WO2021048687A1

WO2021048687A1 - An inlet section of a hydrocyclone, a hydrocyclone, use of a hydrocyclone and a plant comprising a hydrocyclone

Info

Publication number: WO2021048687A1
Application number: PCT/IB2020/058131
Authority: WO
Inventors: Charles GROCOTT
Original assignee: Mclanahan Corporation
Priority date: 2019-09-12
Filing date: 2020-09-01
Publication date: 2021-03-18
Also published as: GB201913136D0; GB2587003A

Abstract

An inlet section (10) of a hydrocyclone, the inlet section comprising: a body (20), the body comprising a feed port for receiving a feed of material in a carrier fluid; the body further comprising an egress aperture (70) for egressing the feed of material in the carrier fluid into to a main section of a hydrocyclone; the body further comprising an overflow aperture (40) for accommodating an overflow pipe; and wherein the body further comprises a directing ceiling (180), the directing ceiling comprising a ramped portion extending downwardly towards the egress aperture. A hydrocyclone for processing material in a carrier fluid, the hydrocyclone comprising the above inlet section. Use of the above hydrocyclone to process material in a carrier fluid. A plant for processing material in a carrier fluid, the plant comprising the above hydrocyclone.

Description

AN INLET SECTION OF A HYDROCYCLONE, A HYDROCYCLONE, USE OF A HYDROCYCLONE AND A PLANT COMPRISING A HYDROCYCLONE

Field of the Invention

The present invention relates to an inlet section of a hydrocyclone and, in particular, to an inlet section comprising a directing ceiling. The present invention further relates to a hydrocyclone comprising the inlet section, use of the hydrocyclone and a plant comprising the hydrocyclone.

Background of the Invention

Hydrocyclones are used to process material suspended in a carrier fluid in a wide range of applications, including classification, desliming, fines recovery, densifying, watering, sizing and washing. Accordingly, hydrocyclones are a vital part of many industries.

Typically, in use, a feed of material suspended in a carrier fluid is introduced into a hydrocyclone via a cylindrical inlet, or feed-receiving, section. The feed is supplied at such a velocity and pressure that the feed completes a pass around the internal diameter of the inlet section. During this circumnavigation of the inlet section, the feed descends the vertical height of the inlet section towards the main body of the hydrocyclone under gravity.

It is desirable to increase the entry velocity of the feed to increase the recovery of solid particles and the processing rate of a given hydrocyclone. However, the greater the entry velocity of the feed, the shallower the angle of descent of the feed within the inlet section. Above a certain entry velocity threshold, the feed does not descend down sufficiently during its first pass or circumnavigation. Here, the circulating material within the inlet section interferes with the feed entering the inlet section. In this way, the material inside the inlet section can partially blind the feed entry port by increasing the local pressure. This partial occlusion of the feed entry port is problematic as it causes turbulent re-entrainment of newly separated material and reduces the separation efficiency of the hydrocyclone. Generally, this problem is overcome by restricting the entry velocity of the feed, which has the drawback of limiting the processing capability and capacity on a given size of hydrocyclone.

Objects and aspects of the present invention seek to alleviate at least the above problems of the prior art.

Summary of the invention

According to a first aspect of the present invention, there is provided an inlet section of a hydrocyclone, the inlet section comprising: a body, the body comprising a feed port for receiving a feed of material in a carrier fluid; the body further comprising an egress aperture for egressing the feed of material in the carrier fluid into to a main section of a hydrocyclone; the body further comprising an overflow aperture for accommodating an overflow pipe; and wherein the body further comprises a directing ceiling, the directing ceiling comprising a ramped portion extending downwardly towards the egress aperture.

A ramped portion is a portion of the directing ceiling surface which is angled with respect to the horizontal and vertical. In use, the egress aperture and main section of the hydrocyclone are located at the lower end of the hydrocyclone beneath the overflow aperture.

