Water generating device and chiller device

Abstract

To provide a water generator capable of easily generating water whose electrical conductivity is within a predetermined range.SOLUTION: A water generator includes: a first water supply unit having a first valve that controls the supply of water of a first purity whose electrical conductivity is lower than the lower limit of the target range; a second water supply unit having a second valve that controls the supply of water of a second purity whose electrical conductivity is higher than that of the water of the first purity; a water mixing unit that mixes water of the first purity and water of the second purity to produce third purity water, a measurement unit that measures a physical quantity corresponding to the electrical conductivity of the third purity water, and a control unit having a processing device and a storage device. The storage device stores a first threshold value indicating a physical quantity corresponding to an upper limit of the target range and a second threshold value indicating a physical quantity corresponding to a lower limit of the target range. The control unit compares the physical quantity obtained by the measurement of the measurement unit with the first threshold value and the second threshold value, and determines and adjusts one or both of the opening degrees of the first valve and the second valve.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a water generation device capable of generating water having an electric conductivity within a predetermined range, and a chiller device including the water generation device.

Background Art

[0002] In electronic devices typified by mobile phones and personal computers, a device chip having devices such as an electronic circuit is an essential component. The device chip is obtained, for example, by partitioning the surface side of a wafer made of a semiconductor material such as silicon (Si) into a plurality of regions by streets (lines to be divided), forming devices in each region, and then dividing the wafer along these streets.

[0003] When dividing a wafer into small pieces such as device chips, for example, a laser processing device capable of irradiating the wafer with a laser beam suitable for wafer processing is used. In this laser processing device, since a lot of heat is generated during the generation and irradiation of the laser beam, the easily heat-generating part is cooled by circulating water called cooling water or the like (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a device chip manufacturing factory, generally, two types of water are used: water containing almost no impurities called ultrapure water suitable for cleaning device chips, etc., and tap water containing a lot of impurities and having a high electric conductivity. Therefore, it is desired to use either of these two types of water as the cooling water for cooling a laser processing device or the like.

[0006] However, when ultrapure water containing almost no impurities is used as cooling water, there is a problem in that the metal heat sink that exchanges heat through contact with the cooling water is prone to corrosion. Also, when tap water containing many impurities is used as cooling water, the circulation paths are easily contaminated by the impurities. To prevent such problems, it is necessary to use water with an impurity level within a specified range, that is, water with an electrical conductivity within a specified range, as the cooling water.

[0007] However, as mentioned above, typical device chip manufacturing plants only use two types of water: ultrapure water and tap water. Water with the appropriate electrical conductivity for cooling is not always supplied. Therefore, if water with a different electrical conductivity than the two types mentioned above is required, it must be sourced separately, complicating operations and management.

[0008] Therefore, the object of the present invention is to provide a water generating device that can easily produce water with an electrical conductivity within a predetermined range, and a chiller device including this water generating device. [Means for solving the problem]

[0009] According to one aspect of the present invention, a water generating device that generates water with an electrical conductivity within a target range, Supplied from outside the water generatorThe system includes: a first water supply unit having a first valve for controlling the supply amount of first-purity water having an electrical conductivity lower than the lower limit of the target range; a second water supply unit having a second valve for controlling the supply amount of second-purity water having a higher electrical conductivity than the first-purity water; a water mixing unit located downstream of the first and second water supply units, which mixes the first-purity water supplied from the first water supply unit with the second-purity water supplied from the second water supply unit to produce third-purity water having a higher electrical conductivity than the first-purity water and a lower electrical conductivity than the second-purity water; an ultraviolet irradiation unit having an ultraviolet light source capable of emitting ultraviolet rays, which irradiates the second-purity water supplied from the second water supply unit or the third-purity water produced in the water mixing unit with ultraviolet rays; a measuring unit for measuring a physical quantity corresponding to the electrical conductivity of the third-purity water; and a processing device and a storage device. A water generating device is provided, which includes a control unit that generates signals necessary for controlling the first water supply unit, the second water supply unit, and the ultraviolet irradiation unit according to a program stored in the storage device, the storage device storing a first threshold indicating the physical quantity corresponding to the upper limit of the target range, and a second threshold indicating the physical quantity corresponding to the lower limit of the target range, and the control unit performs the following steps according to the program: comparing the physical quantity obtained by measurement by the measuring unit with the first threshold and the second threshold; determining one or both of the opening degrees of the first valve and the second valve so that the physical quantity obtained by measurement by the measuring unit approaches a value within the range defined by the first threshold and the second threshold; and adjusting one or both of the opening degrees of the first valve and the second valve so that the opening degrees are determined.

