JP3124174B2 - Water treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to water treatment such as wastewater, sewage, and purified water, and more particularly to a water treatment apparatus provided with a membrane separation device for separating solid and liquid in a treatment tank.

[0002]

2. Description of the Related Art Conventionally, there is a water treatment apparatus provided with a membrane separation device for separating solid and liquid in a treatment tank as shown in FIG. In FIG. 2, a plurality of processing tanks 1 are arranged in parallel, and a raw water supply pipe 2 for supplying raw water to each processing tank 1 is open. A membrane separator 3 is immersed in each processing tank 1 and an air diffuser 4 is disposed below the membrane separator 3. A blow device 5 is connected to the diffuser 4 via an air supply pipe 4 a. ing. The membrane separation device 3 has a plurality of membrane modules, and each membrane module is composed of a group of membrane elements arranged in parallel with an appropriate gap. The internal flow path of each membrane element finally communicates with the suction pipe 6 via the liquid collecting part, and the suction pipe 6 communicates with the suction port of the suction pump 8 via the main opening / closing valve 7. The discharge pipe 9 connected to the discharge port is connected to a treated water tank 10. One end of the backwash pipe 11 communicates with the suction pipe 6 on the upstream side of the main on-off valve 7, and the other end is opened in the treated water tank 10.
A back pressure washing pump 12 and a back washing valve 13 are interposed midway.

According to this configuration, an upward flow is generated by the aeration air aerated from the air diffuser 4, and the upward flow sweeps the membrane surface of the membrane separation device 3 to flow through the cake layer. Inhibit the formation of In this state, the solid-liquid of the water to be treated is separated by the membrane separation device 3 disposed in each treatment tank 1, and the membrane permeated water sucked by the suction pump 8 through the suction pipe 6 is treated as treated water through the discharge pipe 9. It leads to the treatment water tank 10.

During back pressure cleaning, the main opening / closing valve 7 is closed and the back cleaning valve 13 is opened.
Thus, the treated water in the treated water tank 10 is supplied to the membrane separation device 3 through the backwash pipe 6, and the backwash water is jetted from the inside to the outside of the membrane element to peel the cake layer.

[0005]

However, in the conventional configuration described above, the backwash water flow rate used during backpressure washing is:
The flow rate of the treated water at the time of membrane filtration is 3 to 5 times, and a large amount of flow is required to simultaneously wash a plurality of membrane separation devices arranged in a plurality of treatment tanks. Therefore, it is necessary to provide the back pressure washing pump 12 having a large rated flow rate.

[0006] The present invention is to solve the above problems,
An object of the present invention is to provide a water treatment apparatus that can reduce the size of a back pressure washing pump.

[0007]

In order to solve the above-mentioned problems, a water treatment apparatus according to the present invention comprises a plurality of membrane separators immersed in a treatment tank, which are suctioned through a suction pipe provided for each membrane separator. In a water treatment apparatus that drives suction by a pump and stores the suctioned membrane permeated water in a treatment water tank, an on-off valve is interposed in the middle of each suction pipe, and one end communicates with the treatment water tank via a back pressure washing pump. At the other end of the backwash pipe, a plurality of backwash branch pipes branching in correspondence with the respective suction pipes are provided, a backwash valve is interposed in each of the backwash pipes, and each backwash branch pipe is provided with a corresponding suction. In this configuration, the pipe is connected between the on-off valve and the membrane separation device.

[0008]

With the above-described structure, normally, each backwash valve is closed, and the suction pump is driven with each open / close valve opened, and the membrane permeated water is guided to the treated water tank by the suction pump.

At the time of back pressure washing, the on-off valve of the suction pipe communicating with the target membrane separation apparatus is closed, and the back washing valve of the backwash branch pipe communicating with the suction pipe is opened, and the back pressure washing pump is opened. Is driven, and the treated water in the treated water tank is pumped to the target membrane separation device through the backwashing pipe and the backwashing branch pipe by the backpressure washing pump to remove the cake layer adhering to the membrane surface of the membrane separation device.

When the back pressure cleaning of one membrane separation device is completed, the backwash valve of the backwash branch pipe corresponding to this membrane separation device is closed, and the on-off valve of the suction pipe is opened. Thereafter, the same operation is performed while sequentially changing the membrane separation apparatus to be subjected to the back pressure cleaning.

[0011] Therefore, since a plurality of membrane separation devices are individually back-washed with a time lag, back-pressure washing can be performed with a smaller amount of back-pressure washing water than in the past. The size can be reduced. Furthermore, even if the membrane separation processing by a plurality of membrane separation devices is not stopped entirely,
The back pressure cleaning of each membrane separation device can be performed, and the membrane separation process and the back pressure cleaning can be performed in parallel.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. The plurality of processing tanks 21a, 21b, 21c are arranged in parallel, and a raw water supply pipe 22 for supplying raw water is opened in each of the processing tanks 21a, 21b, 21c. The membrane separators 23a, 23b, and 23c are immersed in the processing tanks 21a, 21b, and 21c, respectively.
4b and 24c, and each of the diffuser tubes 24a, 24b and 24
B is connected to blow devices 26a, 26b, 26c via air supply tubes 25a, 25b, 25c.

