Floating matter adsorption and recovery device and coolant tank equipped with same

Abstract

A floating matter adsorption and recovery device that improves the floating matter adsorption and recovery rate without requiring major structural changes from conventional oil skimmers, and a tank that has a high purification rate for coolant and enables the coolant to be reused over a long period of time while avoiding spoilage. [Solution] A floating matter adsorption and recovery device comprising an upper roller arranged above the liquid level stored in a liquid storage tank and driven to rotate around the upper roller's rotation axis, a lower roller arranged below the upper roller and configured to be rotatable around the lower roller's rotation axis, an endless circular belt capable of adsorbing floating matter that is suspended between the outer surfaces of the upper roller and the lower roller and rotates around the upper and lower rollers while immersing part of the belt in the liquid when the upper roller is driven to rotate, and a scraper that scrapes off floating matter adsorbed to the belt to the outside of the liquid storage tank, wherein the liquid level entry angle θ of the belt with respect to the liquid level is configured to be an acute angle.

Description

[Technical Field]

[0001] The present invention relates to a floating matter adsorption and recovery device and a coolant tank equipped with the same. [Background technology]

[0002] Processing equipment such as machining centers that process metals and other materials uses large amounts of coolant (cooling liquid) to cool the equipment and workpieces and remove machining debris. The liquid discharged from the processing equipment is primarily coolant, but it can also contain foreign matter such as machine lubricants and cutting debris, which can cause spoilage. For this reason, the liquid discharged from the processing equipment is first sent to a coolant tank, where it is purified by removing foreign matter, and the purified coolant is then supplied to the processing equipment and reused.

[0003] Known coolant tanks include a floating matter adsorption and recovery device. The floating matter adsorption and recovery device, commonly referred to as an oil skimmer, adsorbs floating matter, such as oil, floating on the surface of a liquid. It includes an endless circular belt that adsorbs the floating matter, a drive roller that rotates the belt, and a scraper that scrapes off the floating matter adsorbed to the belt. The belt is rotated while partially immersed in a liquid storage tank that stores waste, causing floating matter on the surface of the liquid to be adsorbed onto the belt. The floating matter adsorbed to the belt is then scraped off by a scraper outside the liquid, recovering the floating matter. This removes foreign matter floating on the surface of the liquid, resulting in purified coolant. Known oil skimmers include those described in Patent Documents 1 and 2 below. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2023-173731

[0005] [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-14127

[0006] The oil skimmer 1 disclosed in Patent Document 1 includes a rotating roller 20 installed outside a tank 2 that stores an oil-containing liquid, a belt 22 that is placed around the rotating roller 20 and at least a portion of which is immersed in the liquid in the tank to collect the oil, a scraper 40 that contacts the belt 22 to scrape off the oil adhering to the belt 22, a recovery unit 30 that recovers the oil scraped off by the scraper 40, and a control unit 52 that controls the drive of the rotating roller 20. In the oil skimmer 1, the belt 22 is suspended around the rotating roller 20, which is disposed above a liquid level 5 of the liquid 4 stored in the tank 2, and a pulley 21, which is disposed below the liquid level 5 (see Figures 2, 7, and 8 of Patent Document 1). The pulley 21 is disposed directly below the rotating roller 20 and has approximately the same diameter as the rotating roller 20, so that the belt 22 enters the liquid 4 approximately perpendicular to the liquid level 5.

[0007] Conventional floating matter adsorption and recovery devices are generally configured, similar to the oil skimmer 1 of Patent Document 1 described above, so that the belt enters the liquid almost perpendicular to the liquid surface, in other words, so that the liquid surface entry angle is approximately 90°. As a result, the contact area between the belt and the floating matter floating on the surface of the liquid, i.e., near the liquid surface, is small, and the floating matter cannot be sufficiently adsorbed by the belt, resulting in a relatively low adsorption and recovery rate of the floating matter. In particular, powdery sludge, including cuttings, mixed in with the floating matter tends to move away from the belt due to impacts generated when the belt enters the liquid surface, making it difficult to adsorb and recover the floating matter on the belt.

[0008] The floating matter recovery device (1) disclosed in the above Patent Document 2 aims to improve the recovery rate of floating matter, and is equipped with a roller chain (10) that runs endlessly between a first position immersed in liquid coolant stored in a storage tank (2) and a second position protruding above the liquid level (L) of the coolant, and a bucket (27) attached to the roller chain that scoops out floating matter as it moves from the first position to the second position.

