JPWO2009116479A1 - Water treatment equipment water supply pipe cleaning method - Google Patents

Abstract

Washing the water supply piping of the water treatment device that allows the water supply piping of the filter to be washed sufficiently and enables filtration to continue for a long period of time, even if it is a filter used to filter organic-containing water that is prone to microbial growth Method. Compressed air is injected into the water supply pipe (12) from the air injection pipe (16), and a gas-liquid mixed water of raw water and air is supplied to the water supply pipe (12) for air cleaning, and cleaning wastewater is supplied from the pipe (17). Discharge. Then, backwashing is performed according to a conventional method. The portion of the pipe (13) that cannot be cleaned during air cleaning is cleaned by backwashing after air cleaning.

Description

Field of Invention

  The present invention relates to a method for cleaning a water treatment apparatus water supply pipe, and in particular, a method for efficiently washing a water treatment apparatus water supply pipe such as a filtration apparatus for filtering organic substance-containing water that contains a large amount of organic matter and easily proliferates with microorganisms. About.

Invention of the invention

  The filtration device captures and removes impurities such as SS from the filter bed formed by filling the filter with sand, anthracite, and other filter media. A filtration operation in which treated water is obtained by passing water and backwashing in which backwashing water is introduced into the filter and SS or the like captured by the filter bed is discharged are alternately performed (for example, Patent Document 1).

  When filtering raw water that contains a lot of organic matter and easily proliferates with such a filtration device, microorganisms contained in the raw water and captured in the filter bed, or microorganisms grown in the filter bed, should be washed back. Washed away.

  However, the microorganisms that have grown and adhered to the raw water supply pipe from the raw water tank to the filter are not washed away by backwashing, but as a result of the microorganisms growing over time, the water supply pipe is blocked or attached to the pipe. Microorganisms clump into the filter. The clogging of the pipe itself is also a serious problem, but when a microbial mass separated from the pipe flows into the filter, it is difficult to discharge by normal backwashing because its specific gravity is close to that of the filter medium. Then, as a result of forming a mud ball with the viscous material produced by the microorganisms accumulated in the filter and the filter medium, the filter performance is reduced due to the clogging of the filter bed and the short path of the filter medium.

In order to solve these problems, conventionally, it has been widely practiced to prevent the growth of microorganisms by injecting a drug having a bactericidal effect into raw water. Furthermore, pipe maintenance and filter media replacement are performed as regular maintenance work.
Japanese Patent No. 3460324

  Conventional sterilization with chemicals requires complicated daily work, such as adjusting and replenishing the amount of chemicals to be injected; handling harmful chemicals is undesirable in terms of the work environment; requires chemical costs, especially the amount of water to be treated is large Then, the cost of chemicals also rises; there is a possibility that chemicals may be mixed into the filtered water, so when using the filtered water, it is necessary to provide a means for removing the chemicals or to rinse with a large amount of water after chemical cleaning. There is a problem that there is;

  In addition, pipe cleaning and replacement of filter media as periodic maintenance operations are not preferable in terms of operating efficiency because it is necessary to stop the operation of the filtration device. In addition, the amount of work and the cost of the filter medium are problematic.

  Therefore, there is a demand for a method of cleaning the water supply piping of the filter without sterilization with such chemicals or maintenance work with the operation of the filtration device stopped.

  In addition, the method described in Patent Document 1 is a combination of backwashing with air and backwashing with an alkali and / or acid. In addition to the need for alkali and / or acid, backwashing water is Since the water flows in the reverse direction in the filter and is discharged from the filter, the water supply pipe cannot be washed.

  The above-mentioned problems related to cleaning of water supply pipes are not limited to filtration devices, and practically, the filtration function is provided by water treatment materials such as ion exchange resins and activated carbon, such as ion exchangers, water softeners, and activated carbon towers. It is a problem common to all devices that are played and backwashed regularly or as needed.

  The present invention solves the above-mentioned conventional problems, can sufficiently wash the water supply piping of a water treatment device such as a filtration device, and even when used for treatment of organic matter-containing water in which microorganisms are likely to grow, It is an object of the present invention to provide a water treatment apparatus water supply pipe cleaning method capable of stably continuing treatment over a long period of time.

  The water treatment apparatus water supply pipe cleaning method of the present invention (Claim 1) includes a water treatment apparatus main body filled with a water treatment material and backwashed periodically or as necessary, and the water treatment apparatus main body. Water supply pipe for supplying raw water to the main body, treated water pipe for extracting treated water from the main body of the water treatment apparatus, backwash water pipe for supplying backwash water to the main body of the water treatment apparatus, and discharge of backwash wastewater to the outside of the system In the method of cleaning the water supply pipe of the water treatment apparatus having the backwash drainage pipe connected to the water supply pipe, the air mixed water is located upstream of the connection portion between the backwash drainage pipe and the water supply pipe. An air washing step of discharging the mixed water from the backwash drainage pipe through the connecting portion, and then supplying backwash water to the water treatment device main body. Backwashing process for discharging backwashing drainage from the backwashing drainage pipe through the connecting portion. Characterized by washing the water supply pipe by

In the present invention, the amount of air injected into the water supply pipe in the air cleaning step is 4 to 10 L / min per 1 cm ² of the cross-sectional area of the water supply pipe, and the cleaning time of the air cleaning process is expressed by the following formula (I 3) or more than the reference time T (minutes) calculated in (2).
T = {S × L × 0.001 / W} (I)
(However, S is the cross-sectional area (cm ² ) of the water supply pipe, L is the length (cm) of the water supply pipe through which the air-mixed water flows, and W is the water flow rate (L / min) during cleaning.)

  Further, after the backwashing step, a final cleaning step of supplying raw water to the water treatment device main body through the water supply pipe and discharging outflow water from the water treatment device main body out of the system may be performed. Item 3).

  Furthermore, you may perform the process water piping air washing | cleaning process which supplies mixed water to a treated water piping, and discharges | emits out of the system (Claim 4).

  Further, in the case of having a treated water tank for storing treated water from the treated water pipe and a backwash water pipe for supplying treated water in the treated water tank as backwash water to the water treatment device main body, prior to the backwash process. Further, a backwash water pipe air washing step of supplying air mixed water to the backwash water pipe and discharging it outside the system may be performed (Claim 5). In this case, the backwash water pipe is connected to the water treatment device main body. If the device is structured to be connected to the treated water pipe in the vicinity of the treated water discharge port, the mixed water is supplied from the backwash water pipe to the treated water pipe through the connection between the backwash water pipe and the treated water pipe. In addition, a backwash water pipe and a treated water pipe air washing step for discharging water to the outside of the system after passing the water in the treated water flow direction may be performed.

In the present invention, the water treatment apparatus main body includes the following (claims 7 to 10).
(1) Filter with a filter medium filled as a water treatment material
(2) Ion exchange tower filled with ion exchange resin as water treatment material
(3) Water softener filled with ion exchange resin as water treatment material
(4) Activated carbon tower filled with activated carbon as water treatment material

  Such a water treatment apparatus water supply pipe cleaning method of the present invention can be applied to, for example, cleaning of a water supply pipe of a water treatment apparatus using organic substance-containing water as raw water (claim 11).

