CENTRIFUGAL SEPARATOR

Abstract

A centrifugal separator (10) includes a housing (12), which extends along a central axis (14) and has a separating chamber wall (24) for delimiting a separating chamber (26) that is fed by an inlet channel (44) for polyphasic fluid. A central immersion tube (50) is provided for discharging a first fluid phase and an outlet channel (54) is provided for discharging a second fluid phase. An expansion chamber (30), which widens radially outward with respect to the separating chamber and is radially outwardly delimited by an expansion chamber wall (30), is provided between the separating chamber and the outlet channel, The separating chamber conically widens from the inlet channel, as seen along the central axis, toward the expansion chamber.

Claims

1. A centrifugal separator (10) comprising a housing (12), which extends along a central axis (14) and has a separating chamber wall (24) for delimiting a separating chamber (26) that is fed by an inlet channel (44) for polyphasic fluid, wherein a central immersion tube (50) is provided for discharging a first fluid phase and an outlet channel (54) is provided for discharging a second fluid phase, wherein an expansion chamber (30), which widens radially outward with respect to the separating chamber (26) and is radially outwardly delimited by an expansion chamber wall (32), is provided between the separating chamber (26) and the outlet channel (54), wherein the separating chamber (26) conically widens from the inlet channel (44), as seen along the central axis (14), toward the expansion chamber (30).

2. The centrifugal separator (10) according to claim 1, wherein an angle of inclination (36), measured relative to the central axis (14), of the separating chamber wall (24) is between 2? and 20?.

3. The centrifugal separator (10) according to claim 1, wherein the immersion tube (50) extends over at most 60% of a length (28), measured along the central axis (14), of the separating chamber (26).

4. The centrifugal separator (10) according to claim 3, wherein a ratio between the length (28), measured along the central axis (14), of the separating chamber (26) and a largest diameter (34) of the separating chamber (26) is between 6:1 and 1:1.

5. The centrifugal separator (10) according to claim 1, wherein the expansion chamber (30) comprises a fluid discharge section (70), which is spaced apart from the central axis (14), is on a bottom and, with respect to an orientation perpendicular to the central axis (14), has a slope (72) which is similar to a screw thread and assists the discharge of the second fluid phase.

6. The centrifugal separator (10) according to claim 1, wherein the outlet channel (54) comprises a bottom section (74), which, with respect to an orientation perpendicular to the central axis (14), has an outlet channel slope (76) which assists the discharge of the second fluid phase.

7. The centrifugal separator (10) according to claim 1, wherein the expansion chamber (30) has a fluid guiding section (78) which extends around the central axis (14) in frustoconical or pagoda-shaped fashion and is on a bottom.

8. The centrifugal separator (10) according to claim 1, wherein the inlet channel (44) has a boundary wall (46), which is on an outside with respect to the central axis (14) and tangentially adjoins a section (48) of the separating chamber wall (24) and/or wherein the outlet channel (54) has a boundary wall (56), which is on the outside with respect to the central axis (14) and tangentially adjoins a section (58) of the expansion chamber wall (32).

9. The centrifugal separator (10) according to claim 1, wherein the inlet channel (44) has a rectangular cross section and/or wherein the outlet channel (54) has a rectangular cross section.

10. The centrifugal separator (10) according to claim 1, wherein an annular transition region (38) between one end (40) of the separating chamber wall (26) and a boundary section (42) covering the expansion chamber (30) is sharp-edged or rounded.

11. The centrifugal separator (10) according to claim 2, wherein the angle of inclination (36) is between 2.5? and 15?.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Further features and advantages are the subject of the following description and of the diagrammatic illustration of embodiments.

[0023] In the drawing:

[0024] FIG. 1 shows a front view of one embodiment of a centrifugal separator;

[0025] FIG. 2 shows a side view of the centrifugal separator according to FIG. 1;

[0026] FIG. 3 shows a plan view of the centrifugal separator according to FIG. 1;

[0027] FIG. 4 shows a side view of the centrifugal separator along a sectional plane denoted IV-IV in FIG. 1 (central axis is in the sectional plane);

[0028] FIG. 5 shows an enlarged illustration of a detail, denoted V in FIG. 4, of a separating chamber wall;

[0029] FIG. 6 shows a side view of a further embodiment of a centrifugal separator;

[0030] FIG. 7 shows a side view of a further embodiment of the centrifugal separator; and

[0031] FIG. 8 shows a side view of a further embodiment of the centrifugal separator.

DETAILED DESCRIPTION

[0032] In the drawing, a centrifugal separator is denoted as a whole by the reference sign 10.

[0033] The centrifugal separator 10 comprises a housing 12, which has a substantially rotationally symmetrical form with respect to a central axis 14; cf. FIG. 1 and FIG. 2. The central axis 14 extends between a first end 16 of the centrifugal separator 10 at which a top 18, extending perpendicular to the central axis 14, is formed and a second end 20 at which a bottom 22, extending perpendicular to the central axis 14, is formed.

[0034] The housing 12 has a separating chamber wall 24, which delimits a separating chamber 26 from the top 18 along the central axis 14, wherein the separating chamber 26 has a length 28 measured parallel to the central axis 14. The housing 12 has an expansion chamber 30, which is offset and arranged directly adjacent along the central axis 14 in relation to the separating chamber 26. The expansion chamber 30 is delimited by an expansion chamber wall 32 of the housing 12 and by the bottom 22 of the second end 20.

