JP2001259381A - Membrane filter apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently perform the cleaning of a filter unit in a membrane filter apparatus wherein spiral membrane modules are arranged in a multistage fashion and concentrated water from the membrane module on a front stage side is utilized as raw water of the membrane module on a rear stage side. SOLUTION: Raw water flows through a first stage filter unit 10 from below to above and transmitted water is taken out of pipings 3, 4. Concentrated water is introduced into a second stage unit 20 from connection piping 5 to flow from above to below and transmitted water is taken out through pipings 6, 4 while concentrated water is taken out of piping 5. Piping 30 for supplying air, washing water and a cleaning chemical liquid is connected to the connection piping 5 and pipings 40, 42 for discharging a cleaning waste fluid are connected to raw water introducing piping 2 and the concentrated water discharge piping 7. The filter units 10, 20 are arranged so that the axial directions thereof are vertical.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a membrane filtration device (membrane separation device) such as a microfiltration device, an ultrafiltration device, a nanofiltration device, a reverse osmosis membrane separation device. The present invention relates to a membrane filtration device provided with a spiral type membrane module. More specifically, the present invention relates to a membrane filtration device provided with a backwashing unit using gas.

[0002]

2. Description of the Related Art FIG. 4 is a partially exploded perspective view showing the structure of a conventional spiral type membrane module.

[0003] A plurality of bag-shaped separation membranes 2 on the outer periphery of the water collecting pipe 1 are wound around a mesh spacer 3 for forming a raw water flow path.

[0004] The water collecting pipe 1 is provided with a slit-like opening communicating with the inside and outside of the pipe. The separation membrane 2 has a bag shape,
The central part surrounds the water collection pipe 1. A channel material 4 made of a mesh spacer or the like is inserted inside the bag-shaped separation membrane 2, and the inside of the bag-shaped separation membrane (bag-shaped membrane) 2 is a permeated water channel.

[0005] A top ring 6 and an end ring 7 are provided at both ends of the wound body 5 of the bag-shaped membrane 2, and a brine seal 8 is provided around the outer periphery thereof.

[0006] The membrane module is housed in a pressure-resistant container, and the brine seal 8 contacts the inner peripheral surface of the pressure-resistant container in a watertight manner.

The raw water introduced from the front end of the pressure vessel is
From the front end face of the wound body 5, it flows into the raw water flow path between the bag-like membranes 2, flows along the mesh spacer 3 as it is in the longitudinal direction of the wound body 5, and concentrates from the rear end face of the wound body 5. Leaked as. While flowing through the raw water flow path, water permeates the bag-like membrane 2 and enters the inside thereof, flows along the flow path material 4 and flows through the water collecting pipe 1.
And is taken out of the pressure-resistant container from the rear end side of the water collecting pipe 1.

In such a membrane module, as the SS component adheres to the spacers 3 and the membrane surface and the microorganisms propagate with the passage of the water passage operation time, water flushing is performed periodically or as needed. Chemical cleaning, air backwashing, etc. are performed.

[0009]

SUMMARY OF THE INVENTION Spiral type membrane modules are installed in multiple stages, and concentrated water from a first stage (or front stage) membrane module is used as raw water for a second stage (or rear stage) membrane module. In a membrane filtration device designed to increase the utilization rate of water, when the above-mentioned air backwash is performed, SS components, microorganisms, etc., which have separated and flowed out from the downstream membrane module, are transferred to the spacers of the upstream membrane module. Get entangled.

An object of the present invention is to make it possible to efficiently perform gas cleaning in a membrane filtration device provided with such spiral membrane modules in multiple stages.

