JPH07108111A - Cleaning method of filter medium in filter using floating filter medium - Google Patents

Abstract

PURPOSE:To shorten the cleaning time of a filter medium by stirring and dispersing the filter medium with a raw water supplied, jetting the raw after into the filter medium after discharging the water and taking out he sewage after cleaning the filter medium from the bottom part of a closed tank at the time of cleaning the filter medium in an upflow type filter of the raw water. CONSTITUTION:When the raw water fed to the tank 1 from a main supply pipe 10 through a valve V2, a supply pipe 7a and a pit 7 is ascending in a filter medium layer 4, a contained dirt is captured and the filtrate is taken out from a discharge pipe 6a through a water collecting nozzle 3. At the time of clogging by the filtering operation, the filter medium is separated by rotating a stirring propeller 8 while continuously supplying the raw water and at the same time, the dirt is separated and only the separated water is discharged through the valve V5. Next, the rotation of stirring propeller 8 is stopped and the filter medium separated from the dirt is floated to form the filter medium layer. After that, the valve V5 is closed and the raw water through a valve V1 is reversely fed into the filter medium layer 4 from the nozzle 3 and the dirt is discharged from the valve 3.

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 filter medium in a filter using a light-weight granular filter medium such as expanded polystyrene, which is washed and regenerated in a short time without stopping the supply of raw water. The purpose of the present invention is to provide a cleaning method that can be performed.

[0002]

2. Description of the Related Art As a method of cleaning a filter medium in a filter using this type of conventional floating filter medium, JP-A-63-185 is known.
There is 416. In this product, in order to wash the clogged filter medium, the supply of raw water is stopped, the filter medium is mechanically stirred to loosen the filter medium, and then a part of the dirty water is discharged.
Next, the raw water is supplied into the tank, stirred again, and then the waste water is discharged.

[0003]

That is, in the above-mentioned prior art, when cleaning the filter medium, the supply of the undiluted solution is stopped to wash a part of the filter medium, and then the undiluted solution is supplied to clean the entire filter medium. Since the cleaning is performed, it takes a long time to perform stirring and cleaning twice, and it takes a long time to discharge the cleaning wastewater and to inject the raw water to restart the operation. And
During this time, all filtration operations must be stopped.

[0004]

SUMMARY OF THE INVENTION The present invention has solved the above-mentioned conventional problems by using the following method, and the gist of the present invention is that the particles float in a closed tank. In an upward flow type filter of raw water, which is filled with a filter medium, is provided with a nozzle for removing the filtrate at the top of the closed tank, and is provided with an outlet for washing and draining the filter medium at the lower bottom thereof.
When washing the clogged filter medium, the clogged filter medium is stirred and dispersed while supplying raw water, the separated water is discharged from the nozzle 3, and then the raw water is ejected from the nozzle 3 into the filter medium.
The dirty water from which the filter medium has been washed is taken out from the discharge port at the bottom of the closed tank.

[0005]

According to the method of the present invention, since the raw water is used as the cleaning water for cleaning the filter medium, the supply of the raw water into the tank is not interrupted during the cleaning, and the filter medium and the filter medium are not interrupted. Rinse the washed and washed filter medium to discharge only the dirty water containing contaminants.During this time, the tank is not emptied, so immediately after the cleaning, immediately enter the filtration operation of the next stage. You can That is, it is possible to wash the filter medium in a much shorter time as compared with the case where the inside of the tank is emptied twice while worrying about the outflow of the filter medium. Below, based on the figure,
The present invention will be specifically described.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 is a closed tank, 2 is a partition plate, 3 is a water collecting nozzle mounted on the partition plate, 4 is a floating filter material layer, 5 is a filtrate reservoir, and 6a is a filtrate withdrawal pipe. , 6b is a waste water pipe, 7 is a pit for supplying raw water and discharging waste water,
Reference numeral 7a is a raw water supply pipe, 7b is a wastewater discharge pipe, 7c is a backwash raw water supply pipe, and 8 is a filter blade. In addition, the symbol V
Reference numerals 1 to V5 represent valves provided in the above-mentioned respective pipelines.