[0035] The separating chamber 26 has a conically widening form from the first end 18 in the direction of the expansion chamber 30, that is to say a diameter, measured perpendicularly in relation to the central axis 14, of the separating chamber 26 increases toward the expansion space 30 until a largest diameter 34 of the separating chamber 26 is reached. The conical widening of the separating chamber 26 is associated with a (negative) angle of inclination 36 of the separating chamber wall 24 relative to the central axis 14.

[0036] The separating chamber 26 leads into a boundary section 40, which is annular-disk-shaped and covers the expansion chamber 26, at an annular transition region 38. The transition region 38 may have a sharp-edged or rounded form.

[0037] The expansion chamber 30 has a diameter 42 measured perpendicularly in relation to the central axis 14. The diameter 42 of the expansion chamber 30 is larger than the largest diameter 34 of the separating chamber 26.

[0038] Close to the top 18, the separating chamber 26 is connected to an inlet channel 44 (cf. FIGS. 3 and 4). The inlet channel 44 preferably has a rectangular cross section. A boundary wall 46, which is on the outside with respect to the central axis 14, of the inlet channel 44 is in particular formed so as to tangentially adjoin a section 48 of the separating chamber wall 24; cf. FIG. 3.

[0039] An immersion tube 50 is arranged on the top 18 of the housing 12. The immersion tube 50 extends along the central axis 14 into the separating chamber 26; cf. FIG. 4. A length 52 of the immersion tube 50 that is accommodated in the separating chamber 26 is measured parallel to the central axis 14.

[0040] The expansion chamber 30 is connected to an outlet channel 54, wherein the outlet channel 54 preferably has a rectangular cross section. A boundary wall 56, which is on the outside with respect to the central axis 14, of the outlet channel 54 is in particular formed so as to tangentially adjoin a section 58 of the expansion chamber wall 32; cf. FIG. 3.

[0041] During operation of the centrifugal separator 10, the inlet channel 44 feeds a polyphasic fluid into the separating chamber 26, wherein the polyphasic fluid is composed in particular of fluid phases of different densities (light fraction and heavy fraction).

[0042] In the separating chamber 26, the polyphasic fluid is guided along an inner side 60 of the separating chamber wall 24, resulting in the formation of a flow which extends helically around the central axis 14 and has a flow component that points toward the expansion chamber 30.

[0043] The flow-induced centrifugal forces cause a radially outwardly directed acceleration, in particular of the heavy fraction, and the deposition of the heavy fraction on the inner side 60 of the separating chamber wall 24.

[0044] The light fraction undergoes a flow reversal in the vicinity of the bottom 22 and moves along the central axis 14 toward the immersion tube 50. The light fraction is discharged from the separating chamber 26 via the immersion tube 50.

[0045] A radially outwardly directed centrifugal force 64 also acts on the constituents 62 of the heavy fraction that are arranged on the inner side 60 of the separating chamber wall 24 after separation; cf. FIG. 5. The centrifugal force 64 has a first component 66 and a second component 68. The first component 66 acts on the constituents 62 of the heavy fraction as normal force and is aligned perpendicularly in relation to the inner side 60 of the separating chamber wall 24.

[0046] The second component 68 of the centrifugal force 64 is aligned parallel to the inner side 60 of the separating chamber wall 24. As a result of the conical widening of the separating chamber 26 along the central axis 14, the second component 68 of the centrifugal force 64 is aligned toward the expansion chamber 30. This causes an acceleration of the constituents 62 of the heavy fraction toward the expansion chamber 30 and an increased rate at which they are transported away from the separating chamber 26 into the expansion chamber 30.

[0047] The magnitude of the second component 68 of the centrifugal force 64 depends on the magnitude of the angle of inclination 36. A larger angle of inclination 36 measured with respect to the central axis 14 is associated with a second component 68 of the centrifugal force 64 that is larger in absolute terms.

[0048] If the constituents 62 of the heavy fraction are present in the expansion chamber 30, the enlarged diameter 42 of the expansion chamber 30 causes the rotational speed of the heavy fraction to decelerate, and the heavy fraction is discharged from the expansion chamber 30 via the outlet channel 54; cf. FIG. 1, for example.

[0049] Operating states of the centrifugal separator 10 during which constituents 62 of the heavy fraction accumulate on the bottom 18 are conceivable. As a result, the discharge of the constituents 62 of the heavy fraction out of the expansion chamber 30 can be adversely affected.

[0050] In order to improve the discharge of the heavy fraction from the expansion chamber 30, in a further embodiment of the centrifugal separator 10 there is provided a first fluid discharge section 70, which is spaced apart from the central axis 14, is on the bottom and, with respect to an orientation perpendicular to the central axis 14, has a slope 72 which is similar to a screw thread; cf. FIG. 6.

[0051] It is also possible to achieve an improvement in the discharge of the heavy fraction with a bottom section 74 of the outlet channel 54, wherein the bottom section 74, with respect to an orientation perpendicular to the central axis 14, has an outlet channel slope 76.

[0052] Operating states are also conceivable during which a heavy fraction proportion in the expansion chamber 30 and/or the separating chamber 26 stably rotates close to the central axis 14 and as a result does not reach the outlet channel 54. To avoid such operating states, fluid guiding sections on the bottom are provided in further embodiments of the centrifugal separator 10.

[0053] For example, a frustoconical fluid guiding section 78 is provided; cf. FIG. 7, or a pagoda-shaped fluid guiding section 80 is provided; cf. FIG. 8. The fluid guiding sections 78, 80 extend annularly around the respective central axis 14. The tops of the fluid guiding sections 78, 80 that face the separating chamber 26 or the expansion chamber 30 form inclined guide surfaces for guiding the constituents 62 of the heavy fraction radially outward, in particular toward the outlet channel 54.