JP2679531B2 - Filtration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates relates to a filtration device such as a biological membrane filtration apparatus, a filtration device having an improved supply mechanism backwash water especially.

[0002]

2. Description of the Related Art As is well known (for example, Japanese Patent Publication No. 3-77000), a biofilm filtration device is provided with a water tank, a biofilm filter installed in the water tank, and a lower side of the biofilm filter bed. And an air diffuser that is installed. A schematic configuration of a conventional biofilm filtration device and its operation will be described with reference to FIG.

In FIG. 3, a biofilm filter bed 12 is installed in a water tank 10, and an air diffuser 14 is provided below the biofilm filter bed 12.
Is installed. In order to carry out backwashing of the biofilm filter bed 12, backwash water can be introduced from the backwash pump 18 to the bottom of the water tank 10 through the backwash pipe (pipe for supplying backwash water) 16. The backwash pipe 16 is connected in the middle of the advection pipe 20.

Raw water is supplied to the water tank 10 from a raw water supply pipe 22, comes into contact with the biological membrane filter bed 12, is biologically processed, and is filtered by the filter bed 12. The treated water that has passed through the filter bed 12 is discharged through the advection pipe 20. In the case of aerobic biological treatment, air is supplied from the air diffuser 14 throughout the biological treatment.

As the biological treatment progresses, the biofilm filter bed 12
The water resistance of the river will increase. Then, Fig. 3 (1)
As shown in, the water level above the biofilm filter bed 12 rises. When the water level detected by the water level sensor 24 reaches or exceeds a predetermined water level, backwashing is performed. That is, first, the drain pipe 26 connected to the water tank 10 at the upper portion of the biofilm filter bed 12.
The drainage valve 28 of the above is opened to lower the water level above the biofilm filter bed 12.

After the water has been sufficiently drained as shown in FIG. 3 (2), the drain valve 28 is closed, and then air or other gas is sent from the diffuser pipe 14 to adhere to the biofilm filter bed 12. Reduces biofilms and sludge present by removing air bubbles.

Then, as shown in FIG. 3 (4), the backwash pump 18 is operated to introduce the backwash water into the bottom of the water tank 10 and remove the stripped biofilm and sludge together with the backwash water. Floor 1
Drain above 2. As a result, as shown in FIG. 5, water containing a large amount of the separated biofilm and sludge collects on the upper side of the biofilm filter bed 12, so the drain valve 28 is opened and the water is discharged.

As a result, as shown in FIG. 3 (6), the initial state is restored, and raw water is again supplied from the raw water supply pipe 22 to perform biological treatment. Note that the advection valve 30 provided in the advection pipe 20 is opened during the biological treatment. When the backwash water is introduced into the water tank 10 by operating the backwash pump 18, the advection valve 30 is kept closed to prevent the backwash water from flowing in the downstream direction of the advection pipe 20. .

[0009]

DISCLOSURE OF THE INVENTION In the above conventional filtering device, the drain valve 28 and the advection valve 30 are required. The environment in which the valves 28 and 30 are installed is a highly corrosive environment where the concentration of corrosive gas such as hydrogen sulfide is high, and it is a place where it is difficult to inspect and repair the valves. Is normal. Therefore, the drain valve 2
8 and the advection valve 30 are impaired in durability, and it is difficult to inspect and repair them.

[0010]

The filtration device of the present invention comprises a water tank, a filter bed installed in the water tank, an air diffuser provided below the filter bed, and a lower portion of the water tank. In a filtering device having an advection pipe for extracting water and a backwash water supply pipe connected to the advection pipe, an ejector is provided in the middle of the advection pipe, and the backwash water supply pipe is connected to the ejector. Connected to the working water inlet of the ejector, a part of the advection pipe upstream of the ejector is connected to the actuating water outlet of the ejector, and the negative pressure suction port of the ejector is downstream of the ejector of the advection pipe. It is characterized by connecting the part of.

[0011]

In the filtering apparatus of the present invention, when the backwash water is introduced into the lower part of the water tank through the ejector, the negative pressure generated in the ejector serves to suck the water in the advection pipe on the downstream side of the ejector. As a result, even if the conventionally used advection valve is omitted, the backwash water will not flow out to the downstream side of the advection pipe. That is, according to the filtration device of the present invention , the advection valve can be omitted.

[0012]

Embodiments will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing the configuration of a biofilm filtration device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of an ejector portion of the embodiment device.

Also in this embodiment, the biofilm filter bed 12 is installed in the water tank 10 and the air diffuser 14 is installed below it. Raw water is supplied from the raw water supply pipe 22 into the water tank 10, and the treated water is taken out through the advection pipe 20. In the present embodiment, the biologically treated water is once introduced into the backwash water tank 32, and the backwash pump 18 which is an underwater pump is installed in the backwash water tank 32.

