JP2023131194A - Water treatment device - Google Patents

Abstract

To provide a water treatment device which prevents increase in pressure and a flow rate and performs stable agent supply.SOLUTION: A water treatment device 1 according to the present invention is provided with: a filtration part 2 containing a filter; raw water inflow piping 10 for flow of raw water into the filtration part 2; an agent supply part 3 which adds an agent in a pathway of the raw water inflow piping 10; purified water discharge piping 20 for removal of purified water after filtration from the filtration part 2; and a pressure reducing valve 80 in the raw water inflow piping 10 on an upstream side of the agent supply part 3. A pressure in the raw water inflow piping 10 can be regulated into a desired range, thereby regulating a raw water inflow amount into the agent supply part 3 into a predetermined range. A flow of an excessive water amount into the agent supply part 3 is prevented and thereby a desired water amount and water pressure is applied to the solid agent, enabling supply of a desired concentration of an agent liquid, thus preventing a defined concentration or more of the agent from eluting from the agent supply part 3.SELECTED DRAWING: Figure 1

Description

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

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 device. For example, when purifying well water, it is possible to oxidize the raw water to be purified using a chemical supply device that gradually dissolves solid calcium hypochlorite.

In a system that injects a drug using a metering pump or a drug supply device that elutes a fixed amount of drug regardless of the flow rate, the drug concentration decreases when the flow rate increases.

As shown in FIG. 6, in the solid drug supply device 101, raw water is introduced from the water intake port 102 to contact the water-soluble solid drug 103, and when the flow rate increases within a certain range, the water enters the drug contact phase 104. It is possible to increase the amount of water-soluble solid drug 103 brought into contact with the water level. With this mechanism, even when the flow rate increases, the amount of drug elution increases, making it possible to suppress a decrease in drug concentration (for example, see Patent Document 1).

Publication No. 58-49836

In such water treatment equipment, it is necessary to adjust the amount of chemicals added to obtain a chemical solution with a desired concentration. In particular, it is desired that a drug solution of a desired concentration can be obtained with a simple configuration.

Therefore, the present invention solves the above-mentioned conventional problems, and prevents excessive water flow and pressure from being applied to the solid drug supply device by controlling the water pressure or water amount inside the raw water inflow pipe inside the water treatment device. It is an object of the present invention to provide a water treatment device that can obtain a chemical solution with a desired concentration by restricting the water pressure and water flow of raw water in which a chemical is immersed.

In order to achieve this object, the water treatment device according to the present invention includes a filtration part that includes a filter medium, a raw water inflow pipe that allows raw water to flow into the filtration part, and a chemical agent within the route of the raw water inflow pipe. It has a medicine supply section for adding, a purified water discharge pipe for taking out purified water after filtration from the filtration part, and a pressure reducing valve provided on the upstream side of the medicine supply part in the raw water inflow pipe, and the pressure reducing valve is provided. The desired purpose is achieved by a configuration in which the pressure in the raw water inflow pipe can be adjusted within a desired range in order to suppress elution of a drug with a concentration higher than a specified concentration from the drug supply section. .

According to the present invention, in a water treatment device, by adjusting the pressure in the raw water inflow pipe within a desired range, the amount of water during filtration treatment can be controlled within a desired range, thereby reducing the amount of water to the chemical supply section. The amount of raw water inflow can be adjusted within a predetermined range. By setting the water level in the drug supply section to a desired height, there is an effect that the elution amount of the drug can be suppressed to a desired value.

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

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
The water treatment device 1 according to the present embodiment uses well water or water stored in a water storage tank as raw water, and performs a filtration process to remove metal ions and turbid components contained in this raw water, and a filtration process to remove metal ions and turbid components that are accumulated in the system. This process performs a backwashing process to discharge aggregated metal ions and turbid components out of the system.

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

As shown in FIG. 1, the water treatment device 1 includes a filtration section 2 that includes a filter medium, and a drug supply section 3 that adds a drug to raw water. It is constructed by connecting it with piping. The filtration unit 2 purifies the raw water by removing metal ions and suspended matter components from the raw water, and is, so to speak, the heart of the water treatment device 1 . Dirt accumulated in the filtration section 2 is discharged from the device through backwashing and rinsing, thereby keeping the filtration section 2 clean and enabling repeated use. The backwashing process is a process of flowing raw water in a backward direction within the filtration unit 2 to discharge dirt (FIG. 2). In the rinsing process, after backwashing process is performed, raw water is flowed in the filtration direction into the filtration section 2 to discharge the separated dirt to the outside of the apparatus (FIG. 3). For this filtration part 2, the pipe that sends the raw water is called the raw water inflow pipe 10, and the pipe that sends out the water purified by the filtration part 2 from the filtration part 2 is called the purified water discharge pipe 20. The pipe for discharging dirt is referred to as a backwash drain pipe 40. The purified water is stored in a purified water tank 6 or the like provided outside the water treatment device 1, and is used as domestic water when needed.

