Water clarification apparatus

Abstract

To provide a water clarification apparatus that can suppress bacteria from breeding in a filtration part 10.SOLUTION: A water clarification apparatus 1 is provided with a filtration part 10 that removes objects to be treated from water to be treated including the objects to be treated, by a filtration material 19 to generate clean water; an ozone generation part 7 that generates ozone gas by electrolyzing water; an ozone water generation part 9 that mixes the ozone gas with the water to be treated or the clean water to generate ozone water; and a control part 3 that controls execution of a filtration mode of generating clean water from the water to treated and a washing mode of washing the filtration material. Before the washing mode is constituted and an ozone water washing mode of supplying ozone water to the filtration part 10 is executed, the control part 3 executes a filtration material expansion mode of expanding the filtration material 19 compressed by supplying the water to be treated to the filtration part 10 from the opposite direction of a supplying direction of the water to be treated in the filtration mode, for more than a given time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a water purification device. [Background technology]

[0002] Physical filtration, which uses activated carbon or sand as a filtering material, has been known as a water treatment method for removing impurities from water. However, in water purification devices using filtering materials, impurities, especially organic matter, tend to accumulate inside the filtering material, so they must be periodically cleaned and the organic matter must be discharged to the outside.

[0003] However, organic matter with small molecular weights is adsorbed into the pores of the filter material, making it difficult to remove even after cleaning. Furthermore, in the case of household water treatment systems, cleaning operations are not performed due to long periods of absence, resulting in the accumulation of organic matter on the filter material for a long period of time. As the accumulation time increases, the adsorbed and accumulated organic matter becomes a nutrient source, causing bacteria such as Legionella to grow and multiply on the filter material, resulting in human infections. Ozone-based decomposition and sterilization methods are known to decompose organic matter contained in the water to be treated or the treated water, and to sterilize the bacteria that have multiplied. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 6-59474 Summary of the Invention [Problem to be solved by the invention]

[0005] The purification treatment system disclosed in Patent Document 1 is capable of decomposing organic matter and sterilizing bacteria by combining an ozone supply / treatment device with a filtration device. However, there is still an unresolved issue that bacteria are likely to grow inside the filtration device if the filtration device is not used frequently, if the flow rate inside the filtration device is low, or if maintenance of the filtration device is neglected.

[0006] Therefore, the present invention solves the above-described conventional problems, and an object thereof is to provide a water purification device capable of suppressing the growth of bacteria in a filtration unit.

Means for Solving the Problems

[0007] And, in order to achieve this object, a water purification device according to the present invention includes a filtration unit that removes a treatment target from treated water containing the treatment target by a filter medium to generate purified water, an ozone generation unit that generates ozone gas by electrolysis of water, an ozone water generation unit that mixes ozone gas with the treated water or purified water to generate ozone water, and a control unit that controls the execution of a filtration mode for generating purified water from the treated water and a cleaning mode for cleaning the filter medium. The control unit executes a filter medium expansion mode in which the treated water is fed to the filtration unit from a direction opposite to the feeding direction of the treated water in the filtration mode for a certain period of time or more to expand the compressed filter medium before executing an ozone water cleaning mode that constitutes the cleaning mode and feeds ozone water to the filtration unit, thereby achieving the intended object.

Effects of the Invention

[0008] According to the present invention, it is possible to provide a water purification device capable of suppressing the growth of bacteria in a filtration unit.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following embodiments are examples of embodying the present invention and do not limit the technical scope of the present invention. Also, each drawing described in the embodiments is a schematic diagram, and the ratio of the size and thickness of each component in each drawing does not necessarily reflect the actual dimensional ratio.

[0011] (Embodiment 1) ((Overall Configuration)) Referring to FIG. 1, the water purification device 1 according to the present embodiment will be described. FIG. 1 is a schematic diagram of the water purification device 1 according to the present embodiment.

[0012] As shown in FIG. 1, the water purification device 1 is water sent from a water purification plant or the like through a water supply pipe 2 or the like, and is a device that purifies the water to be treated containing impurities such as organic substances and bacteria as the object to be treated and makes it usable as domestic water. The water purification device 1 purifies the water to be treated and cleans the filter medium by executing each mode of a filtration mode, a filter medium deployment mode, a water to be treated washing mode, and an ozone water washing mode. Details of each mode will be described later. Note that the filter medium deployment mode, the water to be treated washing mode, and the ozone water washing mode are collectively referred to as the washing mode. The water purification device 1 includes an inlet 21, a control unit 3, an ozone generation unit 7, an ozone water generation unit 9, a filtration unit 10, a measurement unit 20, a purified water discharge port 27, and a backwash discharge port 29.

