Water acquisition unit and circulation system

Abstract

Reduce the amount of water make-up in the circulation system. [Solution] A water acquisition unit for acquiring water from debris removed from a waste liquid containing the debris includes a water recovery section that recovers water released from the debris removed from the waste liquid by electrophoresis, and a return flow path for mixing the recovered water with one or both of the waste liquid from which the debris has been removed and the waste liquid before the debris has been removed. Preferably, the water recovery section includes a stripping section that peels off the debris attached to an electrode by electrophoresis from the electrode, and a separation section that separates the water from a fluid containing water vapor generated from the debris peeled off from the electrode by the stripping section. More preferably, the separation section includes one or more of a centrifugal separator having a cyclone flow path through which the fluid flows, a crank flow path section having a crank flow path through which the fluid flows, and a mesh plate having a plurality of holes through which the fluid flows.

Description

[Technical Field]

[0001] The present invention relates to a circulation system that processes waste liquid discharged from a processing device that performs processing using a processing liquid, produces processing liquid from the waste liquid, and sends the processing liquid to the processing device.The present invention relates to a water acquisition unit that acquires water from processing debris removed from the waste liquid and returns it to the circulation system, and a circulation system that incorporates this water acquisition unit. [Background technology]

[0002] The device chip manufacturing process uses a wafer on which devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integration) are formed in multiple areas defined by multiple planned dividing lines (streets) arranged in a grid pattern. By dividing this wafer along the planned dividing lines, multiple device chips each equipped with a device are obtained. A cutting device that cuts the wafer with an annular cutting blade is used to divide the wafer.

[0003] In recent years, as electronic devices have become smaller and thinner, there has been a demand for thinner device chips. Therefore, before dividing the wafer, a process of grinding the backside of the wafer is sometimes performed to thin the wafer. Wafer thinning is performed using a grinding device that grinds the wafer with a grinding wheel equipped with multiple grinding stones.

[0004] When processing wafers using the above-mentioned cutting and grinding devices, a processing fluid such as pure water is supplied to the wafer. This processing fluid cools the wafer and processing tools (cutting blades, grinding wheels, etc.) and washes away debris (processing debris) generated during processing. The used processing fluid is then discharged outside the processing device as waste liquid and disposed of.

[0005] However, because machining equipment uses large amounts of machining fluid, disposing of all used machining fluid as waste fluid would result in enormous disposal costs. Therefore, a circulation system has been proposed that purifies and recycles waste fluid discharged from machining equipment. In this circulation system, water is circulated between a water reclamation device and the machining equipment. This circulation system eliminates the need to continuously supply new machining fluid to the circulation system, and also eliminates the need to continuously discharge waste fluid.

[0006] When waste liquid is reused as a machining fluid, impurities are removed from the waste liquid. For example, the waste liquid is purified by recovering the processing debris contained in the waste liquid using electrophoresis (see Patent Documents 1, 2, and 3). The water produced by purifying the waste liquid undergoes further regeneration treatment and is then sent to the processing equipment again for use as a machining fluid. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2022-89048 [Patent Document 2] Japanese Patent Publication No. 2021-100038 [Patent Document 3] Patent Publication No. 2021-146418 Summary of the Invention [Problem to be solved by the invention]

[0008] When electrophoresis is performed, machining debris precipitates on the electrode. Therefore, the electrode is periodically pulled out of the waste liquid, and the machining debris adhering to the electrode is removed from the electrode. The machining debris removed from the electrode contains a significant amount of water that was contained in the waste liquid. In other words, water is removed along with the machining debris in the process of removing the machining debris from the waste liquid, so water is gradually lost from the machining fluid circulation system. For this reason, it was necessary to periodically replenish water in this circulation system.

[0009] One method for supplying large amounts of water to a circulation system is to supply water from the factory where the processing equipment is located. However, this requires the preparation of supply pipes and pumps, which not only incur costs but also consume limited space inside the factory. If the amount of water to be supplied to the circulation system is small, a method can be adopted in which workers periodically put water in containers and carry it to the circulation system.

[0010] The present invention has been made in consideration of such problems, and aims to provide a water acquisition unit that can reduce the amount of water replenished to a circulation system from the outside, and a circulation system incorporating this water acquisition unit. [Means for solving the problem]

[0011] According to one aspect of the present invention, there is provided a water acquisition unit that acquires water from processing debris removed from a waste liquid containing the processing debris, the water acquisition unit comprising: a water recovery section that recovers water released from the processing debris removed from the waste liquid by electrophoresis; and a return flow path for mixing the water recovered in the water recovery section with either or both of the waste liquid from which the processing debris has been removed and the waste liquid before the processing debris has been removed.

[0012] Preferably, the device further includes an on-off valve provided in the return flow path.

[0013] Preferably, the water recovery unit includes a peeling unit that peels off the processing debris that has adhered to the electrode by electrophoresis from the electrode, and a separation unit that separates the water from a fluid containing water vapor generated from the processing debris that has been peeled off from the electrode by the peeling unit.

[0014] The separation section has one or more of a centrifugal separation section having a cyclone flow path through which the fluid flows, a crank flow path section having a crank flow path through which the fluid flows, and a mesh plate having a plurality of holes through which the fluid flows.

[0015] The water recovery unit further includes a heating unit that heats the processing waste separated from the electrode by the separating unit.

[0016] The water recovery section further includes a cooling section for cooling the fluid.

[0017] According to another aspect of the present invention, there is provided a circulation system that processes waste liquid containing processing debris discharged from a processing device that processes a workpiece, produces a processing liquid from the waste liquid, and sends the processing liquid to the processing device, the circulation system comprising: a processing debris removal section that removes the processing debris from the waste liquid by electrophoresis; the above-mentioned water acquisition unit that acquires water from the processing debris removed by the processing debris removal section; and a processing liquid generation section that generates a processing liquid from the waste liquid from which the processing debris has been removed by the processing debris removal section and water recovered by the water recovery section of the water acquisition unit, and the processing liquid generated by the processing liquid generation section is supplied to the processing device. [Effects of the Invention]

[0018] A water acquisition unit according to one aspect of the present invention, and a circulation system incorporating the water acquisition unit, acquires water from processing debris removed from a waste liquid. Specifically, the water acquisition unit includes a water recovery section that recovers water released from the processing debris removed from the waste liquid by electrophoresis, and a return flow path for mixing the water recovered in the water recovery section with either or both of the waste liquid from which the processing debris has been removed and the waste liquid before the processing debris has been removed.

[0019] Therefore, when the processing debris is removed from the waste liquid, the water removed along with the processing debris is recovered from the processing debris and returned to the waste liquid. That is, in a circulation system that regenerates waste liquid discharged from a processing device and supplies it to the processing device as processing liquid, less water is lost as the processing debris is removed from the waste liquid. In this case, only a small amount of water needs to be replenished to the circulation system from outside.