In the filter constructed as described above, filtration and washing of the filter medium are performed as follows. That is, in the case of filtration work, the raw water from the supply pipe 10 is supplied to the valve V
2, sent to the tank 1 through the supply pipe 7a and the pit 7.
Then, while rising in the filter medium layer 4, the contained contaminants are captured, and the filtrate is taken out of the machine through the water collecting nozzle 3 and the take-out pipe 6 a.

When the filter medium is clogged in the filtration operation as described above, the valve V4 is closed and the valve V5 is opened while the raw water is continuously supplied from the valve V2 to rotate the stirring blade 8. The stirring blade 8 disperses the filter medium and separates impurities, and only the separated water can be discharged to the outside of the machine through the valve V5.

Next, when the stirring blade 8 is stopped, the valve V2 is closed, and the valve V1 is opened, the filter medium from which the contaminants are separated floats in the tank 1 and the filter layer (filter layer) is obtained.
To form. The time required for the filter medium to float in the tank 1 to form the filter medium layer is extremely short as compared with the conventional time for draining dirty water from the tank. After separating the impurities in the filter medium layer as described above, the valve V5 is closed and the valve V3 is opened so that the raw water that has passed through the valve V1 flows from the nozzle 3 into the filter medium layer 4 (backflow). Then
At the same time as rinsing the filter medium layer 4, pit 7 and valve V3
It is possible to discharge the contaminants that have flowed out of the machine through the above and settled to the bottom of the tank 1 such as the pit 7. After discharging the contaminants, the valve V1 is closed and the valves V2 and V4 are opened, whereby the raw water rises in the closed tank and the filtered water can be obtained from the extraction pipe 6a.

That is, the present invention is characterized in that the filter medium from which impurities have been separated is rinsed with raw water, and at the same time the separated impurities are washed away by the raw water and discharged. In comparison with the conventional cleaning of the filter medium, the miscellaneous time on the filtration can be greatly shortened.

FIG. 2 shows the operating state of each valve and the stirring blade during the above-mentioned filtration work and cleaning of the filter medium. When the cleaning water is drained (when the valve V3 or V5 is open), the valve V is used.
1 shows that the valve V2 is opened, the raw water is supplied into the closed tank 1 and the inside of the closed tank is not empty, and the valve operation can be immediately performed to move to the next filtration operation.

[0012]

EFFECTS OF THE INVENTION As is clear from the above description, according to the present invention, in a filter using a floating filter medium, when the filter medium is clogged, the filter medium can be washed and regenerated without draining the raw water in the filtration tank. When this type of conventional filter is used for cleaning the filter medium,
By completely eliminating the time to drain the raw water from the tank and supply it again, it was possible to improve the operating rate of this kind of filter, especially when the filtered water is not used elsewhere, for example, for the treatment of discharged water. It has a great effect.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional side view of a filtration device using a floating filter medium used in the present invention.

FIG. 2 is a table showing the operating states of valves and stirring blades used in various parts when the filter according to the present invention is operated.

[Explanation of symbols]

 1 closed tank 3 nozzles

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location 8925-4D 540 A

Claims (1)

[Claims] 1. A closed tank 1 is filled with a particulate floating filter medium, a nozzle 3 for taking out filtrate is provided at the top of the closed tank 1, and a discharge port 7 for washing and draining the filter medium is provided at the lower bottom thereof. In washing the clogged filter medium in the upward flow filter of raw water, while supplying the raw water, the clogged filter medium is stirred and dispersed, and the separated water is drained from the nozzle 3 and then the raw water is filtered from the nozzle 3 into the filter medium. A method for cleaning a filter medium in a filter using a floating filter medium, characterized in that filth water, which has been washed with a filter medium and is washed out, is taken out from the lower bottom portion of the closed tank 1.