JP2003024974A - Air diffusing device and aeration tank using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air diffusing device capable of enhancing an effective bubbling area/arranging area ratio and reducing the resistance of water streams, and an aeration tank using the same. SOLUTION: A pipe 10 having a semicircular or square cross section is used as a holder also used as a venting pipe and a plurality of air diffusion plates 11 are mounted on the planar part of the pipe 10. It is preferable to allow the width of each of the air diffusion plates 11 to coincide with that of the pipe 10. The air diffusion plates 11 can be fixed by a band having the cross-sectional shape of the opening part corresponding to the cross section of the pipe such as a U-shaped band 14 or the like. Almost all of the arranging area of the pipe can be set to an effective bubbling area and, since the undersurface of the pipe is round, the circulating flow in a tank is hardly obstructed. The holder may be fixed by wrapping the periphery of the holder in a membrane diffuser processed into a bag shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air diffuser having a novel shape used in a sewage treatment plant and the like, and an aeration tank using the same.

[0002]

2. Description of the Related Art The most common diffuser used in a sewage treatment plant is a diffuser plate made of porous porcelain obtained by firing ceramic particles together with a binder. The size of the diffuser plate is almost constant, 300 x 300
A square shape having a size of mm and a rectangular shape having a size of 100 × 300 mm are widely used.

Such a conventional air diffusing plate 1 has been used by being fixed to a holder 2 as shown in FIG. The holder 2 has a U-shaped cross section having horizontal flanges 3 on both sides, and a flat air diffuser plate 1 is placed on the upper surface of the holder 2 and is fixed by a metal fitting 4. The periphery of the bottom surface of the air diffuser plate 1 is sealed by a packing 5. Reference numeral 6 denotes a ventilation pipe, the holder 2 is welded to the upper surface thereof, and the compressed air supplied from the ventilation pipe 6 enters the inside of the holder 2 from the nozzle 7 and becomes fine bubbles in the liquid from the diffuser plate 1. Is released.

However, in such a conventional air diffusing device, the holder 2 is compared with the effective foaming area a of the air diffusing plate 1.
However, there is a drawback that the installation area b is increased. Also,
In a deep tank aeration tank, an air diffuser is installed in the middle stage, and a circulating flow is formed in the tank by using the upward flow accompanying the floating of bubbles, but the conventional air diffuser has a wider holder 2 width. Due to the high resistance of the water flow, it has the drawback of impeding the circulation flow. Particularly, in the aeration tank in which the carrier is charged, a strong circulation flow is required for carrier circulation, and therefore, there is a contradiction that the resistance of the water flow further increases when the number of diffusers is increased.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, can increase the ratio of effective foaming area / installed area, and reduces the resistance of water flow so as not to obstruct the circulation flow. The present invention is made to provide the air diffuser and the aeration tank using the same.

In order to solve the above-mentioned problems, the air diffuser of the present invention according to claim 1 uses a pipe having a semicircular or rectangular cross section as a holder which also serves as a ventilation pipe, and has a plurality of air diffusers on its flat surface. It is characterized by being attached. It is preferable that the rectangular pipe is any of a triangle, a quadrangle, and a pentagon, and it is preferable that the width of the diffuser plate and the width of the cross section of the pipe holder are matched. Also,
The diffuser plate is preferably fixed by a band having an opening cross-sectional shape corresponding to the cross section of the pipe. As the air diffusing plate, in addition to the porcelain air diffusing plate, a porous body made of either a polymer sheet or a filter cloth can be used. Further, the air diffuser of the invention of claim 7 is characterized in that a pipe having a semicircular or square cross section is used as a holder also serving as a ventilation pipe, and the periphery thereof is wrapped and fixed by a membrane diffuser processed into a bag shape. . Furthermore, the aeration tank of the present invention is characterized in that any one of the above air diffusers is installed in the tank.

