JP2022130840A - water treatment system - Google Patents

Abstract

To provide a water treatment device that decreases pressure therein when being stopped, so as to perform stable supply of medical agents.SOLUTION: A water treatment system comprises: a water treatment device 1 which has a medical agent supply part 3 that adds medical agents in a passage of raw water inflow piping 10 and a clean water ejection piping 20 through which filtered treated water is ejected from a filtering part 2; connection piping 80 connected to the raw water inflow piping 10; and an electric pump 4 that supplies water to the connection piping 80, where the medical agent supply part 3 is arranged upper than the raw water inflow piping 10 and the clean water ejection piping 20 and the connection piping 80 is arranged in a vertical direction so that a downstream side thereof is upper. The electric pump 4 that can reflux water when being stopped and the connection piping 80 having a larger diameter enable pressure acting on the water treatment device 1 during operation to escape through the raw water inflow piping 10 toward a front stage side of the electric pump 4 and enable pressure in the water treatment device 1 to decrease during stoppage, so that water level in the medical agent supply part 3 lowers, which can prevent water from contacting medical agents while stopping the water treatment device 1, so that the stable concentration of the medical agents can be obtained.SELECTED DRAWING: Figure 1

Description

The present invention relates to a water treatment device that purifies water by filtration and chemical addition.

Conventionally, a chemical supply device that brings a solid oxidant into contact with water has been used to supply an oxidant in a water treatment apparatus. For example, when purifying well water, it is possible to oxidize raw water to be purified by using a chemical feeder that gradually dissolves solid calcium hypochlorite.

In a system that injects drugs with a metering pump, or a drug supply device that elutes a constant amount of drug regardless of the flow rate, it is necessary to change the flow rate of the metering pump according to the flow rate of the injection pipe, which is very expensive. be.

As shown in FIG. 6 , in the solid medicine supply device 101 , raw water is introduced from the water intake 102 to bring the raw water into contact with the water-soluble solid medicine 103 . When water flows into the drug contact phase 104, the amount of the water-soluble solid drug 103 in contact with the raw water increases as the flow rate increases within a certain flow rate range. With this mechanism, the drug is eluted when the flow rate is increased, and the elution of the drug can be suppressed when the flow rate is stopped (see, for example, Patent Document 1).

Japanese Utility Model Publication No. 58-49836

In such a water treatment apparatus, since the water and the chemical are in contact even when the apparatus is stopped, the chemical continues to elute, making it difficult to supply a chemical solution with a stable concentration. That is, since the chemical is eluted into the raw water that remains when the water treatment apparatus is stopped, the concentration of the chemical becomes high when the water treatment apparatus is restarted, and the chemical is unnecessarily eluted, increasing the consumption of the chemical.

Therefore, the present invention is intended to solve the above-mentioned conventional problems, by reducing the internal pressure inside the water treatment apparatus when it is stopped, suppressing the contact between the water and the chemical, and obtaining a chemical solution with a desired concentration. It is an object of the present invention to provide a water treatment device capable of

And, in order to achieve this object, the water treatment system according to the present invention
a filtration unit containing a filter medium;
A raw water inflow pipe that allows raw water to flow into the filtration unit;
a chemical supply unit that adds a chemical within the route of the raw water inflow pipe;
a water treatment apparatus having a purified water discharge pipe for extracting treated water after filtration from the filtering unit;
a connecting pipe connected to the raw water inflow pipe;
Having an electric pump that sends water to the connection pipe,
The chemical supply unit is arranged above the raw water inflow pipe and the purified water discharge pipe,
The connecting pipe achieves the intended purpose by arranging it vertically so that the downstream side faces upward.

According to the present invention, in the water treatment apparatus, the pressure inside the water treatment apparatus is released from the raw water inflow pipe side to the outside when the water treatment apparatus is stopped, thereby suppressing the increase in the water level in the chemical supply unit and preventing the water from flowing out during the stop of the water treatment apparatus. There is an effect that it is possible to prevent the chemical from coming into contact with the liquid and to supply the chemical with the desired concentration.

