Water treatment device

Abstract

To provide a water treatment device that can suppress leakage risk and unnecessary back washing of a filter medium.SOLUTION: A water treatment device 1 comprises: a filtration tank 13 having a filter medium 23 which removes removal object components from water, and an intermediate water inlet 24 which collects treatment water treated by the filter medium 23 on a center side of a stack height of the filter medium 23; a reverse washing pump 17 which reversely flows treatment water to the filter medium 23 and performs washing; an automatic water quality monitoring device 18 which is connected to the intermediate water inlet 24, and monitors water quality of treatment water collected from the intermediate water inlet 24; and a controller 20 which controls the reverse washing pump 17 and performs reverse washing of the filter medium 23 when water quality of treatment water monitored by the automatic water quality monitoring device 18 is a prescribed water quality that is determined as leakage of removal object components.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a water treatment device that filters water in a filter tank. [Background technology]

[0002] Water treatment devices have been known for some time that remove solid particles such as sand from raw water and target components such as iron and manganese from water. These water treatment devices inject a chemical solution into the raw water and remove the solid particles and target components in a filtration tank. The filter material used in these filtration tanks deteriorates with use. For this reason, water treatment devices perform a so-called backwashing process, in which treated water from the filtration tank is backflowed to clean the filter material.

[0003] For example, it is known that such backwashing is performed periodically using a timer or the like. However, the backwashing process wears and deteriorates the filter material. In addition, treated water is often used for backwashing, and the more frequently backwashing processes are performed, the more treated water is used. This increases the amount of treated water used for backwashing, which puts a strain on the actual use of treated water. Therefore, the fewer times backwashing is performed, the more economical it is.

[0004] Therefore, methods for determining the timing of backwashing other than periodic backwashing include predicting the timing from raw water quality data and the expected amount of water used, determining the timing of backwashing by monitoring the differential pressure between the primary and secondary sides of the filter tank, installing a monitoring device for the components to be removed on the secondary side of the filter tank and determining the timing of backwashing from the monitoring results, and monitoring the concentration of the components to be removed in the raw water and the amount of treated water on the primary side of the filter tank.

[0005] Furthermore, a technology is known for a filter tank used in such a water treatment device, in which an intermediate water intake port is provided at a position higher than the bottom end of the filter material, and the deterioration of the filter material is determined based on the water taken from this intermediate water intake port, and the time for replacement is predicted (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-023953 Summary of the Invention [Problem to be solved by the invention]

[0007] When determining the timing of backwashing based on raw water quality data and expected water usage, backwashing can be performed at specific times, such as once a day, by predicting water usage, or by monitoring the actual amount of filtered water and triggering backwashing when a certain amount of water is filtered. However, this method carries the risk of the components being removed leaking to the secondary side if there is a sudden change in water usage or water quality. Furthermore, there is a risk of backwashing being performed more than necessary when the amount of water usage is low.

[0008] In the method of determining the timing of backwashing by monitoring the differential pressure between the primary and secondary sides of the filter tank, backwashing is performed when the differential pressure exceeds a threshold, but this method has the problem that it cannot be applied when the components removed by the filter material are not affected by the differential pressure, such as manganese.

[0009] In the method of installing a monitoring device for the components to be removed on the secondary side of the filtration tank and determining the timing of backwashing based on the monitoring results, an additional removal device must be installed on the secondary side to prevent leaks, which increases manufacturing and running costs and is not economical.

[0010] In the method of monitoring the concentration of the target components in the raw water and the amount of treated water on the upstream side of the filtration tank, there is a risk of an increased risk of leaks due to deterioration or leakage of the filter material.

[0011] Therefore, an object of the present invention is to provide a water treatment device that can reduce the risk of leaks and unnecessary backwashing of the filter material. [Means for solving the problem]

[0012] According to one aspect of the present invention, a water treatment device includes a filter material that removes components to be removed from raw water, a filter tank having an intermediate water intake port at the center of the stack height of the filter material for sampling treated water treated with the filter material, a backwash pump that backflows the treated water into the filter material to clean it, an automatic water quality monitoring device connected to the intermediate water intake port and monitoring the water quality of the treated water sampled from the intermediate water intake port, and a control device that controls the backwash pump to perform backwashing of the filter material when the water quality of the treated water monitored by the automatic water quality monitoring device is a predetermined water quality that is determined to be a leak of the components to be removed. [Effects of the Invention]

