Separation device

Abstract

To provide a separation apparatus which can separate non-magnetic abrasive grain and oil from liquid to be processed such as coolant.SOLUTION: A part of a rotating mechanism outer periphery surface is immersed in liquid to be processed flowing a first channel. The outer periphery surface rotates crossing the liquid surface. Oil floating on the liquid surface is absorbed by the outer periphery surface and separated from the liquid to be processed of the first channel. The oil absorbed by the outer periphery surface of the rotating mechanism is removed from the outer periphery surface by a first scraper. An abrasive grain accumulation part is arranged in the first channel at the downstream side compared with the position where the outer periphery surface of the rotating mechanism is immersed. A non-magnetic abrasive grain having a greater specific gravity than the liquid to be processed is accumulated in the abrasive grain accumulation part. A discharge structure for liquid to be processed is arranged at the downstream side compared with the position where the outer periphery surface of the rotating mechanism is immersed in the first channel. The discharge structure for liquid to be processed separates the liquid to be processed from the abrasive grain in the first channel to discharge the liquid from the first channel.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a separation device for separating a liquid to be treated and foreign matter contained in the liquid to be treated.

Background Art

[0002] In the cutting of magnetic materials such as iron, a separation device is known that separates magnetic sludge and non-magnetic abrasive grains discharged together with a coolant from the coolant (see Patent Document 1). In this separation device, the magnetic sludge is adsorbed by magnetic force on the surface of a rotating drum and separated from the coolant. Further, the non-magnetic abrasive grains are recovered through an opening provided at the bottom of the coolant flow path. Also, a separation device is known that removes magnetic sludge and oil floating on the upper surface contained in the coolant (cutting fluid) to clean the coolant (see Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the separation device described in Patent Document 1, the abrasive grains that are not recovered through the opening are discharged together with the coolant. Further, in the device described in Patent Document 1, the coolant and oil cannot be separated. In the separation device described in Patent Document 2, non-magnetic abrasive grains cannot be separated from the coolant.

[0005] An object of the present invention is to provide a separation device capable of separating non-magnetic abrasive grains and oil from a liquid to be treated such as a coolant.

Means for Solving the Problems

[0006] According to one aspect of the present invention, a part of the region is immersed in the liquid to be treated flowing through the first flow path, and has an outer peripheral surface that circulates across the liquid surface A circulating mechanism, wherein the liquid to be treated flowing through the first flow path contains oil having a specific gravity smaller than that of the liquid to be treated and non-magnetic abrasive grains having a specific gravity larger than that of the liquid to be treated to adsorb the oil floating on the liquid surface and separate it from the liquid to be treated in the first flow path The a circulating mechanism, a first scraper for removing the oil adsorbed on the outer peripheral surface of the circulating mechanism from the outer peripheral surface of the circulating mechanism, provided on the downstream side of the position where the outer peripheral surface of the circulating mechanism is immersed in the first flow path, Contained in the liquid to be treated flowing through the first flow path an abrasive grain accumulation part where abrasive grains are accumulated, provided on the downstream side of the position where the outer peripheral surface of the circulating mechanism is immersed in the first flow path, and separating the liquid to be treated in the first flow path Contained in the liquid to be treated from the abrasive grains and discharging it from the first flow path, and a liquid to be treated discharge structure are provided, the abrasive grain accumulation part is constituted by a bottom surface lower than the bottom surface of the first flow path, the liquid to be treated discharge structure is provided with a separation device arranged above the abrasive grain accumulation part.

Effect of the Invention

[0007] It is possible to separate non-magnetic abrasive grains and oil contained in the liquid to be treated.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

[0009] A separation device according to an embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a diagram showing a planar arrangement of each component of the separation device according to the present embodiment. The separation device according to the present embodiment includes a front-stage separation device 50 and a rear-stage separation device 10. The rear-stage separation device 10 includes a housing 90, an inlet 12, a first flow path 11, an outlet 37, an abrasive grain accumulation portion 30, a first drum 20, and a motor 25. The front-stage separation device 50 includes a housing 91, an inlet 52, a second flow path 51, an outlet 53, a second drum 60, and a motor 65.

