DEVICE AND METHOD FOR MAGNETIC SEPARATION

Abstract

The invention relates to an apparatus for removing magnetizable particles in a substance, the apparatus comprising a magnetic separation chamber for filtering magnetizable particles and flocs from the substance, wherein the magnetic separation chamber comprises a first housing that defines a first space through which the substance can flow, as well as at least one first magnet of which a first magnetic field reaches into the first space, and which first magnet is located within a first holder that has an interface with the first space; and a flocculation chamber for inducing flocculation of the particles in a substance, the flocculation chamber being in fluid connection with the magnetic separation chamber; wherein the magnetic separation chamber is located downstream of the flocculation chamber, and wherein the flocculation of the magnetizable particles results in magnetizable flocs, and the magnetic field of the first magnet causes the magnetizable flocs to be attracted towards the first magnet, thereby removing the flocs of magnetizable particles from the substance.

Claims

1. An apparatus for removing magnetizable particles in a substance, the apparatus comprising: a magnetic separation chamber for filtering magnetizable particles and flocs from the substance, wherein the magnetic separation chamber comprises a first housing that defines a first space through which the substance can flow, as well as at least one first magnet of which a first magnetic field reaches into the first space, and which first magnet is located within a first holder that has an interface with the first space; and a flocculation chamber for inducing flocculation of the particles in the substance, the flocculation chamber being in fluid connection with the magnetic separation chamber, characterized in that the flocculation chamber comprises a second housing that defines a second space through which the substance can flow, as well as at least one second magnet which is located within a second holder that has an interface with the second space, wherein each second holder comprises a tube that is closed at an end that extends into the second space, wherein a second magnetic field of said second magnet reaches into the second space, and wherein the magnetic field of the second magnet causes the magnetizable particles to be attracted to each other, thereby undergoing flocculation and forming flocs in the flocculation chamber, wherein the magnetic separation chamber is located completely downstream of the flocculation chamber wherein the flocculation chamber is arranged immediately adjacent to the magnetic separation chamber, and wherein the flocculation of the magnetizable particles in the flocculation chamber results in magnetizable flocs, and the magnetic field of the first magnet causes the magnetizable flocs to be attracted towards the first magnet, thereby removing the flocs of magnetizable particles from the substance.

2. The apparatus of claim 1, wherein: the second holder of the second magnet has an oval cross section, wherein a major axis of the oval cross section is directed in the downstream direction; and/or each first holder (118) comprises a tube that is closed at an end that extends into the first space (114) so that magnetizable particles or flocs may accumulate on the outside of the first holder

3. (canceled)

4. The apparatus of claim 1, wherein the flocculation chamber and the magnetic separation chamber are integrally formed.

5. The apparatus of claim 1, wherein a cross section of the second holder of the second magnet has a greater dimension in the downstream direction with respect to a dimension in a direction transverse to the downstream direction.

6. The device of claim 1, wherein the magnetic separation chamber has a connection flange through which the substance can flow, wherein the flocculation chamber has a connection through which the substance can flow, the flocculation chamber and magnetic separation chamber being in fluid connection through said connection flanges, and wherein the connection flange of the magnetic separation chamber is adjacent and connected to the connection flange of the flocculation chamber.

7. The apparatus of claim 1, wherein the first and/or second magnets have a rod shape, and which first and/or second magnets have a releasable fit into the first and/or second holder.

8. The apparatus of claim 1, wherein the first and/or second holder has a top side outside of the first and/or second space from which each tube extends into the first and/or second space, respectively.

9. The apparatus of claim 1, wherein the first and/or second magnets are connected to a moving mechanism to move the first and/or second magnet with respect to the first and/or second space, respectively.

10. The apparatus of claim 1, wherein the housing of the flocculation chamber is provided with an inlet part that is connectable to a conduit system through which the substance flows, and wherein the housing of the magnetic separation chamber is provided with an outlet part that is connectable to the conduit system.

11.-12. (canceled)

13. The apparatus of claim 1, wherein the first space of the magnetic separation chamber defines a spatial volume which is greater than the spatial volume defined by the second space of the flocculation chamber.

14. The apparatus of claim 1, wherein: a longitudinal direction of the first and/or second holders is substantially perpendicular, parallel, or a combination thereof to a downstream direction from the flocculation chamber towards the magnetic separation chamber; and/or a direction of the first and/or second magnetic fields is substantially perpendicular, parallel, or a combination thereof to the downstream direction

15.-19. (canceled)

20. The apparatus of claim 1, wherein the housing of the magnetic separation chamber further comprises a removable attachment, wherein the magnets of the magnetic separation chamber are connected to the attachment, and wherein the housing further comprises holders for holding the magnets.

