JP2016168546A - Membrane separator, membrane element and dreg contact inhibition member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a membrane separator capable of preventing a separation membrane from damage caused by the contact of attached dregs to the separation membrane.SOLUTION: In a membrane separator 1 where a plurality of membrane elements 4 with separation membranes 10 on filter plates 9 are housed in a case 3 and arranged with a predetermined interval in a state of facing membrane surfaces each other,: the separation membrane 10 is joined to the filter plate 9 along a peripheral edge part; a dreg contact inhibition portion 27 is equipped below a junction 19a between the lower part of the separation membrane 10 and the filter plate 9; and the dreg contact inhibition portion 27 inhibits dregs 26 captured by the dreg contact inhibition portion 27 from contacting to the upper part of the separation membrane 10 from the junction 19a.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a membrane separation device, a membrane element, and a residue contact suppressing member used for membrane separation activated sludge treatment.

  Conventionally, as this type of membrane separation device, as shown in FIG. 11, there is a device in which a plurality of flat membrane modules 101 are provided in a container, and an aeration device is installed below the flat membrane module 101. The flat membrane module 101 includes a flat spacer 102 and membranes 103 attached to both sides of the spacer 102. Among these flat membrane modules 101, the heights of the flat membrane modules 101 adjacent to each other are provided with a height difference 104, and the positions of the lower end portions thereof are alternately varied.

  According to this, by releasing bubbles from the aeration apparatus, an upward flow 105 that flows upward from below the flat membrane module 101 is generated. When the filtration is continued in this state, the residue 106 such as hair or paper fragments mixed in the stock solution is gradually entangled with the lower end portion of the flat membrane module 101.

  On the other hand, since the height difference 104 is given to the mounting height of the flat membrane modules 101 adjacent to each other, the interval between the lower end portions of the flat membrane module 101 functioning as the inlet of the stock solution passage 107 is adhered. It is possible to prevent clogging by the residue 106.

  The above membrane separation apparatus is described in, for example, Patent Document 1 below.

JP-A-6-198144

  However, in the above conventional format, as shown in FIG. 12, when the residue 106 attached to the lower end of the flat membrane module 101 grows gradually and the flat membrane module 101 vibrates in the direction indicated by the arrow during aeration, The grown residue 106 comes into contact with the film 103 of the adjacent flat membrane module 101, and the residue 106 and the film 103 are rubbed against each other to damage the film 103.

  An object of the present invention is to provide a membrane separation device, a membrane element, and a residue contact suppressing member that can prevent adhesion and growth of residue and contact with the separation membrane to damage the separation membrane. .

In order to achieve the above object, according to the first aspect of the present invention, a plurality of membrane elements each provided with a separation membrane on a filter plate are accommodated in a case and arranged at a predetermined interval with the membrane surfaces facing each other. A membrane separation device,
The separation membrane is joined to the filter plate along the peripheral edge,
Below the junction between the lower part of the separation membrane and the filter plate, a residue contact suppression part is provided,
The residue contact suppression unit suppresses the residue in the liquid to be treated captured by the residue contact suppression unit from coming into contact with the separation membrane above the joint.

  According to this, an upward flow that flows upward from below the membrane element is generated, and when the filtration operation is performed in this state, the residue in the liquid to be treated is captured from the bottom of the membrane element by the residue contact suppression unit. Even if it is done, it is possible to prevent the trapped residue from growing on the separation membrane in the region (effective filtration region) above the junction between the lower part of the separation membrane and the filter plate. Thereby, it is possible to prevent the residue and the separation membrane from rubbing in a region above the joint portion, and it is possible to prevent damage to the separation membrane.

In the membrane separation device according to the second aspect of the present invention, one support portion that supports one side portion in the width direction of the membrane element from below is provided in the case, and the other support portion that supports the other side portion from below. ,
An opening is formed between one support and the other support,
The residue contact suppressing portion is formed over the entire width of the opening.

  According to this, the upward flow flows upward from the lower side of the membrane element through the opening. At this time, even if the residue in the liquid to be treated that passes through the opening is captured by the residue contact suppressing portion, the separation membrane in the region above the junction between the lower portion of the separation membrane and the filter plate It can be prevented that it adheres to and grows.

