JP2020044484A - Magnetic separator, liquid processing system and liquid processing method - Google Patents

Abstract

To provide a magnetic separator capable of efficiently separating and recovering a magnetic separation object by immersing a drum in a processing liquid vessel by a half or more.SOLUTION: A magnetic separator 1000 comprises: a columnar drum 10; a first and a second bearings 20 rotatably supporting the drum around a rotation center axis extending in a first direction; a magnetic flux generation device 30 supporting a plurality of permanent magnets facing the inner peripheral surface of the drum in the inner space of the drum; and a processing liquid vessel 40 having a first side wall 40a and a second side wall 40b being orthogonally crossed, an opening 40c receiving the outer peripheral surface of the drum, a first sealing device 50a disposed at the outside of the first side wall of the processing liquid vessel and a second sealing device 50b disposed at the outside of the second side wall of the processing liquid vessel. Each of the first sealing device and the second sealing device has a slide sealing member 60 being in contact with a part projected toward outside from the processing liquid vessel in the outer peripheral surface of the drum over the distance of a half length or more in a circumferential direction.SELECTED DRAWING: Figure 1A

Description

  The present disclosure relates to a magnetic separation device, and more specifically, to a magnetic separation device that attracts a magnetic substance existing in a liquid with a magnet and separates the magnetic substance from the liquid. The present disclosure also relates to a liquid processing system including the magnetic separation device and a liquid processing method using the magnetic separation device.

  In order to treat sewage or organic wastewater, the activated sludge method has been widely used. In the activated sludge method, activated sludge is mixed with treated water such as sewage and aerated. Activated sludge is a floating organic sludge containing aerobic microorganisms cultivated and grown artificially and engineeringly. Aerobic microorganisms are active in the aerated sludge. Aerobic microorganisms decompose organic matter contained in the treated water to propagate and form aggregates (flocs). Such flocs separate from clean water by natural settling. However, the activated sludge method has a problem that the time required for separation is long because the separation of flocs depends on natural sedimentation.

  A magnetized activated sludge method in which a magnetic separation technique is applied to an activated sludge method has been proposed. In the magnetized activated sludge method, powder particles of a ferromagnetic material such as ferric oxide or ferrite are added to an activated sludge suspension. Sludge flocs capture ferromagnetic powder particles to form magnetic flocs. In the magnetized activated sludge method, magnetic flocs are collected by magnetic force and magnetically separated. Since the magnetized activated sludge method performs magnetic separation without relying on time-consuming settling separation, it is possible to solve the problem that the conventional activated sludge method has a long processing time. For magnetic separation, a magnetic separation device provided with a magnetic drum or a magnetic disk is used.

  Patent Documents 1 to 4 disclose conventional treatment methods and apparatuses using a magnetized activated sludge method.

JP-B-63-59759 WO 2004/054935 JP 2005-161160 A JP 2005-161161 A

  In each of the devices disclosed in Patent Documents 1 to 4, a rotating drum having a magnet disposed on an outer peripheral surface is used. Each of these rotary drums is immersed in only about 30% of the processing liquid. One of the reasons is that when the rotating shaft (shaft) of the rotating drum is immersed in the processing liquid, the ferromagnetic powder particles contained in the processing liquid deteriorate or damage the bearing of the rotating shaft.

  If the ferromagnetic powder particles used in the magnetized activated sludge method are too heavy, they are easily separated from the flocs by gravity. For this reason, fine particles having a diameter of about 0.05 to 2 μm are used as the ferromagnetic powder fine particles. Since the flocs bonded to such fine particles are hardly adsorbed to the rotating drum, it is required to further improve the collection efficiency.

  An embodiment of the present disclosure provides a novel magnetic separation device, a liquid processing system, and a liquid processing method that can solve the above-described problems and increase the efficiency of separation and recovery.

