JPH0810579A - Filtration method and device therefor - Google Patents

Abstract

PURPOSE:To use a simple, compact and fault-reduced device and to provide a filtration method using a filter membrane capable of being easily operated by vacuum-filtering raw water with a filter using a porous filter membrane and a pump and backwashing the filter under pressure with the pump and cleaning water. CONSTITUTION:The raw water is vacuum-filtered with a filter 1 using a porous filter membrane and a pump 3, and the filter 1 is backwashed under pressure with the pump 3 and cleaning water. The raw water is sucked in from the raw water inlet side of the filter 1 by the pump 3 in the raw water filtering cycle, and the filtered water is sent to the desired point of use from the delivery side. Cleaning water is sucked in from a cleaning water feed pipeline 7 by the pump 3 and sent to the filtered water outlet side of the filter 1 from the delivery side to backwash the porous filter membrane in the filter 1 backwashing cycle, and the waste water is discharged outside the system. Consequently, only one pump is used instead of the two in the conventional process, the equipment cost is reduced, the device is made compact, and the operation is simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filtration method and a filtration device, and more particularly to a filtration method and a filtration device using a porous filtration membrane. The porous filtration membrane used here is a porous porous membrane having a pore size of about 1 nm to 20 μm, which is used as a microfiltration membrane or an ultrafiltration membrane.

[0002]

2. Description of the Related Art Conventionally, in order to supply and filter raw water to the above-mentioned filter, a pump is provided on the upstream side of the filter, that is, the raw water supply side, and filtration is carried out under pressure. FIG. 2 is a flow sheet showing a basic example of a conventional filtration system using a porous filtration membrane. A filtration method and a filtration device using a conventional porous filtration membrane will be briefly described with reference to the drawings. A raw water pump 23 is provided between the raw water storage tank 22 and the upstream side of the filter 21 using the porous filtration membrane to filter the raw water.
1, was filtered by passing through the porous filtration membrane with the discharge pressure of the raw water pump 23, and was fed to the filtered water storage tank 24.
Then, a backwash pump 25 is provided on the downstream side of the filter 21, and when the separated solids or the like clog the filtration membrane, the raw water supply by the pump 23 is stopped, and the backwash pump 2
5, the filtered water in the filtered water storage tank 24 is sent in reverse to the filtered water outlet side of the filter 21, the porous filtration membrane is backwashed, and the drainage thereof is discharged from the discharge pipe 26 to the outside of the system. Was there.

[0003]

The pursuit of simpler devices and easier operation is no exception in filtration. The present invention has been completed for the purpose of providing a filtration method using a porous filtration membrane which is simple, compact, and has few troubles and which can be easily operated.

[0004]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention performs vacuum filtration of raw water using a filter using a porous filtration membrane and a pump, and There is provided a filtration method characterized in that the filter is backwashed under pressure with.

As a preferred embodiment of this filtration method, a pump is provided on the filtered water outlet side of the filter using the porous filtration membrane, and the suction side of the pump, the filtered water outlet side of the filter and the washing water supply pipe are provided. , Respectively, through the valve; the discharge side of the pump, the filtered water outlet side of the filter and the filtered water pipe are respectively connected through valves; in the raw water filtration cycle, the suction side of the pump and the filtration of the filter are connected. Open the valve to the water outlet side, close the valve to the wash water supply pipe, open the valve to the discharge side and the filtered water pipe, and open the valve to the filtered water outlet side of the filter. Close and pump the raw water from the raw water inlet side of the filter by the pump to filter the obtained filtered water from the discharge side to the desired destination; in the backwash cycle of the filter, the suction side of the pump and the filter Close the valve between the filtered water outlet side of
Open the valve between the cleaning water supply pipe, close the valve between the discharge side and the filtered water pipe, open the valve between the filtered water outlet side of the filter, and wash from the cleaning water supply pipe by the pump. A method of sucking water, sending it from the discharge side to the filtered water outlet side of the filter to backwash the porous filtration membrane, and discharging the drainage from the raw water inlet side to the outside of the system can be mentioned.

Further, it includes a filter using a porous filtration membrane and a pump provided on the filtered water outlet side of the filter, and the suction side of the pump, the filtered water outlet side of the filter and the washing water supply pipe are respectively provided. Connected via a valve, the discharge side of the pump, the filtered water outlet side of the filter and the filtered water piping are connected via a valve respectively, and the raw water inlet side of the filter is connected to the backwash drainage through the valve. Provided is a filtration device having a discharge pipe connected thereto. The above valve is not limited to a two-way valve, and a three-way valve or the like may be used.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and Functions The filtration method and filtration apparatus of the present invention will be described below with reference to the drawings, while showing embodiments. FIG. 1 is a schematic flow sheet showing a preferred embodiment of the present invention. The present invention is a filtration method that uses a filter 1 that uses a porous porous filtration membrane, and includes so-called microfiltration membranes and ultrafiltration membranes as the porous filtration membrane. Generally, the case of using a porous membrane having a pore size of 0.01 to 20 μm is called microfiltration. Membranes used for microfiltration membranes include cellulose derivatives such as cellulose acetate, organic polymers such as polysulfone, polyvinyl chloride, acrylic resin, polytetrafluoroethylene and polypropylene, and porous membranes such as porous ceramics. . These porous membranes can be made into a pleated shape, such as a cartridge type spirally wound with a support material, a hollow fiber bundle type, or the like, but any form can be selected according to the conditions of the implementation environment. .

