Pure water recycling apparatus

Abstract

To provide a pure water recycling apparatus capable of removing ions from concentrated water discharged from electric regeneration type ion exchange means to reproduce pure water and making pure water replenishment unnecessary.SOLUTION: A pure water recycling apparatus 1 comprises: a tank 10 for storing machining waste water discharged from a grinding device (grinder) 100 that receives supplied pure water to machine a workpiece; a machining chip removal filter 20 that removes machining chips from the machining waste water supplied from the tank 10 to generate fresh water; an ultraviolet ray irradiation unit 30 that irradiates the fresh water with an ultraviolet ray; and an electrodeionization exchange unit 40 that removes organic ions contained in the fresh water through electrodialysis to generate pure water. A distilled water generation unit 50 is provided to evaporate the concentrated water discharged from the electrodeionization exchange unit 40 to generate distilled water. The distilled water is returned together with the pure water to the grinding device 100.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a pure water recycling apparatus for regenerating processing wastewater discharged from a processing device into pure water and reusing the same. [Background technology]

[0002] For example, in the manufacturing process of semiconductor devices such as ICs and LSIs used in various electronic devices, the back surface of the wafer is ground by a grinding wheel to thin the wafer to a predetermined thickness in order to reduce the size and weight of the semiconductor device. In this grinding machine, pure water is supplied as a processing liquid to the contact point (processing point) between the grinding wheel and the wafer to remove frictional heat generated at the contact point (processing point) and cool the contact point, and to wash away grinding debris generated by grinding. In the grinding machine, pure water is also used as a cleaning liquid for cleaning the ground wafer by a cleaning unit.

[0003] Therefore, the grinding machine discharges a processing waste liquid containing grinding chips, organic ions, etc., and if this processing waste liquid is directly disposed of, there is a problem that it pollutes the environment and increases the consumption of pure water, resulting in a rise in processing costs. For this reason, processing waste liquid treatment devices (pure water recycling devices) for regenerating processing waste liquid discharged from processing devices such as grinding machines into pure water and reusing it have been proposed in, for example, Patent Documents 1 to 3.

[0004] That is, Patent Document 1 proposes a configuration in which various components such as a waste liquid storage tank, a waste liquid filtration means, a clean water storage tank, a pure water generating means, a pure water temperature adjustment means, and a control means are compactly housed in an apparatus housing, thereby making the entire apparatus compact.

[0005] Moreover, Patent Document 3 proposes a processing waste liquid treatment device that employs a configuration in which a backwash filter that filters processing waste liquid is backwashed with cleaning water and processing debris accumulated in the backwash filter is removed, thereby enabling the backwash filter to be easily replaced in a short time.

[0006] Furthermore, Patent Document 3 proposes a processing waste liquid treatment device that can regenerate ion exchange resin without stopping the operation of the processing equipment. Specifically, this processing waste liquid treatment device removes ions from processing waste liquid using ion exchange resin of an electrically regenerated ion exchange means to produce pure water, and regenerates the ion exchange resin by electrodialysis. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2009-190128 A [Patent Document 2] Patent Publication No. 2022-180005 [Patent Document 3] Patent Publication No. 2021-030362 Summary of the Invention [Problem to be solved by the invention]

[0008] In the processing wastewater treatment devices proposed in Patent Documents 1 and 2, the ion exchange capacity of the ion exchange resin provided in the pure water generating means gradually decreases over time, causing a decrease in the purity of the generated pure water, so the ion exchange resin needs to be replaced periodically. In contrast, in the processing wastewater treatment device proposed in Patent Document 3, the ion exchange resin can be regenerated even while the processing device is in operation, so there is no need to replace the ion exchange resin.

