JP2007260529A - Air diffusion nozzle and air diffusion tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air diffusion nozzle capable of efficiently diffusing an air diffusing gas by installing a small-sized air diffusion pipe provided with the air diffusion nozzle in a tank, and an air diffusion tank. <P>SOLUTION: The air diffusion nozzle 10 connected to the air diffusion pipe A in a detachable manner has a pipe 12 opened at its leading end to allow the air diffusing gas to flow and a porous hollow cylindrical body 14, and the pipe 12 opened at its leading end is loosely mounted in the porous hollow cylindrical body 14. By this constitution, a gap C is formed between the pipe 12 and the porous hollow cylindrical body 14. The air diffusing gas flowing through the pipe 12 from the air diffusion pipe A flows in the internal space part of the porous hollow cylindrical body 14 from the leading end of the pipe 12 and passes through the gap C between the pipe 12 and the porous hollow cylindrical body 14 to be uniformly diffused over the whole surface of the porous hollow cylindrical body 14. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an air diffuser nozzle attached to an air diffuser for diffusing gas for air diffusing into an air diffuser and a diffuser tank using the air diffuser nozzle.

Organic sewage generated in large quantities, such as sewage wastewater and factory wastewater, is efficiently treated in an aerobic or anaerobic atmosphere by a sewage treatment system equipped with a biological treatment device such as an activated sludge aeration tank ( For example, see Patent Document 1).
In such an aeration tank of a sewage treatment system, a large number of aeration nozzles are provided in an aeration tube stretched in a large tank, and aeration gas such as air or oxygen-enriched air is discharged from the aeration nozzle. It is diffused into the water in the tank, and the dissolved oxygen amount in the water is maintained at a predetermined concentration. In addition, it may replace with a diffuser nozzle and the diffuser board which consists of a porous board may be used.

  The diffuser nozzle used in the aeration tank or the like is usually cylindrical, and in some cases, the diffuser gas is diffused from countless holes opened in the diffuser tube by omitting such a diffuser nozzle. There are many.

  On the other hand, in order to treat sewage such as human waste generated in detached houses and collective houses, a septic tank is often provided for each source of sewage, and in this case, a fixed bed type biological treatment device is provided, A diffuser tube and a diffuser nozzle similar to those in the aeration tank of the sewage treatment system are used.

Further, for example, in a commercial kitchen such as a restaurant, wastewater containing a high concentration of oil or the like is discharged although the amount generated is not so large. For this reason, for example, in Japan, installation of a grease interceptor is obligated by notification from the Ministry of Land, Infrastructure, Transport and Tourism. Furthermore, there are places where the concentration of oil and other oils is regulated for establishments that discharge a certain amount or more of wastewater due to local government regulations.
In order to achieve the above-mentioned concentration regulation standards, a biological treatment apparatus similar to the above-described septic tank is provided, and the biological treatment function is not inhibited by high-concentration oil, so that the primary treatment It is necessary to provide an aeration tank as a primary treatment layer (preliminary tank) for preliminarily decomposing oil. In addition, in order to prevent oil discharged from clogging water distribution pipes, etc., even in places where concentration regulations are not applied, drainage pits (soots) called grease traps that collect grease-like fats and oils are used. It is necessary to provide it.
Such a primary treatment layer or drainage pit has a relatively small tank so that it does not take up a lot of space because it requires a relatively small amount of wastewater to be treated and needs to be provided individually in restaurants, etc. For example, a small capacity of about 100 liters is used.
In the primary treatment layer, oxygen-enriched air or ozone-enriched air is often used as the gas for aeration. However, the aeration tube equipped with the aeration nozzle is the same as the aeration layer and septic tank. Is used. However, according to the scale down of the treatment layer, for example, the holes for air diffusion are formed with a small diameter of about 1 mm, for example. In addition, an inexpensive resin is often used as a material for the air diffuser.
JP 2005-246185 A

