JPH1028817A - Method for washing floating filter material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To well and uniformly wash a floating filter material. SOLUTION: In a method for washing a floating filter material 2 formed from a synthetic resin with a particle size of about 1mm and a thickness of about 10-15cm charged in a filter apparatus main body in a state suspended in a liquid with a washing fluid jetted from the washing means 4 having two pairs of jet orifices 4a jetting washing water laterally and a jet orifice 4b jetting washing water upwardly arranged in the filter apparatus main body 1, a fluid is introduced into the upper part of the filter apparatus main body 1 to wash the floating filter material while moving the position thereof up and down.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for cleaning a floating filter material filled for performing water treatment in a filtration device.

[0002]

2. Description of the Related Art In recent years, in the treatment of wastewater or the like, in order to remove suspended substances such as sludge in raw water to be treated, a main body of the treatment apparatus is made of a foaming synthetic resin or the like which is lighter than water. A filtering device using a floating filter medium is used.

[0003] In this filtration device, raw water is introduced into a filter device main body from a lower raw water inlet, and the raw water is brought into contact with an upper floating filter medium to adsorb suspended substances and the like to the filter medium so as to remove treated water. The treated water is discharged from a treated water discharge port. Near the treated water discharge port, an outflow prevention member made of a wire mesh or the like is provided to prevent the filter medium from flowing out together with the treated water.

[0004]

The use of such a floating filter medium requires periodic cleaning because suspended substances and the like are attached to the filter medium and the filtration performance deteriorates. In such a case, the washing is performed by a so-called reverse washing method of washing the filter medium by flowing washing water in a direction opposite to the flow of the raw water.

[0005] However, since the floating filter medium usually forms a floating filter layer having a certain thickness or more (for example, 15 to 20 cm or more), if a fluid is jetted from one direction to the filter medium,
Although the vicinity of one side of the floating filter medium layer was washed, it was difficult to wash all layers uniformly and reliably.

Further, as described above, an outflow preventer such as a wire mesh is attached to the filtering device body so that the filter medium does not flow out, and there is a possibility that dirt adheres to the wire mesh to contaminate the treated water. Since the wire mesh may be clogged with dirt and the pressure loss may increase, and the flow of the treated water may deteriorate, the wire mesh also needs to be periodically cleaned. However, it is usually necessary to remove the filter from the main body of the filtration device for cleaning, which is troublesome and inefficient in work efficiency, and it is difficult to perform frequent cleaning because of such complicated work.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to provide a method for cleaning a floating filter medium, which can clean the floating filter medium satisfactorily and uniformly.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has been made as a method for cleaning a floating filter medium. In the method for cleaning a floating filter medium 2 filled in a state with a cleaning fluid ejected from a cleaning means 4 provided in the filter apparatus main body 1, a floating filter medium 2 is filled with a fluid at an upper part of the filter apparatus main body 1. The purpose is to wash the floating filter medium 2 while introducing and moving the position of the floating filter medium 2 up and down by the fluid.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a filtration device main body, and a raw water introduction passage 5 for introducing raw water such as drainage to be filtered into the device main body 1 is connected to a lower portion of the filtration device main body 1, and an upper portion thereof is connected to an upper portion thereof. A treated water discharge port 6 for discharging treated water treated in the apparatus main body 1 to the outside is provided.

Reference numeral 2 denotes a particle diameter 1 floating on the water surface in the apparatus main body 1.
It is a floating filter medium formed of a synthetic resin having a thickness of about mm and having a thickness of about 10 to 15 cm or more. The floating filter medium 2 has a property of adsorbing suspended substances such as algae and dirt in the contacted raw water and filtering the raw water. Further, a microbe or a certain kind of microbial body may be carried on the surface of such a granular filter medium.

Reference numeral 3 denotes a wire mesh provided at an upper portion of the apparatus main body 1 as an outflow preventing body.
In order to prevent the floating filter medium 2 from flowing out together with the treated water, the filter medium 2 is attached to the upper portion of the filtration device main body 1 through a packing 9 provided at a peripheral portion below the treated water drainage port 6 in a tight contact state. .

Reference numeral 4 denotes a washing nozzle as washing means for ejecting washing water in a washing step. The washing nozzle 4 has two pairs of ejection ports 4a for ejecting washing water to the side, and upwards. The spout 4b for spouting the washing water is formed so as to be located substantially at the center of the filter device main body 1. As the washing water, spraying a liquid mixed with ordinary water or a detergent,
Alternatively, air and liquid may be injected simultaneously.

V1 is a switching valve provided in the treated water discharge passage 6. The switching valve V1 opens the treated water discharge passage 6 to discharge treated water from the filtration device main body 1 during a normal filtration step. On the other hand, in the washing step, the switching valve V1 closes the treated water discharge passage 6.

