WO2008155574A2

WO2008155574A2 - Magnetic separator device

Info

Publication number: WO2008155574A2
Application number: PCT/GB2008/050458
Authority: WO
Inventors: John Marlowe
Original assignee: Magnom Corporation Limited
Priority date: 2007-06-19
Filing date: 2008-06-18
Publication date: 2008-12-24
Also published as: GB0711835D0; WO2008155574A3; GB2450335A

Abstract

A separator device for removing magnetisable material from a fluid in which said material is suspended, comprises a first annular magnet (28), a second magnet (30) located within the boundary of said first magnet and a pair of metal plates (32), each of said magnets having faces of opposite magnetic polarity and each of said plates being disposed in abutment with a respective one of said faces of each magnet. Each of said plates has a plurality of passage means (40, 47, 50) for the passage of fluid from one side of the plate to the other and a plurality of projections (42, 44, 46, 48) defining magnetic pole pieces located adjacent to the passage means, the magnetic pole pieces on one of the plates being aligned with the magnetic pole pieces on the other of the plates and forming axially extending regions of magnetic attraction to which magnetic material passing through the adjacent passage means is attracted.

Description

MAGNETIC SEPARATOR DEVICE

DESCRIPTION

The present invention relates to magnetic separator devices, in particular to magnetic separator devices for removing particulate magnetisable material from a fluid in which the magnetisable material is suspended.

Fluid such as engine oil which circulates to an engine and/or gear box, and hydraulic fluid which circulates in hydraulic systems tends to accumulate material from metallic surfaces with which the fluid comes into contact. Such suspended particulate metallic material accelerates wear of the surfaces, thereby generating even more metallic particulate material.

Conventional filters fail to filter out a substantial amount of particulate magnetisable material from the fluid. In addition, as there is no indication of the quantity of magnetisable material in the fluid, the fluid is conventionally changed after the engine or hydraulic system has been operated for a certain period of time, in order to limit possible damage.

WO97/04873 discloses a magnetic filter device in the form of a flat- faced annular magnet having each of two identical parallel plates in contact with a respective one of the flat faces of the magnets. Each plate has a plurality of recesses about its outer perimeter to form radially- extending magnetic pole pieces and the plates are oriented so that the recesses and pole pieces on the one plate are axially aligned with the recesses and pole pieces on the other plate. Axially opposite recesses define passages for the fluid and regions from which magnetic material is extracted and the pole pieces define regions to which magnetic material is attracted and retained.

In accordance with a first aspect of the present invention, a separator device for removing magnetisable material from a fluid in which said material is suspended, comprises a first magnet, a second magnet spaced from said first magnet and a pair of metal plates, each of said magnets having faces of opposite magnetic polarity, each of said plates being disposed in abutment with a respective one of said faces of each magnet, each of said plates having a plurality of passage means for the passage of fluid from one side of the plate to the other and a plurality of projections defining magnetic pole pieces located adjacent to the passage means, the magnetic pole pieces on one of the plates being aligned with the magnetic pole pieces on the other of the plates and forming regions of magnetic attraction to which magnetic material passing through the adjacent passage means is attracted.

By providing two magnets in contact with each plate, it is possible to increase the efficiency with which the magnetisable material is removed from the fluid in which it is suspended.

Each of the plates preferably comprises first and second magnet abutment portions in abutment with said first and second magnets respectively.

Preferably, at least one of said passage means is located between the first and second magnet abutment portions. Preferably, a plurality of said passageways is located between the first and second magnet abutment portions. in one embodiment, said first magnet is substantially annular, and it may also conveniently be circular. Preferably, the second magnet is located within the boundary of the first annular magnet.

In a preferred embodiment, each plate comprises a plurality of recesses located between the magnet abutment portions, the recesses defining a plurality of said magnetic pole pieces, which extend beyond an inner perimeter of the said first annular magnet and beyond an outer perimeter of the said second magnet.