[0010] The processing liquid containing magnetic sludge, oil, and non-magnetic abrasive grains discharged from the grinding machine flows from the inlet 52 into the second flow path 51. In FIG. 1, the direction of the flow of the processing liquid is indicated by a white arrow. The processing liquid that has flowed through the second flow path 51 flows out from the outlet 53, passes through the connection flow path 40, and flows into the first flow path 11 from the inlet 12. The processing liquid that has flowed into the first flow path 11 flows out from the outlet 37. The outlet 53 is provided laterally with respect to the direction of the flow in the second flow path 51, and the inlet 12 is provided laterally with respect to the direction of the flow in the first flow path 11. When the processing liquid that has flowed through the second flow path 51 flows into the first flow path 11, the direction of the flow is reversed.

[0011] The first drum 20 rotates by the power transmitted from the motor 25 via a sprocket and a chain. The rotation axis 22 of the first drum 20 is horizontal and intersects the first flow path 11 in a plan view. The second drum 60 rotates by the power transmitted from the motor 65 via a sprocket and a chain. The rotation axis 62 of the second drum 60 is also horizontal and intersects the second flow path 51 in a plan view.

[0012] The magnetic sludge 83 contained in the liquid to be treated is discharged from the housing 91 in the direction of the flow in the second flow path 51 as indicated by the arrow in FIG. 1. The oil 81 contained in the liquid to be treated is discharged from the housing 90 in the direction opposite to the direction of the flow in the first flow path 11 as indicated by the arrow in FIG. 1. The magnetic sludge 83 and the oil 81 are discharged in the same direction when viewed from the rotation shafts 22 and 62 of the first drum 20 and the second drum 60 in a plan view.

[0013] The abrasive grain accumulation part 30 is located at the downstream end of the first flow path 11, and the non-magnetic abrasive grains 82 contained in the liquid to be treated are accumulated in the abrasive grain accumulation part 30. The liquid to be treated from which the magnetic sludge 83, the oil 81, and the abrasive grains 82 have been removed is discharged to the outside of the housing 90 through the discharge port 37.

[0014] FIG. 2 is a cross-sectional view taken along the dashed-dotted line 2-2 in FIG. 1, that is, a cross-sectional view of the subsequent separation device 10. The first flow path 11 is defined in the housing 90. An inlet 12 is provided near the left end of the side surface of the housing 90. The liquid to be treated 80 flowing in from the inlet 12 flows from left to right through the first flow path 11. In FIG. 2, the direction of the flow of the liquid to be treated 80 in the first flow path 11 is represented by an arrow. The liquid to be treated 80 flowing into the first flow path 11 contains the oil 81 used as sliding oil and the non-magnetic abrasive grains 82. Since the specific gravity of the oil 81 is smaller than the specific gravity of the liquid to be treated 80, the oil 81 floats on the liquid surface of the liquid to be treated 80. Since the specific gravity of the abrasive grains 82 is larger than the specific gravity of the liquid to be treated 80, the abrasive grains 82 gather below the liquid to be treated 80 in the first flow path 11.

[0015] A part of the outer peripheral surface 21 of the first drum 20 is immersed in the liquid 80 to be treated flowing through the first flow path 11 downstream of the inlet 12. The first drum 20 is supported in the housing 90 with its central axis parallel to the liquid level of the liquid 80 to be treated and perpendicular to the flow direction of the liquid 80 to be treated flowing through the first flow path 11. A motor 25 rotates the first drum 20 around the rotating shaft 22. When the first drum 20 is rotated, the outer peripheral surface 21 of the first drum 20 revolves so as to cross the liquid level of the liquid 80 to be treated. The rotation direction of the first drum 20 is set so that the circumferential speed direction of the outer peripheral surface 21 immersed in the liquid 80 to be treated is the same as the flow direction of the first flow path 11.

[0016] Oil 81 floating on the liquid surface is adsorbed to the outer peripheral surface 21 of the first drum 20 by surface tension, and sinks into the liquid 80 to be treated by the rotation of the first drum 20. Thereafter, the oil 81 crosses the liquid surface of the liquid 80 to be treated and is separated from the liquid 80 to be treated.

