US3770629A

US3770629A - Multiple matrix magnetic separation device and method

Info

Publication number: US3770629A
Application number: US00151765A
Authority: US
Inventors: J Nolan; P Marston; L Lontai
Original assignee: MAGNETIC ENG ASS Inc
Current assignee: SALA MAGNETICS Inc A CORP OF DEL
Priority date: 1971-06-10
Filing date: 1971-06-10
Publication date: 1973-11-06
Anticipated expiration: 1990-11-06

Abstract

A MULTIPLEX MATRIX MAGNETIC SEPARATION DEVICE AND METHOD INCLUDING ELECTROMAGNETIC COIL MEANS FOR PROVIDING A MAGNETIC FIELD VOLUME IN THE SPACE ENCOMPASSED BY THE ELECTROMAGNETIC COIL MEANS, A PLURALITY OF MAGNETIC MATRICES STACKED WITHIN THE SPACE ENCOMPASSED BY THE ELECTROMAGNETIC COIL MEANS, A PLURALITY OF FLOW CONTROL MEANS DISPOSED BETWEEN THE MAGNETIC MATRICES AND ONE ON EACH END OF THE STACK OF THE MAGNETIC MATRICES, EACH OF THE FLOW CONTROL MEANS DISPOSED BETWEEN THE MAGNETIC MATRICES INCLUDING A DISTRIBUTION NETWORK FOR DISTRIBUTING THE SLURRY WHICH UNDERGOES MAGNETIC SEPARATION TO THE CORRESPONDING ADJACENT MAGNETIC MATRIX AND A COLLECTION NETWORK FOR COLLECTING THE SLURRY FROM THE OTHER CORRWSPONDING ADJACENT MAGNETIC MATRIX AFTE THE SLURRY HAS UNDERGONE SEPARATION, ONE OF THE FLOW CONTROL MEANS AT ONE END OF THE STACK OF MAGNETIC MATRICES INCLUDING ONE OF THE DISTRUBUTION AND COLLECTION NETWORKS AND THE OTHER OF THE FLOW CONTROL MEANS AT THE OTHER END OF THE STACK INCLUDES THE OTHER OF THE NETWORKS, INLET MEANS FOR DELIVERING SLURRY WHICH IS TO UNDERGO SEPARATION TO THE DISTRIBUTION NETWORKS AND OUTLET MEANS FOR RECEIVING FROM THE COLLECTION NETWORKS SLURRY THAT HAS UNDERGON SEPARATION.

Description

Nov. 6, 1973 J. J. NOLAN 3,770,629

MULTIPLE MATRIX MAGNETIC SEPARATION DEVICE AND METHOD Filed June l0, 1971 2 Sheets-Sheet l [14 r/12 L0 m 22% 2o) /14 flea 156 fla 'MFQIIWZ] (460 0 O 40/ //x/ f NOV. 6, 1973 J, J, NOLAN 3,770,629

MULTIPLE MATRIX MAGNETTC SEPARATION DEVTCE AND METHOD Filed June 10, 1971 2 Sheets-Sheet 2 /JHTH 12a United States Patent O 3,770,629 MULTIPLE MATRIX MAGNETIC SEPARATION DEVICE AND METHOD John J. Nolan, Randolph, and Peter G. Marston, East Gloucester, Mass., and Laszlo M. Lontai, South Bend, Ind., assignors to Magnetic Engineering Associates, Inc., Cambridge, Mass.

Filed June 10, 1971, Ser. No. 151,765 The portion of the term of the patent subsequent to Dec. 14, 1988, has been disclaimed Int. Cl. B01d 17/06 U.S. Cl. 210-42 20 Claims ABSTRACT OF THE DISCLOSURE A multiplex matrix magnetic separation device and method including electromagnetic coil means for providing a magnetic iield volume in the space encompassed by the electromagnetic coil means, a plurality of magnetic matrices stacked within the space encompassed by the electromagnetic coil means, a plurality of ow control means disposed between the magnetic matrices and one on each end of the stack of the magnetic matrices, each of the ow control means disposed between the magnetic matrices including a distribution network for distributing the slurry which undergoes magnetic separation to the corresponding adjacent magnetic matrix and a collection network for collecting the slurry from the other corresponding adjacent magnetic matrix after the slurry has undergone separation, one of the iiow control means at one end of the stack of magnetic matrices including one of the distribution and collection networks and the other of the ow control means at the other end of the stack includes the other of the networks, inlet means for delivering slurry which is to undergo separation to the distribution networks and outlet means for receiving from the collection networks slurry that has undergone separation.

