Cyclonic separation device comprising two cyclones linked by an optimised pipe unit

1. A device for the cyclonic separation of solid particles contained in a fluid, comprising:

a primary cyclone chamber;

a secondary cyclone chamber;

at least one inlet channel for fluid loaded with solid particles, opening into said primary cyclone chamber;

at least one outlet channel for fluid cleaned of the solid particles, into which opens said secondary cyclone chamber; and

a ducting unit connecting said primary cyclone chamber to said secondary cyclone chamber;

in which said ducting unit is surrounded by the primary cyclone chamber;

wherein said ducting unit comprises:

a core forming a limit of said secondary cyclone chamber, said core having an outer surface provided with at least one helical groove having a bottom that diverges from a longitudinal axis of said secondary cyclone chamber in a direction towards said secondary cyclone chamber; and

a cap covering a part of said core in such a way as to delimit, with said at least one helical groove, a helical channel having an inlet opening into said primary cyclone chamber and an outlet opening into said secondary cyclone chamber.

2. The device according to claim 1 , in which the secondary cyclone chamber is integrally surrounded by the primary cyclone chamber.

3. The device according to claim 1 , in which the outlet channel of the device extends through the core, along the longitudinal axis of the secondary cyclone chamber.

4. The device according to claim 3 , in which a part at least of the outlet channel of the device is delimited by a surface provided with vortex breaker splines.

5. The device according to of claim 1 , in which said at least one helical groove comprises several helical grooves regularly distributed around the longitudinal axis of the secondary cyclone chamber.

6. The device according to claim 1 , in which the cap is formed of a wall of revolution centred with respect to the longitudinal axis of the secondary cyclone chamber.

7. The device according to claim 1 , in which the primary cyclone chamber is delimited externally by an outer annular wall centred with respect to the longitudinal axis of the secondary cyclone chamber and including a convergent tapered portion.

8. The device according to claim 7 , in which said outer annular wall a divergent tapered portion connected to the convergent tapered portion of said outer annular wall at the level of a neck of the latter.

9. The device according to claim 1 , in which the secondary cyclone chamber is delimited externally by an inner annular wall comprising a convergent tapered portion and a divergent tapered portion connected to each other at the level of a neck of said inner annular wall.

10. The device according to claim 1 , in which the primary cyclone chamber opens into a primary collection chamber intended to receive the solid particles separated within the primary cyclone chamber, the device including first vortex breaker blades at the outlet of the primary cyclone chamber.

11. The device according to claim 1 , in which the secondary cyclone chamber opens into a secondary collection chamber intended to receive the solid particles separated within the secondary cyclone chamber, the device including second vortex breaker blades at the outlet of the secondary cyclone chamber.

12. The device according to claim 1 , in which said at least one inlet channel has a helical shape.