21. Device for pre-magnetizing magnetizable particles, the device comprising a flocculation chamber for inducing flocculation of the particles in a substance, the flocculation chamber being fluidly connectable to a magnetic separation chamber located downstream from the flocculation chamber, wherein the flocculation chamber comprises a housing that defines a space through which the substance can flow, as well as at least one magnet of which a magnetic field reaches into the space, and which magnet is located within a holder that has an interface with the space, said holder comprising a tube that is closed at an end that extends into the space; wherein a cross section of the holder of the magnet has a greater dimension in the downstream direction with respect to a dimension in a direction transverse to the downstream direction; and wherein the magnetic field of the magnet causes the magnetizable particles to be attracted to each other, thereby undergoing flocculation and forming flocs.

22. (canceled)

23. The device of claim 21, further comprising: an inlet part that is connectable to a conduit system through which the substance flows; and one or more flanges for connection to the magnetization chamber.

24. (canceled)

25. The device of claim 23, wherein the housing comprises a flange on a first side, for connecting to an inlet part that is connectable to a conduit system and a flange on a second, opposite side, for connecting to the magnetic chamber;

26. A method of removing magnetizable particles from a substance, the method comprising the steps of inducing flocculation of the magnetizable particles in the substance to produce flocs by providing a second magnetic field applied in a flocculation chamber, wherein the flocculation has a connection flange through which the substance can flow, wherein the flocculation chamber comprises a housing that defines a second space through which the substance can flow, as well as at least one magnet which is located within a holder that has an interface with the space, wherein each holder comprises a tube that is closed at an end that extends into the space, wherein a magnetic field of said magnet reaches into the space, and wherein the magnetic field of the magnet causes the magnetizable particles to be attracted to each other, thereby undergoing flocculation and forming flocs in the flocculation chamber; providing a first magnetic field in a magnetic separation chamber in order to magnetize the flocs and single particles, wherein the magnetic separation chamber is arranged immediately adjacent to and completely downstream of the flocculation chamber, and wherein the magnetic separation chamber has a connection flange through which the substance can flow, the flocculation chamber and magnetic separation chamber being in fluid connection through said connection flanges, wherein the connection flange of the magnetic separation chamber is adjacent and connected to the connection flange of the flocculation chamber; conveying the substance from the flocculation chamber through the magnetic separation chamber to remove the magnetized flocs and single particles from the substance.

27. The method of claim 26, wherein the step of inducing flocculation comprises providing a second magnetic field applied in the flocculation chamber.

28. The method of claim 26, further comprising the step of reducing the flow velocity of the substance prior to and/or during the step of forming flocs and during the step of separation in the magnetic separation chamber.

29. The method of claim 26 further comprising cleaning the magnetic separation chamber and/or the flocculation chamber, wherein said cleaning any of the chambers comprises removing the respective magnets from the chamber.

30. (canceled)

31. The method of claim 26 using the apparatus of claim 1 for removing magnetizable particles in the substance.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] FIG. 1 shows a top view of an apparatus for magnetic separation according to the invention.

[0061] FIG. 2 shows a cross section along line A-A of the apparatus of FIG. 1.

[0062] FIG. 3 shows a perspective view of a device for pre-magnetizing magnetizable particles according to the invention.

[0063] FIG. 4 shows a top view of a magnetic separation system comprising the apparatus of FIG. 1 including the bypass system.

[0064] FIGS. 5a-5f show a schematic view of a magnetic separation process and a cleaning process.

[0065] FIG. 5a shows a schematic view of a magnetic separation system according to the invention during active filtration prior to a cleaning process.

[0066] FIG. 5b shows a schematic view of the magnetic separation system according to the invention during a first step of the cleaning process.

[0067] FIG. 5c shows a schematic view of the magnetic separation system according to the invention during a second step of the cleaning process.

[0068] FIG. 5d shows a schematic view of the magnetic separation system according to the invention during a spray cleaning step of the cleaning process.

[0069] FIGS. 6a-6b shows a schematic view of a magnetic separation system according to the invention, wherein the holders, magnets, and magnetic fields are arranged substantially parallel to the flow direction.