Raw water is sent to the water treatment device 1 by an electric pump 4 connected to the inlet side of the raw water inflow pipe 10 (on the opposite side of the filtration section 2). Note that instead of using the electric pump 4, a water storage tank storing raw water may be provided at a high place, and the raw water may be sent to the water treatment device 1 based on the height difference between the water storage tank and the water treatment device 1. Alternatively, tap water jointly operated in the region may be directly connected. In this embodiment, in addition to wells, water tanks, tap water, and the like, water sources include devices that send out raw water.

The electric pump 4 is a pump driven by an electric motor that sucks up and discharges water stored in a well or a water tank, and includes, for example, a centrifugal pump such as a centrifugal pump or a turbine pump, a vortex pump (cascade pump), a jet pump, Axial flow pumps, mixed flow pumps, etc. are used. Also, if the water level in the well is low, it is better to use a submersible pump, such as a submersible pump, instead of a suction type pump. When used in a general household, the depth of the well must be approximately 1 to 10 meters for shallow wells, and 10 to 30 meters for deep wells. Considering the head loss of downstream piping and water treatment equipment, a pump with a lift 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, but for general household use, it is more preferable to have a flow rate characteristic of about 5 liters to 50 liters per minute.

The raw water inflow pipe 10 and the purified water discharge pipe 20 may be made of any material or structure as long as they can withstand the water pressure of the electric pump 4. Specifically, from the viewpoint of durability and ease of processing, for example, straight pipes and pipe joints made of vinyl chloride resin, steel pipes, or composite materials thereof can be used. In addition, the nominal diameter is preferably large so as to reduce the head loss, for example, the nominal diameter is preferably 13 to 50 mm, and the thickness is preferably about 1 to 5 mm. If it is difficult to select a member that can withstand the maximum pressure of the electric pump 4, a pressure reducing valve, a pressure regulating valve, or a relief valve may be installed between the electric pump 4 and the water treatment device 1.

The drug supply section 3 is provided within the path of the raw water inflow pipe 10. The chemical supply section 3 functions to add an oxidizing agent to the raw water, to aggregate metal ions contained in the raw water into substances that are hardly soluble in water, and to make them easier to collect in the filtration section 2 .

(filtration section)
Next, the filtration part 2 and the switching valve 5, which are parts related to the filtration part, will be explained using FIG. 4.

The filtration section 2 has a filter material and a water collection pipe 70 therein, and is used to purify raw water by passing it therethrough. The filter medium inside the filter section 2 is composed of an upper layer 71 mainly for filtering dirt and a lower layer 72 having a rectifying effect. The filter medium used for the upper layer 71 is activated carbon, manganese sand, anthracite, etc., and one to four types are used in layers depending on the quality of the raw water. In the filtration section 2 of this embodiment, the filtration action is centered around this upper layer 71. The filter medium used in the lower layer 72 is made of gravel, resin with coarse holes, etc. for dispersing water flowing in and out of the water collection pipe. In the lower layer 72, a gravel layer with relatively large particle size is provided at the lowest layer to improve the flow of water and to prevent the filter medium from flowing out from the lower part of the water collection pipe 70. The amount of filter material in the lower layer 72 is preferably about 1/2 to 1 times the diameter of the filter section 2. Further, the total filling amount of the filter media in the upper layer 71 and the lower layer 72 is preferably about 1/4 to 4/5 times the internal volume of the filtration section 2.

The filtration unit 2 is connected to external pipes (raw water inflow pipe 10, purified water discharge pipe 20, backwash drain pipe 40) at the upper part. An inlet 73 and an outlet 74 are provided inside the filtration part 2, and the outlet 74 is connected to the water collection pipe 70.