[0009] The floating matter recovery device (1) of Patent Document 2 attempts to reduce the amount of coolant pumped out while suppressing the outflow of floating matter that has flowed into the bucket (27) by devising a shape and structure for the bucket (27), but compared to conventional oil skimmers that recover floating matter by adsorbing it to a belt, the amount of coolant removed along with the floating matter increases significantly, resulting in a decrease in the amount of coolant available for reuse. Furthermore, it is necessary to use a roller chain instead of a belt and attach many specially shaped buckets, which inevitably leads to a more complex device structure (a major structural change from conventional devices) and an increase in the number of component parts. Summary of the Invention [Problem to be solved by the invention]

[0010] The technology disclosed in this specification aims to solve the above problems and to provide a floating matter adsorption and recovery device that improves the floating matter adsorption and recovery rate without requiring a major structural change from conventional oil skimmers.Furthermore, the technology disclosed in this specification aims to provide a coolant tank that achieves a high coolant purification rate, thereby enabling the coolant to be used repeatedly over a longer period of time while avoiding spoilage. [Means for solving the problem]

[0011] In order to solve the above problems, the floating matter adsorption and recovery device according to the present disclosure includes: A floating matter adsorption and recovery device attached to a liquid storage tank that stores liquid with floating matter on the surface, an upper roller disposed above the liquid level of the liquid stored in the liquid storage tank, the upper roller being driven to rotate around an upper roller rotation axis; a lower roller disposed below the upper roller and configured to be rotatable around a lower roller rotation axis; a belt capable of attracting the floating matter, the belt being an endless loop belt that is stretched between the outer circumferential surface of the upper roller and the outer circumferential surface of the lower roller, and that rotates around the upper roller and the lower roller while a portion of the belt is immersed in the liquid when the upper roller is rotated; a scraper disposed outside the liquid, which scrapes off the floating matter adsorbed to the belt to the outside of the liquid storage tank; Equipped with The belt is configured so that an angle θ of entry into the liquid surface is an acute angle.

[0012] Furthermore, the coolant tank according to the present disclosure includes a liquid storage tank, and is provided with the floating matter adsorption and recovery device according to the present disclosure having the above-described configuration. [Effects of the Invention]

[0013] The floating matter adsorption recovery device of the present disclosure can improve the floating matter adsorption recovery rate, particularly the adsorption recovery rate of powdered sludge, without requiring major structural changes from conventional oil skimmers.

[0014] Furthermore, the coolant tank according to the present disclosure achieves a high coolant purification rate, allowing the coolant to be used repeatedly over a longer period of time while avoiding spoilage. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic partial cross-sectional front view of a floatable matter adsorption and recovery device 20 according to embodiment 1. The floatable matter adsorption and recovery device 20 is attached to a liquid storage tank 10 of a coolant tank 1 that stores a liquid L. [Figure 2] FIG. 2 is an enlarged view of the vicinity of the lower roller 23 including the immersed portion of the belt 25 in the suspended matter adsorption and recovery device 20 of FIG. [Figure 3] 3 is a front view, partially in cross section, of a flotage adsorption and recovery device 220 according to embodiment 2. The flotage adsorption and recovery device 220 is attached to the liquid storage tank 210 of the coolant tank 201. [Figure 4] FIG. 4 is an overall perspective view of the coolant tank 201 to which the floating matter adsorption and recovery device 220 of FIG. 3 is attached. [Figure 5] FIG. 5 is an overall perspective view of a coolant tank 301 equipped with a flotage adsorption and recovery device 320 according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0016] A floatable matter adsorption and recovery device according to an embodiment of the present disclosure will be specifically described below with reference to the drawings. In the following description, the front side of the page in Fig. 1 is the front of the floatable matter adsorption and recovery device, and the left side of the page is the left. Note that the relative dimensions and arrangement of components in each drawing are not necessarily accurate, and some components have been omitted or simplified, or the scale has been changed, for ease of explanation.

[0017] <Embodiment 1> The structure of a flotage adsorption and recovery device 20 according to the first embodiment will be described with reference to FIGS. Fig. 1 is a schematic front view, partially in cross section, of a floatable matter adsorption and recovery device 20 according to embodiment 1. The floatable matter adsorption and recovery device 20 is attached to a liquid storage tank 10 of a coolant tank 1 that stores a liquid L. Fig. 2 is an enlarged view of the vicinity of a lower roller 23, including an immersed portion of a belt 25, in the floatable matter adsorption and recovery device 20 of Fig. 1.

[0018] An example of the liquid L shown in Figure 1 is a coolant discharge liquid discharged after use in a processing device. The liquid L includes a solution layer LB and a floating matter layer LA, which is a layer of floating matter A floating on the solution layer LB. For example, in the case of the coolant discharge liquid, the solution layer LB is mainly composed of coolant, and the floating matter A is mainly composed of machine lubricating oil containing powdery sludge, etc.