[0017] The oil 81 adsorbed on the outer peripheral surface 21 of the first drum 20 is scraped off by the first scraper 23 and removed from the outer peripheral surface 21. The oil 81 scraped off by the first scraper 23 is discharged through the oil discharge passage 24. The direction in which the oil is discharged in a plan view is opposite to the flow direction in the first flow passage 11.

[0018] The bottom surface of the first flow path 11 is inclined so as to gradually lower downstream from the lowest end of the first drum 20. The liquid to be treated 80 that has passed through the first flow path 11 below the first drum 20 is branched by the upper and lower separation plates 34 into a flow that flows obliquely upward along the outer circumferential surface 21 of the first drum 20 and a flow that flows obliquely downward along the bottom surface of the first flow path 11. Most of the abrasive grains 82, which have a high specific gravity, move along the flow that flows obliquely downward.

[0019] On the downstream side of the position where the outer peripheral surface 21 of the first drum 20 is immersed in the first flow path 11, a processing liquid discharge structure 35 is arranged. The processing liquid discharge structure 35 includes a container 36 and a discharge port 37. The container 36 has an upward-facing opening and is immersed in the processing liquid 80 of the first flow path 11. The upper end of the container 36 is arranged at a position slightly deeper than the liquid level, and the processing liquid 80 near the liquid level (surface layer portion) flows into the container 36 from the opening. The processing liquid 80 that has flowed into the container 36 is discharged to the outside of the housing 90 from the discharge port 37 provided on the side surface of the housing 90. Since abrasive grains 82 do not float near the liquid level of the processing liquid 80, the processing liquid 80 is separated from the abrasive grains 82 by the processing liquid discharge structure 35.

[0020] The abrasive grains 82 contained in the processing liquid 80 that are separated by the upper and lower separation plate 34 and directed obliquely downward are accumulated in an abrasive grain accumulation portion 30 provided at the downstream end of the first flow path 11. The abrasive grain accumulation portion 30 is constituted by a bottom surface lower than the bottom surface of the first flow path 11. The processing liquid 80 that has reached the downstream end of the first flow path 11 flows upward and flows into the container 36. The abrasive grains accumulated in the abrasive grain accumulation portion 30 are, for example, sucked using a vacuum pump or the like and removed from the housing 90.

[0021] FIG. 3 is a cross-sectional view taken along the one-dot chain line 3-3 in FIG. 1, that is, a cross-sectional view of the pre-stage separation device 50. A second flow path 51 through which the processing liquid 80 flows is defined in the housing 91. In FIG. 3, the direction of flow of the processing liquid 80 in the second flow path 51 is indicated by an arrow. The processing liquid 80 flows into the second flow path 51 from an inlet 52 provided at the right end of the housing 91. The processing liquid 80 flows leftward and flows out from an outlet 53 provided near the downstream end of the second flow path 51.

[0022] A second drum 60 is disposed within a housing 91. A partial region of an outer peripheral surface 61 of the second drum 60 is immersed in a liquid to be treated 80 flowing through a second flow path 51. The second drum 60 is supported within the housing 91 in a posture such that its central axis is parallel to the liquid level of the liquid to be treated 80 and orthogonal to the direction of flow of the liquid to be treated 80. The second drum 60 rotates around a rotating shaft 62 by a motor 65. Transmission of the driving force from the motor 65 to the second drum 60 is performed, for example, by a sprocket and a chain. The moving direction (circumferential speed direction) of the outer peripheral surface 61 of the second drum 60 is opposite to the direction of flow of the liquid to be treated 80.

[0023] An inner cylinder 63 is coaxially disposed within an internal space of the second drum 60 with a slight gap from an inner peripheral surface of the second drum 60. The inner cylinder 63 is fixed to the housing 91 and does not rotate, and a plurality of magnets 64 are arranged side by side in the circumferential direction on an outer peripheral surface of the inner cylinder 63. Each of the magnets 64 has magnetic poles of mutually different polarities appearing on an inner peripheral side surface and an outer peripheral side surface, and are arranged such that S poles and N poles appear alternately in the circumferential direction. Further, the magnets 64 are arranged in the circumferential direction in a region immersed in the liquid to be treated 80 and in a region from the immersed region to the top portion of the inner cylinder 63 in the circumferential speed direction of the outer peripheral surface 61 of the second drum 60. The plurality of magnets 64 generate a magnetic flux on the outer peripheral surface 61 of the second drum 60. Due to this magnetic flux, magnetic sludge 83 is adsorbed to the outer peripheral surface 61 of the second drum 60.