The said second magnet is also preferably annular and may also conveniently be circular.

Each plate may comprise a plurality of recesses located inwardly of the second magnet abutment portion, the recesses defining a plurality of said magnetic pole pieces, which extend beyond an inner perimeter of the said second, inner annular magnet.

Preferably, each plate comprises a plurality of passage means located outwardly of the first, outer annular magnet, e.g. located at the periphery of each of said plates.

Preferably, the passage means in each plate are defined between adjacent magnetic pole pieces. Each plate may comprise a plurality of recesses about an outer perimeter which define outwardly extending magnetic pole pieces, which extend beyond an outer perimeter of the said magnets.

Each of said plates preferably comprises a plurality of said magnetic pole pieces inclined to the plane of the plate. Preferably, said inclined magnetic pole pieces are inclined towards the other plate.

Preferably, the plates are substantially identical and preferably the plates are generally circular.

Preferably, the regions of magnetic attraction extend axially and/or radially.

In accordance with a second aspect of the present invention, a separator device for removing magnetisable material from a fluid in which said material is suspended, comprises an annular magnet and a pair of metal plates, said magnet having faces of opposite magnetic polarity, each of said plates being disposed in abutment with a respective one of said faces of said magnet, each of said plates having first passage means located outwardly of the annular magnet and second passage means located inwardly of the annular magnet, for the passage of fluid from one side of the plate to the other, and a plurality of projections defining magnetic pole pieces located adjacent to the first and second passage means, the magnetic pole pieces on one of the plates being aligned with the magnetic pole pieces on the other of the plates and forming regions of magnetic attraction to which magnetic material passing through the adjacent first and second passage means is attracted. By providing an annular magnet and passage means located both inwardly and outwardly of the magnet, it is possible to increase the maximum flow through of the separator device and to increase the capacity of the device, i.e. the amount of magnetisable material which can be collected by the device.

Preferably, the annular magnet is circular.

The device preferably comprises a plurality of first passage means and a plurality of said second passage means.

The device also preferably comprises a second magnet located within the first, annular magnet, each of said plates being disposed in abutment with a respective one of said faces of each magnet.

Each of the plates preferably comprises first and second magnet abutment portions in abutment with said first and second magnets respectively. The second passage means are preferably located between the first and second magnet abutment portions.

The second passage means preferably comprises a plurality of recesses located between the magnet abutment portions, the recesses defining a plurality of said magnetic pole pieces, which extend beyond an inner perimeter of the said first annular magnet and beyond an outer perimeter of the said second magnet.

Said second magnet is preferably annular and is preferably also circular. Each plate preferably comprises a plurality of recesses located inwardly of the second magnet abutment portions, the recesses defining a plurality of said magnetic pole pieces, which extend beyond an inner perimeter of the said second, inner annular magnet. Preferably, the device comprises a plurality of passage means located outwardly of the first, outer annular magnet.

There may also be a plurality of first passage means at the periphery of each of said plates.

Preferably, the passage means in the plates are defined between adjacent magnetic pole pieces.

Each plate preferably comprises a plurality of first recesses about an outer perimeter which define outwardly extending magnetic pole pieces, which extend beyond an outer perimeter of the said first, annular magnet. Each of said plates may comprise a plurality of said magnetic pole pieces inclined to the plane of the plate.

Preferably, said inclined magnetic pole pieces are inclined towards the other plate.

Preferably, the plates are substantially identical and preferably they are generally circular.

The present invention also includes a separator for removing ferromagnetic material from a fluid in which said material is suspended, comprising a plurality of separator devices in accordance with the present invention. Preferably, the separator devices are substantially identical.

Preferably, the separator devices are arranged in a stacked formation.

The separator also preferably includes a plurality of said separator devices in abutment with each other.

Preferably, the filter further comprises a housing within which the separator devices are located.

