JP5062138B2 - Cleaning method for air diffuser - Google Patents

Description

  The present invention relates to a method for cleaning an air diffuser, and more particularly, to a method for cleaning an air diffuser that can reliably remove dirt components attached to an air diffuser surface of an air diffuser plate.

  In order to remove nitrogen compounds and carbon compounds in sewage at a sewage treatment facility, an activated sludge method utilizing decomposition and adsorption by microorganisms is used. In order for the microorganisms in the activated sludge to be active, it is necessary to give oxygen to the microorganisms. The air diffuser is an apparatus that is installed at the bottom of an aeration tank of a sewage treatment facility and supplies oxygen into water. There are two types of diffusers: a diffuser with a film diffuser surface (Patent Document 1) and a diffuser with a metal thin plate type diffuser surface (Patent Document 2). The thin metal plate type air diffuser has less pressure loss due to air diffused, and is excellent in durability and ease of maintenance and inspection.

  When the aeration apparatus continues aeration operation for a long period of time, the dirt component adheres to the inside and the surface of the fine holes of the film or the metal thin plate, thereby causing clogging. Most of the soil components that cause clogging are slimes formed by microorganisms, which block the air holes. The slime has a strong adhesive force, and the slime cannot be peeled off even if the gas pressure is increased.

  In the membrane-type air diffuser, a method is disclosed in which the membrane is elongated or contracted by the air-feeding operation of the air diffuser to remove the microorganism-derived slime attached to the inside and the surface of the micropores of the membrane (Patent Document 3). ).

  However, in the thin metal plate type air diffuser, since the air diffused surface is a rigid body having no elasticity, the above-described clogging prevention treatment cannot be performed. At present, when clogging occurs due to the growth of microorganisms in a thin metal plate type diffuser, the diffuser plate must be cleaned by lifting the diffuser onto the water surface. Management requires a lot of labor and expense.

In both the membrane type and the thin metal plate type, it is necessary to reduce the pore diameter of the diffuser surface in order to increase the oxygen transfer efficiency. However, the smaller the pore diameter, the more likely clogging occurs. Air diffusers that are prone to clogging must be lifted above the surface of the water and frequently cleaned.
JP 2003-320388 A JP 2006-61817 A JP 2004-313938 A

Thus, the conventional diffuser has not been provided with a sufficient solution to the clogging problem.
Therefore, in the present invention, when the diffuser surface is clogged due to long-term use, the diffuser plate is pulled up to the water surface even with respect to the diffuser plate which is a rigid body having no elasticity. It is an object of the present invention to provide a cleaning method for an air diffuser that can eliminate clogging of the air diffuser surface without cleaning.

  In order to solve the above-mentioned problem, the inventor injects water or cleaning water such as a chemical solution into the air supply pipe for air diffusion, and supplies the air to the air diffusion plate side with air for air diffusion. We considered automatic cleaning of slime (biofilm) adhering to the plate. As a specific means for realizing this, an internal intubation is provided in which one end communicates with the air diffuser plate and the other end is inserted into the air supply pipe for air diffusion, and cleaning is performed via the internal intubation. We considered supplying water to the diffuser and blowing water.

However, if the biofilm completely adheres to the diffuser plate for some reason, it is difficult to completely remove the biofilm by water blow, and aeration due to a decrease in oxygen transfer efficiency and an increase in the pressure loss of the diffuser. It is inevitable that the power will be greater than the initial installation.
Therefore, the inventor examined the removal of the biofilm formed on the diffuser plate by chemically decomposing it as a method of effectively removing the biofilm attached to the diffuser wall of the diffuser plate. It has been found that alkali is effective in removing biofilms. This is because the biofilm is a mass of microorganisms, the protein is the main component, and the alkali dissolves the protein.

By the way, in the case of water blow, the slime is physically removed, and the blow time is only a few minutes.
On the other hand, decomposing and removing proteins with alkali is a chemical reaction and requires some time. In addition, during this decomposition action time, the inside of the aeration tank (header pipe) always maintains a positive pressure with respect to the pressure of the aeration tank sewage so that the sewage in the aeration tank does not flow back to the diffusion surface. Must do so. This is because when the sewage flows backward, a metal salt such as aluminum in the sewage reacts with the alkali on the diffuser plate to precipitate solids and clogs the openings of the diffuser plate.