Schematic diagram of the overall configuration of a water treatment apparatus according to Embodiment 1 of the present invention Schematic diagram showing the flow of water during backwashing of the same water treatment equipment Schematic diagram showing the flow of water during rinsing of the same water treatment equipment Cross-sectional view of the filtration part and switching valve of the same water treatment equipment Cross-sectional view of the chemical supply part of the same water treatment device Schematic diagram showing the configuration of a conventional water treatment device

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
The water treatment apparatus 1 according to the present embodiment uses well water or water stored in a water tank as raw water, and a filtration process for removing metal ions and turbidity components contained in this raw water, and a filtration process to remove accumulated in the system. Backwashing is performed to discharge metal ion aggregates and turbidity components out of the system.

FIG. 1 is a schematic diagram showing the overall configuration of a water treatment apparatus 1 of the present embodiment and showing the flow of water during filtration.

As shown in FIG. 1, the water treatment apparatus 1 has a filtration unit 2 containing a filter medium and a chemical supply unit 3 for adding chemicals to raw water. It is configured by connecting with piping. The filtration unit 2 removes metal ions and turbidity components from the raw water to purify the raw water. Contaminants collected in the filtering part 2 are discharged out of the device after being subjected to backwashing and rinsing treatments, so that the filtering part 2 can be kept clean and can be used repeatedly. The backwashing process is a process in which the raw water flows in the reverse direction in the filtration unit 2 to discharge dirt. In the rinsing process, after the backwashing process, the raw water is passed through the filtration unit 2 in the filtration direction to discharge the separated contaminants out of the apparatus. A raw water inflow pipe 10 is used as a pipe for sending raw water to the filtration unit 2, and a purified water discharge pipe 20 is used as a pipe for sending out the water purified in the filtration unit 2 from the filtration unit 2. Backwashing and rinsing operations A backwash drain pipe 40 is used as a pipe for discharging dirt. The purified water is stored in a purified water tank 6 or the like provided outside the water treatment apparatus 1, and is used as domestic water when necessary.

Raw water is sent to the water treatment apparatus 1 by an electric pump 4 connected to the inlet side of the raw water inflow pipe 10 (opposite side of the filtration unit 2). Alternatively, instead of using the electric pump 4, a water tank storing raw water may be provided at a high place, and the raw water may be sent to the water treatment apparatus 1 according to the height difference between the water tank and the water treatment apparatus 1. Alternatively, tap water jointly operated in the area may be directly connected. In this embodiment, in addition to wells, water tanks, taps, etc., water sources include equipment for sending out raw water.

The electric pump 4 is a pump driven by an electric motor that sucks up and discharges well water or water stored in a water tank. An axial flow pump, a mixed flow pump, or the like is used. If the well water level is low, a submersible pump or other submersible pump should be used instead of a suction pump. When used in general households, the depth of the well must be about 1 to 10 meters for shallow wells, and 10 to 30 meters or more for deep wells. Considering the head loss of the downstream piping and water treatment equipment, a pump with a head of 20 meters or more is preferable, and a vortex pump or a jet pump is more preferable. The flow rate discharged by the electric pump is, for example, about 5 liters to 100 liters per minute, and for general household use, a flow rate characteristic of about 5 liters to 50 liters per minute is more preferable.

The raw water inflow pipe 10 and the purified water discharge pipe 20 may be made of materials and structures that can withstand the water pressure of the electric pump 4 . Specifically, for example, vinyl chloride resin, steel pipes, or straight pipes and pipe joints using composite materials thereof can be used because of their durability and ease of processing. It should be noted that the larger the nominal diameter, the lower the water head loss, and for example, the nominal diameter of 13 to 50 mm and the thickness of 1 to 5 mm are preferred. If it is difficult to select a member that can withstand the maximum pressure of the electric pump 4 , it is recommended to install a pressure reducing valve, a pressure regulating valve, and a relief valve between the electric pump 4 and the water treatment device 1 .

