JPH10484A - Method for washing floating filter medium and filtering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a washing method for a floating filter medium by which washing effect is good and the floating filter medium is economically washed and to provide a filter. SOLUTION: In the washing method for the floating filter medium, a preventive body against an outflow of the filter medium is provided to prevent the floating filter medium 2 from being flowed out to the upside thereof. Further, a washing means is provided on the underside of the floating filter medium 2 in not passing through the preventive body 3 against an outflow of the filter medium. In this case, the floating filter medium 2 is filled on the underside of the preventive body 3 against the outflow of the filter medium. Drainage is performed from the lower part of the body 1 of the device so that the water level is positioned in the nearly low part of the preventive body 3 against the outflow. Furthermore, fluid is spouted from the above-mentioned washing means to wash the floating filter medium 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

That is, a floating filter medium is filled in a state of being suspended in raw water in a filter apparatus main body, and an upper filter medium made of a wire mesh or the like for preventing the floating filter medium from flowing out from an upper portion of the filter apparatus main body together with treated water. A lower filter medium outflow prevention body similar to the upper filter medium outflow prevention body is provided below the floating filter medium so that the floating filter medium does not flow out from a drain hole provided in a lower portion of the body and the apparatus main body.

When such a floating filtration device is used, during a normal filtration step, raw water such as drainage is introduced into the filtration device main body through, for example, a raw water inlet provided at a lower portion of the device main body. The suspended material in the raw water is adsorbed on the floating filter medium by contacting the filter medium in an upward flow to treat the raw water, and the treated water is discharged from an upper drainage channel.

[0005]

As such a floating filter medium is used, suspended substances and the like adhere to the surface of the filter medium as the filter medium is used, and the filtration performance deteriorates.
When cleaning the floating filter medium, the water is lowered so that the surface of the floating filter medium is located between the upper and lower filter medium outflow preventers, and air or water is supplied from the cleaning means provided at the lower part of the apparatus main body. Such a method is performed that the filter medium is washed while ejecting a fluid such as the above, and then the suspended matter separated from the filter medium by the washing is discharged out of the apparatus main body from a discharge path provided at the bottom of the apparatus main body. Was.

[0006] According to such a method, when the water level is above the upper filter medium outflow prevention body at the time of washing the floating filter medium,
The floating filter medium is pressed against the lower surface side of the upper filter medium outflow preventive body by the cleaning fluid from below, and is not sufficiently flown, so that the cleaning efficiency is reduced.

Therefore, when the floating filter medium is washed, the water level is lowered to such an extent that a predetermined distance is formed between the upper filter medium outflow prevention member and the surface of the floating filter medium. However, when the water level is greatly lowered, a large amount of drainage is generated. And a separate storage tank for the wastewater had to be provided. For this reason, there has been a problem that the apparatus becomes large, the manufacturing cost or the space cost increases, and it is uneconomical.

When the water is drained from the discharge channel at the bottom of the apparatus body during washing to lower the water level, the filter medium is prevented from flowing out together with the drainage from the discharge channel at the bottom as described above. It was necessary to provide a lower filter medium outflow prevention member also on the side.

However, a cleaning device for cleaning the floating filter medium is provided at the bottom of the main body of the apparatus. When the lower filter medium outflow prevention member is provided as described above, air or cleaning water from the cleaning apparatus is provided. Since the fluid such as flows through the lower filter medium outflow preventer, the energy loss is increased, the stirring and mixing effect is reduced, and the effect of washing the floating filter medium is reduced.

[0010] Further, when the contaminated material is contaminated due to the adhesion of suspended substances to the vicinity of the cleaning device or the drain hole, the portion must be cleaned. In this case, the cleaning device and the drain hole are obstructed during cleaning, and must be removed once, which makes the operation complicated. A similar problem has arisen when repairing or replacing the cleaning device.

Further, there is a problem that the suspended solids separated from the floating filter medium are prevented from settling at the bottom of the apparatus main body by the lower filter medium outflow preventer, and cannot be discharged well from the discharge hole at the bottom of the apparatus main body. Had occurred.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a method and apparatus for cleaning a floating filter medium which has a good cleaning effect and can economically wash the floating filter medium. The task is to

[0013]

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems.
The filter device main body 1 has a filter medium outflow preventive body 3 for preventing outflow to the upper side of the filter medium, and a washing means 4 is provided below the floating filter medium 2 without the filter medium outflow preventive body 3. In the method for cleaning the floating filter medium suspended in the water, the floating filter medium 2 is filled below the filter medium outflow prevention body, and the water level is slightly below the filter medium outflow prevention body 3 from the lower portion of the apparatus main body 1. The purpose is to wash the floating filter medium by draining the water and ejecting a fluid from the washing means 4.