[0019] As shown in FIG. 1, the suspended solids adsorption and recovery device 20 includes an upper roller 21. The upper roller 21 is disposed above the liquid level LS of the liquid L stored in the liquid storage tank 10. The upper roller 21 is axially supported by a bearing or the like in a control box 22 installed in the liquid storage tank 10. The upper roller 21 is rotated by an upper roller driving means, for example, built into the control box 22, around an upper roller rotation axis X extending in the horizontal direction. 21 The control box 22 may incorporate not only the upper roller drive means, but also a scraper drive means for driving the scraper and a control mechanism for controlling these drive means. A support plate 24 is attached to the control box 22 for rotatably supporting the lower roller 23, which will be described later.

[0020] As shown in FIG. 1 and other figures, the floating matter adsorption and recovery device 20 includes a lower roller 23. The lower roller 23 is disposed below the upper roller 21, and is aligned with the upper roller rotation axis X 21 The lower roller rotation axis X extends horizontally parallel to 23 Although not limited thereto, the lower roller 23 according to the first embodiment is a driven roller known as a pulley, and the rotational movement of the upper roller 21 is transmitted to the lower roller 23 by a belt 25 described later, so that the lower roller 23 can rotate around the lower roller rotation axis X 23 It is configured to rotate around

[0021] As shown in FIG. 1 and other figures, the floatable matter adsorption and recovery device 20 includes a belt 25. The belt 25 is formed in an endless loop shape and is stretched over the outer circumferential surfaces of the upper roller 21 and the lower roller 23. When the upper roller 21 is driven to rotate, the belt 25 rotates around the upper roller 21 and the lower roller 23 while being partially immersed in the liquid L. At least the outer surface of the belt 25 is made of a material capable of adsorbing floatable matter A contained in the liquid L. The belt 25 can be made of, for example, a nonwoven or woven fabric such as polyethylene terephthalate (PET) or urethane formed into an endless loop of a fixed width. As an example, a belt formed into an endless loop by connecting both ends of a 20 mm wide PET nonwoven fabric tape can be used.

[0022] As shown in FIG. 1 , the floatable matter adsorption and recovery device 20 also includes a scraper 27. The scraper 27 is disposed so as to contact the outer surface of the belt 25 outside the liquid L. The floatable matter adsorption and recovery device 20 is provided with a floatable matter collector 29 below the scraper 27, and the scraper 27 comes into contact with the outer surface of the belt 25 that has adsorbed the floatable matter A, thereby scraping the floatable matter A off the belt 25 into the floatable matter collector 29.

[0023] As shown in FIG. 1, in the first embodiment, the lower roller rotation axis X 23 is the upper roller rotation axis X 21 (in other words, the upper roller rotation axis X 21 and lower roller rotation axis X 23 The plane P containing the liquid is perpendicular to the liquid surface LS.

[0024] Here, the outer circumferential surface of the upper roller 21 on which the belt 25 is wound is connected to the upper roller rotation axis X 21 The distance to the upper roller radius R 21 The lower roller rotation axis X is set to the outer circumferential surface of the lower roller 23 on which the belt 25 is wound. 23 Distance to the lower roller radius R 23 Then, R 21 <R 23is preferable. Lower roller radius R 23 By increasing 23 , the contact area between the floating layer LA of the liquid L and the belt 25 can be increased, and the adsorption recovery rate of the floating matter A can be improved. On the other hand, since the upper roller radius R 21 has no effect on the adsorption recovery rate of the floating matter A, in order to avoid an increase in the overall size of the apparatus, it is preferably maintained as small as possible. For example, for the upper roller radius R 21 and the lower roller radius R 23 , the ratio (R 23 / R 21 ) can be set to 1.2 < (R 23 / R 21 ) < 5.0, and it may also be set to 2.0 < (R 23 / R 21 ). As an example, the upper roller radius R 21 can be 15 mm, and the lower roller radius R 23 can be 50 mm.

[0025] As shown in FIG. 2, in the first embodiment, the lower roller rotation axis X 23 is arranged such that the height H from the liquid surface LS satisfies 0 < H < R 23 . Thus, since 0 < H, that is, the lower roller rotation axis X 23 is arranged above the liquid surface, the liquid surface entry angle θ of the belt 25 into the liquid surface LS (that is, the angle of the tangent TL at the intersection point TP of the liquid surface LS shown in FIG. 2 and the outer surface of the belt 25 with respect to the liquid surface LS) can be made an acute angle. Further, since H < R 23 , the belt 25 wound around the outer peripheral surface of the lower roller 23 rotates while being partially immersed in the liquid L. As an example, when the lower roller radius R 23 is 50 mm, the height H can be 40 mm.

