JPH0833806A - Cleaning and regeneration of filter medium - Google Patents

Abstract

PURPOSE:To discharge only a separated clog with cleaning water without carrying a filter medium away from a water collecting nozzle at the upper part at the time of cleaning and regenerating the specified clogged filter medium by agitating and dispersing the filter mediums and then passing cleaning water up ward through the filter medium bed. CONSTITUTION:A mat formed by laying two kinds of synthetic-resin filaments having a different m.p. on one another into a felt is cut to a square piece and used as a filter medium 3 packed in a closed tank 2. The thickness of the piece is controlled to 3-5mm and the one side to 10-50mm. The two kinds of filaments are joined with a heating means. The medium 3 is clogged when filtration is continued, and the pressure in the tank 2 is increased due to the clogging of the medium 3. The pressure increase is detected by a pressure switch 8, hence an agitating motor 9 is operated, and an impeller 10 is rotated. A treated water valve 6 is simultaneously closed, a water discharge valve 7 is opened, and the contaminated water contg. the clog is discharged outside the system.

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 and regenerating a filter material in a filter device for sewage produced in a sewage terminal treatment plant or the like.

[0002]

2. Description of the Related Art Conventionally, as a technique similar to this type of filthy water filtering device, there is a filtering device using a floatable filter medium as a filter medium. This filter uses a granular floating filter material that is much lighter than sewage.When the filter material becomes clogged, in order to wash and regenerate it, the filter material layer is agitated to loosen the filter material and separate the clogged material. After that, the clogging material heavier than the filter medium is allowed to settle, and the difference in specific gravity is used to discharge the wastewater to the outside of the system. Japanese Examined Patent Publication No. 2-22682 is one example.

[0003]

However, in the above-mentioned conventional technique, it is difficult to separate the clogging material by stirring the lightweight and fine granular filter medium, and in particular, the heavy clogging material separates and sediments. There was a drawback that it took time.

[0004]

The present invention is characterized in that a filter medium having a large unit filter medium and a large specific gravity is used as compared with the conventional filter medium described above, and in particular, washing is performed while stirring and draining. To do.

That is, the gist of the present invention is to make a felt-like mat by polymerizing two kinds of synthetic resin filaments having different melting points and having a thickness of 3 to 5 m.
/ M, a filter for sewage using a filter medium having a specific gravity of approximately 0.9, which is cut into a rectangular shape with one side of 10 to 50 m / m, and the filter medium is stirred and dispersed in washing and regenerating the clogged filter medium. After that, cleaning water is sent from the lower part of the filter medium layer, the cleaning water is passed through the filter medium layer, and the cleaning wastewater is discharged from above the filter medium layer to the outside of the system.

[0006]

In the present invention, the unit body of the filter medium is relatively large,
Moreover, since the specific gravity is large, it is easy to stir and the clogging matter is easily separated. The dispersed filter medium has a unit body of 3 to 5 m / m and a thickness of 10 to 50 m as compared with the conventional filter medium.
Since it is a large / m port, it does not flow out from the upper water collecting nozzle, and only the separated clogging can be taken out of the system by the washing water.

As is clear from the above description, the method according to the present invention immediately stirs the clogging filter medium after stirring the clogging filter medium, without waiting for the filter medium and waste water to separate and stand still as in the conventional method. The filtration cycle time can be greatly shortened by eliminating the stationary time. Specific examples of the method of the present invention will be described below with reference to the drawings.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 3 are flow sheet diagrams for explaining the operation process of a filtration device according to the present invention, FIG. 1 is a filtration process, and FIG. 2 is a process for stirring a clogged filter medium. Three
Indicates a washing process of the agitated filter medium. In the filtration process, the stock solution is press-fitted into the closed tank 2 by the supply pump 1, and the filter medium 3
After the impurities are captured and filtered by, the filtrate is taken out of the system from the treated water inlet 5 through the water collecting nozzle 4.
At this time, the treated water valve 6 is open and the discharge valve 7 is closed. Further, the filter medium 3 loaded in the closed tank 2 is
As shown in FIG. 4, a felt-shaped mat obtained by polymerizing two kinds of synthetic resin filaments having different melting points was cut into a square piece. Its size is 3 ~
5m / m, the side is configured to 10-50m / m,
A heating means is used to bond the two types of synthetic resin filaments.