The chemical supply unit 3 is provided in the path of the raw water inflow pipe 10 . Although details will be described later, the chemical supply unit 3 adds an oxidizing agent to the raw water, aggregates the metal ions contained in the raw water as substances that are poorly soluble in water, and makes them easier to collect in the filtration unit 2. do.

(Filtration part related)
Next, the filter part 2 and the switching valve 5, which are parts related to the filter part, will be described with reference to FIG.

The filtration unit 2 has a filter medium and a water collecting pipe 70 inside, and purifies the raw water by passing it through. The filtering material inside the filtering part 2 is mainly composed of an upper layer 71 for filtering dirt and a lower layer 72 having a rectifying action. The filter media used for the upper layer 71 are activated carbon, manganese sand, anthracite, etc., and are used in layers of about 1 to 4 types depending on the quality of the raw water. In the filtering section 2 of the present embodiment, the filtering action works centering on the upper layer 71 . The filter material used for the lower layer 72 is composed of gravel or resin with coarse holes for dispersing water flowing in and out of the water collecting pipe. In the lower layer 72 , a gravel layer having a relatively large grain size is provided at the lowest layer to improve the flow of water and prevent the filtering material from flowing out from the bottom of the water collecting pipe 70 . The amount of filtering material in the lower layer 72 is preferably about 1/2 to 1 times the diameter of the filtering section 2. FIG. In addition, it is preferable that the filling amount of the filtering material including the upper layer 71 and the lower layer 72 is about 1/4 to 4/5 times the internal volume of the filtering section 2 .

Filtration unit 2 is connected to external pipes (raw water inflow pipe 10, purified water discharge pipe 20, backwash drain pipe 40) at the top. An inflow port 73 and an outflow port 74 serving as openings are provided inside the filtration unit 2 , and the outflow port 74 is connected to the water collecting pipe 70 .

A switching valve 5 is attached to the upper part of the filtration unit 2, and an external pipe (raw water inflow pipe 10, purified water discharge pipe 20, backwash drain pipe 40) and an inflow port 73 and an outflow port 74 in the filtration unit 2 are connected. are connected, and the communication between the external pipe and the inflow port 73 and the outflow port 74 is switched by the operation. A channel switching piece 75 for switching the channel is provided in the switching valve 5, and by rotating the channel switching piece 75, the direction of communication with the connected piping and the opening is changed. The channel switching piece 75 can be rotated by an external handle or moved by an external motor.

At the time of filtration, the raw water inflow pipe 10 and the inflow port 73 and the outflow port 74 and the purified water discharge pipe 20 are brought into communication by operating the channel switching piece 75 . On the other hand, during the backwashing process, by operating the channel switching piece 75, the raw water inflow pipe 10 and the outflow port 74 are communicated, and the inflow port 73 and the backwash drain pipe 40 are communicated with each other. Further, during the rinsing process, the flow path switching piece 75 is operated to allow the raw water inflow pipe 10 and the inflow port 73 to communicate with each other, and the outflow port 74 and the backwash drain pipe 40 to communicate with each other.

Various operations are possible depending on the type of piping connected to the switching valve 5 . For example, raw water can be sent directly to the purified water tank 6 by connecting the raw water inflow pipe 10 and the purified water discharge pipe 20 .

Although the switching valve 5 is used in this embodiment, the flow paths can be switched by using a plurality of valves instead of using the switching valve 5 .

In such a configuration, the flow of water during filtration and backwashing will be described. During the filtration process, water flows in the filtration section 2 as follows, and purified water is obtained from the outlet 74 .

[Flow path in filtration unit 2 during filtration]
Inflow port 73→upper layer 71→lower layer 72→collection pipe 70→outflow port 74.

During the rinsing process, water flows in the filtering section 2 in the same manner as during the filtering process, but the water containing dirt after the backwashing process described later flows out from the outlet port 74 . Therefore, the outflow port 74 is communicated with the backwash drain pipe 40 and discharged to the outside.

In addition, dirt collected in the filtering section 2 by the filtering process can be discharged by backwashing process. During the backwashing process, water flows as follows and dirt is discharged from the inlet 73 .