[0026] Here, if the thickness (depth) of the floating layer LA is DA, it is preferable that 1 < (R 23 - H) / DA, more preferably 2 < (R 23 - H) / DA < 20, and even more preferably 3 < (R 23It is more preferable that (R −H) / DA<10. 23 If (R −H) / DA is too small, when the amount of liquid L such as discharged liquid flowing into the liquid storage tank 10 changes and the liquid level LS rises and falls, the belt 25 may not be immersed in the liquid L. 23 If (R -H) / DA is too large, the belt 25 will be immersed deep in the liquid L, and the section passing through the solution layer LB below the suspended matter layer LA will be long, and the suspended matter A adsorbed to the belt 25 when it enters the liquid surface LS will be detached while passing through the solution layer LB, which may result in a decrease in the recovery rate of the suspended matter A. The expected amount of vertical movement of the liquid surface LS and the thickness DA of the suspended matter layer LA will vary depending on the type of liquid L received in the liquid storage tank 10 and the dimensions and shape of the liquid storage tank 10, but as an example, in a case where the thickness DA is expected to be about 2 mm±1 mm, (R 23 -H) to about 10 mm.

[0027] Next, the operation of the flotage adsorption and recovery device 20 will be described. Below, we will explain the case where the upper roller 21 is driven to rotate the belt 25 of the floating matter adsorption and recovery device 20 counterclockwise, as shown by the arrow in Figure 1, and the belt 25 enters the liquid surface LS from left to right.

[0028] The liquid L injected into the liquid storage tank 10 of the coolant tank 1 to which the floating matter adsorption and recovery device 20 of this embodiment 1 is attached separates into a floating matter layer LA consisting of machine lubricating oil, etc. and a solution layer LB consisting of coolant, etc. due to differences in specific gravity, for example, when stored in the liquid storage tank 10 for a while.

[0029] When the upper roller driving means is driven and the upper roller 21 is driven to rotate counterclockwise, the belt 25 rotates and enters the liquid L at the intersection TP with the liquid surface LS. In this case, in the floatable matter adsorption and recovery device 20 according to the first embodiment, the liquid surface entry angle θ of the belt 25 is configured to be an acute angle, as described above. In conventional oil skimmers, the liquid surface entry angle θ of the belt is approximately 90°, so that the belt enters the liquid surface almost perpendicularly. Impacts and fluctuations on the liquid surface when the belt enters the liquid surface have been observed to cause some of the floatable matter to "escape" away from the intersection point TP, where the belt enters the liquid surface. In contrast, in the floatable matter adsorption and recovery device 20 according to the first embodiment, the belt 25 enters along the floatable matter layer LA at a smaller liquid surface entry angle θ. This reduces resistance and impacts when the belt 25 enters the liquid surface LS, thereby reducing the escape of floatable matter A from the intersection point TP due to impacts, particularly the escape of powdery sludge in the floatable matter A. As the belt 25 smoothly enters the liquid surface LS, the floating matter A near the liquid surface LS does not move away from the intersection point TP, but rather moves in the same direction (from left to right in Figure 2) as if being attracted from the intersection point TP to the belt 25, and is easily adsorbed by the belt 25.

[0030] The belt 25 that has entered the liquid L passes through the floating matter layer LA at an angle. This makes it possible to increase the contact area between the belt 25 and the floating matter layer LA compared to when the belt 25 passes through the floating matter layer LA in a vertical direction. Furthermore, by the belt 25 passing through the floating matter layer LA at an angle rather than vertically, the floating matter A floating below the belt 25 is pressed against the surface of the belt 25 by buoyancy.

[0031] After passing through the suspended matter layer LA, the belt 25 then passes obliquely, not vertically, through the solution layer LB below the suspended matter layer LA. Therefore, even if suspended matter A that has been adsorbed to the belt 25 is desorbed from the belt 25 in the solution layer LB, suspended matter A floating near the desorption point is likely to rise due to buoyancy and be guided to the surface of the belt 25 and be re-adsorbed.

[0032] After passing through the solution layer LB, the belt 25 leaves the liquid L at an angle, not perpendicular to the liquid surface LS. This reduces the resistance and impact during separation compared to when the belt 25 leaves perpendicularly, and is expected to reduce the amount of floating matter A that detaches from the belt 25 during separation.