  In a non-limiting exemplary embodiment, the magnetic separation device of the present disclosure includes a cylindrical drum having an inner peripheral surface, an outer peripheral surface, a first end surface and a second end surface, and a rotation center axis extending in a first direction. First and second bearings around which the drum is rotatably supported, a magnetic flux generator supporting a plurality of permanent magnets facing the inner peripheral surface of the drum in an inner space of the drum, and the first direction A processing liquid tank having a first side wall and a second side wall orthogonal to the processing liquid tank, the processing liquid tank having an opening for receiving the outer peripheral surface of the drum, and an outside of the first side wall of the processing liquid tank. And a second sealing device provided outside the second side wall of the processing liquid tank. Each of the first and second seal devices includes a sliding seal member that is in contact with a portion of the outer peripheral surface of the drum that protrudes outward from the processing liquid tank over a half or more circumference in a circumferential direction. Have.

  In one embodiment, the processing liquid tank has an internal space capable of storing the processing liquid such that the liquid level of the supplied processing liquid is higher than the rotation center axis of the drum.

  In one embodiment, the opening is a circular opening or a U-shaped notch.

  In one embodiment, the sliding seal member is formed of resin or rubber, and has an opening for accommodating the outer peripheral surface of the drum.

  In one embodiment, the opening of the sliding seal member is separated from a lower semicircular portion that contacts the outer peripheral surface of the drum during operation of the magnetic separator, and at least a part of the lower semicircular portion is separated from the outer peripheral surface of the drum. And an upper portion.

  In one embodiment, the plurality of permanent magnets are arranged in a range from 60% to 80% of the entire circumference along a circumferential direction around the rotation center axis.

  In one embodiment, a first bearing bracket that covers the first end face of the drum and is fixed to the first side wall of the processing liquid tank, and covers the second end face of the drum, and the processing liquid tank A second bearing bracket fixed to the second side wall of the processing liquid tank, wherein each of the first and second bearing brackets is provided with a gap between an outer peripheral surface of the drum and the sliding seal member. It has a drain hole for passing the liquid flowing out of the tank.

  In one embodiment, a scraper is provided for scraping off the substance attached to the drum.

  In one embodiment, a motor for rotating the drum is provided.

  The liquid processing system of the present disclosure may include, in a non-limiting exemplary embodiment, any one of the above magnetic separation apparatuses, an apparatus for supplying a processing liquid containing activated sludge containing magnetic powder to the processing liquid tank, A device for collecting the activated sludge containing magnetic powder separated from the treatment liquid in the liquid tank by the magnetic separation device.

  The liquid treatment method of the present disclosure, in a non-limiting exemplary embodiment, is a liquid treatment method performed using the at least one magnetic separation device described above, wherein the treatment liquid containing the activated sludge containing magnetic powder is The method includes a step of supplying the activated sludge separated by the magnetic separation device from the treatment liquid in the treatment liquid tank to the activated sludge separated from the treatment liquid in the treatment liquid tank.

  In one embodiment, in the step of supplying the processing liquid to the processing liquid tank, the processing liquid is supplied to the processing liquid tank such that a liquid level of the processing liquid is higher than a rotation center axis of the drum. Then, in the step of recovering the activated sludge containing the magnetic powder, the drum is rotated while at least half of the outer peripheral surface of the drum is immersed in the treatment liquid.

  According to the embodiment of the present disclosure, since the cylindrical drum can be immersed in the processing liquid tank by half or more, the area of the region where the processing liquid contacts the outer peripheral surface of the drum can be increased. As a result, it is possible to efficiently separate or collect a magnetic separation target such as a magnetic floe.

It is a figure showing typically the plane composition of magnetic separation device 1000 in this embodiment. FIG. 1B is a sectional view taken along line B1-B1 of the magnetic separation device 1000 in FIG. 1A. FIG. 4 is a diagram schematically illustrating a drum around a first side wall of a processing liquid tank. FIG. 3 is a side view of the configuration shown in FIG. 2. It is a figure showing the example of composition of the 1st seal device 50a. FIG. 4B is a sectional view taken along line B4-B4 of the drum 10 in FIG. 4A. FIG. 4B is a sectional view taken along line C4-C4 of the sliding seal member 60 in FIG. 4A. It is a figure showing the example of composition of the 1st seal device 50a. FIG. 5B is a cross-sectional view of the first sealing device 50a along line B5-B5 in FIG. 5A. FIG. 5B is a cross-sectional view of the first sealing device 50a along line C5-C5 in FIG. 5A. It is a figure which expands and shows the sliding seal member 60. It is sectional drawing which shows the structure of the 1st sealing apparatus 50a. FIG. 2 is a cross-sectional view illustrating a configuration example of a magnetic flux generator 30 placed inside a drum 10. It is sectional drawing which shows the structural example of the drum 10 and the magnetic flux generator 30 put in a different state. FIG. 1 is a diagram illustrating a configuration example of a liquid processing system according to the present disclosure.