[0013] The present invention can provide a water treatment device that can reduce the risk of leakage and prevent unnecessary backwashing of the filter material. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is an explanatory diagram illustrating a schematic configuration of a water treatment device according to an embodiment of the present invention; [Figure 2] FIG. 2 is an explanatory diagram schematically illustrating the configuration of a filtration tank used in the water treatment device. [Figure 3] FIG. 10 is an explanatory diagram showing an example of information used in the backwashing process. [Figure 4] FIG. [Figure 5] FIG. 10 is an explanatory view showing another example of the backwashing process. [Figure 6] FIG. 10 is an explanatory view showing another example of the backwashing process. [Figure 7] 4 is a flow chart showing an example of a method for determining the backwashing treatment of the water treatment device. [Figure 8] FIG. 10 is an explanatory diagram showing an example of a backwashing process in a water treatment device according to a comparative example. [Figure 9] FIG. 10 is an explanatory diagram showing another example of the backwashing process of the water treatment device according to the comparative example. [Figure 10] FIG. 10 is an explanatory diagram showing another example of the backwashing process of the water treatment device according to the comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0015] The configuration of a water treatment device 1 according to one embodiment of the present invention will be described below with reference to FIGS. 1 to 7. FIG. 1 is an explanatory diagram that schematically shows the configuration of the water treatment device 1, and FIG. 2 is an explanatory diagram that schematically shows the configuration of a filtration tank 13 used in the water treatment device 1. FIG. 3 is an explanatory diagram that shows an example of information used in the backwashing process described in FIGS. 4 to 6. FIG. 4 is an explanatory diagram that shows an example of the backwashing process, FIG. 5 is an explanatory diagram that shows another example of the backwashing process, and FIG. 6 is an explanatory diagram that shows another example of the backwashing process. FIG. 7 is a flow chart that shows an example of a method for determining the backwashing process of the water treatment device 1.

[0016] As shown in Figure 1, water treatment device 1 pumps raw water from a raw water supply source 100 such as a well, and treats the raw water in a filtration tank 13. Here, the treatment of raw water in filtration tank 13 is performed by passing the raw water through a filter material 23 provided in filtration tank 13. The treatment of raw water in filtration tank 13 can be performed in various ways, such as a process of filtering out iron and manganese by precipitating iron and manganese in the raw water by supplying sodium hypochlorite or the like to the raw water, or a process of filtering out impurities such as solid particles such as sand in the raw water.

[0017] As a specific example, the water treatment device 1 includes a pump 11, a first switching valve 12, a filtration tank 13, a second switching valve 14, a water storage tank 15, a water level detector 16, a backwash pump 17, an automatic water quality monitoring device 18, piping 19, and a control panel 20. The water treatment device 1 may also include a sand strainer, a chemical injection device, etc.

[0018] The pump 11 pumps raw water from a supply source 100 on the primary side to the secondary side.

[0019] The first switching valve 12 is connected to the pump 11, the filtration tank 13, and a drain that is a drain destination. The first switching valve 12 is, for example, a three-way valve. The first switching valve 12 is configured to be switchable between connecting the pump 11 and the filtration tank 13 and connecting the filtration tank 13 and the drain, based on a command signal from the control panel 20.

[0020] 2, the filtration tank 13 includes a cylindrical tank body 21, a filter 22 provided at the bottom of the tank body 21, a filter material 23 provided at a predetermined stack height H1 within the tank body 21, and an intermediate water intake port 24 provided at height position H2, which is the center of the stack height H1 in the height direction of the tank body 21. The filtration tank 13 also includes gravel 25 at the bottom of the tank body 21.

[0021] The tank body 21 is formed in a closed cylindrical shape. The tank body 21 has, for example, multiple legs 21a and is installed upright on an installation surface. The tank body 21 is formed in a cylindrical shape having, for example, a bottom 21b, a body 21c, and a ceiling 21d. A layer of gravel 25 piled up to a predetermined height is arranged on the bottom 21b of the tank body 21, and a filter 22 is provided to which a fourth pipe 19d (described later) of the piping 19 is connected. The fourth pipe 19d is also inserted into the bottom 21b. A third pipe 19c (described later) of the piping 19 is connected to the body 21c on the ceiling 21d side of the tank body 21. For example, the third pipe 19c extends radially from the body 21c and bends upward by 90° near the axial center of the body 21c, with its tip opening facing the ceiling 21d at a predetermined distance.

[0022] The filter 22 is formed by a wall portion having a mesh, slits, or fine through-holes, and restricts the movement of gravel 25, solid particles, and filtering material 23 to the secondary side.

[0023] The filter material 23 is provided within the body 21c. The filter material 23 is filled and held within the body 21c to a predetermined height on top of a layer of gravel 25. The filter material 23 is formed, for example, by stacking granular filters to a predetermined height. For example, the filter material 23 captures and removes target components in the raw water by contacting the raw water. For example, the filter material 23 captures iron and / or manganese components, as well as solid particles such as sand, in the raw water. In this embodiment, the filter material 23 will be described below using an example of capturing and removing iron, which is an example of a target component. The filter material 23 is provided within the tank body 21 to a predetermined height H1 (hereinafter referred to as the height of the filter material 23). Here, the height of the filter material 23 refers to the stack height from the bottom to the top of the filter material 23 provided within the tank body 21.

[0024] The intermediate water inlet 24 is formed so that treated water passing through the filter media 23 of the tank main body 21 can be sampled. The intermediate water inlet 24 is provided in the body 21c at a height position that is higher than the lower end of the filter media 23 and lower than the upper end of the filter media 23. The height position H2 of the intermediate water inlet 24 is, for example, at a height lower than the center (H1 / 2) of the stack height H1 of the filter media 23 and at a height higher than the center (H1 / 4) of the position halfway up the stack height H1 from the lower end of the filter media 23 (H1 / 4≦H2≦H1 / 2). The intermediate water inlet 24 is fixed to the body 21c at height position H2 from the lower end of the filter media 23 and is formed so that raw water passing through the filter media 23 can be sampled.

