JPH0999223A - Membrane separation device by hollow tubular membrane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the packing ratio of a raw water permeable membrane and to make maintenance easy. SOLUTION: This device is provided with a water tank 20 storing a raw water, a lower drum 10, which has a raw water supply section 10' and an upper opening and is connected to the bottom of a water tank 20, a diffusion pipe 12 for supplying a gas to raw water supply section, a membrane element 21 in which the inside of a jacket is partitioned into a permeated water collecting section 24 and a raw water passage part 23 by housing many tubular hollow membranes 22 in the jacket 16 erected freely detachably in the lower drum and the bottom end of the raw water passage part 23 is made to communicate with the raw water supply section 10' and a upper drum 29, which is disposed above the jacket, connected to the upper part of the water tank 20 and for circulating a concentrated water, passed through the raw water passage part, from the jacekt to the water tank 20. The permeated water passing through the membrane is taken out from a permeated water collecting section to the outside.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an internal pressure type or external pressure type hollow tubular membrane housed inside an outer cylinder to separate raw water by an air lift while performing membrane separation and collect permeated water that has passed through the membrane. The present invention relates to a membrane separation device using a hollow tubular membrane that is watered.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional air-lift circulation type submerged membrane separator, in which an air-lift cylinder 2 is erected in the water of a treatment tank 1 to which raw water is supplied, and the air-lift cylinder 2 is provided at the upper end of the air-lift cylinder 2. A membrane module 4 is arranged in which a plurality of flat sheet membrane elements 3 having permeated water outlets 7 are arranged in a row in the front-rear direction with a flow path interval 6 maintained.

The air lift cylinder 2 has a rectangular cross section,
The cross-sectional area is constant from the upper end to the lower end. By diffusing air from the air diffusing device 5, a cross flow upward flow due to an air lift is generated in the flow path interval 6 between the opposed membrane surfaces of the flat sheet membrane element 3 constituting the membrane module 4 in the air lift cylinder 2, and the membrane surface The permeated water that permeates the membrane is obtained inside the flat sheet membrane elements 3 while preventing the formation of gel-like deposits on the inside of the flat sheet membrane elements 3, and the permeated water is connected to the outlets 7 of the flat sheet membrane elements 3 through the header pipes 8. Water is drawn by sucking with the pump P via the.

[0004]

However, in order to install the above-mentioned conventional apparatus, a processing tank is constructed, an air lift tube is erected inside the processing tank, the membrane module is supported on the air lift tube, and the tank bottom is installed. An air diffuser that floats air bubbles inside the air lift cylinder is installed and connected to a blower outside the tank by piping, and one flat membrane element that constitutes the membrane module is connected to the header pipe, and the header pipe and pump Need to be connected by piping, which is very troublesome to install.

Further, in order to increase the scale of the apparatus and increase the filling rate of the membrane for improving the treatment capacity of raw water, the number of flat membrane elements constituting the membrane module by arranging them in a row in the front-rear direction is increased. In addition, it is necessary to remodel the processing tank and the air lift cylinder in the front-rear direction, which is very time-consuming and requires a long construction period until completion, resulting in a very high cost.

Further, the flat sheet membrane element has a limitation in the size of the flat sheet membrane due to the problem of strength, and it is necessary to make the flat sheet membrane element in multiple stages in the vertical direction in order to increase the filling rate.
If the number of stages is increased, the installation structure and piping structure will become very complicated.
Further, in the immersion type membrane separation device, it is necessary to periodically take out the membrane module from the tank and wash or replace it, but since the membrane structure is complicated as described above, removal of the flat membrane element from the membrane module, It is difficult to install and very troublesome.

[0007]