[0013] The inlet 21 is an opening that introduces the water to be treated pumped from the outside of the water purification device 1 such as a water purification plant through the water supply pipe 2 into the water purification device 1. The inlet 21 is provided in the housing constituting the water purification device 1 and is communicatively connected to an inlet pipe 22 described later.

[0014] The control unit 3 controls the switching of the flow path of the water to be treated flowing through the water purification device 1 in each of the filtration mode, the filter medium deployment mode, the water washing mode of the object to be treated, and the ozone water washing mode. The specific switching of the flow path by the control unit 3 in each mode will be described later. As hardware, the control unit 3 can be realized by elements and mechanical devices including a computer's CPU (Central Processing Unit), and as software, it can be realized by a computer program or the like. Therefore, these functional blocks can be realized in various forms by a combination of hardware and software. The control unit 3 is connected to the ozone generation unit 7, the ozone water generation unit 9, the upstream switching valve 5, the constant flow valve 24, the three-way valve 25, the switching valve 11, and the measurement unit 20 by wire or wirelessly, and controls the operation of each component.

[0015] The ozone generation unit 7 is a device that takes in the water to be treated and generates ozone gas by performing electrolysis with electrodes. The ozone generation unit 7 is communicatively connected to a second water supply pipe 23b, which will be described later, and an ozone water generation unit 9 is provided on the downstream side of the ozone generation unit 7.

[0016] The ozone water generation unit 9 is a device that generates ozone water by mixing the ozone gas generated by the ozone generation unit 7 into the water to be treated. In the ozone water generation unit 9, it is also possible to mix ozone gas into the purified water generated by the filtration unit 10, which will be described later, instead of the water to be treated, to generate ozone water. In this case, piping or the like for supplying the generated purified water to the ozone water generation unit 9 is provided.

[0017] The filtration unit 10 generates purified water by capturing and separating and removing objects to be treated such as organic substances or bacteria contained in the water to be treated with a filter medium 19 provided inside. The filtration unit 10 is communicatively connected to a third water supply pipe 23c, a water guide pipe 15, a purified water discharge pipe 26, and a backwash discharge pipe 28, respectively.

[0018] Above the filtration unit 10 vertically, a switching valve 11 and an opening 13 at one end are provided, and inside the filtration unit 10, a water guide pipe 15 and a filter medium 19 are provided.

[0019] The switching valve 11 is a valve that switches the water supply destination of the water flowing into the filtration unit 10 and the water sent out from the filtration unit 10 according to the operation mode of the water purification device 1. The switching valve 11 is communicably connected to the third water supply pipe 23c, the one-end side opening 13, the water conduit 15, the purified water discharge pipe 26, and the backwash discharge pipe 28 by wireless or wired means, and the water supply destination is switched by a signal from the control unit 3.

[0020] The one-end side opening 13 is an opening that is connectable to the end of the third water supply pipe 23c for water supply by switching the switching valve 11 during the filtration mode, and introduces the water to be treated flowing through the third water supply pipe 23c into the filtration unit 10. Further, the one-end side opening 13 is an opening that is connectable to the end of the backwash discharge pipe 28 for water supply by switching the switching valve 11 during the water to be treated washing mode and the ozone water washing mode, and sends the water in the filtration unit 10 to the backwash discharge pipe 28. The one-end side opening 13 corresponds to the other-end side opening 17 described later, and is provided vertically above the other-end side opening 17.

[0021] The filter medium 19 is a substance that captures substances to be treated such as organic substances or bacteria contained in the water to be treated. As the filter medium 19, for example, activated carbon or filter sand can be used. The filter medium 19 is provided below the filtration unit 10, and there are gaps between the particles of the filter medium 19. The ratio of these gaps is defined as the porosity, and the porosity of the filter medium 19 indicates the ratio of the gaps per unit volume of the filter medium 19 as a percentage. In other words, the porosity is the ratio of the gaps in the occupied portion of the filter medium 19 in the filtration unit 10 (the space 30 from the bottom surface of the filter medium 19 to the upper surface of the filter medium 19). Also, in the filtration unit 10, the filter medium 19 is not filled up to the top surface, and there is a space 31 above the filter medium 19. The interstitial rate of the filtration unit 10 indicates the ratio of the volume of the space 31 above the filter medium 19 to the total volume of the filtration unit 10 as a percentage. Note that the space 31 refers to the non-occupied portion of the filter medium 19 and is the space from the upper surface of the filter medium 19 to the upper surface of the filtration unit 10.