[0025] The second switching valve 14 is connected to the filtration tank 13, the water storage tank 15, and the backwash pump 17. The second switching valve 14 is, for example, a three-way valve. The second switching valve 14 is configured to be switchable between connecting the filtration tank 13 and the water storage tank 15 and connecting the filtration tank 13 and the backwash pump 17 in response to a command signal from the control panel 20.

[0026] The water storage tank 15 is configured to be able to store treated water that has been treated in the filtration tank 13. The water storage tank 15 is connected to a supply destination of the treated water, for example, via a pump device or the like. Note that the water treatment device 1 may be configured not to have the water storage tank 15, and to connect the treated water directly to the supply destination.

[0027] The water level detector 16 detects the water level of the water tank 15. For example, the water level detector 16 detects the driving water level of the pump 11 and the stopping water level of the pump 11. The water level detector 16 outputs a signal corresponding to the detected water level to the control panel 20. The water level detector 16 may be configured to output an ON signal when the driving water level is reached and to stop outputting the signal when the stopping water level is reached. For example, the water level detector 16 is a float switch. The water level detector 16 may be configured to be able to detect multiple water levels including the driving water level and the stopping water level, and an example of a water level detector 16 configured in this way is a water level sensor having multiple electrode rods.

[0028] The backwash pump 17 sends treated water from the water storage tank 15 on the primary side to the second switching valve 14 on the secondary side, and supplies the treated water to the filtration tank 13.

[0029] The automatic water quality monitoring device 18 detects water quality based on the concentration of components, such as the content of components to be removed by the filter media 23, in the raw water, and outputs the detected information to the control panel 20. As a specific example, the automatic water quality monitoring device 18 is connected to the intermediate water intake port 24, monitors the content (concentration) of components to be removed in the treated water that is sampled from the intermediate water intake port 24 and has passed partway through the filter media 23, and outputs the acquired information to the control panel 20. The automatic water quality monitoring device 18 detects the components to be removed, such as iron and manganese, as well as turbidity and hardness, using methods such as absorption spectrometry, spectroscopic analysis, and laser diffraction.

[0030] The piping 19 fluidly connects the various components and forms a flow path through which water flows. As a specific example, the piping 19 includes a first piping 19a connecting the supply source 100 and the pump 11, a second piping 19b connecting the pump 11 and the first switching valve 12, a fourth piping 19d connecting the filtration tank 13 and the second switching valve 14, a fifth piping 19e connecting the second switching valve 14 and the water tank 15, a sixth piping 19f connecting the water tank 15 and the backwash pump 17, a seventh piping 19g connecting the backwash pump 17 and the second switching valve 14, and an eighth piping 19h connecting the first switching valve 12 and a drain.

[0031] The piping 19 fluidly connects the various components to form a first flow path that treats raw water and stores it in the water tank 15, and a second flow path that passes the treated water through the filtration tank 13 for backwashing. As a specific example, the first flow path is a flow path that connects, in the water flow direction, the supply source 100, the pump 11, the first switching valve 12, the filtration tank 13, the second switching valve 14, and the water tank 15. The second flow path is a flow path that connects, in the water flow direction, the water tank 15, the backwash pump 17, the second switching valve 14, the filtration tank 13, the first switching valve 12, and a drain.

[0032] The control panel 20 is a control device that controls each component of the water treatment device 1. The control panel 20 includes, for example, a communication unit, an input unit, an interface, a display unit, a memory unit 31, and a control unit 32. The communication unit is controlled by the control unit. The communication unit is any communication interface that can communicate with a communication terminal using wireless communication technology such as wired communication technology like USB, short-range wireless communication technology like Bluetooth (registered trademark) (e.g., the BLE standard), Wi-Fi (registered trademark), or NFC, general-purpose wireless communication technology including mobile phone lines like LTE (registered trademark), and long-range wireless communication technology including dedicated wireless communication technology like Sigfox (registered trademark). Here, the communication terminal is an external communication device.

[0033] For example, when the water treatment device 1 is shipped or undergoes maintenance, the communication unit communicates with an inspection communication terminal to receive data such as various parameters of the water treatment device 1, such as functional parameters, internal parameters, and external parameters, various programs for controlling the operation of the pump 11 and backwash pump 17 and managing the lifespan of the filtration tank 13 based on water quality, water flow rate, water flow time, etc., as well as change instructions for changing this data and programs, and transmits them to the memory unit and control unit.

[0034] The input unit is an input interface for receiving user input, and is, for example, an operation panel including buttons.

[0035] The interface is connected to the pump 11, the first switching valve 12, the second switching valve 14, and the backwash pump 17. The interface can also be electrically connected to other devices. That is, the interface is a terminal or circuit to which various devices are electrically connected.

[0036] The display unit includes, for example, a display device such as a segment display, a liquid crystal display, or an organic EL display, or a lighting unit using an LED or the like.

[0037] The storage unit 31 is a storage medium from which data can be read and written. The storage unit 31 includes so-called memory or storage. For example, the storage unit 31 includes non-volatile memory such as EEPROM (registered trademark), ROM, RAM, or NAND flash memory. The storage unit 31 also includes an SSD equipped with flash memory. However, the storage unit 31 is not limited to these, and various storage media can be used.

[0038] The memory unit 31 stores data such as various parameters, such as functional parameters, internal parameters, and external parameters, used by the control unit 32, data on the filter material 23 of the filter tank 13, and various data and programs used for controlling the pump 11, the first switching valve 12, the second switching valve 14, and the backwash pump 17, and for managing the lifespan of the filter tank 13.

