JPH10180048A - Immersion type membrane separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the deterioration of the function to separate solid from liquid of hollow tubular membranes by immersing aeration means which are connected to air feed pipes for aeration and eject air bubbles into the water in a treating vessel and enclosing the aeration means by the hollow tubular membranes constituting membrane modules. SOLUTION: Many pieces of the hollow tubular membranes 11 of a water collecting device 12 consisting of the hollow annular bodies of the membrane modules are bent to a U shape by each piece and both ends are plunged and fixed into the hollow water collecting parts 12' of the annular bodies. These membranes exist in the diametral direction of the annular bodies. The aeration means 20 of a resembling shape having the external shape slightly smaller than the internal shape of the cage shapes formed by interlinkage of the U-shaped parts of the many hollow tubular membranes 11 under the annular bodies are concentrically fitted into the cages to prevent the adhesion of SS by uniformly ejecting the air bubbles to all the hollow tubular membranes 11 and applying vibrations thereto. As a result, the long-term and continuous collecting of the permeated liquid P permeating the hollow tubular membranes 11 is made possible and the occurrence of the deterioration in the function to separate solid from the liquid is eliminated. The attachment and detachment of the membranes are facilitated and the washing of the membranes by taking the deteriorated membranes outside the system is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of external pressure type hollow fiber membranes and tubular type membranes such as a reverse osmosis membrane, an ultrafiltration membrane and a microfiltration membrane made of an inorganic material such as alumina ceramic or an organic material. For solid-liquid separation by immersing a hollow tubular membrane module with water into the treatment tank and collecting permeated liquid that has passed through each hollow tubular membrane from the outside to the hollow part due to the head difference and the negative pressure generated by the suction pump. The present invention relates to a submerged membrane separation device.

[0002]

2. Description of the Related Art In such an immersion type membrane separation apparatus, SS adheres to the surface of each hollow tubular membrane in an elongated spaghetti-like manner and grows on the surface of each hollow tubular membrane as the solid-liquid separation is performed. An aeration device is installed below the membrane module in the treatment tank, and the air bubbles floating from the aeration device cause the hollow tubular membrane to float up and down or left and right, vibrate, and remove SS that adheres to and grows on the surface of the hollow tubular membrane. In addition, blocking of the surface of the membrane is prevented. In particular, when solid-liquid separation is performed while biologically treating organic wastewater by allowing aerobic microorganisms to be present in the liquid in the treatment tank, the aerated air activates the aerobic microorganisms, so that the treatment effect is extremely high.

[0003]

However, since air generated by aeration does not uniformly contact one of the hollow tubular membranes constituting the membrane module, the SS partially blocks the surface of the hollow tubular membrane, Due to the stickiness of the SS which adheres to and grows on the surface of the membrane, a blocking phenomenon in which the hollow tubular membrane adheres on the scale of several tens or several hundreds may occur. Furthermore, since the outer diameter of one hollow tubular membrane is 0.2 to 1.0 mm and the embedding density in a water sampling device for forming a membrane module is several tens / cm ² , the floating and vibration caused by aeration may cause 1
When a difference in expansion and contraction occurs in the hollow tubular membrane of the book, the hollow tubular membrane is entangled, and if tension is partially applied, the hollow tubular membrane is cut at that location, and the situation where the solid-liquid separation function is deteriorated sometimes occurs.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been developed to solve the above-mentioned problems, and comprises immersing a membrane module having a large number of external pressure type hollow tubular membranes in water in a treatment tank, In an immersion type membrane separation device for sampling a permeated liquid that has passed through the membrane of each hollow tubular membrane, in the water of the treatment tank, immersing an aeration means connected to an aeration pipe for air supply and ejecting bubbles into the water, The aeration means is surrounded by a hollow tubular membrane constituting the membrane module.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In each of the illustrated embodiments, reference numeral 11 designates an external pressure type hollow tubular membrane, and reference numeral 12 designates a hollow water collecting portion 12 ', and fixes one end of a large number of hollow tubular membranes. Then, as shown in an enlarged manner in FIG. 1 (B), a water sampling device in which the hollow portion of each hollow tubular membrane communicates with the hollow water collecting portion,
2 and a number of hollow tubular membranes 11 fixed at their ends
And the membrane module 10 immersed in the water of the treatment tank 1
Is configured. A water sampling pipe 1 protruding above the water surface of the treatment tank and connected to the suction pump P is provided in the hollow water collecting part of the water sampling apparatus.
3, the liquid in the treatment tank is moved outside the hollow tubular membrane by the reduced pressure suction effect generated in the hollow portion of the hollow tubular membrane for each one through the hollow water collecting section of the water sampling device by the operation of the suction pump. From the water collecting unit 12 ′ of the water sampling device,
Water is sampled via the water sampling pipe 13 and the suction pump P.

An aeration means 20 is immersed in the water of the treatment tank 1 and connected to an aeration pipe 21 for jetting bubbles into the water.
If air bubbles can be blown out uniformly, the wall of the aeration means can be made of non-woven fabric,
It may be made of a porous material or may be made of a metal plate having pores or slits, and the structure is arbitrary.