[0022] In the cleaning mode according to this embodiment, since water is supplied to the filtration unit 10 from the side opposite to that in the filtration mode, the filter medium 19 compressed in the filtration mode is expanded. Therefore, by providing the space 31 above the filter medium 19, the filter medium 19 is more easily expanded, and the backwashing efficiency in the cleaning mode is improved. In the cleaning mode, compared with the end of the filtration mode, the porosity of the filter medium 19 increases, and the porosity of the filtration unit 10 decreases.

[0023] The water conduit 15 is provided in the filtration unit 10 and is a pipe connecting from the upper part to the lower part in the filtration unit 10, and the other end side opening 17 is provided at its lower end. By the water conduit 15, in the filtration mode, the water to be treated flowing into the filtration unit 10 is supplied from the upper part to the lower part of the filtration unit 10, and in the filter medium expansion mode, the treated water cleaning mode, and the ozone water cleaning mode, the water used for cleaning the filter medium 19 in the filtration unit 10 is supplied from the lower part of the filtration unit 10 to the upper part of the filtration unit 10 and sent out of the filtration unit 10.

[0024] The other end side opening 17 is buried in the filter medium 19 and is provided vertically below the one end side opening 13. The other end side opening 17 is an opening for supplying the water in the water conduit 15 into the filtration unit 10 or for supplying the water in the filtration unit 10 to the water conduit 15.

[0025] In the water conduit 15, the lower part including the other end side opening 17 is buried in the filter medium 19, while the upper part is not buried in the filter medium 19 and is connected to the switching valve 11. That is, the water conduit 15 is a pipe for supplying the water sent from the switching valve 11 to the filter medium 19 existing in the lower part of the filtration unit 10 or for supplying the water in the filtration unit 10 from the lower part of the filtration unit 10 to the switching valve 11.

[0026] The measurement unit 20 is provided on the purified water discharge pipe 26 described later and is a device for measuring the water quality of the purified water generated by purification in the filtration unit 10. As the measurement unit 20, for example, a COD meter (Chemical Oxygen Demand) can be used.

[0027] The purified water discharge port 27 is an opening for taking out the water to be treated filtered by the water purification device 1 as purified water (treated water) to the outside of the water purification device 1. The purified water discharge port 27 is provided in the housing constituting the water purification device 1 and is communicatively connected to the purified water discharge pipe 26 described later.

[0028] The backwash discharge port 29 is an opening for discharging the water to be treated or ozone water used for cleaning the filtration unit 1 to the outside of the water purification device 1. The backwash discharge port 29 is an opening provided in the housing constituting the water purification device 1 and is communicatively connected to the backwash discharge pipe 28.

[0029] ((Flow Path and Valve)) The flow path of the water purification device 1 is constituted by an inflow pipe 22, a first water supply pipe 23a, a second water supply pipe 23b, a third water supply pipe 23c, a purified water discharge pipe 26, and a backwash discharge pipe 28.

[0030] The inflow pipe 22 is communicatively connected to the inlet 21 and the upstream switching valve 5, and is a pipe for supplying the water to be treated taken into the water purification device 1 from the inlet 21 to the upstream switching valve 5.

[0031] The upstream switching valve 5 is a valve for switching the water supply destination so that water is supplied from the inflow pipe 22 to either the first water supply pipe 23a or the second water supply pipe 23b. As the upstream switching valve 5, for example, a three-way electric valve can be used. The upstream switching valve 5 is communicatively connected to the control unit 3 wirelessly or by wire, and the water supply destination is switched by a signal from the control unit 3.

[0032] From the upstream switching valve 5 to the filtration unit 10, it is connected by the first water supply pipe 23a, the second water supply pipe 23b, and the third water supply pipe 23c.

[0033] The first water supply pipe 23a is a pipe that communicatively connects from the upstream switching valve 5 to a branch point B described later, and is used in the filtration mode, the filter medium deployment mode, and the water to be treated cleaning mode.

