Water circulation system

Abstract

A washing system (100) including: a filter (28) for purifying first alkaline ionized water (WA1) discharged from a washing tank of a washing machine (1); a tank (21) for storing the first alkaline ionized water (WA1) purified by the filter (28); a path forming unit (41) forming a circulation path (R1) for the first alkaline ionized water (WA1) passing through the filter (28), the tank (21), and the washing tank; and an ionized water supply unit (30) for supplying, to the tank (21), second alkaline ionized water (WA2) which increases the pH value of the first alkaline ionized water (WA1) in the tank (21).

Description

Water circulation system

[0001] The present disclosure relates to a water circulation system.

[0002] Washing machines that wash laundry items using ionized water such as alkaline ionized water are known (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2002-224628

[0004] By the way, in an emergency such as during a disaster when tap water cannot be used, it is desirable to reuse the alkaline ionized water discharged from the washing machine. In contrast, a water circulation device provided with a filter and a tank and capable of circulating alkaline ionized water along a circulation path passing through the washing machine, the filter, and the tank can be used to reuse the alkaline ionized water discharged from the washing machine.

[0005] Here, the pH value of alkaline ionized water decreases when it is used for washing in the washing machine. When the alkaline ionized water with a decreased pH value is stored in the tank, mold may grow in the tank due to fine dirt remaining in the alkaline ionized water.

[0006] An object of the present disclosure is to provide a water circulation system capable of sterilizing the inside of a tank.

[0007] A water circulation system according to one aspect of the present disclosure includes a filter, a tank, a path forming unit, and a first supply unit. The filter purifies the first alkaline ionized water discharged from the washing tub of the washing machine. The tank stores the first alkaline ionized water purified by the filter. The path forming unit forms a circulation path of the first alkaline ionized water passing through the filter, the tank, and the washing tub. The first supply unit supplies a specific substance that raises the pH value of the first alkaline ionized water in the tank to the tank.

[0008] According to the present disclosure, the inside of the tank can be sterilized.

[0009] Figure 1 is a diagram showing the configuration of a washing system according to an embodiment of the present disclosure. Figure 2 is a cross-sectional view showing the configuration of the washing machine in the washing system according to an embodiment of the present disclosure. Figure 3 is a block diagram showing the control system of the washing system according to an embodiment of the present disclosure. Figure 4 is a perspective view showing the configuration of the tank in the washing system according to an embodiment of the present disclosure. Figure 5 is a flowchart showing an example of a supply process performed in the washing system according to an embodiment of the present disclosure. Figure 6 is a diagram showing the change in the pH value of the first alkaline ionized water stored in the tank of the washing system according to an embodiment of the present disclosure.

[0010] The embodiments of this disclosure will be described below with reference to the attached drawings. Note that the following embodiments are merely examples of embodiments of this disclosure and do not limit the technical scope of this disclosure.

[0011] [Configuration of the washing system 100] First, the configuration of the washing system 100 will be explained with reference to Figure 1. In Figure 1, the circulation path R1 is shown as a dashed line.

[0012] In this disclosure, "washing machine" refers to all equipment that performs various processes on laundry, such as washing. Processes performed on laundry in a washing machine include, for example, washing, drying, deodorizing, and disinfecting. Laundry is not particularly limited as long as it is made of a material suitable for washing with alkaline ionized water. Examples of laundry include products made of cotton or synthetic fibers. Examples of laundry include clothing such as clothes, hats, and gloves; fashion accessories such as shoes, bags, handkerchiefs, and towels; interior furnishings such as curtains and carpets; and bedding such as blankets, towels, and duvet covers.

[0013] The washing system 100 washes clothes and other items to be washed using first alkaline ionized water WA1 (see Figure 1) stored in a tank 21 (see Figure 1). As shown in Figure 1, the washing system 100 comprises a washing machine 1 and a water circulation device 2. The washing system 100 is an example of the water circulation system of the present disclosure. The water circulation system of the present disclosure may also consist of a water circulation device 2.

[0014] [Configuration of Washing Machine 1] Next, the configuration of washing machine 1 will be explained with reference to Figures 1 to 3.

[0015] As shown in Figures 1 and 2, the washing machine 1 comprises a housing 11, a door 12, a washing tub 13, a rotating drum 14, a motor 15, a water supply channel 16, and a drain channel 17. The washing machine 1 also comprises an operation display unit 18 and a control unit 19, as shown in Figure 3.

[0016] The housing 11 houses the various components of the washing machine 1. The housing 11 is formed in a substantially rectangular parallelepiped shape. As shown in Figure 2, an inclined surface is provided on the upper side of one side of the housing 11, which is the front of the washing machine 1, and slopes toward the top surface of the housing 11. A circular opening 11A is provided in the inclined surface. The opening 11A is used for loading laundry into the rotating drum 14 inside the housing 11 and for retrieving laundry from the rotating drum 14. A water inlet 11B is provided on the rear side of the top surface of the housing 11. The water inlet 11B is connected to the second water channel 24 (see Figure 1) of the water circulation device 2. The water inlet 11B is used to supply water to the washing tub 13 inside the housing 11. A drain outlet 11C is provided on the lower side of the left side of the housing 11. The drain outlet 11C is connected to the third water channel 25 (see Figure 1) of the water circulation device 2. The drain port 11C is used for draining water from the washing tub 13 inside the housing 11. Four legs 11D (see Figure 2) are provided on the bottom surface of the housing 11. The four legs 11D are positioned at the four corners of the bottom surface of the housing 11. The drain port 11C may also be provided on the lower right side or bottom surface of the housing 11. The housing 11 may also have five or more legs 11D.