[Flow path in filtration unit 2 during backwashing]
Outlet 74→water collection pipe 70→lower layer 72→upper layer 71→inlet 73
(Drug supply unit)
Next, the drug supply unit 3 will be described with reference to FIGS. 1 and 5. FIG.

The chemical supply unit 3 is provided to promote aggregation of metal ions contained in the raw water by the chemical put therein and facilitate the supplementation by the filtration unit 2 . The chemical supply unit 3 is provided on the upper part of the pipe that rises upward from the raw water inlet 11, is arranged at the top of the water treatment device 1, and includes an inflow channel 31, a chemical channel 32, a bypass channel 33, and an outflow channel. 34. The inflow path 31 is connected to the raw water inflow pipe 10 and allows the raw water to flow into the drug supply section 3 . The drug channel 32 branches off from the inflow channel 31 and dissolves the drug. The bypass passage 33 is provided with a throttle portion 33a, which is also branched from the inflow passage 31, to adjust the concentration of the chemical solution to a required level. After branching from the inflow path 31 , the bypass path 33 is connected to the outlet side of the outflow path 34 . The outflow channel 34 merges with the drug channel 32 and the bypass channel 33 and is again connected to the raw water inflow pipe 10 to send out raw water containing the drug to the raw water inflow pipe 10 . As shown in FIG. 5, the drug path 32 includes an ejection tube 52 that rises vertically after being branched, a drug placement portion 53 that contacts the drug at the upper portion of the ejection tube 52 and elutes the drug, and an ejection tube 52. It is composed of a recovery part 54 which is an outer periphery and inside the housing 51 .

The medicine supply part 3 is a substantially closed space except for the openings of the inflow path 31 and the outflow path 34 . The medicine is put in through an inlet (not shown) at the top of the housing 51, which is closed during operation of the device. exists.

The ejection tube 52 is a small-diameter conduit, and is erected with a drug-mounting portion 53 on the upper portion thereof. By reducing the diameter of the lower portion of the ejection pipe 52 and providing the drug placement portion 53 in the upper portion of the ejection pipe 52, the raw water can be brought into contact with the drug at a desired flow rate. The medicine placement part 53 has a size for securing the amount (number) of the medicine to be placed so as to obtain the desired concentration of the medicine with respect to the flow rate of the raw water.

The liquid medicine in which the medicine is dissolved flows out to the collecting part 54 . In the collecting portion 54 , the liquid medicine in which the medicine is dissolved accumulates in the lower portion of the housing 51 and then flows out from the collecting opening 55 to the outflow path 34 . Since the diameter of the ejection pipe 52 is made small and the distance from the inner wall surface of the housing 51 is secured, the liquid level of the raw water in which the drug is dissolved that flows down into the housing 51 is raised to the height of the housing 51. , can be reduced to about 1/2 or less. By accumulating the chemical liquid in the housing 51 at a desired depth, the mixing ratio of the chemical liquid with the raw water in the outflow passage 34 is adjusted.

Also, the flow rate of the raw water flowing through the inflow channel 31 can be adjusted by the flow rate of the raw water flowing through the bypass channel 33 . That is, by adjusting the diameter of the narrowed portion 33a of the bypass 33, the ratio of the flow rates of the raw water flowing through the inflow channel 31 and the bypass 33 is adjusted. In this manner, the drug concentration in the outflow path 34 after confluence can be adjusted to a desired concentration. The flow rate of the raw water flowing through the bypass 33 may be adjusted using a flow rate adjustment valve instead of the throttle portion 33a.

By setting the amount of raw water flowing into the chemical supply unit 3 within a predetermined range and by setting the liquid level in the chemical supply unit 3 to a desired height, the chemical concentration of the raw water flowing out of the chemical supply unit 3 can be adjusted to a desired level. It can be adjusted within the range.

In addition, it is preferable that an air layer always exists in the housing 51 of the drug supply unit 3 . Since the housing 51 is a closed space except for the connecting portion with the raw water inflow pipe 10, once the air disappears and the inside of the housing 51 is filled with water, the water-soluble solid medicine 60 always comes into contact with water and continues to be eluted. It will be. Therefore, in order to send air to the medicine supply unit 3, it is preferable to attach a pipe for supplying air to the raw water inflow pipe 10 or the like.