  In the water treatment apparatus water supply pipe cleaning method according to the present invention, in the air cleaning process, the upstream side of the connection part of the backwash drainage pipe of the water supply pipe is washed with air mixed water and adhered to the inner wall of the pipe It is possible to efficiently remove and wash contaminants such as the like and discharge them from the backwash drainage pipe outside the system. In this air cleaning process, the air-mixed water flows only to the connection part of the backwash drainage pipe of the water supply pipe, and the water supply pipe from this connection part to the water treatment apparatus main body is not cleaned. The length of the pipe from this connection part to the main body of the water treatment device is short, and the necessity for washing of this part is low, but impurities such as microorganisms peeled off during air washing flow into this part, and further the water treatment apparatus There is a risk of flowing into the body.

  In the present invention, after this air cleaning step, backwash water is supplied to the water treatment device main body, and the backwash drainage from the water treatment device main body is discharged from the backwash drainage pipe through the connecting portion. By performing the process, the water supply pipe between the filter body and the connection part and the inside of the water treatment apparatus body can be washed, and contaminants such as microorganisms separated into the part flow into the part during air washing. However, this can be effectively discharged out of the system through the backwash drainage pipe.

In the present invention, the amount of air injected into the water supply pipe in the air cleaning step is 4 to 10 L / min per 1 cm ² of the cross-sectional area of the water supply pipe, and the cleaning time in the air cleaning process is calculated by the following formula (I). When the reference time T (min) is 3 times or more, more efficient cleaning can be performed and a high cleaning effect can be obtained (claim 2).
T = {S × L × 0.001 / W} (I)
(However, S is the cross-sectional area (cm ² ) of the water supply pipe, L is the length (cm) of the water supply pipe through which the air-mixed water flows, and W is the water flow rate (L / min) during cleaning.)

  In addition, after the backwash process, by performing a final cleaning process in which raw water is supplied to the main body of the water treatment apparatus via the water supply pipe and the effluent water from the main body of the water treatment apparatus is discharged out of the system, High-quality treated water can be obtained (claim 3).

  In addition, the treatment water pipe air washing process that supplies air mixture water to the treatment water pipe and discharges it outside the system periodically or as needed further removes contaminants such as microorganisms in the treatment water pipe. Cleaning can be performed (Claim 4).

  Further, in the case of having a treated water tank for storing treated water from the treated water pipe and a backwash water pipe for supplying treated water in the treated water tank as backwash water to the water treatment device main body, prior to the backwash process. The backwash water pipe supplies air mixed water to the backwash water pipe and discharges it outside the system. Contaminants in the pipe can be prevented from flowing into the water treatment apparatus main body together with the backwash water in the backwash process (Claim 5).

  In the washing process of the backwash water pipe, the air mixed water is passed from the backwash water pipe to the treated water pipe through the connecting portion of the treated water pipe and the backwash water pipe, and then discharged out of the system. The treated water pipe can be washed together with the backwash water pipe (Claim 6).

It is a systematic diagram of the filtration apparatus which shows embodiment of the washing | cleaning method of the water treatment apparatus water supply piping of this invention. It is a figure explaining the air washing process 1 (water supply piping air washing process) of the filtration apparatus of FIG. It is a figure explaining the air washing | cleaning process 2 (backwash water piping and treated water piping air washing process) of the filtration apparatus of FIG. It is a figure explaining the backwashing process of the filtration apparatus of FIG. It is a figure explaining the finish washing process of the filtration apparatus of FIG. It is a systematic diagram of the filtration apparatus which shows other embodiment of the washing | cleaning method of the water treatment apparatus water supply piping of this invention. It is a figure explaining the air washing | cleaning process 1 (water supply piping air washing | cleaning process) of the filtration apparatus of FIG. It is a figure explaining the air washing process 2 (process water piping air washing process) of the filtration apparatus of FIG. It is a figure explaining the backwashing process of the filtration apparatus of FIG. It is a figure explaining the finish washing process of the filtration apparatus of FIG. It is a systematic diagram of the water treatment apparatus which shows another embodiment of the washing | cleaning method of the water treatment apparatus water supply piping of this invention. It is a figure explaining the air cleaning process 1 (water supply piping air cleaning process) of the water treatment apparatus of FIG. It is a figure explaining the air washing process 2 (filtered water piping air washing process) of the water treatment apparatus of FIG. It is a figure explaining the backwashing process of the water treatment apparatus of FIG. It is a figure explaining the finishing cleaning process 1 of the water treatment apparatus of FIG. It is a figure explaining the finishing cleaning process 2 of the water treatment apparatus of FIG. It is a figure explaining the air washing process 3 (cation exchange process water piping air washing process) of the water treatment apparatus of FIG.

Detailed description

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In the present invention, the process of performing air cleaning of the water supply piping of the water treatment apparatus is referred to as “air cleaning process 1”, and the process of performing air cleaning of the treated water piping and backwash water piping of the water treatment apparatus is referred to as “air cleaning. This is referred to as “Step 2” or “Air Cleaning Step 3”.

[Embodiment 1]
First, an example of an embodiment of the present invention will be described with reference to FIGS.
1 to 5 are system diagrams of a filtration device showing an embodiment of a water treatment device water supply pipe cleaning method of the present invention. Among these, FIG. 2 shows an air cleaning step 1 (water supply pipe air according to the present invention). FIG. 3 is a diagram showing an air cleaning step 2 (backwash water piping and treated water piping air cleaning step) according to the present invention, and FIG. 4 is a backwashing according to the present invention. FIG. 5 is a diagram illustrating a finishing cleaning process according to the present invention. 2-5, the pipe | tube with which the fluid distribute | circulates is shown with the thick continuous line rather than the pipe | tube with which the fluid does not distribute | circulate. The valve through which the fluid flows is painted black.

1 to 5, 1 is a raw water tank, 2 is a filter, 3 is a treated water tank, P ₁ is a raw water pump, P ₂ is a backwash pump, V ₁ and V ₇ are air inlet valves, and V ₂ is a filtration inlet valve. , _{V 3} is filtered outlet valve, _{V 4} is the backwash outlet valve, _{V 5} is backwashing inlet _{valve, V 6,} V ₈ is washed outlet valve, _{V 9} is a process water tank inlet valve. 11-23 show piping. X ₁ to X ₅ represents a pipe connection part.

The air injection pipe 16 is provided in the discharge portion near the raw water pump P _1, usually, the pipe distance between the connecting portion X ₁ and raw water discharge portion of the pump P ₁ of a water supply pipe 12 and the air injection pipe 16 Is 50 cm or less. Further, the pipe distance piping (backwash drain pipe) 17 and the connecting portions X ₂ and the water supply pipe 12 and the raw water inlet 2A of the filter 2 for discharging the backwash effluent, i.e., the length of the pipe 13 is usually 20 About 200 cm.