In the membrane separation apparatus according to the third aspect of the invention, the residue contact suppressing portion is formed integrally with the filter plate of the membrane element.
In the membrane separation apparatus according to the fourth aspect of the present invention, the residue contact suppressing portion is formed separately from the membrane element.

The fifth aspect of the present invention is a membrane element provided with a separation membrane on a filter plate and used for membrane separation activated sludge treatment,
The separation membrane is joined to the filter plate along the peripheral edge,
In the lower region of 30 mm or more from the junction between the lower part of the separation membrane and the filter plate, a residue contact suppressing part is provided,
The residue contact suppression unit suppresses the residue in the liquid to be treated captured by the residue contact suppression unit from coming into contact with the separation membrane above the joint.

  According to this, an upward flow that flows upward from below the membrane element is generated, and when the filtration operation is performed in this state, the residue in the liquid to be treated is captured from the lower part of the membrane element to the residue contact suppression part. Is done. Here, since the residue contact suppression part is provided in a lower region of 30 mm or more from the junction between the lower part of the separation membrane and the filter plate, the distance from the lower end of the residue contact suppression part to the junction is at least 30 mm. A large amount of residue remaining in the liquid to be processed without being removed by a screen or the like provided before the membrane element is within the region from the lower end of the contact prevention unit to the joint (effective Captured in the area outside the filtration area).

In the membrane element according to the sixth aspect of the present invention, the residue contact suppression portion is provided in a lower region of 30 mm or more from the lower end portion of the separation membrane.
According to this, since the residue contact suppression part is provided in the lower region of 30 mm or more from the lower side edge of the separation membrane, the distance from the lower end of the residue contact inhibition part to the lower edge of the separation membrane is secured 30 mm or more. A large amount of residue remaining in the liquid to be treated without being removed by a screen or the like provided in front of the membrane element is within the region from the lower end of the residue contact suppressing portion to the lower end portion of the separation membrane. Be captured.

  In the membrane element according to the seventh aspect of the present invention, the residue contact suppressing portion has a pair of vertical front and rear surfaces facing each other in the thickness direction and a horizontal lower end surface formed between the lower ends of the front and rear surfaces.

  According to this, since the residue contact suppressing portion has a horizontal lower end surface, the residue in the liquid to be treated is easily entangled from the lower side of the residue contact suppressing portion from below the membrane element, and reliably the residue contact suppressing portion. Captured.

The residue contact suppressing member in the eighth invention is used in the membrane separation activated sludge treatment, and is disposed on the lower side of the membrane element in which the separation membrane is joined to the filter plate.
It prevents the residue in the liquid to be treated captured below the separation membrane from coming into contact with the separation membrane.

  As described above, according to the present invention, it is possible to prevent the grown residue from coming into contact with the separation membrane of the membrane element and damaging the separation membrane.

1 is a partially cutaway perspective view of a membrane separation apparatus according to a first embodiment of the present invention. FIG. 2 is a front view of a single membrane element provided in the membrane separation device. FIG. 3 is a side view of a plurality of arranged membrane elements provided in the membrane separation device. It is a front view of the membrane element accommodated in the case of the membrane separator. FIG. 3 is a side view of a plurality of membrane elements housed and arranged in the case of the membrane separation device. It is a lower part front view of the conventional membrane element given as a reference. It is a lower part front view of the membrane element in the 3rd Embodiment of this invention. It is a front view of the membrane element accommodated in the case of the membrane separator in the 4th Embodiment of this invention. It is a front view of the same membrane element. It is a front view of the membrane element accommodated in the case of the membrane separator in the 5th Embodiment of this invention. It is a side view of the conventional some arranged flat membrane module. It is a side view of a plurality of arranged flat membrane modules.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
In the first embodiment, as shown in FIG. 1, reference numeral 1 denotes a membrane separation device used for membrane separation activated sludge treatment, and this membrane separation device 1 is installed by being immersed in a treatment tank (not shown). ing. The membrane separation device 1 includes a case 3, a plurality of plate-like membrane elements 4 accommodated in the case 3, and an air diffuser 5 installed below the membrane element 4.