[0017] The door 12 is provided so as to be able to open and close the opening 11A. For example, the door 12 is formed in the shape of a disc. The door 12 is attached to the opening 11A via a hinge (not shown) provided on either the left or right side of the opening 11A.

[0018] The washing tub 13 stores the first alkaline ionized water WA1 (see Figure 1) supplied from the tank 21 when washing laundry. The washing tub 13 is formed in a cylindrical shape with only one side open in the axial direction. That is, the washing tub 13 has a circular opening 13A (see Figure 2). As shown in Figure 2, the washing tub 13 is fixedly positioned inside the housing 11 with the opening 13A facing the opening 11A of the housing 11. A water inlet 13B is provided on the upper side of the washing tub 13. The water inlet 13B is connected to the water inlet 11B of the housing 11 via a water supply channel 16. The water inlet 13B is used to supply water to the washing tub 13. A drain outlet 13C is provided on the lower side of the washing tub 13. The drain outlet 13C is connected to the drain outlet 11C of the housing 11 via a drain channel 17. The drain outlet 13C is used to drain water from the washing tub 13.

[0019] The rotating drum 14 holds the laundry to be washed. The rotating drum 14 is formed in a cylindrical shape with only one side open in the axial direction. In other words, the rotating drum 14 has a circular opening 14A (see Figure 2). The radial size of the rotating drum 14 is smaller than that of the washing tub 13. As shown in Figure 2, the rotating drum 14 is positioned inside the washing tub 13 such that the opening 14A faces the opening 11A of the housing 11. The rotating drum 14 is also rotatable inside the washing tub 13 around its central axis (rotation axis). The side surface of the rotating drum 14 is provided with numerous water passages (not shown) for supplying the first alkaline ionized water WA1 stored in the washing tub 13 to the inside of the rotating drum 14.

[0020] The washing machine 1 is a so-called slanted drum type washing machine, in which the rotating drum 14 is positioned at an angle. Specifically, the rotating drum 14 is positioned such that its central axis is perpendicular to the inclined surface of the housing 11. The angle of inclination of the rotating drum 14 with respect to the horizontal plane is set within the range of 5 to 30 degrees, taking into consideration water-saving effect, washing power, susceptibility to damage to laundry, and ease of removing laundry after washing. Note that the washing machine 1 is not limited to the so-called slanted drum type, but may also be a so-called horizontal type washing machine in which the central axis of the rotating drum 14 is positioned horizontally.

[0021] The motor 15 supplies rotational driving force to the rotating drum 14. The rotating drum 14 rotates around the central axis in response to the rotational driving force supplied by the motor 15. As shown in Figure 3, the motor 15 is connected to the control unit 19 and is driven and controlled by the control unit 19.

[0022] The water supply channel 16 is a water channel from the water inlet 11B of the housing 11 to the water inlet 13B of the washing tub 13. As shown in Figure 2, a water supply valve 16A is provided in the water supply channel 16. The water supply valve 16A is a solenoid valve or electric valve that changes state between an open state that allows water to pass through and a closed state that prohibits water to pass through. As shown in Figure 3, the water supply valve 16A is connected to the control unit 19 and is driven and controlled by the control unit 19.

[0023] The drain channel 17 is a waterway from the drain port 13C of the washing tub 13 to the drain port 11C of the housing 11. As shown in Figure 2, the drain channel 17 is provided with a drain valve 17A and a drain filter 17B. The drain valve 17A is a solenoid valve or electric valve that changes state between an open state that allows water to pass through and a closed state that prohibits water to pass through. As shown in Figure 3, the drain valve 17A is connected to the control unit 19 and is driven and controlled by the control unit 19. The drain filter 17B captures foreign matter such as lint contained in the first alkaline ionized water WA1 that passes through the drain channel 17 after washing.

[0024] The operation display unit 18 (see Figure 3) is the user interface of the washing system 100. The operation display unit 18 comprises a display unit and an operation unit. The display unit displays various information in response to control instructions from the control unit 19. For example, the display unit is a flat panel display such as a liquid crystal display. The operation unit inputs various information to the control unit 19 in response to user operations. For example, the operation unit includes hard keys and a touch panel.

[0025] The control unit 19 (see Figure 3) comprehensively controls the washing system 100. As shown in Figure 3, the control unit 19 comprises a CPU 19A, a ROM 19B, and a RAM 19C. The CPU 19A is a processor that performs various arithmetic operations. The ROM 19B is a non-volatile memory device in which information such as control programs for causing the CPU 19A to perform various operations is pre-stored; in other words, it is a recording medium that can be read by a computer. The RAM 19C is a volatile or non-volatile memory device used as a temporary storage memory (work area) for the various operations performed by the CPU 19A. The CPU 19A executes the various control programs pre-stored in the ROM 19B. In this way, the CPU 19A comprehensively controls the washing system 100.