Preferably, the regions of magnetic attraction extend axiaily and/or radially. Preferably, the width of the separator devices corresponds to the width of the portion of the housing which is adapted to receive the separator devices.

By way of example only, a specific embodiment of the present invention will now be described with reference to the accompanying drawings, in which:-

Fig. 1 is a perspective view of an embodiment of magnetic separator device in accordance with the present invention;

Fig. 2 is a longitudinally-sectioned perspective view of the magnetic separator device of Fig. 1 ; Fig. 3 is a longitudinal cross-section through the magnetic separator device of Fig. 1 ;

Fig. 4 is an exploded perspective view of the magnetic separator device of Fig. 1 ; Fig. 5 is a front view of a plate forming part of the magnetic separator device of Fig. 1 ; and

Fig. 6 is a perspective, diametrically-sectioned view of the plate of Fig. 5. Referring to the Figures, a magnetic separator device comprises an outer casing 10 which encloses three identical separator units 12. The casing comprises a first, generally cylindrical tubular portion 14 of internal diameter corresponding to the diameter of the separator units 12 and an internally threaded tubular neck portion 16 of smaller diameter, the two tubular portions being connected by means of a frusto-conical shoulder portion 18. The tubular portion 14 of larger diameter is provided with six identical longitudinally-extending lugs 20 arranged around the exterior periphery at equal angular spacings. The internal surface of the cylindrical portion at the locations corresponding to the external lugs is provided with a longitudinally-extending locating groove 22, as will be explained. The internal face of the shoulder portion is also provided with six longitudinally- extending elongate lugs 24 located at equal angular spacings, for locating the separator units 12, as will be explained.

Each of the separator units 12 comprises an inner annular permanent magnet 28 and an outer annular permanent magnet 30 of larger diameter than the inner annular magnet. The two annular magnets are arranged concentrically with one another and each of the magnets has two identical opposed flat faces, each of which is in contact with a respective one of two identical apertured metal plates 32 which also form part of the separator unit 12. The inner and outer magnets are arranged so that their north poles and south poles are aligned in the same direction, so that each plate 32 is only in contact with two north poles or two south poles. Each of the plates 32 is generally circular and is generally in the form of an outer annular portion 34 connected to a concentrically arranged inner annular portion 36 by means of six radially extending bridge portions 38 located at equal angular spacings around the inner periphery of the outer ring 34 and the outer periphery of the inner ring 36. The bridge portions 38 define six identical equally-angularly spaced apertures 40 between the inner and outer rings 36, 34. As best seen in Fig. 5, the outer periphery of the inner ring 36 is formed into a plurality of trapezoidal lugs 42, three of which project into a respective one of the apertures 40 defined between the inner and outer rings. Each of these lugs is opposed by a similar trapezoidal lug 44 projecting radially inwardly from the inner periphery of the outer ring 34. As best seen in Figs. 1 to 3 and 6, each of the lugs 42, 44 on each plate 32 is inclined inwardly, i.e. towards the other identical plate 32 which, together with the two annular magnets 28, 30, forms the magnetic separator unit. The outer periphery of the outer ring 34 is also provided with twenty four radially outwardly projecting, equally angularly-spaced projections 46. Every fourth projection 46a is rounded and slightly larger and is adapted to be received in a respective one of the longitudinally-extending slots 22 in the inner face of the large diameter portion of the casing. The remaining projections 46 around the periphery of the outer ring 34 are generally trapezoidal and are adapted to abut, or lie immediately adjacent to, the inner surface of the large diameter portion 14 of the casing 10. The projections 46, 46a around the periphery of the outer ring 34 are also slightly inclined towards the other plate 32 forming part of the same magnetic separator unit 12. Recesses 47 are defined between adjacent projections 46.