[0024] A part of the bottom surface of the second flow path 51 has a shape that reflects the shape of the outer peripheral surface 61 of the second drum 60 such that the radial dimension from the outer peripheral surface 61 of the second drum 60 to the bottom surface of the second flow path 51 falls within a predetermined range. When the liquid to be treated 80 flows in the vicinity of the outer peripheral surface 61 of the second drum 60, the magnetic sludge 83 is adsorbed to the outer peripheral surface 61 of the second drum 60 by the magnetic force of the magnets 64. The adsorbed magnetic sludge 83 moves with the rotation of the second drum 60 and is separated from the liquid to be treated 80.

[0025] At a position approximately 1 / 8 turn advanced in the circumferential speed direction from the top of the second drum 60, the second scraper 73 is in contact with the outer peripheral surface 61 of the second drum 60. No magnet 64 is arranged at the location on the outer peripheral surface of the second drum 60 where the second scraper 73 is in contact. The second scraper 73 scrapes the magnetic sludge 83 on the outer peripheral surface 61 of the second drum 60 from the outer peripheral surface 61. The magnetic sludge 83 scraped by the second scraper 73 is collected in the collection container 75 through the discharge path 74.

[0026] At a position from the contact location between the outer peripheral surface 61 of the second drum 60 and the liquid level of the liquid to be treated 80 to the top of the outer peripheral surface 61 in the circumferential speed direction, the roller 67 is pressed against the outer peripheral surface 61 of the second drum 60. The roller 67 rotates in a direction opposite to the rotation direction of the second drum 60 by power being transmitted from the rotation axis of the second drum 60 via a sprocket and a chain. An elastic body is arranged on the outer peripheral surface of the roller 67. When the magnetic sludge 83 adsorbed on the outer peripheral surface 61 of the second drum 60 passes between the second drum 60 and the roller 67, the liquid component adhering to the outer peripheral surface 61 of the second drum 60 is removed. Thereby, the magnetic sludge 83 with less liquid component can be separated and collected. In this way, the pre-stage separation device 50 separates the magnetic sludge 83 contained in the liquid to be treated 80 flowing through the second flow path 51 from the liquid to be treated 80 using magnetic force.

[0027] Next, the relationship between the first drum 20 and the second drum 60 will be described. The rotation axis 22 (FIG. 2) of the first drum 20 and the rotation axis 62 (FIG. 3) of the second drum 60 are parallel to each other, or the rotation axis 62 of the second drum 60 is located on the extension line of the rotation axis 22 of the first drum 20. The first drum 20 and the second drum 60 rotate in the same rotation direction.

[0028] FIG. 4 is a schematic diagram of a grinding apparatus that performs a coolant cleaning process using the separation device according to the present embodiment. The processed liquid 80 used as a coolant is discharged from the grinding wheel 100. The processed liquid 80 contains magnetic sludge 83, non-magnetic abrasive grains 82, and oil 81. The processed liquid 80 flows into the front-stage separation device 50 from the inlet 52.

[0029] The front-stage separation device 50 separates the magnetic sludge 83 from the processed liquid 80 and collects it in the collection container 75. The processed liquid 80 flows out from the outlet 53 of the front-stage separation device 50 and flows into the rear-stage separation device 10 from the inlet 12. The oil separated by the rear-stage separation device 10 is introduced into the oil-water separation tank 102. The oil-water separation tank 102 further separates the processed liquid 80 and the oil 81, and the oil 81 is collected in the collection container 103. The processed liquid 80 separated by the oil-water separation tank 102 is collected in the coolant tank 101. Further, the processed liquid 80 flowing out from the discharge port 37 of the rear-stage separation device 10 is collected in the coolant tank 101. The processed liquid 80 collected in the coolant tank 101 is supplied to the grinding wheel 100 by the pump 104.

[0030] The non-magnetic abrasive grains 82 contained in the processed liquid 80 are accumulated in the abrasive grain accumulation portion 30 of the rear-stage separation device 10.