[0026] [Configuration of Water Circulation Device 2] Next, the configuration of the water circulation device 2 will be described with reference to Figures 1 and 3.

[0027] As shown in Figure 1, the water circulation device 2 comprises a tank 21, a first water channel 22, a first pump 23, a second water channel 24, a third water channel 25, a second pump 26, a fourth water channel 27, a filter 28, a fifth water channel 29, an ionized water supply unit 30, and a neutral water supply unit 31. The water circulation device 2 also comprises an operation display unit 32, a float sensor 33, and a pH sensor 34, as shown in Figure 3.

[0028] Tank 21 stores the first alkaline ionized water WA1 (see Figure 1).

[0029] In the washing system 100, the first alkaline ionized water WA1 stored in the tank 21 is supplied to the washing tub 13 of the washing machine 1 (see Figure 2). In addition, the first alkaline ionized water WA1 discharged from the washing tub 13 of the washing machine 1 and purified by the filter 28 (see Figure 1) is supplied to the tank 21. In other words, the tank 21 stores the first alkaline ionized water WA1 purified by the filter 28. In this specification, the first alkaline ionized water WA1 is alkaline water circulated along the circulation path R1 (see Figure 1). For example, the first alkaline ionized water WA1 is alkaline water with a pH value of 11.0 or less.

[0030] Tank 21 is sized to store the amount of first alkaline ionized water WA1 necessary for the washing operation of the washing machine 1. Tank 21 is located on the side, bottom, top, or inside of the washing machine 1.

[0031] As shown in Figure 1, the tank 21 is equipped with a water inlet 21A, a drain port 21B, a first supply port 21C, and a second supply port 21D. The water inlet 21A is used to supply the first alkaline ionized water WA1, which is discharged from the washing tub 13 (see Figure 2) of the washing machine 1 and purified by the filter 28, to the tank 21. The drain port 21B is used to discharge the first alkaline ionized water WA1 stored in the tank 21 to the washing tub 13. The drain port 21B leads to the washing tub 13 along the circulation path R1 (see Figure 1). The first supply port 21C is used to supply the second alkaline ionized water WA2 (see Figure 1) by the ionized water supply unit 30. The second supply port 21D is used to supply neutral water WA3 (see Figure 1) by the neutral water supply unit 31.

[0032] As shown in Figure 1, the first waterway 22 is a waterway from the drain port 21B of the tank 21 to the first pump 23. For example, the first waterway 22 is formed by a tubular member such as a resin hose.

[0033] The first pump 23 flows the first alkaline ionized water WA1 from the tank 21 side to the washing machine 1 side along a water supply path (see Figure 1) that goes from the drain port 21B of the tank 21 through the first water channel 22, the first pump 23, and the second water channel 24 to the water inlet 11B of the washing machine 1. As shown in Figure 3, the first pump 23 is connected to the control unit 19 and is driven and controlled by the control unit 19.

[0034] As shown in Figure 1, the second water channel 24 is a water channel from the first pump 23 to the water inlet 11B of the washing machine 1. For example, the second water channel 24 is formed by a tubular member such as a resin hose.

[0035] As shown in Figure 1, the third waterway 25 is a waterway leading from the drain port 11C of the washing machine 1 to the second pump 26. For example, the third waterway 25 is formed by a tubular member such as a resin hose.

[0036] The second pump 26 causes the first alkaline ionized water WA1 to flow from the washing machine 1 side to the tank 21 side along a drainage path (see Figure 1) that goes from the drain port 11C of the washing machine 1 through the third water channel 25, the second pump 26, the fourth water channel 27, the filter 28, and the fifth water channel 29 to the water inlet 21A of the tank 21. As shown in Figure 3, the second pump 26 is connected to the control unit 19 and is driven and controlled by the control unit 19.

[0037] As shown in Figure 1, the fourth water channel 27 is a water channel from the second pump 26 to the filter 28. For example, the fourth water channel 27 is formed by a tubular member such as a resin hose.

[0038] The filter 28 purifies the first alkaline ionized water WA1 discharged from the washing tub 13 (see Figure 2) of the washing machine 1. For example, the filter 28 has a two-layer structure having a first layer made of a nonwoven fabric filter and a second layer made of an activated carbon filter. The first layer is positioned upstream of the second layer in the direction of water flow in the drainage path. The second layer may be a hollow fiber membrane filter, a ceramic filter, a reverse osmosis membrane filter, or an ion exchange resin filter. The filter 28 may also have a single-layer structure or a multilayer structure of three or more layers. When the filter 28 has a multilayer structure of three or more layers, the filter 28 may contain multiple filters of different types.

[0039] As shown in Figure 1, the fifth water channel 29 is a water channel leading from the filter 28 to the water inlet 21A of the tank 21. For example, the fifth water channel 29 is formed by a tubular member such as a resin hose.

[0040] The tank 21, the first water channel 22, the first pump 23, the second water channel 24, the third water channel 25, the second pump 26, the fourth water channel 27, the filter 28, and the fifth water channel 29 constitute a path forming section 41 (see Figure 1). The path forming section 41 forms a circulation path R1 (see Figure 1) for the first alkaline ionized water WA1 that passes through the filter 28, the tank 21, and the washing tub 13 of the washing machine 1 (see Figure 2).