[0033] As a result of the above, according to the floating matter adsorption and recovery device 20 of this embodiment 1, the belt 25 can be separated from the liquid surface LS while adsorbing more floating matter A than conventional oil skimmers.

[0034] The liquid surface entry angle θ is preferably 15°<θ<85°, more preferably 45°<θ<75°, and most preferably about 60°. In the first embodiment, if the liquid surface entry angle θ is small, the depth of entry of the belt 25 into the liquid L is small, and therefore, when the amount of the liquid L, such as the discharge liquid flowing into the liquid storage tank 10, changes and the liquid level LS drops, the belt 25 may not be immersed in the liquid L. On the other hand, if the liquid surface entry angle θ is large, the effect of reducing the impact when the belt 25 enters the liquid level LS is reduced, and further, the effect of increasing the contact area between the belt 25 and the suspended matter layer LA and the effect of improving the adsorption rate of the suspended matter A due to buoyancy are also reduced.

[0035] In addition, the upper roller radius R 21 <Lower roller radius R 23 as the lower roller radius R 23 By making the upper roller radius R relatively large, it is possible to accommodate a relatively wide range of up and down movements of the liquid surface LS, while lengthening the section in which the belt 25 passes through the suspended matter layer LA, thereby increasing the contact area. 21 By keeping the size as it is, it is possible to avoid the entire flotage adsorption and recovery device 20 from becoming larger.

[0036] The floating matter A adsorbed by the belt 25 that has separated from the liquid surface LS rises counterclockwise toward the upper roller 21 as the belt 25 rotates. 21 <Lower roller radius R 23 As a result, the belt 25 that has attracted the floating matter A moves not vertically but obliquely so as to support the floating matter A from below. Therefore, it can be expected that the floating matter A is prevented from being desorbed from the belt 25 outside the liquid L.

[0037] The belt 25, which has adsorbed the floating matter A, winds around the upper roller 21 and then reaches the scraper 27. The floating matter A adsorbed to the surface of the belt 25 is then scraped off by the scraper 27 into the floating matter collector 29 and collected. As described above, by the time the belt 25 reaches the scraper 27, it has adsorbed a larger amount of floating matter A than conventional oil skimmers, and an improved collection rate of floating matter A is expected. The belt 25 from which the floating matter A has been desorbed continues to descend and enters the liquid L at the intersection TP with the liquid surface LS. In this way, by repeating the process of adsorbing and collecting the floating matter A, the floating matter A can be effectively removed from the liquid L and purified.

[0038] As described above, the floating matter adsorption and recovery device 20 according to the first embodiment can improve the adsorption and recovery rate of the floating matter A without making any major structural changes to the conventional oil skimmer. Furthermore, the coolant tank 1 equipped with such a floating matter adsorption and recovery device 20 can purify the liquid L more efficiently.

[0039] Next, the main configuration and effects of the flotage adsorption and recovery device 20 according to the first embodiment will be explained again. The floating matter adsorption and recovery device 20 according to the first embodiment includes: A floating matter adsorption and recovery device (20) attached to a liquid storage tank (10) that stores a liquid (L) with floating matter (A) floating on its surface, The upper roller 21 is disposed above the liquid level LS of the liquid L stored in the liquid storage tank 10, and the upper roller rotation axis X 21 an upper roller 21 driven to rotate around The lower roller 23 is disposed below the upper roller 21, and the lower roller rotation axis X 23 a lower roller 23 configured to be rotatable around the lower roller 23; an endless loop-shaped belt 25 capable of attracting floating matter A, the belt 25 being stretched over the outer circumferential surface of the upper roller 21 and the outer circumferential surface of the lower roller 23, and rotating around the upper roller 21 and the lower roller 23 while a portion of the belt 25 is immersed in the liquid L when the upper roller 21 is rotated; a scraper 27 disposed outside the liquid L, which scrapes off the floating matter A adsorbed on the belt 25 to the outside of the liquid storage tank 10; Equipped with The belt 25 is configured so that the angle θ of entry into the liquid surface LS is an acute angle.