[0009] In the electrical regeneration ion exchange means provided in the processing wastewater treatment device, ions removed from the processing wastewater flowing through the desalting compartment are released into the concentration compartment, and concentrated water in which the ions are concentrated is produced in the concentration compartment. For example, when pure water is regenerated at a rate of 30 mL / min, concentrated water is produced at a rate of 1 mL / min, and this small amount of concentrated water may be discarded as it is. In this case, it is necessary to replenish pure water by the amount of the discarded concentrated water, which is uneconomical.

[0010] The present invention has been made in consideration of the above problems, and its object is to provide a pure water recycling device that removes ions from concentrated water discharged from an electrically regenerated ion exchange means to regenerate pure water, and eliminates the need for refilling the pure water. [Means for solving the problem]

[0011] In order to achieve the above-mentioned object, the present invention provides a pure water recycling device that regenerates the pure water from the processing wastewater discharged from the processing device, the pure water recycling device comprising: a tank for storing processing wastewater discharged from a processing device that processes workpieces while receiving a supply of pure water; a processing debris removal filter that removes processing debris from the processing wastewater supplied from the tank to generate clean water; an ultraviolet irradiation unit that irradiates ultraviolet rays to the clean water; and an electrodeionization exchange unit that removes organic ions contained in the clean water by electrodialysis to generate pure water, the pure water recycling device being characterized in that it further comprises a distilled water generation unit that evaporates concentrated water discharged from the electrodeionization exchange unit to generate distilled water, and the distilled water is returned to the processing device together with the pure water. Effect of the Invention

[0012] According to the present invention, the concentrated water discharged from the electrodeionization exchange unit is evaporated in the distilled water generating unit to generate distilled water (pure water), so that the concentrated water is returned to the processing equipment without being discarded, and the distilled water can be reused as pure water. This eliminates the need to replenish pure water, and improves the economic effect. [Brief description of the drawings]

[0013] [Figure 1] 1 is a perspective view showing a configuration of a pure water recycling device according to the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing the internal structure of an electrodeionization exchange unit of the pure water recycling apparatus according to the present invention and the flows of various types of water (pure water, processing wastewater, clean water, electrolyzed water, concentrated water, and distilled water). [Diagram 3] 1 is a side cross-sectional view of a distilled water production unit of a pure water recycling apparatus according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0015] First, the configuration of a pure water recycling apparatus 1 according to the present invention will be described below with reference to FIGS.

[0016] [Configuration of pure water recycling equipment] The pure water recycling apparatus 1 according to the present invention is an apparatus for, for example, regenerating wastewater discharged from a grinding apparatus 100 that grinds a disk-shaped wafer (not shown) as a workpiece into pure water and reusing the pure water for grinding the wafer in the grinding apparatus 100, and includes the following components: That is, the pure water recycling apparatus 1 includes, as main components, a tank 10 for storing wastewater discharged from the grinding apparatus 100, a processing debris removal filter 20 for removing grinding debris (processing debris) from the processing wastewater supplied from the tank 10 to generate pure water, an ultraviolet irradiation unit 30 for irradiating ultraviolet rays onto the pure water, an electrodeionization exchange unit 40 for removing organic ions contained in the pure water by electrodialysis to generate pure water, a distilled water generating unit 50 for evaporating concentrated water discharged from the electrodeionization exchange unit 40 to generate distilled water, and a temperature adjustment unit 60 for adjusting the temperature of a mixture (pure water) of the distilled water generated by the distilled water generating unit 50 and the pure water generated by the electrodeionization exchange unit 40.

[0017] Here, the details of the configuration of the grinding apparatus 100 are not shown, but the grinding apparatus 100 is an apparatus that grinds a wafer, which is a workpiece, with a plurality of grinding stones attached in an annular shape to a grinding wheel that rotates at high speed, and during grinding, pure water, which is a processing liquid, is supplied to the contact point (processing point) between the grinding stone and the wafer. The grinding apparatus 100 is also provided with a cleaning unit for cleaning the ground wafer, and the cleaning of the wafer in this cleaning unit is performed by spraying pure water from a cleaning nozzle toward the wafer while the wafer is held on a spinner table and rotated at high speed.