The directing ceiling and ramped portion of the inlet section extend such they direct a feed from its point of entry, the feed port, towards the point of exit, the egress aperture. In use, the ramped portion channels and guides the carrier fluid and the material in the carrier fluid towards the egress aperture by acting as a physical barrier. In this way, the feed inside the inlet section is directed away from the feed port, reducing the interaction between the feed entering the inlet section and the feed inside of the inlet section. Accordingly, the ramped portion reduces and/or removes the ability of the feed inside the inlet section to partially blind or occlude the feed port after a first turn around the inlet section, enabling greater feed entry velocities and greater processing capabilities for a given hydrocyclone.

Preferably, the directing ceiling extends downwardly from a first edge of the feed port. Preferably, the first edge is the top edge of the feed port. Preferably, the first edge of the feed port is proximate the overflow aperture and removed from the egress aperture. Having the directing ceiling extend from the top edge of the feed port ensures that the directing ceiling directs the feed downwardly immediately upon its entry to the hydrocyclone.

Preferably, the directing ceiling extends around the entire inner boundary of the body. Preferably, the directing ceiling extends from the first edge to terminate at a position proximate a second edge of the feed port. Preferably, the directing ceiling extends around the entire inner boundary of the body from the first edge to terminate at a position proximate the second edge of the feed port. In use, these preferable features enable the directing ceiling to extend for the entire duration of a turn or pass of the feed inside of the inlet section increasing the effectiveness of the directing ceiling.

Preferably, the directing ceiling terminates at a position removed from the egress aperture. In this way, the inlet section comprises a section which resembles the typical cylindrical form of an inlet section after the directing ceiling, such that the feed inside the inlet section can form its normal vortex without the directional input of the directing ceiling prior to egressing through the egress aperture.

Preferably, the directing ceiling extends from the first edge to terminate at a position proximate a third edge of the feed port and removed from the first edge. Preferably, the first edge and the third edge are located on opposing sides of the feed port. By terminating closer to the third edge than the first edge, the directing ceiling extends the majority of the height of the feed port such that a physical barrier limits the occlusion of the feed entry port by the circulating feed.

Preferably, the second edge extends between the first edge and the third edge. Preferably, the directing ceiling terminates at a position on the second edge intermediate the first edge and the third edge. Alternatively, the directing ceiling terminates at the meeting point of the second edge and the third edge.

Preferably, the ramped portion is curved. The inlet section of a hydrocyclone is cylindrical and by curving, the ramped portion can circumnavigate all, or a portion of, the internal boundary of the inlet section. Preferably, the ramped portion extends from the feed port to the egress aperture to form a helix. In the inlet section of a hydrocyclone, and in the hydrocyclone itself, the feed forms a vortex. Where the ramped portion forms a helix, it closely resembles the vortex path taken by the feed inside of the inlet section. As such, a helical ramped portion reduces unnecessary disturbance of the vortex and reduces wear.

Preferably, the ramped portion completes more than half a single turn of a helix. Preferably, the ramped portion completes a single turn of a helix. More preferably, the ramped portion substantially completes a single turn of a helix. Most preferably, the ramped portion completes three-quarters of a single turn of a helix.

Preferably, the ramped portion substantially forms a circular helix. A circular helix is preferred as it resembles the cylindrical shape of typical inlet section.

Preferably, the ramped portion has a constant curvature. Preferably, the ramped portion has a constant torsion. More preferably, the ramped portion has a constant curvature and a constant torsion.

Preferably, the pitch of the ramped portion is less than the height of the feed port. Alternatively, the pitch of the ramped portion is equal to the height of the feed port. Alternatively, the pitch of the ramped portion is greater than to the height of the feed port.

Preferably, the axis of the helix of the ramped portion is substantially perpendicular to the axis that extends through the centre line of the feed port. Preferably, the axis of the helix of the ramped portion is substantially parallel with the vertical. Preferably, the axis of the helix of the ramped portion intersects the centre-point of the egress aperture. Preferably, the axis of the helix of the ramped portion intersects the centre-point of the overflow aperture.

Preferably, the width of the ramped portion is constant along its length.

Preferably, the body comprises a cylindrical portion extending from the terminus of the directing ceiling to the egress aperture. In this way, the inlet section comprises a section which resembles the typical cylindrical form of an inlet section after the directing ceiling, such that the feed inside the inlet section can form its normal vortex without the directional input of the directing ceiling prior to egressing through the egress aperture.