[0039] The control unit 32 is a processor. The control unit 32 is, for example, a microcomputer. The control unit 32 is not limited to a microcomputer and may be a CPU, FPGA, DSP, DSC, or other general-purpose or dedicated processor. Furthermore, when a module including a processor is used in the communication unit or the like, the control unit 32 may be the module. The control unit 32 drives and controls the pump 11, the first switching valve 12, the second switching valve 14, and the backwash pump 17 based on various data and programs stored (contained) in the memory unit 31. The control unit 32 controls the rotation speeds of the pump 11 and the backwash pump 17 by varying the output frequency.

[0040] The control unit 32 controls, for example, the pump 11, the first switching valve 12, and the second switching valve 14 to perform a normal process, which is a normal operation in which raw water from the supply source 100 supplied to the pump 11 is filtered, and a backwash process, which is a backwash operation in which treated water is backflowed into the filtration tank 13 using the first switching valve 12, the second switching valve 14, and the backwash pump 17 to clean the filtration tank 13.

[0041] For example, as a normal process, the control unit 32 controls the first selector valve 12 to fluidly connect the pump 11 and the filtration tank 13, and controls the second selector valve 14 to connect the filtration tank 13 and the water storage tank 15. The control unit 32 also controls the drive of the pump 11 to supply raw water to the filtration tank 13, treat the raw water in the filtration tank 13, and store the treated water in the water storage tank 15. The control unit 32 also starts the drive of the pump 11 when it receives a signal output from the water level detector 16 when the water level in the water storage tank 15 is at a level for normal treatment. The control unit 32 also stops the pump 11 when it receives a signal output from the water level detector 16 after the water level in the water storage tank 15 reaches a level for normal treatment, or when the conditions for backwash treatment are met. In this way, as a normal process, the control unit 32 controls the pump 11, the first selector valve 12, and the second selector valve 14 to perform normal operation.

[0042] For example, as a backwash process, the control unit 32 controls the first selector valve 12 to fluidly connect the filtration tank 13 and the drain, and controls the second selector valve 14 to connect the filtration tank 13 and the backwash pump 17. The control unit 32 also stops the pump 11 and drives and controls the backwash pump 17 to supply treated water from the water storage tank 15 to the filtration tank 13 and backflow the treated water within the filtration tank 13, thereby cleaning the filtration tank 13 with the treated water and discharging the treated water that has passed through the filtration tank 13 from the drain. After starting the operation of the backwash pump 17, the control unit 32 stops the backwash pump 17 when the raw water has been backflowed into the filtration tank 13 for a time or amount that is preset and stored in the memory unit 31. As described above, as a backwash process, the control unit 32 controls the first selector valve 12, the second selector valve 14, and the backwash pump 17 to perform a backwash operation.

[0043] The backwashing process performed by the control unit 32 includes a first backwashing process and a second backwashing process which have different start conditions.

[0044] The first backwashing process is a so-called time backwashing process in which the control unit 32 performs a backwashing operation every backwashing time T (hereinafter also referred to as the designated backwashing time) that is preset and stored in the memory unit 31. For example, the designated backwashing time T is the time at which the predetermined backwashing process is performed, or the time from the end of the previous backwashing process to the time at which the next backwashing process is performed. In this way, the control unit 32 performs the backwashing process as the first backwashing process when the preset designated backwashing time T is reached.

[0045] The second backwashing process is a backwashing process performed by the control unit 32, for example, when the water quality detected by the automatic water quality monitoring device 18 is a predetermined water quality that can be determined to indicate a leak of the target components. For example, as the second backwashing process, the control unit 32 compares the water quality detected by the automatic water quality monitoring device 18 with a predetermined threshold value for backwashing, which is stored in the automatic water quality monitoring device 18 or the memory unit 31. The backwashing process is performed when the water quality detected by the automatic water quality monitoring device 18 is equal to or exceeds the threshold value. The water quality and threshold value are, for example, the content of the target components per unit volume of raw water. That is, the second backwashing process is performed when the function of the filter material 23 at the height position H2 where the intermediate water intake 24 is located is impaired and there is a risk of the target components leaking to the secondary side of the filtration tank 13 if normal processing is continued.

[0046] As an example, as the second backwash process, when the control unit 32 determines that the second backwash operation should be performed when the water quality detected by the automatic water quality monitoring device 18 is a predetermined water quality, it performs an "immediate backwash process" in which the backwash operation is performed immediately.

[0047] This immediate backwashing process will be explained using Figures 3 and 4. Figure 3 is an explanatory diagram illustrating the information displayed in Figures 4 to 6 and Figures 8 to 10. Figure 4 is an example of an immediate backwashing process. As shown in Figure 3, the rectangular blocks shown in Figure 4 indicate raw water with different iron concentrations by the color (hatching) within the frame, and the numbers within the blocks indicate an example of the cumulative value of the amount of water treated by the filter material 23 in the filter tank 13 after the backwashing process until the next backwashing process.