As a method of injecting the alkaline liquid while preventing such a backflow, the alkaline liquid is injected into the acid supply pipe (header pipe) until it becomes full, and the alkali decomposes the biofilm 30. It is conceivable to always supply the alkaline solution for about a minute.
However, in this method, an excessive amount of alkali solution must be injected relative to the amount necessary to decompose the biofilm, which is not economical and a large amount of alkali is mixed in the aeration tank. There are concerns about the negative impact on activated sludge.
Therefore, as a result of intensive studies to solve this problem, the inventor injected a required amount of alkaline liquid into the air supply pipe (header pipe) for air diffusion, and then into the air supply pipe for air diffusion in the sealed state. By continuously injecting a small amount of air, the alkaline liquid stored in the air supply pipe (header pipe) for air diffusion can be pushed out and supplied to the air diffuser plate via the intubation tube over time. And gained knowledge.
The present invention has been made based on such findings, and specifically has the following configuration.

(1) A method of cleaning an air diffuser according to the present invention includes an air diffuser plate having fine pores installed in an aeration tank, an air supply pipe for air diffuser connected to the air diffuser plate, and the air diffuser. An air supply device connected to the air supply pipe via an open / close valve to supply air for air supply to the air supply pipe for air diffusion, one end connected to the air diffusion plate, and the other end to the air supply for air diffusion A method of cleaning an air diffuser comprising an intubation inserted in an air pipe,
A pressurized air supply device for injecting pressurized air into the air supply pipe for air diffusion, and a chemical liquid injection device for injecting a cleaning chemical into the air supply pipe for air diffusion,
After stopping the supply of the air diffuser for air to air air supply piping scattered by closing the on-off valve, the cleaning agent liquid supply for supplying a cleaning agent liquid feeding to sign tube for the air diffuser by the liquid injector a step, and continuously supplied to the pressurized air supply device by said air diffuser for supply to the sign tube pressurized air 30 minutes to several hours, through the intubation cleaning agent liquid of the air diffuser for supply quotations tube further comprising a diffuser plate chemical cleaning process of discharging continuously dispersed from the vapor plate Te is characterized in.

(2) Further, in those described in the above (1), provided with a blowing water supply means for supplying blow water supply quotations tube for aeration, after washing with the washing agent solution, for air diffuser by the blow water supplier It has a water blow process for supplying blow water into the air supply pipe and blowing air into the air supply pipe for supplying air and supplying the blow water to the air diffuser plate through the intubation to blow water. It is characterized by this.

(3) Further, in those described in the above (2), cleaning agent liquid is characterized in that a chemical solution composed mainly of an alkali.

(4) In those described in the above (3), irrigant fluid, it is characterized in that it contains sodium carbonate.

  According to the method for cleaning an air diffuser of the present invention, the biofilm adhered to the air diffuser is effectively removed without lifting the air diffuser to the surface of the water, and the clogging of the air diffuser is eliminated. can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1. Air diffuser FIG. 1 is a schematic diagram showing an air diffuser according to the present embodiment. In the present embodiment, a case where a chemical liquid containing alkali as a main component (hereinafter referred to as “alkaline liquid”) is used as an example of the cleaning liquid will be described.
The air diffuser 1 according to the present embodiment includes a gas supply means 2, an air supply pipe 3 (header pipe) for guiding air supplied from the gas supply means 2 to an air diffuser plate, and an air supply for air diffusion. A diffuser plate 4 that receives supply of air for aeration from the pipe 3 and releases fine bubbles, an upper end connected to the aeration plate 4, and a lower end inserted into the aeration air supply pipe 3. Pressurized air is injected into the air supply pipe 3 through the intubation 7, the chemical liquid injection device 14 that injects the alkaline liquid into the air supply pipe 3 through the chemical liquid injection pipe 13, and the air supply pipe 3 through the air injection pipe 15. And a blow water supply means 5 for supplying blow water to the air supply pipe 3 for diffusion through a blow water supply pipe 17.

An opening / closing valve 18 is provided in the air supply piping 3, an opening / closing valve 19 is provided in the chemical solution injection pipe 13, an opening / closing valve 20 is provided in the air injection pipe 15, and an opening / closing valve 21 is provided in the blow water supply pipe 17. Are provided.
Hereinafter, the main configuration of the air diffuser 1 will be described in detail.