  A basic configuration example of the magnetic separation device according to the present embodiment will be described with reference to FIGS. 1A and 1B. FIG. 1A is a diagram schematically illustrating a planar configuration of a magnetic separation device 1000 according to the present embodiment. FIG. 1B is a cross-sectional view of the magnetic separator 1000 taken along line B1-B1 in FIG. 1A. In the accompanying drawings, mutually orthogonal X, Y, and Z axes are shown for reference. The Z axis is parallel to the vertical direction.

  The illustrated magnetic separation device 1000 includes a cylindrical drum 10 extending in the X-axis direction (first direction) and a first drum 10 rotatably supporting the drum 10 around a rotation center axis C parallel to the X-axis. And a second bearing 20, a magnetic flux generator 30, and a processing liquid tank 40.

  The drum 10 is a cylindrical body (having a thickness of about several mm) formed of a non-magnetic material such as SUS304, and has an inner peripheral surface 10a, an outer peripheral surface 10b, a first end surface 10c, and a second end surface 10d. I have. The outer diameter of the drum 10 (the diameter of the outer peripheral surface 10b) is, for example, 2 to 100 cm, preferably 10 to 60 cm. The length of the drum 10 (the distance from the first end face 10c to the second end face 10d) is, for example, 5 to 500 cm, preferably 50 to 300 cm. The magnetic flux generator 30 supports a plurality of permanent magnets facing the inner peripheral surface 10a of the drum 10 in the internal space 10s of the drum 10. The permanent magnet is fixed and does not change position while the drum 10 is rotating. The permanent magnets are arranged in a range of 60% to 80% of the entire circumference along a circumferential direction around the rotation center axis C, and constitute a plurality of magnetic pole pairs (N pole and S pole). . The magnetic flux formed by the magnetic pole pair is also distributed outside the outer peripheral surface 10b through the non-magnetic drum 10, and attracts the magnetic substance in the processing liquid to the outer peripheral surface 10b of the drum 10.

  The processing liquid tank 40 has a first side wall 40 a and a second side wall 40 b orthogonal to the X axis, and has an opening 40 c for receiving the outer peripheral surface 10 b of the drum 10. The processing liquid tank 40 is also formed from a non-magnetic material such as SUS304. As shown in FIG. 1B, the processing liquid tank 40 has an internal space that can store the processing liquid 90 such that the liquid level of the supplied processing liquid 90 is higher than the rotation center axis C of the drum 10. ing. The depth of the processing liquid tank 40 may be, for example, about 10 to 60 cm. In the example of FIG. 1B, the bottom surface of the processing liquid tank 40 is flat, but the shape of the processing liquid tank 40 is not limited to this example.

  Here, FIG. 2 and FIG. 3 are referred to. FIG. 2 is a diagram schematically illustrating a part of the drum 10 around the first side wall 40 a of the processing liquid tank 40. FIG. 3 is a side view of the configuration shown in FIG. For simplicity, parts such as the bearing 20 are not shown. The center of the shaft 10X of the drum 10 coincides with the rotation center axis C. As is clear from FIG. 3, the opening 40c in this example is a U-shaped notch. If the opening 40c is a U-shaped notch, the drum 10 can be easily installed from above. The drum 10 protrudes outward from the first side wall 40a and the second side wall 40b of the processing liquid tank 40 through the opening 40c (see FIG. 1A). The shape of the opening 40c is not limited to the U-shaped notch, but may be another shape such as a circle.

  In FIG. 3, reference numeral H1 indicates a height of the rotation center axis C of the drum 10 from a reference surface, and reference numeral H2 indicates a reference surface (for example, a bottom surface) of the processing liquid supplied to the processing liquid tank 40 during operation. 2 shows an example of the liquid level from the top. In operation, at least a portion of the upper half, as well as the lower half of the drum 10, will be immersed in the processing liquid (see FIG. 1B).