FIELD OF INVENTION This invention relates to a magnetic separation device and method for separating materials of differing magnetic susceptibility, and more particularly to such a magnetic separation device having multiple magnetic matrices.

SUMMARY OF INVENTION The invention features a multiple matrix magnetic separation device having an electromagnetic coil means for providing a magnetic field volume in the space encompassed by the electromagnetic coil means. There are a plurality of magnetic matrices stacked within the space encompassed by the electromagnetic coil. A plurality of flow control means are disposed between the magnetic matrices and one on each end of the stack of magnetic matrices. Each of these flow control means disposed between the magnetic matrices includes a distribution network for distributing the slurry to undergo magnetic separation to its corresponding adjacent magnetic matrix and a collection network for collecting the slurry from its other corresponding adjacent magnetic matrix after the slurry has undergone separation. The flow control means at one end of the stack of magnetic matrices includes one of the distribution and collection networks and the flow control means at the other end of the stack includes the other network. There are inlet means for delivering slurry to undergo separation to the distribution networks and outlet means for receiving from the collection networks slurry that has undergone separation.

DISCLOSURE OF PREFERRED EMBODIMENT Other objects, features and advantages will occur from the following description of a preferred embodiment and the accompanying drawings, in which:

FIG. l is a cross sectional diagrammatic elevational view taken on a diametric plane through a cylindrical multiple matrix separation device according to this invention.

FIG. 2 is an elevational diagrammatic view of the device of FIG. 1 with the ferromagnetic return frame omitted and with portions of parts of the device broken away to show the distribution networks and collection networks in the various flow control members and the inlet and outlet means which supply those networks.

FIG. 3 is a cross sectional plan view of a iiow control member taken along line 3-3 of FIG. 2 exposing a typical distribution network and collection network.

FIG. 4 is a view similar to FIG. l depicting a portion of the machine to the right of the center line showing an alternative embodiment of the invention.

The invention may be embodied in a multiple matrix magnetic separation device including a cylindrically shaped electromagnetic coil within which is disposed a plurality of magnetic matrices with interstitial iiow control members; the matrices are generally arranged in a stack and there is an additional flow control member at the top of the stack and at the bottom of the stack. Each of the interstitial ow control members includes a distribution network for distributing to its corresponding magnetic matrix the slurry which is to undergo magnetic separation and a collection network for collecting the slurry from its other corresponding magnetic matrix after the slurry has undergone separation. The flow control member at one end of the stack contains either a distribution network or a collection network and the flow control member at the other end of the stack contains the other of those networks. In the preferred embodiment the ow control members should be of ferromagnetic material. If, however, their thickness in the direction of the field is small compared to the thickness of the matrices they may be of a low permeability material and still satisfy the requirements of this invention. Provision is made for connection of an inlet means to supply slurry to each of the distribution networks and outlet means to remove the slurry from each of the collection networks. The magnetic matrix generally includes a ferromagnetic material such as steel wool, steel balls, or steel tacks enclosed in a canister which may be made of a stainless steel or other material of low magnetic permeability. The electromagnetic coil, multiple matrices and flow control members may be enclosed in a ferromagnetic return frame to increase the eiiiciency of the magnetic circuit. The technique of stacking magnetic matrices adjacent to each other to achieve a predetermined matrix area instead of using a single matrix of the same area may be employed to reduce the volume of the ferromagnetic return frame surrounding the coil. Each additional layer used in the stack to accomplish a particular area requirement reduces the diameters of the top and bottom portions of the return frame, the intermediate cylindrical portion and the electromagnetic coil and increases the length of the coil and cylindrical portion of the frame in the direction of slurry flow. The number of matrices used to accomplish a particular process capacity should Ibe optimized for maximum efficiency and in some cases it may even be determined that a single layer is the optimum configuration. But in those configurations wherein two or more matrices arranged in a stack provide greater efficiency than a single large matrix the multiple matrix separation device of this invention becomes a particularly useful and efficient device.

In alternative configurations, instead of one electromagnetic coil coextensive with all of the matrices, a number of electromagnetic coils may be used. For example, a number of electromagnetic coils equal in number to the number of matrices may be used. -Each electromagnetic coil is associated with a particular one of the magnetic matrices and the ow control members may be extended between and radially beyond the coils to provide an alternative means for connecting the distribution and collection networks with inlet and outlet means, respectively.