[0020] Therefore, according to one aspect of the present invention, there is provided a water acquisition unit that can reduce the amount of water that is replenished to a circulation system from the outside, and a circulation system incorporating this water acquisition unit. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view schematically illustrating an outline of a circulation system. [Figure 2] FIG. 2 is a cross-sectional view schematically showing a water acquisition unit. [Figure 3] FIG. 2 is a cross-sectional view schematically illustrating an example of a separation unit. [Figure 4] FIG. 10 is a cross-sectional view schematically showing another example of the separation section. [Figure 5] FIG. 10 is a cross-sectional view schematically showing yet another example of the separation section. DETAILED DESCRIPTION OF THE INVENTION

[0022] An embodiment of the present invention will be described below with reference to the accompanying drawings. First, a circulation system incorporating a water acquisition unit according to this embodiment will be described. The circulation system is connected to a processing device that processes workpieces such as semiconductor wafers, and has the function of treating waste liquid discharged from the processing device to generate processing liquid and supplying it to the processing device. FIG. 1 is a perspective view schematically showing a circulation system 40 and a processing device 2.

[0023] There is no limit to the type of processing device that can be connected to the circulation system. Examples of processing devices include a cutting device equipped with a processing unit (cutting unit) that cuts the workpiece 1 with an annular cutting blade, a grinding device equipped with a processing unit (grinding unit) that grinds the workpiece 1 with a grinding wheel to which multiple grinding wheels are fixed, and a polishing device equipped with a processing unit (polishing unit) that polishes the workpiece 1 with a polishing pad.

[0024] For example, a silicon wafer on which devices such as ICs and LSIs are formed in a plurality of areas partitioned by a plurality of planned dividing lines (streets) arranged in a grid pattern is processed by a processing device as the workpiece 1. After this silicon wafer is thinned by a grinding device and a polishing device, it is divided along the planned dividing lines by a cutting device to manufacture a plurality of thinned device chips each equipped with a device.

[0025] The workpiece 1 processed by the processing apparatus is not limited to a silicon wafer. For example, the workpiece 1 may be formed of other semiconductor materials (GaAs, InP, GaN, etc.), sapphire, glass, ceramics, resin, composite oxides (LiNbO3, LiTaO3), etc. Furthermore, there are no restrictions on the type, number, shape, structure, size, arrangement, etc. of devices formed on the workpiece 1, and the workpiece 1 does not necessarily have to have any devices formed thereon.

[0026] When processing the workpiece 1, a protective tape 3 may be attached in advance to protect the surface (back surface 1b) of the workpiece 1 that is not to be processed. The protective tape 3 protects the surface of the workpiece 1 that is not to be processed from impacts that may be applied when the surface of the workpiece 1 is processed or when the workpiece 1 is transported, and prevents damage to the workpiece 1.

[0027] The protective tape 3 has a flexible film-like substrate and a glue layer (adhesive layer) formed on one side of the substrate. For example, the substrate may be made of polyolefin, polyethylene terephthalate, polyvinyl chloride, polystyrene, or the like. The glue layer (adhesive layer) may be made of, for example, silicone rubber, an acrylic material, or an epoxy material.

[0028] 1 will be described as an example of the processing device 2 that processes the workpiece 1. However, the processing device 2 to which the circulation system 40 is connected is not limited to the grinding device.

[0029] The processing device (grinding device) 2 has a base 4 that supports each component. An opening is provided on the top surface of the base 4. An X-axis moving table 8 is provided inside the opening, and a holding unit (holding table) 6 that holds the workpiece 1 by suction is placed on its top surface. The X-axis moving table 8 can be moved in the X-axis direction by an X-axis moving mechanism (not shown). The X-axis moving mechanism functions to position the X-axis moving table 8 between a loading / unloading area 10 where the workpiece 1 is loaded / unloaded on the holding unit 6 and a processing area 12 where grinding of the workpiece 1 held by the holding unit 6 is carried out.

[0030] A disk-shaped porous member having the same diameter as the workpiece 1 is exposed on the upper surface of the holding unit 6. The upper surface of the holding unit 6 serves as a holding surface 6a that holds the workpiece 1. The holding unit 6 has an internal suction path (not shown) with one end connected to the porous member and the other end connected to a suction source (not shown). When the suction source is activated, negative pressure acts on the workpiece 1 placed on the holding surface 6a, and the workpiece 1 is sucked and held by the holding unit 6.

[0031] A processing unit (grinding unit) 14 that processes (grinds) the workpiece 1 is disposed above the processing area 12. A support part 16 is erected at the rear end of the base 4 of the processing device 2, and this support part 16 supports the processing unit 14. A pair of Z-axis guide rails 18 extending in the Z-axis direction are provided on the front surface of the support part 16, and a Z-axis moving plate 20 is slidably attached to each Z-axis guide rail 18.

[0032] A nut portion (not shown) is provided on the back side (rear side) of the Z-axis moving plate 20, and a Z-axis ball screw 22 parallel to the Z-axis guide rail 18 is threadedly engaged with this nut portion. A Z-axis pulse motor 24 is connected to one end of the Z-axis ball screw 22. When the Z-axis pulse motor 24 rotates the Z-axis ball screw 22, the Z-axis moving plate 20 moves in the Z-axis direction along the Z-axis guide rail 18. The machining unit 14 is fixed to the lower front side of the Z-axis moving plate 20. When the Z-axis moving plate 20 is moved in the Z-axis direction, the machining unit 14 can be moved in the Z-axis direction.

[0033] The processing unit 14 includes a spindle 28 that is rotated by a motor connected to the base end, and a grinding wheel (processing tool) 32 that is fixed to a mount 30 disposed on the tip end of the spindle 28. The motor is provided inside the spindle housing 26, and when the motor is operated, the grinding wheel 32 rotates in accordance with the rotation of the spindle 28. The holding unit 6 is also connected to a rotation drive source such as a motor, and can rotate around a rotation axis that is perpendicular to the holding surface 6a.

[0034] The grinding wheel 32 has an annular base with a concave annular groove formed on one end face (lower face). The annular base is made of a metal such as aluminum or a resin, and has a diameter corresponding to the diameter of the workpiece 1. The upper surface side of this annular base is connected to the lower surface side of the mount 30. In other words, the grinding wheel 32 is attached to the spindle 28 via the mount 30.

[0035] A plurality of grinding wheels are fixed in an annular groove formed in the annular base in a circular arrangement. Specifically, each grinding wheel has its base end fixed in the annular groove, and the other portion is exposed from the annular groove. The grinding wheel includes abrasive grains and a binder that fixes the abrasive grains. The binder may also include other components (e.g., filler).