The present invention was developed in order to solve the above-mentioned problems, and is a water tank for storing raw water therein, and a raw water supply chamber connected to the lower portion of the water tank. And a horizontal lower can body having an opening in a part of the upper surface thereof, an air diffuser provided inside the lower can body in the longitudinal direction thereof to supply gas into the raw water supply chamber, and the lower can body. A large number of hollow tubular membranes are housed inside an outer cylinder that is detachably erected with respect to the opening on the upper surface of the And a membrane element in which the lower end of the raw water flow passage communicates with the raw water supply chamber, and the concentrated water that has been passed through the raw water flow passage is connected to the upper part of the water tank and the upper part of the outer cylinder. It consists of a horizontal upper can body that circulates from the cylinder into the water tank. The raw water supplied to the chamber is made to flow upward along the hollow tubular membrane in the raw water flow passage of the membrane element by the gas supplied from the diffuser pipe, and the water that has passed through the raw water flow passage and comes out above is discharged. A membrane separation device using a hollow tubular membrane, wherein permeated water that has passed through the hollow tubular membrane and is circulated through the upper can body is collected from the permeated water collection chamber to the outside.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In the illustrated embodiment, 20 is a water tank for storing raw water therein, 10 is a cylindrical horizontal lower can body connected to the lower part of the water tank 20 and has an opening 11 in a part of its upper surface, and 12 is a lower can body. An air diffuser, which is supported by the support section on the inner lower circumference and is provided in the longitudinal direction of the can body.
Reference numeral 13 denotes an end plate that is attached to a flange provided at the end of the lower can body 10 to close the end of the lower can body 10 and form the inside of the lower can body 10 in the raw water supply chamber 10 ′. A communication port 15 for communicating with the air diffuser 12 is provided in the lower part of 13, and an air supply pipe from a blower or the like is connected to the communication port 15.

The end plate 13 is, for example, a quadrangle, and is brought into contact with the floor at one side of the quadrangle so that the lower cylindrical can body 10 can be stably supported in a horizontal state. A raw water supply port 14 formed at the bottom of the water tank 20 is connected to the other flange of the lower can body 10. The brim of the raw water supply port 14 has a quadrangular shape similar to the end plate 13, and has a cylindrical lower can body 1 which comes into contact with the floor at one side of a square.
0 is supported stably in a horizontal state.

An opening 1 provided in a part of the upper surface of the lower can body 10.
1. A flange is provided around 1, and the flange at the lower end of the outer cylinder 16 is mounted on the flange and mounted, and the outer cylinder 1 is placed on the opening 11.
6 is detachably set up. The lower can body 10 and the outer cylinder 1
6 is manufactured by blow molding of vinyl chloride, polypropylene or the like.

Reference numeral 21 is a membrane element in which a large number of hollow tubular membranes 22 are housed inside the outer cylinder 16. Then, on the outer cylinder 16 in which the membrane element 21 is inserted and arranged,
Horizontal upper can body 29 having a circulation port 17 and a continuous port 28
Is provided. The concentrated water introduction port 33 formed in the upper portion of the water tank 20 is connected to the circulation port 17 of the upper can body 29. on the other hand,
A blind plate 34 is attached to the connection port 28 of the upper can body 29 to seal it. The water tank 20 has a depth or height such that the water level of the raw water is located above the water level in the permeate collection chamber 24 of the membrane element 21.

The hollow tubular membrane 22 of the membrane element 21 used in the embodiment shown in FIGS. 1 and 2 allows raw water to pass through the hollow portion of the membrane, and permeate that has permeated through the membrane to the outside of the hollow tubular membrane 22. In this case, a large number of hollow tubular membranes 22 penetrate the upper end of the perforated disc-shaped upper tube sheet 25 of the membrane element 21 in this case,
The lower end penetrates the same lower tube sheet 26 and is arranged vertically.
Raw water flows from the bottom to the top in the hollow portion of the hollow tubular membrane 22 addressed to one. Therefore, the hollow portion of the hollow tubular membrane 22 addressed to one becomes the raw water flow path portion 23, and the inside of the outer cylinder 16 (the space around the hollow tubular membrane 22) closed by the upper and lower tube plates 25 and 26 permeates. It becomes the water collection room 24. Then, the upper tube sheet 25 and the lower tube sheet 2
At the center of 6, a permeated water outlet 27 that communicates with the permeated water collection chamber 24 is vertically provided.

As described above, in this embodiment, the internal pressure type hollow tubular membrane 22 is adopted. However, the present invention is not limited to this, and an external pressure type that obtains permeated water that has passed through the membrane from the outside in the hollow portion of the hollow tubular membrane is used. Alternatively, the inner side of the hollow tubular membrane is closed by the upper and lower tube sheets 25.