The medicine loading section 53 is provided with a solid medicine, namely a water-soluble solid medicine 60 . As the water-soluble solid medicine 60, tablets and granules are preferably used. This is because the surface area of the water-soluble solid drug 60 can be increased and a stable solvent concentration can be maintained. Tablets with a diameter of 30 mm and a height of 10 to 20 mm may be used, and granules with a diameter of 5 mm to 15 mm may be used. If the size of the water-soluble solid medicine 60 is small, adjacent medicines will come into contact with water at the same time and stick to each other. If it sticks, only the lower portion of the chemical will come into contact with the water, making it impossible to obtain the desired concentration of chemical. Alternatively, if the size of the water-soluble solid medicine 60 is small, the contact area with the water supplied from the ejection pipe 52 becomes large, making it impossible to obtain the desired concentration of the medicine. Therefore, the water-soluble solid drug 60 having the size described above is used to supply the drug solution with the desired concentration.

Further, the water-soluble solid drug 60 functions to oxidize metal ions contained in the raw water to form aggregates that are sparingly soluble in water, as described above. Various oxidizing agents can be used as the water-soluble solid agent 60, but depending on the required water purification performance, a polymer flocculating agent such as PAC (polyaluminum chloride) or chitosan may be used. When the chemical is added to the raw water, the water-soluble solid chemical 60 should be easily soluble in water. , and does not flow out from the drug placement portion 53. As shown in FIG. In this embodiment, trichloroisocyanuric acid is used.

Since each member of the drug supply unit 3 may be in contact with the drug for a long time, it is better to select a material with low reactivity to the drug, such as PVC (polyvinyl chloride), PMMA (polymethyl methacrylate), or PP (polypropylene). . On the other hand, since the ejection tube 52 requires strength to support the drug mounting portion 53, the material of the ejection tube 52 is vinyl chloride or ABS (acrylonitrile-butadiene-styrene), which is stronger than PP, considering compatibility with the drug. etc. is preferably selected. The outer diameter of the ejection pipe 52 is preferably suppressed to 1/4 or less of the inner diameter of the base 51a or the upper cover 51b. As described above, a space (recovery section 54) for temporarily storing the solution discharged from the placement section outlet 58 after drug supply can be provided outside the ejection tube 52. This is because it is possible to prevent the drug from rising and reaching the drug placement section 53 . For example, when the inner diameter of the base 51a is 130 mm, it is preferable to use a PVC pipe having an outer diameter of about 25 to 40 mm.

(Piping configuration)
As described above, the water treatment apparatus 1 of the present embodiment includes the filtration unit 2, the raw water inflow pipe 10, the purified water discharge pipe 20, and the backwash drain pipe 40 (Fig. 1). The inlet side of the raw water inflow pipe 10 is connected to the discharge port of the electric pump 4 serving as the water source, and the outlet side is connected to the switching valve 5 of the filtering section 2 . A drug supply unit 3 is provided in the path of the raw water inflow pipe 10 , and a bypass pipe 14 bypassing the drug supply unit 3 is provided. This bypass pipe 14 branches at the raw water inflow pipe 10 on the upstream side of the chemical supply unit 3 (branching portion 12), bypasses the chemical supply unit 3, and merges with the raw water inflow pipe 10 on the downstream side of the chemical supply unit 3. (Branch unit 13). A bypass valve 15 is provided in the path of the bypass pipe 14 to open/close the path of the bypass pipe 14 or adjust the flow rate of the bypass pipe 14 .

The filtration unit 2 has two outlets, and one of the outlets is connected to a purified water discharge pipe 20 for extracting water purified inside. The other outlet is connected to a backwash drain pipe 40 for discharging particulate matter (dirt, turbidity components, metal aggregates, etc.) collected by the filtration unit 2 during backwashing and rinsing to the outside of the system. It is

Next, the piping structure in the water treatment apparatus 1 and the flow of water in the filtration process and the backwash process will be described.