[0010] According to another aspect of the present invention, a chiller device for cooling an object by circulating water between the object and the object, comprising: a chiller unit having a cooler for cooling the water; a water channel connected to the object and the chiller unit for circulating the water between the object and the chiller unit; a drain connected to the water channel for discharging the water from the water channel; a water generating device connected to the water channel for generating water with an electrical conductivity within a target range; and a control unit having a processing device and a memory device, wherein the processing device generates signals necessary for controlling the water generating device according to a program stored in the memory device, wherein the water generating device is Supplied from outside the chiller device A first water supply unit having a first valve for controlling the supply amount of first-purity water having an electrical conductivity lower than the lower limit of the target range; a second water supply unit having a second valve for controlling the supply amount of second-purity water having a higher electrical conductivity than the first-purity water; a water mixing unit located downstream of the first and second water supply units, which mixes the first-purity water supplied from the first water supply unit with the second-purity water supplied from the second water supply unit to produce third-purity water having a higher electrical conductivity than the first-purity water and a lower electrical conductivity than the second-purity water; an ultraviolet irradiation unit having an ultraviolet light source capable of emitting ultraviolet light, which irradiates the second-purity water supplied from the second water supply unit or the third-purity water produced in the water mixing unit with ultraviolet light; and the third-purity A chiller device is provided that supplies water to a water channel by performing the following steps: a measuring unit for measuring a physical quantity corresponding to the electrical conductivity of water, the storage device storing a first threshold indicating the physical quantity corresponding to the upper limit of a target range, and a second threshold indicating the physical quantity corresponding to the lower limit of a target range; and a control unit, in accordance with a program, performs the steps of: comparing the physical quantity obtained by the measurement unit with the first and second thresholds; determining the opening of one or both of the first valve and the second valve so that the physical quantity obtained by the measurement unit approaches a value within the range defined by the first and second thresholds; and adjusting one or both of the opening of the first valve and the second valve to achieve the determined opening.

[0011] Preferably, the chiller device further comprises an air passage connected to the waterway and used to supply air to the waterway, and an air supply unit having a third valve for controlling the amount of air supplied to the air passage. [Effects of the Invention]

[0012] A water generating apparatus according to one aspect of the present invention mixes water of first purity, in which the electrical conductivity is lower than the lower limit of a target range, with water of second purity, in which the electrical conductivity is higher than that of water of first purity, to produce water of third purity, in which the electrical conductivity is higher than that of water of first purity and lower than that of water of second purity.

[0013] Furthermore, in a water generating device according to one aspect of the present invention, the opening of the first valve and the opening of the second valve are adjusted, or both are adjusted, so that the measured value of the physical quantity corresponding to the electrical conductivity of the third-purity water approaches a value within the range defined by a first threshold value indicating the upper limit of the target range for electrical conductivity and a second threshold value indicating the lower limit of the target range for electrical conductivity. Thus, this water generating device can easily produce third-purity water with electrical conductivity within the target range from first-purity water and second-purity water.

[0014] Furthermore, a chiller device according to another aspect of the present invention includes, in addition to a chiller unit and a water channel, a water generator configured to perform the same functions as the water generator described above and connected to the water channel. Thus, this chiller device can easily generate water of a third purity, in which the electrical conductivity is within a target range, from water of a first purity and water of a second purity, and supply this water of the third purity to the water channel. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a schematic diagram showing the structure of a water generator. [Figure 2] Figure 2 is a functional block diagram schematically showing the functional structure of the control unit. [Figure 3]Figure 3 is a flowchart showing the series of steps performed when producing water with an electrical conductivity within the target range. [Figure 4] Figure 4 is a schematic diagram showing the structure of a chiller device. [Modes for carrying out the invention]

[0016] Embodiments of the present invention will be described below with reference to the attached drawings. Figure 1 is a schematic diagram showing the structure of the water generator 2 according to this embodiment. In Figure 1, various components constituting the water generator 2 are represented by functional blocks, symbols, etc. As shown in Figure 1, the water generator 2 is configured to produce water of a third purity by mixing water of a first purity supplied from an external first supply source 4 and water of a second purity supplied from an external second supply source 6.