In the air diffuser of the first aspect of the present invention, a plurality of air diffuser plates are mounted on the flat surface of a pipe having a semicircular or rectangular cross section, so that the ratio of effective foaming area / installation area is increased. You can If the width of the diffuser plate and the width of the pipe holder cross section are matched, the resistance of the water flow will be low even if it is installed in the middle of the circulation flow from the bottom to the top, and the circulation flow will be reduced compared to the conventional product. Do not disturb A rectangular pipe having a triangular, quadrangular or pentagonal cross section may be used, but a semicircular cross section is preferable in consideration of water flow resistance. Further, in the air diffuser of the invention of claim 7, a pipe having a semicircular or rectangular cross section is used as a holder that also serves as a ventilation pipe, and the periphery thereof is wrapped and fixed by a membrane diffuser processed into a bag shape. The ratio of effective foaming area / installed area can be increased similarly to the invention of 1, and does not hinder the circulation flow as compared with the conventional product.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention are shown below. FIG. 1 is a perspective view of an air diffuser of the invention of claim 1, 10 is a pipe made of a corrosion-resistant material such as stainless steel and having a semicircular cross section, 11 is a porous porcelain mounted on the upper surface in a line. It is an air diffuser. The pipe 11 is equipped with a riser pipe 12 to which compressed air is supplied at the end,
As such, it serves both as a ventilation pipe and as a holder for the diffuser plate 11. The material of the pipe 10 and the diffuser plate 11 is not limited to this. The air diffuser plate 11 has a rectangular shape of 100 × 300 mm, for example.

FIG. 2 is a sectional view of the air diffuser according to the first aspect of the present invention. As shown in FIG. 2, a plate-shaped air diffusing plate 11 is placed on the upper flat surface portion of the pipe 10 having a semicircular cross section through a packing 13. The width of the air diffuser 11 is the pipe 1
It is preferable to match the width with 0, but there may be some dimensional difference.

The air diffuser plate 11 is a pipe 10 which serves as a holder.
It is fixed by a U-shaped band 14 to the upper flat portion of the.
Both ends of the U-shaped band 14 extend to a position higher than the air diffuser plate 11, and the pressure plate 17 is pressed by the pressure bolts 16 attached to the bar 15 spanned between the U-shaped band 14 and the air diffusion plate 11. 11 is fixed to the pipe 10. In addition, it is preferable that two adjacent air diffuser plates 11 can be fixed by one U-shaped band 14 by widening the width of the U-shaped band 14 in the axial direction of the pipe. . The band to be fixed can be used even if it is U-shaped or elliptical.

Air supply holes 18 as shown in FIG. 2 are formed in the upper flat portion of the pipe 10 so as to correspond to the mounting pitch of the diffuser plate 11, and the air supply holes are similarly provided at corresponding positions of the packing 13. 19 is formed. For this reason, the compressed air introduced from the riser pipe 12 is
After entering the air chamber 20 formed in the upper part of the packing 13 via 8 and 19, fine air bubbles are diffused from the diffuser plate 11.

In the above-described embodiment, the pipes 10 each having a semicircular cross section are used as holders and the diffuser plates 11 are mounted in a line on the upper surface thereof. However, as shown in FIG. Can also be used. In this case, the diffuser plate 11 is fixed by a band having an opening sectional shape corresponding to the section of the pipe 10.

Further, as shown in FIG. 6, the diffuser plates 11 can be mounted on the upper surface of the pipe 10 in a plurality of rows. Furthermore,
Instead of mounting the diffuser plate 11 on the entire surface of the pipe 10,
As shown in FIG. 7, the air diffuser plate 11 is attached in combination with the non-air-permeable cover 25, or the air supply holes 18 provided in the pipe 10 are widened as shown in FIG. It is also possible to adjust the air diffusion area by fixing it.

As described above, the air diffuser of the present invention has the pipe 1
Since 0 is a holder that also serves as a ventilation pipe, and a plurality of diffuser plates 11 are mounted on the flat surface thereof, the ratio of the effective foaming area to the installation area can be significantly increased as compared with the conventional case. Note that FIG. 3 shows an example of an air diffusing device in which the porous polymer sheet 23 is used as an air diffusing plate and is attached to a form frame 24 having an air diffusing plate shape.

FIG. 4 is a perspective view showing an embodiment of the invention of claim 7, which is an air diffuser in which a membrane diffuser 21 processed into a bag shape is fixed to a semicircular pipe holder 22. Membrane diffuser 21 is 50-30 on the foam surface
A polymer sheet having a large number of holes of 0 μm processed into a bag shape. The membrane diffuser 21 is put on a semi-circular pipe holder 22, and the U-shaped band 14
It is fixed at. The compressed air introduced from the riser pipe 12 is diffused as fine bubbles through the holes of the polymer sheet through the air supply holes.