[0036] The bonding material is, for example, a vitrified bond whose main component is glass such as silicon dioxide (SiO2), a metal bond whose main component is metal such as copper (Cu), or a resin bond whose main component is resin such as phenolic resin. The abrasive grains are, for example, particles made of diamond or cBN (cubic boron nitride).

[0037] When processing (grinding) the workpiece 1 with the processing device (grinding device) 2, first, the workpiece 1 is placed on the holding surface 6a of the holding unit 6, and the holding unit 6 holds the workpiece 1 by suction. This exposes the back surface 1b, which is the surface to be processed, of the workpiece 1 upward. Next, the holding unit 6 is moved to the processing area 12 below the processing unit 14.

[0038] Thereafter, the spindle 28 is rotated to start rotation of the grinding wheel (processing tool) 32, and the processing unit 14 is lowered. Then, when the grinding wheel rotating along the circular orbit comes into contact with the back surface 1b of the workpiece 1, processing (grinding) of the workpiece 1 begins. Thereafter, when the thickness of the workpiece 1 reaches a predetermined finishing thickness, the lowering of the processing unit 14 is stopped, and processing (grinding) of the workpiece 1 is completed.

[0039] During grinding of the workpiece 1, powdery chips called machining chips are generated from the workpiece 1 and the grinding stone of the grinding wheel 32. In addition, heat called machining heat is generated due to friction between the workpiece 1 and the grinding stone. Therefore, in the processing device (grinding device) 2, a processing fluid is supplied to the processing unit 14 and the workpiece 1 when the workpiece 1 is processed. The processing device 2 is equipped with an inlet 34 through which the processing fluid flows in from the outside, and a supply path connecting the inlet 34 to a supply nozzle that supplies the processing fluid to the workpiece 1, etc.

[0040] The machining fluid is, for example, pure water or pure water mixed with an additive such as a surfactant. The machining fluid supplied to the workpiece 1 from a supply nozzle or the like cools the workpiece 1 and the machining unit 14, and also washes away machining debris generated during machining. The machining fluid that has absorbed the machining debris falls outside the holding unit 6 and is received in a drain equipped with a drain outlet, and is discharged from the drain outlet to the outside of the machining device 2.

[0041] The processing device 2 is provided with a discharge path 36 for discharging used processing fluid from the processing device 2. The used processing fluid is then discharged as waste fluid from the processing device 2 through the discharge path 36 and discharged into the circulation system 40. The waste fluid discharged from the processing device 2 to the circulation system 40 contains processing debris generated from the workpiece 1 and processing tools. For example, in a processing device 2 that processes a large number of silicon wafers, waste fluid containing a large amount of silicon microparticles as processing debris is discharged.

[0042] The circulation system 40 has the function of treating the waste liquid discharged from the processing device 2, producing a machining fluid from the waste liquid, and sending the machining fluid to the processing device 2. Next, the circulation system 40 will be described. FIG. 1 shows a conceptual diagram that schematically illustrates the circulation system 40. The circulation system 40 includes a machining debris removal section (machining debris removal unit) 42 that removes machining debris from the waste liquid, and a machining fluid generation section (machining fluid generation unit, pure water generation unit) 44 that generates a machining fluid from the waste liquid from which the machining debris has been removed.

[0043] Furthermore, the circulation system 40 has the processing device 2 and connection pipes connecting each unit. More specifically, the circulation system 40 includes a connection pipe 46a connecting the processing device 2 and the machining debris removal unit 42, a connection pipe 46b connecting the machining debris removal unit 42 and the machining fluid generation unit 44, and a connection pipe 46c connecting the machining fluid generation unit 44 and the processing device 2. The connection pipes 46a, 46b, and 46c form a circulation path for the machining fluid in the circulation system 40. The circulation system 40 may include connection pipes for connecting other units, etc. to the circulation path.

[0044] The circulation system 40 also includes pumps 48a, 48b, and 48c that send the machining fluid in the circulating direction through the connecting pipes 46a, 46b, and 46c, respectively. The machining fluid is sent in the circulating direction by operating the pumps 48a, 48b, and 48c. Each connecting pipe 46a, 46b, and 46c may also be provided with a tank (container, not shown) for temporarily storing the machining fluid.

[0045] 1 is mainly composed of the machining debris removal unit 42 and the machining fluid generation unit 44, but the circulation system 40 is not limited to this. For example, the circulation system 40 may be composed of a single processing device that combines the functions of the machining debris removal unit 42 and the machining fluid generation unit 44. Furthermore, the circulation system 40 may include a functional unit other than the machining debris removal unit 42 and the machining fluid generation unit 44.

[0046] The machining fluid generating unit 44 processes the waste fluid from which the machining debris has been removed to generate machining fluid that can be used in the machining device 2. The machining fluid generating unit 44 includes, for example, an ultraviolet irradiation unit that irradiates the waste fluid with ultraviolet rays, an ion exchange unit that exchanges ions contained in the waste fluid, and a filtration filter that filters the waste fluid.

[0047] Microorganisms may enter the waste liquid (used machining liquid) discharged from the machining device 2. The ultraviolet irradiation unit destroys microorganisms and the like that have entered the waste liquid. The ion exchange unit exchanges cations other than hydrogen ions contained in the waste liquid with hydrogen ions, and exchanges anions other than hydroxide ions contained in the waste liquid with hydroxide ions. The filtration filter removes fine particles contained in the waste liquid. In this way, the machining liquid generation unit 44 generates a machining liquid composed of pure water or the like.

[0048] The debris removal section 42 of the circulation system 40 has a function of removing debris from waste liquid containing the debris by electrophoresis. The circulation system 40 further includes a water acquisition unit 50 that acquires water from the debris removed from the waste liquid by the debris removal section 42. The water acquisition unit 50 is provided in the circulation system 40 either integrally with the debris removal section 42 or adjacent to the debris removal section 42.

[0049] Next, the processing debris removal section 42 and the water acquisition unit 50 according to this embodiment will be described. Fig. 2 is a cross-sectional view showing a schematic view of the processing debris removal section 42 and the water acquisition unit 50. The processing debris removal section 42 includes a storage tank 52. The storage tank 52 stores waste liquid that flows into the processing debris removal section 42 through the connection pipe 46a.

[0050] One end of a liquid supply pipe 54 is connected to the storage tank 52, and the other end of the liquid supply pipe 54 is connected to a liquid tank 56. A liquid supply pump 58 is provided in the liquid supply pipe 54, and when the liquid supply pump 58 is operated, the waste liquid stored in the storage tank 52 is pumped up and sent to the liquid tank 56 through the liquid supply pipe 54.