The air injection pipe 21 is provided in the discharge portion near the backwash pump P _2, usually connecting portion X ₄ and backwash discharge portion of the pump P ₂ of the air injection pipe 21 and the backwash water pipe 19 And the piping distance is 50 cm or less. Further, the pipe distance between the backwash water pipe 19 and the connecting portion X ₃ of the treated water pipe 15 and the treated water outlet 2B of filter 2, i.e., so that the length of the piping 14 becomes usually about 20~200cm The backwash water pipe 19 is provided in the vicinity of the treated water discharge port 2B of the filter 2 in the treated water pipe. Furthermore, the pipe distance between the pipe (detergent drain pipe) 22 and the treated water inlet 3A of the connecting portions X ₅ and the processing water tank 3 with the treated water pipe 15 for discharging the wash effluent backwash water pipe 19 and the treated water pipe 15, That is, the length of the pipe 23 is usually about 50 to 500 cm.

  In addition, not only the filtration apparatus of FIGS. 1-5, but in any water treatment apparatus, air injection piping is connected to the discharge side of a pump so that air may not enter a pump.

During filtration operation of the raw water is filtered inlet valve V ₂ and filtration outlet valve V ₃ and the process water tank inlet valve V ₉ is opened, the other valves are closed, also operates the raw water pump P _1, stop backwash pump P ₂ Then, the raw water in the raw water tank 1 is introduced into the filter 2 through the pipe 11, the pipe 12 and the pipe 13 and filtered, and the filtered water is introduced into the treated water tank 3 through the pipe 14, the pipe 15 and the pipe 23. To do.

  By continuing such filtration operation, when the pressure loss increases due to dirt in the system or other problems occur, or after the predetermined filtration operation is continued, the following (1) to (7) ) Follow the procedure for cleaning.

(1) Air cleaning process 1 (water supply pipe air cleaning process) (Fig. 2)
While operating the raw water pump P _1, an air inlet valve V ₁ and the backwash outlet valve V ₄ opened, the filtration outlet valve V ₃ and the process water tank inlet valve V ₉ is closed (i.e., the air inlet valve V _1, and filtered an inlet valve V ₂ only backwash outlet valve V ₄ opened, the other valves closed), from the air injection pipe 16, by injecting compressed air into the water supply pipe 12, water supply pipe to the gas-liquid mixed fluid of the raw water and the air 12 The air is washed with air and the washing waste water is discharged from the pipe 17.

In the air cleaning process 1, the raw water is flowing through the normal filtration water supply pipe 12 in operation at the same flow rate, and air blown from the air injection pipe 16 provided in the immediate vicinity of the raw water pump P ₁ raw water Metropolitan By flowing through the water supply pipe 12 as a mixed fluid, turbulent flow is generated in the pipe 12, and contaminants such as microorganisms attached to the inner wall of the pipe 12 are peeled and removed. The gas-liquid mixed flow containing impurities such as the separated microbial mass flows through the filtration inlet valve V ₂ and further flows into the pipe 13, but the backwash outlet valve V _{4 is} opened, and the other Since the valves V ₃ , V ₅ , and V ₆ are closed, they hardly enter the filter 2 and are discharged out of the system through the pipe 17.

By this air cleaning step, of the water supply pipe, upstream of the pipe 12 of the aforementioned connecting portion X ₂ is an air purifier.
Note that the cleaning water for the air-mixed water in the air cleaning step 1 is not limited to raw water, but may be filtered water or water of another system.

(2) Pause process 1
After the air cleaning step 1, the next cleaning step may be performed immediately or a pause step may be interposed. The presence or absence of the pause process does not particularly affect the cleaning effect.
When performing the suspension process, all the valves are closed and the raw water pump P ₁ and the backwash pump P ₂ are stopped.

(3) Air washing process 2 (back washing water pipe and treated water pipe air washing process) (Fig. 3)
In the filtration device of the present embodiment, the treated water pipe and the backwash water pipe through which the treated water circulates are not as large as the feed water pipe, but there is a risk that microorganisms will grow and contaminate may adhere, especially in the backwash water pipe. If the adhering contaminants peel off at the time of backwashing and flow into the filter 2, it causes secondary contamination.

  For this reason, also about the backwash water piping in the case of using the treated water as the backwater and the backwash water, it is preferable to remove the pollutants by air cleaning with the air mixed water, and to discharge out of the system.

Therefore, in the air cleaning step 2, the backwash water pipe 19 and the treated water pipe 15 for cleaning air mixed water, air inlet valves V ₇ and backwash inlet valve V _5, filtered outlet valve V _3, washed outlet the valve V ₈ is opened, the other valves closed, actuating the backwash pump P ₂ (raw water pump P ₁ is stopped), from the air injection pipe 21, by injecting compressed air into the backwash water pipe 19, the pipe the treated water and gas-liquid mixed fluid of air 18 from the process water tank 3 is fed through, and air cleaning by passing the backwash water pipe 19 to the connection part X ₃ a through the process water pipe 15, the detergent drain It is discharged out of the system through the pipe 22.

In the air cleaning step 2, processing the treated water from the water tank 3 is flowing within flow equivalent backwash water pipe 19 and treated water pipe at a rate of 15 in the backwash process will be described later, the most recent backwash pump P ₂ Turbulent flow is generated in the pipes 19 and 15 when the air blown from the air injection pipe 21 provided in the water and the treated water become a mixed fluid and flow in the backwash water pipe 19 and the treated water pipe 15. Then, contaminants such as microorganisms attached to the inner walls of the pipes 19 and 15 are peeled and removed. The gas-liquid mixed flow containing impurities such as the separated microbial mass flows further into a part of the pipe 23, but the treated water tank 3 is closed by closing the treated water tank inlet valve V ₉ provided in the vicinity of the treated water tank inlet. It hardly enters the inside and is discharged out of the system through the pipe 22.

The air washing step 2, of the backwash water pipe, the connection section and the backwash water pipe 19 portion between X ₄ and the connecting portion X _3, among the treated water pipe, the connection portions X ₃ and the connecting portion X portion of the treated water pipe 15 between the ₅ is air cleaned.

In the air cleaning step 2, it is not possible to clean the upstream side of the pipe 18 of the backwash pump P ₂ of the backwash water piping, as much as possible backwash pump P ₂ in the treated water outlet 3B of the treatment water tank 3 By providing them close to each other, the non-cleaning portion of the pipe can be almost eliminated. However, when the length of the pipe 15 is about several meters (1 to 5 m), a cleaning liquid introducing means is provided near the treated water tank 3 of the pipe 15 and a valve is provided on the treated water tank side of the cleaning liquid introducing means. In addition, it may be cleaned once every few days to several weeks.
Further, the pipe 14 between the connecting portions X ₃ and the treated water outlet 2B of filter 2 also, the length of the pipe 14 is at most about 20～200Cm, even the problem during this time the non-cleaning section Absent.
Similarly, the pipe 23 between the treated water inlet 3A of the connecting portions _{X 5} and the processing water tank 3 is also provided in the treated water inlet 3A near the connection portions _{X 5,} a length of tubing 23 500 cm or less, preferably 100 By setting it to ~ 200 cm, the non-cleaning part can be almost eliminated.