[0018] Next, the main components of the pure water recycling apparatus 1 according to the present invention, namely the tank 10, the processing debris removal filter 20, the ultraviolet irradiation unit 30, the electrodeionization exchange unit 40, the distilled water production unit 50 and the temperature adjustment unit 60, will be described.

[0019] (tank) The tank 10 is a sealed rectangular container-like member for storing the processing wastewater discharged from the grinding device 100, and a pipe 2 extending from the side of the grinding device 100 is connected to the side of the tank 10. A pump P is installed on the top of the tank 10, and a pipe 3 extending from the discharge side of the pump P is connected to the top of the processing debris removal filter 20.

[0020] (machining debris removal filter) The machining debris removing filter 20 removes grinding debris from the machining wastewater supplied from the tank 10 through the piping 3 by the pump P to generate clean water, and is configured by accommodating a cylindrical filter (not shown) in a sealed cylindrical case 21. The piping 4 extending from the lower center of the machining debris removing filter 20 is connected to the upper center of the ultraviolet irradiation unit 30. The filter used for the machining debris removing filter 20 is, for example, a CC filter (product name) manufactured by Disco Corporation, but a plurality of such filters may be provided. Also, a reverse osmosis membrane (RO membrane) may be used as the filter.

[0021] (Ultraviolet irradiation unit) The ultraviolet irradiation unit 30 irradiates ultraviolet (UV) rays to the clean water from which grinding debris has been removed by the machining debris removing filter 20, and is equipped with a plurality of UV lamps (low-pressure mercury lamps, not shown). That is, in this ultraviolet irradiation unit 30, the clean water supplied from the machining debris removing filter 20 via a pipe 4 is irradiated with ultraviolet rays from the plurality of UV lamps, thereby sterilizing the clean water. A pipe 5 extending from the side of this ultraviolet irradiation unit 30 is connected to the upper part of the electric deionization exchange unit 40.

[0022] (Electrodeionization exchange unit) The electrodeionization exchange unit 40 generates pure water by removing organic ions contained in the fresh water supplied from the ultraviolet irradiation unit 30 through the pipe 5 by electrodialysis, and the inside of the sealed rectangular case 41 (see Fig. 1) is configured as shown in Fig. 2. That is, as shown in Fig. 2, inside the electrodeionization exchange unit 40, a titanium anode plate 42 and a stainless steel cathode plate 43 are arranged parallel to each other on both sides in the width direction (on the left and right sides in Fig. 2), and a 300 V DC power supply 44 is electrically connected to each of the anode plate 42 and the cathode plate 43.

[0023] In the space between the anode plate 42 and the cathode plate 43, a plurality of (three of each in the illustrated example) cation exchange membranes (cation membranes) 45a, 45b, 45c and anion exchange membranes (anion membranes) 46a, 46b, 46c are arranged in parallel and alternately. Inside the electric deionization exchange unit 40, two deionization compartments S1 are formed, each of which is defined by two adjacent cation exchange membranes 45b and 46a, and a cation exchange membrane 45c and 46b, and each of these deionization compartments S1 is filled with an ion exchange resin (a mixture of cation exchange resin and anion exchange resin) 47. The cation exchange membranes 45a, 45b, 45c are each capable of absorbing cations e + allows the passage of anions e -The anion exchange membranes 46a, 46b, and 46c function to prevent the passage of anions e - allows the passage of cations e + It serves the function of preventing the passage of

[0024] Narrow concentration chambers S2 are formed between the two adjacent cation exchange membranes 45a and 46a, between the cation exchange membranes 45b and 46b, and between the cation exchange membranes 45c and 46c. Furthermore, electrolysis chambers S3 are formed on both sides of the width of the electrodeionization unit 40, between the anode plate 42 and the adjacent cation exchange membrane 45a, and between the cathode plate 43 and the adjacent anion exchange membrane 46c.