[0034] The second water supply pipe 23b is a pipe that communicatively connects from the upstream switching valve 5 to a branch point B, which will be described later, and is used in the ozone water washing mode. A constant flow rate valve 24, an ozone generation unit 7, and an ozone water generation unit 9 are provided on the second water supply pipe 23b.

[0035] The constant flow rate valve 24 is a valve that stabilizes the flow rate of the water to be treated sent to the ozone generation unit 7 during operation in the ozone water washing mode at a constant flow rate, and is communicatively connected to the second water supply pipe 23b.

[0036] The third water supply pipe 23c is a pipe that communicatively connects from a branch point B, which will be described later, to one end opening 13 of the filtration unit 10, and is used in the filtration mode, the filter medium deployment mode, the water to be treated washing mode, and the ozone water washing mode.

[0037] The downstream end of the inflow pipe 22, the upstream end of the first water supply pipe 23a, and the upstream end of the second water supply pipe 23b are respectively connected, and the connection point is the branch point A. An upstream switching valve 5 is provided on the branch point A. The upstream switching valve 5 is provided.

[0038] The downstream end of the first water supply pipe 23a, the downstream end of the second water supply pipe 23b, and the upstream end of the third water supply pipe 23c are respectively connected, and the connection point is the branch point B. A three-way valve 25 is provided on the branch point B.

[0039] The three-way valve 25 is a valve that switches the water supply source so that water is supplied from either the first water supply pipe 23a or the second water supply pipe 23b to the third water supply pipe 23c. The three-way valve 25 is communicatively connected to the control unit 3 wirelessly or by wire, and the water supply destination is switched by a signal from the control unit 3.

[0040] The purified water discharge pipe 26 is communicatively connected to the switching valve 11 and the purified water discharge port 27, and is a pipe that sends the water to be treated from which organic substances, bacteria, etc. have been removed by the filtration unit 10 to the purified water discharge port 27. A measurement unit 20 is provided on the purified water discharge pipe 26.

[0041] The backwash discharge pipe 28 is communicatively connected to the switching valve 11 and the backwash discharge port 29, and is a pipe for sending the water to be treated or ozone water used for cleaning the filtration unit 10 to the backwash discharge port 29.

[0042] The above is the configuration of the water purification device 1.

[0043] Next, the operation of the water purification device 1 will be described.

[0044] First, with reference to FIG. 2, the operation in the filtration mode by the water purification device 1 will be described. FIG. 2 is a schematic diagram in the filtration mode according to the present embodiment.

[0045] In the water purification device 1, in the filtration mode, under the control of the control unit 3, the upstream switching valve 5 is in a state of communicating the inflow pipe 22 and the first water supply pipe 23a, the three-way valve 25 is in a state of communicating the first water supply pipe 23a and the third water supply pipe 23c, and the switching valve 11 is in a state of communicating the third water supply pipe 23c and the one-end side opening 13. As a result, the water to be treated containing impurities flows into the water purification device 1 from the outside, and flows in the order of the inlet 21, the inflow pipe 22, the upstream switching valve 5, the first water supply pipe 23a, the three-way valve 25, the third water supply pipe 23c, and the switching valve 11. In other words, the purification flow path is formed by the inflow pipe 22, the first water supply pipe 23a, the third water supply pipe 23c, and the switching valve 11, and the water to be treated flows through the purification flow path. The water to be treated that has passed through the switching valve 11 flows into the filtration unit 10 from the one-end side opening 13 and flows through the filter medium 19 provided in the filtration unit 10. At this time, the impurities in the water to be treated are adsorbed by the filter medium 19, and the water to be treated is filtered. Since the water to be treated flows into the filtration unit 10 from above the filtration unit 10, the filter medium 19 is gradually compressed by the water to be treated as time passes in the filtration mode. As a result, at the end of the filtration mode, compared with the start of the filtration mode, the porosity of the filter medium 19 decreases (for example, decreases by 20% from the start of the filtration mode), and the porosity of the filtration unit 10 increases (for example, increases by 10% from the start of the filtration mode). The purified water generated by filtering the water to be treated flows through the purified water discharge pipe 26 and is sent out of the water purification device 1 from the purified water discharge port 27. Note that the porosity of the filter medium 19 at the start of the filtration mode is, for example, 40%, and the porosity of the filtration unit 10 is, for example, 20%.