In the embodiment shown in FIG. 1, a water sampling device 12 for a membrane module is formed of a hollow annular body, and a plurality of hollow tubular membranes 11 are provided.
Is bent in a U-shape, one end of which is fixed by projecting from below into the hollow water collecting portion 12 ′ of the annular body, and is located in the diameter direction of the annular body. As a result, a plurality of hollow tubular membranes having a U-shaped folded portion intersect under the annular body to form a cage shape forming a bottom. A similar aeration means 20 whose outer shape is slightly smaller than the inner shape of the basket is concentrically fitted into the inside of the basket formed by the plurality of hollow tubular membranes, and the plurality of hollow tubular Bubbles are blown out uniformly to all of the film.

The upper surface of the aeration means is closed by an upper wall 20 ',
From the center thereof, a communication pipe 22 having an upper end connected to the air supply pipe 21 stands through the center of the annular body, and the inside of the aeration means communicates with the air supply pipe 21 through the communication pipe 22.

[0009] The annular body of the water sampling device 12 also has a water sampling pipe 1 at the upper end.
3, the annular water collecting portion 12 ′ communicates with the water sampling pipe 13 through the communication pipe 14.

The aeration means 20 descending from the air supply pipe 21 by the communication pipe 22 is concentrically positioned inside a basket composed of a number of hollow tubular membranes, and the aeration means is surrounded by a number of hollow tubular membranes. The annular body of the apparatus is fixed to the water sampling pipe 13 by a plurality of upward mounting members 15.

As described above, the outer shape of the aeration means 20 is slightly smaller than the inner shape of a basket formed by a number of hollow tubular membranes.
Therefore, there is a gap 1 between the hollow tubular membrane and the outer surface of the aeration means.
6 is kept. Therefore, when the suction pump P is operated to perform solid-liquid separation and air is supplied to the air supply pipe 21 from a blower or the like, the aeration means 20 blows air from the entire outer surface except the upper wall 20 'to form a basket. Bubbles are evenly poured and vibrated over the entire length of one of the many hollow tubular membranes. As a result, even if SS tries to adhere to the surface of the hollow tubular membrane, it is removed by vibration and cannot adhere. Thus, the permeated liquid, which can permeate through the hollow tubular membrane, of the liquid in the processing tank by the suction action of the suction pump is transferred to the annular body and the communication pipe 1.
4. Water can be taken continuously for a long time via the water sampling pipe 13. And since SS does not adhere to the surface of the hollow tubular membrane, a blocking phenomenon in which the hollow tubular membranes adhere to each other does not occur, and
Since one hollow tubular membrane vibrates uniformly, cutting by entanglement does not occur.

In the embodiment of FIG. 1, one of a plurality of hollow tubular membranes is used.
The book was bent into a U-shape, and both ends were fixed to an annular body to make the membrane module into a cage shape with a bottom.However, a number of hollow tubular membranes were knitted into a flat mesh shape, and this was deformed into a bag shape. The same operation and effect can be obtained by fixing both ends of one hollow tubular membrane to an annular body by using a membrane module.

In the embodiment shown in FIG. 2, two hollow annular bodies are vertically arranged as a water sampling device 12, and one of a plurality of hollow tubular membranes 11 is connected to an upper end and a lower end of the upper and lower annular bodies. When the membrane module 10 is formed into a cylindrical bottomless cage shape by the upper and lower annular bodies fixed to the upper portion and the upper and lower ends thereof, and a plurality of linear hollow tubular membranes fixed to the upper and lower portions thereof. belongs to. Inside the basket, aeration means 20 of a cylindrical shape whose outer diameter is slightly smaller than the inner diameter surrounded by a number of hollow tubular membranes and whose top and bottom are closed are fitted concentrically, and the outer peripheral surface of the aeration means is Bubbles are blown out uniformly from the whole.

The piping and fixing of the annular body on the membrane module to the water sampling pipe 13 and the piping of the aeration means 20 to the air supply pipe 21 are the same as those in the embodiment of FIG. 1, and the same members are denoted by the same reference numerals. Is omitted. In the embodiment of FIG. 2, since the water sampling device also has an annular body below, a water sampling pipe 13 ′ from the lower annular body is provided, and the lower water sampling pipe 13 ′ and the upper water sampling pipe 13 are connected. Connect to one water suction pump P.

Also in this embodiment, the outer diameter of the cylindrical aeration means 20 is slightly smaller than the inner diameter surrounded by a number of hollow tubular membranes.
Therefore, a gap 16 is maintained between the hollow tubular membrane and the outer peripheral surface of the aeration means. Therefore, when the suction pump P is operated to perform solid-liquid separation and air is supplied to the air supply pipe 21 from a blower or the like, the aeration means 20 ejects air from the entire outer peripheral surface to form a straight line forming a basket. Air bubbles uniformly over the entire length of one of the multiple hollow tubular membranes, and vibrates.
As a result, even if SS tries to adhere to the surface of the hollow tubular membrane, it is removed by vibration and cannot adhere. In this manner, the permeated liquid, which can permeate through the hollow tubular membrane, of the liquid in the processing tank by the suction action of the suction pump is transferred to the upper and lower annular bodies and the communication pipe 1.
4. Water can be continuously taken for a long time via the water sampling pipes 13 and 13 '. Further, since the SS does not adhere to the surface of the hollow tubular membrane, a blocking phenomenon in which the hollow tubular membranes adhere to each other does not occur. In addition, since the hollow tubular membranes of one piece vibrate uniformly, cutting by entanglement does not occur.