[0011]

The membrane filtration device of the present invention comprises:
A membrane filtration device comprising a plurality of filtration units,
A membrane filtration device provided with a connecting pipe for guiding concentrated water of a preceding filtration unit as raw water to a subsequent filtration unit, wherein each filtration unit is coaxially housed in a cylindrical pressure-resistant container and the pressure-resistant container. In the membrane filtration device provided with a spiral type membrane module, each filtration unit is disposed with the axial line direction up and down, and the filtration unit of the former stage and the filtration unit of the latter stage has a water flow direction. Upside down, the connection pipe connects the upper end or lower end of the upstream filtration unit and the downstream filtration unit, and a gas supply pipe for membrane module gas cleaning is connected to the connection pipe. In addition, there is provided a means for discharging the washing waste fluid from the opposite side of the end of the filtration unit of each stage to which the connection pipe is connected.

In such a membrane filtration device of the present invention, gas is supplied from the gas supply pipe to the filtration units at each stage through the connecting pipe, and each filtration unit is washed with the gas. This washing waste fluid is discharged from each filtration unit. The washing waste fluid of the subsequent filtration unit does not flow into the previous filtration unit.

According to the present invention, as means for discharging the cleaning waste fluid, a waste fluid discharge pipe connected to a pipe for introducing raw water to a preceding filtration unit and a concentrated water discharge pipe from a latter filtration unit are connected. It is preferable to provide a waste fluid discharge pipe.

In the present invention, each stage may be composed of only one filtration unit, or may be composed of a plurality of filtration units connected in parallel.

In the present invention, the membrane modules of the filtration units at each stage may be the same or different.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1, 2, and 3 are system diagrams of a membrane filtration device according to an embodiment of the present invention.

The membrane filtration device shown in FIG. 1 includes a first-stage filtration unit 10 and a second-stage filtration unit 20 in two stages.
The concentrated water from the first-stage filtration unit 10 is used as raw water for the second-stage filtration unit 20 through the connection pipe 5.

Each of the filtration units 10 and 20 includes a spiral-type membrane module 11 or 21 and a cylindrical pressure-resistant container 12 or 2.
2 are accommodated coaxially. Each of the spiral membrane modules 11 and 21 has the configuration shown in FIG. 4 in which a separation membrane is wound around the outer periphery of the water collecting pipes 13 and 23. Brine seals 14 and 24 are provided on the outer periphery of the membrane modules 11 and 21, respectively.

The filtration units 10 and 20 are arranged such that the axis of the membrane modules 11 and 21 is in the vertical direction. In FIG. 1, the collecting pipes 13, 23
Are arranged such that the permeated water outlet of the unit 10 is located on the upper end side of the units 10 and 20.

The raw water is introduced into the lower end of the first-stage filtration unit 10 through a raw water pump 1 and a raw water supply pipe 2, and undergoes a membrane separation process in a membrane module 11. The permeated water flows into the collecting pipe 13 and the pipe 3 for taking out the permeated water.
4 to be taken out.

The concentrated water is introduced into the upper end of the second-stage filtration unit 20 through a connection pipe 5 connecting the upper parts of the filtration units 10 and 20 to each other. Then, after being subjected to the membrane separation process, the permeated water is taken out from the water collecting pipe 23 through the permeated water taking out pipe 6 and the permeated water taking out pipe 4. The concentrated water is discharged from a concentrated water extracting pipe 7 connected to a lower end of the filtration unit 20.

A pipe 30 for supplying a cleaning fluid is connected to the connection pipe 5. For this pipe 30, an air supply pipe 31 having an on-off valve 32, a cleaning water supply pipe 33 having an on-off valve 34, and a cleaning liquid supply pipe 35 having an on-off valve 36 are provided. Is connected.

A pipe 40 for discharging the washing waste fluid branches off from the pipe 2 for introducing raw water, and the pipe 40 is provided with an on-off valve 41. Also, the second-stage filtration unit 20
From the concentrated water discharge pipe 7, there is branched a cleaning waste fluid discharge pipe 42 having an on-off valve 43.

After water is passed through the filtration units 10 and 20 for a predetermined time to perform a membrane separation treatment, one or more of the on-off valves 32, 34 and 36 are opened to open one of the air, the washing water, and the washing liquid. Alternatively, two or more are supplied to the filtration units 10 and 20.
Further, the on-off valves 41 and 43 are opened. As a result, the cleaning waste fluid flows out through the pipes 40 and 42. When air is introduced into the units 10 and 20 as the cleaning fluid, water retained in the units 10 and 20, especially in the membrane modules 11 and 21 can be pushed out to the pipes 40 and 42.