[0046] When the execution time of the filtration mode exceeds a certain time (for example, 10 hours), the control unit 3 ends the filtration mode and executes the filter medium deployment mode.

[0047] Next, with reference to FIG. 3, the operation of the water purification apparatus 1 in the filter medium deployment mode will be described. FIG. 3 is a schematic diagram of the filter medium deployment mode according to the present embodiment.

[0048] In the water purification apparatus 1, in the filter medium deployment mode, under the control of the control unit 3, the upstream switching valve 5 is in a state of communicating the inflow pipe 22 and the first water supply pipe 23a, the three-way valve 25 is in a state of communicating the first water supply pipe 23a and the third water supply pipe 23c, and the switching valve 11 is in a state of communicating the third water supply pipe 23c and the water guide pipe 15. As a result, the water to be treated flows into the water purification apparatus 1 from the outside, and flows through the inlet 21, the inflow pipe 22, the upstream switching valve 5, the first water supply pipe 23a, the three-way valve 25, the third water supply pipe 23c, the switching valve 11, and the water guide pipe 15 in this order. In other words, the cleaning flow path is formed by the inflow pipe 22, the first water supply pipe 23a, the third water supply pipe 23c, and the water guide pipe 15, and the water to be treated flows through the cleaning flow path. The water to be treated that has flowed through the water guide pipe 15 flows into the filter unit 10 from the other end side opening 17 of the filter unit 10 and flows through the filter medium 19 provided in the filter unit 10. That is, it flows into the filter unit 10 from the end opposite to that in the filtration mode. The inflowing water to be treated removes the substances to be treated adsorbed between the holes of the filter medium 19 and between the filter media 19 by passing through the holes of the filter medium 19 and between the filter media 19. At this time, since the filter medium 19 compressed in the filtration mode is expanded by the flow velocity of the water to be treated, the porosity of the filter medium 19 increases (for example, increases by 20% from the end of the filtration mode), and the porosity of the filter unit 10 decreases (for example, decreases by 10% from the end of the filtration mode) compared with the end of the filtration mode. In this way, the water to be treated flowing in from the lower part of the filter unit 10 is sent to the upper part of the filter unit 10 while washing the internal filter medium 19, and is sent to the backwash discharge pipe 28 via the switching valve 11. Thereafter, the water to be treated flows through the backwash discharge pipe 28 and is drained out of the water purification apparatus 1 from the backwash discharge port 29.

[0049] When the execution time of the filter medium deployment mode exceeds a certain time (e.g., 2 minutes), the control unit 3 ends the filter medium deployment mode and executes the ozone water washing mode. The certain time in the filter medium deployment mode is the shorter of the time from the start of the filter medium deployment mode until the porosity of the filtration unit 10 reaches the porosity before the start of the filtration mode, or the time when the porosity increases by 20% or more based on the porosity of the filter medium 19 at the end of the filtration mode. Specifically, when the volume compression of the filter medium 19 in the filtration mode is small, the deployment rate of the filter medium 19 may be small, so the filter medium deployment mode may be performed until the porosity before the start of the filtration mode is reached. On the other hand, when the volume compression of the filter medium 19 in the filtration mode is large, it takes time to make the porosity of the filtration unit 10 the same as the porosity before the start of the filtration mode, and the drainage volume of the water to be treated also increases. Therefore, the filter medium deployment mode may be performed until the porosity increases by 20% or more based on the porosity of the filter medium 19 at the end of the filtration mode. Here, 20% is based on the viewpoints of relaxation of the volume compression of the filter medium 19, the cleaning effect in the ozone water washing mode executed after the filter medium deployment mode, and the drainage volume in the filter medium deployment mode.

[0050] Next, with reference to FIG. 4, the operation of the water purification device 1 in the ozone water washing mode will be described. FIG. 4 is a schematic diagram in the ozone water washing mode according to the present embodiment.