[0041] Specifically, the circulation path R1 starts from the tank 21, passes through the first waterway 22, the first pump 23, and the second waterway 24, then through the water supply path 16, the washing tub 13, and the drain path 17 in the washing machine 1, and further passes through the third waterway 25, the second pump 26, the fourth waterway 27, the filter 28, and the fifth waterway 29 to reach the tank 21.

[0042] In the circulation path R1, the first alkaline ion water WA1 flows along the circulation direction D1 shown in FIG. 1 by the first pump 23 and the second pump 26.

[0043] Thus, the washing system 100 can reuse the first alkaline ion water WA1 discharged from the washing machine 1. Thereby, for example, in an emergency such as a disaster when tap water cannot be used, it is possible to meet the demands of users who desire to reuse the first alkaline ion water WA1 discharged from the washing machine 1.

[0044] Here, the pH value of the first alkaline ion water WA1 decreases when it is used for washing in the washing machine 1. Specifically, the pH value of the first alkaline ion water WA1 decreases due to the dirt attached to the laundry and contact with carbon dioxide in the air. When the first alkaline ion water WA1 with a decreased pH value is stored in the tank 21, mold may grow in the tank 21 due to the fine dirt remaining in the first alkaline ion water WA1.

[0045] In contrast, in the washing system 100, as will be described below, the inside of the tank 21 can be sterilized.

[0046] The ion water supply unit 30 supplies the second alkaline ion water WA2 (see FIG. 1) (an example of the specific substance of the present disclosure), which raises the pH value of the first alkaline ion water WA1 in the tank 21, to the tank 21. The second alkaline ion water WA2 is alkaline water with a higher pH value than the first alkaline ion water WA1. For example, the second alkaline ion water WA2 is alkaline water with a pH value of 12.5 or more. Note that the specific substance of the present disclosure may also be a solid agent or the like that can raise the pH value of the first alkaline ion water WA1 in the tank 21. The ion water supply unit 30 is an example of the first supply unit of the present disclosure.

[0047] As shown in FIG. 1, the ionized water supply unit 30 includes an ionized water storage unit 30A, an ionized water supply passage 30B, and an ionized water supply pump 30C. The ionized water storage unit 30A stores the second alkaline ionized water WA2. The ionized water supply passage 30B is a water passage that extends from the ionized water storage unit 30A to the first supply port 21C of the tank 21. The ionized water supply pump 30C is provided in the ionized water storage unit 30A and is a submersible pump that causes the second alkaline ionized water WA2 to flow from the side of the ionized water storage unit 30A toward the tank 21 along the ionized water supply passage 30B. The ionized water supply pump 30C is connected to the control unit 19 (see FIG. 3) and is driven and controlled by the control unit 19.

[0048] In the washing system 100, as washing is repeated, the pH value of the first alkaline ionized water WA1 in the tank 21 gradually decreases. In contrast, in the washing system 100, the ionized water supply unit 30 is used to supply the second alkaline ionized water WA2 to the tank 21. Thereby, it is possible to keep the pH value of the first alkaline ionized water WA1 in the tank 21 within a certain range.

[0049] The neutral water supply unit 31 supplies neutral water WA3 (see FIG. 1) to the tank 21. For example, the neutral water WA3 is tap water stored in advance for emergencies. Note that the neutral water WA3 may be rainwater, river water, lake water, or pond water, and is preferably water that has been purified in advance by a water purifier (not shown). The neutral water supply unit 31 is an example of the second supply unit of the present disclosure.

[0050] As shown in FIG. 1, the neutral water supply unit 31 includes a neutral water storage unit 31A, a neutral water supply passage 31B, and a neutral water supply pump 31C. The neutral water storage unit 31A stores the neutral water WA3. The neutral water supply passage 31B is a water passage that extends from the neutral water storage unit 31A to the second supply port 21D of the tank 21. The neutral water supply pump 31C is provided in the neutral water storage unit 31A and is a submersible pump that causes the neutral water WA3 to flow from the side of the neutral water storage unit 31A toward the tank 21 along the neutral water supply passage 31B. The neutral water supply pump 31C is connected to the control unit 19 (see FIG. 3) and is driven and controlled by the control unit 19.

[0051] When laundry is washed in the washing machine 1, some of the first alkaline ionized water WA1 used for washing is absorbed by the laundry. As a result, in the washing system 100, the amount of first alkaline ionized water WA1 stored in the tank 21 gradually decreases as washing is repeated. In response to this, the washing system 100 uses a neutral water supply unit 31 to supply neutral water WA3 to the tank 21. This makes it possible to keep the amount of first alkaline ionized water WA1 stored in the tank 21 within a certain range.

[0052] The operation display unit 32 is provided on the outer surface of the tank 21. For example, the operation display unit 32 is provided on the top or side surface of the tank 21. The operation display unit 32 is the user interface of the water circulation device 2. For example, the operation display unit 32 has the same configuration as the operation display unit 18 of the washing machine 1.