In the embodiment shown in FIGS. 1 and 2, the permeated water extraction pipe 18 is provided in the longitudinal direction along the upper inner circumference of the lower can body 10 in the same manner as the diffuser pipe 12 in a state of being suspended by a support portion. At the upper part of the end plate 13, there is provided a communication port 19 with the extraction pipe 18. The permeated water outlet 18 is provided with a branch port 30 projecting upward toward the center of the opening 11 provided on the upper surface of the lower can body 10. Therefore,
The permeated water outlet 27 projecting downward from the lower tube sheet 26 of the membrane element 21 using the internal pressure type hollow tubular membrane 22 is fitted and connected to the branch port 30 to connect the membrane element 21 to the outer cylinder 16 It can be supported in a state of being inserted inside. An exhaust pipe 31 is connected to the outlet 27 that projects upward from the upper tube plate 25 of the membrane element 21. The exhaust pipe 31 has an opening / closing valve 32 in a portion protruding upward from the upper end of the outer cylinder 16.

To collect permeated water, the lower can body 10 is connected to the raw water supply port 14 of the water tank 20, the upper can body 29 is connected to the concentrated water inlet port 33 of the water tank 20, and the diffuser pipe 12 is connected.
An air supply pipe from a blower or the like is connected to the communication port 15 of the end plate 13 that communicates with the end plate 13 that communicates with the permeated water extraction pipe 18.
A suction pipe from a suction pump is connected to the communication port 19 of 1, the opening / closing valve 32 of the exhaust pipe 31 is closed, and the suction pump and the blower are operated. At that time, the raw water is supplied from the raw water supply port 14 of the water tank 20 into the raw water supply chamber 10 ′ of the lower can body 10 in the raw water inside the water tank 20 and the permeated water collection chamber 24 without providing a raw water supply pump. The water level difference L from the permeated water is also the driving force for the membrane permeation.

Raw water and air bubbles from the air diffuser 12 are supplied to the raw water supply chamber 10 'in the lower can body 10, and the air lift action of the air bubbles causes the raw water to be hollow in the hollow tubular membrane 22 addressed to one of the membrane elements 21. Upward flow at a high speed in contact with the inner circumference of the membrane. In the permeate collection chamber 24 inside the membrane element 21,
Negative pressure by suction pump is permeated water extraction pipe 18, branch port 3
0, since it acts through the permeated water outlet 27, the permeated water that can pass through the membrane in the raw water flowing upward in contact with the membrane in the hollow tubular membrane 22 permeates the membrane by its suction force and is collected in the water collection chamber 24. Permeate outlet 27, branch port 30, permeate outlet pipe 1
Water is collected through 8, the communication port 19, and the suction pipe.

On the other hand, the concentrated water that has not permeated the hollow tubular membrane 22 flows out from the upper end of the hollow portion of the hollow tubular membrane 22 into the upper can body 29 on the membrane element 21, and the upper can body 29.
Through the circulation port 17 and the concentrated water introduction port 33 of the water, flows into the water tank 20, is mixed with the raw water in the water tank 20, and is again supplied from the raw water supply port 14 into the raw water supply chamber 10 ′, by the air lift action. And circulates upward in the hollow tubular membrane. Further, the bubbles obtained by upwardly flowing the raw water by the air lift action are discharged from the circulation port 17 of the upper can body 29.

As described above, the membrane element 21 is provided in the outer cylinder 16.
This membrane element 21 has a large number of hollow tubular membranes 22 so that the permeated water collection chamber 24
Since the permeated water that has passed through the membrane and is collected in the permeated water collecting chamber 24 is sampled through the permeated water extraction pipe 18, the opening is formed in the outer cylinder 16. Permeate can be collected without

Further, the hollow tubular membrane 22 can be arranged over almost the entire length of the upward flow of the air lift provided by the air diffusing pipe 12 in the raw water supply chamber 10 ', and the packing density of the membrane element 21 can be increased.