The electromagnetic coil or coils used in a device are not limited to the conventional variety: they may be superconducting or even cryogenic electromagnetic coils. If, for example, superconducting electromagnetic coils are employed, the costs of electric power used to generate these magnetic fields is no longer a critical factor and the added efficiency contributed by the return frame may not be signiticant. The return frame might still be used to achieve better magnetic field distribution, especially for large diameter to height ratio systems. However, if in any particular separation operation the optimum design produces a multiple matrix stacked array that is sufficiently narrow, i.e. is of a small radius, so that the increase of eliciency and field uniformity contributed by the return frame is no longer significant, the return frame may be omitted.

There is shown in FIG. 1 a multiple matrix magnetic separation device including a ferromagnetic return irame 12 consisting of disc-shaped pole pieces or pole sections, upper and

lower portions

14 and 16, and a cylindrical intermediate portion 18 within which is disposed electromagnetic coil 20 which is cylindrical in shape. The pole sections, upper and

lower portions

14 and 16, are ferromagnetic members of substantial mass located closely adjacent the matrices.

Pole portions

14 and 16 by their size and positions provide a low reluctance path for the magnetic field whereby the major portion of the magnetomotive force (MMF) provided by coil 20 is presented by the

pole portions

14 and 16 across the matrices and MMF drops in the rest of the circuit are minimized. The presence of the pole portions, particularly the parts directly above and below the matrices, ser-ve to concentrate the field and direct it through the matrices parallel to the direction of slurry flow. Centrally located and encompassed by electromagnetic coil 20 is a multiple matrix array 22 which includes in this specific embodiment four steel |wool

magnetic matrices

24, 26, 28, and 30, each of which is contained in a

stainless steel canister

32, 34, 36, and 3'8, respectively. Between each pair of these matrices are

ow control members

40, 42, and 44, each of which contains a distribution network and a collection network, not shown in FIG. 1, but depicted in detail in FIG. 2. At each end of the array 22 are two more

ow control members

46 and 48, each of which includes only one network, either a collection network or a distribution network, not here shown, but which appear in detail in FIG. 2. 'Ihe determination of which type of network each of

ow control members

46 and 48 includes depends upon the direction of flow of the slurry through the matrices: if the ow enters the matrices from the lower side and leaves them from the upper side, then ow control member 46 contains a distribution network and iow control member 48 contains a collection network. If the slurry passes through in the other direction, the converse is true, as will be apparent from the description of FIG. 2. Inlet and outlet means for delivering and receiving slurry to and from the distribution and collection networks, respectively, are not shown in FIG. 1, but are shown in FIG. 2. The magnetic eld 50 provided by electromagnetic coil 20 passes generally vertically through array 22 in a direction generally parallel to the direction of slurry ow through the matrices. 'Ihe ferromagnetic return frame 12 which is useful to promote efficient use of the magnetic field 50 when the diameter of the coil is large and its length in the direction of the slurry liow is small, becomes less so as the multiple matrix device of this invention tends toward a smaller radius configuration: a coil longer in the direction of slurry flow but smaller in terms of radius. Such a reduction inuences the magnetic design such that in some cases the return frame, particularly the portion 18, may become of insubstantial value.

Flow control member 44, FIG. 2, includes a distribution network 52 that feeds slurry to matrix 30. Distribution network 52 includes a plurality of radial extending passages 54 which extend outward from the center of the member like spokes of a Wheel and are fed by a central chamber 56 which is supplied by inlet pipe S8. Each of passages 54 includes a plurality of ports 60, each of which communicates with the lower edge of matrix 30, through ports 60' in canister 38. Suitable sealing between the canisters and ow members is provided to prevent leakage. Sealing may be accomplished by cylinders surrounding the matrix and between the flow control members. In any event, suitable sealing is provided in array 22 to prevent leakage, but has been omitted here because sealing techniques are known in the art and their depiction here would not contribute to a better understanding of the invention. Similarly, flow control member 42 includes distribution network 61 having ports 62 disposed on radial passages 64 fed by annular channel 66 which in turn is supplied with slurry by inlet pipe 68; flow control member 40 includes distribution network 69 having ports 70 in radial passages 72 fed by annular channel 74 supplied with slurry by inlet pipe 76. Since the llow of slurry through the matrices of array 22 has been assumed as upward from bottom to top, ilow control member 46 includes only a distribution network 78 Whose ports in radial passages 82 are fed by annular channel 84 supplied with slurry by inlet pipe 86.