[0051] In the liquid tank 56 of the machining debris removal unit 42, machining debris 7 is removed from the waste liquid 5 by electrophoresis. The liquid tank 56 is configured as a rectangular box with an open top, and is capable of storing the waste liquid 5 containing the machining debris 7. In the liquid tank 56, a plurality of first electrodes (anode plates) 60 and a plurality of second electrodes (cathode plates) 62 facing the first electrodes 60 are immersed in the waste liquid 5. Each of the first electrodes 60 is connected to the positive pole of a DC power supply (not shown), and each of the second electrodes 62 is connected to the negative pole of this DC power supply.

[0052] The first electrode (anode plate) 60 and the second electrode (cathode plate) 62 are formed in the shape of rectangular flat plates and are preferably made of an electrochemically noble material. For example, the first electrode 60 is preferably made of a material such as copper, silver, platinum, gold, or SUS. In the liquid tank 56, the adjacent first electrodes 60 and second electrodes 62 are spaced apart by a predetermined distance.

[0053] When a DC power supply electrically connected to the first electrode 60 and the second electrode 62 is activated, electrophoresis can be performed in the liquid tank 56 of the machining debris removal unit 42. When electrophoresis is performed, the negatively charged machining debris 7 in the waste liquid 5 is attracted to the first electrode 60, which functions as an anode, and the machining debris 7 adheres to the first electrode 60. This gradually removes the machining debris 7 from the waste liquid 5, and the waste liquid 5 is purified.

[0054] 2, it is preferable that a region 64 surrounded by a plurality of second electrodes (cathode plates) 62 is formed in the liquid tank 56. The second electrodes 62 are preferably formed, for example, to have a mesh structure. When electrophoresis is performed in the liquid tank 56, the second electrodes 62 are negatively charged, and therefore the machining debris 7, which is also negatively charged, does not approach the second electrodes 62. Therefore, the machining debris 7 does not pass through the mesh-structured second electrodes 62, while the waste liquid 5 passes through the second electrodes 62.

[0055] That is, the waste liquid 5 that enters the area 64 surrounded by the plurality of second electrodes (cathode plates) 62 does not contain the machining debris 7. Therefore, if a discharge pipe 66 is passed through this area 64, the waste liquid 5 from which the machining debris 7 has been removed can be discharged from the liquid tank 56 through the discharge pipe 66. The waste liquid 5 from which the machining debris 7 has been removed is sent from the discharge pipe 66 through the connection pipe 46b (see FIG. 1) to the machining liquid generation unit 44 described above.

[0056] As a result of the processing debris 7 being removed from the waste liquid 5 in the processing debris removal section 42, the processing debris 7 accumulates on the surface of the first electrode 60. Therefore, the first electrode 60 is periodically pulled out of the liquid tank 56, and the processing debris 7 is peeled off from the first electrode 60. Next, a configuration for peeling the processing debris 7 from the first electrode 60 will be described.

[0057] The chip removal section 42 includes a transport unit 68 that transports the first electrode 60 inside and outside the liquid tank 56. The transport unit 68 includes a guide rail 70 that extends from above the liquid tank 56 toward the outside of the liquid tank 56, a movable elevating shaft section 72 slidably connected to the guide rail 70, and a holder 74 connected to the movable elevating shaft section 72.

[0058] For example, the movable lifting shaft 72 is configured with an air cylinder, and can raise and lower the holding part 74 by expanding and contracting. However, the movable lifting shaft 72 may be configured with an elevating mechanism other than an air cylinder. The holding part 74 has an engaging pin (not shown) that engages with an engaged part 75 provided on the upper end of the first electrode (anode plate) 60. For example, the engaged part 75 of the first electrode 60 has an engaging hole into which the engaging pin of the holding part 74 is inserted. The holding part 74 can hold the first electrode 60 by inserting the engaging pin into the engaged part 75, and can release the holding of the first electrode 60 by removing the engaging pin from the engaged part 75.

[0059] When removing the first electrode 60 from the liquid tank 56, the transport unit 68 moves the movable elevating shaft 72 along the guide rail 70 so that the holding portion 74 is positioned above the engaged portion 75 of the first electrode 60 placed in the liquid tank 56. The transport unit 68 then operates the movable elevating shaft 72 to lower the holding portion 74 to a height where it can hold the engaged portion 75, and holds the first electrode 60 on the holding portion 74 by inserting an engaging pin into the engaged portion 75, for example. The transport unit 68 then operates the movable elevating shaft 72 to raise the holding portion 74, thereby lifting the first electrode 60 from the liquid tank 56, and moves the movable elevating shaft 72 out of the liquid tank 56. In this manner, the transport unit 68 removes the first electrode 60 from the liquid tank 56.

[0060] Conventionally, the machining debris 7 adhering to the first electrode 60 has been removed from the first electrode 60 outside the liquid tank 56 and then collected. The machining debris 7 adhering to the first electrode 60 contains a considerable amount of waste liquid 5. For this reason, the machining debris 7 removed from the first electrode 60 has sometimes been dried before being removed from the machining debris removal unit 42.

[0061] Regardless of whether the peeled-off machining debris 7 is dried or not, the waste liquid 5 in the liquid tank 56 is removed together with the machining debris 7, so the machining fluid circulating through the circulation system 40 gradually decreases. For this reason, in the past, the circulation system 40, which regenerates the waste liquid 5 discharged from the machining device 2 to generate machining fluid and sends the machining fluid to the machining device 2, had to be periodically replenished with machining fluid (water) from the outside.

[0062] One possible method for replenishing the machining fluid (water) to the circulation system 40 is to supply water from the factory equipment where the processing device 2 is located. However, this requires the preparation of supply pipes, pumps, etc., which not only incur costs but also consume limited space inside the factory, etc. If the amount of machining fluid (water) desired to be replenished to the circulation system 40 is small, an operator can periodically place the machining fluid (water) in a container and carry it to the circulation system, thereby eliminating the need to prepare a replenishing system near the processing device 2.

[0063] If the amount of machining fluid (water) that needs to be replenished is even smaller, a shortage of machining fluid (water) in the circulation system 40 can be prevented by simply replenishing the machining fluid (water) to the circulation system 40 at the timing of maintenance of the machining device 2, etc. In this case, there is no need for an operator to replenish the machining fluid (water) on a daily basis.

[0064] Therefore, the water acquisition unit 50 according to this embodiment is used together with the processing debris removal section 42. The water acquisition unit 50 according to this embodiment will be described below. The water acquisition unit 50 includes a water recovery section 76 that recovers water released from the processing debris 7 that has been removed from the waste liquid 5 by electrophoresis, and a return flow path 78 for mixing the water recovered in the water recovery section 76 with either or both of the waste liquid 5 from which the processing debris 7 has been removed and the waste liquid 5 before the processing debris 7 has been removed. Each part of the water acquisition unit 50 will be described in detail.