When the inner peripheral surface of the hollow tubular membrane 22 flowing in contact with the raw water becomes dirty and the efficiency of collecting the permeated water decreases, the cleaning liquid is pumped to the permeated water extraction pipe 18 by a pump to collect the permeated water in the membrane element 21. The cleaning liquid supplied to the chamber 24 and attached to the inner peripheral surface of the hollow tubular membrane 22 is removed by a cleaning liquid that permeates the membrane from the outside to the inside. For this, the permeated water in the water collection chamber 24 is sucked and discharged in its entirety, the open / close valve 32 of the exhaust pipe 31 is opened to exhaust the air in the water collection chamber 24, and the raw water supply port 14 and After closing the on-off valve provided at the concentrated water inlet 33 to shut off the water tank 20, the raw water inside the raw water supply chamber 10 'and the outer cylinder 16 is opened at the drain valve (not shown) provided at the raw water supply port 14. Drainage is performed, the on-off valve 32 of the exhaust pipe 31 is closed, and then the cleaning liquid tank and the cleaning liquid supply pipe from the pump are connected to the communication port 19 of the end plate 13 to collect the cleaning liquid in the permeate collection chamber of the membrane element 21. 24, and the cleaning liquid is supplied to the hollow tubular membrane 22.
Permeate from the outer circumference to the inner circumference. The cleaning waste liquid that has permeated the inner periphery of the hollow tubular membrane 22 descends in the hollow tubular membrane 22 along with the removed stains and is discharged to the raw water supply chamber 10 ′. Therefore, the raw water supply port 14 and the discharge valve (not shown). Discharge). When the cleaning is completed, the cleaning liquid remaining in the water collecting chamber 24 of the membrane element 21 is discharged to the outside through the permeated water extraction pipe 18, and the permeated water sampling operation is restarted.

In FIG. 3, two lower can bodies 10 shown in FIGS. 1 and 2 are arranged on the left and right sides, and flanges at opposite ends thereof are joined together by bolts, nuts, etc., so that each lower portion can be integrated. The air diffusers 12 and 12 in the can bodies 10 and 10 and the permeated water extraction pipes 18 and 18 facing each other are brought into contact with each other to communicate with each other, and the end plate 13 is attached to the right end of the lower can body 10 on the right. Indicates the status. Opening 11,1 on the upper surface of each lower can body 10,10
1, outer cylinders 16 and 16 are provided upright, and inside the outer cylinders 16 and 16, upward branch ports 3 provided in permeate extraction pipes 18 and 18 are provided.
The membrane elements 21 and 21 are supported by 0 and 30. Further, two upper can barrels 29, 29 are provided side by side on the upper portions of the outer cylinders 16, 16 and flanges of the opposite end portions thereof are joined together by bolts, nuts and the like. By doing this, raw water is supplied from the raw water supply port 14 to the series of raw water supply chambers 10 ', 10', and pressurized air is supplied from the communication port 15 to the series of diffuser pipes 12, 12 to generate each membrane element 21,
The permeated water that has been membrane-separated from the raw water in 21 can be sucked through the series of permeated water extraction pipes 18, 18 to collect water, and the installation area of the membrane can be easily doubled. Of course, three or four lower can bodies 10 are joined in series to reduce the film installation area to three.
It can be increased to double or quadruple. That is, the high integration of the membrane elements 21 can increase the degree of integration.

In the case of this embodiment, an on-off valve (not shown) is provided between each of the lower can bodies 10 and 10 and the upper can bodies 29, 29 which are connected to each other, and the on-off valves (not shown) are appropriately closed to cut off from other series. As a result, chemical cleaning can be performed without disturbing the operation of other series.

In the embodiment of FIGS. 1 and 2, the membrane element 2
The permeated water that has been membrane-separated from the raw water in 1 is an outlet 27 that projects downward from the lower tube plate 26 of the membrane element 21, and a branch port 3
0, the water was drawn by suction through the permeated water withdrawal pipe 18 provided along the upper circumference in the lower can body 10, but the present invention is not limited to this, and the water is taken out from the upper pipe sheet 25 through the takeout port 27 protruding upward. You can also collect water. In this case, the outlet 27 from the lower tube sheet 26 is closed with a plug and fitted into the upward branch port 30 of the permeated water outlet pipe 18, and thus the membrane element 21 is inserted and supported inside the outer cylinder 16. An L-shaped water sampling pipe penetrating the continuous port 28 of the upper tube body 29 is attached to the outlet 27 projecting from the upper tube plate 26 of the membrane element 21, and the suction pipe from the suction pump is connected to this water sampling pipe. In order to exhaust the air in the water collecting chamber 24 of the membrane element 21 at the time of cleaning, the upper tube plate 25 is provided with a connection port that communicates with the water collecting chamber 24 while avoiding the hollow tubular membrane 22, and the connection port is opened and closed. An exhaust pipe 31 having a valve 32 is connected.