However, in the case of a cylindrical air diffuser nozzle or hole attached to a diffuser used as a conventional air diffuser or the like as the above-mentioned primary treatment layer, for example, it is installed in a small-capacity tank so that the water in the tank (sewage efficiently) Medium) is not necessarily sufficient for dissolving gas for aeration such as ozone-enriched air, particularly oxygen and ozone. That is, for example, bubbles of air diffused gas that flows out into the water from a hole with a diameter of about 1 mm formed in the air diffuser gather in the process of ascending underwater at a depth of about several tens of cm, for example, about 10 mm. Since it becomes a bubble of a diameter, the contact efficiency with water is bad, and therefore the air diffusion efficiency is bad.
Further, with respect to the conventional drainage pit, the work of periodically collecting the accumulated oily oil is complicated, and the frequency of collection cannot be ignored.

  The present invention has been made in view of the above problems, and an air diffuser that can efficiently diffuse air for diffusion by installing a small air diffuser tube provided with an air diffuser nozzle in the tank. An object is to provide a nozzle and an air diffuser.

  In order to achieve the above object, an air diffuser nozzle according to the present invention comprises a tube with an open end that circulates the gas for diffusion, and a porous hollow cylinder that is closed at the tip and loosened. It is characterized by having.

  In addition, the aeration nozzle according to the present invention is characterized in that a large number of holes are formed in the tube wall of the tube.

  The diffuser nozzle according to the present invention is characterized in that the porous hollow cylindrical body is formed of a porous metal material or a porous inorganic material.

  Further, an air diffuser according to the present invention is an air diffuser in which an air diffuser pipe for supplying an air diffuser is provided, and the air diffuser described above extends from the air diffuser toward the bottom surface. It is characterized by providing.

  Moreover, the diffuser tank according to the present invention is characterized in that the tip of the diffuser nozzle is disposed at a position 5 to 15 mm away from the bottom surface.

  Moreover, the aeration tank according to the present invention is characterized in that ozone-containing air is used as an aeration gas to chemically treat oil in sewage containing oil.

The air diffusion nozzle according to the present invention has a tube having an open end that circulates the gas for air diffusion and a porous hollow cylindrical body in which the end is closed and the tube is loosened. Since the gas for aeration that has flowed into the hollow cylinder passes through the gap between the tube and the cylinder and is uniformly diffused over the entire surface of the cylinder, the gas has a diameter of, for example, Since air is diffused in the form of bubbles having a fine surface area of about 100 μm and a large specific surface area (surface area per unit gas amount of bubbles), it is possible to efficiently diffuse.
In addition, since the air diffuser according to the present invention is provided with the above air diffuser nozzle so as to extend from the air diffuser toward the bottom surface, the tip of the air diffuser nozzle is located near the bottom surface of the air diffuser. By arranging the diffuser pipe in this manner, the height (depth) dimension of the diffuser tank can be reduced and the diffused air can be efficiently diffused. Since the air is reliably diffused, there is little possibility that the tip of the air diffuser nozzle is clogged by sludge deposited in the tank.

  A preferred embodiment (hereinafter referred to as this embodiment) of an air diffusion nozzle and an air diffusion tank according to the present invention will be described below with reference to the drawings.

  First, the air diffusion nozzle according to the present embodiment will be described with reference to FIG. FIG. 1 shows the appearance of an air diffuser nozzle on the left side with a center line extending in the vertical direction, and the internal structure of the air diffuser nozzle broken to include the center line on the right side. .

  As shown in FIG. 1, a diffuser nozzle 10 according to the present embodiment, which is detachably connected to a female screw portion of a diffuser tube (indicated by arrow A in FIG. 1), shows a diffused gas. The tube 12 circulates in the direction indicated by the white arrow and is open at the tip (indicated by the arrow P1 in FIG. 1) and the porous hollow cylindrical body 14. The tip of the porous hollow cylinder 14 is closed (indicated by an arrow P2 in FIG. 1), and the tube 12 is loosely mounted. Thereby, a gap (indicated by an arrow C in FIG. 1) is formed between the tube 12 and the porous hollow cylindrical body 14.