<Air diffuser>
The diffuser plate 4 may be any form of diffuser plate such as a membrane type or a thin metal plate type. For example, when the diffuser plate 4 is a thin metal plate type, a thin metal plate having fine holes or slits formed by machining is used.
The air supplied from the gas supply means 2 is supplied to the diffuser plate 4 from the diffuser supply pipe 3 through the inner tube 7 and discharged from a plurality of diffuser holes scattered on the diffuser surface of the diffuser plate 4. Is done.

<Intubation>
Since the air diffuser 1 according to the present embodiment includes the inner intubation tube 7, water is supplied to the air diffuser holes of the air diffuser plate 4 without filling the air diffuser air supply pipe 3 with water. Can blow. Therefore, a large amount of water is not required. In particular, when an aqueous solution containing an antibacterial substance is supplied, microorganisms can be efficiently removed in a short time with a small amount of the antibacterial substance. As a result, the biofilm can be prevented from adhering to the diffuser plate 4 and the number of times of chemical cleaning can be reduced, so that the diffuser can be operated stably for a long time under the surface of the water.

  In the case where there is no internal intubation 7, when trying to supply water for blowing the air diffuser plate 4, it is not only necessary to fill the air supply pipe 3 for air diffusion as described above, It is necessary to devise in order to drain water. If there is no means for draining water, water remains in the air supply piping for the air diffuser to which the air diffuser plate 4 is attached, the pipe line becomes thin, and appropriate air diffusion cannot be performed. .

  FIG. 2 is a cross-sectional view showing an example of the intubation tube 7. The inner insertion tube 7 has an upper end connected to the diffuser plate 4, and a lower end is inserted so as to extend to the vicinity of the bottom surface in the air supply pipe 3 for diffusion, and has an inclined suction surface 8 at the lower end. ing.

  The internal intubation 7 is a supply path to the air diffusion plate 4 and has a function of discharging the supplied blow water from the diffusion plate 4 during the water blowing process.

  The inner intubation 7 may be formed integrally with the air supply pipe 3 for diffusing or may be a separate member that can be attached and detached. When it is set as another member which can be attached or detached, the inner intubation tube 7 can be inserted and fixed in the insertion port previously provided in the air supply piping 3 for aeration. There is no restriction | limiting in particular in the fixing method of the intubation tube 7, All fixing methods are included. For example, the fixing tightening member 10 is pre-welded to the side surface of the intubation tube, and the mounting bracket 11 is pre-welded to the air supply piping side, thereby screwing the internal insertion tube 7 into the air supply piping 3 for the air diffusion. Can be fixed to. Similarly, the diffuser plate 4 can be attached to and detached from the inner intubation 7. Moreover, there is no restriction | limiting in particular in the material of the intubation tube 7, Preferably, it forms from metals, such as plastic or stainless steel, titanium.

The lower end portion of the inner intubation 7 has a suction surface 8. A plurality of diffuser plates 4 are installed in the diffuser supply pipe 3, but the diffuser supply pipe 3 is not necessarily installed horizontally, and the lower end of the intubation pipe 7 is the water surface. May not be arranged at the same height. As shown in FIG. 3, when the suction surface 8 at the lower end of the intubation tube is not inclined, suction or push-up occurs only from the inner intubation tube 7 that is in contact with the water surface or under the water surface. Blow water is not uniformly supplied to the air plate 4, and there is a possibility that clogging may proceed with some diffuser plates to which no blow water is supplied.
On the other hand, as shown in FIG. 4, when the suction surface 8 at the lower end of the intubation tube is inclined, the blow water can be sucked up if the water surface is between the upper end and the lower end of the suction surface 8. Even if the lower end of the intubation is arranged up and down, it can be sucked up from all the inner intubations within a certain range, and uniform blow to the diffuser plate 4 is possible. Therefore, when the suction surface 8 is inclined, the allowable range of the installation accuracy in the horizontal direction of the air supply pipe 3 for air diffusion becomes large.

  As shown in FIG. 4, when the water level is between the upper end and the lower end of the suction surface 8, the air / water mixed phase is blown at a high blow speed, but the water level is higher than the suction surface 8 as shown in FIG. In this case, since only water is pushed up, the water extrusion blow does not mix the air.