[0031] Next, the excellent effects of the above embodiment will be described. With the separation device according to the above embodiment, the magnetic sludge 83, the oil 81, and the abrasive grains 82 can be separated from the processed liquid 80. Also, the flow direction of the processed liquid 80 in the second flow path 51 and the flow direction of the processed liquid 80 in the first flow path 11 are opposite to each other in plan view. That is, the flow of the processed liquid 80 is turned back during the process. For this reason, it is possible to shorten the overall length of the device. By installing the front-stage separation device 50 and the rear-stage separation device 10 above the coolant tank 101 (FIG. 4), space can be saved.

[0032] As shown in FIG. 1, in a plan view, the magnetic sludge 83 and the oil 81 are discharged in the same direction when viewed from the rotation axis 22 of the first drum 20 and the rotation axis 62 of the second drum 60. Therefore, the workability of the operation of collecting the magnetic sludge 83 and the oil 81 can be improved.

[0033] In addition, in a workplace where the front-stage separation device 50 has already been introduced, the rear-stage separation device 10 can be easily retrofitted. Since the first drum 20 and the second drum 60 are driven by different motors 25 and 65 respectively, the rotational speeds of the first drum 20 and the second drum 60 can be individually adjusted so as to increase the recovery rate of the magnetic sludge 83 and the oil 81.

[0034] The rear-stage separation device 10 recovers the liquid to be treated 80 in the vicinity of the liquid surface (surface layer portion) of the liquid to be treated 80. There are almost no abrasive grains 82 with a large specific gravity in the surface layer portion. Therefore, it is possible to avoid a part of the abrasive grains 82 remaining in the liquid to be treated 80 recovered by the rear-stage separation device 10. Thereby, the cleanliness of the liquid to be treated 80 can be improved.

[0035] Next, a modified example of the above embodiment will be described. In the above embodiment, in the rear-stage separation device 10, the first drum 20 (FIG. 2) is used to adsorb oil. An endless belt may be used instead of the first drum 20. The outer peripheral surface of the endless belt is immersed in a part of the region of the liquid to be treated 80 flowing through the first flow path 11 and circulates across the liquid surface, similar to the outer peripheral surface 21 of the first drum 20. Thus, it is possible to use a circulating mechanism having a circulating outer peripheral surface such as the first drum 20 and the endless belt.

[0036] In the above embodiment, the container 36 is immersed in the liquid to be treated 80 in the first flow path 11 (FIG. 2), and the liquid to be treated 80 in the surface layer portion is allowed to flow out from the discharge port 37. As the liquid to be treated discharge structure 35, other structures may be used. For example, an opening may be provided in the wall surface of the housing 90 located at the downstream end of the first flow path 11, and the liquid to be treated 80 may be allowed to flow out from the opening. This opening is preferably provided in the vicinity of the height of the liquid surface.

[0037] Next, with reference to FIG. 5, a separation device according to another embodiment will be described. Hereinafter, descriptions of configurations common to the separation devices according to the embodiments shown in FIGS. 1 to 4 will be omitted.

[0038] FIG. 5 is a diagram showing a planar arrangement of the components of the separation device according to the present embodiment. In the embodiments shown in FIGS. 1 to 4, the housing 91 (FIG. 1) of the front-stage separation device 50 and the housing 90 of the rear-stage separation device 10 are separated from each other and are each constituted by an individual housing. In contrast, in the embodiment shown in FIG. 5, the second flow path 51 on the upstream side from the location where the second drum 60 is disposed, and the first flow path 11 on the downstream side from the location where the first drum 20 is disposed, are formed inside a common housing 92. Inside the common housing 92, the first flow path 11 and the second flow path 51 are separated from each other by a partition wall 93.

[0039] Next, the excellent effects of the present embodiment will be described. In the separation device according to the present embodiment, by sharing a part of the housing, it is possible to further reduce the size of the separation device.

[0040] Next, with reference to FIGS. 6 and 7, a separation device according to still another embodiment will be described. Hereinafter, descriptions of configurations common to the separation devices shown in FIGS. 1 to 4 will be omitted.