  Referring back to FIG. 1A. The magnetic separation device 1000 includes a first sealing device 50a provided outside the first side wall 40a of the processing liquid tank 40 and a second sealing device 50b provided outside the second side wall 40b of the processing liquid tank 40. Have. Each of the first sealing device 50a and the second sealing device 50b contacts a portion of the outer peripheral surface 10b of the drum 10 that protrudes outward from the processing liquid tank 40 over a distance of at least half a circumference in the circumferential direction. It has a dynamic seal member 60. The sliding seal member 60 is formed of, for example, resin or rubber. The details of the sliding seal member 60 will be described later.

  The magnetic separation device 1000 includes a first bearing bracket 70a that covers the first end face 10c of the drum 10, and a second bearing bracket 70b that covers the second end face 10d of the drum 10. The position of the first bearing bracket 70a is fixed to the first side wall 40a of the processing liquid tank 40. The position of the second bearing bracket 70b is fixed to the second side wall 40b of the processing liquid tank 40. As will be described later, each of the first bearing bracket 70a and the second bearing bracket 70b has a drain hole through which a liquid flowing out of the processing liquid tank 40 passes through a gap between the outer peripheral surface 10b of the drum 10 and the sliding seal member 60. 70c (FIG. 7). The first bearing bracket 70a and the second bearing bracket 70b are also formed from a non-magnetic material such as SUS304.

  The magnetic separation device 1000 includes a scraper 100 (FIG. 1B) that scrapes off substances attached to the drum 10 and a motor (not shown) that rotates the drum 10.

  Next, a configuration example of the first seal device 50a in the present embodiment will be described with reference to FIGS. 4A to 4C and FIGS. 5A to 5C. The second sealing device 50b has a configuration similar to that of the first sealing device 50a.

  4A and 5A are diagrams illustrating a configuration example of the first sealing device 50a. 4B is a sectional view taken along line B4-B4 of the drum 10 in FIG. 4A, and FIG. 4C is a sectional view taken along line C4-C4 of the sliding seal member 60 in FIG. 4A. In FIG. 4C, the outline of the first side wall 40a is indicated by a broken line for reference. FIG. 5B is a cross-sectional view taken along line B5-B5 of the first seal device 50a in FIG. 5A, and FIG. 5C is a cross-sectional view taken along line C5-C5 of the first seal device 50a in FIG. 5A.

  As shown in FIGS. 4A and 5A, the first sealing device 50a in the present embodiment has ring-shaped pressing plates 80a and 80b that sandwich the sliding seal member 60. The holding plate 80a is fixed to the processing liquid tank 40, and sandwiches the sliding seal member 60 with the other holding plate 80b.

  As shown in FIG. 4C, the sliding seal member 60 in the present embodiment has a plurality of small holes for fixing the position. The sliding seal member 60 can be suitably formed of a soft non-magnetic material such as rubber (nitrile rubber, chloroprene rubber, or the like) having a Shore S hardness of about 50 to 70, or a resin (plastic). When the friction between the sliding seal member 60 and the rotating drum 10 causes abrasion of the sliding seal member 60, the gap between the sliding seal member 60 and the outer peripheral surface 10b of the drum 10 is insufficiently sealed. Become. In such a case, a new sliding seal member may be replaced as a consumable. If the sliding seal member 60 is formed from a material having a hardness higher than the above-described hardness, the wear is likely to progress, and the frequency of replacement may increase.