During the filtration process, as shown in FIGS. 1 and 4A, the raw water inflow pipe 10 is connected from the raw water inlet 11 on the water source side to the filtration unit 2 via the chemical supply unit 3 . In the filtering unit 2, the connection is switched by operating the switching valve 5 so that the raw water inflow pipe 10 and the inflow port 73 are in communication and the outflow port 74 and the purified water discharge pipe 20 are in communication.

In such a piping configuration, water flows as follows during the filtration process.

[Flow path during filtration]
Raw water inlet 11 → (raw water inflow pipe 10 ) → branch 12 → chemical supply unit 3 → branch 13 → switching valve 5 → filtering unit 2 → switching valve 5 → (purified water discharge pipe 20 ) → purified water outlet 21
A check valve 62 is provided in the route of the purified water discharge pipe 20 . Purified water taken out from the purified water outlet 21 is often piped to a purified water tank 6 provided at a high place. The check valve 62 prevents reverse flow of purified water from the purified water tank 6 provided at a high place and prevents reverse flow of water into the filtering section 2 .

Next, the flow of water during backwashing will be described with reference to FIGS. 2 and 4(b). During backwashing, the bypass valve 15 is opened, and the raw water inflow pipe 10 bypasses the chemical supply unit 3 from the raw water inlet 11 on the water source side and connects to the filtration unit 2 via the bypass pipe 14 . In the filtration unit 2, the switching valve 5 is operated to switch the connection so that the raw water inflow pipe 10 and the outflow port 74 are in communication and the inflow port 73 and the backwash drain pipe 40 are in communication. At this time, the flow of water in the filtering section 2 is reversed from that during the filtering process. In the water treatment apparatus 1 according to the present embodiment, by switching the switching valve 5 and the bypass valve 15, the water source (the electric pump 4) can be used as one, and filtration and backwashing can be performed.

During backwashing, water flows as follows.

[Flow path during backwashing]
Raw water inlet 11 → (raw water inflow pipe 10) → branch 12 → (bypass pipe 14) → bypass valve 15 → (bypass pipe 14) → branch 13 → switching valve 5 → filtering unit 2 → switching valve 5 → backwash drain tube 40
In this way, during the backwashing process, after passing through the filtration unit 2, the material is discharged out of the apparatus, so there is no need to add chemicals to agglomerate metal ions and the like. Therefore, during the backwashing process, the raw water is sent to the filtration unit 2 via the bypass pipe 14 bypassing the chemical supply unit 3 . During the backwashing process, the elution of chemicals is suppressed, and the water is supplied to the filtering section 2 in a state close to raw water, and the inside of the filtering section 2 is washed.

In addition, a large flow rate is required for backwashing. Therefore, by increasing the diameter of the bypass pipe 14, a large flow rate of the raw water can be ensured during the backwashing process. On the other hand, during the filtering process, the flow rate is set according to the performance of the filtering section 2 . Therefore, a throttle portion 24 is provided in a portion of the pipe that passes during the filtration process, that is, in the route of the purified water discharge pipe 20 to suppress the flow rate during the filtration process. The combination of the throttle portion 24 and the electric pump 4 allows the flow rate during the filtration process to be a desired design value. The diameter of the bypass pipe 14 is made larger than that of the constricted portion 24 to ensure the flow rate of water passing through the bypass pipe 14 during the backwashing process.

In addition, the diameter of the backwash drain pipe 40 is made larger than that of the throttle portion 24 in order to discharge the large flow rate during the backwash process as it is.

Also, the bypass valve 15 may be opened and closed by detecting the pressure or flow rate in the raw water inflow pipe 10 and the purified water discharge pipe 20 . Since the backwashing process and the filtration process have different routes, a difference in pressure is also generated in the raw water inflow pipe 10 . By this pressure difference, the bypass valve 15 can be opened and closed. That is, as the bypass valve 15, a pressure switch provided in the raw water inflow pipe 10 or the purified water discharge pipe 20, or a solenoid valve or an electric valve that opens and closes in response to a signal from a flow meter provided in the pipe in the water treatment apparatus 1 is used. can be

Further, when the switching valve 5 and the electric pump 4 are collectively controlled, the bypass valve 15 and the switching valve 5 can be interlocked to change the flow path. Alternatively, the bypass valve 15 may be opened and closed in conjunction with the operation of the switching valve 5 .