[0025] A pipe 5 extending from the ultraviolet irradiation unit 30 is connected to each upper end of each deionization chamber S1 formed in the electrodeionization exchange unit 40. A pipe 6 extending from each deionization chamber S1 is connected to a temperature adjustment unit 60, a pipe 7 extending from each concentration chamber S2 is connected to a distilled water production unit 50, and a pipe 8 extending from each electrolysis chamber S3 is connected to a tank 10 (see FIG. 1).

[0026] (Distilled water generation unit) The distilled water generating unit 50 evaporates concentrated water supplied from the concentration chamber S2 of the electric deionization exchange unit 40 through the pipe 7 to generate distilled water (pure water), and is configured as shown in FIG. 3. That is, as shown in FIG. 3, the distilled water generating unit 50 includes a rectangular box-shaped container 51, and a vaporization chamber S is formed in the container 51. The vaporization chamber S contains a tray 53 supported on the bottom wall of the container 51 by a stand 52, a cylindrical suction member 54 whose lower end is received by the tray 53, and a circulator (fan) F that turbulently circulates the gas (air) in the vaporization chamber S. In this embodiment, the suction member 54 is configured of a cylindrical nonwoven fabric filter, but the suction member 54 can be made of any material (e.g., paper, resin sponge, porous metal, etc.) and shape other than nonwoven fabric as long as it can suck up condensed water by capillary action.

[0027] An outlet 51a for discharging gas (hot air) from the vaporization chamber S is opened at the center of the top wall of the container 51 in which the vaporization chamber is formed, and an inlet 51b for introducing gas (hot air) into the vaporization chamber S is opened at a location offset from the center of the bottom wall of the container 51. A blower B is disposed at the portion of the top of the container 51 where the outlet 51a opens. The blower B is driven to rotate by an electric motor (not shown). A pipe 7 extending from the concentration chamber S2 (see FIG. 2) of the electric deionization exchange unit 40 faces the inside of the vaporization chamber S, and an end of the pipe 7 opens above the tray 53.

[0028] Meanwhile, from the discharge side of blower B arranged on the upper part of container 51, duct 55 as a return pipe extends upward, is bent at a right angle and extends horizontally, and the extending end is bent at a right angle and extends vertically downward. The lower end of the part of duct 55 extending vertically downward is bent at a right angle and extends horizontally below container 51.

[0029] Here, a case 56 is attached in a tight contact state to the underside of the container 51, and a heating section 57A and a cooling section 57B stacked vertically are housed in the case 56, and an end of the duct 55 is connected to the cooling section 57B. Here, in this embodiment, the heating section 57A and the cooling section 57B are composed of Peltier elements 57, which are semiconductor thermoelectric elements, and the heating section 57A is composed of aluminum fins erected on the heating side of the Peltier element 57, and the cooling section 57B is composed of a plurality of aluminum fins erected on the cooling side of the Peltier element 57. Note that when a direct current is applied to the Peltier element 57 from a direct current power source (not shown), the heating section 57A generates heat due to the Peltier effect, and the cooling section 57B is cooled by absorbing heat.

[0030] Incidentally, an inlet 51b formed at the bottom of the container 51 opens into the case 56, and a distilled water acquisition section 58 in the form of a space partitioned by a heating section 57A and a cooling section 57B is formed at the end (the left end in FIG. 3) of the case 56. A nozzle 56a extends vertically downward from the distilled water acquisition section 58, and the nozzle 56a is connected to a temperature adjustment unit 60 via a pipe 9 and a pipe 6 shown in FIG. 1 and FIG. 2.

