JP2010104932A - Air diffuser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control the blockage of air diffusion holes due to sludge in relation to an air diffuser. <P>SOLUTION: In the air diffuser, diffused air holes (6a) are arranged alternatively to the cross line (X1) of an aeration tube (6) and a vertical plane passing through the cross-section central line (X0) of the aeration tube (6). Since aeration holes (6a) are present on either side of the aeration tube (6), air bubbles dispersed on both sides of the aeration tube (6) uprear, thus preventing deviation of aeration. Though airborne droplets of raw water intruding from the aeration holes (6a) slide down on the inner wall of the aeration tube (6) and stop at the lowest part of the aeration tube (6), sludge in raw water hardly blocks the aeration holes (6a) since the aeration holes (6a) are not situated at the lowest part of the aeration tube (6). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an air diffuser, and more particularly to an air diffuser capable of suppressing the obstruction of air diffuser holes by sludge with a simple configuration that is easy to implement.

2. Description of the Related Art Conventionally, there is known an air diffuser in which a plurality of air diffuser holes with a diameter of 5 to 10 mm are provided in a diffuser pipe at a pitch of 100 to 200 mm, and an air diffuser speed from the air diffuser holes is 10 [m / sec] or more ( For example, see Patent Document 1.)
JP-A-11-28463 ([0006])

The conventional diffuser has a problem that raw water enters the diffuser pipe through the diffuser hole, and sludge in the raw water dries in the diffuser pipe to block the diffuser hole.
On the other hand, it has been proposed to attach an ejection pipe having a length of 10 [mm] or more to each diffuser hole, but there is a problem that the configuration becomes complicated and difficult to implement.
Therefore, an object of the present invention is to provide an air diffuser that can suppress the obstruction of the air diffuser hole by sludge with a simple configuration that is easy to implement.

In the first aspect, the present invention provides a filter element (2) for filtering raw water (S), a diffuser pipe (6) for releasing bubbles in the raw water (S), and a diffuser of the diffuser pipe (6). In the air diffuser comprising an air supply means (50) for supplying air diffused from the air holes (6a), a vertical plane passing through the cross-sectional center line (X0) of the air diffuser pipe (6) and the air diffuser pipe ( The air diffuser is characterized in that the air diffuser holes (6a) are arranged in a staggered manner with respect to the cross line (X1) of 6).
In the air diffuser according to the first aspect, by arranging the air diffuser holes (6a) in a staggered manner, the air diffuser holes (6a) exist on the left and right of the air diffuser pipe (6) even if the construction accuracy is somewhat poor. Therefore, the bubbles are dispersed on both sides of the air diffuser (6) and the air bubbles can be prevented from being displaced. Further, by arranging the diffuser holes (6a) in a staggered manner, when sludge enters the diffuser pipe (6) and the sludge slides down the inner wall of the diffuser pipe (6), the other diffuser holes (6a) are blocked. There is no effect.

In a second aspect, the present invention provides a filter element (2) for filtering raw water (S), a diffuser pipe (6) for releasing bubbles in the raw water (S), and a diffuser of the diffuser pipe (6). In the air diffuser comprising an air supply means (50) for supplying air diffused from the air holes (6a), the air diffuser is orthogonal to the cross-sectional center line (X0) of the air diffuser pipe (6) and An angle θ formed by a vertical line (Y) dropped from the cross-sectional center line (X0) on a plane passing through 6a) and a straight line (L) connecting the cross-sectional center line (X0) and the diffuser hole (6a) is An air diffuser is provided that is within an angle range of 10 degrees to 40 degrees.
In the air diffusing device according to the second aspect, the splash of the raw water S that has entered from the air diffusing holes 6a as shown in FIG. 4 (a) causes the inner wall of the air diffusing pipe 6 as shown in FIG. 4 (b). As shown in FIG. 4 (c), it slides down and stops at the lowermost part of the air diffuser 6. However, since the air diffuser 6a is not located at the lowermost part of the air diffuser 6, sludge in the raw water S is diffused. It becomes difficult to block 6a. That is, blockage of the air diffusion hole 6a due to sludge can be suppressed with a simple configuration that is easy to implement (an ejection pipe is unnecessary).
On the other hand, in the conventional air diffuser, since the air diffuser hole 6a ′ is at the lowermost part of the air diffuser tube 6 ′ as shown in FIG. 7, the air diffuser hole 6a ′ as shown in FIG. Since the splash of the raw water S that has entered from the inside slides down the inner wall of the air diffusing pipe 6 ′ as shown in FIG. 7B, and stops on the air diffusing hole 6a ′ as shown in FIG. Sludge in the raw water S is likely to block the aeration holes 6a ′.