[0041] FIG. 6 is a diagram showing a planar arrangement of the components of the separation device according to the present embodiment. In the present embodiment, the first flow path 11 and the second flow path 51 are defined inside a common housing 95. The first flow path 11 and the second flow path 51 are separated from each other by a partition wall 96 installed in the housing 95. The partition wall 96 reaches a position higher than the liquid level of the liquid to be treated 80 upward from the bottom surfaces of the first flow path 11 and the second flow path 51.

[0042] In the embodiments shown in FIGS. 1 to 4, the first drum 20 is arranged so as to intersect the first flow path 11, and the other second drum 60 is arranged so as to intersect the second flow path 51. The first drum 20 and the second drum 60 are each rotationally driven by motors 25 and 65, respectively. In contrast, in the present embodiment, the first drum 20 and the second drum 60 are constituted by a single common drum 45. The common drum 45 is rotationally driven by one motor 46.

[0043] The partition wall 96 extends along the flow direction from the downstream end of the first flow path 11 and the upstream end of the second flow path 51, and intersects the common drum 45. At the location where the partition wall 96 intersects the common drum 45, the partition wall 96 is removed according to the cross-sectional shape of the common drum 45. A gap is formed between the edge of the partition wall 96 and the outer peripheral surface of the common drum 45. A gap filler 97 such as felt fills this gap.

[0044] A partition wall 96 is not arranged between the vicinity of the downstream end of the second flow path 51 and the vicinity of the upstream end of the first flow path 11, and the two are connected to each other. The region where the partition wall 96 is not arranged functions as a connection flow path 40 that connects the second flow path 51 to the first flow path 11.

[0045] Both ends of the common drum 45 project beyond the outer side of the side walls 99 of the first flow path 11 and the second flow path 51. The gap between the edge of this side wall 99 and the outer peripheral surface of the common drum 45 is filled with a gap filler 97.

[0046] FIG. 7 is a cross-sectional view of the separation device according to the present embodiment, including the rotation axis of the common drum 45. A part of the inner bottom surface side of the housing 95 is divided into the first flow path 11 and the second flow path 51 by the partition wall 96. The first flow path 11 and the second flow path 51 are each defined between the outer side wall 99 and the partition wall 96.

[0047] A rod 98 is arranged inside the housing 95. The rod 98 is horizontally supported so as to cross the first flow path 11 and the second flow path 51, and extends along the rotation axis of the common drum 45. The rod 98 is fixed to the housing 95.

[0048] The openings at both ends of the common drum 45 are each closed by a disc 47 having an opening provided at the center. The rod 98 passes through the opening of the disc 47. The two discs 47 are rotatably supported on the rod 98 by ball bearings 48. Power is transmitted from the motor 46 to one of the discs 47 via a sprocket and a chain 49. The common drum 45 rotates about the center line of the rod 98 as the rotation axis. Approximately half of the axial direction of the common drum 45 functions as the first drum 20, and the remaining portion functions as the second drum 60.

[0049] The inner cylinder 63 is fixed to the rod 98. A gap is secured between the outer peripheral surface of the inner cylinder 63 and the inner peripheral surface of the common drum 45. Magnets 64 are attached to the outer peripheral surface of the inner cylinder 63 within the range of the second flow path 51.

[0050] The gap between the edge of the partition wall 96 and the outer peripheral surface of the common drum 45 is closed by a gap filler 97. Similarly, the gap between the edge of the side wall 99 and the outer peripheral surface of the common drum 45 is closed by a gap filler 97. The gap fillers 97 are attached to the partition wall 96 and the side wall 99, respectively. For example, felt or the like is used for the gap fillers 97. When the common drum 45 rotates, the outer peripheral surface of the common drum 45 slides against the gap fillers 97.

[0051] Next, the excellent effects of the embodiments shown in FIGS. 6 and 7 will be described. In this embodiment, since the housing of the front-stage separation device 50 and the housing of the rear-stage separation device 10 are integrated, the size of the device can be reduced. Further, the second drum 60 of the front-stage separation device 50 and the first drum 20 of the rear-stage separation device 10 are integrated and configured as a common drum 45 and driven by one motor 46, so that the energy-saving performance can be enhanced.

[0052] Each of the above embodiments is illustrative, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. Regarding the same operational effects due to the same configurations of multiple embodiments, sequential mention will not be made for each embodiment. Furthermore, the present invention is not limited to the above embodiments. For example, it will be obvious to those skilled in the art that various changes, improvements, combinations, etc. are possible.