  For example, when a single aeration nozzle 10 diffuses about 0.25 liters per minute, the length L is about 15 mm and the diameter D is about 12 mm. The diameter of the hollow portion of the porous hollow cylindrical body 14 and the diameter of the tube 12 are set to appropriate dimensions within a range limited by the length L and the diameter D in consideration of the amount of air diffused.

  The material of the pipe 12 is not particularly limited, but from the viewpoint of preventing corrosion due to sewage to be treated or a gas used for diffusion, it is preferable to use a corrosion-resistant metal or a corrosion-resistant resin, and further, from the viewpoint of material cost. Considering this, it is more preferable to use a resin such as a vinyl chloride resin. In addition, the edge part by the side of the pipe | tube 12 connected to the diffuser pipe A is formed in the taper shape, and makes the distribution | circulation resistance of the gas for aeration small.

The material of the porous hollow cylinder 14 is not particularly limited as long as it is porous, but in consideration of durability, a porous metal material or a porous inorganic material is preferably used. Moreover, a corrosion-resistant material is used from the viewpoint of preventing corrosion due to sewage to be treated or gas used for aeration.
As such a porous metal material, for example, a porous molded body obtained by sintering metal powder such as stainless steel (SUS material) can be suitably used. As the porous inorganic material, a porous molded body obtained by sintering ceramic powder, carbon powder, or the like can be suitably used. The porous hollow cylindrical body 14 formed of such a material has an infinite number of pores having a diameter of, for example, about 70 μm or less that communicate the hollow portion with the outside.

In the diffuser nozzle 10 configured as described above, the diffused gas flowing from the diffuser pipe A to the pipe 12 flows into the internal space of the porous hollow cylindrical body 14 from the tip of the pipe 12, and the porous nozzle 12 and the porous nozzle 10 are porous. Through the gap C between the porous hollow cylinders 14, it is spread over the entire surface of the porous hollow cylinder 14 and is uniformly diffused.
At this time, the gas for aeration is diffused from pores having a fine diameter, for example, in the form of bubbles having a diameter of about 100 μm and a large specific surface area (surface area per unit amount of bubbles). Even when gathering when ascending underwater at a depth of about 15 cm, it stops at the aggregated bubble with a diameter of about several millimeters at most, so the gas for aeration can be efficiently diffused.
In addition, even when the gas for aeration has a large flow velocity at the time of flowing through the pipe 12, the gas is reduced through the fine pores of the porous hollow cylindrical body 14 and flows out, so that it reaches the water surface. When this occurs, the splashes generated by the bursting of the bubbles are reduced, and there is little risk of fouling the surroundings. This is beneficial for preventing scattering of germs and the like when, for example, sewage is aerated. Incidentally, the gas for aeration diffused from one aeration nozzle 10 forms a bubble column having a diameter of about 10 cm in water.
The air diffusion nozzle 10 may form a large number of holes of an appropriate size on the tube wall of the tube 12, and thereby, the gas for air diffusion may be balanced from the large number of holes to the hollow portion of the porous hollow cylindrical body 14. It is allowed to flow out and uniformly diffuse from the porous hollow cylindrical body 14.

  Next, an aeration tank according to the present embodiment using the aeration nozzle 10 according to the present embodiment will be described with reference to FIG. FIG. 2 shows a rectangular parallelepiped aeration tank provided with an aeration tube to which an aeration nozzle 10 is attached, omitting the two side walls and the upper part on the front side.