[0040] According to the above configuration, the belt 25 enters the liquid surface LS at an acute angle, thereby reducing the impact of the belt 25 entering the liquid surface LS and reducing the escape of the floating matter A, particularly the escape of sludge such as cuttings in the floating matter A. As the belt 25 smoothly enters the liquid surface LS, the floating matter A near the liquid surface LS does not move away from the entry point of the belt 25, but rather moves in the same direction as the belt 25 (from left to right in FIG. 2 ) and is attracted to and approaches the belt 25. Furthermore, since the belt 25 that has entered the liquid L passes obliquely through the floating matter layer LA, the contact area between the belt 25 and the floating matter layer LA is increased compared to when passing vertically, and the floating matter A floating below the belt 25 is pressed against the surface of the belt 25 by buoyancy. Furthermore, since the belt 25 also passes obliquely through the solution layer LB, even if floating matter A that has been adsorbed to the belt 25 is desorbed from the belt 25 in the solution layer LB, the floating matter A floating near the desorption point rises due to buoyancy and is guided to the surface of the belt 25, where it is likely to be re-adsorbed. As a result, it is possible to adsorb more floating matter A onto the belt 25 than with conventional oil skimmers. Therefore, the floating matter adsorption and recovery device according to the first embodiment can improve the adsorption and recovery rate of floating matter without requiring a major structural change from conventional oil skimmers.

[0041] In the floating matter adsorption and recovery device 20 according to the first embodiment, the lower roller rotation axis X 23is located above the liquid level LS (i.e., the lower roller rotation axis X 23 The height H from the liquid level LS is greater than 0).

[0042] According to the above configuration, the liquid surface entry angle θ can be set to an acute angle (i.e., 0°<θ<90°) by simply changing the height at which the lower roller is positioned in a conventional oil skimmer.

[0043] In the floating matter adsorption and recovery device 20 according to the first embodiment, the radius R of the lower roller 23 is the radius of the upper roller R 21 is greater than (i.e., R 21 <R 23 (It is).

[0044] According to the above configuration, the contact area between the suspended matter layer LA of the liquid L and the belt 25 can be increased while preventing the entire suspended matter adsorption and recovery device 20 from becoming large, thereby improving the adsorption and recovery rate of the suspended matter A.

[0045] The coolant tank 1 according to the first embodiment is provided with the floating matter adsorption and recovery device 20 having the above-described configuration.

[0046] The coolant tank 1 having the above configuration can improve the purification rate of the coolant compared to conventional coolant tanks, and allows the coolant to be used repeatedly for a longer period of time while avoiding spoilage.

[0047] <Embodiment 2> Next, the structures of the flotage adsorption and recovery device 220 and the coolant tank 201 according to the second embodiment will be described with reference to FIGS. Fig. 3 is a partial cross-sectional front view schematically showing a floatable matter adsorption and recovery device 220 according to embodiment 2. The floatable matter adsorption and recovery device 220 is attached to a liquid storage tank 210 of a coolant tank 201. Fig. 4 is an overall perspective view of the coolant tank 201 to which the floatable matter adsorption and recovery device 220 of Fig. 3 is attached.

[0048] The floating matter adsorption and recovery device 220 according to the second embodiment is different from the floating matter adsorption and recovery device 20 according to the first embodiment only in the structure and arrangement of the lower roller 223. Further, the liquid storage tank 210 of the coolant tank 201 is configured such that the liquid L stored therein flows generally in one direction F. In the following, for the components having the same configuration as those in the first embodiment, the same reference numerals as those in the first embodiment are given, and the description thereof is omitted.

[0049] As shown in FIG. 3 and the like, the lower roller 223 according to the second embodiment has a lower roller rotation axis X 223 which is arranged at a position shifted to the right instead of directly below the upper roller rotation axis X 21 . In other words, the plane P including the upper roller rotation axis X 21 and the lower roller rotation axis X 223 intersects the liquid surface LS at an angle α where α≠90°, which is significantly different from the lower roller 23 according to the first embodiment. The lower roller 223 has the same lower roller radius R 21 as the upper roller radius R 223 (R 21 = R 223 ). Therefore, the angle α at which the plane P intersects the liquid surface LS is equal to the liquid surface entry angle θ at which the belt 25 enters the liquid surface LS (α = θ). Further, in the second embodiment, the lower roller rotation axis X <​​​​​​​​​​​​​​​​​​Here, in the coolant tank 201, a flow path is formed in the liquid storage tank 210, along a direction F indicated by the white arrow in FIGS. 3 and 4. The coolant tank 201 shown in FIG. 4 includes, in addition to the liquid storage tank 210, a processing device connection unit 230 formed above the liquid storage tank 210, a filter roller 250, and a purified liquid supply unit 270. The processing device connection unit 230 includes an inlet opening 231 capable of receiving liquid L, and an outlet opening 233 formed below the inlet opening 231 and fluidly connected to the inlet opening 231. The liquid L can flow down inside the processing device connection unit 230 from the inlet opening 231 toward the outlet opening 233. When the inlet opening 231 is connected to a processing device and the liquid L is discharged from the processing device, the liquid L flows into the coolant tank 201 from the inlet opening 231, as indicated by the white arrow in FIG. 4. The liquid L flows down the inside of the processing device connecting portion 230 and passes through the inside of the filter roller 250 attached to the outlet opening 233, where relatively large foreign matter in the liquid L is removed. The liquid L filtered through the filter roller 250 is guided by the wall surface of the liquid storage tank 210, etc., so as to flow around the processing device connecting portion 230 in one direction F (counterclockwise in FIG. 4), as indicated by the outlined arrow in FIG. 4. A purified liquid supply unit 270 equipped with a liquid intake pump is provided at the final destination of the flow path of the liquid L in the liquid storage tank 210, and a suspended matter adsorption and recovery device 220 is attached immediately before the purified liquid supply unit 270. In this way, the liquid L is configured so that it flows through a long flow path along the outer wall of the liquid storage tank 210 before reaching the suspended matter adsorption and recovery device 220. This configuration makes it easy for the liquid L to separate into a suspended matter layer LA and a solution layer LB in the coolant tank 201 before reaching the suspended matter adsorption and recovery device 220. Furthermore, by providing a floating matter adsorption and recovery device 220 immediately before the purified liquid supply section 270, the probability that the liquid L will pass near the floating matter adsorption and recovery device 220 before being taken from the purified liquid supply section 270 for reuse is increased, and the system is configured to efficiently remove most of the floating matter A from the liquid L.