The radially innermost portion of the inner ring 36 is also provided with six radially inwardly directed equally angularly-spaced trapezoidal projections 48 which are also inclined slightly towards the other plate 32 of the magnetic separator unit. The recesses 50 between adjacent projections from the radially innermost portion of the inner ring are enlarged in that they extend radially outwardly beyond the radially outermost portion of the projection and assume a teardrop-like shape. The overall effect of the radially inwardly directed projections 48 and the teardrop-shaped apertures 50 at the radially innermost portion of the inner ring 36 is to define an innermost aperture 52 having a flower-like shape with a central circular portion and six radially extending "petals".

The diameter and width of the inner and outer magnets 28, 30 correspond to the diameter and width of the inner ring 36 and outer ring 34 of the plates 32. Each separator unit 12 is assembled by positioning the inner and outer magnets 28 30 in contact with inner face of the inner ring 36 and outer ring 34 respectively of one of the plates 32, the two being held together by magnetic attraction. The other plate 32 is then carefully located on top of the magnets with the planar face of the inner and outer rings 36, 34 in contact with the planar faces of the inner and outer annular magnets 28, 30 respectively, the sub-assembly unit 12 thereby being held together by magnetic attraction. It is important to note that during assembly of each magnetic unit 12, the plates are positioned very precisely, so that the larger projections 46a around the periphery of the two plates 32 are in precise angular alignment with one another. As a consequence, each of the inclined projections 42, 44, 46, 48 of each plate 32 will be precisely aligned and opposed to a corresponding projection 42, 44, 46, 48 on the other plate 32 when the magnetic unit 12 is assembled.

As indicated in Fig. 4, three magnetic units 12 are assembled as previously described. The magnetic units 12 are each located within the larger-diameter portion 14 of the casing by aligning each of the six larger radial projections 46a around the periphery of the magnetic unit 12 with a respective one of the six longitudinal locating grooves 22 in the inner face of the larger diameter portion 14 of the casing. The units are arranged so that the poles of the magnets 28, 30 of adjacent units 12 are of like polarity, so that the units 12 will be arranged with the magnets in repulsion, namely N-N, S-S₁ N-N, S-S or S-S, N-N, S-S, N-N polarity formation.

As indicated in Fig. 3, the periphery of the innermost pfate 32 of the innermost magnetic unit 12 abuts the six longitudinally-extending locating lugs 24 on the innermost face of the frusto-conical 18 portion of the casing, thereby locating the unit 12 precisely within the casing. As further seen in Fig. 3, the three magnetic units 12 are stacked one on top of another, such that adjacent units are in abutment with one another. The three magnetic units 12 are held in position within the casing by means of a locking ring 54 which has six identical radially inwardly projecting portions 56 which support the units 42 and spread their weight over a larger area, thereby helping to minimise distortion of the plates of the magnetic units 12. The portions 56 are adapted to be seated in the six longitudinally extending locating grooves 22 and the locking ring 54 is held in position by welding it ultrasonically to the housing 10. . In use, the housing 10 is secured to an inlet pipe by means of the internally threaded female connecting portion 16. Fluid thereby passes into the casing.

As the fluid passes through the casing, it can pass through one of three types of passageway, namely (1 ) through one of the passageways defined by the central flower-shaped aperture 52, (2) through one of the passageways defined in the central apertures 40, between the outer and inner rings 34, 36 of the magnetic units and (3) through one of the passageways defined between the recesses 47 between adjacent projections 46 on the outer periphery of the outer ring 34, and the inner wall of the outer casing 10.

In each case, each passageway is bounded on each side by two opposed pole pieces which define regions of magnetic attraction which extend axially and radially. Therefore as fluid passes through the passageways, magnetisable material within the fluid is attracted into the regions of magnetic attraction between opposed pole pieces and are retained firstly on one of the pole pieces and then on previously-deposited magnetic particles which have built up on the pole pieces. Magnetisable particles continue to build up in those regions until the volume is full. The invention is not restricted to the details of the foregoing embodiment.

For example, although three units 12 have been shown, one or two units or more than three units may be provided, depending on the circumstances. In addition, the or each unit need not contact the casing in which it is located.