[0031] (Temperature control unit) The temperature adjustment unit 60 adjusts the temperature of the mixed water (pure water) of the distilled water produced by the distilled water production unit 50 and the pure water produced by the electrodeionization exchange unit 40, and includes a heating means and a cooling means (not shown). As shown in FIG. 1, a pipe 6 extending from the desalting chamber S1 (see FIG. 2) of the electrodeionization exchange unit 40 is connected to the side of the temperature adjustment unit 60, and a pipe 9 extending from the distilled water production unit 50 is connected to the pipe 6. Therefore, the mixed water (pure water) of the pure water produced in the electrodeionization exchange unit 40 and the distilled water produced by the distilled water production unit 50 is supplied to the temperature adjustment unit 60. A pipe 11 extending from the upper part of the temperature adjustment unit 60 is connected to the grinding device 100.

[0032] [Function of the pure water recycling device] Next, the operation of the pure water recycling apparatus 1 configured as above will be described.

[0033] In this embodiment, the grinding device 100, which is a processing device, performs grinding processing on the wafer while receiving a supply of pure water from the temperature control unit 60. Specifically, in the grinding device, the back surface of the wafer (the surface opposite to the surface on which the device is formed) is ground by a grinding wheel rotating at high speed to thin the wafer to a predetermined thickness, and during the grinding processing of the wafer, pure water is supplied from a nozzle (not shown) to a contact point (processing point) between the grinding wheel and the wafer. In the grinding device 100, the wafer after the grinding processing is cleaned on its ground surface (back surface) by pure water (cleaning water) sprayed from a cleaning nozzle (not shown) in a cleaning unit, and grinding debris attached to the wafer is washed away.

[0034] As described above, the pure water after use in the grinding device 100 contains grinding debris, organic ions, etc., and the pure water containing the grinding debris, organic ions, etc. is discharged as processing waste liquid into the pipe 2. This processing waste liquid is then supplied through the pipe 2 into the tank 10 and stored in the tank 10.

[0035] The machining waste liquid stored in the tank 10 is pumped up by a pump P and supplied to the machining debris removal filter 20 through a pipe 3, and the grinding debris contained therein is removed and the water is purified as clean water by passing through a filter (not shown) housed in a case 21 of the machining debris removal filter 20. The clean water purified by the machining debris removal filter 20 is then guided through a pipe 4 to an ultraviolet ray irradiation unit 30, and in the process of passing through the ultraviolet ray irradiation unit 30, it is sterilized by being irradiated with ultraviolet rays from a UV lamp (not shown).

[0036] As described above, the fresh water sterilized by irradiation with ultraviolet rays in the ultraviolet irradiation unit 30 is introduced into the electrodeionization exchange unit 40 through the pipe 5. Specifically, as shown in Fig. 2, the fresh water is introduced from the pipe 5 into each of the deionization compartments S1 in the electrodeionization exchange unit 40, and the cations and anions contained in the fresh water are adsorbed onto the ion exchange resin 47. At this time, when a direct current is applied from the DC power source 44 to the anode plate 42 and the cathode plate 43, the cations e adsorbed onto the ion exchange resin 47 in each deionization compartment S1 are adsorbed onto the ion exchange resin 47. + moves toward the cathode plate 43 (to the right in FIG. 2), and the negative ions e - moves toward the anode plate 42 side (the left side in FIG. 2).

[0037] Here, the cation e + passes through the cation exchange membranes 45a, 45b, and 45c, but is prevented from passing through the anion exchange membranes 46a, 46b, and 46c. - passes through the anion exchange membranes 46a, 46b, and 46c, but is prevented from passing through the cation exchange membranes 45a, 45b, and 45c. Therefore, the cations e from both deionization compartments S1 are supplied to the concentration compartment S2 in the center of FIG. + and anion e - In this concentration compartment S2, the positive ions e + and anion e - In addition, the concentration compartment S2 on the left side of Figure 2 is filled with anions e that flow in from the deionization compartment S1 on the other side (the left side of Figure 2). - The concentrated water containing the cations e flowing in from the other deionization chamber S1 (on the right side of FIG. 2) is generated in the concentration chamber S2 on the right side of FIG. + A concentrate containing the compound is produced.