[0052] Here, the suspended matter adsorption and recovery device 220 is installed so that the "one direction F (from left to right in the second embodiment)" in which the liquid L flows in the liquid storage tank 210 is the same as the direction in which the belt 25 enters the liquid surface LS. In other words, the belt 25 enters the liquid surface LS so as to proceed forward in the one direction F in which the liquid L flows, passes through the suspended matter layer LA and the solution layer LB along the one direction F, and then leaves the liquid surface LS.

[0053] In the floating matter adsorption and recovery device 220 according to the second embodiment, the upper roller rotation axis X 21 and lower roller rotation axis X 223 extend horizontally parallel to each other, and the lower roller rotation axis X 223 is the upper roller rotation axis X 21 In other words, the lower roller rotation axis X 223 and upper roller rotation axis X 21 extend in the same plane P that intersects the liquid surface at an angle α, where α≠90°.

[0054] According to the above configuration, the lower roller rotation axis X 223Even if the belt 25 is positioned above the liquid level LS, the belt 25 can be made to enter the liquid level LS at a liquid level entry angle θ in the range of 0°<θ<90°. Because the belt 25 enters the liquid level LS at an acute angle, impacts and the like caused by the belt 25 entering the liquid level LS are reduced, as in the first embodiment, and the escape of the floating matter A, particularly the escape of powdery sludge in the floating matter A, due to impacts and the like is reduced. Because the belt 25 smoothly enters the liquid level LS, the floating matter A near the liquid level LS does not move away from the entry point of the belt 25 but rather moves in the same direction as the belt 25, being attracted to and approaching the belt 25. Furthermore, since the belt 25 enters the liquid L and passes through the floating matter layer LA at an angle, the contact area between the belt 25 and the floating matter layer LA is increased compared to when passing vertically, and the floating matter A floating below the belt 25 is pressed against the surface of the belt 25 by buoyancy. Furthermore, since the belt 25 also passes obliquely through the solution layer LB, even if the floating matter A that has been adsorbed to the belt 25 is desorbed from the belt 25 in the solution layer LB, the floating matter A floating near the desorption point rises due to buoyancy and is guided to the surface of the belt 25, where it is likely to be re-adsorbed. As a result, the floatable matter adsorption and recovery device 220 according to the second embodiment also makes it possible to adsorb more floatable matter A onto the belt 25 than conventional oil skimmers. In this way, the floatable matter adsorption and recovery device 220 can also improve the adsorption and recovery rate of the floating matter without requiring a major structural change from conventional oil skimmers.

[0055] According to the configuration of the second embodiment, by adjusting the height H of the lower roller 223 from the liquid surface LS, the range of response to the up and down movement of the liquid surface LS can be adjusted by adjusting the radius R of the lower roller. 223 It can be set without being restricted by Furthermore, the belt 25, which has adsorbed the floating matter A and separated from the liquid surface LS, moves obliquely so as to support the floating matter A from below, rather than vertically as in the first embodiment. Therefore, it is also expected to have an effect of suppressing the detachment of the floating matter A from the belt 25 outside the liquid L.

[0056] Furthermore, in the coolant tank 201 according to this second embodiment, the liquid storage tank 210 is configured so that the liquid L stored therein flows in one direction F at the portion where a portion of the belt 25 enters the liquid surface LS, and the portion of the belt 25 is configured to enter the liquid surface LS along the one direction F.