Further, the air mixed water from the backwash water pipe 19, there is a risk that flows into the part pipe 14 from the connecting portion X _3, that the filtration inlet valve V ₂ backwashing outlet valve V ₄ is closed Therefore, it hardly flows into the filter 2.

This air washing step 2 is performed prior to the back washing step in order to prevent contaminants in the back washing water pipe from flowing into the filter 2 during the back washing step. If so, it may be before or after the air cleaning step 1.
The air cleaning step 2 can be performed simultaneously with the air cleaning step 1, but is usually performed separately.

In the air washing step 2, the backwash water pipe and the treated water pipe are simultaneously air washed, but the backwash water pipe and the treated water pipe may be washed separately.
For example, the air inlet valve V ₇ and backwash inlet valve V _5, a cleaning outlet valve V ₆ is opened, other valves activates the backwash pump P ₂ is closed (the raw water pump P ₁ is stopped), an air injection pipe the gas-liquid mixed fluid of treated water from the compressed air and the treatment water tank 3 from 21 and air washing by passing the backwash water pipe 19, to discharge the washing water discharge to the outside of the system from the pipe 20 via connection X ₃ Thus, only the backwash water pipe 19 can be washed.

Moreover, about the treated water piping, the air injection piping which inject | pours air into the treated water piping 15 is provided like the air washing process 2 in below-mentioned Embodiment 2, the air inlet valve of this air injection piping, and filtration The inlet valve V ₂ , the filtration outlet valve V ₃ , and the washing outlet valve V ₈ are opened, the other valves are closed, the raw water pump P _{1 is} activated, the backwash pump P _{2 is} stopped, and the raw water is passed through the pipe 12 and the pipe 13. By introducing the gas-liquid mixed fluid of treated water and air from the filter 2 to the pipe 15 and discharging the pipe 22 out of the system, the treated water pipe 15 is cleaned with air. it can.

  However, in this case, it is preferable to perform the cleaning of only the backwashing water pipe before the backwashing process. However, the cleaning of only the treated water pipe is performed after the backwashing process of cleaning the water supply pipe 13. It is preferable to carry out, and further, it may be carried out after the finishing cleaning step described later.

  Note that the cleaning water for the air mixed water in the air cleaning step 2 is not limited to the treated water but may be raw water or water of another system.

  Further, the air cleaning step 2 is not essential and can be omitted as appropriate. That is, the raw water supply pipe needs to be cleaned relatively frequently because the microbial mass (mud ball) grown in the raw water tank 1 flows in, but the filtered water of the raw water circulates. Treated water piping and backwash water piping are less prone to microbial growth than raw water supply piping. For this reason, the air washing process 2 for washing the backwash water pipe and the treated water pipe is performed at a lower washing frequency than the air washing process 1 for washing the raw water supply pipe and the backwashing process described later. It may be omitted depending on the quality of the treated water.

(4) Pause process 2
After the air washing step 2, a back washing step may be performed immediately or a pause step may be interposed. The presence or absence of the pause process does not particularly affect the cleaning effect.
When performing the suspension process, all the valves are closed and the raw water pump P ₁ and the backwash pump P ₂ are stopped.

(5) Backwash process (Figure 4)
As described above, in the air cleaning step 1, the water supply pipe 12 can be peeled and cleaned, but the water supply pipe cannot clean the pipe 13 part downstream of the connection portion X ₂ of the backwash drain pipe 17. Furthermore, there is a risk that the washing water at the time of air washing partially flows into the pipe 13 and the inlet portion in the filter 2 together with microorganisms and the like from which the washing water has been peeled off.
Therefore, in this invention, after performing the above-mentioned air washing process 1, 2, or the air washing process 1, the back washing process is performed and the inside of the filter 2 and the piping 13 part are wash | cleaned.

In the backwashing process, the backwashing inlet valve V ₅ and the backwashing outlet valve V ₄ are opened, the other valves are closed, the backwash pump P _{2 is} activated, the raw water pump P _{1 is} stopped, and the treated water in the treated water tank 3 is Is returned to the filter 2 through the pipe 18, the pipe 19 and the pipe 14, and the backwash waste water is discharged out of the system through the pipe 13 and the pipe 17.
Thereby, the piping 13 part which could not be cleaned in the filter 2 and the air cleaning step 1 can be cleaned, and the contaminants can be discharged out of the system.

(6) Pause process 3
After the backwashing process, the filtration operation may be resumed immediately, or after the finishing washing process described later, the filtering operation may be resumed, and a pause process is interposed between the filtering operation or the finishing washing process. You may let them.
The presence or absence of the pause process does not particularly affect the cleaning effect. When performing the suspension process, all the valves are closed and the raw water pump P ₁ and the backwash pump P ₂ are stopped.

(7) Finish cleaning process (Figure 5)
When performing finish washing, filtration inlet valve V ₂ and washed outlet valve V ₆ opens, other valves were closed, the raw water pump P ₁ operates as backwash pump P ₂ is stopped, the raw water raw water tank 1 pipe 11, the pipe 12 and the pipe 13 are introduced into the filter 2, and the pipe 14, the pipe 20 and the pipe 17 are discharged to the outside of the system.

  1 to 5, the pipe 20 for discharging the washing wastewater is connected to the backwash drainage pipe 17, but this pipe 20 is not connected to the backwash drainage pipe 17, It may be discharged.

  Although this final cleaning is not essential, by performing such final cleaning, contaminants remaining on the outlet side of the filter 2 (contaminants separated from the filter medium in the backwashing step) can be discharged. In addition, as the cleaning water for the final cleaning, filtered water or other system water can be used in addition to the raw water.

After passing through the above series of washing steps, the filtration inlet valve V ₂ and the filtration outlet valve V ₃ are opened again, the other valves are closed, the raw water pump P _{1 is} activated, and the backwash pump P _{2 is} stopped, and the raw water is filtered. Resume.

[Embodiment 2]
Next, another example of the embodiment of the present invention will be described with reference to FIGS.
6 to 10 are system diagrams of a filtration apparatus showing an embodiment of a method for cleaning a water treatment apparatus water supply pipe of the present invention. Among these, FIG. 7 shows an air cleaning step 1 (water supply pipe air according to the present invention). FIG. 8 is a diagram showing an air cleaning step 2 (process water piping air cleaning step) according to the present invention, and FIG. 9 is a diagram showing a back washing step according to the present invention. FIG. 10 is a diagram showing a finish cleaning process according to the present invention. 7 to 10, the pipe through which the fluid flows is shown by a solid line that is thicker than the pipe through which no fluid flows. The valve through which the fluid flows is painted black.

The filtration device shown in FIGS. 6 to 10 has a backwash water pipe 19 and a backwash inlet valve so that backwashing is performed not with treated water but with water with relatively high cleanliness, such as city water and industrial water from outside the system. point V ₅ and backwash pump P ₂ is provided with, different from the filtering device shown in FIGS. 1-5, others have the same construction.
6 to 10, members having the same functions as those shown in FIGS. 1 to 5 are denoted by the same reference numerals.