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

During the filtration process, by operating the flow path switching piece 75, the raw water inflow pipe 10 and the inlet 73, and the outlet 74 and the purified water discharge pipe 20 are made to communicate with each other. On the other hand, during backwash processing, by operating the flow path switching piece 75, the raw water inflow pipe 10 and the outflow port 74, and the inflow port 73 and the backwash drain pipe 40 are made to communicate with each other. Further, during the rinsing process, by operating the flow path switching piece 75, the raw water inflow pipe 10 and the inlet port 73, and the outlet port 74 and the backwash drain pipe 40 are made to communicate with each other.

Note that various operations are possible depending on the type of piping connected to the switching valve 5. For example, raw water can be directly sent 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 path can be switched by using a plurality of valves other than the switching valve 5.

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

[Flow path in filtration section 2 during filtration process]
Inflow port 73 → Upper layer 71 → Lower layer 72 → Water collection pipe 70 → Outlet port 74
Note that during the rinsing process, water flows in the filtration section 2 in the same manner as during the filtration process, but water containing dirt after the backwash process described below flows out from the outlet 74. Therefore, the outflow port 74 is communicated with the backwash drain pipe 40 and discharged to the outside.

Furthermore, dirt accumulated in the filtration unit 2 during the filtration process can be discharged by backwashing process. During the backwash process, water flows as shown below and dirt is discharged from the outlet 74.

[Flow path in filtration section 2 during backwashing process]
Outlet 74 → Water collection pipe 70 → Lower layer 72 → Upper layer 71 → Inlet 73
(Drug supply department)
As shown in FIG. 5, the drug supply section 3 is provided to promote the aggregation of metal ions contained in the raw water by the drug contained therein, and to make it easier to capture the metal ions in the filtration section 2. The drug supply section 3 has an inflow path 31, a drug path 32, a bypass path 33, and an outflow path 34. The inflow path 31 is connected to the raw water inflow pipe 10 and causes raw water to flow into the drug supply section 3 . The drug path 32 branches from the inflow path 31 and dissolves the drug. The bypass passage 33 is provided with a constriction part 33a, which also branches from the inflow passage 31, to adjust the concentration of the chemical solution to a required concentration. The bypass path 33 is connected to the inlet side of the outflow path 34 after branching from the inflow path 31 . The outflow path 34 merges with the drug path 32 and the bypass path 33, connects again to the raw water inflow pipe 10, and sends raw water containing chemicals to the raw water inflow pipe 10. As shown in FIG. 5, the drug path 32 includes an ejection pipe 52 that rises vertically after branching, a drug mounting portion 53 that contacts the drug at the upper part of the ejection pipe 52 and elutes the drug, and It is composed of a collecting section 54 located on the outer periphery and inside the casing 51.

The ejection pipe 52 is a small-diameter conduit and is erected with a medicine placement part 53 at the top. By reducing the diameter of the lower part of the ejection pipe 52 and providing the medicine placement part 53 at the upper part of the ejection pipe 52, it is possible to bring the raw water into contact with the medicine at a desired flow rate. The drug placement section 53 has a size that ensures the amount (number) of drugs to be placed so that a drug solution with a desired concentration can be obtained with respect to the flow rate of raw water.

The drug solution in which the drug is dissolved flows out to the recovery section 54. In the recovery section 54 , the drug solution containing the drug is collected in the lower part of the casing 51 , and then flows out from the recovery 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 raw water containing the drug that has flowed down into the housing 51 has a liquid level relative to the height of the housing 51. , about 1/2 or less. By accumulating the chemical solution in the housing 51 at a desired depth, the ratio of mixing with the raw water in the outflow path 34 is adjusted.

Further, the flow rate of raw water flowing through the drug path 32 can be adjusted by adjusting the flow rate of raw water flowing through the bypass path 33. That is, by adjusting the diameter of the constricted portion 33a of the bypass path 33, the flow rate ratio of raw water flowing through the drug path 32 and the bypass path 33 is adjusted. In this way, the drug concentration in the outflow path 34 after the merger can be adjusted to a desired concentration. Note that the flow rate of raw water flowing through the bypass path 33 may be adjusted using a flow rate adjustment valve instead of the throttle part 33a.