The aeration tank 16 shown in FIG. 2 is supported by a support member 17 and is provided with an aeration pipe 18 formed of, for example, SUS material in a substantially H shape at the bottom of the tank. A connection portion A of the diffuser pipe 18 provided to be further bifurcated from each of the four H-shaped end portions is connected to the diffuser nozzle 10 so as to project toward the bottom surface of the tank. The diffuser nozzle 10 is connected to the connection portion A and is provided so as to extend toward the bottom surface of the tank. Thereby, the front-end | tip of the aeration nozzle 10 can be arrange | positioned in the position which 5-15 mm apart from the bottom face of the tank, for example.
In FIG. 2, eight diffuser nozzles 10 are shown to be provided in the tank. Specifically, for example, when the capacity of the diffuser tank 16 is about 100 liters, the diffuser pipe 18 is provided. Furthermore, a large number of rows are arranged and about 16 to 20 aeration nozzles 10 are provided. Further, in FIG. 2, reference numeral 20 indicates an aeration gas supply source (not shown) and an aeration tank 16 when adjusting the aeration flow rate at the time of aeration and when the aeration tank 10 is stopped. The original valve for blocking the gap is shown. At this time, if a check valve is provided in the vicinity of the original valve 20 as necessary, it is ensured that the water to be treated in the air diffusion tank 16 flows backward in the air diffusion pipe 18 toward the gas supply source for air diffusion. Can be prevented.

  The air diffusion tank 16 configured as described above has a height of the air diffusion tank 16 by disposing the air diffusion pipe 18 so that the tip portion of the air diffusion nozzle 10 is positioned near the bottom surface of the air diffusion tank 16. The (depth) dimension can be reduced, and air can be efficiently diffused. At this time, since the air is reliably diffused from the front end portion of the air diffuser nozzle 10, there is little possibility that the front end portion of the air diffuser nozzle 10 is blocked by sludge deposited in the tank.

Next, an example in which the aeration tank according to the present embodiment is used for a grease trap of a restaurant will be described with reference to FIG.
The grease wrap is installed in a restaurant's kitchen, for example, ozone generated from an ozone generator so that wastewater containing high-concentration oil, such as cooking oil, is not discharged into the sewage pipe as it is. Is supplied into waste water to oxidatively decompose aliphatic hydrocarbons and alcohols (chemical treatment).

As shown in FIG. 3, the grease strap 22 is composed of, for example, three tanks as in a normal case.
The first tank 24 is, for example, for pre-processing (primary processing) wastewater, and includes, for example, a collection net jar 26, and appropriately takes out and disposes of relatively large garbage such as food residue. A highly viscous grease-like oil component floats and stays in the upper part of the first tank 24. Note that an oil collecting net can be provided as necessary.
The second tank 28 is an air diffusion tank according to the present embodiment, and the air diffusion pipe 18 is disposed so that the tip portion of the air diffusion nozzle 10 is located near the bottom surface of the second tank 28. For example, air containing ozone is diffused from the diffuser nozzle 10, and the oil flowing into the second tank 28 is oxidized and decomposed. As a result, the highly viscous grease-like oil changes into a relatively smooth sludge shape and further into a liquid state.
The wastewater treated in the second tank 28 flows into the third tank 30 and is discharged from the trap pipe 32. At this time, the oil whose properties have been improved to such an extent that there is no possibility of clogging the water distribution pipe is also discharged from the trap pipe 32.
In the second tank 28 and the third tank 30 as well, the oil component floats and stays in the upper part over time. For this reason, in the 1st tank 24, the 2nd tank 28, and the 3rd tank 30, the work which collects oil content to some extent is required, but compared with the conventional device, the work frequency is reduced and workability is reduced. Improved.

