JPH0660494U - Air diffuser - Google Patents

Abstract

(57) [Summary] [Objective] To provide an air diffuser capable of obtaining high oxygen transfer efficiency by generation of fine bubbles and having low head loss. [Structure] A cylindrical air diffuser nozzle 2 is attached to a header tube 1 by a U-shaped bolt 7 in a hanging shape. Aeration nozzle 2
A plurality of slits 6 having a wedge-shaped axial section that gradually expands to the outer surface thereof and extending in the circumferential direction are formed on the peripheral wall of the. Air is ejected in a thin film form from each slit 6, and the thin film bubbles are sheared into fine bubbles immediately after ejection.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an air diffuser installed in an aeration tank or a conditioning tank of a sewage treatment facility.

[0002]

[Prior art]

 Generally, conventional air diffusers are roughly classified into a fine bubble type using a porcelain, a synthetic rubber film and the like and a coarse bubble type using a porous nozzle.

[0003]

[Problems to be solved by the device]

 However, in the micro-bubble type, while high oxygen transfer efficiency can be obtained due to the generation of micro-bubbles, the head loss is high and the diffuser surface is also easily blocked. In addition, the structure becomes complicated and it is necessary to regularly replace the consumable parts. On the other hand, the coarse bubble type does not have such drawbacks and has structural advantages such as a simple structure and high durability, but it cannot obtain fine bubbles and has a low oxygen transfer rate. There is a functional defect such as. As described above, each of them has advantages and disadvantages, and it is impossible to exhibit and maintain a good aeration function for a long period of time.

The present invention has been made in view of the above points, and has the advantages of both the fine bubble type and the coarse bubble type, and can exhibit a good aeration function for a long period of time, both functionally and structurally. It is also an object of the present invention to provide an excellent air diffuser.

[0005]

[Means for Solving the Problems]

 An air diffuser of the present invention which solves this problem comprises a cylindrical air diffuser nozzle. A plurality of slits extending in the circumferential direction are formed on the peripheral wall of the air diffusion nozzle, the slits having a wedge-shaped cross section in the axial direction and gradually expanding to the outer surface thereof.

[0006]

[Action]

 When air is supplied to the nozzle, it is ejected as a thin film from each slit. Unlike a spherical bubble, this thin film bubble is immediately sheared into a fine bubble immediately after being ejected from the slit, due to the surface tension, and an extremely fine bubble is generated. become.

[0007]

【Example】

 Hereinafter, the configuration of the present invention will be specifically described based on the embodiments shown in FIGS.

As shown in FIG. 1, the air diffuser of this embodiment has a plurality of header pipes 1 (in this embodiment, a header pipe 1 horizontally arranged in a tank (aeration tank or adjustment tank of a horizontal processing facility)). 4) diffusing nozzles 2 are provided so as to project downward. The header pipe 1 has a diameter of 50 A, and air is supplied from an air supply source (not shown) such as a blower through the air supply pipe 3.

As shown in FIGS. 2 to 8, each air diffuser nozzle 2 is composed of a main body portion 4 and a collar portion 5 for mounting, and is integrally molded of a synthetic resin material such as ABS resin.

The main body portion 4 has a cylindrical shape with a downward constriction (the outer diameter of the upper end opening 4 a is 25 m, the inner diameter of the portion 4 a is 19 mm, the lower end opening 4 b is the outer diameter of 22 mm, the inner diameter of the portion 4 b is 15 mm, and the lower part of the collar is The length of the portion 4c is 92 mm). As shown in FIGS. 7 and 8, the peripheral wall of the main body portion 4a is provided with a plurality of slits 6 ... Having a wedge-shaped axial section that gradually expands to the outer surface and extending in the circumferential direction. In this embodiment, a pair of eighteen slit groups 6 arranged in parallel in the axial direction are formed in the peripheral wall of the lower portion 4c of the collar portion so as to radially face each other. The width is set to 1 mm. Further, bolt engaging grooves 5a, 5a capable of engaging the U-shaped bolt 7 are formed at both ends in the longitudinal direction of the collar portion 5, and the peripheral surface of the header pipe 1 is provided at both ends in the width direction. Engaging projections 5b, 5b having arcuate recesses that can be engaged with are formed. The upper end opening 4a of the main body 4 is projected onto the collar 5 between the engaging projections 5b and 5b.

As shown in FIG. 2, each air diffuser nozzle 2 has an upper end opening 4a that is inserted into a mounting hole (not shown) formed in the lower surface of the header tube 1 and the header tube With the engaging protrusions 5b, 5b engaged with the lower surface of the No. 1, engage with the bolt engaging grooves 5a, 5a at both ends of the U-shaped bolt 7 engaged with the header pipe 1. After that, the nuts 8 and 8 are screwed and fastened to each other, so that the nuts 8 are attached to the header pipe 1 in a hanging manner. According to the nozzle mounting structure using the U-shaped bolt 7 as described above, the nozzle 2 can be mounted easily and surely without the need for a seal member. In order to secure the fastening with the nut 8, it is desirable to provide a loosening prevention means such as idling or a double nut.