In a third aspect, the present invention provides the air diffuser according to the first or second aspect, wherein the air diffusion speed from the air diffusion hole (6a) is 17.5 [m per hole in terms of atmospheric pressure. / Sec] and 25 [m / sec] or less.
In the air diffuser according to the third aspect, as shown in FIG. 5, the amount of water infiltrated from the air diffuser hole (6a) into the air diffuser pipe (6) can be remarkably suppressed. Blockage can be suppressed.

In a fourth aspect, the present invention provides the air diffuser according to any one of the first to third aspects, wherein the end of the air diffuser pipe (6) opposite to the air supply side to the air diffuser pipe (6) is provided. An air diffuser characterized in that the portion is bent downward and the end face is an opening (6b) is provided.
In the air diffuser according to the fourth aspect, the sludge accumulated in the air diffuser (6) can be discharged from the opening (6b) of the air diffuser (6) as shown in FIG.

In a fifth aspect, the present invention provides an air diffuser characterized in that, in the air diffuser according to the fourth aspect, a plurality of the air diffusers (6) are installed so that the installation interval and the number of installation can be changed. provide.
In the air diffuser according to the fifth aspect, according to the local situation, the interval between the air diffusers and the number of the air diffusers can be easily installed so that the cake does not easily adhere between the filter elements and the air can be evenly diffused. Can be optimized.

  According to the air diffusing device of the present invention, it is possible to suppress the blockage of the air diffusing holes due to sludge with a simple configuration that is easy to implement.

  Hereinafter, the present invention will be described in more detail with reference to embodiments shown in the drawings. Note that the present invention is not limited thereby.

FIG. 1 is a perspective view of a membrane filtration device 1 including an air diffuser according to a first embodiment.
The membrane filtration device 1 includes, for example, 100 immersion membranes 2, a water collection pipe 3 for collecting filtrate water from each immersion membrane 2, a filtrate water outlet of each immersion membrane 2, and a filtrate water inlet of the water collection pipe 3. Are connected to each other, a filtered water pipe 4 for collecting the filtered water D in the water collecting pipe 3, a diffuser pipe 6 installed horizontally below the immersion membrane 2, and a bent pipe 7 for changing the direction by 90 °, A y-tube having an air pipe 9a and a bit port 9b, which is connected to the diffuser pipe 6 by a bent pipe 7 and rises in the vertical direction to go out of the raw water S and send air from the raw water S to the diffuser pipe 6. 9 and a blower 50 for feeding air into the air pipe 8.
The diffuser tube 6 is provided with a plurality of diffuser holes 6a. Further, the end of the air diffusing tube 6 on the side opposite to the bent tube 7 is bent downward and the end surface is an opening 6b.
The immersion film 2 and the like are immersed in the raw water S.

FIG. 2 is a bottom view of the air diffuser 6. 3 is a cross-sectional view taken along the line AA ′ of FIG.
An angle θ formed by a vertical line Y perpendicular to the cross-sectional center line X0 of the air diffuser 6 and passing through the air diffuser hole 6a and a straight line L connecting the cross-sectional center line X0 and the air diffuser hole 6a. Is within an angular range of 10 to 40 degrees.
The diffuser holes 6 a are arranged in a staggered manner with respect to a vertical plane passing through the cross-sectional center line X0 of the diffuser tube 6 and the intersection line X1 of the diffuser tube 6.

  As a specific example, the air diffusing tube 6 is a PP tube having an inner diameter of 40 mm. The diameter of the air holes 6a is 4 mm, the pitch is 30 mm, the number of air holes 6a is 90, and θ = 10 degrees.

  As shown to (a) of FIG. 4, the splash of the raw | natural water S penetrate | invades from the diffuser hole 6a during a driving | operation. This splash slides down the inner wall of the air diffuser 6 as shown in FIG. 4B, and stops at the lowermost part of the air diffuser 6 as shown in FIG. And although it dries and sludge remains, since the diffuser hole 6a is not located in the lowest part of the diffuser tube 6, the diffuser hole 6a is hard to block | close.