In addition, the water treatment apparatus 1 of the present embodiment can perform a "rinse process" for discharging foreign substances remaining in the pipes during the backwash process. This rinsing process will be described with reference to FIGS. 3 and 4(c). The rinsing process can be performed by changing the flow path of the switching valve 5 . Specifically, the bypass valve 15 is opened. The switching valve 5 switches so that the raw water inflow pipe 10 and the inflow port 73 are communicated, and the outflow port 74 and the backwash drain pipe 40 are communicated. In such a state, the water flows in the filtering section 2 in the same direction as the filtering process, and the water that has passed through the filtering section 2 is discharged through the backwash drain pipe 40 .

By operating the valve in this manner, water flows as follows during the rinsing process.

[Flow path during rinsing]
Raw water inlet 11→(Raw water inflow pipe 10)→Branch portion 12→(Bypass pipe 14)→Branch portion 13→Switching valve 5→Filtration unit 2→Switching valve 5→Backwash drain pipe 40
Immediately after the backwashing process is finished, foreign substances washed out by the backwashing of the filtration unit 2 remain in the filtration unit 2 or in the pipes of the water treatment device 1 . Therefore, the foreign matter can be discharged by the rinsing process. In this embodiment, the amount of the water-soluble solid chemical 60 used is reduced by not adding the chemical in the rinsing process, but the bypass valve 15 may be closed to add chlorine.

As described above, the chemical supply unit 3 used in the water treatment apparatus 1 having several types of operation modes needs to be switched between the addition and non-addition of the chemical as required. Therefore, by connecting the chemical supply unit 3, which can switch whether or not the chemical agent is added depending on the flow rate, and the bypass pipe 14 that bypasses the chemical supply unit 3, the chemical agent is added during the filtration operation, and is not added during the backwash operation. becomes possible.

(pump/connection piping)
Here, the most characteristic part of the present invention will be described with reference to FIG.

In the water treatment system according to the present embodiment, a water treatment apparatus 1 and an electric pump 4 are connected by a connection pipe 80 , and raw water is sent from the electric pump 4 to the water treatment apparatus 1 through the connection pipe 80 . The connection pipe 80 is arranged so that the connection with the electric pump 4 on the upstream side faces downward and the connection with the water treatment device 1 on the downstream side faces upward. Further, it is preferable that the connecting pipe 80 has a large diameter so that the electric pump 4 and the raw water of the water treatment device 1 can smoothly flow back and forth. For example, the connecting pipe 80 may have a diameter equal to or larger than that of the pipe in the water treatment device 1 . In addition, the electric pump 4 can cause water to flow backward to the water source side by the gravity caused by the height difference between the well and the water treatment device 1 while the electric pump 4 is stopped. That is, valves such as check valves are used from the water source to the electric pump 4, in the electric pump 4, and in the connecting pipe 80 so that the pressure applied to the water treatment apparatus 1 side can be released to the water source side. not Furthermore, the connecting pipe 80 is arranged so that the connecting portion between the connecting pipe 80 and the water treatment apparatus 1 is at the highest position. Moreover, as described above, the chemical supply unit 3 is provided at the highest position in the flow channel inside the water treatment device 1 .

According to such a configuration, when the electric pump 4 stops, the pressure in the connection pipe 80 and the raw water inflow pipe 10 decreases. In the connection pipe 80, since the upstream side is laid downward, the pressure applied to the water in the pipe escapes to the water source side due to the height difference, and at least part of the water flows out. More specifically, when the electric pump 4 stops, the piping system of the water treatment system of the present embodiment is in a water sealed state from the water source side to the purified water discharge piping 20 . Therefore, when the electric pump 4 stops, water corresponding to the pressure applied to the piping system of the water treatment system by the operating electric pump 4 flows out. Therefore, when the pressure in the raw water inflow pipe 10 decreases, the water level in the chemical supply unit 3 arranged at the top of the water treatment device 1 decreases. However, since new air does not flow into the chemical supply unit 3, all the water inside does not flow out and does not fall below a certain water level. is retained.