In this filtration apparatus, the raw water filtration operation, the air washing process 1 (FIG. 7), the back washing process (FIG. 9) and the final washing process (FIG. 10) are performed in the air washing process 1 ( 2), backwashing process (FIG. 4) and finish cleaning process (FIG. 5).
Therefore, description of the air cleaning process 1, the back cleaning process, and the finish cleaning process is omitted, and the air cleaning process 2 for performing air cleaning of the treated water pipe will be described below with reference to FIG.

  In the filtration device of the present embodiment, water having no problem of microbial growth such as industrial water and city water flows through the backwash water pipe, and therefore it is not necessary to perform air washing on the backwash water pipe 19.
  Therefore, in the air washing step 2, the filtration inlet valve V₂, Filtration outlet valve V₃, Air inlet valve V ₇And washing outlet valve V₈Open the other valve and close the raw water pump P₁(Backwash pump P₂The compressed water is injected into the treated water pipe 15 from the air injection pipe 21, and the raw water in the raw water tank 1 is introduced into the filter 2 through the pipe 11, the pipe 12 and the pipe 13. A gas-liquid mixed fluid of treated water and air is flowed to the treated water pipe 15 for air cleaning, and the washing waste water is discharged out of the system through the pipe 22 to remove and remove contaminants in the treated water pipe 15. Drain out.

  In this embodiment, the air washing process 2 does not necessarily need to be performed before the back washing process, and may be after the back washing process. Moreover, you may perform before the air washing | cleaning process 1 and you may carry out after a finishing washing | cleaning process. Further, as in the first embodiment, the air cleaning step 2 can be omitted as appropriate, and the water used for the air cleaning is not limited to raw water but may be water from outside the system such as industrial water.

[Embodiment 3]
Next, still another example of the embodiment of the present invention will be described with reference to FIGS.
FIGS. 11 to 17 are system diagrams of a water treatment apparatus including a filter and a cation exchange tower, showing an embodiment of a method for cleaning a water treatment apparatus water supply pipe of the present invention. Among these, FIG. FIG. 13 is a diagram showing an air cleaning step 1 (feed water piping air cleaning step) according to the invention, FIG. 13 is a diagram showing an air cleaning step 2 (filtered water piping air cleaning step) according to the present invention, and FIG. FIG. 15 is a diagram showing a backwashing process 1 according to the present invention, FIG. 16 is a diagram showing a finishwashing process 2 according to the present invention, FIG. 17 is a diagram showing an air cleaning step 3 (cation exchange treated water piping air cleaning step) according to the present invention.
12-17, the pipe | tube with which the fluid distribute | circulates is shown with the thick continuous line rather than the pipe | tube with which the fluid does not distribute | circulate. The valve through which the fluid flows is painted black.

The water treatment apparatus shown in FIGS. 11 to 17 is provided with a cation exchange tower 4 in the subsequent stage of the filtration apparatus shown in FIGS. 6 to 10, and the filtration apparatus has the same configuration as that shown in FIGS. The members having the same function are denoted by the same reference numerals.
P ₃ is a backwash pump of the cation exchange tower 4, V ₁₁ and V ₁₂ are washing outlet valves, V ₁₀ is a cation exchange inlet valve, V ₁₃ is a backwash inlet valve, V ₁₄ is an air inlet valve, and V ₁₅ is a cation. Exchange outlet valve.
Reference numerals 24 to 31 denote pipes, and X _{6 to} X ₈ denote pipe connection parts.

Piping distance between the inlet 4A of the pipe connecting portion _{X 5} and the cation exchange column 4, i.e. the length of the pipe 23 is usually about 20～200Cm, the treatment water tank 3 and the pipe connecting portion _{X 8} treated water inlet 3A The distance between the pipes, that is, the length of the pipe 27 is usually about 50 to 500 cm.
Moreover, the backwash water pipe 30 and the pipe distance between the connecting part X ₆ and the cation exchange treated water outlet 4B of the cation exchange column 4 of the cation exchange treatment water pipe, i.e., the length of the pipe 24 is usually about 20~200cm Thus, the backwash water pipe 30 is provided in the vicinity of the treated water discharge port 4B of the cation exchange tower 4 in the cation exchange treated water pipe. Furthermore, the pipe distance between the treated water inlet 3A of the connecting portions X ₈ processed water tank 3 and the pipe (detergent drain pipe) 28 for discharging the washing water discharge of the cation exchange treatment water pipe 26 and the treated water pipe 26, i.e., the pipe 27 The length of is usually about 50 to 500 cm.
Further, by providing the connection portion X ₇ between the air injection pipe 31 and the cation exchange treated water pipe in the vicinity of the connection portion X ₆ between the backwash water pipe 30 and the treated water pipe 24, regardless of the length of the pipe 25. Can be air washed.

  During raw water treatment operation, the filtration inlet valve V₂And filtration outlet valve V₃And cation exchange inlet valve V₁₀And cation exchange outlet valve V₁₅Open the other valve, and close the raw water pump P ₁, Backwash pump P₂, P₃The raw water in the raw water tank 1 is introduced into the filter 2 through the pipe 11, the pipe 12 and the pipe 13 and filtered, and the filtered water is further cationd through the pipe 14, the pipe 15 and the pipe 23. The cation exchange treatment water is introduced into the exchange tower 4 and cation exchange treatment water is introduced into the treated water tank 3 through the pipe 24, the pipe 25, the pipe 26 and the pipe 27.

  By continuing such a water treatment operation, when the pressure loss increases due to dirt in the system and other problems occur, or after a predetermined filtration operation is continued, the following (1) to ( Wash according to the procedure of 7).

(1) Air washing process 1 (water supply pipe air washing process) (FIG. 12)
As in the air washing step 1 of the filtration device shown in FIGS. 1 to 10, the air inlet valve V ₁ and the backwash outlet valve V ₄ are opened, the filtration outlet valve V ₃ , and the cation exchange inlet are kept operating the raw water pump P _1. The valve V ₁₀ , the cation exchange outlet valve V ₁₅ and the treated water tank inlet valve V ₉ are closed (that is, only the air inlet valve V ₁ , the filtration inlet valve V ₂ and the backwash outlet valve V ₄ are opened, and the other valves are closed). ), Compressed air is injected into the water supply pipe 12 from the air injection pipe 16, a gas-liquid mixed fluid of raw water and air is passed through the water supply pipe 12 for air cleaning, and cleaning wastewater is discharged from the pipe 17.
In the air cleaning step, the raw water flows through the water supply pipe 12 in a normal filtration operation at the same flow rate, but the air blown from the air injection pipe 16 provided in the immediate vicinity of the raw water pump P ₁ raw water Metropolitan mixture By flowing through the water supply pipe 12 as a fluid, a turbulent flow is generated in the pipe 12, and contaminants such as microorganisms attached to the inner wall of the pipe 12 are peeled and removed. The gas-liquid mixed flow containing impurities such as the separated microbial mass flows through the filtration inlet valve V ₂ and further flows into the pipe 13, but the backwash outlet valve V _{4 is} opened, and the other Since the valves V ₃ , V ₅ , and V ₆ are closed, they hardly enter the filter 2 and are discharged out of the system through the pipe 17.