Moreover, although permanent magnets have been shown, it would be possible to use electromagnets instead or in addition. One advantage of using electromagnets is that by switching off the electromagnets, the magnetic forces retaining the magnetisable material in the regions of magnetic attraction would disappear, thereby facilitating removal of accumulated magnetisable material from the separator device.

Indeed, although the annular magnets have been shown as one- piece constructions, it would be possible to use an array of magnets to effectively form an annular magnet, if desired. Furthermore, the number and/or shape and/or layout of the projections and recesses of the plates of the separator units may differ from those shown in the specific embodiment. Moreover, the inclined projections need not be inclined, or may be inclined at an angle different to that in the specific embodiment. Indeed, only some of the projections may be inclined, and there may be a plurality of projections inclined at different angles.

Claims

1. A separator device for removing magnetisable material from a fluid in which said material is suspended, comprising a first magnet, a second magnet spaced from said first magnet and a pair of metal plates, each of said magnets having faces of opposite magnetic polarity, each of said plates being disposed in abutment with a respective one of said faces of each magnet, each of said plates having a plurality of passage means for the passage of fluid from one side of the plate to the other and a plurality of projections defining magnetic pole pieces located adjacent to the passage means, the magnetic pole pieces on one of the plates being aligned with the magnetic pole pieces on the other of the plates and forming regions of magnetic attraction to which magnetic material passing through the adjacent passage means is attracted.

2. A separator device as claimed in claim 1 , wherein each of the plates comprises first and second magnet abutment portions in abutment with said first and second magnets respectively.

3. A separator device as claimed in claim 2, wherein at least one of said passage means is located between the first and second magnet abutment portions.

4. A separator device as claimed in claim 3, comprising a plurality of said passageways located between the first and second magnet abutment portions.

5. A separator device as claimed in any of the preceding claims, wherein said first magnet is substantially annular.

6. A separator device as claimed in claim 5, wherein the first annular magnet is circular.

7. A separator device as claimed in claim 5 or claim 6, wherein the second magnet is located within the boundary of the first annular magnet.

8. A separator device as claimed in any of claims 5 to 7, wherein each plate comprises a plurality of recesses located between the magnet abutment portions, the recesses defining a plurality of said magnetic pole pieces, which extend beyond an inner perimeter of the said first annular magnet and beyond an outer perimeter of the said second magnet.

9. A separator device as claimed in any of claims 5 to 8, wherein said second magnet is annular.

10. A separator device as claimed in claim 9, wherein the second annular magnet is circular.

11. A separator device as claimed in claim 9 or claim 10, wherein each plate comprises a plurality of recesses located inwardly of the second magnet abutment portion, the recesses defining a plurality of said magnetic pole pieces, which extend beyond an inner perimeter of the said second, inner annular magnet.

12. A separator device as claimed in any of claims 5 to 11 , comprising a plurality of passage means located outwardly of the first, outer annular magnet.

13. A separator device as claimed in claim 12, comprising a plurality of passage means at the periphery of each of said plates.

14. A separator device as claimed in any of the preceding claims, wherein the passage means in each plate are defined between adjacent magnetic pole pieces.

15. A separator device as claimed in any of the preceding claims, wherein each plate comprises a plurality of recesses about an outer perimeter which define outwardly extending magnetic pole pieces, which extend beyond an outer perimeter of the said magnets.

16. A separator device as claimed in any of the preceding claims, wherein each of said plates comprises a plurality of said magnetic pole pieces inclined to the plane of the plate.

17. A separator device as claimed in claim 16, wherein said inclined magnetic pole pieces are inclined towards the other plate.

18. A separator device as claimed in any of the preceding claims, wherein the plates are substantially identical.

19. A separator device as claimed in any of the preceding claims, wherein the plates are generally circular.

20. A separator device as claimed in any of the preceding claims, wherein the regions of magnetic attraction extend axially and/or radially.