Preferably, the ramped portion extends at an angle of between 5 and 30° from the horizontal. More preferably, the ramped portion extends at an angle of between 10 and 25° from the horizontal. Even more preferably, the ramped portion extends at an angle of between 15 and 20° from the horizontal.

Preferably, the directing ceiling comprises an abrasion resistant material. More preferably, the directing ceiling consists of an abrasion resistant material. Preferably, the abrasion resistant material is a rubber, a polyurethane or a ceramic.

Preferably, the directing ceiling comprises a planar potion. Preferably, the planar portion is located between the feed port and the ramped portion. Preferably, the planar portion has a surface area less than half the surface area of the ramped portion.

According to a second aspect of the present invention there is provided a hydrocyclone for processing material in a carrier fluid, the hydrocyclone comprising the inlet section of the first aspect of the present invention, where the inlet section optionally comprises any of the preferable features of the first aspect.

According to a third aspect of the present invention there is provided use of the hydrocyclone of the second aspect to process material in a carrier fluid.

According to a fourth aspect of the present invention there is provided a plant for processing material a carrier fluid, the plant comprising the hydrocyclone of the second aspect.

Detailed Description of the Invention

Embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figure 1 depicts a perspective view of an inlet section of a hydrocyclone according to the first aspect of the present invention; and

Figure 2 depicts a second perspective view of the inlet section of Figure 1 , where the inlet section has been rotated to view the directing ceiling through the egress aperture.

Figures 1 and 2 of the drawings depict perspective views of an inlet section 10 of a hydrocyclone (not shown) in accordance with a first aspect of the present invention.

The inlet section 10 comprises a body 20, where the body 20 defines an internal volume 30 of the section 10. The body 20 comprises an overflow aperture 40 through which the internal volume 30 is accessible.

The overflow aperture 40 is substantially circular and is located in the top surface of the inlet section 10. The overflow aperture 40 is centrally aligned with the body 20. Bounding the edge of the overflow aperture 40 is an overflow aperture flange 50 comprising a series of threaded fixing members 60. In use, when the inlet section 10 is part of a hydrocyclone, the overflow aperture 40 is located at the top of the hydrocyclone and is securely fixed to an overflow pipe by the thread fixing members 60. Furthermore, the overflow aperture 40 accommodates a vortex finder which extends into the internal volume 30.

The body 20 further comprises an egress aperture 70. The egress aperture 70 is located on the opposing side of the body 20 to the overflow aperture 40. The egress aperture 70 is a substantially circular aperture which is centrally aligned with both the body 20 and the overflow aperture 40. As such the centre-point of the egress aperture 70 is vertically and coaxially aligned with the centre-point of the overflow aperture 40. Further, the plane occupied by the egress aperture 70 is substantially parallel with the plane occupied by the overflow aperture 40. In this preferred embodiment, the radius of the egress aperture 70 is approximately 1.5 times greater than that of the overflow aperture 40 such that the aperture size of the egress aperture 70 is over double the size of the overflow aperture 40. In general, the radius of the egress aperture 70 is larger than that of the overflow 40. The egress aperture 70 is bounded by an egress flange 80, where the egress flange 80 comprises a series of egress fixing apertures 90. In use, the egress aperture flange 80 and the egress aperture fixing apertures 90 are used to securely fix the inlet section 10 to a conical section of a hydrocyclone, such that through the egress aperture 70 the internal volume 30 of the inlet section 10 and the main section of the hydrocyclone are in fluid communication.

The body 20 comprises curved side walls 100 which extend between the edges of the overflow aperture 40 and the egress aperture 70 in a direction substantially parallel with the normal of the overflow aperture 40 and the normal of the egress aperture 70. The body 20 and curved side walls 100 have a generally cylindrical shape formed from two cylinders of different sizes and joined together by a stepped helical structure.