[0038] The negative ions e that flowed into the concentrating compartment S2 on the other side (left side of Figure 2) - Since the cation exchange membrane 45a prevents the cations from flowing into the electrolysis chamber S3 on one side (the left side in FIG. 2), the cations e + and anion e - The electrolytic water that does not contain cations e +Since the anion exchange membrane 46c prevents the anion from flowing into the other electrolysis chamber S3 (the right side of FIG. 2), the cations e + and anion e - Electrolyzed water that does not contain

[0039] As a result of the above, in both desalting compartments S1, the cations e adsorbed on the ion exchange resin 47 + and anion e - This pure water is supplied to the temperature control unit 60 through the pipe 6, and after the temperature is adjusted to a predetermined value by the temperature control unit 60, it is supplied to the grinding device 100 through the pipe 11 and is reused as a processing fluid (grinding fluid) and a cleaning fluid in the grinding device 100. The electrolytic water generated in each electrolysis chamber S3 is returned to the tank 10 through the pipe 8.

[0040] Furthermore, the concentrated water produced in each concentration chamber S2 is supplied to the distilled water production unit 50 through the pipe 7, and reduced to distilled water in the distilled water production unit 50. Here, the operation of the distilled water production unit 50 will be described below with reference to FIG.

[0041] In the distilled water production unit 50 shown in Fig. 3, concentrated water from each concentration chamber S2 of the electrodeionization exchange unit 40 shown in Fig. 2 is supplied from the pipe 7 to a tray 53 in a container 51, and the concentrated water is stored in the tray 53. Then, a part of the concentrated water stored in the tray 53 is sucked up by the suction member 54 due to the capillary phenomenon.

[0042] On the other hand, in the heating section 57A, the cold air cooled in the cooling section 57B is heated to a predetermined temperature to become hot air, and this hot air flows into the vaporization chamber S in the container 51 from the inlet 51b of the container 51. Then, the hot air flowing into the vaporization chamber S generates a turbulent flow in the vaporization chamber S by the circulator F, so that the concentrated water sucked up by the suction member 54 is heated by the hot air caused by the turbulent flow and part of it is vaporized. As a result, the cations e contained in the distilled water are + and anion e -is sucked by the suction member 54 and remains there.

[0043] As described above, the air (gas) containing water vapor resulting from evaporation of a portion of the condensed water sucked up by the suction member 54 becomes hot air and is sucked in from the outlet 51a of the container 51 by the blower B. The hot air sucked in by the blower B is pressurized by the blower B and flows in the duct 55 in the direction of the arrow in the figure, and is cooled by passing through the cooling section 57B. In this way, when the hot air is cooled by the cooling section 57B and the water vapor contained in the hot air falls below the condensation temperature, the water vapor is condensed to generate distilled water in the distilled water acquisition section 58, and the positive ions e + and anion e - Distilled water (pure water) not containing any of the above flows from a nozzle 56a of a case 56 into a pipe 9 shown in Figures 1 and 2. Then, the distilled water that has flowed into the pipe 9 merges with the pure water flowing in the pipe 6 as shown in Figures 1 and 2, and the mixture of the distilled water and the pure water is supplied to the temperature adjustment unit 60 through the pipe 6.

[0044] The mixed water (pure water) of distilled water and pure water supplied to the temperature adjustment unit 60 is adjusted to a predetermined temperature by the temperature adjustment unit 60, and then flows back through the pipe 11 to the grinding device 100, where it is reused as a processing liquid and a cleaning liquid. When the distilled water generation unit 50 repeatedly generates distilled water, the suction member 54 absorbs the cations e contained in the concentrated water. + and anion e - Since the suction member 54 accumulates and its performance deteriorates over time, the suction member 54 is periodically replaced with a new one. In this embodiment, the heating section 57A and the cooling section 56B are configured by the Peltier element 57, but instead of the Peltier element 57, a heater may be disposed on the base 52 to make the base 52 the heating section, and a heat dissipation section to the outside air may be provided to make the cooling section.