Reference numeral 7 denotes an air injection passage connected to the treated water discharge passage 6 on the upstream side of the switching valve V1. The air injection passage 7 is provided with a pump P1. When the valve V1 is closed, air containing ozone can be sent to the apparatus main body 1 side.

The ozone mixed into the air is generated by an ozone generator (not shown) connected to the air injection path 7 and mixed with the air in the air injection path 7.

V2 is a switching valve connected below the raw water introduction passage 5, and normally closes the valve V2 during the filtration step, so that the raw water is filtered by the pump P2 connected to the raw water introduction passage 5. During the washing step, the valve V2 is opened so that the water at the bottom of the filtration device main body 1 is discharged from the drain 10 provided below the raw water introduction passage 5.

V3 is a valve provided in the washing water introduction passage 12 connected to the washing nozzle 4. The valve V3 is closed during a normal filtration step, and is opened during the washing step to remove washing water. To supply.

A description will be given of the case of using the filtering apparatus having the above-described configuration. First, in a normal filtering step, the switching valve V2 and the valve V3 are closed and the pump P2 is closed.
Is operated to introduce the raw water from the raw water introduction passage 5 into the lower portion of the filter device main body 1.

The raw water comes into contact with the floating filter medium 2 floating above the filter device body 1 in an upward flow from the bottom upward, and suspended substances such as sludge and algae in the raw water are mixed with the floating filter medium 2. The raw water is adsorbed and purified as treated water.

Then, the treated water is discharged from the treated water discharge passage 6 at the upper part of the filtration device main body 1 to the outside of the filtration device main body 1,
Since the switching valve V1 of the treated water discharge passage 6 is open,
It is discharged as it is as treated water.

At this time, since the floating filter medium 2 is prevented from being discharged from the treated water discharge path 6 together with the treated water by the wire mesh 3, the floating filter medium 2 is not lost.

At the time of this filtration step, the filtration device body 1
Is located at the top of the filter body 1 and therefore
The upper surface of the floating filter medium 2 is in contact with the outflow prevention wire mesh 3.

Next, a description will be given of a cleaning step of cleaning the floating filter medium 2 after performing such a filtering step for a predetermined time.

First, the switching valve V1 is closed, and at the same time, the switching valve V2 is opened to open the drain 10. Then, the supply of the raw water is stopped by stopping the pump P2. further,
The valve 3 of the washing water introduction passage 12 is opened, and washing water is injected from the injection ports 4a and 4b as shown in FIG.

Further, since air containing ozone sent from the treated water discharge passage 6 by the pump P1 is introduced into the upper part of the filtering device main body 1, the water level of the filtering device main body 1 is lowered by the pressure of the air. While the water level is falling, the washing water is jetted from the jets 4a and 4b.

When the water level drops to a predetermined minimum water level A, the jetting port 4b of the washing nozzle 4 projects from the surface of the water, and the washing water is jetted upward.
(See FIG. 2A). Therefore, the floating filter medium 2
Can be cleaned by the cleaning liquid sprayed to the side, and at the same time, the wire net 3 can be cleaned by the cleaning water from the spray port 4b. Furthermore, since the cleaning water is sprayed from below on the wire net 3 and the air is also sprayed from above, the dirt and the like adhered more strongly can be washed.

Further, since the air introduced into the filter device body 1 contains ozone, there is also an effect of sterilizing the wire net 3, the floating filter medium 2 or the filter device body 1 with ozone as the water level decreases.

As described above, by washing the wire mesh 3 and the floating filter medium 2, suspended substances such as sludge separated from the floating filter medium 2 and the wire mesh 3 are discharged from the open drain 10.

The minimum water level A can be detected by a preset water level detection means such as a timer or a sensor. , So that the wire net 3 can be washed by the force of the washing liquid.
It is preferable that the water level is set such that 4b projects from the water surface and the floating filter medium 2 is not discharged from the raw water inlet 5.

As means for maintaining the water level A, the pump P1 is stopped to stop the supply of air, and at the same time, the switching valve V
When the washing water is continuously jetted in this state while closing the filter 1 and leaving air at the upper part of the filter device main body 1, a constant water level A can be maintained by the pressure of the remaining air.

After the floating filter medium 2 and the wire net 3 have been washed for a certain period of time in such a state of the minimum water level A, the switching valve V1 is opened and the air remaining on the upper part of the filtration device main body 1 is removed. It is discharged from the treated water discharge filter 6. Also, the switching valve V2
Is closed, and drainage from the drain 10 is stopped.

Then, the pressure in the upper portion of the filter device 1 is reduced because the air in the upper portion of the filter device 1 is released, and the water level in the filter device body 1 is increased because the washing water is jetted without being discharged. . When the water level reaches a certain water level A '(see FIG. 2 (b)), the switching valve V1 is closed again, and the switching valve V2 of the drain 10 is opened to maintain the water level A'. The floating filter medium 2 is washed for a certain period of time.