Ultrafiltration membranes generally have a pore size of 1-10.
^This refers to a ⁴ nm porous filtration membrane, and is used, for example, to remove colloidal particles in raw water and proteins close thereto. As the ultrafiltration membrane, an organic membrane such as polyacrylonitrile or polysulfone, an inorganic membrane using graphite or porous ceramics, or the like can be used.
The shape and distribution method of the module conforms to the above-mentioned microfiltration step. The pump 3 used in the present invention employs a pump having a large suction pressure in order to give a sufficient filtration pressure.

In the present invention, a pump 3 for applying a filtration pressure is provided on the downstream side of the filter 1, that is, the filtered water outlet side, and the pump 3 is used to suck the raw water from the raw water storage tank 2 or the like. Then, it is filtered under reduced pressure in the filter 1 and the filtered water is fed into the filtered water storage tank 4 or the like. When the filter 1 becomes clogged, the pump 3 is used to pump purified water such as the filtered water storage tank 4 into the filter 1 from the downstream side of the filter 1, that is, from the filtered water outlet side, and the porous The membrane is washed to remove clogging.

A preferred embodiment of the filtration method of the present invention will be described. In this embodiment, a three-way valve is used as the valve. The suction side of the pump 3, the filtered water outlet side of the filter 1 and the wash water supply pipe 7 are connected via a three-way valve 5, and the discharged side is a filtered water storage tank and the filtered water outlet side of the filter 1 with a three-way valve. It is connected via 6. First, in the raw water filtration cycle, the three-way valve 5 is operated to open the space between the treated water outlet side of the filter 1 and the suction side of the pump 3, close the space between the wash water supply pipe 7 and the three-way valve 6. It is operated to open between the discharge side of the pump 3 and the filtered water storage tank 4, and close between the filtered water outlet side of the filter 1. The pump 3 is operated, the raw water is sucked from the raw water storage tank 2 to the raw water inlet side of the filter 1 to be filtered, and the obtained filtered water is sent from the discharge side to the filtered water storage tank 4. At this time, the drainage pipe 7 on the raw water inlet side is closed.

In the case of the backwash cycle of the filter 1, the three way valve 5 is closed between the filtered water outlet side of the filter 1 and the suction side of the pump, and is opened between the filtered water storage tank 4 and the three-way valve. Open between the discharge side of the pump 3 of the valve 6 and the treated water outlet side of the filter 1,
The gap between the filtered water storage tank 4 and the filtered water storage tank 4 is closed, the filtered filtered water is sucked in from the suction side, and is sent from the discharge side to the filtered water outlet side of the filter 1 to backwash the porous filtration membrane and the raw water inlet. The drainage is discharged from the drainage pipe 7 on the side to the outside of the system. The series of operations may be automatically switched at regular intervals. Also,
The filtration device using the porous filtration membrane of the present invention can be used in combination with other water purification devices such as a sand filtration device and a reverse osmosis membrane device.

[0012]

EFFECTS OF THE INVENTION By using the filtration method and the filtration device using the porous filtration membrane of the present invention, only two pumps, which are conventionally required, can be used, the facility cost can be reduced, and the device can be constructed compactly. can do. The operation is simple.

[Brief description of drawings]

FIG. 1 is a schematic flow sheet showing a preferred embodiment of the present invention.

FIG. 2 is a schematic flow sheet showing a basic example of a filtration device using a conventional porous filtration membrane.

[Explanation of symbols]

1: Filter 2: Raw water storage tank 3: Pump 4: Filtered water storage tank 5: Pump suction side three-way valve 6: Pump discharge side three-way valve 7: Drainage pipe 21: Filter 22: Raw water storage tank 23: Raw water pump 24: Filtered water Storage tank 25: Backwash pump 26: Waste water discharge pipe

Claims (3)

[Claims] 1. A filtration characterized in that raw water is filtered under reduced pressure using a filter using a porous filtration membrane and a pump, and the filter is backwashed under pressure using the pump and washing water. Method. 2. A pump is provided on the filtered water outlet side of a filter using a porous filtration membrane, and the suction side of the pump, the filtered water outlet side of the filter and the washing water supply pipe are connected via valves, respectively. , The discharge side of the pump, the filtered water outlet side of the filter and the filtered water pipe are connected via valves respectively, and in the raw water filtration cycle, the valve between the suction side of the pump and the filtered water outlet side of the filter is connected. Open, close the valve between the wash water supply pipe, open the valve between the discharge side and the filtered water pipe, close the valve between the filtered water outlet side of the filter, by the pump,
The raw water is sucked from the raw water inlet side of the filter to be filtered, the obtained filtered water is sent from the discharge side to the desired destination, and in the backwash cycle of the filter, the suction side of the pump and the filtered water outlet side of the filter The valve between the washing water supply pipe and the flush water supply pipe, the valve between the discharge side and the filtered water pipe, and the valve between the filtered water outlet side of the filter and the pump. , Sucks the wash water from the wash water supply pipe, sends it from the discharge side to the filtered water outlet side of the filter to backwash the porous filtration membrane,
The filtration method is characterized in that wastewater is discharged from the raw water inlet side to the outside of the system. 3. A filter using a porous filtration membrane and a pump provided on the filtered water outlet side of the filter, wherein the suction side of the pump, the filtered water outlet side of the filter and the wash water supply pipe are respectively provided. Connected via a valve, the discharge side of the pump, the filtered water outlet side of the filter and the filtered water pipe are connected via a valve respectively, and the raw water inlet side of the filter is connected to the backwash drainage via the valve. A filtration device, to which a discharge pipe is connected.