[0045] By repeating the above operations, the waste processing liquid discharged from the grinding device 100 is purified into pure water, and this purified pure water is repeatedly reused as the processing liquid and cleaning liquid in the grinding device 100, but in this embodiment, the concentrated water discharged from the electrodeionization exchange unit 40 is evaporated in the distilled water generating unit 50 to generate distilled water (pure water), so that the concentrated water is returned to the grinding device 100 without being discarded, and this distilled water can be reused as pure water. This eliminates the need to replenish pure water, improving the economic effect.

[0046] In the above embodiment, the grinding apparatus 100 has been given as an example of a processing apparatus, but examples of the processing apparatus include a cutting apparatus that cuts a wafer with a disk-shaped cutting blade that rotates at high speed, a polishing apparatus that polishes a wafer with a polishing pad that rotates at high speed, and a cleaning apparatus that cleans a wafer with pure water, in addition to the grinding apparatus 100. Also, the workpiece processed by the processing apparatus is not limited to a wafer, and may be any object other than a wafer.

[0047] In addition, the present invention is not limited to the application of the embodiments described above, and various modifications are possible within the scope of the claims and the technical ideas described in the specification and drawings. [Explanation of symbols]

[0048] 1: Pure water recycling device, 2-9: Piping, 10: Tank, 11: Piping, 20: Processing debris removal filter, 30: Ultraviolet irradiation unit, 40: electrodeionization exchange unit, 41: case, 42: anode plate, 43: cathode plate, 44: DC power supply, 45a to 45c: cation exchange membranes, 46a to 46c: anion exchange membranes, 47: ion exchange resin, 50: distilled water generating unit, 51: container, 51a: outlet, 51b: inlet, 52: stand, 53: tray, 54: suction member, 55: duct (return piping), 56: case, 56a: nozzle, 57: Peltier element, 57A: heating unit, 57B: cooling unit, 58: distilled water acquisition unit, 60: temperature control unit, 100: Grinding equipment (processing equipment), B: Blower, e + : cation, e ― : Anion, F: Circulator, P: Pump, S: Vaporizer, S1: Desalination chamber, S2: Concentration chamber, S3: Electrolysis chamber

Claims

1. a tank for storing wastewater discharged from a processing device that processes a workpiece while receiving a supply of pure water; a processing debris removing filter for removing processing debris from the processing wastewater supplied from the tank to generate clean water; an ultraviolet irradiation unit for irradiating the fresh water with ultraviolet light; an electrodeionization exchange unit for removing organic ions contained in the fresh water by electrodialysis to produce pure water; A pure water recycling apparatus for regenerating the pure water from the processing wastewater discharged from the processing apparatus, A pure water recycling apparatus comprising a distilled water generating unit for evaporating concentrated water discharged from the electrodeionization exchange unit to generate distilled water, and the distilled water is returned to the processing device together with the pure water.

2. The distilled water generating unit comprises: A tray for receiving the concentrated water; A suction member for suctioning the concentrated water stored in the tray; a vaporization chamber containing the tray and the suction member; A heating unit that heats the gas in the vaporization chamber; an outlet for discharging gas from the vaporization chamber; an inlet for introducing a gas into the vaporization chamber; a reflux pipe connecting the outlet and the inlet outside the vaporization chamber; a blower that causes gas to flow through the circulation pipe from the outlet toward the inlet; A cooling unit that cools the gas discharged from the outlet; a distilled water acquiring unit that condenses moisture contained in the gas cooled by the cooling unit to acquire distilled water; 2. The pure water recycling apparatus according to claim 1, further comprising:

3. 3. The pure water recycling apparatus according to claim 2, wherein the heating section and the cooling section are constituted by Peltier elements.

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