The permeated water sampling operation and washing are the same as those in the above-described embodiment, and the permeated water can be sampled by suctioning from the water sampling pipe.
In addition, the cleaning liquid flows from the water sampling pipe to the water collection chamber 24 of the membrane element 21.
To supply. Also in such an embodiment, a plurality of lower can bodies 10 can be connected in series, and permeated water can be collected from the water collecting pipes that penetrate the individual upper can bodies 29.

On the lower can body 10, as shown in the drawing, an outer cylinder 16 having substantially the same height as the membrane element 21 and a concentrated water circulation port 17 are provided, and are connected to the outer cylinder 16 by flange joining. Although the upper can body 29 is provided, the upper can body 29 is removed to house the membrane element 21 in the outer cylinder 16,
Workability is good because it can be taken out of the outer cylinder 16 for maintenance and inspection or replacement.

[0026]

As described above, according to the present invention, the upper surface of the lower can body which is placed horizontally by connecting the lower can body and the upper can body to the water tank without constructing a treatment tank having a complicated structure. A membrane separation device can be easily assembled by erection of an outer cylinder on the opening of, and inserting and supporting a membrane element having an internal pressure type or external pressure type hollow tubular membrane inside the outer cylinder.

By thus inserting the membrane element into the outer cylinder and accommodating a large number of hollow tubular membranes in the membrane element, the outer cylinder is partitioned into a permeate collection chamber and a raw water flow passage portion,
Since the permeated water that permeates the membrane and collects in the permeated water collection chamber is sampled through the permeated water extraction pipe, the permeated water can be collected without forming an opening in the outer cylinder.

Further, since the hollow tubular membrane can be arranged over almost the entire length of the upward flow of the air lift by the air diffuser, the packing density of the membrane element can be increased.

Further, since the upper can body can be removed and the membrane element can be housed in the outer cylinder, or can be taken out of the outer cylinder for maintenance and inspection or replacement, workability is good.

In order to increase the scale and increase the filling rate of the membrane, it is possible to easily increase the installation area of the membrane to an integral multiple of 2 or more by connecting a plurality of horizontal can bodies in series. is there. In this case, by providing an opening / closing valve between each lower can body and each upper can body that are connected in plurality, chemical cleaning can be performed without disturbing the operation of other series.

[Brief description of drawings]

FIG. 1 is a vertical side view of a first embodiment of a membrane separation device of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a side view when a plurality of horizontal can bodies shown in FIG. 1 are connected in series.

FIG. 4 shows a conventional membrane separation device, (A) is a schematic front view thereof, and (B) is a schematic side view thereof.

[Explanation of symbols]

 10 Lower Can Body 10 'Raw Water Supply Chamber 11 Opening 12 Diffuser Pipe 13 End Plate 14 Raw Water Supply Port 16 Outer Cylinder 17 Circulation Port 18 Permeate Extraction Pipe 19 Communication Port 20 Water Tank 21 Membrane Element 22 Hollow Tubular Membrane 23 Raw Water Flow Channel 24 Permeate collection chamber 25 Upper tube plate 26 Lower tube plate 27 Outlet port 28 Connection port 29 Upper can body 30 Branch port 31 Exhaust pipe 32 Open / close valve 33 Concentrated water inlet port 34 Blind plate

Claims (1)

[Claims] 1. A water tank for storing raw water therein, a horizontal lower can body connected to a lower portion of the water tank to form a raw water supply chamber therein, and having an opening in a part of an upper surface thereof, and the lower can. A large number of hollow tubes are provided inside the body in the longitudinal direction thereof to supply gas into the raw water supply chamber, and an outer cylinder detachably installed to the opening on the upper surface of the lower can body. A tubular membrane is housed, and the inside is separated by a hollow tubular membrane into a permeate collection chamber and a raw water flow channel that is open vertically, and a membrane element that connects the lower end of the raw water flow channel to the raw water supply chamber, It is provided on the upper part of the outer cylinder and is connected to the upper part of the water tank.It consists of a horizontal upper can body that circulates the concentrated water that has passed through the raw water flow passage part from the outer cylinder into the water tank, and supplies it from the water tank to the raw water supply chamber. The raw water flow path of the membrane element with the gas supplied from the diffused raw water The water flows upwards along the hollow tubular membrane, and the water that passes through the raw water flow path and goes up is circulated in the water tank through the upper can body, and the permeated water that permeates the hollow tubular membrane permeates. A membrane separation device using a hollow tubular membrane, wherein water is collected from a water collection chamber to the outside.