Inlet pipes

58, 68 and 76 are accommodated in bore 88 of ow control member 46 and sealing sleeve 90 in matrix 24.

lInlet pipes

58 and 68 are accommodated as well by bore 92 in flow control member 40 and sealing sleeve I94 in matrix 26; and piupe 58 is accommodated by bore 916 in flow control member 42 and sealing sleeve 98 in matrix 28. Ports l62, 70 and 80 in ow control members correspond with ports 62', 70 and 80 in

canisters

36, 34, and 32, respectively.

IEach of

flow control members

40, 42 and 44 also includes a

collection network

100, 102, 104 having

ports

106, 108, connected to

radial passages

112, 114, 116 which discharge into

annular channels

118, 120, 122 which expel the slurry through

outlet pipes

124, 126, 128, all respectively. Since the direction of slurry flow through the array 22 is upward from bottom to top, ow control member 48 also includes a collection network having ports 132 connected with radial passages 134 which discharge into annular chamber 136 that removes the slurry through outlet pipe 138. Ports 106, l108, 110 and 132 in

ilow control members

40, 42, 44 and 48 correspond with

ports

106', 108', 110 and 132 in

canisters

32, 34, 36 and 38, respectively.

Although in the specific embodiment shown in FIG. 2 the slurry is fed into the matrices by inlet pipes which enter in the center of the array and is removed by outlet pipes which are connected to the periphery of the array this is not a limitation of the invention: the positions of the inlet and outlet pipes may as Well be reversed, or some of the inlet pipes may be at the center and some at the periphery and likewise with the outlet pipes, or all pipes could be at the center or at the periphery. Various other delivery removal schemes may be used without departing from the scope of the invention.

Inlet pipes

58, 68, 76, 86 are connected in parallel to a source of raw feed and

outlet pipes

124, 126, 128 and 138 are connected in parallel to an output line or other receptacle.

The distribution network 61 and collection network 102 in flow control member 42 is shown more completely in FIG. 3. Distribution network 61 includes eight passages 64, each of which contains six ports 62 that feed slurry to magnetic matrix 28. Each of passages 64 extends radially outwardly from annular channel 66 which is concentric with and located near the center of ilow control member 42. Annular channel 66 receives slurry from inlet pipe 68 disposed in bore 92.

Collection network 102 includes a plurality of passages 114 extending radially inwardly from annular channel 120 which remove the slurry through outlet pipe 126. Each passage 114 includes six ports 108.

The distribution and collection networks shown in FIGS. 2 and 3 are but one configuration for such networks and many other designs and variations are possible. For example, ports may be added to

annular channels

66 and 120. The channels and passages may be progressively reduced in diameter as the distance from the inlet and outlet pipes increases: the diameter of the channel 66 and passages 64 may be reduced as the distance from the inlet pipe 68 increases. Similarly, the passages 64 and channel 66 may equally as well operate as a collection network and the passages 114 and channel 120 operate as the distribution network. In addition, the generally radial design pictured in FIG. 3 is not a necessity to either the distribution or collection networks as any suitable rectilinear, curvilinear, or combinations of paths and shapes may be used.

The magnetic field 50', FIG. 4, need not be supplied by one single electromagnetic coil, as shown in the embodiment of FIG. 1, but rather may be supplied by a plurality of

electromagnetic coils

150, 152, 154, and 156, stacked in the same manner as the

matrices

24, 26, 28 and 30. In such an arrangement, the

ve control members

40, 42, 44, 46, and 48 may be extended between and beyond

coils

150, 152, 154, and 156 and directly connected to

pipes

158, 160, 162, 164, and 166 which may, for example, be the inlet pipes, and a second set of similar pipes, not shown, may serve as the outlet pipes.