[0065] For example, the water recovery unit 76 includes a peeling unit 80 that peels off the chips 7 that have adhered to the electrode (first electrode 60) from the electrode (first electrode 60) by electrophoresis. The peeling unit 80 is provided at a position adjacent to the liquid tank 56. The peeling unit 80 includes a pair of peeling plates 82 that can move toward and away from each other.

[0066] The two stripping plates 82 are arranged parallel to the surface of the flat first electrode 60 and in a region along the horizontal direction so as to sandwich the first electrode 60 from both sides. This region sandwiched between the two stripping plates 82 in the stripping unit 80 is referred to as the narrowed region. By operating the moving / lifting shaft unit 72 to raise and lower the holding unit 74, the first electrode 60 can be moved up and down in the region sandwiched between the two stripping plates 82. The stripping unit 80 is equipped with a drive unit formed by an air cylinder or the like, and the drive unit moves the pair of stripping plates 82 so as to approach or move apart from each other.

[0067] When the peeling unit 80 peels off the chips 7 adhering to the first electrode 60 from the first electrode 60, the pair of stripping plates 82 of the peeling unit 80 are separated from each other, and the first electrode 60 is lowered from above between the pair of stripping plates 82. Then, the height of the upper end of the first electrode 60 is made to match the height of the narrowed region of the peeling unit 80, and the drive unit is operated to bring the pair of stripping plates 82 closer to each other, thereby sandwiching the first electrode 60 between the pair of stripping plates 82.

[0068] Thereafter, the first electrode 60 is pulled up. Then, the scraping plate 82 scrapes off the processing debris 7 adhering to the surface of the first electrode 60, causing the processing debris 7 to fall downward. The first electrode 60 from which the adhering processing debris 7 has been removed is returned to the liquid tank 56 and used again for electrophoresis.

[0069] The water recovery unit 76 may include a drying chamber 84 that dries, while transporting, the chips 7 that have been peeled off from the electrode (first electrode 60) by the peeling unit 80. The drying chamber 84 includes an inlet 86 that receives the chips 7 that have been peeled off from the first electrode 60 by the peeling unit 80 and dropped, and the chips 7 that have dropped from the first electrode 60 enter the drying chamber 84 from the inlet 86.

[0070] Inside the drying chamber 84, there are arranged a conveyor belt 90 that conveys the processing scraps 7, and a guide plate 92 that guides the processing scraps 7 that enter the drying chamber 84 from the inlet 86 to the starting end of the ring-shaped conveyor belt 90. The ring-shaped conveyor belt 90 is hung on a pair of rollers 94, and a rotational drive source such as a motor is connected to at least one of the rollers 94. When the rotational drive source is operated with the processing scraps 7 placed on the conveyor belt 90, the conveyor belt 90 rotates, and the processing scraps 7 placed on the conveyor belt 90 move.

[0071] A drying unit for drying the processing scraps 7 placed on the conveyor belt 90 is provided near the conveyor belt 90 inside the drying chamber 84. The drying unit includes a heating section 96, which is constituted by, for example, an electric heating wire or a heater, and heats the processing scraps 7. The heating section 96 is provided, for example, inside the ring-shaped conveyor belt 90. When the heating section 96 is operated while the processing scraps 7 are being conveyed by the conveyor belt 90, the processing scraps 7 are heated and their temperature rises, which promotes evaporation of the waste liquid 5 taken up by the processing scraps 7 and generates water vapor.

[0072] The heating unit 96 provided inside the drying chamber 84 is not limited to an electric heating wire or a heater. For example, an infrared lamp that irradiates infrared rays onto the processing scraps 7 transported by the conveyor belt 90 to heat the processing scraps 7 may be provided as a heating unit on the top plate of the drying chamber 84. Alternatively, a heat gun that blows hot air onto the processing scraps 7 transported by the conveyor belt 90 may be provided as a heating unit inside the drying chamber 84.

[0073] A drop port 98 is provided in the bottom plate of the drying chamber 84 on the terminal side of the conveyor belt 90. A collection container 100 is installed directly below the drop port 98 outside the drying chamber 84. The processing debris 7, which is heated and dried in the drying chamber 84 and conveyed to the terminal side of the conveyor belt 90, falls from the terminal end of the conveyor belt 90 and passes through the drop port 98, proceeding to the outside of the drying chamber 84. The processing debris 7 is then received and collected in the collection container 100. When a predetermined amount of processing debris 7 has accumulated in the collection container 100, the collection container 100 is removed and replaced with a new collection container 100.

[0074] An exhaust port 102 is provided on the top plate of the drying chamber 84 on the terminal end side of the conveyor belt 90. A fan 104 is provided in the exhaust port 102 to suck out gas inside the drying chamber 84 through the exhaust port 102. Air (fluid) containing water vapor generated from the processing waste 7 inside the drying chamber 84 is discharged to the outside of the drying chamber 84 through the exhaust port 102 by the action of the fan 104.

[0075] An openable and closable lid 88 is provided at the inlet 86 of the drying chamber 84. While the peeling unit 80 is removing the machining chips 7 from the first electrode 60, the lid 88 does not block the inlet 86 and does not prevent the falling machining chips 7 from entering the inlet 86. On the other hand, while the machining chips 7 are not being peeled from the first electrode 60, the inlet 86 is closed by the lid 88 to prevent dust and the like from entering the inlet 86.

[0076] In order to promote the discharge of fluid containing water vapor generated from the processing waste 7 from the exhaust port 102 even while the inlet 86 is closed by the lid 88, it is preferable that the lid 88 be provided with an intake hole. In this case, while the fan 104 is operating, air enters the drying chamber 84 through the intake hole, preventing a decrease in the air pressure inside the drying chamber 84, making it easier for the fan 104 to discharge the fluid inside the drying chamber 84.

[0077] An exhaust path 106 is connected to the exhaust port 102 of the drying chamber 84. The exhaust path 106 is connected to a separation section 108 provided in the water recovery section 76 of the water acquisition unit 50. The separation section 108 separates water from a fluid (gas) containing water vapor generated from the processing debris 7 peeled off from the electrode (first electrode 60) in the peeling section 80. A return flow path 78 is connected to the separation section 108, and the water separated from the fluid and recovered in the separation section 108 of the water recovery section 76 is returned to the circulation system 40 via the return flow path 78.

[0078] Next, the separation section 108 provided in the water recovery section 76 will be described in detail. The separation section 108 takes the form of a flow path through which a fluid (gas) containing water vapor generated from the processing scraps 7 passes, and the fluid is brought into contact with the inner wall of the flow path to cause the water to adhere to the inner wall. At this time, the fluid may be cooled in the separation section 108. Then, the fluid (gas) from which water has been separated through the separation section 108 is exhausted to the outside. An exhaust path 110 that communicates with the external environment or the like is connected to the separation section 108.