FIG. 9 shows a baffle plate 31 of the air diffuser of the present invention.
It is sectional drawing which shows the state arrange | positioned in 4 rows in the middle stage of the aeration tank 30 which provided. It is the same as in the prior art that a circulating flow as indicated by an arrow is generated in the tank due to the rising water flow that accompanies the floating of the air bubbles diffused from the air diffuser, and oxygen is uniformly supplied to the entire tank. This water flow passes through between the air diffusers and rises, but the air diffuser of the present invention has a low resistance to the water flow, and in particular, the width of the air diffuser plate 11 has a semicircular cross section as in the embodiment. If the structure is matched with the width of the pipe 10, the resistance of the water flow is significantly reduced.

As described above, the air diffuser of the present invention does not hinder the circulation flow as compared with the conventional product, and therefore is suitable for being installed in the middle of the circulation flow in the middle stage of the aeration tank 30 as shown in FIG. Is. Further, when a carrier (including a microbial carrier) is put into the aeration tank, it is necessary to generate a stronger circulation flow in order to circulate this carrier, but the number of installations is increased in the conventional air diffuser. Therefore, there is a contradiction that the installation area increases and the circulation flow is obstructed. On the other hand, in the air diffuser of the present invention, the flow resistance can be kept low even when the number of installations is increased, and therefore, it is also suitable for use in the aeration tank 30 in which the carrier is charged.

[0018]

As described above, in the air diffuser of the present invention, the ratio of effective foaming area / installation area can be increased by using a pipe having a semicircular or rectangular cross section as a holder. There is an advantage that the resistance of the water flow is reduced and the circulation flow is not obstructed. Furthermore, if a band having an opening cross-sectional shape corresponding to the cross section of the pipe is used, a large number of diffuser plates can be easily fixed, and there is an advantage that equipment cost can be reduced. The air diffuser of the present invention can be laid on the entire bottom surface of the aeration tank, but it is particularly suitable for the middle-stage arrangement or for application to the aeration tank in which the carrier is charged.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the invention of claim 1;

FIG. 2 is a sectional view of the air diffuser of the invention of claim 1.

FIG. 3 is a front view showing another embodiment of the invention of claim 1;

FIG. 4 is an explanatory diagram of an embodiment of the invention of claim 7;
(A) is a perspective view and (B) is a front view.

FIG. 5 is a cross-sectional view showing various types of rectangular pipes.

FIG. 6 is a cross-sectional view showing an example in which the diffuser plates are mounted in two rows.

FIG. 7 is a perspective view showing an example combined with a non-breathable cover.

FIG. 8 is a front view showing another arrangement example of the air diffusing plate on the pipe.

FIG. 9 is a cross-sectional view of an aeration tank in which the air diffuser of the present invention is arranged in the middle stage.

FIG. 10 is a cross-sectional view of a conventional general air diffuser.

[Explanation of symbols]

1 Conventional air diffuser, 2 Holder, 3 collar part, 4 metal fittings, 5 packing, 6 ventilation pipe, 7 nozzle, 10 semi-circular pipe in cross section, 11 air diffuser, 12 riser pipe, 13 packing, 14 U-shape Band, 15 bar,
16 retaining bolts, 17 retaining plate, 18 air supply hole, 19 air supply hole, 20 air chamber, 21 membrane diffuser, 22 semi-circular pipe holder, 23
Porous polymer sheet, 24 Air diffuser plate form, 25
Non-breathable cover, 30 aeration tank, 31 baffle plate

Claims (8)

[Claims] 1. An air diffusing device, wherein a pipe having a semicircular or rectangular cross section is used as a holder that also serves as a ventilation pipe, and a plurality of air diffusing plates are mounted on the flat surface portion. 2. The air diffuser according to claim 1, wherein the prismatic pipe is any one of a triangle, a quadrangle, and a pentagon. 3. The air diffuser according to claim 1, wherein the width of the air diffuser plate and the width of the cross section of the holder are the same. 4. A band having an opening sectional shape corresponding to the section of the pipe is used to fix the diffuser plate.
An air diffuser according to any one of 1. 5. The air diffuser according to claim 1, wherein a porcelain air diffuser is used as the air diffuser. 6. The air diffuser according to any one of claims 1 to 4, wherein a porous body made of either a polymer sheet or a filter cloth is used as the air diffuser. 7. An air diffuser characterized in that a pipe having a semicircular or rectangular cross section is used as a holder that also serves as a ventilation pipe, and the periphery thereof is wrapped and fixed by a membrane diffuser processed into a bag shape. 8. An aeration tank comprising the air diffuser according to claim 1 installed in the tank.