heavy fraction from a fluid, comprising:

a substantially cylindrical housing defining a main channel;

swirl means, positioned in the main channel, for transferring a rotating movement component to the fluid moving through the main channel, thereby separating a heavy fraction;

collecting means for collecting the separated heavy fraction, which radially surround openings in the cylindrical housing that are provided to let the heavy separated fraction leave the main channel;

an additional supply conduit concentric to the main channel, provided with an outlet, which additional supply conduit at least partly extends into the cylindrical housing; and

wherein the additional supply conduit is adapted to receive separated heavy fraction from the collecting means;

the additional supply conduit is provided with deflection means, which are positioned downstream of the outlet, the deflecting means causing a fluid exiting the outlet to move in a radial direction,

wherein

the outlet of the additional supply conduit is encircling the circumference of the additional supply conduit.

2. The device as claimed in claim 1 , wherein the outlet of the additional supply conduit comprises plural apertures that collectively encircle the circumference of the additional supply conduit.

3. The device as claimed in claim 1 , wherein at least a part of the outlet of the additional supply conduit has a helical shape.

4. The device as claimed in claim 1 , wherein the deflection means comprise a deflection body, positioned coaxial with the additional supply conduit and downstream of the outlet.

5. The device as claimed in claim 1 , wherein the projection of the outlet of the additional supply conduit on a plane perpendicular to the main channel is lying within the projection of the deflection means on the same plane perpendicular to the main channel.

6. The device as claimed in claim 1 , wherein the largest diameter of the deflection body is larger than the diameter of the outlet of the additional supply conduit.

7. The device as claimed in claim 1 , wherein the deflection means are substantially dish-shaped.

8. The device as claimed in claim 1 , wherein the deflection means are connected by a shaft, which shaft extends in axial direction in the additional supply conduit.

9. The device as claimed in claim 8 , wherein the diameter of the shaft with decreasing distance to the deflection means has an increasing diameter.

10. The device as claimed in claim 1 , wherein the concentric additional supply conduit comprises at least two separate non-concentric flow channels.

11. The device as claimed in claim 1 , wherein the deflection means are provided with a projection at its side away from the additional supply conduit.

12. The device as claimed in claim 1 , wherein the deflection means are conical, with a decreasing diameter towards the outlet of the additional supply conduit.

13. The device as claimed in claim 1 , wherein the collecting means comprises a collection space located around the openings in the cylindrical housing.

14. The device as claimed in claim 1 , wherein the openings in the cylindrical housing are elongated and extend in a direction perpendicular to the direction of the swirl-means in the main channel.

15. The device as claimed in claim 1 , wherein the openings in the cylindrical housing are at least partly surrounded by an opening edge, which opening edge extends into the cylindrical housing.

16. The device as claimed in claim 1 , wherein the cylindrical housing is provided with helical extending curvatures.

17. The device as claimed in claim 16 , wherein the rotational direction of the helically extending curvatures are substantially perpendicular to the longitudinal direction of the openings.

18. The device as claimed in claim 1 , wherein the deflection means are shaped such that they provide a rotational component to a fluid that flows through the additional supply conduit and contacts the deflection means.

19. The device as claimed in claim 1 , wherein the deflection means comprise a spray-nozzle.

20. The device as claimed in claim 1 , wherein the cylindrical housing of the main channel is conically tapered in a direction of flow.

21. A method for separating a heavy fraction from a fluid, comprising the steps:

A) supplying the fluid through a cylindrical housing and providing the fluid with a rotational movement component, wherein the cylindrical housing defines a main channel;

B) discharging a heavy fraction of the fluid through openings in the cylindrical housing; and

C) returning at least a part of the heavy fraction as discharged during step B) via a return channel to an additional supply conduit which is coaxially positioned in the main channel;

wherein the heavy fraction of the fluid as returned during step C) is expelled by an outlet that encircles the additional supply conduit channel and subsequently the expelled heavy fraction of the fluid is deflected by a deflection means, positioned downstream of the outlet, towards the exterior of the cylindrical housing.

22. The method as claimed in claim 21 , wherein the heavy fraction is substantially a fluid and in that a light fraction is substantially a gas.

23. The method as claimed in claim 21 , wherein the heavy fraction returned to the main channel by the return channel is provided with a rotational component.

24. The method as claimed in claim 21 , wherein only a part of the heavy fraction of the fluid discharged through openings in the wall of the main channel during step B) is returned into the main channel by the return channel.