[0048] As a specific example, as shown in Figures 3 and 4, three types of rectangular blocks each represent an example of a different iron concentration in raw water. For example, the vertically hatched blocks shown in Figures 3 and 4 represent raw water (1) with an iron concentration at the time of water quality testing of the supply source 100 when the water treatment device 1 was installed (initial selection). Furthermore, the open blocks without hatching shown in Figures 3 and 4 represent raw water (2) with an iron concentration lower than that at the time of initial selection. The diagonally hatched blocks shown in Figures 3 and 4 represent raw water (3) with an iron concentration higher than that at the time of initial selection.

[0049] For convenience of explanation, the volume of one block is 1m 3 The maximum amount of treated water at the intermediate water intake 24 of the filter material 23 of the filter tank 13 is 10 m 3 , 15m in raw water (2) 3 , 5m in raw water (3) 3Here, the maximum treated water volume at the intermediate water inlet 24 is the maximum treated water volume at which, when each raw water (1)-(3) passes through the filter media 23, iron is captured, and the filter media 23's iron capturing function at the height position H2 of the intermediate water inlet 24 decreases, causing leakage of the target components at the intermediate water inlet 24. However, this is the treated water volume at which the iron capturing function of the filter media 23 can be maintained at a position lower than the height position H2 of the intermediate water inlet 24, but for reasons of leakage risk and economy, it is desirable to perform the second backwash process. This is because, since raw water is supplied above the filter media 23 and flows downward, the degradation of the filter media 23's capturing function progresses from above. Also, in each figure, the gap between adjacent blocks indicates that the pump 11 is stopped, and when adjacent blocks are adjacent, it indicates that the pump 11 is operating continuously.

[0050] As shown in FIG. 4, in the immediate backwashing process, first, the previous backwashing process is completed, and normal processing is performed. Raw water (1) is supplied to the filtration tank 13 by the pump 11, and 10 m 3 As the treatment of raw water (1) progresses, the water quality obtained from the automatic water quality monitoring device 18 exceeds a threshold value, causing leakage of the components to be removed at the intermediate water inlet 24. When the control unit 32 determines that leakage of the components to be removed is occurring at the intermediate water inlet 24, it performs a backwashing process. Furthermore, the control unit 32 compares the water quality obtained from the automatic water quality monitoring device 18 with a threshold value to determine leakage of the components to be removed at the intermediate water inlet 24. Therefore, as shown in the raw water (2) block and the raw water (3) block in FIG. 4, even if the iron concentration of the raw water has changed since the initial selection, the control unit 32 can determine leakage of the components to be removed at the intermediate water inlet 24 regardless of changes in the maximum treatment water volume, which varies depending on the concentration of the raw water. Thus, the immediate backwashing process is a backwashing process that the control unit 32 performs as a second backwashing process without waiting for the first backwashing process.

[0051] In addition, the second backwashing process is not limited to an immediate backwashing process, and may be performed selectively with the immediate backwashing process, or alternatively, may be performed instead of the immediate backwashing process, i.e., a specific backwashing process that performs backwashing after a predetermined time has elapsed after determining that a component to be removed has leaked at the intermediate water sampling port 24.

[0052] As another example, the control unit 32 may determine to perform the second backwash operation when the water quality detected by the automatic water quality monitoring device 18 is a predetermined water quality, and then select whether to perform an "immediate backwash operation" or a "specific backwash operation" when a specific condition is met. Here, the "specific backwash operation" refers to a backwash operation that is performed at a predetermined timing different from that of the immediate backwash operation, and information for selecting the specific backwash operation and the timing to perform the backwash operation as the specific backwash operation are set in advance and stored in the memory unit 31.

[0053] The selection judgment made by the control unit 32 is a judgment as to whether or not to perform immediate backwashing processing when taking into consideration leakage from the filtration tank 13, specifically, a judgment as to whether immediate backwashing processing is necessary, or whether a specific backwashing processing can be performed with a start timing later than immediate backwashing processing without the risk of leakage from the filtration tank 13 even if immediate backwashing processing is not performed.

[0054] For example, as a first example of selection and determination, the remaining time t2 until the next first backwashing process is calculated from the specified backwashing time T and the elapsed time t1 since the previous backwashing process, and a determination is made as to whether or not the components to be removed will leak from the filtration tank 13 to the secondary side if the next first backwashing process (specified backwashing time) is waited for based on these times t1 and t2 and a safety factor that determines the risk of leakage from the filtration tank 13. For example, if it is determined that the components to be removed will leak from the filtration tank 13 to the secondary side if the next first backwashing process is waited for, the control unit 32 performs an "immediate backwashing process," and if it is determined that the components to be removed will not leak from the filtration tank 13 to the secondary side if the next first backwashing process is waited for, the control unit 32 performs a "specified backwashing process" as the first backwashing process (i.e., a backwashing process after the next specified backwashing time has been reached) or a backwashing process after a time shorter than the time t2 until the first backwashing process has elapsed.