[0070] FIGS. 7a-7c shows a further schematic view of a magnetic separation system according to the invention, wherein the holders, magnets, and magnetic fields are arranged substantially perpendicular to the flow direction, in which a draining outlet is visible.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0071] FIG. 1 shows a perspective view of an apparatus 100 for removing magnetizable particles in a substance, being a part of a magnetic separation system. FIG. 2 shows a cross section along line A-A of the apparatus of FIG. 1. The term substance as used herein refers to any one of a liquid, gas, fluid, suspension, dry substance, or a mixture thereof. An exemplary embodiment is described with respect to a fluid substance, such as a liquid or gas, but it will be within the scope that a dry substance can be processed with the apparatus.

[0072] The apparatus 100 is a magnetic separator or filtration system comprising a magnetic separation or filter chamber 110 for filtering magnetizable particles and flocs from the substance, and a flocculation chamber 130, possibly comprised in a pre-magnetizing device 150, for inducing flocculation of the particles in the substance.

[0073] The magnetic separation chamber 110 comprises a first housing 112 that defines a first space 114 through which the substance can flow. The magnetic separation chamber further comprises a plurality of first magnets 116 of which a first magnetic field reaches into the first space 114. The first magnets 116 are each located within first holders 118 that have an interface 120 with the first space 114.

[0074] The flocculation chamber 130 comprises a second housing 134 that defines a second space 136 through which the substance can flow. In addition, the flocculation chamber 130 comprises a plurality of second magnets 138 of which second magnetic fields reach into the second space 136. The second magnets 138 are each located within second holders 140 that each have an interface 142 with the second space 136. The magnetic fields of the second magnets 138 causes the magnetizable parts in the substance to be attracted to each other, thereby undergoing flocculation and forming flocs.

[0075] The flocculation chamber 130 is in fluid connection with the magnetic separation chamber 110 through connection flanges 122 and 132, respectively, placing the magnetic separation chamber 110 and the flocculation chamber 130 adjacent to each other.

[0076] The magnetic separation chamber 110 is located downstream of and adjacent to the flocculation chamber 130. The flocculation of the magnetizable particles by means of pre-magnetization, results in magnetizable flocs. The magnetic field of the first magnets 116 causes the magnetizable flocs to be attracted towards the first magnets 116 thereby removing the flocs of magnetizable parts from the substance. The first space of the magnetic separation chamber defines a spatial volume which is greater than the spatial volume defined by the second space of the flocculation chamber, and which second space spatial volume is greater than the spatial volume of the conduit system. The spatial volume of a chamber defines the residence time of the substance in the chamber.

[0077] The second housing 134 of the flocculation chamber 130 is provided with an inlet part 144 that is connectable to a conduit system 106, see FIG. 4, through which the substance flows. The first housing 112 of the magnetic separation chamber 110 is provided with an outlet part 124 that is connectable to the conduit system 106.

[0078] The inlet part 144 widens out to the flocculation chamber 130 to decrease a flow rate of the substance flowing into the flocculation chamber. As such, a first part 146 of the inlet part 144 has a diameter similar to that of the conduit system 106, and a second part 148 of the inlet part 144 tapers out to a larger diameter similar to the diameter of the flocculation chamber 130. The outlet part 124 tapers away from the magnetic separation chamber 110 to a diameter similar to that of the conduit system 106. In this embodiment the inlet part 144 and the outlet part 124 are arranged on different sides (such as opposite) of the magnetic separation chamber.

[0079] The first holders 118 of the magnetic separation chamber 110 extend into the first space 114, such that a longitudinal direction of the first holders 118 is substantially perpendicular to a downstream direction Du directed from the flocculation chamber 130 towards the magnetic separation chamber 110. Each first holder 118 comprises a tube that is closed at one end that is located in the first space 114. The first magnets 116 have a rod-like shape. Each rod-like first magnet 116 extends into one first holder 118 with a releasable fit, i.e. an air gap between an internal wall of the first holder and the first magnet 116. As the first magnets extend into the first space, a direction of the first magnetic fields is substantially perpendicular to the downstream direction Du.

[0080] The second holders 140 of the flocculation chamber 130 extend into the second space 136, such that a longitudinal direction of the second holders 140 is substantially perpendicular to a downstream direction Du directed from the flocculation chamber 130 towards the magnetic separation chamber 110. Each second holder 140 comprises a tube that is closed at one end that is located in the first space 136. The tube may even extend from a first side of the flocculation chamber 130 to beyond a second opposite side of the flocculation chamber 130, as shown in FIG. 2. The second magnets 138 have a rod-like shape. Each rod-like second magnet 138 extends into one second holder 140 with a releasable fit, i.e. an air gap between an internal wall of the second holder 140 and the second magnet 138. A longitudinal direction of the second holders is substantially perpendicular to the downstream direction Du from the flocculation chamber towards the magnetic separation chamber. As the second magnets 138 extend into the second space 136, a direction of the second magnetic fields is substantially perpendicular to the downstream direction Du.

