EP0089200A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A high-gradient magnetic separator
Assignee: GEA Process Engineering AS
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Filing: 1983-03-11
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Granted: —
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Expires: 2003-03-11
Abstract
Abstract A high-gradient magnetic separator is provided for filtrating weakly magnetic particles from a fluid in which they are suspended. The fluid is caused to flow through a separation chamber arranged in a gap formed between a pair of opposed pole surfaces of a pair of separate permanent magnetic devices connected with a closed magnetic circuit which includes yoke members. The permanent magnetic devices generate a strong magnetic field in the gap, the magnetic field having a field direction substantially transverse to at least a portion of the flow path of the fluid through the separation chamber. The permanent magnetic devices each include at least one permanent magnetic member having a substantially linear demagnetization curve. A matrix of soft magnetic material is located in the separation chamber to create local magnetic gradients in the magnetic field. The matrix includes strands extending in planes substantially transverse to the magnetic field direction. A major portion of the matrix strands have an orientation transverse to the magnetic field direction and to the main flow direction of the fluid.
Inventors
- 👤 Orla Christensen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 23:38
CPC Classifications
B; B03; B03C; B03C1/00; B03C1/02; B03C1/025; B03C1/031; B03C1/033; B03C1/0332; B03C1/027; B03C1/032; B03C1/034; B03C2201/00; B03C2201/18
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
363 words
A magnetic separator for filtrating magnetizable particles from a fluid, in which they are suspended, comprising a separation chamber (9,22,26,36,37,51) with a fluid inlet (15) and a fluid outlet (16), means for causing said fluid to flow through said separation chamber (9,22,26,36,37,51) along a predetermined flow path from said fluid inlet (15) to said fluid outlet (16), a magnetic circuit comprising a pair of separate permanent magnetic devices interconnected by yoke members (1,2; 29,30; 38-41; 52,53) and arranged with opposed mainly parallel pole surfaces (N, S) (5-8; 34, 35; 44-48, 62-69) on each side of an air gap (3, 31; 42, 43, 50)adapted to receive said separation chamber (9, 22, 26, 36, 37, 51) with a pair of opposed chamber walls (10,11) in magnetic contact with a respective one of said pole surfaces (N, S) for generating inside the separation chamber a magnetic field with a field direction (4,55) substantially transverse to at least a portion of said flow path, and a matrix (12,20) of a soft magnetic material arranged in said separation chamber (9,22,26,36,37,51) to substantially fill up a part of the interior thereof extending between said pair of opposed chamber walls (10,11), said matrix thereby creating local magnetic gradients in said magnetic field, chamber inlet and outlet compartments (13,14) being provided at opposite ends of said matrix-filled part to be positioned outside said gap and communicating with said matrix as well as said fluid inlet (15) and said fluid outlet (16), respectively, to define a main flow direction (19) for said fluid through said matrix (12,20), characterized in that each of said permanent magnetic devices comprises at least one member of a permanent magnetic material having a substantially linear demagnetization curve, that said matrix (12,20) comprises an arrangement of strands of said soft magnetic material extending mainly in planes substantially transverse to said direction, and that said closed magnetic circuit including said permanent magnetic devices and said air gap is proport- tioned as a whole to generate a substantially uniform magnetic field with an intensity by which the individual strands throughout the matrix are substantially driven into a magnetic saturated state, when the separation chamber is positioned in said air gap.
Claim 2
Dependent Claim
363 words
A magnetic separator for filtrating magnetizable particles from a fluid, in which they are suspended, comprising a separation chamber (9,22,26,36,37,51) with a fluid inlet (15) and a fluid outlet (16), means for causing said fluid to flow through said separation chamber (9,22,26,36,37,51) along a predetermined flow path from said fluid inlet (15) to said fluid outlet (16), a magnetic circuit comprising a pair of separate permanent magnetic devices interconnected by yoke members (1,2; 29,30; 38-41; 52,53) and arranged with opposed mainly parallel pole surfaces (N, S) (5-8; 34, 35; 44-48, 62-69) on each side of an air gap (3, 31; 42, 43, 50)adapted to receive said separation chamber (9, 22, 26, 36, 37, 51) with a pair of opposed chamber walls (10,11) in magnetic contact with a respective one of said pole surfaces (N, S) for generating inside the separation chamber a magnetic field with a field direction (4,55) substantially transverse to at least a portion of said flow path, and a matrix (12,20) of a soft magnetic material arranged in said separation chamber (9,22,26,36,37,51) to substantially fill up a part of the interior thereof extending between said pair of opposed chamber walls (10,11), said matrix thereby creating local magnetic gradients in said magnetic field, chamber inlet and outlet compartments (13,14) being provided at opposite ends of said matrix-filled part to be positioned outside said gap and communicating with said matrix as well as said fluid inlet (15) and said fluid outlet (16), respectively, to define a main flow direction (19) for said fluid through said matrix (12,20), characterized in that each of said permanent magnetic devices comprises at least one member of a permanent magnetic material having a substantially linear demagnetization curve, that said matrix (12,20) comprises an arrangement of strands of said soft magnetic material extending mainly in planes substantially transverse to said direction, and that said closed magnetic circuit including said permanent magnetic devices and said air gap is proport- tioned as a whole to generate a substantially uniform magnetic field with an intensity by which the individual strands throughout the matrix are substantially driven into a magnetic saturated state, when the separation chamber is positioned in said air gap.