Next, in the cleaning step shown in FIG. 2, the filter medium 3 is clogged when the above-described filtration operation is continued. The clogging of the filter material 3 increases the pressure in the tank 2. This increase in pressure is detected by the pressure switch 8, the stirring motor 9 operates, and the stirring blade 10 rotates. At the same time, the treated water valve 6 is closed and the drain valve 7 is opened. Then, the sewage that is agitated and contains the clogging is collected by the water collecting nozzle 4
Through the drainage port 11 to the outside of the system. At this time,
Since the filter medium 3 has a particle size of 10 to 50 m / m on one side, which is much larger than that of the conventional floating filter medium, it will not be washed away.

During this time, the stock solution is supplied from the supply pump 10 to push up the filter medium 3 to form a washed filter medium layer. When the clogging is washed away and the pressure in the closed tank 2 returns to a constant pressure, the drain valve 7 is closed and the treated water valve 6 is opened to restart the filtration operation. In addition, the supply of the undiluted solution is performed without stopping, and the drainage that has passed through the drainage valve 7 is S.P. S
You may open the drain valve 7 until it disappears.

The operation of the filtration device according to the present invention described above is shown in time charts as shown in FIGS.
In the one shown in FIG. 5, the operation process is roughly divided into three processes of filtration, washing and waste water, and in the one shown in FIG. 6, washing,
It is roughly divided into filtration and two steps, but in both cases of FIG. 5 and FIG. 6, the supply pump 1 is not stopped, that is,
As in the case of cleaning the filter medium in the conventional apparatus using the floating filter medium, the time for leaving the cleaning filter medium stationary is completely eliminated, and the cleaning regeneration time is greatly shortened. To give a specific example of the difference between the cleaning and regeneration times, even when the drainage step is performed after cleaning as shown in the time chart of FIG. 5, it is 4 minutes and 30 seconds, whereas in the apparatus using the conventional floating filter, Usually, 60 seconds for stirring, 40 seconds for standing, 240 seconds for drainage, 24 hours after drainage
It takes 10 minutes to add 0 seconds, which is a great reduction.

The time chart shown in FIG. 6 is for the case where a small amount of SS is allowed to be mixed in the filtrate at the start of the operation after cleaning regeneration, and is used when it is desired to reduce the amount of cleaning waste water. By eliminating the water time, the cleaning and regeneration time of the filter medium is further shortened as compared with that shown in FIG.

Since the filter medium washed and regenerated as described above is made of fine fiber material and has good water permeability, even SS (fine suspended particles) inside the filter medium is washed away, and when the filtration operation is restarted. The slow speed is 70 m / Hr. In the case of the conventional styrofoam granular filter media, this filtration speed is more than double the filtration speed after washing and regeneration at 30 m / Hr.

[0012]

As is apparent from the above description, the method according to the present invention enables highly efficient microfiltration by devising the filter medium, and in particular, the clogging filter medium is washed and regenerated. In doing so, the contaminants can be separated without stopping the supply of raw water, and the filtration efficiency can be remarkably improved as compared with the conventional filtration apparatus of this type.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of a filtration device used in the present invention.
The filtration operation state is shown.

FIG. 2 likewise shows a state during cleaning of the filter medium.

FIG. 3 also shows the state of waste water after cleaning the filter medium.

FIG. 4 is a perspective view of a filter medium used in the present invention.

FIG. 5 is a time chart drawing of a method according to the present invention.

FIG. 6 is a time chart drawing of another example of the method according to the present invention.

[Explanation of symbols]

 3 filter media

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B01D 29/08 530 C 540 A

Claims (1)

[Claims] 1. A felt-like mat obtained by polymerizing two kinds of synthetic resin filaments having different melting points is cut into a rectangular shape having a thickness of about 3 to 5 m / m and one side of 10 to 50 m / m. In the filthy water filtering device using the filter medium 3 having a specific gravity of approximately 0.90, when washing and regenerating the clogged filter medium 3, the filter medium 3 is stirred and dispersed, and then wash water is sent from the lower part of the filter medium layer to wash the same. A method for cleaning and regenerating a filter medium, characterized in that water is passed through the filter medium layer, and the cleaning wastewater is discharged to the outside of the system from above the filter medium layer.