By this air cleaning step, of the water supply pipe of the filter 2, the upstream side of the pipe 12 of the aforementioned connecting portion X ₂ is an air purifier.
Note that the cleaning water for the air-mixed water in the air cleaning step 1 is not limited to raw water, but may be filtered water or water of another system.

(2) Pause process 1
After the air cleaning step 1, the next step may be performed immediately or a pause step may be interposed. The presence or absence of the pause process does not particularly affect the cleaning effect.
When performing the pause process, all the valves are closed and the raw water pump P ₁ and the backwash pumps P ₂ and P ₃ are stopped.

(3) Air washing process 2 (filtered water piping air washing process) (FIG. 13)
In the air washing step 2, the filtration inlet valve V ₂ , the filtration outlet valve V ₃ , the air inlet valve V ₇ , the cation exchange inlet valve V ₁₀ , and the air washing step 2 of the filtration device shown in FIGS. washed outlet valve V ₈ opens, the other valve is closed, by operating the raw water pump P ₁ (backwash pump P _2, P ₃ is stopped), from the air inlet pipe 21, injecting compressed air into the treated water pipe 15 At the same time, the raw water in the raw water tank 1 is introduced into the filter 2 through the pipe 11, the pipe 12 and the pipe 13, and the mixed water of the treated water and air from the pipe 14 is caused to flow into the treated water pipe 15 for air cleaning. Then, by discharging the cleaning waste water from the pipe 22, the pollutants in the filtered water pipe 15 are peeled off and discharged out of the system.

  This air washing step 2 does not necessarily have to be performed before the back washing step 1 and may be after the back washing step 1. Moreover, you may perform before the air washing | cleaning process 1 and you may carry out after a finishing washing | cleaning process. Further, as in the second embodiment, the air cleaning step 2 can be omitted as appropriate.

(4) Pause process 2
After the air cleaning step 2, the next cleaning step may be performed immediately or a pause step may be interposed. The presence or absence of the pause process does not particularly affect the cleaning effect.
When performing the pause process, all the valves are closed and the raw water pump P ₁ and the backwash pumps P ₂ and P ₃ are stopped.

(5) Backwash process (Figure 14)
In the air cleaning process 1, but allows the stripping and cleaning of the feed water pipe 12 portion of the filter 2, of the feed water pipe, can not be carried out cleaning of the downstream pipe 13 portion of the connecting portion X ₂ of the backwash drain pipe 17 Furthermore, there is a risk that the washing water at the time of air washing partially flows into the pipe 13 and the inlet portion in the filter 2 together with microorganisms and the like from which the washing water has been peeled off.
Similarly, in the air cleaning step 2, perform the stripping and cleaning of the filtration treatment water pipe 15 portion that becomes the feed water pipe cation exchange column 4, but of the pipe, the cleaning of the downstream pipe 23 portion of the connecting portion X ₅ Can't do it.
Therefore, in this invention, after performing the above-mentioned air washing process 1, 2, or the air washing process 1, a back washing process is performed, and the inside of the filter 2, the piping 13,23 part, and the inside of the cation exchange tower 4 are washed. To do.

In the backwash process, the backwash inlet valves V ₅ and V ₁₃ and the backwash outlet valves V ₄ and V ₈ are opened, the other valves are closed, and the backwash pumps P ₂ and P _{3 are} activated and the raw water pump P _{1 is} stopped. The backwash water from outside the system is caused to flow back to the filter 2 via the pipe 19 and the pipe 14, and the backwash waste water is discharged outside the system via the pipe 13 and the pipe 17. Further, the backwash water is caused to flow back to the cation exchange tower 4 through the pipes 30 and 24 and discharged out of the system through the pipes 23 and 22.
As a result, the inside of the filter 2 and the cation exchange tower 4 and the pipes 13 and 23 that could not be washed in the air washing steps 1 and 2 can be washed, and the contaminants can be discharged out of the system.

The backwashing of the filter 2 and the backwashing of the cation exchange column 4 may be performed simultaneously or separately. When performed separately, either may be performed first.
In addition, since the pipe 23 and the cation exchange tower 4 circulate filtered water having less problem of microbial growth than the raw water, they do not need to be cleaned as frequently as the pipe 13 and the filter 2. The back washing of the cation exchange tower 4 and the pipe 23 serving as the water supply pipe may be omitted as appropriate, or may be performed less frequently than the back washing of the pipe 13 and the filter 2.

(6) Pause process 3
After the back washing step, the filtration operation may be resumed immediately, and after performing the finishing washing steps 1 and 2 and the air washing step 3 described later, the water treatment operation may be resumed. A pause process may be interposed between the cleaning process and the cleaning process.
The presence or absence of the pause process does not particularly affect the cleaning effect. When performing the pause process, all the valves are closed and the raw water pump P ₁ and the backwash pumps P ₂ and P ₃ are stopped.

(7) Finishing cleaning steps 1 and 2 (Figs. 15 and 16)
When performing finish washing of the filter 2, as in the case of the filtration apparatus of FIGS. 1-10, the filtered inlet valve V ₂ and washed outlet valve V ₆ is opened, other valves were closed, the raw water pump P ₁ operates As the backwash pumps P ₂ and P _{3 are} stopped, the raw water in the raw water tank 1 is introduced into the filter 2 through the pipe 11, the pipe 12 and the pipe 13, and is discharged out of the system through the pipe 14, the pipe 20 and the pipe 17. (FIG. 15).

  In addition, when the cation exchange tower 4 is subjected to final cleaning, the filtration inlet valve V₂And filtration outlet valve V ₃And cation exchange inlet valve V₁₀And washing outlet valve V₁₂Open the other valve and close the raw water pump P₁Operation, backwash pump P₂, P₃As a stop, the raw water in the raw water tank 1 is introduced into the filter 2 through the piping 11, the piping 12 and the piping 13, and further introduced into the cation exchange tower 4 through the piping 14, the piping 15 and the piping 23, and then the piping. 24, discharged through the piping 29 and the piping 22 to the outside of the system.

After a series of the above washing step, the filtration inlet valve V ₂ and filtration outlet valve V ₃ and the cation exchange inlet valves V ₁₀ and cation exchange outlet valve V ₁₅ opens again, the other valves closed, the raw water pump P ₁ operates As the backwash pumps P ₂ and P _{3 are} stopped, the water treatment operation of the raw water is resumed.

  In addition, in an ion exchange tower packed with a cation exchange resin such as a cation exchange tower, trace metal ions necessary for the growth of microorganisms are removed by the cation exchange resin in the tower. Microbial growth is not a problem. Therefore, the pipe through which the ion exchange treated water of the ion exchange tower circulates does not need to be washed with air in particular, but it cannot be said that there is no possibility of microbial growth. Air cleaning may also be performed on the pipes after the ion exchange tower at a cleaning frequency much lower than that in the cleaning step.