[0081] The second magnets 138 have a cross section that has a greater dimension in the downstream direction Du with respect to a dimension in a direction transverse to the downstream direction, i.e. the major dimension is directed in the downstream direction. FIG. 1 shows that the cross section of the second magnets 138 is rectangular with rounded transverse edges, looking like a flattened ellipse or circle. The major dimension of the rectangular cross section is directed in the downstream direction. The cross section of the second holder 140 is similar to that of the second magnet 138, however with slightly larger dimensions to allow for an air gap between the second holder 140 and the second magnet 138.

[0082] The first magnets 116 have a circular cross section. The cross section of the first holder is similar to that of the first magnets, however with a slightly larger diameter to allow for an air gap between the first holder 118 and the first magnet 116.

[0083] The magnetic separation chamber 110 further comprises a cleaning system 126 to clean the inside of the first housing 112. The cleaning system 126 may comprise, a sprinkling or spraying member to clean the outside of each tube by spraying a fluidum towards the first holders 118. Said sprinkling or spraying member may comprise an annular pipe provided with a plurality of sprinkling or spraying nozzles which can be fed with a fluid, such as a liquid or gas. The nozzles can be situated in the first space 114 in various ways. According to FIG. 1, the nozzles are situated near the closed end of the tubes 118 in the first space 114, near the bottom of the first housing 112.

[0084] FIGS. 3a-3d show several views of a device 150 for pre-magnetizing magnetizable particles according to the invention (perspective, front view, side view, and top view, respectively). The device 150 comprises the flocculation chamber 130 for inducing flocculation of the particles in the substance. The flocculation chamber comprises the housing 134 that defines the second space 136 through which the substance can flow, as well as a plurality of second magnets 138 that extend into the second space 136, such that their magnetic fields reach into the second space 136. The magnets are located within the second holders 140 that each have an interface 142 with the second space 136.

[0085] The device 150 is connectable to the magnetic separation chamber 110 by means of connection flange 132. Further connection flange 128 can be used to connect the inlet part 144 to the flocculation chamber 130. The device 150 can be used for retrofitting an existing magnetic separation system or any other system, method, or technology for separation in need of a pre-magnetization treatment such as those involving hydro cyclone or multi cyclone technology.

[0086] FIG. 4 shows a top view of the magnetic separation system comprising the apparatus 100 of FIG. 1. The system further comprises a part of the conduit system 106 and a bypass system 108. The bypass system 108 is used at least during a cleaning process of the apparatus 100. The flow of substance through the apparatus 100 can be stopped by means of closure of a first valve 152 located before the inlet part, with respect to the flow direction of the substance. In addition, to avoid a backflow of the substance into the apparatus 100 while cleaning, a second valve 154 located downstream from the magnetic separation chamber 110 is closed as well, closing off the magnetic separation chamber 110. A third valve 156 provided at the bypass system 108, is opened to open the bypass system, such that the flow of substance bypasses the apparatus 100. FIG. 4 further shows a first movement mechanism 102 to move the first magnets 116 with respect to the first holders 118, and a second movement mechanism 104 to move the second magnets 138 with respect to the second holders 140.

[0087] FIG. 5a shows a schematic view of an active magnetic separation system according to the invention, while the substance flows through the apparatus 100 and the magnetizable particles are separated from the substance by the apparatus 100. The first and second valves 152, 154 are open to allow the flow of the substance through the apparatus. The third valve 156 of the bypass system 108 is closed. The first magnets 116 are located in the first holders 118, and extend into the first space 114 of the magnetic separation chamber 130. The second magnets 138 are located in the second holders 140, and extend into the second space 136 of the flocculation chamber 130.

[0088] FIGS. 5b-5e show the system at various stages of a cleaning process. In a first step 5b of the cleaning process the first and second valves 152, 154 are open and the third valve 156 is closed (thus fluid flows through the unit). Only the second magnets are raised so that any captured particles will be forced by the fluid flow into the magnetic separation chamber where they will be captured by the first magnetic field.

[0089] FIG. 5c shows a schematic view of a magnetic separation system according to the invention during a further step of the cleaning process. The first and second valves 152, 154 are in their closed position, stopping the flow of substance through the apparatus 100. The third valve 156 is in its open position, allowing the substance to flow through the bypass system 108.