[0055] A first example of this selection and judgment will be described with reference to Fig. 5. First, after the previous backwashing process is completed, normal processing is performed, and raw water (1) is supplied to the filtration tank 13 by the pump 11. 3 The treatment of raw water (1) progresses, for example, 3 Then, when the raw water concentration increases and changes from raw water (1) to raw water (3), the concentration of the raw water increases by 10m 3 Without waiting for the treatment of the treated water, the water quality acquired from the automatic water quality monitoring device 18 exceeds a threshold, and a leak of the component to be removed occurs at the intermediate water inlet 24. When the control unit 32 determines that a leak of the component to be removed occurs at the intermediate water inlet 24, it makes a selection decision. In the first example shown in FIG. 5 , for example, the control unit 32 calculates the time t2 until the next specified backwash time from the time t1 from the end of the backwash process performed when the previous specified backwash time has arrived to the time when it is determined that a leak of the component to be removed occurs at the intermediate water inlet 24, and the specified backwash time T. Then, the control unit 32 determines whether to perform an immediate backwash process or a specific backwash process based on the times t1 and t2 and the safety factor stored in the memory unit 31.

[0056] Here, the safety factor is calculated, for example, from the stack height H1 of the filter media 23 and the height position H2 of the intermediate water inlet 24 from the bottom surface of the filter media 23. As a specific example, the safety factor Y (%) is calculated from Y = 1 / (1 - H2 / H1) × 100. For example, if the height position H2 of the intermediate water inlet 24 is set to a position 50% of the stack height H1 of the filter media 23, the safety factor is 200%.

[0057] If the control unit 32 determines from the times t1, t2 and the safety factor that performing the next first backwashing process based on the specified backwashing time T will not result in leakage of the components to be removed from the filtration tank 13, then it will, for example, wait for the specified backwashing time before performing the first backwashing process.If the control unit 32 determines from the times t1, t2 and the safety factor that waiting for the next first backwashing process will result in leakage of the components to be removed from the filtration tank 13, then it will perform the backwashing process immediately.

[0058] As a second example of the selection determination, the selection determination may be performed based on the treatment flow rate instead of time. For example, when the control unit 32 determines that a leak of the target component is occurring at the intermediate water inlet 24, as shown in FIG. 6, the control unit 32 calculates an estimated treatment water volume Q2 from the time t2 until the next first backwashing process to the next first backwashing process based on the treatment water volume Q1 from the previous backwashing process, and determines whether this estimated treatment water volume Q2 is equal to or less than the amount of treatment water that can be processed by the filter material 23 below the height position H2. The treatment water volume Q1 may be calculated from the rotation speed of the pump 11, or may be calculated from the actual water volume measured using a flow detector. The estimated treatment water volume Q2 may be calculated from the time t2, the performance of the pump 11, the current or past water level in the water tank 15, the amount of water used at the water supply destination, or may be calculated from the treatment water volume Q1 and a safety factor. For example, if the control unit 32 determines that the estimated treated water volume Q2 will exceed the amount of treated water that can be treated by the filter material 23 below the height position H2 if waiting for the next first backwash process, and that the components to be removed will leak from the filter tank 13 to the secondary side, the control unit 32 performs an immediate backwash process, and if the control unit 32 determines that the estimated treated water volume Q2 is less than the amount of treated water that can be treated by the filter material 23 below the height position H2 until the next first backwash process, and that the components to be removed will not leak from the filter tank 13 to the secondary side, the control unit 32 performs the first backwash process as a ``specific backwash process.''

[0059] The specific backwashing process may be performed, for example, when the water level in the water tank 15 reaches a predetermined level. As a specific example, when the control unit 32 determines that a leak of the target component is occurring at the intermediate water inlet 24 during the second backwashing process, it performs a selection decision similar to the first and second examples described above. Then, when the control unit 32 determines that the specific backwashing process is to be performed, it determines whether the water level in the water tank 15 detected by the water level detector 16 is at a predetermined level. If it determines that the water level is equal to or greater than the predetermined level, it performs the backwashing process as a "specific backwashing process." If it determines that the water level is below the predetermined level, it continues normal processing. Then, when the water level reaches the predetermined level or reaches the specified backwashing time T, it stops the pump 11 and performs the backwashing process. Here, the predetermined water level may be the stopping water level of the pump 11. Alternatively, the predetermined water level may be an intermediate water level between the driving water level and the stopping water level of the pump 11. In this case, the water level detector 16 may be a sensor capable of detecting the intermediate water level.

[0060] Next, an example of a processing method for the second backwashing process by the control unit 32 configured as above will be described using the flowchart in Fig. 7. In this description, an example will be described in which the control unit 32 selects and determines whether to perform the immediate backwashing process or the specific backwashing process as the second backwashing process.

[0061] First, when the water level detected by the water level detector 16 is the driving water level of the pump 11, the control unit 32 drives the pump 11 (step ST1). As a result, the raw water is treated in the filtration tank 13, and the treated water is stored in the water storage tank 15.

[0062] The control unit 32 monitors the quality of the water sampled through the intermediate water sample inlet 24 (step ST2). Specifically, the control unit 32 receives a signal corresponding to the water quality output from the automatic water quality monitoring device 18 continuously or at predetermined time intervals. The control unit 32 compares the water quality obtained from the automatic water quality monitoring device 18 with a threshold value and determines whether the obtained water quality is equal to or higher than the threshold value, i.e., whether the components to be removed are leaking from the intermediate water sample inlet 24 in an amount exceeding the allowable amount (step ST3). In this embodiment, the control unit 32 determines whether the filtering material 23's ability to remove the components to be removed has decreased, from the treated water sampled through the intermediate water sample inlet 24, which is located at a height position H2 lower than the stack height H1 of the filtering material 23.