21. A separator device for removing magnetisable material from a fluid in which said material is suspended, comprising an annular magnet and a pair of metal plates, said magnet having faces of opposite magnetic polarity, each of said plates being disposed in abutment with a respective one of said faces of said magnet, each of said plates having first passage means located outwardly of the annular magnet and second passage means located inwardly of the annular magnet, for the passage of fluid from one side of the plate to the other, and a plurality of projections defining magnetic pole pieces located adjacent to the first and second passage means, the magnetic pole pieces on one of the plates being aligned with the magnetic pole pieces on the other of the plates and forming regions of magnetic attraction to which magnetic material passing through the adjacent first and second passage means is attracted.

22 A separator device as claimed in claim 21 , wherein the annular magnet is circular.

23. A separator device as claimed in claim 21 , comprising a plurality of first passage means and a plurality of said second passage means.

24. A separator device as claimed in any of claims 21 to 23, comprising a second magnet located within the first, annular magnet, each of said plates being disposed in abutment with a respective one of said faces of each magnet.

25. A separator device as claimed in claim 24, wherein each of the plates comprises first and second magnet abutment portions in abutment with said first and second magnets respectively.

26. A separator device as claimed in claim 25, wherein the second passage means are located between the first and second magnet abutment portions.

27. A separator device as claimed in claim 25 or claim 26, wherein the second passage means comprises a plurality of recesses located between the magnet abutment portions, the recesses defining a plurality of said magnetic pole pieces, which extend beyond an inner perimeter of the said first annular magnet and beyond an outer perimeter of the said second magnet.

28. A separator device as claimed in any of claims 24 to 27, wherein said second magnet is annular.

29. A separator device as claimed in claim 28, wherein the second annular magnet is circular.

30. A separator device as claimed in claim 28 or claim 29, wherein each plate comprises a plurality of recesses located inwardly of the second magnet abutment portions, the recesses defining a plurality of said magnetic pole pieces, which extend beyond an inner perimeter of the said second, inner annular magnet.

31. A separator device as claimed in any of claims 21 to 30, comprising a plurality of passage means located outwardly of the first, outer annular magnet.

32. A separator device as claimed in claim 31 , comprising a plurality of first passage means at the periphery of each of said plates.

33. A separator device as claimed in any of claims 21 to 32, wherein the passage means in the plates are defined between adjacent magnetic pole pieces.

34. A separator device as claimed in any claims 21 to 33, wherein each plate comprises a plurality of first recesses about an outer perimeter which define outwardly extending magnetic pole pieces, which extend beyond an outer perimeter of the said first, annular magnet.

35. A separator device as claimed in any of claims 21 to 34, wherein each of said plates comprises a plurality of said magnetic pole pieces inclined to the plane of the plate.

36. A separator device as claimed in claim 35, wherein said inclined magnetic pole pieces are inclined towards the other plate.

37. A separator device as claimed in any claims 21 to 36, wherein the plates are substantially identical.

38. A separator device as claimed in any of claims 21 to 37, wherein the plates are generally circular.

39. A separator device as claimed in any of claims 21 to 38, wherein the regions of magnetic attraction extend axially and/or radially.

40. A separator device substantially as herein described with reference to, and as illustrated in, the accompanying drawings.

41. A separator for removing ferromagnetic material from a fluid in which said material is suspended, comprising a plurality of separator devices as claimed in any of the preceding claims.

42. A separator as claimed in claim 41 , wherein the separator devices are substantially identical.

43. A separator as claimed in claim 41 or claim 42, wherein the separator devices are arranged in a stacked formation.

44. A separator as claimed in any of claims 41 to 43, comprising a plurality of said separator devices in abutment with each other.

45. A separator as claimed in any of claims 41 to 44, further comprising a housing within which the separator devices are located.

46. A separator as claimed in claim 45, wherein the width of the separator devices corresponds to the width of the portion of the housing which is adapted to receive the separator devices.