[0017] Specifically, the water generator 2 includes a first water supply unit 8 connected to a first supply source 4 via piping, etc. (not shown), and a second water supply unit 10 connected to a second supply source 6 via piping, etc. (not shown). The first water supply unit 8 has a first valve 12 that can control the amount of water of first purity supplied to the downstream side. The second water supply unit 10 also has a second valve 14 that can control the amount of water of second purity supplied to the downstream side.

[0018] The first valve 12 and the second valve 14 are so-called control valves whose opening degree is adjusted according to the input signal to control the flow rate. Typical control valves include globe valves, butterfly valves, and diaphragm valves. However, other control valves may be used for the first valve 12 and the second valve 14.

[0019] Downstream of the first water supply section 8 and the second water supply section 10, a water mixing section 16 for mixing the water of the first purity supplied from the first water supply section 8 and the water of the second purity supplied from the second water supply section 10 is arranged. The water mixing section 16 is, for example, a container having a mixing chamber suitable for mixing the water of the first purity and the water of the second purity, and is connected to the first water supply section 8 and the second water supply section 10 via piping etc. (not shown).

[0020] Here, the water of the first purity is typically water called ultrapure water with an extremely low impurity content, and its electric conductivity is about 0.0548 μS / cm to 0.1 μS / cm at 25°C. On the other hand, the water of the second purity is typically tap water with a relatively high impurity content, and its electric conductivity is about 40 μS / cm to 400 μS / cm at 25°C. However, as long as the water of the first purity and the water of the second purity have different electric conductivities, they do not have to be ultrapure water or tap water.

[0021] When such water of the first purity and water of the second purity are mixed in the water mixing section 16, water of the third purity with a higher electric conductivity than the water of the first purity and a lower electric conductivity than the water of the second purity is generated. The water of the third purity obtained by mixing the water of the first purity and the water of the second purity in the water mixing section 16 is supplied further downstream from the water mixing section 16. In the present embodiment, a container having a mixing chamber etc. is adopted as the water mixing section 16, but the water mixing section 16 of the present invention may also be piping etc. having a shape and length suitable for mixing two types of water.

[0022] Downstream of the water mixing section 16, an ultraviolet irradiation section 18 is arranged. This ultraviolet irradiation section 18 has an ultraviolet light source 20 (see FIG. 2) capable of emitting ultraviolet rays of a wavelength suitable for decomposition of organic substances and sterilization etc., and irradiates the water of the third purity supplied from the water mixing section 16 with ultraviolet rays to decompose the organic substances contained in the water of the third purity and sterilize the water of the third purity etc.

[0023] For example, a mercury lamp or an ultraviolet LED (Light Emitting Diode) may be used as the ultraviolet light source 20. By providing such an ultraviolet irradiation unit 18, the water generator 2 can produce water of third purity with controlled total organic carbon (TOC). In this embodiment, the total organic carbon of the third-purity water is controlled to, for example, about 100 ppb to 500 ppb.

[0024] In this embodiment, the ultraviolet irradiation unit 18 is located downstream of the water mixing unit 16 and irradiates the water of the third purity with ultraviolet light. However, the ultraviolet irradiation unit 18 of the present invention may be located upstream of the water mixing unit 16 and downstream of the second water supply unit 10. That is, the ultraviolet irradiation unit 18 of the present invention may be configured to irradiate the water of the second purity supplied from the second water supply unit 10 with ultraviolet light.

[0025] Further downstream from the ultraviolet irradiation unit 18, a measuring unit 22 is located that can measure a physical quantity corresponding to the electrical conductivity of water of third purity. Specifically, the measuring unit 22 has an electrical conductivity meter 24 (see Figure 2) that can measure the electrical conductivity of a liquid, and measures the electrical conductivity of water of third purity after irradiation with ultraviolet light.

[0026] In this embodiment, the measurement unit 22 is located downstream of the ultraviolet irradiation unit 18 and measures the electrical conductivity of water of third purity after irradiation with ultraviolet light. However, the measurement unit 22 of the present invention may be located upstream of the ultraviolet irradiation unit 18 and downstream of the water mixing unit 16. That is, the measurement unit 22 of the present invention may be configured to measure the electrical conductivity of water of third purity before irradiation with ultraviolet light.