(Action) That is, the cleaning method of the present invention comprises:
A filter device main body 1 having a filter medium outflow preventive body for preventing the floating filter medium 2 from flowing out to the upper side, and a washing means provided below the floating filter medium 2 without the filter medium outflow preventive body. In the method for cleaning a floating filter medium, the floating filter medium 2 is filled under the filter medium outflow prevention body, the water level is reduced so that the water level is slightly below the outflow prevention means, and a fluid is ejected from the cleaning means. Since the floating filter medium is washed, only a small amount of wastewater is required for washing, and the treatment of the wastewater can be easily performed. Alternatively, when a storage tank or the like for storing the wastewater is provided, it is sufficient to provide a small one.

[0015] The slightly lower portion of the filter medium outflow preventive element in the present invention is separated from the uppermost surface of the floating filter medium and the filter medium outflow preventive element so as not to be in contact with each other, and the floating filter medium is jetted from below. It is positioned below the filter medium outflow preventive element to such an extent that free flow is not prevented by the filter medium outflow preventive element when it is caused to flow by the fluid.

Furthermore, since the water level does not drop much when the floating filter medium 2 is washed, there is no danger that the floating filter medium 2 will flow out together with the drainage from the lower part of the apparatus main body, and a filter medium outflow preventer is provided below the floating filter medium. Becomes unnecessary.

[0017]

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 filter device main body, and a raw water introduction passage 5 for introducing raw water to be treated into the device main body 1 is connected to a lower portion of the filter device main body 1, and a device is provided at an upper portion thereof. A treated water discharge port 6 for discharging treated water treated in the main body 1 to the outside is provided.

Reference numeral 2 denotes a cylindrical granular floating filter medium which floats on the surface of the treated water and is formed of a synthetic resin. The floating filter medium 2 may be a foamable synthetic resin such as expanded polystyrene, expanded polyethylene, expanded polypropylene or the like. It is preferably formed of a porous material having a specific gravity lower than that of water, such as water or fibrous synthetic resin, and the like. The floating filter medium 2 forms a floating filter medium layer 2a having a predetermined thickness above the treated water.

Reference numeral 3 denotes a filter medium outflow prevention member provided on the upper part of the apparatus main body 1. The filter medium outflow prevention body 3 is formed of, for example, a wire mesh or a plate having a large number of small holes formed therein. In order to prevent the floating filter medium 2 from flowing out together with the treated water from the port 6, it is provided below the treated water drain port 6. The filter medium outflow preventing body 3 may be any member as long as it allows water to pass through and does not allow the floating filter medium 2 to flow out.

Reference numeral 4 denotes an air diffuser as a cleaning means provided near the bottom of the apparatus main body 1. The air diffuser 4 is a blower.
The air is blown upward by 4a to wash the floating filter medium.

Reference numeral 7 denotes a bottom discharge passage provided with an openable / closable valve 7a. The bottom discharge passage 7 is provided near the bottom of the apparatus main body 1, and cleans sludge and the like settled at the bottom of the apparatus main body 1 at the bottom. It is provided to discharge with.

Next, the filtering apparatus 10 having the above-described configuration is used.
When the raw water is operated, first, raw water is introduced into the apparatus main body 1 from the raw water introduction passage 5 during normal raw water treatment.

Then, the suspended matter in the raw water is removed by contacting the suspended filter medium layer 2a floating on the water in an upward flow to filter suspended substances and the like in the raw water by the floating filter medium 2. The treated water thus treated is discharged to the outside through a treated water discharge port 6 at an upper portion of the apparatus main body 1.

At this time, although the water level A in the apparatus main body 1 is located near the treated water discharge port 6, the filter medium outflow prevention body 3
This prevents the floating filter medium 2 from flowing out together with the treated water.

Next, a case where the floating filter medium 2 is washed will be described. First, the valve 7a of the bottom discharge passage 7 is opened to discharge water in the apparatus main body 1 from the bottom discharge passage 7 to lower the water level as shown in FIG. As the water level at this time, the uppermost surface of the floating filter medium 2 located on the water surface A '
It is preferable that the water level is such that it is separated from the filter medium outflow preventing body 3 to such an extent that the floating medium 2 does not contact with the filter medium and the flow of the floating filter medium 2 is not blocked by the filter medium outflow prevention body 3.