Explanation of Reference Numerals

[0053] 10 Rear-stage separation device 11 First flow path 12 Inlet 20 First drum 21 Outer peripheral surface of the first drum 22 Rotation axis of the first drum 23 First scraper 24 Oil discharge path 25 Motor 30 Abrasive grain accumulation part 34 Upper and lower separation plate 35 Structure for discharging the liquid to be treated 36 Container 37 Outlet 40 Connection flow path 45 Common drum 46 Motor 47 Disc 48 Ball bearing 49 Sprocket and chain 50 Front-stage separation device 51 Second flow path 52 Inlet 53 Outlet 60 Second drum 61 Outer peripheral surface of the second drum 62 Rotation axis of the second drum 63 Inner cylinder 64 Magnet 65 Motor 67 Roller 73 Second scraper 74 Discharge path 75 Recovery container 80 Liquid to be treated 81 Oil 82 Abrasive grains 83 Magnetic sludge 90, 91 Housing 92 Common housing 93 Partition wall 95 Housing 96 Partition wall 97 Gap filler 98 Rod 99 Side wall outside the first flow path and the second flow path 100 Grinding machine 101 Coolant tank 102 Oil-water separation tank 103 Recovery container 104 Pump

Claims

1. A circulating mechanism having an outer peripheral surface that is immersed in a part of the processing liquid flowing through the first flow path and that circulates across the liquid surface, wherein the processing liquid flowing through the first flow path contains oil having a specific gravity smaller than that of the processing liquid and non-magnetic abrasive grains having a specific gravity larger than that of the processing liquid, and the circulating mechanism that adsorbs the oil floating on the liquid surface and separates it from the processing liquid in the first flow path; A first scraper that removes the oil adsorbed on the outer peripheral surface of the circulating mechanism from the outer peripheral surface of the circulating mechanism; An abrasive grain accumulation part provided on the downstream side of the position where the outer peripheral surface of the circulating mechanism is immersed in the first flow path, and accumulating the abrasive grains contained in the processing liquid flowing through the first flow path; A processing liquid discharge structure provided on the downstream side of the position where the outer peripheral surface of the circulating mechanism is immersed in the first flow path, separating the processing liquid in the first flow path from the abrasive grains contained in the processing liquid, and discharging it from the first flow path; comprising The abrasive grain accumulation part is constituted by a bottom surface lower than the bottom surface of the first flow path; The processing liquid discharge structure is a separation device disposed above the abrasive grain accumulation part.

2. The processing liquid discharge structure is A container that is immersed in the processing liquid in the first flow path, has an upward-facing opening, and into which the processing liquid on the liquid surface flows through the opening; A discharge port that discharges the processing liquid flowing into the container to the outside; The separation device according to claim 1, comprising.

3. A pre-separation device that separates magnetic sludge contained in the processing liquid flowing through the second flow path from the processing liquid using magnetic force; A connection flow path that allows the processing liquid flowing through the second flow path from which the magnetic sludge has been separated to flow into the first flow path on the upstream side of the position where the outer peripheral surface of the circulating mechanism is immersed; The separation device according to claim 1 or 2, further comprising.

4. The circulating mechanism includes a first drum having an outer peripheral surface that is immersed in a part of the processing liquid flowing through the first flow path; The front-stage separation device a second drum that rotates with a magnetic force generated on its outer peripheral surface, with a part of its outer peripheral surface immersed in the liquid to be treated flowing through the second flow path and with a straight line intersecting the flow direction of the second flow path in a plan view as the rotation axis; a second scraper that removes the magnetic sludge adsorbed on the outer peripheral surface of the second drum from the outer peripheral surface of the second drum and includes the rotation axis of the first drum and the rotation axis of the second drum are parallel, or the rotation axis of the second drum is located on an extension line of the rotation axis of the first drum, and the first drum and the second drum rotate in the same rotation direction, The separation device according to claim 3, wherein the oil removed by the first scraper and the magnetic sludge removed by the second scraper are discharged to the same side when viewed from the rotation axes of the first drum and the second drum in a plan view.

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