[0027] Furthermore, in this embodiment, the measuring unit 22 is configured to measure electrical conductivity, but the measuring unit 22 of the present invention only needs to be configured to measure some physical quantity corresponding to electrical conductivity. For example, the measuring unit 22 may be configured to measure electrical resistivity (specific resistance), which has an inverse relationship with electrical conductivity.

[0028] A control unit 26 is connected to the first water supply unit 8, the second water supply unit 10, the ultraviolet irradiation unit 18, the measurement unit 22, etc. of the water generator 2 described above. This control unit 26 is composed of a computer including, for example, a processing unit 28 and a storage device 30, and controls each component of the water generator 2 described above so that two types of water can be mixed to produce water with an electrical conductivity within a target range.

[0029] The processing unit 28 is typically a CPU (Central Processing Unit) and performs various processes necessary to control the components described above. The storage device 30 includes, for example, a main memory such as DRAM (Dynamic Random Access Memory) and an auxiliary storage device such as a hard disk drive or flash memory. The functions of the control unit 26 are realized, for example, by the processing unit 28 operating according to a program stored in the storage device 30.

[0030] Furthermore, an input / output device 32, which serves as a user interface, is connected to the control unit 26. The input / output device 32 is, for example, a touchscreen, which inputs commands from the operator to the control unit 26 and displays information output from the control unit 26. This input / output device 32 may be divided into an input device such as a keyboard or mouse, and an output device (display device) such as a liquid crystal panel or an organic EL (Electro-Luminescence) panel.

[0031] A portion of the storage device 30, which is also a non-temporary recording medium readable by a computer, stores a program that causes the processing device 28 to execute a series of procedures necessary to produce water with an electrical conductivity within the target range. The processing device 28 performs various procedures necessary to produce water with an electrical conductivity within the target range by generating signals necessary for controlling the first water supply unit 8, the second water supply unit 10, and the ultraviolet irradiation unit 18, in accordance with this program.

[0032] Furthermore, the control unit 26 described above may be a control unit capable of controlling other devices in conjunction with it. For example, when the water generator 2 is incorporated into the chiller device 42 (see Figure 4), which will be described later, the control unit 64 (see Figure 4), which is a component of the chiller device 42, may also serve as the control unit 26 of the water generator 2. Thus, the water generator 2 does not necessarily include a control unit 26 as an intrinsic component.

[0033] Figure 2 is a schematic functional block diagram showing the functional structure of the control unit 26 realized by a program stored in the memory device 30, and Figure 3 is a flowchart showing a series of steps performed when generating water with an electrical conductivity within a target range (i.e., the water generation method of this embodiment). For the sake of explanation, Figure 2 also shows the first water supply unit 8, the second water supply unit 10, the ultraviolet irradiation unit 18, the measurement unit 22, etc., which are connected to the control unit 26.

[0034] As shown in Figure 2, the control unit 26 includes a valve opening setting unit 26a that sets the opening degrees of the first valve 12 included in the first water supply unit 8 and the second valve 14 included in the second water supply unit 10. For example, when a command to start a series of procedures is input to the control unit 26 from the operator via the input / output device 32, the valve opening setting unit 26a performs a procedure to set the initial opening degrees of the first valve 12 and the second valve 14 in accordance with the target range of electrical conductivity set by the operator.

[0035] There are no specific restrictions on how the initial opening degree can be set. For example, if a table corresponding to the electrical conductivity of two types of water and the target range is stored in the storage device 30, the valve opening degree setting unit 26a can refer to this table to set the initial opening degrees of the first valve 12 and the second valve 14. If information regarding the initial opening degree is input from the operator, the valve opening degree setting unit 26a can also set the initial opening degrees of the first valve 12 and the second valve 14 based on this input information.

[0036] Furthermore, the control unit 26 includes a valve opening adjustment unit 26b that adjusts the actual opening degrees of the first valve 12 and the second valve 14 according to the opening degrees of the first valve 12 and the second valve 14 set by the valve opening setting unit 26a. For example, when the initial opening degrees of the first valve 12 and the second valve 14 are set by the valve opening setting unit 26a, the valve opening adjustment unit 26b performs a procedure to adjust the actual opening degrees of the first valve 12 and the second valve 14 to match these initial opening degrees.