  The case 3 is open at both upper and lower ends, and is divided into an upper film case 7 and a lower air diffusion case 8. The membrane case 7 is configured so that the membrane element 4 can be taken in and out of the membrane case 7 upward. The diffuser 5 is installed in the diffuser case 8.

  As shown in FIGS. 2 and 3, the membrane element 4 has a square plate-like filter plate 9 made of resin and separation membranes 10 provided on both sides of the filter plate 9, and the membrane surfaces are opposed to each other. In this state, they are arranged at a predetermined interval A. The separation membrane 10 is joined to the filter plate 9 along the peripheral edge by ultrasonic welding, thermal welding, laser welding, or the like. As a result, a rectangular frame-shaped joint portion 19 (welded portion) is formed inside the peripheral edge portion of the separation membrane 10. In addition, the area | region enclosed by the junction part 19 is the effective filtration area | region 33, In this effective filtration area | region 33, the to-be-processed liquid 25 permeate | transmits the separation membrane 10, and the permeated liquid 11 is obtained.

  A permeate channel (not shown) through which the permeate 11 flows is formed between the filter plate 9 and the separation membrane 10 and inside the filter plate 9, and a permeate outlet 12 communicating with the permeate channel is connected to the filter plate 9. It is provided at the upper end of the plate 9. The permeate outlet 12 is connected to a permeate outlet 29, and the permeate outlet 29 is provided with a suction pump (not shown) for sucking the permeate 11.

  As shown in FIG. 4, in the case 3, one support portion 14 a that supports one side portion of the membrane element 4 in the width direction W from below, and the other support portion 14 b that supports the other side portion from below. One presser portion 15a that prevents the lifting of one side portion and the other presser portion 15b that prevents the other side portion from lifting are provided.

  As shown in FIG. 5, both support portions 14 a and 14 b are comb-like members having a plurality of uneven portions 17 and 18, and similarly, both presser portions 15 a and 15 b have a plurality of uneven portions 20 and 21. It is a comb-like member. Each membrane element 4 is inserted and held in the recesses 17 and 20. As shown in FIG. 4, an opening 22 (see FIG. 8) is formed between one support portion 14a and the other support portion 14b. The inside of the membrane case 7 and the inside of the diffuser case 8 communicate with each other in the vertical direction via the opening 22.

  In a lower region 24 of 40 mm from the joint portion 19a (hereinafter referred to as the lower joint portion 19a) between the lower part of the separation membrane 10 and the filter plate 9, a residue contact suppression portion that captures the residue 26 in the liquid 25 to be treated. 27 is provided.

  The residue contact suppressing portion 27 is integral with the filter plate 9 and is formed over the entire width of the opening 22 as shown in FIG. 4, and can be inserted into the opening 22 from above, and has a thickness as shown in FIG. It has a pair of vertical front and rear surfaces 27a and 27b opposed in the direction T, and a horizontal lower surface 27c formed between the lower ends of the front and rear surfaces 27a and 27b. In addition, as shown in FIG. 4, the width dimension B of the residue contact suppressing portion 27 is as shown in FIG. 2 because both sides of the membrane element 4 are supported by the two support portions 14a and 14b from below. It becomes smaller than the width dimension C of the filter plate 9.

Hereinafter, the operation of the above configuration will be described.
During the filtering operation, the upward flow 32 flowing from the bottom to the top is generated in the case 3 by ejecting bubbles from the air diffuser 5. As shown in FIG. 4, the upward flow 32 flows between the membrane elements 4 from the diffuser case 8 through the opening 22. At this time, by operating the suction pump to apply a suction pressure (negative pressure) to the secondary side of the separation membrane 10, a part of the upward flow 32 permeates the separation membrane 10 and becomes the permeate 11. It is taken out from the permeate outlet 12 through the permeate outlet line 29.

  During such a filtration operation, as shown by the phantom lines in FIGS. 3 and 4, the residue 26 such as hair or paper fragments contained in the liquid to be treated 25 flowing through the opening 22 is formed on the membrane element 4. From below, it may adhere to and be captured by the residue contact suppression unit 27. Here, as shown in FIG. 2, the distance D from the lower end of the residue contact suppressing portion 27 to the lower joint portion 19a is secured to 40 mm, and most of the residue 26 captured by the residue contact suppressing portion 27 is It is captured in the region 24 from the lower end of the residue contact suppressing portion 27 to the lower joint portion 19a. As a result, the residue 26 and the separation membrane 10 can be prevented from rubbing in the effective filtration region 33 above the lower joint portion 19a, and damage to the separation membrane 10 in the effective filtration region 33 can be prevented. it can.