  FIGS. 5B and 5C schematically show examples of the shapes of the holding plates 80a and 80b, respectively. The holding plates 80a and 80b have a plurality of through holes that match the plurality of holes of the sliding seal member 60 shown in FIG. 4C. The sliding seal member 60 can be pressed and fixed from both sides by adjusting the interval between the holding plates 80a and 80b with bolts or the like passing through these through holes. The sliding seal member 60 is stretched in the radial direction by being clamped in the thickness direction by the pressing plates 80a and 80b. As a result, the frictional force at the portion where the sliding seal member 60 contacts the outer peripheral surface 10b of the drum 10 can increase. Therefore, by adjusting the interval between the pressing plates 80a and 80b, the sliding resistance exerted on the outer peripheral surface 10b of the drum 10 by the sliding seal member 60 can be controlled. When the sliding seal member 60 is fixed with a bolt or the like, the sliding seal member 60 is evenly and gradually tightened along the circumferential direction of the sliding seal member 60 so that the sliding seal member 60 exerts a sliding effect on the outer peripheral surface 10 b of the drum 10. It is preferable to make the resistance as uniform as possible in the circumferential direction. The pressing plate 80a does not need to be a separate component that can be separated from the processing liquid tank 40, and may be a part of the first side wall 40a (second side wall 40b) of the processing liquid tank 40. As described later, the holding plate 80a may have a U-shaped shape. For example, the periphery of the notch of the first side wall 40a (the second side wall 40b) may be used as a U-shaped pressing plate 80a. In this case, for example, the upper part of the U-shaped pressing plate 80a may be reinforced with another arc-shaped part, and fixed to the circular sliding seal member 60 and the pressing plate 80b. Further, the structure for fixing the sliding seal member 60 is not limited to the example in the present embodiment, and various structures can be adopted.

  FIG. 6 is an enlarged view showing the sliding seal member 60. In FIG. 6, the position of the outer peripheral surface 10b of the drum 10 is indicated by a broken line for reference. As shown in FIG. 6, the sliding seal member 60 has an opening 60p for accommodating the outer peripheral surface 10b of the drum 10, and the opening 60p is It includes a lower semicircular portion that contacts the outer peripheral surface 10b of the drum 10 and an upper portion that is at least partially separated from the outer peripheral surface 10b of the drum 10. The opening 60p of the sliding seal member 60 in the example of FIG. 6 is generally circular, but the upper part and the lower part are vertically asymmetric. Specifically, the radius of the upper portion of the opening 60p is longer than the outer diameter of the drum 10, and a gap G exists between the outer peripheral surface 10b of the drum 10 and the sliding seal member 60. Since such a gap G is located at a position higher than the liquid level of the processing liquid, it is not necessary to seal the gap. Rather, the presence of the gap G having a size larger than zero (for example, 0.1 to 5 mm) at the upper part of the drum 10 provides an effect of reducing sliding friction.

  The role required of the sliding seal member 60 is to seal the processing liquid in a region of the outer peripheral surface 10b of the drum 10 that is in contact with the processing liquid. Therefore, the sliding seal member 60 may be cut off in a region of the outer peripheral surface 10b of the drum 10 that does not contact the processing liquid at all. Therefore, the sliding seal member 60 may have a U-shaped shape with its upper part cut off. In that case, the holding plates 80a and 80b may also have a U-shaped shape.

  The gap G needs to have a substantially zero size at a portion where the outer peripheral surface 10b of the drum 10 is immersed in the processing liquid. In the example of FIG. 6, there is a portion where the size of the gap G is not zero in the lower half of the sliding seal member 60, but when the magnetic separator 1000 is operated, the pressing plates 80 a and 80 b are set to be substantially zero. Is adjusted. When the drum 10 is rotating, a part of the sliding seal member 60 that receives sliding friction is elastically deformed, so that an extremely small gap is not formed between the sliding seal member 60 and the outer peripheral surface 10b of the drum 10. It can occur uniformly and intermittently. The formation of such a small gap may cause the processing liquid to leak from the processing liquid tank 40. In order to prevent such a small gap from being formed at all, the radius of the lower portion of the opening 60p of the sliding seal member 60 is reduced, and the pressing force of the sliding seal member 60 against the outer peripheral surface 10b of the drum 10 is reduced. Need to be strengthened. If the pressing force is increased in such a manner, the resistance to sliding friction becomes too large, so that it may be necessary to increase the driving force of the motor, or the deterioration of the sliding seal member 60 may be accelerated. On the other hand, in the present embodiment, the sealing performance of the sliding seal member 60 is intentionally suppressed to be low, and the processing liquid is processed through the small gap generated between the sliding seal member 60 and the outer peripheral surface 10b of the drum 10. Leakage from the liquid tank 40 is allowed. The presence of the processing liquid in the small gap between the sliding seal member 60 and the outer peripheral surface 10b of the drum 10 contributes to smooth rotation of the drum 10 to reduce sliding resistance.