In the grease trap 22 configured as described above, the air diffuser 16 according to the present embodiment used as the second tank 28 has a structure in which the air diffuser including the air diffuser and the air diffuser is simplified and miniaturized. Therefore, the construction is easy both in the case of installation in the field in a state of being assembled in advance and in the case of assembly in the field. Further, when the grease strap 22 is regularly cleaned, the air diffuser can be taken out from the second tank 28 with one touch, so that the cleaning work is easy. Further, if necessary, the diffuser nozzle can be easily attached and detached from the diffuser tube.
In the grease strap 22 described above, it is more preferable to use the air diffusion tank according to the present embodiment for the first tank 24 and the third tank 30 as well. Moreover, when high-order processing, such as BOD in waste_water | drain, is required, the grease trap 22 is made into a pretreatment tank, and the aeration tank etc. which biochemically process the water after a pretreatment are further provided, for example.

The air diffusion tank 16 according to the present embodiment can be suitably used when chemically treating oil in wastewater containing oil using ozone-containing air as described above, but is not limited thereto. Needless to say, the present invention can also be suitably used for biological treatment.
Further, the air diffusion tank 16 according to the present embodiment is particularly useful in a small processing apparatus, but is not limited to being applied to a large processing apparatus. .

  The present invention will be further described with reference to examples and comparative examples. In addition, this invention is not limited to the Example demonstrated below.

(Example)
An air diffuser equipped with four air diffuser nozzles of the present invention was placed in a 12 liter water tank, and 10 liters of pure water was added. The water depth at this time is about 15 cm, and the water temperature is 25 ° C. The water tank was sealed except that a gas vent hole with a diameter of 16 mm was provided. The air pump distributed and supplied 10 liters of air per minute to the four aeration nozzles, an ozone generator was provided between the air pump and the water tank, and 40 ppm of ozone was contained in the shared air.
After aeration for 1 hour, lard 5 g and beef tallow 5 g as oils and fats were dissolved in pure water, and the aeration was continued for 1 hour.
Then, the ozone concentration of the sealed space on the water surface was measured using 10 gas detection tubes (Gastech's ozone detection tube 18M). The average value of the ozone concentration was a trace (1 ppm or less). Moreover, the oil in pure water was emulsified and in a smooth state. The air discharged from the vent hole had a slight ozone odor.

(Comparative example)
Using a water tank and water under the same conditions as in the example, air containing ozone was supplied to the water tank under the same conditions as in the example.
At this time, in place of the diffuser of the example, a diffuser having a total of 14 holes of 1 mm at 2 cm intervals in a 20 cm long PVC pipe with a total of 14 holes was used. The ozone concentration in the sealed space on the water surface was measured under the conditions. The average value of ozone concentration was 30 ppm. Moreover, the oil in pure water was only slightly emulsified. The air discharged from the vent hole had an extreme ozone odor.

It is a figure for demonstrating the diffuser nozzle which concerns on the example of this Embodiment. It is a figure for demonstrating the air diffusion tank which concerns on the example of this Embodiment. It is a figure for demonstrating the grease strap using the air diffusion tank which concerns on the example of this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Aeration nozzle 12 Pipe | tube 14 Porous hollow cylindrical body 16 Aeration tank 17 Support member 18 Aeration pipe 24 1st tank 26 Recovery net tank 28 2nd tank 30 3rd tank 32 Trap pipe

Claims (6)

  An air diffusion nozzle comprising: a tube having an open end through which a gas for air diffusion is disposed; and a porous hollow cylindrical body in which the end is closed and the tube is loosened.   The aeration nozzle according to claim 1, wherein a plurality of holes are formed in a tube wall of the tube.   The aeration nozzle according to claim 1 or 2, wherein the porous hollow cylindrical body is formed of a porous metal material or a porous inorganic material.   An aeration tank in which an aeration tube for supplying an aeration gas is disposed, and the aeration nozzle according to any one of claims 1 to 3, extending from the aeration tube toward the bottom surface. An air diffusion tank characterized by comprising   The aeration tank according to claim 4, wherein a tip of the aeration nozzle is arranged at a position 5 to 15 mm away from the bottom surface. 6. An aeration tank according to claim 4 or 5, wherein ozone-containing air is used as an aeration gas to chemically treat oil in wastewater containing oil.

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