[0037] As a result, the water mixing unit 16 is supplied with water of first purity and water of second purity (step S11). Specifically, the water mixing unit 16 is supplied with water of first purity from the first water supply unit 8 at a flow rate corresponding to the initial opening of the first valve 12, and with water of second purity from the second water supply unit 10 at a flow rate corresponding to the initial opening of the second valve 14. The water of first purity and water of second purity are mixed in the water mixing unit 16 to become water of third purity.

[0038] At the moment when this third-purity water flows from the water mixing unit 16 to the ultraviolet irradiation unit 18, the ultraviolet irradiation control unit 26c of the control unit 26 performs a procedure to irradiate the third-purity water with ultraviolet light by emitting ultraviolet light from the ultraviolet light source 20. As a result, organic matter contained in the third-purity water is decomposed, or the third-purity water is sterilized.

[0039] Furthermore, the measurement unit 22 measures the electrical conductivity of the third-purity water supplied via the ultraviolet irradiation unit 18 using the electrical conductivity meter 24, and sends this information, i.e., the measured value of electrical conductivity, to the control unit 26 (step S12). In this embodiment, the measurement unit 22 is configured to continuously measure the electrical conductivity of the third-purity water passing through the measurement unit 22 and send the measured value to the control unit 26. However, the measurement unit 22 may be configured to measure the electrical conductivity of the third-purity water at a timing corresponding to a command from the control unit 26.

[0040] When the measured electrical conductivity value obtained by the measurement unit 22 is sent to the control unit 26, the valve opening setting unit 26a performs a procedure to determine whether or not this measured value is within the target range set by the operator (step S13). Specifically, the valve opening setting unit 26a compares the measured electrical conductivity value obtained by the measurement unit 22 with a first threshold corresponding to the upper limit of the target range and a second threshold corresponding to the lower limit of the target range.

[0041] To enable such comparisons, the memory device 30 stores a first threshold corresponding to the upper limit of the target range and a second threshold corresponding to the lower limit of the target range. Furthermore, if other physical quantities, such as electrical resistivity corresponding to electrical conductivity, are measured in the measurement unit 22, the memory device 30 will store, for example, a first threshold indicating that physical quantity corresponding to the upper limit of the target range and a second threshold indicating that physical quantity corresponding to the lower limit of the target range. Of course, the physical quantities measured in the measurement unit 22 may also be converted to electrical conductivity or the like before comparison.

[0042] If the measured electrical conductivity value measured by the measurement unit 22 is not within the target range defined by the first threshold and the second threshold (NO in step S13), the valve opening setting unit 26a determines the opening of the first valve 12 and the opening of the second valve 14 so that the measured electrical conductivity value approaches the value within the target range (step S14).

[0043] For example, if the measured electrical conductivity value measured by the measurement unit 22 is higher than the first threshold, the valve opening setting unit 26a determines the opening of the first valve 12 and the opening of the second valve 14 such that the proportion of water of first purity in the water of third purity becomes relatively large. In other words, the valve opening setting unit 26a determines the opening of the first valve 12 and the opening of the second valve 14 such that the proportion of water of second purity in the water of third purity becomes relatively small.

[0044] More specifically, the valve opening setting unit 26a determines the opening of the first valve 12 to be greater than the opening of the first valve 12 that has already been set, and determines the opening of the second valve 14 to be less than the opening of the second valve 14 that has already been set. In this case, the flow rate of water of the first purity increases and the flow rate of water of the second purity decreases, so the flow rate of the generated water of the third purity does not change significantly.

[0045] Furthermore, for example, if the measured electrical conductivity value measured by the measurement unit 22 is lower than the second threshold, the valve opening setting unit 26a determines the opening of the first valve 12 and the opening of the second valve 14 such that the proportion of water of first purity in the water of third purity becomes relatively small. In other words, the valve opening setting unit 26a determines the opening of the first valve 12 and the opening of the second valve 14 such that the proportion of water of second purity in the water of third purity becomes relatively large.