Each of the membrane separation devices 23a, 23b and 23c has a plurality of membrane modules, and each membrane module comprises a group of membrane elements arranged in parallel with an appropriate gap. Suction tube 27 provided for each membrane separation device 23a, 23b, 23c
a, 27b, and 27c are connected at one end to the internal flow paths of the respective membrane elements, and the other ends are respectively opened / closed valves 28a, 28b,
It communicates with the collecting pipe 29 via 28c. Collecting pipe 29
Is connected to a suction port of the suction pump 30, and a discharge pipe 31 connected to a discharge port of the suction pump 30 is connected to a treated water tank 32.

The backwash pipe 33 has one end communicating with the treatment water tank 32 via a backwash pump 34, and the other end has a plurality of backwash branch pipes branched corresponding to the suction pipes 27a, 27b and 27c. 35a, 35b and 35c. Each backwash branch pipe 35a, 35b, 35c is provided with a backwash valve 36a, 36b,
The corresponding suction pipes 27a, 27b, 27c via 36c
And the on-off valves 28a, 28b, 28c and the membrane separation device 23
a, 23b, and 23c.

The operation of the above configuration will be described below.
Normally, an upward flow is generated by aeration air aerating from the air diffusers 24a, 24b, 24c, and this upward flow sweeps the film surfaces of the membrane separation devices 23a, 23b, 23c to flow into the cake layer. Inhibit the formation of In this state, the suction pump 30 is driven with each of the backwash valves 36a, 36b, and 36c closed and each of the on-off valves 28a, 28b, and 28c opened. By driving the suction pump 30, the membrane permeated water that has passed through the membrane elements of the membrane separation devices 23a, 23b, and 23c is removed by the suction pipes 27a and 27c.
b, 27 c, the collecting pipe 29, and the discharge pipe 31 are led to the treatment water tank 32.

At the time of back pressure washing, each of the membrane separation devices 23a, 23
3b and 23c are individually back-pressure washed. That is, the on-off valve 2 of the suction pipe 27a communicating with the target membrane separation device 23a.
8a is closed, and the back pressure cleaning pump 34 is driven in a state where the back washing valve 36a of the back washing branch pipe 35a communicating with the suction pipe 27a is opened, and the treated water in the treated water tank 32 is used as a target membrane separation device. 23a is a backwash pipe 33 and a backwash branch pipe 35a.
To remove the cake layer attached to the membrane surface of the membrane separation device 23a.

When the back pressure cleaning of the membrane separator 23a in one processing tank 21a is completed, the backwash valve 36a of the backwash branch pipe 35a corresponding to the membrane separator 23a is closed, and the suction pipe is closed. The on-off valve 28a of 27a is opened. Thereafter, the object of the back pressure cleaning is sequentially changed to another membrane separation device 23.
The same operation is performed while changing to b and 23c.

In this embodiment, a plurality of processing tanks 2 are used.
1a, 21b and 21c are individually separated into membrane separation devices 23a and 23
Although b and 23c are immersed, a plurality of membrane separation devices immersed in one treatment tank may be individually back-pressure washed.

[0019]

As described above, according to the present invention, a plurality of membrane separation devices are individually back-washed with a time lag. And the size of the back pressure washing pump can be reduced. Further, the back pressure cleaning of each of the membrane separation devices can be performed without stopping the whole of the membrane separation processes by the plurality of membrane separation devices, and the membrane separation process and the back pressure cleaning can be performed in parallel.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a water treatment apparatus showing one embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional water treatment apparatus.

[Explanation of symbols]

 21a, 21b, 21c Treatment tank 22 Raw water supply pipe 23a, 23b, 23c Membrane separation device 24a, 24b, 24c Aeration pipe 27a, 27b, 27c Suction pipe 28a, 28b, 28c Open / close valve 29 Collecting pipe 30 Suction pump 32 Processing water tank 33 Backwash pipe 34 Backpressure washing pump 35a, 35b, 35c Backwash branch pipe 36a, 36b, 36c Backwash valve

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshiya Ozaki 2-1-1 Nishijima, Nishiyodogawa-ku, Osaka-shi, Osaka Kubota Corporation New Yodogawa Plant (56) References JP-A-4-250831 (JP, A) Hira 4-61623 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 65/02 C02F 1/44

Claims (1)

(57) [Claims] 1. A water treatment in which a plurality of membrane separation devices immersed in a treatment tank are suction-driven by a suction pump via suction pipes arranged for each of the membrane separation devices, and the sucked membrane permeated water is stored in a treatment water tank. In the device, a plurality of on-off valves are provided in the middle of each suction pipe, and one end is branched to the other end side of the backwash pipe communicating with the treatment water tank via the backpressure washing pump, corresponding to each suction pipe. A backwashing branch pipe, a backwash valve is interposed in each of the backwash branch pipes, and each backwash branch pipe is connected to a corresponding suction pipe between the on-off valve and the membrane separation device. Processing equipment.