According to the air diffuser configured as described above, when air is supplied to the header pipe 1, it is ejected in a thin film form from each slit 6. Then, unlike the spherical bubbles, the thin film-like bubbles are immediately sheared into fine bubbles due to the surface tension immediately after being ejected from the slit 6, and thus extremely fine bubbles are formed. Can be generated. By the way, as shown in FIG. 9, the slit region for ejecting bubbles expands downward as the air volume supplied to the air diffusion nozzle 2 increases, and when the air volume increases rapidly, , It will be released from the lower end opening 4b. In FIG. 9, FIG. A shows a case where the air supply amount per nozzle is 100 l / min, B diagram shows a case of 300 l / min, and C diagram shows a case of 500 l / min. Each one is shown.

Therefore, it is possible to achieve the same high oxygen transfer efficiency as that of the micro-bubble type due to the generation of the micro-bubbles, the head loss is extremely small, and energy saving can be realized. This is confirmed by an experiment conducted using the apparatus of the above-mentioned embodiment. 10 to 12 show the experimental results, and FIG. 10 shows the amount of air supply and the oxygen transfer rate per nozzle when the nozzle water depth is 4 m (shown by the solid line) and 3 m (shown by the chain line). Fig. 11 shows the relationship between nozzle water depth and oxygen transfer efficiency when the air supply amount per nozzle is 280 l / min, and Fig. 12 shows the air supply amount and pressure per nozzle. The relationship with loss is shown respectively.

Further, since the slit 6 has a wedge-shaped cross-sectional shape that expands outward, even if a foreign matter enters the slit 6 when the operation is stopped, air is ejected from the slit 6 so that the foreign matter can be easily introduced. It can be eliminated and there is no risk that the slit 6 will be blocked. Therefore, since it can exert such a non-clock effect, it can be suitably used for a treatment method (intermittent aeration method, etc.) of organic wastewater which needs to frequently start and stop the air diffuser action.

The present invention is not limited to the above-mentioned embodiments, but can be appropriately improved and modified within a range not deviating from the basic principle of the present invention.

For example, in the above-described embodiment, 18 slit groups 6 ... Are provided in two rows, but the number of slit groups 6 ... It can be set as appropriate. Of course, the shape and size of each slit 6 are appropriately set according to various conditions such as the shape of the nozzle 2 and the blow load. Further, the number of nozzles 2 is also arbitrary and is appropriately set according to the aeration conditions and the like. Further, the nozzle 2 may be attached to the header pipe 1 by an adhesive or the like in a non-removable manner, and in this case, the attaching collar portion 5 or a similar portion does not necessarily require this. Of course, the structure of the air supply header such as the header pipe 1 to which the nozzle 2 is attached is also arbitrary, and the header and the nozzle 2 may be integrally formed depending on the shape and structure of this header. Further, the nozzle 2 or the main body portion 4 may be formed in a tubular shape having a uniform cross section instead of the tapered shape as in the above embodiment. As a matter of course, the cross-sectional shape is arbitrary as long as it can form an appropriate shape and the number of slits 6, and in addition to the circular shape, it may be a polygonal shape such as an elliptical shape, a rectangular shape, a triangular shape, a pentagonal shape. Further, the constituent materials of the header tube 1, the nozzle 2 and the like can be arbitrarily selected, but it is generally preferable to select one having excellent corrosion resistance and the like.

[0017]

[Effect of device]

 As is clear from the above description, according to the present invention, it is possible to generate fine bubbles and obtain the oxygen transfer efficiency as high as that of the fine bubble type. Moreover, the pressure head is low, and there is no blockage due to foreign matter. In addition, the structure is simple and maintenance is easy, which is advantageous in manufacturing economy. Therefore, the air diffuser of the present invention has the advantages of the conventional fine bubble type and the coarse bubble type, and can eliminate the disadvantages and exhibit a good aeration effect over a long period of time. It is a huge one and can easily realize an inexpensive and highly efficient plant design.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of an air diffuser according to the present invention.

FIG. 2 is a perspective view showing an enlarged main part thereof.

FIG. 3 is a front view of an air diffusion nozzle.

FIG. 4 is a plan view of the same.

FIG. 5 is a side view of the same.

FIG. 6 is a bottom view of the same.

7 is a sectional view taken along line VII-VII of FIG.

8 is a sectional view taken along line VIII-VIII of FIG.

FIG. 9 is an explanatory diagram showing an aeration state.

FIG. 10 is a graph showing a relationship between an air supply amount of an air diffusion nozzle and an oxygen transfer rate.

FIG. 11 is a graph showing the relationship between the water depth of the diffuser nozzle and the oxygen transfer efficiency.

FIG. 12 is a graph showing the relationship between the air supply amount of the air diffusion nozzle and the pressure loss.

[Explanation of symbols]

1 ... Header tube, 2 ... Aeration nozzle, 6 ... Slit, 7 ... U
Letter bolt.

Claims (1)

[Scope of utility model registration request] 1. A cylindrical air diffuser nozzle is provided, and a plurality of slits extending in the circumferential direction having a wedge-shaped axial section that gradually expands to the outer surface of the diffuser nozzle are provided. An air diffuser characterized by being formed.