[0090] Additionally, the second magnets 138 and the first magnets 116 have been removed from the second and first holders, respectively, by the first and second movement mechanism 102, 104, respectively. The movement mechanisms 102, 104 can be hydraulically actuated, but other forms of actuation may be used as well. For the apparatus of FIGS. 1-5, the movement mechanisms 102, 104 raise the magnets with respect to the respective holders. This direction of movement with respect of the holders of course depends on the orientation of the holders and the apparatus and may be in any horizontal and/or vertical direction applicable.

[0091] FIG. 5d shows a schematic view of the magnetic separation system according to the invention during the cleaning process. The first and second magnets 116, 138 have been raised from the respective holders 118, 140. When the magnets 116, 138 are raised out of their holder, the strengths of the magnetic fields in the first and second spaces decrease considerably, as a result of which the particles and/or flocs accumulated on the outside of the holders can easily be removed. In order to ensure that the particles or flocs do not enter the cleaned liquid again, the bottom wall of the first housing 112 is provided with a discharge 158 for removing the magnetizable parts which accumulated on the outside of each tube.

[0092] Despite the removal of the magnets, some particles may nevertheless remain behind on the holder wall. In order to be able to remove these particles reliably, the sprinkling or spraying member for cleaning the outside of each tube is situated near the bottom end of each tube. The spraying member is part of the cleaning system and sprays a fluid (liquid or gas) towards the tubes to remove any particles left on the holder wall. The sprayed-off particles are then removed from the magnetic separation chamber 110 through the discharge 158.

[0093] FIG. 5e shows a schematic view of a magnetic separation system according to the invention during finishing of the cleaning process. The first and second magnets 116, 138 are lowered again by the respective movement mechanisms 102, 104 into their respective holders 118, 140. While lowering the magnets, the first and second valves 152, 154 remain closed and the third valve 156 remains open. The discharge 158 is closed as well. Only when the magnets are fully lowered into their holders, will the first and second valves be opened and the third valve be closed again. Then the substance will flow through the apparatus 100 again and the magnetizable particles will undergo flocculation and separation, subsequently, according to FIG. 5a.

[0094] FIG. 5f shows a schematic view of a magnetic separation system according to the invention during active filtration, after the cleaning process is finished.

[0095] FIGS. 6a-6b show a cross-section A-A and a top view, respectively, of an embodiment wherein the magnetic elements are arranged in substantially parallel orientation with respect to the general direction of the substance flow (downstream direction Du), while FIG. 6c shows a top view of this embodiment connected to the conduit and bypass system. The flow in this embodiment enters the magnetic separation chamber via an inlet 144 and via the flocculation chamber 130. The substance flows downward through the magnetic separation chamber and exits via the outlet 124. FIGS. 6a-6b show the inlet part 144 and the outlet part 124 are both arranged on the same side of the magnetic separation chamber. Alternatively, the inlet part 144 and the outlet part 124 may be arranged on different (such as opposite) sides of the magnetic separation chamber. Moreover, it is noted herein that Du can alternatively flow in a different direction from the one depicted in the figure. For example, the elements can be arranged such that Du flows in a direction opposite as the depicted direction. In that case the function of the shown elements 124 and 144 would be respectively inverted, with the shown outlet 124 assuming an inlet function, and the shown inlet 144 assuming an outlet function.

[0096] FIGS. 7a-7b show a cross-section A-A and a top view, respectively, of an embodiment of the magnetic separation system according to the invention wherein the magnets are arranged in perpendicular orientation to the general direction of the substance flow. FIG. 7c shows a view of the magnetic separation system with a bypass element 108. A draining outlet 158 is shown in FIG. 7a, which functions to drain residue during the cleaning process.

[0097] While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

LIST OF PARTS

[0098] 100. Apparatus/system [0099] 102. First moving mechanism [0100] 104. Second moving mechanism [0101] 106. Conduit system [0102] 108. Bypass system [0103] 110. Magnetic separation chamber [0104] 112. First housing [0105] 114. First space [0106] 116. First magnet [0107] 118. First holder [0108] 120. First interface [0109] 122. Connection flange [0110] 124. Outlet part [0111] 126. Cleaning system [0112] 128. Further connection flange [0113] 130. Flocculation chamber [0114] 132. Connection flange [0115] 134. Second housing [0116] 136. Second space [0117] 138. Second magnet [0118] 140. Second holder [0119] 142. Second interface [0120] 144. Inlet part [0121] 146. First part of inlet [0122] 148. Second part of inlet [0123] 150. Pre-magnetizing device [0124] 152. First valve [0125] 154. Second valve [0126] 156. Third valve [0127] 158. Draining outlet