The medicine placement section 53 is equipped with a water-soluble, solid medicine 60. As the drug 60, it is preferable to use a tablet or granule. This is because the surface area of the drug 60 can be increased and a stable drug concentration can be maintained. If it is a tablet, it is recommended to use one with a diameter of about 30 mm and a height of 10 to 20 mm, and if it is in the form of granules, one with a diameter of 5 mm to 15 mm should be used. If the size of the medicine 60 is small, adjacent medicines will come into contact with water at the same time and will stick to each other. If the drug sticks, only the lower part of the drug may come into contact with water, making it impossible to obtain a drug solution with the desired concentration. Alternatively, if the size of the drug 60 is small, the area of contact with the water supplied from the ejection tube 52 becomes large, making it impossible to obtain a drug solution with a desired concentration. Therefore, in order to supply a drug solution with a desired concentration, the drug 60 of the above-mentioned size is used.

Further, as described above, the chemical 60 functions to oxidize metal ions contained in raw water to generate aggregates that are hardly soluble in water. Various oxidizing agents can be used as the chemical 60, but depending on the required water purification performance, an inorganic flocculant or a polymer flocculant such as PAC (polyaluminum chloride) or chitosan may be used. When adding a chemical to raw water, the chemical 60 should preferably be easily soluble in water, but during suspension or backwashing, that is, when the addition of the chemical is interrupted, the chemical 60 should remain solid. , one that does not flow out from the drug placement section 53 is preferable. In this embodiment, trichloroisocyanuric acid is used.

Note that it is preferable that an air layer always exist within the casing 51 of the drug supply section 3. Since the casing 51 is a closed space except for the connection part with the raw water inflow pipe 10, once the air is gone and the inside of the casing 51 is filled with water, the drug 60 will constantly come into contact with the water and continue to elute. . The water treatment device 1 of this embodiment is configured to allow air to enter when the lid 35 of the chemical supply section 3 is removed. The operation of removing the lid part 35 of the drug supply section 3 is performed mainly when replenishing the drug 60 that has been gradually reduced by being eluted into the raw water. Further, although the details will be described later, the flow path during backwash processing is connected to a backwash drain pipe 40, and the backwash drain pipe 40 is open to the outside air in order to discharge water out of the system. . By opening to the outside air, water accumulated in the casing 51 is discharged, and at the same time, air flows in to maintain an air layer within the casing 51. In addition, air can be sent to the drug supply section 3 by attaching an air supply pipe or a valve such as a check valve to the raw water inflow pipe 10.

Each member of the drug supply section 3 may be in contact with the drug for a long time, so it is best to choose materials that have low reactivity to the drug, such as PVC (polyvinyl chloride), PMMA (polymethyl methacrylate), and PP (polypropylene). . On the other hand, since the ejection pipe 52 needs strength to support the drug placement part 53, considering its compatibility with the drug, the material of the ejection pipe 52 is vinyl chloride or ABS (acrylonitrile-butadiene-styrene), which is stronger than PP. It is preferable to select The outer diameter of the ejection pipe 52 is preferably suppressed to one-fourth or less of the inner diameter of the base 51a and the upper cover 51b. As described above, a space (recovery section 54) can be provided outside the ejection pipe 52 to temporarily store the solution discharged from the placement section outlet 58 after supplying the medicine, so that the water level in the housing 51 can be prevented from rising rapidly. This is because it is possible to prevent the medicine from rising and reaching the medicine placement part 53. For example, if the inner diameter of the base 51a is 130 mm, it is preferable to use a PVC pipe or the like with an outer diameter of about 25 to 40 mm.

(Piping configuration)
As described above, as shown in FIGS. 1 to 3, the water treatment device 1 of the present embodiment includes the filtration section 2, the raw water inflow pipe 10, the purified water discharge pipe 20, and the backwash drain pipe 40. . The raw water inflow pipe 10 has an inlet side connected to a discharge port of an electric pump 4 serving as a water source, and an outlet side connected to a switching valve 5 of the filtration section 2 . A drug supply section 3 is provided in the path of the raw water inflow pipe 10, and a bypass pipe 14 that bypasses the drug supply section 3 is further provided. This bypass pipe 14 branches at the raw water inflow pipe 10 on the upstream side of the drug supply section 3 (first branch section 12), bypasses the drug supply section 3, and connects the raw water inflow pipe 10 on the downstream side of the drug supply section 3. (second branch 13). Further, a bypass valve 15 is provided to adjust the flow rate flowing through the bypass pipe 14. In other words, the bypass valve 15 is capable of adjusting the flow rate flowing through the bypass valve 15 (opening or closing the water channel within the bypass valve 15).