[0079] The separation unit 108 is realized by, for example, one or more of a centrifugal separator having a cyclone passage through which the fluid flows, a crank passage portion having a crank passage through which the fluid flows, and a mesh plate having a plurality of holes through which the fluid flows. Examples of the separation unit 108 will be described below.

[0080] Fig. 3 is a cross-sectional view schematically illustrating a separation unit 108a according to an example. The separation unit 108a shown in Fig. 3 includes a centrifugal separation unit 112 having a cyclone flow path 114. High-pressure gas is mixed into the fluid that reaches the separation unit 108a through the exhaust path 106. Fig. 3 also includes a cross-sectional view schematically illustrating a high-pressure gas injection nozzle 116.

[0081] A pump, a cylinder, or the like that serves as a supply source of high-pressure air (high-pressure gas) is connected to the injection nozzle 116. Alternatively, an exhaust system of an ejector used in the processing device 2 or the like may be connected to the injection nozzle 116 as a supply source of high-pressure air (high-pressure gas). When high-pressure air is injected from the injection nozzle 116, the fluid proceeding from the exhaust path 106 to the centrifugal separation section 112 can be accelerated. It is believed that the higher the fluid speed, the more momentum the fluid has, and when the fluid collides with the wall surface of the cyclone flow path 114, which will be described next, the more likely water vapor contained in the fluid will liquefy.

[0082] The centrifugal separation section 112 includes a cylindrical outer tube 118 through which a fluid (gas) containing water vapor generated from the processing chips 7 flows, and a cylindrical inner tube 120 housed inside the outer tube 118. The inner tube 120 is disposed inside the outer tube 118 so that the distance between the inner wall of the outer tube 118 and the outer wall of the inner tube 120 is approximately constant around the entire circumference.

[0083] The upper end of the outer pipe 118 is closed by a disc-shaped top plate 122, and the lower end of the outer pipe 118 is closed by a disc-shaped bottom plate 124. A drain port 126 is formed in the center of the bottom plate 124, and the drain port 126 is connected to the return flow path 78. An inlet port 128 is formed in the side wall near the upper end of the outer pipe 118, and the exhaust path 106 is connected to this inlet port 128.

[0084] The upper end of the inner tube 120 is closed by a top plate 130, while the lower end 132 of the inner tube 120 is open. The lower end 132 of the inner tube 120 is not in contact with the bottom plate 124 that closes the lower end of the outer tube 118, but is separated a predetermined distance from the bottom plate 124. An exhaust path 110 is connected to the upper end of the inner tube 120, and the exhaust path 110 passes through the outer tube 118 and leads to the outside of the centrifugal separation section 112.

[0085] In the separation section 108a, the fluid (gas) containing water vapor generated from the machining chips 7 is accelerated by the high-pressure gas injected from the injection nozzle 116 and flows into the outer tube 118 of the centrifugal separation section 112 from the inlet 128. At this time, the fluid advances downward inside the outer tube 118 while swirling along the outer peripheral surface of the inner tube 120. Therefore, the space between the outer tube 118 and the inner tube 120 becomes the cyclone flow path 114.

[0086] The angle at which the exhaust path 106 is connected to the outer pipe 118 should be determined so that the fluid can smoothly swirl and move inside the outer pipe 118. That is, the exhaust path 106 should be connected to the outer pipe 118 at an angle that does not point toward the central axis of the cylindrical outer pipe 118, and preferably does not follow the radial direction of the outer pipe 118. In particular, it is preferable that the exhaust path 106 is connected to the outer pipe 118 in a direction that follows the inner circumferential surface of the outer pipe 118 near the inlet 128.

[0087] As the fluid flows in a vortex pattern in the cyclone flow path 114, it comes into contact with the inner surface of the outer pipe 118 and the outer surface of the inner pipe 120 and is cooled, and the water vapor contained in the fluid liquefies, adhering to the inner surface of the outer pipe 118 and the outer surface of the inner pipe 120. The water produced by the liquefaction of the water vapor flows downward along the wall surface. The water then collects on the bottom plate 124 and flows from the drain outlet 126 into the return flow path 78.

[0088] Meanwhile, the fluid (gas) from which water has been desorbed while flowing through the cyclone flow path 114 advances from the lower end 132 of the inner pipe 120 into the interior of the inner pipe 120, rises inside the inner pipe 120, and advances to the exhaust path 110 connected to the inner pipe 120. Then, this fluid is discharged through the exhaust path 110 into the space outside the separation section 108a.

[0089] In this way, the separation section 108a can separate water and the fluid (gas) in the cyclone channel 114. That is, the water acquisition unit 50 can acquire water from the processing debris 7 removed from the waste liquid 5 containing the processing debris 7 in the processing debris removal section 42.

[0090] Fig. 4 is a cross-sectional view schematically illustrating another example of a separation unit 108b. The separation unit 108b shown in Fig. 4 has a crank channel portion 134 having a crank channel 136. As with the separation unit 108a described in Fig. 3, in order to increase the flow rate of the fluid that reaches the separation unit 108b through the exhaust channel 106, high-pressure gas supplied from the injection nozzle 116 is mixed into the fluid.

[0091] The crank flow passage portion 134 has a box-like shape, and the crank flow passage 136 is formed inside the crank flow passage portion 134. A plurality of barrier walls 138 protruding from the inner wall are provided inside the crank flow passage portion 134. The barrier walls 138 are arranged so as to form the crank flow passage 136 that includes a number of bends.

[0092] A drain port 142 is formed in the bottom plate 140 of the crank channel section 134, an inlet port 146 is formed in one side wall 148 of the crank channel section 134, and an exhaust port 150 is formed in the other side wall 148 of the crank channel section 134. The exhaust passage 106 is connected to the inlet port 146, the return passage 78 is connected to the drain port 142, and the exhaust passage 110 is connected to the exhaust port 150.

[0093] The fluid (gas) containing water vapor generated from the machining chips 7 is accelerated by the high-pressure gas supplied from the injection nozzle 116, flows into the crank flow passage 134 from the inlet 146, and travels through the crank flow passage 136 while coming into contact with the inner wall and the barrier 138. The fluid is then cooled, and the water vapor contained in the fluid liquefies, adhering to the inner wall and the barrier 138 of the crank flow passage 134. The water generated by the liquefaction of the water vapor travels downward along the wall surface. The water then collects on the bottom plate 140 and travels through the drain outlet 142 to the return flow passage 78.

[0094] On the other hand, the fluid (gas) from which water has escaped while flowing through the crank flow path 136 proceeds from the exhaust port 150 to the exhaust path 110. This fluid is then released into the space outside the separation unit 108b through the exhaust path 110. In this way, the separation unit 108b can separate the water and the fluid (gas) in the crank flow path 136.

