CENTRIFUGAL SEPARATOR

Abstract

A centrifugal separator bowl, having a vertical rotational axis, the separator bowl defining a separation space, and including an upper bowl section having a first threading, the first threading having a first inner diameter and a first outer diameter and defining an upper surface, and a lower bowl section having a second threading corresponding to the first threading of the upper bowl section, the second threading having a second outer diameter and a second inner diameter and defining a lower surface. The upper surface of the first threading of the upper bowl section and the lower surface of the second threading of the lower bowl section form a screw connection. The upper surface of the first threading is inclined upward with a first angle from the first inner diameter to the first outer diameter and the lower surface of the second threading is inclined downward with a second angle from the second outer diameter to the second inner diameter relative to a horizontal plane extending perpendicular to the vertical rotation axis.

Claims

1. A centrifugal separator bowl, having a vertical rotational axis, the separator bowl defining a separation space, and comprising: an upper bowl section having a first threading, said first threading having a first inner diameter and a first outer diameter and defining an upper surface; and a lower bowl section having a second threading corresponding to the first threading of the upper bowl section, said second threading having a second outer diameter and a second inner diameter and defining a lower surface, wherein said upper surface of said first threading of the upper bowl section and said lower surface of said second threading of the lower bowl section form a screw connection, and wherein said upper surface of said first threading is inclined upward with a first angle from said inner diameter to said outer diameter and said lower surface of said second threading is inclined downward with a second angle from said outer diameter to said inner diameter relative to a horizontal plane extending perpendicular to said vertical rotation axis.

2. The centrifugal separator bowl according to claim 1, wherein said first angle and said second angle are the same.

3. The centrifugal separator bowl according to claim 1, wherein the upper bowl section is screwed into the lower bowl section.

4. The centrifugal separator bowl according to claim 1, wherein the lower bowl section is screwed into the upper bowl section.

5. The centrifugal separator bowl according to claim 1, wherein said angles are between 1° and 45°.

6. The centrifugal separator bowl according to claim 1, wherein said angles are between 5° and 30°.

7. The centrifugal separator bowl according to claim 1, wherein said angles are between 10° and 20°.

8. The centrifugal separator bowl according to claim 1, wherein said separator bowl has an inlet for feeding a fluid mixture to be separated into components into said separation space.

9. The centrifugal separator bowl according to claim 8, wherein said separator bowl has at least one outlet for discharge of a separated component of said fluid mixture from said separation space.

10. The centrifugal separator bowl according to claim 1, wherein a stack of frusto-conical separator discs is arranged in said separation space.

11. The centrifugal separator bowl according to claim 1, wherein the upper bowl section has a wall portion with a larger diameter arranged above said lower wall portion and with a surface facing downwards, the surface facing downwards being adapted to be in contact with a surface on said upper wall portion of said lower bowl section, thus forming a stop for said screw connection.

12. A centrifugal separator comprising the centrifugal separator bowl according to claim 1.

13. The centrifugal separator bowl according to claim 2, wherein the upper bowl section is screwed into the lower bowl section.

14. The centrifugal separator bowl according to claim 2, wherein the lower bowl section is screwed into the upper bowl section.

15. The centrifugal separator bowl according to claim 2, wherein said angles are between 1° and 45°.

16. The centrifugal separator bowl according to claim 3, wherein said angles are between 1° and 45°.

17. The centrifugal separator bowl according to claim 4, wherein said angles are between 1° and 45°.

18. The centrifugal separator bowl according to claim 2, wherein said angles are between 5° and 30°.

19. The centrifugal separator bowl according to claim 3, wherein said angles are between 5° and 30°.

20. The centrifugal separator bowl according to claim 4, wherein said angles are between 5° and 30°.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Further objects, features and advantages will appear from the appended claims and the following detailed description of several embodiments of the invention with reference to the drawings, in which:

[0018] FIG. 1 is a schematic view of a cross section of an embodiment of a centrifugal separator according to the invention.

[0019] FIG. 2 is a view of a cross-section of the connection area between the upper bowl section and the lower section according to an embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0020] FIG. 1 shows a schematic view of a cross-section of an embodiment of a centrifugal separator 20. The separator comprises a stationary frame 21, a spindle 22, which is rotatably supported in said frame 21 e.g. via two bearings, and a centrifugal separator bowl 1 rotatably arranged in said frame 21 adjoined to the axially upper end of said spindle 22 to rotate together with the spindle 22 around a vertical axis of rotation (X). The frame 21 may comprise more than one individual part, i.e. it may be assembled from several parts. A drive arrangement 23 is configured to rotate the spindle 22 with the centrifugal separator bowl 1. In these embodiments, the drive arrangement 23 forms part of the spindle, thus driving the centrifugal separator bowl 1 directly. The drive arrangement 23 comprises an electric motor and a rotor if the electric motor forms part of the spindle 22. In alternative embodiments, the drive arrangement may instead be connected to the spindle via a transmission, such that a first pulley is arranged on the electric motor, a second pulley is arranged on the spindle, and a belt extending between the first and second pullies. Alternatively, the transmission may be a gear transmission comprising cog wheels, or any other suitable transmission for transferring torque from the electric motor to the spindle.