[0053] As shown in Figure 1, the float sensor 33 is installed inside the tank 21. The float sensor 33 detects the water level in the tank 21. As shown in Figure 3, the float sensor 33 is connected to the control unit 19. In response to instructions from the control unit 19, the float sensor 33 outputs a first detection signal to the control unit 19 indicating the water level in the tank 21 detected by the float sensor 33. Based on the first detection signal, the control unit 19 determines whether the water level in the tank 21 is above a predetermined reference position. The reference position is set based on the water level in the tank 21 when it stores the minimum amount of first alkaline ionized water WA1 necessary for the washing operation by the washing machine 1.

[0054] As shown in Figure 1, the pH sensor 34 is installed inside the tank 21. The pH sensor 34 detects the pH value of the first alkaline ionized water WA1 stored in the tank 21. As shown in Figure 3, the pH sensor 34 is connected to the control unit 19. In response to instructions from the control unit 19, the pH sensor 34 inputs a second detection signal to the control unit 19 indicating the pH value of the first alkaline ionized water WA1 stored in the tank 21.

[0055] [Configuration of Tank 21] Next, the configuration of tank 21 will be explained in more detail with reference to Figure 4. Note that the float sensor 33 is not shown in Figure 4.

[0056] As shown in Figure 4, the tank 21 is formed in a substantially rectangular parallelepiped shape. That is, the tank 21 comprises a bottom portion that forms the bottom surface, four side wall portions that each form a side wall, and a top portion that forms the top surface. The tank 21 also has a first corner portion 21E and a second corner portion 21F that are opposite each other in the horizontal direction. The tank 21 also has a third corner portion 21G and a fourth corner portion 21H that are opposite each other in the horizontal direction. A storage space for storing the first alkaline ionized water WA1 is formed inside the tank 21.

[0057] As shown in Figure 4, the water inlet 21A is provided at the first corner 21E of the tank 21 (an example of the first end portion of this disclosure). Specifically, the water inlet 21A is provided at one of the two side wall portions that form the first corner 21E. Furthermore, the water inlet 21A is provided above the water level of the first alkaline ionized water WA1 stored in the tank 21. Note that the water inlet 21A may be provided at the top surface instead of the side wall portion.

[0058] Furthermore, as shown in Figure 4, the drain port 21B is provided at the second corner 21F of the tank 21 (an example of the second end portion of this disclosure). Specifically, the drain port 21B is provided at one of the two side wall portions that form the second corner 21F. Also, the drain port 21B is provided below the water level of the first alkaline ionized water WA1 stored in the tank 21. Note that the drain port 21B may be provided at the bottom surface instead of the side wall portion.

[0059] By providing a water inlet 21A at the first end of a pair of horizontally opposing ends of the tank 21, and a drain port 21B at the second end of the pair of ends, which is different from the first end, it is possible to increase the distance between the water inlet 21A and the drain port 21B in the horizontal direction. This makes it possible to avoid supplying the first alkaline ionized water WA1 with a low pH value near the water inlet 21A to the washing machine 1 side from the drain port 21B, compared to a configuration in which the distance between the water inlet 21A and the drain port 21B in the horizontal direction is short. In addition, it is possible to reduce the portion in the tank 21 where the first alkaline ionized water WA1 remains.

[0060] Furthermore, by designating the first end as the first corner portion 21E and the second end as the second corner portion 21F, it is possible to maximize the distance between the water inlet 21A and the drain outlet 21B in the horizontal direction.

[0061] As shown in Figure 4, the first supply port 21C is provided in the third corner 21G of the tank 21. Specifically, the first supply port 21C is provided in one of the two side wall portions that form the third corner 21G. Furthermore, the first supply port 21C is provided above the water level of the first alkaline ionized water WA1 stored in the tank 21. Note that the first supply port 21C may also be provided in the upper surface portion instead of the side wall portion.

[0062] Furthermore, as shown in Figure 4, the second supply port 21D is provided in the third corner 21G of the tank 21. Specifically, the second supply port 21D is provided adjacent to the first supply port 21C in the side wall portion where the first supply port 21C is provided. Also, the second supply port 21D is provided above the water level of the first alkaline ionized water WA1 stored in the tank 21. Note that the second supply port 21D may be provided in the upper surface portion instead of the side wall portion.

[0063] By providing the first supply port 21C and the second supply port 21D in the third corner portion 21G, it is possible to suppress the accumulation of the first alkaline ionized water WA1 in the third corner portion 21G, compared to a configuration in which the first supply port 21C and the second supply port 21D are provided in the first corner portion 21E or the second corner portion 21F.

[0064] Furthermore, by positioning both the first supply port 21C and the second supply port 21D close to each other in the third corner 21G, it is possible to suppress the decrease in the pH value of the first alkaline ionized water WA1 near the second supply port 21D, where neutral water WA3 is supplied, compared to a configuration in which the first supply port 21C and the second supply port 21D are spaced apart in the third corner 21G and the fourth corner 21H. In other words, it is possible to suppress the decrease in the disinfecting power of the first alkaline ionized water WA1 near the second supply port 21D.