[0063] If the water quality obtained from the automatic water quality monitoring device 18 is below the threshold value, i.e., if it does not exceed the allowable amount of components to be removed at the intermediate water inlet 24 and the components to be removed are not leaking at the intermediate water inlet 24 (NO in step ST3), the control unit 32 continues to monitor the water quality at the intermediate water inlet 24 in step ST3.

[0064] If the water quality obtained from the automatic water quality monitoring device 18 is above the threshold value, i.e., if the amount of components to be removed at the intermediate water inlet 24 exceeds the allowable amount (YES in step ST3), the control unit 32 determines that a leak of the components to be removed is occurring at the intermediate water inlet 24, and performs a backwashing process selection determination to determine whether or not to perform immediate backwashing (step ST4).

[0065] When it is determined that immediate backwashing processing should be performed (YES in step ST4), the control unit 32 stops the pump 11 and switches the first switching valve 12 and the second switching valve 14 to drive the backwash pump 17, causing the treated water from the water storage tank 15 to flow back through the filtration tank 13 for a predetermined period of time to perform backwashing (step ST5).

[0066] If it is determined that immediate backwash processing will not be performed (YES in step ST4), the control unit 32 will stop the pump 11, switch the first switching valve 12 and the second switching valve 14, drive the backwash pump 17, and perform backwash processing for a predetermined period of time, for example, when a specific condition is reached.

[0067] Then, after the backwashing process has been performed for a predetermined time in steps STS5 and ST6, the control unit 32, for example, stops the backwashing pump 17 to terminate the backwashing process, controls the first switching valve 12 and the second switching valve 14 to fluidly connect the pump 11, the filtration tank 13, and the water storage tank 15, and performs normal processing to drive the pump 11.

[0068] In the water treatment device 1 configured as described above, the filtration tank 13 is provided with an intermediate water inlet 24 that can be used to sample water at a height H2 lower than the stack height H1 of the filtration media 23. The quality of the treated water sampled through the intermediate water inlet 24 is monitored by the automatic water quality monitoring device 18 and the control unit 32. This configuration allows a first backwashing process to be performed every preset backwashing time T. Furthermore, when the water quality monitored by the automatic water quality monitoring device 18 is determined to be a predetermined water quality (i.e., when a component leaks from the intermediate water inlet 24), a second backwashing process can be performed without waiting for the first backwashing process. Therefore, depending on the degree of deterioration of the filtration media 23, the filtration tank 13 can be backwashed before leakage of the target component from the filtration tank 13 to the secondary side occurs. Furthermore, when a backwashing process is performed before the first backwashing process, it can be performed based on the water quality actually measured at the intermediate water inlet 24. This prevents unnecessary backwashing, thereby reducing the risk of leakage and unnecessary backwashing of the filtration media.

[0069] Specifically, for example, in Comparative Example 1, in an example of a conventional backwashing process, as shown in FIG. 8, a backwashing process (time backwashing) was performed at each designated backwashing time. That is, only the first backwashing process of this embodiment was performed. For example, as in the example on the left side of FIG. 8, when a backwashing process was performed at each backwashing time, the maximum amount of treated water from the filter material 23 of the filter tank 13 was 10 m 3 When the amount of treated water treated by the filter 23 during the backwashing process is 10 m3 However, as shown in the example in the center of Figure 8, the amount of treated water processed by the filter material 23 during backwashing is 10 m 3 Less than 6m, for example 3 On the other hand, as shown in the example on the right side of Figure 8, if the amount of treated water treated by the filter material 23 during backwashing is 10 m 3 Beyond, for example, 11m 3 If the amount of treated water is less than this, backwashing will be insufficient, the performance of the filter material 23 will be reduced, and there is a risk that the components to be removed will leak to the secondary side of the filter tank 13.

[0070] In addition, when backwashing is performed for a certain period, as shown in FIG. 9, as Comparative Example 2, when the raw water concentration changes from the raw water (1) at the time of initial selection and the concentration of the components to be removed in the raw water decreases, the amount of treated water between backwashing treatments is 10 m 3 Even if the raw water (2) is treated with the filter material 23, the maximum amount of treated water is 15 m 3 In addition, as in raw water (3), if the raw water concentration changes from the initially selected raw water (1) and the concentration of the components to be removed in the raw water increases, the amount of treated water between backwash treatments will be 10 m 3 Less than, for example, 8m 3 Even if the raw water (3) can be treated with the filter material 23, the maximum treatment volume is 5 m 3 This will result in insufficient cleaning.

[0071] Also, for example, in Comparative Example 3, in an example of a conventional backwashing treatment, backwashing treatment (treatment amount backwashing) was performed for each predetermined amount of treated water, as shown in FIG. 10. For example, the predetermined amount of treated water for performing backwashing treatment is determined based on the component concentrations of raw water at the time of initial selection. Therefore, as shown on the left side of FIG. 10, if the raw water (1) at the time of initial selection is used, the amount of treated water is 10 m 3 However, if the concentration of the target components in the raw water (2) has decreased since the initial selection, the amount of treated water will be 10 m 3 Even so, the maximum amount of water that can be treated with the filter material 23 is 15 m 3In addition, as in raw water (3), if the raw water concentration changes from the initially selected raw water (1) and the concentration of the components to be removed increases, the amount of treated water between backwash treatments will be 10 m 3 Even if the raw water (3) can be treated with the filter material 23, the maximum treatment volume is 5 m 3 This will result in insufficient cleaning.