[0046] More specifically, the valve opening setting unit 26a determines the opening of the first valve 12 to be smaller than the opening of the first valve 12 that has already been set, and determines the opening of the second valve 14 to be larger than the opening of the second valve 14 that has already been set. In this case, the flow rate of water of the first purity decreases and the flow rate of water of the second purity increases, so the flow rate of the generated water of the third purity does not change significantly.

[0047] In this embodiment, the valve opening setting unit 26a is configured to change both the opening of the first valve 12 and the opening of the second valve 14 in order to avoid significantly changing the flow rate of the generated third-purity water. However, the present invention is not limited to this embodiment. The valve opening setting unit 26a may also be configured to change only one of the openings of the first valve 12 or the second valve 14.

[0048] After the valve opening setting unit 26a determines the new openings of the first valve 12 and the second valve 14, the valve opening adjustment unit 26b performs a procedure to adjust the openings of the first valve 12 and the second valve 14 to achieve the new openings determined by the valve opening setting unit 26a (step S15). As a result, the mixing ratio of water of first purity and water of second purity changes, and the electrical conductivity of water of third purity approaches a value within the target range.

[0049] In this embodiment, the valve opening adjustment unit 26b adjusts both the opening degree of the first valve 12 and the opening degree of the second valve 14, but the present invention is not limited to this embodiment. If the valve opening setting unit 26a determines only one of the opening degrees of the first valve 12 or the second valve 14, the valve opening adjustment unit 26b will adjust only one of the opening degrees of the first valve 12 or the second valve 14.

[0050] After the opening degrees of the first valve 12 and the second valve 14 are adjusted, the measurement unit 22 measures the electrical conductivity (step S12), and the valve opening degree setting unit 26a makes a determination (step S13). If the measured value of the electrical conductivity measured by the measurement unit 22 is within the target range defined by the first threshold and the second threshold (YES in step S13), the opening degrees of the first valve 12 and the second valve 14 are maintained thereafter.

[0051] As described above, the water generator 2 according to this embodiment mixes water of first purity, in which the electrical conductivity is lower than the lower limit of the target range, with water of second purity, in which the electrical conductivity is higher than that of first purity water, to produce water of third purity, in which the electrical conductivity is higher than that of first purity water and lower than that of second purity water.

[0052] Furthermore, the water generator 2 according to this embodiment adjusts either or both of the opening degrees of the first valve 12 and the second valve 14 so that the measured value of the physical quantity corresponding to the electrical conductivity of the third-purity water approaches a value within the range defined by a first threshold value indicating the upper limit of the target range for electrical conductivity and a second threshold value indicating the lower limit of the target range for electrical conductivity. Thus, this water generator 2 can easily produce third-purity water with an electrical conductivity within the target range from first-purity water and second-purity water.

[0053] Next, a chiller system including a water generator 2 will be described. Figure 4 is a schematic diagram showing the structure of a chiller system 42 that circulates water to cool an object. As shown in Figure 4, the chiller system 42 includes a chiller unit 44 that cools water. Typically, the chiller unit 44 has a cooler 46 that cools a primary refrigerant, and cools the water, which is the secondary refrigerant, through heat exchange with the primary refrigerant cooled by the cooler 46.

[0054] A water channel 48 is connected to the chiller unit 44, through which water can flow. The water channel 48 is also connected to the laser processing device 102, which is the object to be cooled. The water cooled by the chiller unit 44 is supplied to the laser processing device 102 through the first water channel 48a, which constitutes the water channel 48. The water used to cool the laser processing device 102 is returned to the chiller unit 44 through the second water channel 48b, which also constitutes the water channel 48. In other words, this water channel 48 circulates water between the laser processing device 102 and the chiller unit 44.

[0055] The laser processing apparatus 102 includes a laser oscillator 104 that generates a laser beam with a wavelength suitable for processing a workpiece such as a wafer, a focuser (not shown) that focuses the laser beam, and a chuck-table (not shown) that holds the workpiece. The laser processing apparatus 102 processes the workpiece by moving the focuser and the chuck-table relative to each other while irradiating the workpiece with a laser beam. In this embodiment, the laser processing apparatus 102 is the target of cooling, but other devices may be the target of cooling.

[0056] A drain (drainage channel) 50 is connected to the second water channel 48b, through which water returns from the laser processing device 102 to the chiller unit 44. This drain is used to discharge old water from the second water channel 48b. The drain 50 is equipped with a drainage section 52 for controlling the drainage. Specifically, the drainage section 52 has a drain valve 54 that can control the flow rate of water discharged from the second water channel 48b. The drain valve 54 is a so-called control valve, which can control the flow rate by adjusting its opening degree in response to an input signal.