[0065] Furthermore, in order to prevent the first alkaline ionized water WA1 from accumulating in the fourth corner 21H, the ionized water supply channel 30B may be branched into a channel leading to a first supply port 21C provided in the third corner 21G and a channel leading to another first supply port 21C provided in the fourth corner 21H, and the neutral water supply channel 31B may be branched into a channel leading to a second supply port 21D provided in the third corner 21G and a channel leading to another second supply port 21D provided in the fourth corner 21H.

[0066] As shown in Figure 4, the pH sensor 34 is elongated in the vertical direction and is installed so as to penetrate the upper surface of the tank 21. The pH sensor 34 is installed at the second corner 21F. In other words, the pH sensor 34 is installed near the drain port 21B. Furthermore, the pH sensor 34 is installed at the position furthest from the water inlet 21A in the horizontal direction. This makes it possible to detect the pH value of the first alkaline ionized water WA1 just before it passes through the drain port 21B. In addition, it is possible to suppress the adhesion of fine dirt remaining in the first alkaline ionized water WA1 after washing, supplied from the water inlet 21A, to the pH sensor 34.

[0067] [Configuration of the control unit 19] Next, the configuration of the control unit 19 will be described with reference to Figures 1 and 3.

[0068] As shown in Figure 3, the control unit 19 includes a determination processing unit 51, a first supply processing unit 52, and a second supply processing unit 53.

[0069] Specifically, the ROM 19B of the control unit 19 contains pre-stored operation control programs for enabling the control unit 19 to function as one of the aforementioned processing units. The CPU 19A of the control unit 19 functions as one of the aforementioned processing units by reading and executing the operation control programs from the ROM 19B.

[0070] Furthermore, some or all of the processing units included in the control unit 19 may be composed of electronic circuits. Also, the operation control program may be a program that causes multiple processors to function as the processing units shown in Figure 3.

[0071] The determination processing unit 51 determines whether or not a predetermined supply timing has arrived.

[0072] Specifically, the first condition for determining the supply timing is that the washing process, which includes a washing step, has been completed in the washing machine 1, where the laundry placed in the washing tub 13 (see Figure 2) is washed. In this embodiment, the washing process includes the washing step and a rinsing step for rinsing the laundry.

[0073] Furthermore, the second condition for determining the supply timing is that the water level in the tank 21 is below the reference position.

[0074] Furthermore, the third condition for determining the supply timing is that the pH value of the first alkaline ionized water WA1 in the tank 21 is below a predetermined lower limit.

[0075] Then, if the first and second determination conditions are met, the determination processing unit 51 determines that the supply timing has arrived, regardless of whether the third determination condition is met or not.

[0076] When the determination processing unit 51 determines that the supply timing has arrived, the first supply processing unit 52 causes the ionized water supply unit 30 to supply the second alkaline ionized water WA2 (see Figure 1).

[0077] Specifically, the first supply processing unit 52 causes the ion water supply unit 30 to supply the second alkaline ion water WA2 so that the pH value of the first alkaline ion water WA1 in the tank 21 becomes higher than a predetermined reference value. The reference value is a pH value suitable for washing (for example, 11.0). Note that the reference value may be arbitrarily set according to the user's operation on the operation display unit 18 or the operation display unit 32.

[0078] For example, the first supply processing unit 52 causes the ion water supply unit 30 to supply the second alkaline ion water WA2 until the pH value of the first alkaline ion water WA1 in the tank 21, as detected by the pH sensor 34, reaches a predetermined specific value that is higher than the reference value. For example, the specific value is a pH value that is 1 point higher than the reference value. The specific value may be arbitrarily set according to the user's operation on the operation display unit 18 or the operation display unit 32.

[0079] Furthermore, if the first and third determination conditions are met, but the second determination condition is not met, the control unit 19 will supply the second alkaline ionized water WA2 to the ionized water supply unit 30 so that the pH value of the first alkaline ionized water WA1 in the tank 21 becomes the reference value. In this case, the first supply processing unit 52 and the third supply processing unit 53 will not perform the process of temporarily increasing the pH value of the first alkaline ionized water WA1 in the tank 21.

[0080] The supply timing may also include satisfying the first and third determination conditions.

[0081] Furthermore, the supply timing may be the timing at which a predetermined user operation is received in the operation display unit 18 or the operation display unit 32.

[0082] The second supply processing unit 53, after the supply of the second alkaline ionized water WA2 by the first supply processing unit 52, causes the neutral water supply unit 31 to supply neutral water WA3 (see Figure 1).

[0083] Specifically, the second supply processing unit 53 causes the neutral water supply unit 31 to supply neutral water WA3 so that the pH value of the first alkaline ionized water WA1 in the tank 21 becomes the aforementioned reference value.

[0084] For example, the second supply processing unit 53 causes the neutral water supply unit 31 to supply neutral water WA3 until the pH value of the first alkaline ionized water WA1 in the tank 21, as detected by the pH sensor 34, reaches the reference value.

[0085] Here, when the supply of the second alkaline ionized water WA2 by the first supply processing unit 52 is performed in accordance with the completion of the washing process, the second supply processing unit 53 causes the neutral water supply unit 31 to supply neutral water WA3 in response to the input of the instruction to perform the next washing process.