In the embodiment shown in FIG. 3, the water sampling device 12 is composed of two left and right horizontal cylinders, and one of a large number of hollow tubular membranes 11 is bent into an arch shape, and the left and right ends thereof are directed downward. Are fixed to the left and right laterally mounted cylinders 12 and 12 from above from above to form a membrane module in a row of tunnels.
And the aeration means 20 enters between the left and right horizontal cylinders,
It is a hollow cylinder having a gap 16 between a plurality of hollow tubular membranes 11 arranged in a row in a tunnel shape, and air bubbles are uniformly ejected from an arch-shaped surface excluding the bottom and both ends. is there.

The left and right 2 which are the water sampling devices 12 of the membrane module
The horizontal cylinder of the book is installed on the bottom surface of the processing tank 1, for example,
The aeration means 20 is installed on the bottom surface of the processing tank so as to be located below a row of tunnels constituted by a large number of hollow tubular membranes between the horizontal cylinders. Then, water sampling pipes 13 and 13 are connected to the end faces of the two horizontal cylinders, respectively, and the two water sampling pipes are connected to one to be connected to a suction pump. An air supply pipe 21 is connected to the end face of the aeration means.

In this state, a gap 16 is maintained between the tunnel formed by the plurality of hollow tubular membranes and the arc-shaped surface of the aeration means. Therefore, when the suction pump P is operated to perform solid-liquid separation and air is supplied to the air supply pipe 21 from a blower or the like, the aeration means 20 blows air from the entire arch-shaped surface to form a tunnel. Bubbles are evenly poured over the entire length of one of the multiple hollow tubular membranes and vibrated. As a result, even if SS tries to adhere to the surface of the hollow tubular membrane, it is removed by vibration and cannot adhere. In this way, the permeated liquid of the liquid in the processing tank, which has been able to permeate through the hollow tubular membrane by the suction action of the suction pump, can be continuously sampled for a long time through the horizontal cylinder and the water sampling pipes 13, 13. Further, since SS does not adhere to the surface of the hollow tubular membrane, a blocking phenomenon in which the hollow tubular membranes adhere to each other does not occur, and 1
Since the hollow tubular membrane destined for the book vibrates uniformly, no cut due to entanglement occurs.

In the embodiment shown in FIGS. 1 and 2, the membrane module and the aeration means are installed vertically in the processing tank. In the embodiment shown in FIG. 3, the membrane module and the aeration means are installed horizontally in the processing tank. The installation direction or direction is not limited to the above, and is arbitrary.

[0020]

As is apparent from the above description, according to the present invention, air bubbles are evenly applied to the entire length of one of the plurality of hollow tubular membranes constituting the membrane module and vibrated to form the hollow tubular membrane. The SS that is to adhere to the surface of the film is wiped off by vibration to prevent the adhesion. Therefore, the permeated liquid of the liquid in the treatment tank, which can permeate through the hollow tubular membrane, can be continuously sampled for a long time by the suction action of the suction pump. Since the SS does not adhere to the surface of the hollow tubular membrane, a blocking phenomenon in which the hollow tubular membranes adhere to each other does not occur, and the hollow tubular membrane of one piece vibrates uniformly. No cutting due to the entanglement that occurs. Further, since the desorption is easy, it is easy to replace the membrane or to take out the deteriorated membrane out of the system and to clean it.

[Brief description of the drawings]

FIG. 1A is an exploded perspective view of a membrane module according to a first embodiment of the present invention and aeration means, and FIG. 1B is a cross-sectional view of the membrane module and an immersion type membrane separation device constituted by the aeration means. is there.

FIG. 2 (A) is an exploded perspective view of a membrane module according to a second embodiment of the present invention and aeration means, and FIG. 2 (B) is a cross-sectional view of the membrane module and an immersion type membrane separation device constituted by the aeration means. is there.

FIG. 3A is a perspective view of a membrane module according to a third embodiment of the present invention and aeration means, and FIG.
It is sectional drawing of the immersion type | mold membrane separation apparatus comprised by the aeration means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing tank 10 Membrane module 11 Hollow tubular membrane of membrane module 12 Sampling device of membrane module 13 Sampling pipe 20 Aeration means 21 Aeration pipe to aeration means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C02F 3/12 C02F 3/12 S

Claims (1)

[Claims] 1. A immersion type membrane separation apparatus for immersing a membrane module having a large number of external pressure type hollow tubular membranes in water of a treatment tank and collecting a permeate having passed through the membranes of the hollow tubular membranes. An immersion type membrane, characterized by immersing aeration means for discharging air bubbles into water by connecting to an air supply pipe for aeration in water of a treatment tank, and surrounding the aeration means by a hollow tubular membrane constituting the membrane module. Separation device.