[0057] According to the above configuration, when belt 25 enters liquid surface LS, it enters along the flow of liquid L, so that floating matter A, especially sludge, is guided to the vicinity of belt 25 and becomes easy to adsorb to belt 25. As a result, the adsorption and recovery rate of floating matter A by floatable matter adsorption and recovery device 220 is further improved, and in turn, the purification rate of coolant in coolant tank 201 is further improved, and it becomes possible to repeatedly use coolant for a longer period of time while avoiding spoilage.

[0058] <Other embodiments> The technology disclosed in this specification is not limited to the above-described embodiment, and the following, for example, is also included in the technical scope of the present disclosure.

[0059] (1) In the first embodiment, the lower roller rotation axis X 23 The upper roller rotation axis X 21 In the second embodiment, the lower roller rotation axis X 223 The upper roller rotation axis X 21 5, in the floating matter adsorption and recovery device 320 attached to the liquid storage tank 310 of the coolant tank 301, the lower roller rotation axis X of the lower roller 323 The upper roller rotation axis X 21 Alternatively, the liquid level LS may be shifted from directly below the liquid level LS.

[0060] (2) In the above embodiment, the floating matter adsorption and recovery device is attached to a coolant tank to purify the discharged liquid from a processing device that is primarily composed of coolant. However, this is not limited to this. The floating matter adsorption and recovery device according to the present disclosure can be widely applied to adsorb and recover floating matter from a liquid having floating matter on the surface. In the above embodiment, the floating matter is oil containing cutting chips. However, the floating matter may be, for example, composed only of powdery solids or only of a liquid with a relatively low specific gravity.

[0061] (3) In the above embodiment, the upper roller is driven to rotate by a driving means, and the lower roller is a driven pulley, but this is not limiting. Both rollers may be driven by a driving means, or the lower roller may be driven to rotate and the upper roller may be a pulley.

[0062] While the preferred embodiments of the floating matter adsorption and recovery device and coolant tank according to the present disclosure have been described above, these are merely examples and are not intended to limit the scope of the invention. The embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. [Explanation of symbols]

[0063] 1,201,301...Coolant tank 10,210,310…Liquid storage tank 20, 220, 320...Floating matter adsorption and recovery device 21...Upper roller R 21 …Upper roller radius X 21 …Upper roller rotation axis 22...Control box 23,223,323…Lower roller R 23 ,R 223 …Lower roller radius X 23 ,X 223 ,X 323 …Lower roller rotation shaft 24...Support plate 25...Belt 27...Scraper 29...Floating matter collector 22...Control box 230... Processing device connection part 231...Entrance opening 233...Exit opening 250...Filter roller 270...Purification liquid supply unit L…liquid LS…Liquid level LA: Floating matter layer (lubricating oil mixed with cuttings, etc.) LB: Solution layer (coolant, etc.) A...floating matter H...Height (from the liquid surface of the lower roller rotation axis) F...One direction (flow of liquid L)

Claims

1. A floating matter adsorption and recovery device attached to a liquid storage tank that stores liquid with floating matter on the surface, an upper roller disposed above the liquid level of the liquid stored in the liquid storage tank, the upper roller being driven to rotate around an upper roller rotation axis; a lower roller disposed below the upper roller and configured to be rotatable around a lower roller rotation axis; a belt capable of attracting the floating matter, the belt being an endless loop belt that is stretched between the outer circumferential surface of the upper roller and the outer circumferential surface of the lower roller, and that rotates around the upper roller and the lower roller while a portion of the belt is immersed in the liquid when the upper roller is rotated; a scraper disposed outside the liquid, which scrapes off the floating matter adsorbed to the belt to the outside of the liquid storage tank; Equipped with The belt is configured so that a liquid surface entry angle θ of the belt to the liquid surface is 0°<θ<90°, The lower roller rotation shaft is disposed above the liquid surface, A suspended solids adsorption and recovery device, wherein the radius of the lower roller is larger than the radius of the upper roller.

2. The floating matter adsorption and recovery device described in claim 1, wherein the upper roller rotation axis and the lower roller rotation axis extend horizontally parallel to each other, and the lower roller rotation axis is positioned shifted from directly below the upper roller rotation axis.

3. A coolant tank comprising the liquid storage tank and the floating matter adsorption and recovery device according to claim 1 or 2 attached thereto.

4. 4. The coolant tank according to claim 3, wherein the liquid storage tank is configured so that the liquid stored therein flows in one direction at a portion where the portion of the belt enters the liquid surface, and the portion of the belt is configured to enter the liquid surface along the one direction.

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