Water treatment apparatus shown in FIG. 11 to 17, which has provided the air injection pipe 31 therefor when the air wash is a cation exchange treated water pipe, as shown in FIG. 17, filtered inlet valve V _2, filtered outlet valve _{V 3,} the cation exchange inlet valves _{V 10,} cation exchange outlet valve _{V 15,} the air inlet valve _{V 1 4} and the cleaning outlet valve _{V 11} open, other valves were closed, while the raw water pump _{P 1} is actuated (reverse The washing pumps P ₂ and P ₃ are stopped), the raw water in the raw water tank 1 is introduced into the filter 2 through the pipe 11, the pipe 12, and the pipe 13, and the filtered water of the filter 2 is supplied to the pipe 14, the pipe 15, The cation exchange treated water pipe 26 is introduced into the cation exchange tower 4 through the pipe 23 and the cation exchange treated water from the pipes 24 and 25 is passed through the pipe 26 as air mixed water together with the air from the air injection pipe 31. Air wash, The purification waste water is discharged from the pipe 28 to the outside of the system.

  The air washing of the cation exchange treated water pipe 26 is not limited to the treated water obtained by subjecting the raw water from the raw water tank 1 to the filtration treatment and the cation exchange treatment, and air using water such as industrial water from outside the system. You may wash | clean and air wash with the water in the treated water tank 3.

  The air injection pipe 31 may be connected to the backwash water pipe 30 to wash the cation exchange treated water pipe with air mixed water using water from outside the system.

[Air cleaning conditions]
In the above-described air cleaning step 1 for cleaning the water supply piping of a water treatment device such as a filter or a cation exchange tower, if the amount of injected air is small, the effect of removing microorganisms is weak, and in order to obtain a sufficient cleaning effect, It is not preferable because the cleaning process needs to be lengthened, the operation efficiency is lowered, and the amount of drainage is increased. However, if the air injection amount is increased, the economic efficiency is impaired such as an increase in the size of a device such as a compressor for injecting compressed air and an increase in power consumption. Therefore, it is desirable to adjust the air injection amount and the cleaning time of the air cleaning process so that a high cleaning effect can be obtained while suppressing the cleaning cost.

In the air cleaning step 1 of the present invention, the amount of air injected is 4 to 10 L / min, preferably 4 to 5 L / min per 1 cm ^{2 of the} cross-sectional area of the water supply pipe to be cleaned, and the cleaning time of the air cleaning step is The reference time T (minute) calculated by the following formula (I) is preferably three times or more.
T = {S × L × 0.001 / W} (I)
(Where S is the cross-sectional area of the water supply pipe (cm ² ), L is the length of the water supply pipe through which the air-mixed water flows (length of the water supply pipe 12 in FIG. 1) (cm), W is the amount of water flow during cleaning ( L / min).)

  If the air injection amount is less than the above range, a sufficient cleaning effect cannot be obtained, and if it is large, it is uneconomical.

  Further, if the cleaning time is less than three times the reference time T, a sufficient cleaning effect cannot be obtained. However, since it is disadvantageous even if the cleaning time is excessively long, the cleaning time is preferably set to be not more than 5 times the reference time T.

  In addition, the water flow rate at the time of air washing is normally set to about 0.5 to 2 m / s, and the amount of water flow at the time of air washing varies depending on the cross-sectional area of the pipe.

  Regarding the air cleaning conditions in the air cleaning processes 2 and 3 for performing air cleaning of the backwash water pipe and the treated water pipe, these pipes are less prone to microbial growth than the water supply pipes. May be performed under the same cleaning conditions as in the air cleaning step 1.

For example, in the air cleaning steps 2 and 3 in the present invention, the air injection amount is 4 to 10 L / min per 1 cm ^{2 of the} cross-sectional area of the backwash water pipe or the treated water pipe to be cleaned. The time is preferably at least three times the reference time T ′ (minute) calculated by the following formula (I ′).
T ′ = {S ′ × L ′ × 0.001 / W ′} (I ′)
(However, S ′ is the cross-sectional area (cm ² ) of the backwash water pipe or treated water pipe, and L ′ is the length of the backwash water pipe or treated water pipe through which the air-mixed water flows (the pipes 19 and 15 in FIG. 1). (Length) (cm), W ′ is the amount of water flow (L ′ / min) during cleaning.)

  If the air injection amount is less than the above range, a sufficient cleaning effect cannot be obtained, and if it is large, it is uneconomical.

  Further, if the cleaning time is less than 3 times the reference time T ′, a sufficient cleaning effect cannot be obtained. However, since it is disadvantageous that the cleaning time is excessively long, it is preferable that the cleaning time is not more than 5 times the reference time T ′.

  In addition, the water flow rate at the time of air washing is normally set to about 0.5 to 2 m / s, and the amount of water flow at the time of air washing varies depending on the cross-sectional area of the pipe.

[Time for each cleaning step]
There are no particular restrictions on the specific times of the air washing steps 1 to 3, the back washing step, and the finishing washing step and the pause step performed as necessary according to the present invention. It is preferable that

Air washing process 1: 1 to 10 minutes Air washing process 2, 3: 1 to 10 minutes Back washing process: 5 to 15 minutes Pause process: 5 minutes or less Finish washing process: 5 to 10 minutes

[Raw water to be treated by water treatment equipment]
Such a water treatment apparatus water supply pipe cleaning method of the present invention is a water treatment apparatus for treating wastewater containing a large amount of organic matter, in particular, phosphorus and / or nitrogen serving as nutrient salts of microorganisms, in which microorganisms are likely to grow. Examples of the water quality of the organic matter-containing wastewater that is effective for cleaning the water supply pipe and are applied include the following.

<Organic-containing wastewater quality>
Organic substance concentration: 0.1 to 100 mg / L (as TOC)
SS concentration: 0 to 10 mg / L
Phosphorus concentration: 0.1 to 1000 mg / L (as P)
Nitrogen concentration: 0.1-20 mg / L (as N)

[Water treatment equipment]
There is no particular limitation on the configuration or the like of the water treatment device to be cleaned in the present invention, and the water treatment device main body filled with water treatment material and backwashed periodically or as necessary, and vice versa. Any water treatment apparatus provided with a washing mechanism can be effectively applied by connecting an air injection pipe to the water supply pipe, or by further connecting an air injection pipe to the treated water pipe.

  Moreover, there is no restriction | limiting in particular also in the water flow direction to a water treatment apparatus main body, Even if it is an upward flow system, a downward flow system may be sufficient.

  As the water treatment material, various filter media such as sand, anthracite, inert resin, waste ion exchange resin and the like can be used, and ion exchange resin and activated carbon may be used.

Examples of the water treatment apparatus main body of the water treatment apparatus to which the water treatment apparatus water supply pipe cleaning method of the present invention is applied include the following, but are not limited thereto.
(1) Filter with a filter medium filled as a water treatment material
(2) Ion exchange tower filled with ion exchange resin as water treatment material
(3) Water softener filled with ion exchange resin as water treatment material
(4) Activated carbon tower filled with activated carbon as water treatment material

  Hereinafter, the present invention will be described in more detail with reference to experimental examples and examples.