[0051] In the water purification device 1, in the ozone water washing mode, under the control of the control unit 3, the upstream switching valve 5 is in a state of communicating the inflow pipe 22 and the second water supply pipe 23b, the three-way valve 25 is in a state of communicating the second water supply pipe 23b and the third water supply pipe 23c, and the switching valve 11 is in a state of communicating the third water supply pipe 23c and the water guide pipe 15. As a result, the water to be treated flows into the water purification device 1 from the outside, passes through the inlet 21, the inflow pipe 22, the upstream switching valve 5, the second water supply pipe 23b, and the constant flow valve 24, and flows into the ozone generation unit 7. The water to be treated flowing into the ozone generation unit 7 is electrolyzed by a pair of electrodes (anode and cathode) provided inside the ozone generation unit 7, and ozone gas is generated by this electrolysis. The water to be treated containing ozone gas flows into the ozone water generation unit 9, and the ozone gas dissolves in the water to be treated, resulting in ozone water containing ozone. The ozone water generated in the ozone water generation unit 9 flows in the order of the three-way valve 25, the third water supply pipe 23c, the switching valve 11, and the water guide pipe 15. The ozone water flowing through the water guide pipe 15 flows into the filtration unit 10 from the other end opening 17 of the filtration unit 10 and passes through the filter medium 19 provided in the filtration unit 10. That is, the ozone water flows into the filtration unit 10 from the end opposite to that in the filtration mode. In other words, the reverse washing of the filtration unit 10 is performed by the ozone water. The flow rate of the inflowing ozone water is a value smaller than the flow rate of the water to be treated in the filter medium deployment mode (for example, a flow rate of 80% of the flow rate in the filter medium deployment mode ). The inflowing ozone water passes through the pores of the filter medium 19 and between the filter media 19 to remove the substances to be treated adsorbed in the pores of the filter medium 19 and between the filter media 19 and perform sterilization by ozone. At this time, the ozone water flows in the filtration unit 10 in the direction opposite to the filtration mode, and the filter medium 19 is expanded by the flow rate of the ozone water. Therefore, compared with the end of the filtration mode, the porosity of the filter medium 19 increases (for example, increases by 10% from the end of the filtration mode), and the porosity of the filtration unit 10 decreases (for example, decreases by 5% from the end of the filtration mode). In this way, the ozone water flowing in from the lower part of the filtration unit 10 is sent to the upper part of the filtration unit 10 while washing the internal filter medium 19, and is sent to the reverse washing discharge pipe 28 through the switching valve 11. Then, the ozone water flows through the reverse washing discharge pipe 28 and is drained out of the water purification device 1 from the reverse washing discharge port 29.

[0052] When the execution time of the ozone water washing mode exceeds a certain time (for example, 2 minutes), the control unit 3 ends the ozone water washing mode and executes the water to be treated washing mode.

[0053] Next, with reference to FIG. 3, the operation during the water to be treated washing mode by the water purification device 1 will be described. FIG. 3 is a schematic diagram during the water to be treated washing mode according to the present embodiment.

[0054] In the water purification device 1, in the mode of washing the water to be treated, under the control of the control unit 3, the upstream switching valve 5 is in a state of communicating the inflow pipe 22 with the first water supply pipe 23a, the three-way valve 25 is in a state of communicating the first water supply pipe 23a with the third water supply pipe 23c, and the switching valve 11 is in a state of communicating the third water supply pipe 23c with the water guide pipe 15. As a result, the water to be treated flows into the water purification device 1 from the outside, and flows through the inlet 21, the inflow pipe 22, the upstream switching valve 5, the first water supply pipe 23a, the three-way valve 25, the third water supply pipe 23c, the switching valve 11, and the water guide pipe 15 in this order. In other words, the washing flow path is formed by the inflow pipe 22, the first water supply pipe 23a, the third water supply pipe 23c, and the water guide pipe 15, and the water to be treated flows through the washing flow path. The water to be treated that has flowed through the water guide pipe 15 flows into the filtration unit 10 from the other end side opening 17 of the filtration unit 10 and flows through the filter medium 19 provided in the filtration unit 10. That is, the water to be treated flows into the filtration unit 10 from the end on the opposite side to that in the filtration mode. In other words, the backwashing of the filtration unit 10 is performed by the water to be treated. The flow rate of the inflowing water to be treated is a value larger than the flow rate of the ozone water in the ozone water washing mode (for example, a flow rate of 120% of the flow rate in the ozone water washing mode). The inflowing water to be treated passes through the holes of the filter medium 19 and between the filter media 19 to remove the substances to be treated adsorbed to the holes of the filter medium 19 and between the filter media 19. At this time, since the filter medium 19 is expanded by the flow rate of the water to be treated, the porosity of the filter medium 19 increases (for example, increases by 20% from the end of the ozone water washing mode), and the porosity of the filtration unit 10 decreases (for example, decreases by 10% from the end of the ozone water washing mode) as compared with the ozone water washing mode. In this way, the water to be treated flowing in from the lower part of the filtration unit 10 is sent to the upper part of the filtration unit 10 while washing the internal filter medium 19, and is sent to the backwashing discharge pipe 28 through the switching valve 11. Thereafter, the water to be treated flows through the backwashing discharge pipe 28 and is drained out of the water purification device 1 from the backwashing discharge port 29.