The body 20 further comprises a feed port 110. The feed port 110 extends from a feed aperture 120 to an opening 130 in the curved side walls 100, such that the feed port 110 and feed aperture 120 are in fluid communication with the internal volume 30. In use, the feed being processed is introduced into the inlet section 10 via the feed port 110. The feed port 110 extends to the opening 130 in a direction substantially parallel with the horizontal and the planes occupied by the overflow aperture 40 and the egress aperture 70.

The feed aperture 120 is located externally to the internal volume 30 and is substantially circular and occupies a plane substantially perpendicular to the planes occupied by the egress aperture 70 and the overflow aperture 40. The feed aperture 120 is bounded by a feed aperture flange 135 and a series of feed port fixing apertures 145 for securing the feed port 110 to an external pipework which, in use, supplies the feed to be processed. In this preferred embodiment, the radius of the feed aperture 120 is approximately a third the radius of the egress aperture 70. In general, the feed aperture 120 is smaller than the egress aperture 70.

The opening 130 has a cross-section with is substantially rectangular and comprises four edges: a top edge 140, a bottom edge 150, an inside edge 160 and an outside edge 170. The top edge 140 and the bottom edge 150 are parallel and oppose one another and are connected by the inside edge 160 and the outside edge 170. The bottom edge 150 is curved and extends in the plane of the curved side walls 100.

The outside edge 170 of the opening 130 is tangentially aligned with the curved side wall 100, whilst the inside edge 160 is located on the circumference of the curve side walls 100. Further, the opening 130 is offset from the centre of the body 10 such that, in use, the feed being processed is introduced tangentially into the inlet section 10.

The top edge 140 of the opening 130 is aligned with the overflow aperture 40, and a directing ceiling 180 extends from the top edge 140 towards the egress aperture 70. In use, the directing ceiling 180 directs the feed inside the inlet section 10 towards the egress aperture 70 by directing the feed downwards. The directing ceiling 180 having a width between the overflow aperture 40 and the interior surface of the curved side wall 100.

The directing ceiling 180 comprises a planar portion 190 which extends from the top edge 140 of the opening 130 to a ramped portion 200 of the directing ceiling 180. The planar portion 190 lies in the plane occupied by the overflow aperture 40.

The ramped portion 200 extends from the planar portion 190 through the internal volume 30 towards the egress aperture 70 in a downward circular helix of constant torsion and constant curvature. Thus, in this preferred embodiment, the ramped portion 200 is substantially helical. The axis of the helix of the ramped portion 200 is substantially parallel with the vertical and the normal of the overflow aperture 40 and egress aperture 70. The ramped portion 200 has a width extending from the interior surface of the curved side wall 100 to a position aligned with the edge of the overflow aperture 40 and is of constant width. The ramped portion 200 completes three- quarters of a turn of helix from the planar portion 190 to an end portion 210 of the directing ceiling 180.

The end portion 210 extends from the end of the ramped portion 200 to a terminus 220, with the end portion 210 decreasing in width as it extends towards the terminus 220. The width of end portion 190 is between the interior surface of the curved side wall 100 and an interior edge of the end portion 210, where the interior edge of the end portion 210 extends in a direction which is tangentially aligned with the edge of the overflow aperture 40.

The terminus 220 is flush and aligned with the inside edge 160, where the inside edge 160 is aligned with a position on the edge of the egress aperture 70. The inside edge 160 extends in a direction perpendicular with plane occupied by the egress aperture 70. As the terminus 220 is located flush with the inside edge 210, the terminus 220 is located at a position between the top edge 140 and the bottom edge 150 of the opening 130. The bottom edge 150 is proximate the egress aperture 70 and removed from the overflow aperture 40.

The directing ceiling 180 further comprises an interior wall 230, which extends between from the end portion 210 and the planar portion 190, and between the interior edge of the ramped portion 200 to the edge of the overflow aperture 40. In this way, the interior wall 230 reduces the volume of the internal volume 30 by blocking off the area above the ramped portion 200 and end portion 210 and prevents the feed or fluid from getting above the directing ceiling 180.