[0057] Furthermore, the chiller device 42 includes an air supply unit 58 connected to an external third supply source 56 that supplies air. The air supply unit 58 has an air supply valve (third valve) 60 that can control the flow rate of air supplied downstream. The air supply valve 60 is a so-called control valve whose opening degree can be adjusted in response to an input signal to control the flow rate.

[0058] An air passage 62, through which air can flow, is connected downstream of the air supply unit 58. The air passage 62 is also connected to the second water channel 48b. Air supplied from the third supply source 56 and whose supply amount is controlled by the air supply unit 58 is supplied to the water channel 48 through this air passage 62. For example, when draining water from the water channel 48 through the drain 50, air is supplied to the water channel 48 through this air passage 62. This makes it easier to drain water from the water channel 48.

[0059] Furthermore, the second water channel 48b is connected to the aforementioned water generator 2, which can generate new water with an electrical conductivity within the target range and supply it to the water channel 48. In this chiller device 42, the control unit 64 that controls the entire chiller device 42 also serves as the control unit 26 of the water generator 2, and the water generator 2 does not include a control unit 26 as an inherent component.

[0060] The control unit 64, like the control unit 26, is composed of a computer including, for example, a processing unit and a storage device, and controls these components so that water generation in the water generator 2, water cooling by the chiller unit 44, drainage by the drainage unit 52, and air supply by the air supply unit 58 are properly realized. The functions of this control unit 64 are also realized, for example, by the processing unit operating according to a program stored in the storage device.

[0061] The chiller device 42 configured in this way includes a chiller unit 44, a water channel 48, and a water generator 2 connected to the water channel 48. Therefore, this chiller device 42 can easily generate water of a third purity, in which the electrical conductivity is within the target range, from water of a first purity and water of a second purity, and supply this water of the third purity to the water channel 48.

[0062] It should be noted that the present invention is not limited to the embodiments described above and can be implemented with various modifications. For example, in the embodiments described above, when the measured value of electrical conductivity measured by the measuring unit 22 is within the target range defined by the first threshold and the second threshold (YES in step S13), the opening degree of the first valve 12 and the opening degree of the second valve 14 are maintained as they are. However, the present invention is not limited to this embodiment.

[0063] For example, even if the measured electrical conductivity value obtained by the measurement unit 22 is within the target range, the opening degrees of the first valve 12 and the second valve 14 may be finely adjusted. Typically, the measured electrical conductivity value obtained by the measurement unit 22 is compared with the central value (or central range) of the target range, and the opening degrees of the first valve 12 and the second valve 14 are finely adjusted to bring the measured value closer to the central value (central range) of the target range. This results in water of a third purity with more precisely adjusted electrical conductivity.

[0064] Furthermore, in the embodiment described above, the water that has passed through the measuring unit 22 is supplied directly to the destination, but the water that has passed through the measuring unit 22 may be stored in a temporary storage container, for example. That is, the water generator 2 may further include a container that can temporarily store the water that has passed through the measuring unit 22.

[0065] Immediately after water generation begins, the electrical conductivity of the water passing through the measurement unit 22 is likely to be outside the target range. Therefore, the water that has passed through the measurement unit 22 is temporarily stored to average its electrical conductivity, thereby enabling effective use of the generated water. In this case, it is desirable to provide an additional measurement unit that can measure the electrical conductivity of the water stored in the container. The configuration of this measurement unit may be the same as that of the measurement unit 22.

[0066] Furthermore, the structures, methods, etc., of the embodiments and modified versions described above can be modified as appropriate without departing from the scope of the present invention. [Explanation of Symbols]

[0067] 2:Water generator 4 :1st source 6 :Second source 8: 1st water supply section 10:Second water supply section 12: First valve 14: Second valve 16:Water mixing section 18: UV irradiation area 20: Ultraviolet light source 22: Measuring part 24: Electrical conductivity meter 26: Control Unit 26a: Valve opening setting section 26b: Valve opening adjustment section 26c: Ultraviolet irradiation control unit 28: Processing device 30: Storage device 32: Input / Output Devices 42: Chiller device 44: Chiller Unit 46:Cooler 48: Waterway 48a: 1st waterway 48b: 2nd waterway 50: Drain 52: Drainage section 54: Drain valve 56 :Third supply source 58: Air supply unit 60: Air supply valve (3rd valve) 62: Airflow path 64: Control Unit 102: Laser processing equipment 104: Laser Oscillator