When the contamination of the membrane modules 11 and 21 is mainly caused by clay silt, a configuration in which air is introduced from above as shown in FIG. 1 is preferable. By introducing the air, a large shearing force acts on the interface where the retained water and the air come into contact, and the contaminants can be effectively separated from the film surface. This is due to the turbulence promotion of the water.

In the filtration units 10 and 20, since the wastewater flows vertically downward, the membrane modules 11 and 21 are formed.
The separation contaminant moves vertically downward through the gap between the spacers, and is efficiently discharged from the pipes 40 and 42. Further, even if the peeling contaminants are once captured by the net-shaped spacer, they are discharged together with the downward airflow.

When cleaning the membrane modules 11 and 21 with air, a cleaning chemical solution is added to the air to supply a chemical mixture mist or the like into the filtration units 10 and 20 to perform effective cleaning. Is possible.

In addition, washing water is supplied to the filtration units 10 and 20 instead of air, air and washing water are supplied to the filtration units 10 and 20 to perform washing in a gas-liquid mixed state, or washing water and washing water are supplied. The chemical solution is supplied and the membrane modules 11 and 12 are supplied.
Cleaning in various patterns such as cleaning 1 is possible.

FIG. 2 shows that the raw water is introduced from the upper end of the first-stage filtration unit 10 and the concentrated water from the first-stage filtration unit 10 is discharged from the lower end of the second-stage filtration unit 20 to the raw water of the second-stage filtration unit. 1 shows a membrane filtration device according to an embodiment configured to be introduced as a filter. As shown, connecting pipe 5
Connects the lower ends of the filtration units 10 and 20 to each other.

As in FIG. 1, raw water is supplied from a raw water pump 1 and a raw water introduction pipe 2 into the first stage filtration unit 10, and permeated water is taken out via pipes 3 and 4. The concentrated water is introduced from the connection pipe 5 to the lower end of the second-stage filtration unit 20, and undergoes a membrane separation process by the membrane module 21.

The permeated water is taken out through the pipes 6 and 4 for taking out the permeated water, and the concentrated water is taken out through the pipe 7.

As shown in FIG. 1, a pipe 30 for supplying a cleaning fluid is connected to the connecting pipe 5, and a pipe 31 for supplying air and a pipe 3 for supplying cleaning water are connected to the pipes 30, respectively.
3. A pipe 35 for supplying a cleaning solution is connected.

Further, a pipe 40 for discharging cleaning waste fluid is connected to the pipe 2 for introducing raw water, and a pipe 42 for discharging cleaning waste fluid is connected to the pipe 7 for discharging concentrated water. Other configurations in FIG. 2 are the same as those in FIG. 1, and the same reference numerals indicate the same parts.

In the membrane filtration device shown in FIG. 2, the membrane separation process and the cleaning of the membrane modules 11 and 21 can be performed in the same manner as in FIG. As shown in FIG.
The configuration in which air is introduced from below to 0 and 20 is suitable for use when the contamination of the membrane module is mainly caused by microorganisms.

In FIGS. 1 and 2 and FIG. 3 to be described next, the permeated water is taken out from the upper end side of each of the filtration units 10 and 20, but may be taken out from the lower end side.

In FIGS. 1 and 2, one filtration unit is arranged in each of the first and second stages, but a plurality of filtration units may be arranged in parallel as shown in FIG.

In the membrane filtration device shown in FIG. 3, three filtration units such as 10a, 10b and 10c are installed in parallel as a first stage filtration unit, and as shown in 20a and 20b as a second stage filtration unit. And two filtration units are installed in parallel.

Each of the pipes 2 for introducing raw water has a pipe 2
a, 2b, and 2c, and branch into filtration units 10a, 10c.
b, 10c. Each filtration unit 10a,
The permeated water of 10b, 10c flows into the pipes 3, 4 via the pipes 3a, 3b, 3c for taking out permeated water, respectively, and is taken out.