[0086] As a result, as shown in Figure 6, it is possible to maintain the pH value of the first alkaline ionized water WA1 in the tank 21 at a value higher than the value suitable for washing (the reference value) (the specific value) from the end of the washing process until immediately before the next washing process. In other words, it is possible to improve the disinfecting power of the first alkaline ionized water WA1 during the waiting period while waiting for the instruction to execute the washing process.

[0087] Here, "t0" in Figure 6 indicates the start timing of the washing process. "t1" in Figure 6 indicates the end timing of the washing process and the start timing of the supply process of the second alkaline ionized water WA2 by the first supply processing unit 52. "t2" in Figure 6 indicates the end timing of the supply process of the second alkaline ionized water WA2 by the first supply processing unit 52. "t3" in Figure 6 indicates the input timing of the instruction to execute the next washing process and the start timing of the supply process of neutral water WA3 by the second supply processing unit 53. "t4" in Figure 6 indicates the end timing of the supply process of neutral water WA3 by the second supply processing unit 53. "t5" in Figure 6 indicates the start timing of the next washing process. The period from timing t4 to timing t5 is provided to equalize the pH value of the first alkaline ionized water WA1 in the tank 21.

[0088] Furthermore, the second supply processing unit 53 may cause the neutral water supply unit 31 to supply neutral water WA3 after a predetermined waiting time has elapsed since the first supply processing unit 52 has finished supplying the second alkaline ionized water WA2.

[0089] [Supply Processing] An example of the supply processing procedure performed by the control unit 19 in the washing system 100 will be described below with reference to Figure 5. Here, steps S11, S12... represent the processing procedure (step) numbers performed by the control unit 19.

[0090] <Step S11> First, in step S11, the control unit 19 determines whether or not the supply timing has arrived. The process in step S11 is performed by the determination processing unit 51 of the control unit 19.

[0091] Specifically, when the washing process is completed in the washing machine 1, the control unit 19 determines that the supply timing has arrived based on the water level in the tank 21.

[0092] If the control unit 19 determines that the supply timing has arrived (Yes side of S11), it proceeds to step S12. If the supply timing has not arrived (No side of S11), the control unit 19 waits for the supply timing to arrive in step S11.

[0093] <Step S12> In step S12, the control unit 19 causes the ion water supply unit 30 to supply the second alkaline ion water WA2 (see Figure 1). The process in step S12 is performed by the first supply processing unit 52 of the control unit 19.

[0094] Specifically, the control unit 19 drives the ion water supply pump 30C (see Figure 3) until the pH value of the first alkaline ion water WA1 in the tank 21, as detected by the pH sensor 34, reaches or exceeds the specified value.

[0095] Furthermore, if the second determination condition is not met and the third determination condition is met during the execution of the process in step S11, the control unit 19 drives the ion water supply pump 30C (see Figure 3) until the pH value of the first alkaline ion water WA1 in the tank 21, as detected by the pH sensor 34, reaches the reference value.

[0096] <Step S13> In step S13, the control unit 19 causes the neutral water supply unit 31 to supply neutral water WA3 (see Figure 1). The process in step S13 is performed by the second supply processing unit 53 of the control unit 19.

[0097] Specifically, when the later of the timing between the completion of step S12 and the input of the next washing process is received, the control unit 19 drives the neutral water supply pump 31C (see Figure 3) until the pH value of the first alkaline ionized water WA1 in the tank 21, as detected by the pH sensor 34, reaches the reference value.

[0098] Thus, the washing system 100 includes an ion water supply unit 30 that supplies second alkaline ion water WA2 to the tank 21. This makes it possible to avoid a decrease in the pH value of the first alkaline ion water WA1 in the tank 21, compared to a configuration in which the second alkaline ion water WA2 is supplied to the washing tub 13 of the washing machine 1 (see Figure 2), or to the water channel from the tank 21 to the washing tub 13. In other words, by maintaining the pH value of the first alkaline ion water WA1 in the tank 21 within a predetermined range, the inside of the tank 21 can be disinfected.

[0099] Furthermore, the washing system 100 includes a neutral water supply unit 31 that supplies neutral water WA3 to the tank 21. This makes it possible to replenish the water that is removed from the circulation path R1 by the laundry after washing.

[0100] Furthermore, in the washing system 100, when the supply timing arrives, the second alkaline ionized water WA2 is supplied to the tank 21 first, followed by the supply of neutral water WA3 to the tank 21. This makes it possible to raise the pH value of the first alkaline ionized water WA1 in the tank 21 above the value suitable for washing (the standard value). Therefore, it is possible to enhance the sterilizing power of the first alkaline ionized water WA1 in the tank 21.

[0101] [Modification] The determination processing unit 51, the first supply processing unit 52, and the second supply processing unit 53 may be provided in the water circulation device 2 instead of the washing machine 1. In other words, the water circulation device 2 may be equipped with control units that function as the determination processing unit 51, the first supply processing unit 52, and the second supply processing unit 53.

[0102] Furthermore, the washing system 100 does not necessarily have to include a neutral water supply unit 31 and a second supply processing unit 53. In this case, the replenishment of water (neutral water) to the tank 21 can be done manually. The determination processing unit 51 only needs to determine that the supply timing has arrived when the water level in the tank 21 rises, or when the pH value of the first alkaline ionized water WA1 in the tank 21 falls below the lower limit.