Since the water level only needs to be lowered slightly in this manner, a large amount of drainage does not occur, and even when a storage tank or the like for storing drainage during washing is provided outside the apparatus main body 1, a small one is sufficient. .

At this time, it is sufficient that the water is drained to such an extent that the water level is slightly lowered. Therefore, even if a filter medium outflow preventive body or the like is not provided below the floating filter medium layer 2, the floating filter medium 2 is removed together with the drainage. There is no risk of being discharged from 1.

Then, air is blown from the air diffuser 4 by the blower 4a and blows out toward the upper floating filter medium layer 2a, and the floating filter medium layer 2 is caused to flow by the air, stirred and adhered to the floating filter medium 2. Remove suspended substances and the like.

At this time, the floating filter medium 2 is freely flowed up and down by the air without being blocked by the filter medium outflow preventing body 3 as described above, and is stirred, so that the washing efficiency is good.

Next, after the suspended filter medium 2 is washed in this way, the separated suspended substance is settled on the bottom surface of the apparatus main body 1 and the suspended substance is discharged from the bottom discharge passage 7. By slightly lowering the water level, there is no possibility that the suspended filter medium 2 and the suspended filter medium 2 will be discharged from the apparatus main body 1 even if a filter medium outflow prevention body or the like is not provided below the suspended filter medium layer 2.

Further, since no filter medium outflow preventive member or the like is provided below the floating filter medium layer 2 as described above, the separated suspended substances settle without being blocked on the bottom surface of the apparatus main body 1. It can be reliably discharged from the discharge path.

Thereafter, water may be jetted from the washing device 4 to backwash the floating filter medium 2 with water.

The washing of the floating filter medium 2 is repeated several times. After the washing step is completed, raw water is introduced again to start the above-mentioned treatment step.

Further, by repeating such washing, suspended substances may adhere to the air diffuser 4 provided at the bottom of the apparatus main body 1 and the vicinity of the bottom of the apparatus main body 1 and become dirty. Even in such a case, it is possible to easily clean the air diffusion device 4 because no obstacles such as the outflow prevention body are installed immediately above the air diffuser 4. In addition, there is an advantage that the air diffusion device 4 can be easily and easily performed at the time of failure or maintenance such as replacement.

In the above-described embodiment, the air diffuser for ejecting air is provided as the cleaning means. However, the cleaning means is not limited to the air diffuser, but means for ejecting water or water. And a device for simultaneously ejecting gas and gas. Further, when water is jetted out and used as a washing means, treated water may be used as the jetting water.

Further, in the above embodiment, the floating filter medium 2
Used a device that brought raw water into contact with
For example, raw water is introduced from the upper part of the apparatus main body 1 and the floating filter medium 2 is introduced.
May be a filter device configured to contact the device with a downward flow.

Further, in the above embodiment, the floating filter medium 2 is formed of granular synthetic resin or the like. However, such a filter medium may be, for example, one having microorganisms supported on the surface or a shape suitable for various filtration. May be formed.

In addition, specific configurations of the apparatus main body 1 and the filter medium outflow prevention body 3 can be freely changed within the range intended by the present invention.

[0040]

As described above, according to the method for cleaning a floating filter medium of the present invention, it is possible to surely prevent the loss of the floating filter medium and to reduce the size of the filtration device while maintaining a high cleaning effect. Thus, manufacturing and installation costs can be reduced.

[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.

FIG. 2 is a schematic front view showing a state when the floating filter medium is washed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Device main body 2 ... Floating filter medium 2a ... Floating filter medium layer 3 ... Filter medium outflow prevention body

Claims (2)

[Claims] The present invention has a filter medium outflow preventing member for preventing the floating filter medium (2) from flowing out to the upper side, and a filter medium outflow preventing body (3) under the floating filter medium (2). In the method for cleaning a floating filter medium floating in an apparatus main body (1) provided with a cleaning means, the floating filter medium is provided below the filter medium outflow prevention body (3).
(2), drained from the lower part of the apparatus body (1) so that the water level is slightly below the outflow prevention means (3), and further, the fluid is jetted out from the washing means to wash the floating filter medium. A method for cleaning a floating filter medium, comprising: 2. A filter device in which a floating filter medium (2) is filled inside a device body (1), wherein a filter medium outflow prevention member is provided above the floating filter medium (2), and the floating filter medium (2) is A filtering device, wherein a washing means is provided on a lower side without a filter material outflow preventing body.