[0095] Fig. 5 is a cross-sectional view schematically illustrating a separation unit 108c according to yet another example. The separation unit 108c shown in Fig. 5 has a mesh plate 154 having a plurality of holes 156 through which the fluid flows. The mesh plate 154 is installed inside a box-shaped housing 152 of the separation unit 108c so as to block the flow of the fluid. As with the separation units 108a and 108b described in Figs. 3 and 4, in order to increase the flow rate of the fluid that reaches the separation unit 108c through the exhaust path 106, high-pressure gas supplied from the injection nozzle 116 is mixed into the fluid.

[0096] A drain port 160 is formed in the bottom plate 158 of the housing 152 of the separation section 108c, an inlet 164 is formed in one side wall 166 of the housing 152, and an exhaust port 168 is formed in the other side wall 166 of the housing 152. The exhaust path 106 is connected to the inlet 164, the return flow path 78 is connected to the drain port 160, and the exhaust path 110 is connected to the exhaust port 168.

[0097] The fluid (gas) containing water vapor generated from the processing waste 7 flows into the housing 152 from the inlet 164 and progresses through the inside of the housing 152 while passing through the holes 156 in the mesh plate 154. During this process, the fluid is cooled, and the water vapor contained in the fluid liquefies, and the water adheres to the inner wall of the housing 152 and the mesh plate 154. The water produced when the water vapor liquefies progresses downward along the mesh plate 154 and the wall surface. The water then collects on the bottom plate 158 and progresses from the drain outlet 160 to the return flow path 78.

[0098] On the other hand, the fluid (gas) from which the water has escaped while flowing through the housing 152 is discharged from the exhaust port 168 through the exhaust path 110 to the space outside the separation unit 108c. In this way, the separation unit 108c can separate the water and the fluid (gas). That is, the water acquisition unit 50 can acquire water from the processing debris 7 removed from the waste liquid 5 containing the processing debris 7 in the processing debris removal unit 42.

[0099] Up to this point, we have described exemplary configurations of the separation section 108 included in the water recovery section 76 of the water acquisition unit 50, but the configuration of the separation section 108 is not limited to these. Furthermore, the separation section 108 may be configured by a combination of two or more of: a centrifugal separation section 112 having a cyclone channel 114 through which the fluid flows, a crank channel section 134 having a crank channel 136 through which the fluid flows, and a mesh plate 154 having a plurality of holes 156 through which the fluid flows.

[0100] The water recovery unit 76 may further include a cooling unit that cools the fluid. The cooling unit cools the fluid (gas) containing water vapor generated from the processing debris 7 as it travels through the flow path of the separation unit 108, thereby lowering the temperature of the fluid. For example, the cooling unit may be a Peltier element or the like attached to a housing that constitutes the separation unit 108, and indirectly lowers the temperature of the fluid by lowering the temperature of the housing. Lowering the temperature of the fluid makes it easier for the water vapor contained in the fluid to liquefy and generate water, and also reduces the amount of water vapor remaining in the fluid (gas).

[0101] The water separated and recovered from the fluid (gas) containing water vapor generated from the machining debris 7 by the separation section 108 of the water recovery section 76 of the water acquisition unit 50 flows into the return flow path 78. This return flow path 78 is connected to, for example, the storage tank 52 of the machining debris removal section (machining debris removal unit) 42.

[0102] For example, as shown in Fig. 1, the return flow path 78 merges with the connecting pipe 46a, and the water flowing through the return flow path 78 reaches the storage tank 52 through the connecting pipe 46a. Alternatively, as shown in Fig. 2, the return flow path 78 is directly connected to the storage tank 52, and the water flowing through the return flow path 78 reaches the storage tank 52. In either case, the water recovered from the processing debris 7 by the water recovery unit 76 is mixed with the waste liquid 5 from which the processing debris 7 has not been removed, and is returned to the circulation path of the circulation system 40.

[0103] It should be noted that a carbon dioxide supply source that supplies carbon dioxide may be connected to the storage tank 52. The carbon dioxide supply source supplies carbon dioxide gas or carbonated water to the waste liquid stored in the storage tank 52. The carbon dioxide supplied from the carbon dioxide supply source is mixed with the waste liquid stored in the storage tank 52, thereby controlling the hydrogen ion exponent (pH) of the waste liquid.

[0104] The waste liquid 5 stored in the storage tank 52 is sent to the liquid tank 56 for electrophoresis. In order to efficiently perform electrophoresis in the liquid tank 56, it is preferable that the pH of the waste liquid 5 is adjusted in advance to a predetermined value. The pH of the waste liquid 5 can be adjusted by supplying carbon dioxide gas or the like to the waste liquid 5 in the storage tank 52.

[0105] If the water recovered by the water recovery section 76 of the water acquisition unit 50 is haphazardly supplied to the storage tank 52 through the return flow path 78, the pH value of the waste liquid 5 inside the storage tank 52 will fluctuate. Therefore, the water acquisition unit 50 may further include an on-off valve 170 (see FIG. 2 ) in the return flow path 78. The on-off valve 170 opens and closes while controlling the pH value of the waste liquid 5 inside the storage tank 52 to prevent it from becoming a value unsuitable for electrophoresis, and sends water to the storage tank 52 through the return flow path 78.

[0106] Furthermore, if the pH of the waste liquid 5 stored in the storage tank 52 is lower than an appropriate value, the pH of the waste liquid 5 may be adjusted by opening the on-off valve 170 and sending water to the storage tank 52. This makes it possible to increase the pH value of the waste liquid 5 stored in the storage tank 52. In other words, the on-off valve 170 can also function as a pH adjuster for the waste liquid 5 stored in the storage tank 52. In this case, the storage tank 52 does not need to be provided with a dedicated adjuster for adjusting the pH of the waste liquid 5.

[0107] Furthermore, exhaust path 110 connected to separation unit 108 may be connected to a suction source provided in a factory or the like where processing device 2 is installed. When the suction source is connected to separation unit 108 through exhaust path 110, the fluid (gas) flows smoothly through separation unit 108, facilitating separation of water from the fluid. However, in this case, the negative pressure supplied to separation unit 108 may leak into return flow path 78, causing a decrease in the negative pressure in separation unit 108 or causing a backflow of water in return flow path 78.

[0108] If the open / close valve 170 is provided in the return flow path 78, it is possible to prevent backflow in the return flow path 78 and suppress a decrease in negative pressure in the separation section 108. The open / close valve 170 may be replaced with a check valve.

[0109] The return flow path 78 does not need to be connected to the storage tank 52, and the water flowing through the return flow path 78 does not need to be mixed with the waste liquid 5 from which the machining debris 7 has not been removed. For example, the return flow path 78 may be connected to and merge with the discharge pipe 66 or the connection pipe 46b through which the waste liquid 5 from which the machining debris 7 has been removed flows in the machining debris removal section 42. The water flowing through the return flow path 78 may be mixed with the waste liquid 5 from which the machining debris has been removed. In this case, the water that has flowed through the return flow path 78 proceeds to the machining fluid generation section (machining fluid generation unit) 44 together with the waste liquid 5 from which the machining debris has been removed.