[0055] When the execution time of the mode of washing the water to be treated exceeds a certain time (for example, 2 minutes), the control unit 3 ends the mode of washing the water to be treated and enters a standby state of executing the filtration mode or waiting to execute the filtration mode.

[0056] As described above, in the water purification device 1, the filtration mode, the filter medium deployment mode, the ozone water washing mode, and the water to be treated washing mode are repeatedly executed. In other words, the generation of purified water by the filtration unit 10 and the regeneration of the filtration unit 10 are repeatedly executed.

[0057] In the operation of the water purification device 1, in many cases, the total water flow rate of the water to be treated or ozone water to the filtration unit 10 in the filter medium deployment mode, the water to be treated washing mode, and the ozone water washing mode is less than the water flow rate of the water to be treated to the filtration unit 10 in the filtration mode. In other words, the water flow rate to the filtration unit 10 during the regeneration of the filter medium 19 is less than the water flow rate to the filtration unit 1 0 during the generation of purified water. However, depending on the usage environment of the water purification device 1, there may be a case where the water flow rate to the filtration unit 10 in the filtration mode is equal to or greater than the total water flow rate to the filtration unit 10 in the filter medium deployment mode, the water to be treated washing mode, and the ozone water washing mode. Also, the ozone water washing mode is executed so that the total water flow rate of ozone water to the filtration unit 10 in the ozone water washing mode is at least the same volume as the volume of the filter medium 19.

[0058] As described above, according to the water purification device 1 according to the present embodiment, the following effects can be enjoyed.

[0059] (1) The water purification device 1 includes a filtration unit 10 that removes contaminants from the water to be treated containing contaminants by the filter medium 19 to generate purified water, an ozone generation unit 7 that generates ozone gas by electrolysis of water, an ozone water generation unit that mixes ozone gas with the water to be treated or purified water to generate ozone water, and a control unit 3 that supplies ozone water to the filtration unit 10 when washing the filter medium 19. According to such a configuration, when the filtration unit 10 is backwashed, it can be washed with ozone water, which is washing water containing ozone, to decompose organic substances accumulated in the filter medium 19 and perform disinfection.

[0060] (2) In the water purification device 1, the control unit 3 feeds the water to be treated to the filtration unit 10 before feeding the ozone water. As a result, the compressed filter medium 19 can be expanded in the filtration mode, and the filter medium 19 can be easily washed by the ozone water in the ozone water washing mode. Further, after discharging the object to be treated accumulated on the filter medium 19 outside the water purification device with the water to be treated, the filtration unit 10 can be washed with the ozone water. Furthermore, the influence of the object to be treated accumulated on the filter medium 19 can be suppressed, and the filter medium 19 can be washed with the ozone water. Therefore, it becomes possible to efficiently decompose organic substances and sterilize.

[0061] (3) In the water purification device 1, the control unit 3 feeds the ozone water in the ozone water washing mode at a value smaller than the flow rate of the water to be treated in the filter medium expansion mode. As a result, after the filter medium 19 is expanded, the filtration unit 10 can be washed with the ozone water. Further, by reducing the flow rate, the ozone concentration in the ozone water can be increased. Therefore, washing with high-concentration ozone water becomes possible, and it becomes possible to efficiently decompose organic substances and sterilize. Furthermore, it becomes possible to enhance the sterilization effect.

[0062] (4) In the water purification device 1, the control unit 3 feeds the water to be treated in the water to be treated washing mode at a value larger than the flow rate of the ozone water in the ozone water washing mode. By increasing the flow rate, the filter medium 19 can be expanded again, so that the decomposition products of the organic substances generated in the ozone water washing mode can be discharged outside the water purification device 1. In addition, since the residual ozone water in the filtration unit 10 can be suppressed, it is possible to obtain purified water that can suppress the occurrence of health hazards due to ozone.