[0072] In contrast, the water treatment device 1 of this embodiment monitors for leakage of target components at the intermediate water inlet 24 and performs backwashing when leakage occurs. This allows for timed backwashing while preventing insufficient backwashing even when the raw water concentration changes or the treatment flow rate increases. Furthermore, because the system monitors leakage at the intermediate water inlet 24 based on the measured water quality, leakage of target components from the filtration tank 13 can be prevented even when the raw water quality fluctuates, and the safety margin required for the specified backwashing time can be minimized. Therefore, the water treatment device 1 can reduce the risk of leakage and prevent unnecessary backwashing (excessive backwashing). Furthermore, the water treatment device 1 can perform backwashing without leaking even when the amount of treated water increases, and does not perform excessive backwashing even when the amount of treated water decreases. Furthermore, the water treatment device 1 maintains a safety margin, ensuring constant leak prevention even when the filter media 23 deteriorates and the amount of target components removed by the filter media 23 fluctuates. Furthermore, since the water treatment device 1 is not configured to monitor the treated water on the secondary side of the filtration tank 13, the treated water is monitored on the secondary side of the filtration tank 13, and there is no need to install an additional removal device in case a leak occurs, which prevents an increase in manufacturing costs.

[0073] Furthermore, in water treatment device 1, height position H2 of intermediate water inlet 24, through which treated water monitored by automatic water quality monitoring device 18 is sampled, satisfies the relationship H1 / 4≦H2≦H1 / 2, where H1 is the stack height of filter media 23. This is because if height position H2 of intermediate water inlet 24 is located at a position higher than H1 / 2, the timing of backwashing would be too early and uneconomical, and if it is located at a position lower than H1 / 4, there is an increased risk of leakage of the components to be removed from filtration tank 13. Therefore, by setting intermediate water inlet 24 as the water sampling position, backwashing can be performed at an economical timing and the risk of leakage can be reduced.

[0074] In the above example, the water treatment device 1 has been described as performing a first backwash process that is performed at every specified backwash time T and a second backwash process that is performed when a leak of the component to be removed occurs at the intermediate water intake port 24, but this is not limited to this.For example, the water treatment device 1 may be configured to perform only the second backwash process, or may be configured to perform a backwash process other than the first backwash process and the second backwash process.

[0075] As described above, the water treatment device 1 may be configured without the water storage tank 15. In this case, the drive and stop of the pump 11 may be controlled by the pressure and / or flow rate on the secondary side of the filtration tank 13. In such a water treatment device 1, a water outage can be prevented by performing a specific backwashing process when performing the second backwashing process.

[0076] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention. [Explanation of symbols]

[0077] 1...water treatment device, 11...pump, 12...first switching valve, 13...filtration tank, 14...second switching valve, 15...water storage tank, 15m...maximum treated water volume, 16...water level detector, 17...backwash pump, 18...automatic water quality monitoring device, 19...piping, 19a...first pipe, 19b...second pipe, 19c...third pipe, 19d...fourth pipe, 19e...fifth pipe, 19f...sixth pipe, 19g...seventh pipe, 19h...eighth pipe, 20...control panel (control device), 21...tank body, 21a...legs, 21b...bottom, 21c...body, 21d...ceiling, 22...filter, 23...filtering material, 24...intermediate water sampling port, 31...memory unit, 32...control unit, 100...supply source.

Claims

1. A filtration tank having a filter medium for removing target components from raw water and an intermediate water intake port for extracting treated water treated with the filter medium at the center of the stack height of the filter medium; a backwash pump that causes the treated water to flow back through the filter material to clean it; an automatic water quality monitoring device connected to the intermediate water intake port and monitoring the water quality of the treated water taken from the intermediate water intake port; a control device that controls the backwash pump to perform backwashing of the filter material when the water quality of the treated water monitored by the automatic water quality monitoring device is a predetermined water quality that is determined to be a leak of the component to be removed; A water treatment device comprising:

2. The water treatment device according to claim 1, wherein the control device selectively performs an immediate backwashing process in which the backwashing process is performed immediately when the water quality of the treated water monitored by the automatic water quality monitoring device is the predetermined water quality, and / or a specific backwashing process in which the backwashing process is performed at a timing different from the immediate backwashing process when the automatic water quality monitoring device detects that the water quality of the treated water is the predetermined water quality.

3. The water treatment device described in claim 2, wherein the control device selects the immediate backwashing process and the specific backwashing process based on the time or amount of treated water from the previous backwashing process to the detection of the specified water quality, the time or amount of water from the detection of the specified water quality to the performance of the specific backwashing process, and a safety factor.

4. a pump for supplying the raw water to the filtration tank; a water storage tank for storing the water treated in the filtration tank; a water level detector for detecting the water level of the water tank; The water treatment device described in claim 2 or claim 3, wherein when the specific backwash process is selected, if the water level in the water tank is lower than a predetermined water level, the control device continues to drive the pump, and if the water level in the water tank is higher than the predetermined water level, the control device stops the pump and drives the backwash pump.

5. 2. The water treatment device according to claim 1, wherein a height H2 at which the intermediate water intake port is provided satisfies H1 / 4≦H2≦H1 / 2, where H1 is the stack height of the filter media.

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