In this embodiment, all of the drain pipe 26, drain valve 28 and advection valve 30 of the conventional device shown in FIG. 3 are omitted. Instead, the ejector 34 is installed in the middle of the advection pipe 20, and the backwash pipe 16 is connected to the working water introduction port 36 of the ejector 34. A portion of the advection pipe 20 downstream of the ejector 34 is connected to the negative pressure suction port 38 of the ejector 34, and a portion of the advection pipe 20 upstream of the ejector 34 is connected to the working water outlet 40 of the ejector 34. It is connected.

An air lift pump 42 is installed in the water tank 10.
Is installed. In the air lift pump 42, the suction port 44 is opened on the upper side of the biofilm filter bed 12, a short rising part 46 rises from the suction port 44, and then a falling part 48 and a long rising part 50 are passed. To the discharge section 52. A pipe 54 for introducing air is connected to the lower portion of the rising portion 50.

In the biofilm filtration device constructed as described above, the raw water supplied from the raw water supply pipe 22 comes into contact with the biofilm filter bed 12, and is subjected to biological treatment and filtration treatment. The treated water is taken out to the backwash water tank 32 through the advection pipe 20.

Biofilm The biofilm of the filter bed 12 grows and the aquarium 1
When the water level in 0 becomes equal to or higher than the specified water level, the raw water supply is temporarily stopped based on the signal from the water level sensor 24, and air or other gas is supplied to the pipe 54 to operate the air lift pump 42. Let As a result, the aquarium 10
The water level inside drops to the level of the suction port 44 of the air lift pump 42. Therefore, air or other gas is ejected from the air diffuser 14 to remove excess biofilm from the biofilm filter bed 12,
Peel off like rubbing with bubbles. Then backwash pump 1
8 is operated, backwash water is introduced into the water tank 10, and the biofilm stripped off from the biofilm filter bed 12 is washed with the backwash water to the filter bed 1
Carry above 2.

Then, the air lift pump 42 is operated again to discharge the water in the filter bed 12 out of the water tank 10.

If necessary, backwash water is introduced and drained by the air lift pump 42 repeatedly to sufficiently discharge the peeled biofilm out of the water tank 10.

After the backwashing of the biological membrane filter bed 12 is completed, raw water is again supplied from the raw water supply pipe 22 to perform biological treatment and filtration treatment.

In this embodiment, as described above, the drain valve and advection valve are unnecessary. Therefore, the durability of the device is extremely high. Since the ejector 34 is provided,
The backwash pump 18 is operated to move the backwash pipe 16 to the water tank 10.
Even when the backwash water is introduced into the inside, the backwash water does not flow out toward the downstream side of the advection pipe. That is, the ejector 34
Since the downstream side of the advection pipe 20 is connected to the negative pressure suction port 38, the water in the advection pipe 20 on the downstream side is sucked toward the ejector 34 when the backwash water is introduced into the ejector 34. The backwash water does not flow out toward the downstream side of the advection pipe.

In the above embodiment, backwashing is performed when the water level detected by the water level sensor 24 reaches a predetermined water level.
You may perform backwash regularly or at any time.

In the above embodiment, the air lift pump 42 extends inside the biofilm filter bed 12, but the air lift pump 42 may be arranged outside the water tank 10.

The apparatus of the present invention can be applied to both aerobic biofilm treatment and anaerobic biofilm treatment. The present invention can also be applied to a filtration device having a filter bed (for example, sand or activated carbon) other than the biofilm filter bed.

[0025]

The filter device of the present invention does not require the advection valve, which has been conventionally required.

As described above, since the advection valve, which is relatively susceptible to failure, is omitted, the device of the present invention is extremely durable. Also, because you can save the trouble of checking and repairing the advection valve,
The device of the present invention is extremely easy to maintain.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a biofilm filtration device according to an embodiment of the present invention.

FIG. 2 is a sectional view of an ejector portion.

FIG. 3 is a system diagram of a conventional biofilm filtration device.

[Explanation of symbols]

 10 Water Tank 12 Biofilm Filter Bed 14 Diffuser Pipe 16 Backwash Pipe 18 Backwash Pump 20 Advection Pipe 22 Raw Water Supply Pipe 26 Drain Pipe 28 Drain Valve 30 Advection Pipe 34 Ejector 36 Working Water Inlet 38 Negative Pressure Suction Port 40 Working Water Outlet 42 Air lift pump

Claims (1)

(57) [Claims] 1. A water tank, and a filter bed installed in the water tank,
In a filter device having an air diffuser provided on the lower side of the filter bed, an advection pipe for extracting water from the lower portion of the water tank, and a backwash water supply pipe connected to the advection pipe, An ejector is provided in the middle of the advection pipe, the backwash water supply pipe is connected to a working water inlet of the ejector, and a portion of the advection pipe upstream of the ejector is connected to a working water outlet of the ejector. The negative pressure suction port of the ejector is connected to a part of the advection pipe on the downstream side of the ejector.