[0103] Furthermore, the shape of the tank 21 is not limited to a roughly rectangular parallelepiped. Also, the positions of the water inlet 21A, drain outlet 21B, first supply port 21C, second supply port 21D, and pH sensor 34 in the tank 21 are not limited to the positions shown in Figure 4.

[0104] Furthermore, washing machine 1 is not limited to so-called drum-type washing machines, but may also be a so-called top-loading washing machine.

[0105] [Addendum to the Invention] The following is an outline of the invention extracted from the above-described embodiments. Note that each configuration and processing function described in the following addendum can be selected and combined as desired.

[0106] <Note 1> A water circulation system comprising: a filter for purifying first alkaline ionized water discharged from the washing tub of a washing machine; a tank for storing the first alkaline ionized water purified by the filter; a path forming unit for forming a circulation path for the first alkaline ionized water passing through the filter, the tank, and the washing tub; and a first supply unit for supplying a specific substance to the tank that increases the pH value of the first alkaline ionized water in the tank.

[0107] <Note 2> The water circulation system described in Note 1, wherein the specified substance includes a second alkaline ionized water having a higher pH value than the first alkaline ionized water.

[0108] <Note 3> The water circulation system according to Note 1 or 2, further comprising a second supply unit for supplying neutral water to the tank.

[0109] <Note 4> The water circulation system according to Note 3, comprising: a first supply processing unit that causes the first supply unit to supply the specified substance when a predetermined supply timing arrives; and a second supply processing unit that causes the second supply unit to supply the neutral water after the first supply processing unit has supplied the specified substance.

[0110] <Note 5> The water circulation system according to Note 4, wherein the supply timing includes the timing at which a washing process, including a washing step for washing the laundry contained in the washing tub of the washing machine, is completed, and the second supply processing unit, upon receiving an input instruction to execute the next washing process, causes the second supply unit to supply the neutral water when the supply of the specific substance by the first supply processing unit is performed in response to the completion of the washing process.

[0111] <Note 6> The water circulation system according to Note 3, wherein the tank is provided with a water inlet at the first end of a pair of horizontally opposing ends of the tank, to which the first alkaline ionized water purified by the filter is supplied, and a drain outlet provided at a second end of the pair of ends different from the first end, which leads to the washing tub along the circulation path.

[0112] <Note 7> The water circulation system according to Note 6, wherein the tank is formed in a substantially rectangular parallelepiped shape, and the pair of ends are two of the four corners of the tank.

[0113] <Note 8> The water circulation system according to Note 7, wherein the tank is provided in one of the four corners other than the first corner and the second corner, and comprises a first supply port for supplying the specified substance, and a second supply port provided in one of the four corners other than the first corner and the second corner, and comprises a second supply port for supplying neutral water.

[0114] <Note 9> The water circulation system according to any one of Notes 6 to 8, further comprising a pH sensor provided at the second end for detecting the pH value of the first alkaline ionized water.

Claims

1. A water circulation system comprising: a filter for purifying first alkaline ionized water discharged from the washing tub of a washing machine; a tank for storing the first alkaline ionized water purified by the filter; a path forming unit for forming a circulation path for the first alkaline ionized water passing through the filter, the tank, and the washing tub; and a first supply unit for supplying a specific substance to the tank that increases the pH value of the first alkaline ionized water in the tank.

2. The water circulation system according to claim 1, wherein the specified substance includes a second alkaline ionized water having a higher pH value than the first alkaline ionized water.

3. The water circulation system according to claim 1 or 2, further comprising a second supply unit for supplying neutral water to the tank.

4. The water circulation system according to claim 3, comprising: a first supply processing unit that causes the first supply unit to supply the specified substance when a predetermined supply timing arrives; and a second supply processing unit that causes the second supply unit to supply the neutral water after the first supply processing unit has supplied the specified substance.

5. The water circulation system according to claim 4, wherein the supply timing includes the timing at which a washing process, including a washing step for washing the laundry contained in the washing tub of the washing machine, is completed, and the second supply processing unit, upon receiving an input instruction to execute the next washing process, causes the second supply unit to supply the neutral water when the supply of the specific substance by the first supply processing unit is performed in response to the completion of the washing process.

6. The water circulation system according to claim 3, wherein the tank is provided with a water inlet at the first end of a pair of horizontally opposing ends of the tank, to which the first alkaline ionized water purified by the filter is supplied, and a drain outlet provided at a second end of the pair of ends different from the first end, which leads to the washing tub along the circulation path.

7. The water circulation system according to claim 6, wherein the tank is formed in a substantially rectangular parallelepiped shape, and the pair of ends are two of the four corners of the tank.

8. The water circulation system according to claim 7, wherein the tank is provided in one of the four corners other than the first corner and the second corner, and has a first supply port for supplying the specific substance, and has a second supply port provided in one of the four corners other than the first corner and the second corner, and has a second supply port for supplying the neutral water.

9. The water circulation system according to claim 6, further comprising a pH sensor provided at the second end for detecting the pH value of the first alkaline ionized water.

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