JPH07328352A - Filter device for settling tank - Google Patents

Abstract

PURPOSE:To prepare clear water by utilizing a head between a final settling tank and a flood way and filtering discharge water from the final settling tank in an organic soil water treatment facility such as a sewage. CONSTITUTION:A high water level outflow waterway 2a and a low water level outflow waterway 2b are formed by providing a weir plate 4 in an outflow waterway 2 of supernatant water of a settling tank, and the high water level outflow waterway 2a is connected to a raw water feed inlet of a filter device provided in the settling tank below the outflow waterway 2, while the low water level outflow waterway 2b is connected to an intake of filtrate in the filter device. Treated water in the settling tanks is fed to the filter device by the natural water level difference formed in the outflow waterway 2 and filtered therein to improve the quality of treated water in the settling tank without using power especially.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for filtering outflow water from a sedimentation basin installed for sewage treatment, industrial wastewater treatment and the like.

[0002]

2. Description of the Related Art Conventionally, filtration is carried out as a retreatment of secondary treated water by the activated sludge method of organic wastewater such as sewage, but it is common to filter the effluent of the sedimentation basin with a separately provided filtration device. Yes, a raw water pump is used to supply raw water to the filtration device.

[0003]

SUMMARY OF THE INVENTION In order to improve the quality of treated water in the final sedimentation basin, the present invention utilizes the inside of the sedimentation basin as a place for installing a filtering device, and particularly requires power in order to filter the whole quantity. The purpose of the present invention is to provide a device that can easily perform filtration without doing so.

[0004]

Therefore, according to the present invention, a weir plate is provided in the outflow channel of the treated water of the final settling basin to form a low channel and a high channel in the outflow channel, and the difference in the water levels is utilized. A filtering device installed in the settling basin is installed in the settling pond.More specifically, a weir plate is installed at the outflow canal of the treated water overflowing from the settling pond to form a high water level canal and a low water level canal. A filter is installed in the sedimentation basin below the outflow canal, and the raw water inlet of the filter is connected to the high water canal and the filtrate outlet of the filter is connected to the low water canal. It was done.

[0005]

Since the apparatus according to the present invention is configured as described above, the treated water that overflows from the settling basin to the outflow channel is blocked by the weir plate, and a high water level channel and a low level channel are formed in the outflow channel. A water channel is formed. Then, the overflow water (treated water) of the high water level canal is supplied to the filtration device at the lower part of the outflow water channel and filtered, and the filtrate can be taken out into the outflow water channel of the low water level through the outlet of the filtration device. .

That is, the treated water overflowed from the settling basin can be further filtered by a filtering device to obtain a filtrate with improved water quality, and the energy required for the filtration is still in the outflow channel. This is because of the head of the outflow channel obtained by the weir plate provided, and does not require a pump for supplying overflow water to the filtering device or a pipe attached thereto.

When the filter medium of the filter device is clogged by such an operation, the filter medium is washed and regenerated, but compared with the conventional device in which the filter device is provided separately from the sedimentation tank, only when the filter medium is backwashed and regenerated. Only a small amount of power is required by using pump power. Further, in the present invention, since the filtering device is installed in the sedimentation basin, the installation place of the filtering device is not required unlike the conventional case. Hereinafter, the present invention will be specifically described with reference to the drawings.

[0008]

EXAMPLE FIG. 1 is a vertical cross-sectional view of an example in which a filtering device is installed in a sedimentation basin below a treated water outflow channel, and a treated water outflow channel 2 is provided along a side wall at an upper part of the sedimentation basin 1. The water level H1 of the settling basin 1 is held by the overflow weir 3 so that the overflow water flows into the outflow channel 2.

A weir plate 4 is provided in the outflow water channel 2 along the longitudinal direction (flow direction) thereof, and a water level difference (H3-H4) is secured in the outflow water channel 2 by the weir plate 4.
The outflow water channel 2a on the high water level side is connected to the raw water supply port of the filtration apparatus, and the outflow water channel 2b on the low water level side is connected to the filtrate outlet of the filtration apparatus.

Next, the structure of the above filtering device will be described. In the figure, reference numeral 5 is a filtration tank, which is loaded with a granular floating filter material 6, and an inflow pipe 7 at the upper portion thereof is connected to the outflow water channel 2a on the high water level side.
And a supply nozzle pipe 7a is provided at the end of the inflow pipe 7. Further, a filtrate withdrawal pipe 9 is opened at the lower side of the filtration tank 5, and the upper end thereof is provided with the outflow water channel 2b on the low water level side.
It is opened inside.

Further, the separation tank 10 is formed at the bottom of the filtration tank 5 by partitioning it with the filtration chamber 5a, and the top of the conical ceiling wall of the separation tank 10 and the filtration chamber 5a are opened and closed via a float valve 11. While freely communicating with each other, a filter cleaning tube 12 is provided between the upper end of the filtration chamber 5a and the separation tank 10. Further, a drawing tube 13 is opened in the separation tank 10, and the drawing tube 12 is opened. Is connected to the extraction pump 14.