The filtration unit 2 has two outlets, and one outlet is connected to a purified water discharge pipe 20 for taking out purified water inside. The other outlet is connected to a backwash drain pipe 40 that discharges particulate matter (dirt, turbid components, metal aggregates, etc.) collected in the filtration section 2 out of the system during backwash processing and rinsing processing. has been done.

Next, the piping configuration within the water treatment apparatus 1 and the flow of water in the filtration process and the backwash process will be explained using FIGS. 1 to 4. 4 is a schematic cross-sectional view of the filtration unit 2, FIG. 4(a) is an overall view during filtration processing, FIG. 4(b) is the state of the switching valve 5 during backwash processing, and FIG. 4(c) is a rinsing It shows the state of the switching valve 5 during processing.

First, the flow of water during filtration processing will be explained using FIG. 1 and FIG. 4(a).

During the filtration process, the bypass valve 15 is closed, and the raw water inflow pipe 10 is connected from the raw water inlet 11 on the water source side to the filtration part 2 via the drug supply part 3. In the filtration section 2, the switching valve 5 is operated to switch the connection so that the raw water inflow pipe 10 and the inlet 73 communicate with each other, and the outlet 74 and the purified water discharge pipe 20 communicate with each other.

A constriction section 24 is provided in the path of the purified water discharge pipe 20. This is because, in order to obtain the desired filtration performance, it is necessary to suppress the flow rate during the filtration process so that the flow rate is set according to the capacity of the filtration unit 2.

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

[Flow path during filtration process]
Raw water inlet 11 → (raw water inflow pipe 10) → first branch part 12 → medicine supply part 3 → second branch part 13 → switching valve 5 → filtration part 2 → switching valve 5 → (purified water discharge pipe 20) → purified water outlet 21
Note that a check valve 62 is provided in the path of the purified water discharge pipe 20. Purified water taken out from the purified water outlet 21 is often piped and connected to a purified water tank 6 provided at a high place. The check valve 62 prevents the backflow of purified water from the purified water tank 6 provided at a high place, and prevents the water from flowing back into the filtration section 2 .

Next, the flow of water during backwash processing will be explained using FIG. 2 and FIG. 4(b).

During the backwash process, the bypass valve 15 is opened, and the raw water inlet pipe 10 is connected to the filtration unit 2 by communicating with the bypass valve 15 from the raw water inlet 11 on the water source side via the bypass pipe 14. In the filtration section 2, the switching valve 5 is operated to switch the connection so that the raw water inflow pipe 10 and the outflow port 74 communicate with each other, and the inflow port 73 and the backwash drain pipe 40 communicate with each other.

At this time, the flow of water in the filtration section 2 is reversed from that during the filtration process. In the water treatment device 1 according to the present embodiment, by switching the switching valve 5 and the bypass valve 15, the water source (electric pump 4) can be used as one, and filtration processing and backwashing processing can be performed.

During backwashing, water flows as shown below.

[Flow path during backwashing process]
Raw water inlet 11 → (raw water inflow pipe 10) → first branch part 12 → (bypass pipe 14) → bypass valve 15 → (bypass pipe 14) → second branch part 13 → switching valve 5 → filtration part 2 → switching valve 5 →Backwash drain pipe 40
In this way, during the backwashing process, after passing through the filtration section 2, it is discharged outside the apparatus, so there is no need to aggregate metal ions and the like by adding chemicals. Therefore, during the backwash process, raw water is sent to the filtration unit 2 via the bypass pipe 14 that bypasses the drug supply unit 3. During the backwashing process, the elution of chemicals is suppressed, and the water is supplied to the filtration section 2 in a state similar to raw water, and the inside of the filtration section 2 is cleaned.

Note that the water treatment apparatus 1 of the present embodiment can perform a "rinsing process" for discharging foreign matter remaining in the pipes during the backwash process. This rinsing process will be explained using FIG. 3 and FIG. 4(c). The rinsing process can be performed by changing the flow path of the switching valve 5. The switching valve 5 switches the raw water inflow pipe 10 and the inlet 73 to communicate with each other, and the outflow port 74 and the backwash drain pipe 40 to communicate with each other. In this state, water flows in the filtration section 2 in the same direction as the filtration process, and the water that has passed through the filtration section 2 is discharged through the backwash drain pipe 40. In addition, since the water is discharged from the large-diameter backwash drain pipe without passing through the throttle part 24, the pressure inside the raw water inflow pipe 10 becomes as low as during backwash processing, and the bypass valve 15 remains open. Become.