Other embodiments will occur to those skilled in the art and are within the following claims:

What is claimed is:

1. A multiple matrix magnetic separation devlce comprising:

a plurality of separate magnetic matrices in a stacked array, the boundaries between said separate magnetic matrices in said stacked array being transverse to the direction of ow through said matrices of slurry to undergo magnetic separation;

electromagnetic coil means surrounding said stacked array of matrices for providing a magnetic eld volume in the space occupied by said stacked array of matrices;

a plurality of flow passage means disposed between the magnetic matrices and one on each end of the stack of said magnetic matrices; each of said flow passage means disposed between said magnetic matrices including a distribution network for distributing the slurry to undergo magnetic separation to its corresponding said magnetic matrix and a collection network for collecting the slurry from its other magnetic matrix after the slurry has undergone separation, one of said flow passage means at one end of the stack of said magnetic matrices including a one of said distribution and collection networks and said ow passage means at the other end of the stack including the other of said networks; and

inlet means for delivering slurry to undergo separation to said distribution networks and outlet means for receiving from said collection networks slurry that has undergone separation.

2. The device of claim 1 in which said electromagnetic coil means includes a plurality of coils one associated with each of said matrices.

3. The device of claim 2 in which said ow control means extend beyond the inner periphery of said coils.

4. The device of claim 2 in which said ow control means extend beyond the outer periphery of said coils.

5. The device of claim 1 in which said ilow control means extend generally to the inner periphery of said electromagnetic coil means. y

6. The device of claim 1 in which said ow control means include ferromagnetic material.

7. The device of claim 1 in which each of said networks includes a plurality of ports communicating with its associated said magnetic matrix and conduit means for connecting said ports to the appropriate one of said inlet and outlet means.

8. The device of claim 1 in which said electromagnetic coil means is annular and said matrices present a circular area to the slurry flow.

9. The device of claim 1 further including a ferromagnetic return frame proximate said electromagnetic coil means including a rst portion adjacent one side of said coil means and extending over said space encompassed by said electromagnetic coil means and a second portion adjacent the other side of said electromagnetic coil means and extending over said space.

10. The device of claim 9 in which said return frame further includes a third portion extending about the external periphery of said electromagnetic coil means between said rst and second portions.

11. A method of separating material of different magnetic susceptibility comprising: supplying slurry to undergo separation to inlet means, directing the slurry to a plurality of distribution networks in a plurality of flow passage means; distributing the slurry from each of said distribution networks into a respective associated one of a plurality of separate magnetic matrices in a stacked array the boundaries between said matrices in said stacked array being transverse to the direction of flow through said matrices of said slurry; providing from electromagnetic coil means surrounding said stacked magnetic matrices, a magnetic field in said stacked matrices; collecting the slurry that has undergone separation from each of said matrices in a respective associated one of a plurality of collection networks in said ow passage means; and introducing the slurry that has undergone separation from said collection networks into outlet means for removing said slurry that has undergone separation.

12. The method of claim 11 in which said electromagnetic coil means includes a plurality of coils one associated with each of said matrices.

13. The method of claim 12 in which said flow control means extend beyond the inner periphery of said coils.

14. The method 0f claim 12 in which said ilow control means extend beyond the outer periphery of said coils.

15. The method of claim 11 in which said flow control means extend generally to the inner periphery of said electromagnetic coil means.

16. The method of claim 11 in which said flow control means include ferromagnetic material.

17. The method of claim 11 in which each of said networks includes a plurality of ports communicating with its associated said magnetic matrix and conduit means for connecting said ports to the appropriate one of said inlet and outlet means.

18. The method of claim 11 in which said electromagnetic coil means is annular and said matrices present a circular area to the slurry flow.

19. The method of claim 11 further including a ferromagnetic return frame proximate said electromagnetic coil means including a first portion adjacent one side of said coil means and extending over said space encompassed by said electromagnetic coil means and a second portion adjacent the other side of said electromagnetic coil means and extending over said space.

7 8 20. The method of claim 19 in which said return frame 3,633,751 1/ 1972 Stevens 210222 further includes a third portion extending about the ex- 3,627,678 12/ 1971 Marston 210--222 ternal periphery of said electromagnetic coil means be- 3,581,898 6/ 1971 Tyrrell 210-222 tween said rst and second portions. FOREIGN PATENTS References Cited 5 801,003 9/ 1958 Great Britain 210-223 UNITED STATES PATENTS FRANK A. SPEAR, JR., Primary Examiner r T. A. GRANGER, Assistant Examiner 2,149,764 3/1939 Frei 210*223 10 U S C1 X R 2,329,893 9/1943 Girard 210-222 2,317,774 4/1943 Kick et al. 210-222 209-232; 21o-222 3,567,026 3/1971 Holm 210--222