Multi-stage pusher centrifuge

• US 20040206689A1
• Filed: 04/05/2004
• Published: 10/21/2004
• Est. Priority Date: 04/16/2003
• Status: Active Grant

• Current Assignee: Ferrum Process Systems AG
• Original Assignee: Ferrum AG
• Inventors: Geiger, Roy, Reinach, Harald
• Granted Patent: US 7,017,756 B2
• Time in Patent Office: Days
• US Class Current: 210/369
• CPC Class Codes: B04B 11/06 Arrangement of distributors or collectors in centrifuges
• CPC Class Codes: B04B 3/02 discharging solid particles from the bowl by means coaxial with the bowl axis and moving to and fro, i.e. push-type centrifuges

Abstract

The invention relates to a multi-stage pusher centrifuge (1) for the separation of a mixture (2) into a solid cake (3) and into a liquid phase (4). The multi-stage pusher centrifuge (1) includes an outer screen drum (6) rotatable about an axis of rotation (5) and at least one screen stage (7) arranged in the outer screen drum (6), a mixture distributor (8) arranged in the screen drum (6) with a pusher base apparatus (9), with either the screen stage (7) or the pusher base apparatus (9) being arranged movably to and fro along the axis of rotation (5) such that the solid cake (3) is displaceable by means of the pusher base apparatus (9). The multi-stage centrifuge further includes an infeed device (10) with which the mixture (2) can be introduced via the mixture distributor (8) into an empty space (11) which arises on the displacement of the solid cake (3) by the pusher base apparatus (9), with the pusher base apparatus (9) including a pre-acceleration funnel (12) which extends in a substantially divergent manner in the direction towards the infeed device (10) and the pre-acceleration funnel (12) being designed as a pre-acceleration screen (12).

Claims

1. A multi-stage pusher centrifuge for the separation of a mixture (2) into a solid cake (3) and into a liquid phase (4), including an outer screen drum (6) rotatable about an axis of rotation (5) and at least one screen stage (7) arranged in the outer screen drum (6), a mixture distributor (8) arranged in the screen drum (6) with a pusher base apparatus (9), with either the screen stage (7) or the pusher base apparatus (9) being arranged movably to and fro along the axis of rotation (5) such that the solid cake (3) is displaceable by means of the pusher base apparatus (9), and including an infeed device (10) with which the mixture (2) can be introduced via the mixture distributor (8) into an empty space (11) which arises on the displacement of the solid cake (3) by the pusher base apparatus (9), with the pusher base apparatus (9) including a pre-acceleration funnel (12) which extends in a substantially divergent manner in the direction towards the infeed device (10), characterised in that the pre-acceleration funnel (12) is designed as a pre-acceleration screen (12).

2. A multi-stage pusher centrifuge in accordance with claim 1, wherein the pre-acceleration funnel (12) extends at a substantially constant pre-acceleration angle (β

) in a conically divergent manner in the direction towards the infeed device (10).

3. A multi-stage pusher centrifuge in accordance with claim 1, wherein the pre-acceleration funnel (12) has a curved extent and the pre-acceleration angle (β

) of the pre-acceleration funnel (12) becomes larger in the direction towards the infeed device (10).

4. A multi-stage pusher centrifuge in accordance with claim 1, wherein the pre-acceleration funnel (12) has a curved extent and the pre-acceleration angle (β

) of the pre-acceleration funnel (12) becomes smaller in the direction towards the infeed device (10).

5. A multi-stage pusher centrifuge in accordance with claim 1, wherein the pre-acceleration screen (12) is designed as a two-stage filter with a coarse filter (121) and a fine filter (122).

6. A multi-stage pusher centrifuge in accordance with claim 1, wherein a collection device (13) is provided at the mixture distributor (8) for the draining of liquid phase (4).

7. A multi-stage pusher centrifuge in accordance with claim 1, wherein a value of the pre-acceleration angle (β

) of the pre-acceleration screen (12) with respect to the axis of rotation (5) lies between 0° and

45°

, specifically between 0° and

10°

or between 10° and

45°

, in particular between 25° and

45°

, preferably between 15° and

35°

.

8. A multi-stage pusher centrifuge in accordance with claim 1, wherein the pre-acceleration funnel (12) is designed and arranged such that the pre-acceleration screen (12) is rotatable at a pre-settable speed of rotation about an axis of rotation (5) by means of a rotational drive (14).

9. A multi-stage pusher centrifuge in accordance with claim 1, wherein, at the infeed device (10), an inlet funnel (16) is arranged which extends at a substantially constant opening angle (α

) in a conically divergent manner in the direction towards the pusher base apparatus (9).

10. A multi-stage pusher centrifuge in accordance with claim 1, wherein the inlet funnel (16) has a curved extent and the opening angle (α

) of the inlet funnel (16) becomes larger in the direction towards the pusher base apparatus (9).

11. A multi-stage pusher centrifuge in accordance with claim 1, wherein the inlet funnel (16) has a curved extent and the opening angle (α

) of the inlet funnel (16) becomes smaller in the direction towards the pusher base apparatus (9).

12. A multi-stage pusher centrifuge in accordance with claim 1, wherein the inlet funnel (16) is designed as a pre-filter screen (17) for the pre-separation of liquid phase (4) from the mixture (2).

13. A multi-stage pusher centrifuge in accordance with claim 1, wherein the pre-filter screen (17) is designed as a two-stage screen with a coarse screen (171) and a fine screen (172).

14. A multi-stage pusher centrifuge in accordance with claim 1, wherein collection means (18) are provided for the collection and draining of the liquid phase (4) from the pre-filter screen (17).

15. A multi-stage pusher centrifuge in accordance with claim 1, wherein the inlet funnel (16) is rotatably arranged about a drive axis (19) and can be rotated at a pre-settable speed of rotation about the drive axis (19) by means of a drive (20).