  Further, as shown in FIG. 3, the screen residue contact suppressing portion 27 has a horizontal lower end surface 27 c, so that the screen residue 26 in the liquid to be treated 25 extends from below the membrane element 4 and the bottom end surface of the screen residue contact suppressing portion 27. When entangled with 27c, the length of contact of the screen residue 26 with the front surface 27a or the rear surface 27b of the screen residue contact suppression unit 27 is shortened by the amount of the lower end surface 27c, and the function of the screen contact suppression unit 27 can be exhibited more Therefore, it is preferable.

  As shown in FIG. 2, the residue 26 adheres to a portion 10 a that protrudes downward from the lower joint portion 19 a of the separation membrane 10 (hereinafter, referred to as a downward protrusion portion 10 a), and the residue 26 and the separation membrane 10. Even if the lower protruding portion 10a rubs against each other and the lower protruding portion 10a of the separation membrane 10 is damaged, the lower protruding portion 10a is outside the effective filtration region 33, so that the liquid to be treated is not filtered. 25 does not enter the permeate 11 on the secondary side of the separation membrane 10 and does not adversely affect the cleanliness of the permeate 11. For this reason, it may be acceptable to allow the residue 26 to adhere to the protruding portion 10a below the separation membrane 10.

  For reference, Table 1 below shows the results of investigating the damage position of the separation membrane of the conventional membrane element. As shown in FIG. 6, the conventional membrane element 60 is not provided with the residue contact suppressing portion 27 as described in the first embodiment, and the lower joint portion 19 a from the lower end of the filter plate 9. The distance K1 from the lower end of the filter plate 9 to the lower end of the separation membrane 10 is set to 10 mm. Table 1 below shows that 400 separation membranes 10 are obtained by examining 400 conventional membrane elements 60 in a water treatment facility that has a large influence of the residue even if the residue is removed with a screen or the like before the membrane separation apparatus. The number of sheets damaged by the residue 26 is shown.

これによると、分離膜１０が損傷した計１０枚の膜エレメント６０のうち、９枚（すなわち９０％）については、分離膜１０の損傷位置が濾板９の下端から上方へ３０ｍｍの領域Ｋ３内に存在している。

According to this, out of a total of 10 membrane elements 60 in which the separation membrane 10 is damaged, about 9 (ie, 90%), the damage position of the separation membrane 10 is within the region K3 30 mm upward from the lower end of the filter plate 9. Exists.

  Based on the results of such investigation, in the first embodiment, as shown in FIG. 2, the residue contact suppression portion 27 is formed in the lower region 24 40 mm from the lower joint portion 19a, thereby removing the residue. It is possible to prevent most of the residue 26 captured by the contact suppression unit 27 from adhering to the effective filtration region 33 of the separation membrane 10.

  If the residue 26 adheres to the effective filtration region 33 of the separation membrane 10, the residue 26 is adsorbed on the primary side surface of the separation membrane 10 by the suction pressure, so that the growth of the residue 26 is accelerated. The residue 26 becomes large in a short period and the separation membrane 10 is easily damaged.

  In the first embodiment, the screen residue contact suppressing portion 27 is provided over the lower region 24 40 mm from the lower joint portion 19a. However, the present invention is not limited to 40 mm, and the screen residue contact suppressing portion is formed from the lower joint portion 19a. What is necessary is just to ensure the distance D to the lower end of 27 30 mm or more (namely, at least 30 mm).

(Second Embodiment)
In the first embodiment, as shown in FIG. 2, the residue contact suppression portion 27 is provided in the lower region 24 40 mm from the lower joint portion 19a. However, in the second embodiment, the residue contact suppression portion 27 is provided in the lower region 24 of 30 mm or more from the lower edge portion 10 b of the separation membrane 10.