That is, the pressure applied to the water treatment apparatus 1 during operation can be released from the raw water inflow pipe to the upstream side of the electric pump 4 by the electric pump 4 capable of backflow and the connecting pipe 80 having a large diameter. A certain amount of water is retained in the raw water inflow pipe 10 of the water treatment apparatus 1 .

By reducing the pressure in the water treatment apparatus 1 during the shutdown, the water level in the chemical supply unit 3 is lowered, so that the water-soluble solid chemical 60 does not come into contact with the water, and the concentration of the chemical solution increases. will prevent

The water treatment device 1 also has a check valve 62 on the outlet side of the purified water discharge pipe 20 . That is, when the electric pump 4 stops, there is no forward pressure, and the check valve 62 prevents reverse flow, so the purified water discharge pipe 20 is closed. According to such a configuration, even if the increased pressure in the water treatment apparatus 1 at the time of stoppage falls, the inside of the purified water discharge pipe 20 remains filled with water. Since the water is held in the water treatment apparatus 1 in this manner, the water can be efficiently pumped out when the electric pump 4 is started next time. The check valve 62 is preferably provided below the external pipe leading to the purified water tank 6 .

Since the connection pipe 80 having a large diameter is arranged vertically in this way, the water in the connection pipe 80 is discharged upstream due to the height difference when the electric pump 4 is stopped, and the pressure inside the pipe of the water treatment device 1 is reduced. can be lowered. As a result, the water level in the medicine supply unit 3 is lowered, and the water-soluble solid medicine 60 is not constantly submerged in water, and wasteful outflow of the water-soluble solid medicine 60 can be suppressed.

The water treatment device according to the present invention can supply a sufficient amount of clean backwash water for backwashing, and can be installed in a smaller space than conventional products, so it can be used for purifying well water and stored water. It is useful as a small household water treatment device, etc.

REFERENCE SIGNS LIST 1 water treatment device 2 filtration unit 3 drug supply unit 4 electric pump 5 switching valve 6 purified water tank 10 raw water inflow pipe 11 raw water inlet 12 branching portion 13 branching portion 14 bypass pipe 15 bypass valve 20 purified water discharge pipe 21 purified water outlet 24 throttle portion 31 Inflow path 32 Drug path 33 Bypass path 33a Throttle 34 Outflow path 40 Backwash drain pipe 51 Housing 51a Base 51b Top cover 52 Ejection pipe 53 Drug placement portion 54 Recovery portion 55 Recovery opening 58 Placement portion outlet 60 Water soluble Solid drug 62 Check valve 70 Water collecting pipe 71 Upper layer 72 Lower layer 73 Inlet 74 Outlet 75 Channel switching piece 80 Connection pipe

Claims (4)

a filtration unit containing a filter medium;
A raw water inflow pipe that allows raw water to flow into the filtration unit;
a chemical supply unit that adds a chemical within the route of the raw water inflow pipe;
a water treatment apparatus having a purified water discharge pipe for extracting treated water after filtration from the filtering unit;
a connecting pipe connected to the raw water inflow pipe;
Having an electric pump that sends water to the connection pipe,
The chemical supply unit is arranged above the raw water inflow pipe and the purified water discharge pipe,
A water treatment system in which the connecting pipes are arranged vertically so that the downstream side faces upward. 2. The water treatment system according to claim 1, wherein said connection pipe has a diameter equal to or larger than that of said raw water inflow pipe and said purified water discharge pipe. 3. The water treatment system according to claim 1, wherein a check valve is provided on the outlet side of said purified water discharge pipe. providing a purified water tank for storing purified water flowing out of the water treatment device;
The water treatment system according to any one of claims 1 to 3, wherein the purified water tank is provided above an outlet of the purified water discharge pipe.

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