  Next, a configuration example of the first bearing bracket 70a that covers the first end face 10c of the drum 10 will be described with reference to FIG. The configuration of the second bearing bracket 70b that covers the second end face 10d of the drum 10 is the same as the configuration of the first bearing bracket 70a.

  The first bearing bracket 70a illustrated in FIG. 7 includes the first bearing 20, and is fixed to the processing liquid tank 40 so as to form a space 70s between the first bearing bracket 20 and the first end face 10c of the drum 10. Here, that the first bearing bracket 70a is fixed to the processing liquid tank 40 means that the position of the first bearing bracket 70a is fixed with respect to the processing liquid tank 40, that is, the first bearing bracket 70a is It is directly or indirectly fixed to the liquid tank 40. In the example of FIG. 7, the first bearing bracket 70a is indirectly fixed to the processing liquid tank 40 by being fixed to the holding plate 80b by welding or the like. The processing liquid leaking from the processing liquid tank 40 enters the space 70s formed by the first bearing bracket 70a. Since the drainage hole 70c is provided at the lowermost part of the first bearing bracket 70a, the processing liquid is discharged outside through the drainage hole 70c. The drain hole 70c has, for example, a shape of a hose joint, and can be connected to a hose (not shown). The processing liquid that has leaked into the space 70s of the first bearing bracket 70a can be collected through the drain hole 70c.

  A configuration example of the magnetic flux generator 30 will be described with reference to FIGS. 8A and 8B. FIG. 8A is a cross-sectional view showing a configuration example of the drum 10 and the magnetic flux generator 30 placed inside. FIG. 8B is a cross-sectional view illustrating a configuration example of the drum 10 and the magnetic flux generator 30 in a separated state in order to clearly show each configuration.

  In the internal space 10s of the drum 10 shown in FIG. 8B, the magnetic flux generator 30 shown in FIG. 8B is fixed coaxially. The magnetic flux generator 30 includes an inner cylinder 34 in which a plurality of permanent magnets 32 are arranged on an outer peripheral surface. Although the drum 10 rotates while being supported by the first and second bearings 20 (see FIG. 1A), the inner cylinder 34 is fixed by means not shown (the fixing means is optional) and does not rotate. Therefore, the magnetic flux formed by the permanent magnet 32 has a spatially fixed intensity distribution. The plurality of permanent magnets 32 are arranged so that a magnetic flux having a desired strength acts on the outer peripheral surface 10b of the drum 10. The arrangement of the permanent magnets 32 is appropriately set according to the outer diameter of the drum 10, the position of the scraper 100, and the like.

  As shown in FIG. 8B, the plurality of permanent magnets 32 pass from a position Ps at a height close to the height of the rotation center axis C to a position facing the lower region of the inner peripheral surface 10 a of the drum 10, The scraper 100 is disposed up to the vicinity of the position Pe facing the portion in contact with the drum 10. Specifically, the plurality of permanent magnets 32 are arranged in a range from 60% to 80% of the entire circumference along the circumferential direction around the rotation center axis.

  A preferred example of the permanent magnet 32 is an Nd-Fe-B-based rare earth magnet. The permanent magnet disposed near the tip of the scraper 100 may be a magnet having a relatively small magnetic force, such as a ferrite magnet. With such a permanent magnet arrangement, the magnetic flocs in the processing liquid can be efficiently adsorbed to the outer peripheral surface 10b of the drum 10, and the adsorbed magnetic flocs can be easily scraped off by the scraper 100.

  A part of the bottom of the processing liquid tank 40 may have a concave portion facing the outer peripheral surface 10 b of the drum 10 and conforming to the shape of the drum 10. By providing such a concave portion, a flow path of the processing liquid is formed between the outer peripheral surface 10b of the drum 10 and the concave portion, and the magnetic flocs can be more efficiently captured.