Further, in the same manner, the water level is raised to the vicinity of the wire mesh 3 by raising the water level (see FIG. 2 (c)), and while maintaining the water level at this position, the floating filter medium is taken for a certain period of time. Wash 2

By repeating such a change in the water level and washing the floating filter medium 2, a thick floating filter medium 2 is obtained.
Can be uniformly washed at any position of the layer.

Further, by lowering the water level and cleaning, the wire net 3 provided on the upper portion of the apparatus main body 1 can be simultaneously cleaned with the cleaning water injected from the cleaning nozzle 4. In this case, it is not always necessary that the ejection port 4b for ejecting the water above the washing nozzle 4 protrudes from the water surface.
It is only necessary that the wire net 3 can be washed with the force of the washing water injected from the injection port 4b.

In the above-mentioned embodiment, the floating filter medium 2 is washed at three places by setting three water levels A, A ', and A''. However, the floating filter medium is washed at two positions. Alternatively, three or more locations may be used. In addition, the up-and-down movement may be repeated many times to wash, and in short, the floating filter medium 2 that is easily washed by the washing water injected from the washing nozzle 4.
It is sufficient that the floating filter medium 2 can be moved up and down so that the height of the floating filter medium 2 is changed.

Further, in the above-described embodiment, the wire net 3 is also washed when the floating filter medium 2 is washed. However, it is not a condition that such a wire mesh is washed when the floating filter medium is washed. In addition, as means for preventing the floating filter medium 2 from flowing out, means other than wire mesh,
For example, a plate-like body having small holes may be used, and the provision of such an outflow prevention body is not a condition.

In the above embodiment, air containing ozone was introduced to lower the water level, but other air or gas may be used as a fluid to be introduced to lower the water level. May be.

Further, in the above-described embodiment, the treated water discharge path 6 provided with the switching valve V1 is used as a path for introducing air. However, the treated water discharge path 6 separates fluid such as air into the apparatus main body 1. May be provided as long as it can switch the discharge of the treated water and the introduction of a fluid such as air.

Also, a switching valve V2 is provided in the raw water introduction passage 5 so that the raw water is introduced during the filtration step, and the drain 10 is formed so as to be freely switchable as the drain 10 in order to lower the water level in the apparatus body during the washing step. The channel and drain for drainage may be provided separately.

However, as in the above embodiment, the switching valve V1
, V2 are provided, and the treated water discharge passage is formed as a passage for introducing air, and the raw water introduction passage is formed as a drain passage so as to be freely switchable. It is economical because it requires less installation space.

In addition, the specific configuration of the apparatus main body 1, the floating filter medium 2, and the like can be freely changed in design within the range intended by the present invention.

[0044]

As described above, according to the method for cleaning a floating filter medium of the present invention, a layer of a floating filter medium having a predetermined thickness can be uniformly and reliably cleaned at any position. Therefore, the filtering ability of the floating filter medium can be reliably maintained for a long time, and the filter medium can be used semipermanently.

Further, since the outflow preventing body of the filter medium can be washed simultaneously with the washing of the floating filter medium, maintenance of the apparatus can be performed more easily, and the treated water is contaminated by sludge or the like attached to the outflow preventing body. It is possible to reliably prevent the flow of water from being deteriorated.

Further, since the floating filter medium is moved up and down by the air mixed with ozone, the filter medium and the inside of the filter device can be sterilized by the ozone in the air, and a more reliable cleaning effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing an example of an embodiment of a filtration device of the present invention.

2A is a schematic front view showing a washing state at the lowest water level of the floating filter medium, FIG. 2B is a schematic front view showing a washing state at an intermediate water level, and FIG. Front view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Filtration device main body 2 ... Floating filter medium 3 ... Wire mesh (outflow prevention body) 4 ... Washing nozzle (washing means)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B01D 29/08 530C 540A

Claims (3)

[Claims] 1. A floating filter medium (2) filled in a state of being suspended in a liquid in a filter device main body (1) is ejected from a washing means (4) installed in the filter device main body (1). In the method for cleaning a floating filter medium to be washed with a cleaning fluid, a fluid is introduced into the upper part of the filter device body (1), and the position of the floating filter medium (2) is moved up and down by the fluid so as to move the floating filter medium (2).
A method for cleaning a floating filter medium, comprising washing a filter medium. 2. An outflow preventer (3) for preventing the outflow of the floating filter medium (2) is provided on the treated water outlet side of the filter device body (1), and the position of the floating filter medium (2) is lowered. 2. The method for cleaning a floating filter medium according to claim 1, wherein the outflow prevention body (3) is cleaned by the cleaning means (4) when the cleaning is performed. 3. The method for cleaning a floating filter medium according to claim 1, wherein the fluid introduced into the upper portion of the filter device main body (1) is air containing ozone.