Claims

1. A water generating device that generates water with an electrical conductivity within a target range, A first water supply unit having a first valve that controls the amount of water supplied from outside the water generator, which has an electrical conductivity lower than the lower limit of the target range, A second water supply unit having a second valve for controlling the supply amount of water of a second purity, which has a higher electrical conductivity than water of a first purity, A water mixing unit is located downstream of the first water supply unit and the second water supply unit, and mixes the first-purity water supplied from the first water supply unit with the second-purity water supplied from the second water supply unit to produce a third-purity water having higher electrical conductivity than the first-purity water and lower electrical conductivity than the second-purity water. An ultraviolet irradiation unit having an ultraviolet light source capable of emitting ultraviolet light, which irradiates the second purity water supplied from the second water supply unit or the third purity water generated in the water mixing unit with ultraviolet light, A measuring unit for measuring a physical quantity corresponding to the electrical conductivity of the third purity water, The apparatus includes a processing unit and a storage device, and the processing unit generates signals necessary for controlling the first water supply unit, the second water supply unit, and the ultraviolet irradiation unit according to a program stored in the storage device, The storage device stores a first threshold value indicating the physical quantity corresponding to the upper limit of the target range, and a second threshold value indicating the physical quantity corresponding to the lower limit of the target range. The control unit, in accordance with the program, A procedure for comparing the physical quantity obtained by measurement by the measuring unit with the first threshold and the second threshold, A procedure for determining one or both of the opening degrees of the first valve and the opening degrees of the second valve such that the physical quantity obtained by measurement by the measuring unit approaches a value within the range defined by the first threshold and the second threshold, A water generating apparatus that performs a procedure for adjusting one or both of the opening degrees of the first valve and the opening degree of the second valve to achieve a determined opening degree.

2. A chiller device that cools an object by circulating water between it and the object to be cooled, A chiller unit having a cooler for cooling the water, A water channel connected to the object and the chiller unit, which circulates the water between the object and the chiller unit, A drain connected to the waterway and used to discharge the water from the waterway, A water generating device connected to the waterway, which generates water with an electrical conductivity within a target range, It includes a processing device and a storage device, and a control unit in which the processing device generates signals necessary for controlling the water generating device according to a program stored in the storage device, The water generating device is A first water supply unit having a first valve that controls the amount of water supplied from outside the chiller device, which has an electrical conductivity lower than the lower limit of the target range, A second water supply unit having a second valve for controlling the supply amount of water of a second purity, which has a higher electrical conductivity than water of a first purity, A water mixing unit is located downstream of the first water supply unit and the second water supply unit, and mixes the first-purity water supplied from the first water supply unit with the second-purity water supplied from the second water supply unit to produce a third-purity water having higher electrical conductivity than the first-purity water and lower electrical conductivity than the second-purity water. An ultraviolet irradiation unit having an ultraviolet light source capable of emitting ultraviolet light, which irradiates the second purity water supplied from the second water supply unit or the third purity water generated in the water mixing unit with ultraviolet light, It includes a measuring unit for measuring a physical quantity corresponding to the electrical conductivity of water of the third purity, The storage device stores a first threshold value indicating the physical quantity corresponding to the upper limit of the target range, and a second threshold value indicating the physical quantity corresponding to the lower limit of the target range. The control unit, in accordance with the program, A procedure for comparing the physical quantity obtained by measurement by the measuring unit with the first threshold and the second threshold, A procedure for determining one or both of the opening degrees of the first valve and the opening degrees of the second valve such that the physical quantity obtained by measurement by the measuring unit approaches a value within the range defined by the first threshold and the second threshold, A chiller device that supplies water to a waterway by performing a procedure for adjusting one or both of the openings of the first valve and the second valve to achieve a determined opening.

3. An air passage connected to the waterway and used to supply air to the waterway, The chiller device according to claim 2, further comprising an air supply unit having a third valve for controlling the amount of air supplied to the air passage.

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