  The magnetic floc existing in the processing liquid tank 40 can be formed by adding magnetic powder to activated sludge and adsorbing and holding it in another processing liquid tank (aeration tank) (not shown). The magnetic flocks of the processing liquid tank 40 may include the remaining magnetic flocks after the processing by another magnetic separation device 1000 is performed.

Desirably, the magnetic powder can be composed of powder particles having a particle size of 0.05 to 2 μm. When the particle size is larger than 2 μm, individual magnetic powder particles are easily separated from the activated sludge. If the particle size is smaller than 0.05 μm, the production cost increases. A more preferred range for the particle size is 0.1 to 1.0 μm. The preferable range of the coercive force of the magnetic powder particles is 0 to 16 kA / m. If the coercive force is larger than this range, the magnetic powder particles aggregate. The smaller the coercive force, the more easily the magnetic flocks can be separated from the drum 10, which is preferable. The magnetic powder particles may be formed from either ferromagnetic or paramagnetic materials. Examples of suitable materials include iron oxide, cobalt, chromium oxide, ferrite, and the like. Considering the production cost and the like, a powder of triiron tetroxide (magnetite, Fe ₃ O ₄ ) having a particle size of 0.1 to 1.0 μm is preferable.

  Hereinafter, an embodiment of a liquid processing system and a liquid processing method according to the present disclosure will be described with reference to FIG. FIG. 9 is a diagram illustrating a configuration example of a liquid processing system according to the present embodiment.

  First, a magnetic floc (active sludge containing magnetic powder) and sewage are mixed in an aeration tank (not shown). Microorganisms in the magnetic floc take in organic matter in the wastewater and decompose to form a treatment liquid 90 in which the magnetic floc and fresh water are mixed. The processing liquid 90 is sent to the processing liquid tank 40 of the magnetic separation device 1000 by the supply device 200.

  More than half of the drum 10 of the magnetic separation device 1000 in the vertical direction is immersed in the processing liquid 90 in the processing liquid tank 40. The gap between the processing liquid tank 40 and the drum 10 is sealed by the sliding seal member 60 described above. Therefore, when the drum 10 is not rotating, the processing liquid does not leak out of the processing liquid tank 40 to the outside. However, since the sliding seal member 60 is formed of a soft material, when the drum 10 is rotated as described above, the processing liquid flows into the space 70s of the bracket 70a (70b) in FIG. Leaks out. However, the processing liquid that has entered the space 70s is discharged to the outside through the drain hole 70c before reaching the bearing 20. Thus, the drum 10 can be deeply immersed in the processing liquid without causing the problem that the bearing 20 of FIG. 7 sandwiches the magnetic powder particles in the processing liquid. As a result, the magnetic floc can be adsorbed by utilizing a wide range (for example, 60% or more) of the outer peripheral surface of the drum 10 and can be efficiently recovered from the processing liquid.

  In the example shown in FIG. 9, the magnetic flocs in the processing liquid 90 are adsorbed on the outer peripheral surface of the rotating drum 10, scraped off by the scraper 100, and collected by the collecting unit 120. The magnetic powder particles and microorganisms in the magnetic flocks are recycled and circulated. The fresh water flows beyond the flow path 220 without being adsorbed on the drum 10.

  The plurality of magnetic separation devices 1000 may be connected in multiple stages in series or in parallel. In the example of FIG. 9, two-stage magnetic separation devices 1000 are connected in series. When a plurality of magnetic separation devices 1000 are connected in series, fresh water separated from most of the magnetic flocks by the N-th (N is an integer of 1 or more) magnetic separation device is separated into N + 1-th magnetic separation devices. It can be charged into the processing liquid tank 40 of the apparatus 1000 to further continue magnetic separation. By performing the magnetic separation in such multiple stages, the cleanliness of fresh water can be improved, and the magnetic flocs can be reliably collected and circulated without waste.

  The use of the magnetic separation device of the present disclosure is not limited to the use of separating the activated sludge containing magnetic powder from the treatment liquid containing the activated sludge containing magnetic powder. When a magnetic substance that can be attracted to a drum by a magnetic force is present in a liquid, the magnetic separation device of the present disclosure can be widely used for separating the magnetic substance from the liquid.