FIG. 5 is a graph showing the amount of water infiltrated from the air diffuser hole 6a into the air diffuser pipe 6 with respect to the air diffused velocity from the air diffuser hole 6a.
Although it is preferable to set it to 10 [m / sec] or more for sufficient air diffusion, the amount of water immersion is large up to 17.5 [m / sec]. That is, the amount of sludge that enters the diffuser 6 is large. Therefore, it should be 17.5 [m / sec] or more.
On the other hand, even if it is larger than 25 [m / sec], the amount of water immersion does not change, and the burden on the blower 50 increases for that.
Therefore, it should be 17.5 [m / sec] or more and 25 [m / sec] or less.

  According to the air diffuser according to the first embodiment, it is possible to suppress the blockage of the air diffuser hole 6a due to sludge, and it is not necessary to attach an ejection pipe to each air diffuser hole 6a, and the simple configuration is easy to implement. Become.

Still, when the operation time becomes long, a large amount of sludge accumulates in the air diffuser 6.
In that case, for example, as shown in FIG. 6, the bit 10 attached to the tip of the flexible shaft 20 is inserted from the bit port 9 b, inserted through the y-shaped tube 9, the air supply tube 8, and the bent tube 7 to the diffuser tube 6. . Then, the electric drill 30 rotates the bit 10 through the flexible shaft 20 and causes the bit 10 to perform a pendulum motion, and the sludge M is discharged from the end surface opening 6 b of the air diffusion pipe 6 while scraping off the sludge in the air diffusion pipe 6. . This operation may be a cleaning method using pressure water.

  The air diffuser of the present invention can be used in water treatment facilities such as water purification, drainage and wastewater treatment facilities.

1 is a perspective view showing a membrane filtration device including an air diffuser according to Example 1. FIG. It is a bottom view of the air diffusing tube according to the first embodiment. It is A-A 'sectional drawing of FIG. It is sectional drawing which shows a motion of the raw | natural water splash in the diffuser tube which concerns on Example 1. FIG. It is a graph which shows the amount of water infiltrated into the diffuser pipe from the diffuser hole with respect to the air diffused velocity from the diffuser hole. It is sectional drawing which shows the cleaning state of the diffuser tube which concerns on Example 1. FIG. It is sectional drawing which shows the motion of the raw | natural water splash in the conventional diffuser.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Membrane filtration apparatus 2 Immersion membrane 3 Water collecting pipe 4 Filtration water pipe 5 Pump 6 Aeration pipe 7 Bending pipe 8 Air supply pipe 9 Y-shaped pipe 50 Blower D Filtration water M Sludge S Raw water

Claims (5)

Filter element (2) for filtering raw water (S), diffuser pipe (6) for releasing bubbles in raw water (S), and air diffused from diffuser hole (6a) of said diffuser pipe (6) In the air diffuser comprising an air supply means (50) for supplying air, with respect to a vertical plane passing through the cross-sectional center line (X0) of the air diffuser pipe (6) and an intersection line (X1) of the air diffuser pipe (6) The air diffusing hole (6a) is arranged in a staggered manner. Filter element (2) for filtering raw water (S), diffuser pipe (6) for releasing bubbles in raw water (S), and air diffused from diffuser hole (6a) of said diffuser pipe (6) An air supply means (50) for supplying air, wherein the cross-sectional center on a plane orthogonal to the cross-sectional center line (X0) of the air diffusing pipe (6) and passing through the air diffusing hole (6a) The angle θ formed by the vertical line (Y) drawn from the line (X0), the cross-sectional center line (X0), and the straight line (L) connecting the diffuser holes (6a) is within an angle range of 10 degrees to 40 degrees. A diffuser characterized by being. The air diffuser according to claim 1 or 2, wherein an air diffused velocity from the air diffuser hole (6a) is 17.5 [m / sec] or more per hole and 25 [m / sec. sec] A diffuser characterized by: The air diffuser according to any one of claims 1 to 3, wherein an end of the air diffuser pipe (6) opposite to an air supply side to the air diffuser pipe (6) is bent downward and an end face is opened. An air diffuser characterized in that it is (6b). The air diffusing device according to claim 4, wherein a plurality of the air diffusing pipes (6) are installed so that an installation interval and the number of installation can be changed.

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