First-stage filtration units 10a, 10b, 10
The concentrated water of c is connected to pipes 5a and 5
b, 5c, flows into the connection pipe 5, and then branches through the pipes 5A, 5B to the second-stage filtration unit 2.
Raw water is introduced into the lower ends of 0a and 20b. The permeated water of the second-stage filtration units 20a, 20b is supplied to the pipes 6a, 6
B is taken out through the pipe 6 for taking out the permeated water and the pipe 4.

The connecting pipe 5 includes a pipe 30 for supplying a cleaning fluid.
Are connected to a pipe 2 for introducing raw water, and a pipe 40 for discharging a cleaning waste fluid is connected to the pipe 7 for taking out a concentration waste fluid, and a pipe 42 for discharging a cleaning waste fluid is connected to the pipe 7. The other configuration of FIG. 3 is the same as that of FIG. 2, and the same reference numerals indicate the same parts.

In FIG. 3, as in FIG.
Although the stage filtration unit is circulated downward and the second stage filtration unit is circulated upward, it is apparent that the water flow direction can be reversed as shown in FIG.

In FIG. 3, three units are arranged in the first tier and two units are arranged in the second tier. However, it is obvious that the number of arrangements may be other than shown.

[0043]

As described above, according to the present invention, there is provided a membrane filtration device in which filtration units are connected in two stages, and concentrated water of the filtration unit on the front side is introduced into the filtration unit on the downstream side as raw water. The washing of each filtration unit can be performed very efficiently. In this case, the washing waste fluid from the downstream filtration unit is discharged out of the apparatus without being introduced into the upstream filtration unit, so that the upstream filtration unit is not contaminated. In the present invention, by introducing a gas such as air from above or below at the time of cleaning, it is possible to move the stripped contaminants in the vertical direction and efficiently discharge the contaminated contaminants out of the system.

[Brief description of the drawings]

FIG. 1 is a system diagram of a membrane filtration device according to an embodiment.

FIG. 2 is a system diagram of a membrane filtration device according to another embodiment.

FIG. 3 is a system diagram of a membrane filtration device according to another embodiment.

FIG. 4 is a configuration diagram of a spiral type membrane module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Raw water pump 2 Raw water introduction pipe 3,4,6 Permeate extraction pipe 5 Connection pipe 7 Concentrated water discharge pipe 10,10a, 10b, 10c First stage filtration unit 20,20a, 20b Second stage filtration unit 11 , 21 Spiral type membrane module 12, 22 Pressure vessel 13, 23 Water collecting pipe 14, 24 Brine seal 30 Cleaning fluid supply pipe 40, 42 Cleaning waste fluid discharge pipe

Claims (3)

[Claims] 1. A membrane filtration device comprising a plurality of stages of filtration units, wherein the membrane filtration device is provided with a connecting pipe for leading concentrated water of a previous stage filtration unit as raw water to a subsequent stage filtration unit. The filtration unit is a membrane filtration device including a cylindrical pressure-resistant container and a spiral-type membrane module coaxially housed in the pressure-resistant container. And the water flow direction of the upstream filtration unit and the downstream filtration unit is upside down, and the connection pipe connects the upper ends or the lower ends of the upstream filtration unit and the downstream filtration unit. A gas supply pipe for cleaning the membrane module gas is connected to the connection pipe, and a hand for discharging the cleaning waste fluid from the end of the filtration unit at each stage opposite to the end where the connection pipe is connected. Membrane filtering device, wherein a is provided. 2. A waste fluid discharge pipe connected to a pipe for introducing raw water to the upstream filtration unit as a means for discharging the cleaning waste fluid, and a concentration from the downstream filtration unit. A membrane filtration device comprising a waste fluid discharge pipe connected to a water discharge pipe. 3. The method according to claim 1, wherein one step is provided for each stage.
A membrane filtration device, wherein a plurality of or a plurality of filtration units connected in parallel are arranged.