[0063] As described above, the embodiments of the present invention have been described based on the embodiments. These embodiments are examples, and it is understood by those skilled in the art that various modifications are possible for each of these constituent elements or combinations of each processing process, and such modifications are also within the scope of the present invention.

[0064] In the first embodiment, the ozone water generation unit 9 is provided on the downstream side of the ozone generation unit 7, but the present invention is not limited to this. For example, a housing integrating the ozone generation unit 7 and the ozone water generation unit 9 may be provided. Inside the housing, a plate-shaped anode, a plate-shaped cathode, and a conductive membrane provided between the anode and the cathode are provided from the upstream side to the downstream side. In this case, the water to be treated is allowed to flow into the housing, and the water to be treated is electrolyzed by the anode and the cathode. Then, in the housing, the ozone gas generated by the electrolysis of the water to be treated on the upstream side is immediately mixed with the water to be treated as soon as it is generated. As a result, ozone water with an increasing ozone gas content can be generated toward the downstream side of the housing. Concentrated ozone water with an increased ozone gas concentration can be generated.

[0065] In the first embodiment, for the filter medium deployment mode, the ozone water cleaning mode, and the water to be treated cleaning mode, the magnitude relationship of the flow rates in each mode is defined. However, for example, it may be defined using the flow rate. Even in this case, the magnitude relationship is the same as the magnitude relationship defined between each mode in the first embodiment.

[0066] In the first embodiment, for the filter medium deployment mode, the ozone water cleaning mode, and the water to be treated cleaning mode, the time for each mode is defined. However, this is merely an example, and for example, times different from the exemplified times may be defined. This is because the time required to obtain the effects in each mode varies depending on the shape of the filter unit 10, the type of the filter medium 19, the flow rate in each mode, and the like.

Industrial Applicability

[0067] The water purification device according to the present invention can be applied to a point-of-use (POU) water purification device installed at the place of use or a point-of-entry (POE) water purification device installed at the building entrance.

Explanation of Reference Numerals

[0068] 1 Water purification device 2 Water supply pipe 3 Control unit 5 Upstream switching valve 7 Ozone generation section 9 Ozone water generation section 10 Filtration section 11 Switching valve 13 One - end opening 15 Water conduit 17 Other - end opening 19 Filter medium 20 Measuring section 21 Inlet 22 Inlet pipe 23a First water supply pipe 23b Second water supply pipe 23c Third water supply pipe 24 Constant - flow valve 25 Three - way valve 26 Purified water discharge pipe 27 Purified water discharge port 28 Backwash discharge pipe 29 Backwash discharge port 30 Space 31 Space A Branch point B Branch point

Claims

1. A filtration unit that removes the object to be treated from the water to be treated containing the object to be treated by a filter medium to generate purified water; An ozone generation unit that generates ozone gas by electrolysis of water; An ozone water generation unit that mixes the ozone gas into the water to be treated or the purified water to generate ozone water; A control unit that controls the execution of a filtration mode for generating the purified water from the water to be treated and a cleaning mode for cleaning the filter medium, comprising: The control unit: Before executing an ozone water cleaning mode that constitutes the cleaning mode and supplies the ozone water to the filtration unit, the water to be treated is supplied to the filtration unit from a direction opposite to the water supply direction of the water to be treated in the filtration mode to expand the compressed filter medium, and a water purification device that executes a filter medium expansion mode for a certain period of time or more.

2. The certain period of time is: The time from the start of the filter medium expansion mode until the porosity of the filtration unit reaches the porosity before the start of the filtration mode, or among the times when the porosity of the occupied portion of the filter medium at the end of the filtration mode increases by 20% or more based on the porosity, the shorter time. The water purification device according to Claim 1.

3. The control unit: After executing the ozone water cleaning mode, the water purification device according to Claim 1, which executes a water to be treated cleaning mode that constitutes the cleaning mode and supplies the water to be treated to the filtration unit.

4. The flow rate of the ozone water in the ozone water cleaning mode is a value smaller than the flow rate of the water to be treated in the filter medium expansion mode. The water purification device according to Claim 1.

5. The control unit: After executing the ozone water cleaning mode, a water to be treated cleaning mode of supplying the water to be treated to the filtration unit from the opposite direction is executed, The flow rate of the water to be treated in the water to be treated cleaning mode is a value larger than the flow rate of the ozone water in the ozone water cleaning mode. The water purification device according to Claim 4.

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