Claim 3
Dependent Claim
41 words
A magnetic separator as claimed in claim 1, characterized in that a major portion of the matrix strands (12c) have an orientation (12b) transverse to the magnetic field direction (4) as well as said main flow direction (19) for the fluid.
Claim 4
Dependent Claim
33 words
A magnetic separator as claimed in claim 1 or 2, characterized in that the cross-sectional area of the separation chamber (22) transverse to said main flow direction increases in the main flow direction.
Claim 5
Dependent Claim
90 words
A magnetic separator as claimed in claim 1, 2 or 3, characterized in that the separation chamber is formed as a generally box-shaped canister (26, 27) which is arranged to be removable from said cap in a direction perpendicular to the field direction by a linear displacement and is coupled at at least one of two opposite side faces normal to the direction of displacement to a further substantially corresponding canister (28) containing a matrix of soft magnetic material acting as a dummy load for the magnetic gap during displacement.
Claim 6
Dependent Claim
55 words
A magnetic separator as claimed in claim 4, characterized in that three series-connected canisters (26-28) are arranged for linear displacement between first and second positions, in which either of the extreme canisters is disposed in said gap, whereas the other extreme canister is displaced to a position outside the gap for cleaning of said matrix.
Claim 7
Dependent Claim
86 words
A magnetic separator as claimed in any of the preceding claims, characterized in that each of said permanent magnetic devices (29, 20) comprises a stacked ed magnetic series arrangement of at least two members (32, 33) of permanent magnetic materials each having a substantially linear demagnetization curve, said materials having different energy products and intermediate coupling members (34) of a soft magnetic material, said members being stacked in an order of succession corresponding to increasing energy products in the direction towards said pole surfaces (N, S).
Claim 8
Dependent Claim
45 words
A magnetic separator as claimed in claim 6, characterized in that said permanent magnetic members (32, 33, 32a, 33a) are proportioned with cross-sectional areas normal to their internal field direction yielding substantially the same magnetic flux and with thicknesses yielding substantially the same magnetomotive forces.
Claim 9
Dependent Claim
50 words
A magnetic separator as claimed in any of the preceding claims, characterized in that the pole surface (N, S) of each of said permanent magnetic devices is formed by a pole shoe (49) of a magnetic soft material having a decreasing cross-sectional area in the direction towards the air gap.
Claim 10
Dependent Claim
45 words
A magnetic separator as claimed in any of the preceding claims, characterized in that each of said permanent magnetic devices (1, 2; 24, 30; 38-41) comprises at least one member consisting of a permanent magnetic alloy comprising cobalt and at least one rare earth metal.
Claim 11
Dependent Claim
17 words
A magnetic separator as claimed in claim 9, characterized in that said rare earth metal is samarium.
Claim 12
Dependent Claim
62 words
A magnetic separator as claimed in any of the preceding claims, characterized in that at least two pairs of permanent magnetic devices (38, 39; 40, 41) are arranged in series to define at least two parallel air gaps (42, 43) to receive respective one of a corresponding number of separation chambers (36, 37) with substantially parallel main flow directions for said fluid.
Claim 13
Dependent Claim
29 words
A magnetic separator as claimed in claim 11, characterized in that all permanent magnetic devices (38-41) in said series arrangement are magnetically connected through a common yoke (44, 48).
Claim 14
Dependent Claim
180 words
A magnetic separator as claimed in any of claims 1-5, characterized in that each of said permanent magnetic devices (52, 53) comprises a pole shoe member (54, 70) of a magnetic soft material forming one of said pole surfaces (56, 73) , a first permanent magnetic member (57, 74) arranged in magnetic contact with a side of said pole shoe member (54, 70) opposite said gap (50) and parallel to said pole surface (56, 73), said member having a direction of magnetization generally normal to said pole surface (56, 73), and second magnetic members (58-61; 75-77) extending on each side of said pole shoe member (54, 70) mainly transverse to saidpole surface (56, 73) and having a direction of magnetization substantially perpendicular to that of said first member (57, 74), the surfaces of said first and second members facing said pole shoe member (54, 70) having all the same magnetic polarity, said first magnetic member (57, 74) being in magnetic contact with said second magnetic members (58-61; 75-77) to provide a leakage-free enclosure for said pole shoe member (54, 70).
Claim 15
Dependent Claim
88 words
A magnetic separator as claimed in claim 13, characterized in that said pole shoe member (70) has a substantially T-shaped cross-sectional profile with a leg (71) projecting from a base plate (72) and with the free end of said leg (71) forming said pole surface (73) and said first magnetic member (74) arranged in magnetic contact with the opposite end of said profile against said base plate (72), said second magnetic members (75-77) being arranged parallel to said leg (71) at either side of said base plate (72).
Claim 16
Dependent Claim
30 words
A magnetic separator as claimed in claim 14, characterized in that each of said second magnetic members (75-77) extends beyond said base plate (72) in the direction towards the gap.
Claim 17
Dependent Claim
27 words
A magnetic separator as claimed in claim 15, characterized in that each of said second members (75-77) has a length corresponding to that of said leg (71).
Claim 18
Dependent Claim
49 words
A magnetic separator as claimed in claim 13, characterized in that said pole shoe member (54) has a uniform cross-sectional area transverse to the field direction (55) therein, and that said second members (58-61) are arranged in direct contact with the side faces of the pole shoe member (54).
Claim 19
Dependent Claim
28 words
A magnetic separator as claimed in any of claims 13 to 17, characterized in that said first and second permanent magnetic members (57-61; 74-77) are made of ferrite.
References Cited (Backward Citations)
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