By operating these valves, water will flow as follows during the rinsing process.

[Flow path during rinsing process]
Raw water inlet 11 → (raw water inflow pipe 10) → first branch part 12 → (bypass pipe 14) → second branch part 13 → switching valve 5 → filtration part 2 → switching valve 5 → backwash drain pipe 40
Immediately after the backwashing process is finished, foreign matter washed out by the backwashing of the filtration part 2 remains in the filtration part 2 or in the piping of the water treatment device 1. Therefore, foreign matter can be removed by rinsing.

Next, the most characteristic part of this embodiment will be explained. As shown in FIGS. 1 and 5, the water treatment device 1 of this embodiment includes a pressure reducing valve 80 in the path of the raw water inflow pipe 10 on the upstream side of the chemical supply section 3. The flow pressure within can be adjusted within a desired range.

The medicine supply unit 3 includes a hollow housing 51, a cylindrical ejection pipe 52 provided inside the housing 51 and rising vertically, and a medicine placement part provided above the ejection pipe 52 in which a medicine 60 can be placed. 53, and a recovery section 54 provided on the outer periphery of the ejection pipe 52. The raw water flowing through the raw water inflow pipe 10 enters the casing 51 via the ejection pipe 52, comes into contact with the medicine 60, collects in the collection part 54, and flows from the collection part 54 to the raw water inflow pipe 10. A portion of the drug 60 is immersed in the water flowing from the ejection pipe 52, and a portion of the drug 60 is exposed to the air layer within the housing 51.

According to this configuration, when it is assumed that the well water level fluctuates widely and the pressure inside the water treatment device 1 also fluctuates greatly, the raw water inflow piping is particularly affected by water pressure changes in the piping connected to the water supply. The pressure inside 10 may become high and exceed a predetermined value. When high-pressure raw water is supplied to the water treatment device 1, the air layer exists in the casing 51 of the drug supply unit 3, and the drug The air present in the supply section 3 is compressed, the water level inside the drug supply section 3 rises, and the drug 60 having a specified concentration or more may be eluted.

In this way, when high pressure is applied to the raw water inflow pipe 10, as shown in FIG. 1, the pressure reducing valve 80 operates the valve when raw water with a predetermined pressure higher than the predetermined pressure set by the pressure reducing valve 80 flows from the upstream side. A predetermined pressure can be maintained in the piping downstream of the pressure reducing valve 80. By adjusting the pressure inside the raw water inflow pipe 10 within a desired range, the amount of water during filtration processing can be controlled within a desired range, thereby keeping the amount of raw water flowing into the chemical supply section 3 within a predetermined range. Can be adjusted. By suppressing an excessive amount of water from flowing into the drug supply section 3, a desired amount of water and water pressure can be applied to the solid drug, and a drug solution with a desired concentration can be supplied.

Then, the amount of raw water flowing from the raw water inflow pipe 10 through the inflow path of the medicine supply section 3 to the ejection pipe 52 is made to fall within a predetermined range. Since the outer diameter of the ejection pipe 52 is made small to secure the volume inside the casing, the amount of elution of the drug can be suppressed to the desired value by setting the water level in the drug supply section 3 to the desired height. . Therefore, the concentration of the chemical solution in the raw water flowing out from the drug supply section 3 can be adjusted to a desired concentration.

Moreover, since the pressure reducing valve 80 can reduce the pressure of the raw water flowing in to a certain level or less, the filtration flow rate and the backwash flow rate of the water treatment device 1 can be adjusted to within specified values.

Specifically, during the filtration process, the piping is connected from the raw water inflow piping 10 to the filtration part 2 via the chemical supply part 3, and by switching the switching valve 5, the raw water is connected to the filtration part 2 via the throttle part 24 and the purified water discharge piping 20. However, there is a route for sending purified water to the purified water tank 6. Since the constriction section 24 has a portion whose diameter is smaller than that of other piping, the flow rate during the filtration process is suppressed. The combination of the throttle section 24 and the electric pump 4 allows the flow rate during the filtration process to be set to a desired design value. In the path passing through the constriction section 24, pressure loss in the piping is greater than in the path during backwash processing, and the pressure in the raw water inflow piping 10 tends to increase. Here, when the pressure in the raw water inlet pipe 10 increases and exceeds a predetermined pressure, the pressure reducing valve 80 can reduce the pressure in the raw water inlet pipe 10 to a certain level or less. The amount of raw water flowing into the drug supply section 3 can flow within a predetermined range and be connected to the filtration section 2, so that the raw water can flow within a predetermined range of the filtration flow rate.