  The embodiment of the present invention can be widely used for a technique for separating at least a part of the activated sludge containing the magnetic powder contained in the activated sludge suspension by a magnet. It can also be used as a coolant separator that separates and collects chips, such as steel, castings and magnets, generated by cutting from the coolant.

  DESCRIPTION OF SYMBOLS 10 ... drum, 10a ... inner peripheral surface, 10b ... outer peripheral surface, 10c ... 1st end surface, 10d ... 2nd end surface, 10s ... internal space, 20 ... bearing, Reference numeral 30: magnetic flux generator, 40: treatment liquid tank, 40a: first side wall, 40b: second side wall, 40c: opening, 50a: first seal device, 50b ..Second sealing device, 60 sliding seal member, 600 scraper, 1000 magnetic separation device

Claims (12)

A cylindrical drum having an inner peripheral surface, an outer peripheral surface, a first end surface and a second end surface;
First and second bearings rotatably supporting the drum about a rotation center axis extending in a first direction;
A magnetic flux generator that supports a plurality of permanent magnets facing the inner peripheral surface of the drum in the internal space of the drum,
A processing liquid tank having a first side wall and a second side wall orthogonal to the first direction, the processing liquid tank having an opening for receiving an outer peripheral surface of the drum;
A first sealing device provided outside the first side wall of the processing liquid tank;
A second sealing device provided outside the second side wall of the processing liquid tank;
With
Each of the first and second sealing devices includes:
A magnetic separation device, comprising: a sliding seal member that contacts a portion of the outer peripheral surface of the drum that protrudes outward from the processing liquid tank over a half or more circumference in a circumferential direction.   2. The magnetic device according to claim 1, wherein the processing liquid tank has an internal space capable of storing the processing liquid such that a liquid level of the supplied processing liquid is higher than a rotation center axis of the drum. 3. Separation device.   The magnetic separator according to claim 1, wherein the opening is a circular opening or a U-shaped notch.   4. The magnetic separation device according to claim 1, wherein the sliding seal member is formed of resin or rubber, and has an opening that accommodates an outer peripheral surface of the drum. 5.   The opening of the sliding seal member has a lower semicircular portion that contacts the outer peripheral surface of the drum during operation of the magnetic separation device, and an upper portion that is at least partially separated from the outer peripheral surface of the drum. The magnetic separation device according to claim 4, comprising:   The magnetic separation according to any one of claims 1 to 5, wherein the plurality of permanent magnets are arranged in a range from 60% to 80% of the entire circumference along a circumferential direction around the rotation center axis. apparatus. A first bearing bracket covering the first end surface of the drum and fixed to the first side wall of the processing liquid tank;
A second bearing bracket covering the second end surface of the drum and fixed to the second side wall of the processing liquid tank;
With
2. The first and second bearing brackets each have a drain hole through which a liquid flowing out of the processing liquid tank passes through a gap between an outer peripheral surface of the drum and the sliding seal member. 3. 7. The magnetic separation device according to any one of items 1 to 6.   The magnetic separation device according to any one of claims 1 to 7, further comprising a scraper for scraping off a substance attached to the drum.   The magnetic separation device according to any one of claims 1 to 8, further comprising a motor that rotates the drum. A magnetic separation device according to any one of claims 1 to 9,
An apparatus for supplying a processing liquid containing magnetic powder-containing activated sludge to the processing liquid tank,
An apparatus for collecting the magnetic powder-containing activated sludge separated by the magnetic separation device from the processing liquid in the processing liquid tank,
A liquid processing system comprising: A liquid treatment method performed using at least one magnetic separation device according to any one of claims 1 to 9,
Supplying a treatment liquid containing magnetic powder-containing activated sludge to the treatment liquid tank;
Recovering the activated sludge containing the magnetic powder separated by the magnetic separation device from the treatment liquid in the treatment liquid tank,
And a liquid treatment method. In the step of supplying the processing liquid to the processing liquid tank, the processing liquid is supplied to the processing liquid tank such that the liquid level of the processing liquid is higher than the rotation center axis of the drum,
The liquid treatment method according to claim 11, wherein in the step of collecting the activated sludge containing the magnetic powder, the drum is rotated in a state where at least half of the outer peripheral surface of the drum is immersed in the treatment liquid.

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