[0021] The centrifugal separator bowl 1 encloses a separation space 25 in which a stack 26 of separation discs 27 is arranged in order to achieve effective separation of a fluid that is processed and separated into components. The separation discs 27 of the stack 26 have a frustoconical shape and are examples of surface-enlarging inserts. The stack 26 is fitted centrally and coaxially with the centrifugal separator bowl 1. In FIG. 2, only a few separation discs 27 are shown. The stack 26 may for example contain above 100 separation discs, such as above 200 separation discs.

[0022] The centrifugal separator 20 may be configured for separating the liquid feed mixture into at least one light phase and a heavy phase. The liquid feed mixture may comprise e.g. one liquid, or two liquids. The liquid feed mixture may comprise solid matter, which may be separated from the liquid feed mixture as part of the heavy phase.

[0023] The centrifugal separator 20 comprises an inlet 28 for the liquid feed mixture, at least one first outlet 29 for the heavy phase, and a second outlet 30 for the light phase. In the illustrated embodiment, the liquid feed mixture to be separated is fed from the bottom of the centrifugal separator 20 via the inlet 28 centrally into the centrifugal separator bowl 1, from which it is distributed to the separation space 25. During use of the centrifugal separator 20, the liquid feed mixture is separated into at least the heavy phase and the light phase in the separation space 25. The light phase flows towards the center of the separation space 25 and the heavy phase flows towards a radially outer periphery of the separation space 25. The separated light phase is lead from a central portion of the separation space 25 downwardly to the second outlet 30. That is, the second outlet 30 is arranged in fluid communication with the central portion of the separation space 25.

[0024] From a central portion of the centrifugal separator 1, the heavy phase is lead upwardly to the first outlet 29. The present invention is not limited to any particular types of liquid feed mixtures or separated fluid phases. Neither is the present invention limited to any particular inlet arrangement for the liquid feed mixture, nor to any particular second outlet 30 for the separated light phase.

[0025] In FIG. 2 Is illustrated a cross-section of an area of the centrifugal separator bowl 1 according to an embodiment disclosing a connection area between an upper bowl section 31, also named bowl hood, and a lower bowl section 32, also named bowl body. The upper bowl section 31 comprises a first wall 33 which has a lower wall portion 34. The lower wall portion 34 has an exterior first threading 35. The lower bowl section 32 comprises a second wall 36 which has an upper wall portion 37. The upper wall portion 37 has an interior second threading 38 corresponding to said exterior first threading 35. When the upper bowl section 31 and the lower bowl section 32 are mounted to form said centrifugal separator bowl 1 said first threading 35 and said second threading 38 are forming a screw connection 39 between them. Thus the upper wall portion 37 of the lower bowl section 32 is arranged outside of the lower wall portion 34 of the upper bowl section 31, in such a manner that the upper bowl section 31 being screwed into the lower bowl section 32.

[0026] Said screw connection 39 is formed by an upper surface 40 of said first threading 35 being in frictional contact with a lower surface 41 of said second threading 38. Said upper surface 40 of said first threading 35 is inclined upward with a first angle α from an inner diameter d1 of said first threading 35 to an outer diameter d2 of said first threading 35. Said inner diameter d1 is measured at the root of said first threading 35 and said outer diameter d2 is measured at the tip of said first threading 35. Said lower surface 41 of said second threading 38 is inclined downward with a second angle β from an outer diameter d3 of said second threading 38 to an inner diameter d4 of said second threading 38. Said outer diameter d3 is measured at the root of said second threading 38 and said inner diameter d4 is measured at the tip of said second threading 38. In embodiments said first angle α and said second angle β are the same. Said first and second angles α, β may be between 1° and 45°. In some embodiments said first and second angles α, β may be between 5° and 30°. In some embodiments said first and second angles α, β may be between 10° and 20°.

[0027] Above said lower wall portion 34 of the upper bowl section 31 there is a wall portion 42 with a larger diameter thus protruding radially outwards disclosing a surface 43 facing downwards which surface 43 is adapted to be in contact with a surface 44 on said upper wall portion 37 of said lower bowl section 32 facing upwards. When during mounting centrifugal separator bowl 1 by screwing together the upper and lower bowl sections 31, 32, the surfaces 43, 44 get in contact with each other they form a stop 45 of the screwing operation, and due to the frictional forces between the two surfaces 43, 44 thus also form an effective locking of said screw connection 39.

[0028] It is to be understood that the invention is not limited to the various example embodiments described above and shown in the drawings, but a person skilled in the art will realize that the example embodiments may be supplemented and modified in any manner within the scope of the invention as defined by the enclosed claims.