On the other hand, as shown in FIG. 2, backwashing requires a large flow rate. That is, the flow rate during the filtration process is made smaller than the flow rate during the backwash process. As mentioned above, for the piping during the backwash process, the switching valve 5 is switched so that the raw water inflow pipe 10 is connected to the filtration unit 2 via the bypass pipe 14 and communicated with the backwash drain pipe 40. . Therefore, by increasing the diameter of the bypass piping 14, the pressure loss in the bypass piping 14 is small, so that all the raw water flows into the bypass piping 14 without passing through the drug supply section 3 side, and the bypass piping 14 is It is designed to ensure a flow rate of water passing through.

During backwash processing, the chemical supply section 3 does not pass through, there is no part with a reduced diameter such as the throttle section 24, and the pressure reducing valve 80 can reduce the pressure of the inflowing raw water below a certain level, so the filtration processing It is possible to secure a larger flow rate than usual and perform backwash processing efficiently. Note that the backwash drain pipe 40 has a larger diameter than the constricted portion 24 in order to directly discharge the large flow rate during the backwash process. Further, during the backwashing process, since raw water does not flow through the chemical supply section 3, the chemical is also prevented from coming into contact with water.

In this manner, the pressure reducing valve 80 can adjust the filtration flow rate and the backwash flow rate within specified values by adjusting the pressure of the raw water inflow pipe within a desired range.

The water treatment device according to the present invention can supply a chemical solution with a stable concentration and has stable filtration performance, so it is useful as a small household water treatment device used for purifying well water or stored water. It is.

1 Water treatment device 2 Filtration part 3 Chemical supply part 4 Electric pump 5 Switching valve 6 Purified water tank 10 Raw water inflow pipe 11 Raw water inlet 12 First branch part 13 Second branch part 14 Bypass pipe 15 Bypass valve 20 Purified water discharge pipe 21 Purified water outlet 24 Restriction section 31 Inflow path 32 Drug path 33 Bypass path 33a Restriction section 34 Outflow path 40 Backwash drain pipe 51 Housing 51a Base 51b Upper cover 52 Ejection pipe 53 Drug placement section 54 Recovery section 55 Recovery opening 58 Placement section Outlet 60 Medicine 62 Check valve 70 Water collection pipe 71 Upper layer 72 Lower layer 73 Inflow port 74 Outflow port 75 Flow path switching piece 80 Pressure reducing valve

Claims (3)

A filtration part containing a filter medium;
a raw water inflow pipe that allows raw water to flow into the filtration section;
a chemical supply unit that adds a chemical within the route of the raw water inflow piping;
purified water discharge piping that takes out the filtered treated water from the filtration section;
The raw water inflow pipe includes a pressure reducing valve provided upstream of the drug supply section,
The water treatment device is characterized in that the pressure reducing valve adjusts the pressure within the raw water inflow pipe within a desired range in order to suppress the elution of a drug with a concentration higher than a specified concentration from the drug supply section. The drug supply section includes:
A hollow casing;
a cylindrical ejection pipe provided in the housing and rising vertically;
a drug placement part provided at the top of the ejection tube and capable of placing the drug;
a recovery part provided on the outer periphery of the ejection pipe,
The raw water flowing through the raw water inflow pipe enters the casing via the ejection pipe, comes into contact with the drug, collects in the recovery part, and flows from the collection part to the raw water inflow pipe. 1. The water treatment device according to 1. Within the route of the raw water inflow piping, it branches at a first branch between the pressure reducing valve and the drug supply section, and the raw water flows at a second branch between the drug supply and the filtration section. Bypass piping that joins the inflow piping;
a bypass valve in the bypass piping route;
a backwash drain pipe for flowing wastewater from the filtration section;
a constriction part in the path of the purified water discharge piping;
a switching valve that switches communication connection between the raw water inflow pipe, the purified water discharge pipe, the backwash drain pipe connected to the filtration part, and an opening in the filtration part;
During the filtration process, the bypass valve is closed and the filtration section and the purified water discharge pipe are communicated,
3. The water treatment apparatus according to claim 1, wherein during backwash processing, the bypass valve is communicated with the filtration section and the backwash drain pipe.