[0110] As described above, the water acquisition unit 50 according to this embodiment and the circulation system 40 incorporating this water acquisition unit 50 acquire water from processing debris 7 removed from the waste liquid 5 containing the processing debris 7. That is, the water acquisition unit 50 includes a water recovery section 76 that recovers water released from the processing debris 7 removed from the waste liquid 5 by electrophoresis, and a return flow path 78 for mixing the water recovered in the water recovery section 76 with either or both of the waste liquid 5 from which the processing debris 7 has been removed and the waste liquid 5 before the processing debris 7 was removed.

[0111] Therefore, when the processing debris 7 is removed from the waste liquid 5, the water removed together with the processing debris 7 is recovered from the processing debris 7 and returned to the waste liquid 5. That is, in the circulation system 40 that regenerates the waste liquid 5 discharged from the processing device 2 and supplies it to the processing device 2 as a processing liquid, less water is lost as the processing debris 7 is removed from the waste liquid 5. In this case, the amount of water that needs to be replenished to the circulation system 40 can be reduced, so that the amount can be handled by the replenishment work by workers, and there is no need to prepare a dedicated water replenishment device and connect it to the circulation system 40 in the factory where the processing device 2 is installed.

[0112] Furthermore, if the amount of water to be replenished to the circulation system 40 can be sufficiently reduced, it may be possible to prevent a water shortage in the circulation system 40 simply by replenishing water to the circulation system 40 at the timing of maintenance of the processing device 2. In this case, there will be no need for workers to replenish water on a daily basis.

[0113] In the above embodiment, the case where the water recovery section 76 of the water acquisition unit 50 recovers water by liquefying water vapor generated from the processing debris 7 removed from the waste liquid 5 by the processing debris removal section 42 has been described. That is, the case where the separation section 108 separates water from a fluid containing water vapor generated from the processing debris 7 has been described.

[0114] However, the water acquisition unit 50 according to one embodiment of the present invention and the circulation system 40 incorporating the water acquisition unit 50 are not limited to this. That is, the water acquisition unit 50 may acquire water from a fluid (gas) other than the fluid containing water vapor generated from the processing waste 7.

[0115] For example, in the liquid tank 56 where electrophoresis is performed in the processing debris removal unit 42, the stored waste liquid 5 gradually evaporates. Furthermore, when the first electrode 60 is pulled out of the liquid tank 56, the waste liquid 5 adhering to the surface of the first electrode 60 gradually evaporates. Therefore, the air inside the processing debris removal unit 42 may flow into the separation unit 108 of the water recovery unit 76 together with the fluid containing water vapor generated from the processing debris 7. In this case, the water that has evaporated directly from the waste liquid 5 into the air can also be recovered by the water recovery unit 76, further reducing the loss of water circulating through the circulation system 40.

[0116] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention. [Explanation of symbols]

[0117] 1 Workpiece 1b back side 3 Protective tape 5. Waste liquid 7 Processing waste 2 Processing equipment 4 Foundation 6 Holding Unit 6a Holding surface 8 X-axis moving table 10 Loading / unloading area 12 Processing area 14 Processing unit 16 Support part 18 Z-axis guide rail 20 Z-axis moving plate 22 Z-axis ball screw 24 Z-axis pulse motor 26 Spindle housing 28 Spindle 30 Mount 32 Grinding Wheel 34 Inlet 36 Exhaust channel 40 Circulation System 42 Processing waste removal section 44 Processing fluid generation section 46a, 46b, 46c Connection piping 48a, 48b, 48c Pumps 50 Water Acquisition Units 52 Storage Tank 54 Liquid delivery piping 56 Liquid tank 58 Liquid transfer pump 60 1st electrode 62 2nd electrode 64 areas 66 Discharge pipe 68 Transport Unit 70 Guide Rail 72 Moving lifting axis 74 Holding part 75 Engaged part 76 Water recovery section 78 Return channel 80 Peeling part 82 Stripping board 84 Drying room 86 Inlet 88 Lid 90 conveyor belt 92 Signboard 94 Roller 96 Heating section 98 Drop Hole 100 Collection container 102 Exhaust port 104 Fan 106 Exhaust duct 108,108a,108b,108c Separation part 110 Exhaust duct 112 Centrifugal separation section 114 Cyclone flow path 116 Injection Nozzle 118 Outer tube 120 Inner tube 122,130 Top plate 124,140,158 Bottom plate 126,142,160 Drain 128,146,164 Inlet 132 Bottom end 134 Crank flow passage 136 Crank flow passage 138 Barrier 144,148,162,166 side wall 150,168 exhaust port 152 cabinet 154 mesh plate 156 holes 170 Opening and closing valve

Claims

1. A water acquisition unit for acquiring water from processing wastes removed from a waste liquid containing the processing wastes, a water recovery unit that recovers water released from the processing waste that has been removed from the waste liquid by electrophoresis; A water acquisition unit having a return flow path for mixing the water recovered in the water recovery section with either or both of the waste liquid from which the processing debris has been removed and the waste liquid before the processing debris has been removed.

2. The water acquisition unit according to claim 1 , further comprising an on-off valve provided in the return flow path.

3. The water recovery unit includes a peeling unit that peels off the processing debris that has adhered to the electrode by the electrophoresis from the electrode; The water acquisition unit according to claim 1 , further comprising a separation section that separates the water from a fluid containing water vapor generated from the processing debris peeled off from the electrode by the peeling section.

4. The water acquisition unit of claim 3, wherein the separation section comprises one or more of a centrifugal separation section having a cyclone flow path through which the fluid flows, a crank flow path section having a crank flow path through which the fluid flows, and a mesh plate having a plurality of holes through which the fluid flows.

5. The water acquisition unit according to claim 3 , wherein the water recovery section further comprises a heating section that heats the processing waste peeled off from the electrode by the peeling section.

6. 4. A water acquisition unit according to claim 3, wherein the water recovery section further comprises a cooling section for cooling the fluid.

7. A circulation system that processes waste liquid containing processing waste discharged from a processing device that processes a workpiece, produces processing liquid from the waste liquid, and sends the processing liquid to the processing device, a processing debris removal unit that removes the processing debris from the waste liquid by electrophoresis; a water acquisition unit according to any one of claims 1 to 6, which acquires water from the processing debris removed by the processing debris removal section; a machining fluid generating section that generates a machining fluid from the waste liquid from which the machining debris has been removed by the machining debris removing section and water recovered by the water recovering section of the water acquiring unit, a circulation system that supplies the machining fluid generated in the machining fluid generation unit to the machining device;

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