As shown in FIGS. 2 and 3, the float valve 11 has a spherical valve seat 11b formed in the lower portion for receiving the float ball 11a, and a radial groove 1 formed in the upper portion.
A spherical seat 11c having 1d is formed. The groove 11d provided in the seat 11c has a width that allows the particulate floating filter material 7 to communicate therewith.

The apparatus according to the present invention is constructed as described above, and the treated water from the settling basin 1 drops from the overflow weir 3 into the outflow water channel 2a on the high water level side and is supplied through the inflow pipe 7. It is supplied to the upper layer portion of the floating filter medium 6 by the nozzle tube 7a. Then, while flowing down through the floating filter material layer, the impurities are captured and filtered and accumulated in the filtration chamber 5a, rise in the take-out pipe 9, and are discharged from the low water level side outflow passage 2b to the outside of the system.

That is, in the apparatus according to the present invention, the treated water in the settling basin 1 is supplied to the filtration tank 5 by the water level difference H3-H4 obtained by the weir plate 4 provided in the outflow water channel 2 for further purification treatment. From the low water level side runoff channel 2b, COD, BO
It is possible to obtain clean water with reduced D, and does not require a supply pump, piping, etc., unlike a conventional filter device separately provided.

When the floating filter material layer is clogged by such a filtering operation, the water level H3 of the outflow water channel 2a rises, and when the water level reaches H2, it overflows from the dam plate 4. In this case, by operating the extraction pump 14 to remove the contaminated water in the separation tank 10, the clogged filter material in the upper layer of the floating filter material 6 flows down in the washing pipe 12, and the contaminants are included in the flow down. It can be peeled off. And separation room 1
In 0, the washing pipe 12 is opened in the separation chamber 10, and the flow path thereof is rapidly expanded, the flow velocity is reduced, heavy impurities settle, and the impurities are separated, and the light floating filter medium 6 is formed. Floating and heavy impurities can be taken out of the system by the extraction pump 14. At this time, the float valve 11 is closed by the suction of the separation chamber 10 so that the float ball 11a is settled.

The floating filter medium 6 from which the impurities have been separated floats and accumulates on the float valve 11 portion at the top of the separation chamber 10. As described above, the float ball 11a of the float valve 11 is settled by suction of the drawing pump 14. Since it is in contact with the valve seat 11b, the filtrate in the lower part of the filtration chamber 5a will not be drawn out.

In this way, when the clogging of the upper part of the floating filter medium layer is eliminated, the water level H3 of the outflow water channel 2a lowers. Therefore, the withdrawal pump 14 is stopped when the water level H3 reaches a predetermined water level. You can enter the filtration operation.

Then, by stopping the drawing pump 14, the float ball 11a floats and the float valve 11 is opened. From the opened float valve 11, the washed floating filter material 6 accumulated on the float valve 11 is seated 11c.
After entering the filtration chamber 5a through the groove 11d, the regenerated filter material layer can be formed by being distributed to the lower surface of the floating filter material layer.

The above-described filtration operation and filter material washing and regeneration operation can be automatically performed. That is, the extraction pump 14 is set to the water level H1 of the settling basin 1 and the water level H3 of the outflow water channel 2a.
If the filter medium layer is clogged to detect the water level difference with the water level and the water level in the outflow channel 2a rises, the rising pump level is detected and the extraction pump 1
4, the clogged upper layer filter medium can be pulled out and washed as described above, and when the clogging of the filter medium is eliminated in this way, the water level of the outflow water channel 2a lowers. It is possible to perform a normal filtration operation by detecting the above and stopping the extraction pump 14.

When the drawing pump 14 is stopped, the suction pressure in the separation chamber 10 is released and the float ball 1
As described above, 1a floats, the separation chamber 10 and the filtration chamber 5a communicate with each other, and the washed filter medium passes through the groove of the receiving seat 11c and is returned to the lower surface of the filter medium layer to form a regenerated filter medium layer. Is.

[0021]

As is apparent from the above description, the apparatus according to the present invention can be easily installed in an existing treatment facility in either a rectangular sedimentation tank or a circular sedimentation tank, and the energy required for the filtration is required. Uses the head between the settling basin and the discharge channel, and requires no energy other than cleaning and regeneration of the filter medium. Further, since the device according to the present invention is attached to the final settling basin and is installed so as to be overlapped with the discharge path, it does not require a special installation place. Further, even when newly installed, the quality of the discharged water can be improved by filtering the secondary treated water of the sewage by simply increasing the area of the conventional discharge passage.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a sedimentation tank filtration device according to the present invention.

FIG. 2 is a vertical sectional side view of a float valve of the device according to the present invention.

3 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

 1 Sedimentation basin 2 Outflow channel 2a Outflow channel on the high level side 2b Outflow channel on the low level side 4 Weir plate 5 Filtration tank

Claims (1)

[Claims] 1. A weir plate 4 is provided in an outflow channel 2 of treated water overflowing from a settling basin 1 to form a high water level channel 2a and a low water level channel 2b in the outflow channel 2, and below the outflow channel 2. A filtration device 5 is provided in the sedimentation basin 1 of
The apparatus for filtering sedimentation basin, characterized in that the raw water inlet is connected to the high water channel 2a, and the filtrate outlet of the filtering device 5 is connected to the low water channel 2b.