In use, a feed of material in a carrier fluid is injected into the inlet section 10 and the internal volume 30 through the feed port 110. The feed travels through the feed aperture 120 and opening 130 into the internal volume 30. The feed begins to pass around the curved side walls 100 of the body 20 and below the planar portion 190 of the directing ceiling 180 in a clockwise direction. The feed then encounters the ramped portion 200. The ramped portion 200 forces the feed to descend at a predetermined angle by acting as a ceiling and barrier. The feed subsequently passes three-quarters of the distance around the curved walls 100 of the body 20 with the ramped portion 200 enforcing a predetermined angle of descent. Likewise, the end portion 210 will then direct the feed downwards until its terminus 220 after which the feed can descend at its normal or natural angle. The terminus 220 is adjacent to the inside edge 160 of the feed port 110 and proximate the bottom edge 150. The curved side wall 100 between the bottom edge 150 and the egress aperture 70 direct the feed around the internal volume 30 beneath the opening 130. Thus, the directing ceiling 180 has forced the feed down a predetermined amount. Accordingly, circulating material’s effect on the blinding or occluding of the opening 130 and feed port 110 is controlled and limited by the directing ceiling 180.

Claims

1. An inlet section of a hydrocyclone, said inlet section comprising: a body, said body comprising a feed port for receiving a feed of material in a carrier fluid; said body further comprising an egress aperture for egressing the feed of material in the carrier fluid into to a main section of a hydrocyclone; said body further comprising an overflow aperture for accommodating an overflow pipe; and wherein said body further comprises a directing ceiling, said directing ceiling comprising a ramped portion extending downwardly towards said egress aperture.

2. The inlet section of claim 1, wherein said directing ceiling extends downwardly from a first edge of said feed port.

3. The inlet section of claim 2, wherein, in use, said first edge is the top edge of said feed port.

4. The inlet section of claim 2 or claim 3, wherein said first edge of said feed port is proximate said overflow aperture and removed from said egress aperture.

5. The inlet section of any one preceding claim, wherein said directing ceiling extends around the entire inner boundary of said body.

6. The inlet section of any one preceding claim, wherein said directing ceiling extends from said first edge to terminate at a position proximate a second edge of said feed port.

7. The inlet section of claim 6, wherein said directing ceiling terminates at a position removed from said egress aperture.

8. The inlet section of any one preceding claim, wherein said directing ceiling extends from said first edge to terminate at a position proximate a third edge of said feed port and removed from said first edge.

9. The inlet section of claim 8, wherein said first edge and said third edge are located on opposing sides of said feed port.

10. The inlet section of claim 9, wherein said second edge extends between said first edge and said third edge.

11. The inlet section of claim 10, wherein said directing ceiling terminates at a position on said second edge intermediate said first edge and said third edge.

12. The inlet section of claim 10, wherein said directing ceiling terminates at the meeting point of said second edge and said third edge.

13. The inlet section of any one preceding claim, wherein said ramped portion extends from towards said egress aperture to form a helix.

14. The inlet section of claim 13, wherein said ramped portion substantially completes a single turn of a helix.

15. The inlet section of claim 13 or claim 14, wherein said ramped portion substantially forms a circular helix.

16. The inlet section of claim 15, wherein said ramped portion has a constant curvature and a constant torsion.

17. The inlet section of any one of claims 13 to 16, wherein the axis of the helix of said ramped portion is substantially perpendicular to the axis that extends through the centre line of said feed port.

18. The inlet section of any one preceding claim, wherein the width of said ramped portion is constant along its length.

19. The inlet section of any one preceding claim, wherein said body comprises a cylindrical portion extending from the terminus of said directing ceiling to said egress aperture.

20. The inlet section of any one preceding claim, wherein the ramped portion extends at an angle of between 5 and 30° from the horizontal.

21. The inlet section of any one preceding claim, wherein the directing ceiling comprises an abrasion resistant material.

22. The inlet section of any one preceding claim, wherein the directing ceiling comprises a planar potion.

23. A hydrocyclone for processing material in a carrier fluid, said hydrocyclone comprising the inlet section of any one of claims 1 to 22.

24. Use of the hydocyclone of claim 23 to process material in a carrier fluid.

25. A plant for processing material in a carrier fluid, said plant comprising the hydrocyclone of claim 23.