  According to this, since the distance from the lower edge part 10b of the separation membrane 10 to the lower end of the residue contact suppression unit 27 is secured at least 30 mm, most of the residue 26 is separated from the lower end of the residue contact suppression unit 27 from the separation membrane 10. Is captured in the region up to the lower edge 10b. Thereby, it is possible to prevent the residue 26 from adhering not only to the effective filtration region 33 of the separation membrane 10 but also to the downward protruding portion 10a.

(Third embodiment)
In the first embodiment, as shown in FIG. 2, the residue contact suppression portion 27 is formed integrally with the filter plate 9, but in the third embodiment, as shown in FIG. The residue contact suppressing member 40 (corresponding to the residue contact suppressing portion) may be manufactured as an attachment separately from the filter plate 9 and attached to the lower end portion of the filter plate 9 using a fastener such as a screw 41. Good.

(Fourth embodiment)
In the first embodiment, as shown in FIG. 4, the screen residue contact suppressing portion 27 is inserted into the opening 22 in a state where the membrane element 4 is accommodated in the case 3. In this embodiment, as shown in FIGS. 8 and 9, the bottom contact area 27 is not inserted into the opening 22 and the lower region 24 from the lower joint 19 a of the separation membrane 10 to the lower end of the filter plate 9 is 30 mm. As described above, the lower region 24 may be used as the residue contact suppression unit 27.

(Fifth embodiment)
In the first embodiment, as shown in FIG. 2, the residue contact suppressing portion 27 is formed integrally with the filter plate 9, but may be formed separately. For example, in the fifth embodiment, as shown in FIG. 10, the residue contact suppressing portion 27 may be provided between the both side plate portions 45 of the case 3 and disposed immediately below the filter plate 9.

DESCRIPTION OF SYMBOLS 1 Membrane separation apparatus 3 Case 4 Membrane element 9 Filter plate 10 Separation membranes 14a and 14b Support portion 19a Lower joint portion 22 Opening portion 24 Lower region 25 Liquid to be treated 26 Sediment 27 Screen residue contact suppressing portion 27a Front surface 27b Rear surface 27c Lower end surface 40 Residue contact suppression member A Predetermined interval T Thickness direction W Width direction

Claims (8)

A plurality of membrane elements each provided with a separation membrane on a filter plate are housed in a case, and are membrane separation devices arranged with a predetermined interval in a state where membrane surfaces face each other,
The separation membrane is joined to the filter plate along the peripheral edge,
Below the junction between the lower part of the separation membrane and the filter plate, a residue contact suppression part is provided,
The scum contact suppressor is a membrane separation apparatus that suppresses the scum in the liquid to be treated captured by the scum contact suppressor from coming into contact with the separation membrane above the joint. In the case, one support part that supports one side part in the width direction of the membrane element from below and the other support part that supports the other side part from below are provided,
An opening is formed between one support and the other support,
2. The membrane separation device according to claim 1, wherein the residue contact suppressing portion is formed over the entire width of the opening. The membrane separation apparatus according to claim 1 or 2, wherein the residue contact suppressing portion is formed integrally with the filter plate of the membrane element. The membrane separation apparatus according to claim 1 or 2, wherein the residue contact suppressing portion is formed separately from the membrane element. A membrane element provided with a separation membrane on a filter plate and used for membrane separation activated sludge treatment,
The separation membrane is joined to the filter plate along the peripheral edge,
In the lower region of 30 mm or more from the junction between the lower part of the separation membrane and the filter plate, a residue contact suppressing part is provided,
The scum contact suppressor is a membrane element that suppresses the scum in the liquid to be treated captured by the scum contact suppressor from coming into contact with the separation membrane above the joint. 6. The membrane element according to claim 5, wherein the residue contact suppressing portion is provided in a lower region of 30 mm or more from the lower end portion of the separation membrane. The residue contact suppressing portion has a pair of vertical front and rear surfaces facing each other in the thickness direction, and a horizontal lower end surface formed between the lower ends of the front and rear surfaces. The membrane element as described. Used in membrane separation activated sludge treatment, disposed on the lower side of the membrane element where the separation membrane is joined to the filter plate,
A scum contact suppressing member, characterized in that the scum in the liquid to be treated trapped below the separation membrane is prevented from coming into contact with the separation membrane.

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