[Experimental Example 1]
In order to investigate the relationship between the amount of injected air, the amount of water flow, the time of air cleaning, and the length of the water supply pipe, the organic wastewater was passed through a 15A clear polyvinyl chloride pipe (cross-sectional area 1.8 cm ² ). An experiment was conducted in which air was injected once every two days for air cleaning. In addition, the water flow rate of the organic substance-containing waste water was made constant at 8.3 L / min, and the air injection amount and the injection time (time of the air cleaning step) were variously changed.

  After conducting this experiment for 2 months, the distance from the air injection point is 5 m, 15 m, and 30 m, and visually observe the state of microorganisms on the inner wall of the pipe. When the effect was acquired, it was evaluated as “◯”, the adhesion of microorganisms was observed, and when the cleaning effect was not sufficient, it was evaluated as “x”, and the results are shown in Tables 1 to 3.

From Tables 1 to 3, there are lower limits to the air injection amount and the air cleaning time for obtaining a sufficient air cleaning effect. The cleaning time is T = {pipe cross-sectional area (1.8 cm ² ) × pipe length (500 cm (1500 cm or 3000 cm) × 0.001 ÷ water flow rate (8.3 L / min)} (min) It is understood that it is preferably 3 times or more.

[Example 1]
In the filtration device (filter medium: anthracite) of FIG. 1 that is filtering raw water of the following water quality, the pump and valve are opened and closed according to the time chart shown in Table 4 below, and the air washing step 1, the pause step 1, A series of washings of the air washing step 2, the pause step 2, the back washing step, the pause step 3, and the finish washing step was performed once every two days of the raw water filtration operation.

<Filtration raw water quality>
Organic substance concentration: 5 mg / L (as TOC)
SS concentration: 1 mg / L
Phosphorus concentration: 500 mg / L (as P)
Nitrogen concentration: 5 mg / L (as N)

The cross-sectional area of the water supply pipe is 1.8 cm ² , the length of the water supply pipe through which the air-mixed water is passed (the length of the pipe 12) is 500 cm, and the length of the water supply pipe of the non-air cleaning unit (the pipe 13). The length) was 20 cm, the water flow rate during filtration was 2 L / min, the air injection rate was 4 L / min, and the water flow rate during backwashing was 2 L / min (reference time T was 0.45 minutes).

The cross-sectional area of the backwash pipe is 1.8 cm ² , the cross-sectional area of the treated water pipe is 1.8 cm ² , and the length of the backwash water supply pipe and the treated water pipe through which the air-mixed water is passed (pipe 19 and the pipe 15) is 500 cm, the length of the treated water pipe 14 of the non-air washing unit is 10 cm, the length of the pipe 23 is 5 cm, the treated water flow rate in the air washing step 2 is 2 L / min, air The injection amount was 4 L / min (reference time T ′ was 0.45 minutes).

  As a result, even after the operation was continued for 6 months, the microorganisms did not adhere to or grow on the water supply pipe, and the operation could be continued stably.

Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.
In addition, this application is based on the Japanese patent application (Japanese Patent Application No. 2008-073918) for which it applied on March 21, 2008, The whole is used by reference.

Claims (11)

A water treatment device main body filled with water treatment material and backwashed periodically or as necessary, a water supply pipe for supplying raw water to the water treatment device main body, and treated water from the water treatment device main body A water treatment apparatus having a treated water pipe to be taken out, a backwash water pipe for supplying backwash water to the main body of the water treatment apparatus, and a backwash drainage pipe connected to the water supply pipe for discharging backwash wastewater to the outside of the system In the method of cleaning the water supply pipe of
An air washing step of supplying air-mixed water upstream of the connection between the backwash drainage pipe and the water supply pipe, and discharging the air-mixed water from the backwash drainage pipe through the connection;
Thereafter, backwash water is supplied to the main body of the water treatment device, and the backwater drainage from the main body of the water treatment device is washed out through the backwashing drainage pipe through the connecting portion and the water supply pipe is washed. A method for cleaning a water supply pipe of a water treatment device. In Claim 1, the amount of air injected into the water supply pipe in the air cleaning step is 4 to 10 L / min per 1 cm ² of the cross-sectional area of the water supply pipe, and the cleaning time of the air cleaning process is expressed by the following formula (I The water treatment apparatus water supply pipe cleaning method is characterized in that it is at least three times the reference time T (minutes) calculated in (1).
T = {S × L × 0.001 / W} (I)
(However, S is the cross-sectional area (cm ² ) of the water supply pipe, L is the length (cm) of the water supply pipe through which the air-mixed water flows, and W is the water flow rate (L / min) during cleaning.)   3. The finishing cleaning step according to claim 1 or 2, wherein after the back washing step, raw water is supplied to the main body of the water treatment device via the water supply pipe, and discharged water from the main body of the water treatment device is discharged out of the system. A method for cleaning a water supply pipe of a water treatment apparatus.   The water treatment apparatus water supply pipe according to any one of claims 1 to 3, further comprising a process water pipe air cleaning step of supplying an air mixed water to the process water pipe and discharging it to the outside of the system. Cleaning method.   6. The water treatment device according to claim 1, wherein the water treatment device stores the treated water from the treated water pipe, and the water treatment device uses the treated water in the treated water bath as the backwash water. A backwash water pipe for supplying to the main body, and performing a backwash water pipe air washing process for supplying air mixed water to the backwash water pipe and discharging it outside the system prior to the backwash process. A water treatment device water supply pipe cleaning method.   6. The backwash water pipe according to claim 5, wherein the backwash water pipe is connected to the treated water pipe in the vicinity of a treated water discharge port of the water treatment apparatus main body, and prior to the backwashing process, the mixed water is supplied with the backwash water. A backwash water pipe and a treated water pipe air washing process for discharging water from the pipe through the connecting portion of the treated water pipe and the backwash water pipe to the treated water pipe in the direction of the treated water flow and then discharging to the outside of the system is performed. A method for cleaning a water supply pipe of a water treatment apparatus.   7. The water treatment apparatus water supply pipe cleaning method according to claim 1, wherein the water treatment apparatus main body is a filter in which a filter medium is filled as the water treatment material.   The water treatment device water supply pipe according to any one of claims 1 to 6, wherein the water treatment device main body is an ion exchange tower filled with an ion exchange resin as the water treatment material. Method.   7. The water treatment apparatus water supply pipe cleaning method according to claim 1, wherein the water treatment apparatus main body is a water softener filled with an ion exchange resin as the water treatment material. .   7. The water treatment device water supply pipe cleaning method according to any one of claims 1 to 6, wherein the water treatment device main body is an activated carbon tower filled with activated carbon as the water treatment material.   11. The water treatment apparatus water supply pipe cleaning method according to any one of claims 1 to 10, wherein the raw water is organic substance-containing water.

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