The lower end of the inclined suction surface 8 is located in the vicinity of the inner bottom of the air supply pipe 3 for air diffusion so that even if the water level is low, the blow water can be surely sucked up or pushed up into the inner intubation tube 7. . The lower end of the inclined suction surface 8 is preferably 0 to 10 mm above the inner bottom of the air supply pipe 3 for air diffusion.
Although there is no particular limitation on the inclination angle θ of the inclined suction surface 8 with respect to the vertical direction, since the intubation tube 7 is also an air supply path, the inclination angle θ is such that air can be sufficiently supplied into the intubation tube 7. It is preferable. The inclination angle θ can be, for example, 10 to 85 degrees, preferably 30 to 80 degrees.

In the above description, an example in which a vent hole is not provided in the tube wall of the intubation tube 7 is shown. However, if there is a vent hole in the tube wall, the chemical solution is removed from the vent hole during cleaning of the diffuser plate with the chemical solution. This is because the chemical liquid is not supplied to the diffuser plate 4 side. This is because the supply efficiency of the is deteriorated.
However, even if there is a vent hole in the tube wall of the inner tube 7, it is only necessary to put the chemical solution so as to be higher than the height of the vent hole when cleaning the diffuser plate with the chemical solution. It does not exclude the provision of ventilation holes in the wall.

<Blow water supply means>
The blow water supply means 5 is a device for supplying blow water to the air supply pipe 3 through the blow water supply pipe 17 for overcoming the air pressure of the air supply pipe 3 to diffuse the blow water. The air supply pipe 3 can be supplied. As the blow water supply means 5, for example, a storage tank that stores water or the like is provided with a water supply pump that sends out water or the like stored in the storage tank.
The blow water supplied from the blow water supply means 5 flows into the air supply pipe 3 through the blow water supply pipe 17 and is sent from the air supply pipe 3 to the air diffuser plate 4 through the inner tube 7. Like air, the air is emitted from a plurality of air holes scattered on the air diffusion surface of the air diffusion plate 4.

<Chemical liquid injection device>
The chemical liquid injector 14 is an apparatus that injects an alkaline liquid into the air supply pipe 3 for diffusion through the chemical liquid injector 13. The chemical liquid injector 14 includes a storage tank that stores the alkaline liquid and a liquid feed pump that sends the alkaline liquid in the storage tank to the chemical liquid injection pipe 13.

<Pressurized air supply device>
The pressurized air supply device 16 is a device that injects pressurized air into the air supply pipe 3 for air diffusion through the air injection pipe 15 and is constituted by, for example, an air pump.

The operation of the air diffuser 1 according to the present embodiment configured as described above will be described separately for the air diffuser operation, the water blow operation, and the cleaning with the chemical solution.
<Aeration operation>
In the aeration operation, air blown from the gas supply means 2 is sent to the aeration supply pipe 3, and this air is introduced into the aeration tank 12 from the fine holes or slits of the diffusion plate 4 through the inner tube 7. The operation is to discharge as fine bubbles. During the aeration operation, the on-off valve 18 is opened and the on-off valves 19, 20, 21 are closed for operation.

<Water blow operation>
In the water blow operation, the blow water is periodically supplied from the blow water supply means 5 to the air supply pipe 3 for air diffusion, and the blow water is supplied to the air diffuser plate 4 via the inner intubation 7 to thereby diffuse the air diffuser plate. In this operation, water 4 is blown to prevent microorganisms and the like from adhering to the diffuser holes of the diffuser plate 4. There is no particular limitation on the supply frequency of the blow water, but preferably the blow water is supplied into the air supply pipe 3 for aeration every several hours to several days.
In the water blow operation, the on-off valves 18 and 21 are opened and the on-off valves 19 and 20 are closed.

<Cleaning with chemicals>
If the aeration operation is continued for a long time, even if the blow water is regularly supplied, the biofilm adheres to the diffusion plate 4 and the pressure loss in the diffusion plate 4 increases. Sometimes. In such a case, cleaning with a chemical solution is performed using a chemical solution capable of decomposing a biofilm or the like.
6 and 7 are explanatory diagrams of a cleaning method using a chemical solution in the present embodiment. Hereinafter, a cleaning method using a chemical solution will be described with reference to FIG. 1, FIG. 6, and FIG. 6 and 7, the on-off valves 18, 19, 20, and 21 are displayed in white when the valve is open, and are displayed in black when the valve is closed.

In the case of performing chemical cleaning from the state where the aeration operation is performed (see FIG. 6A), the on-off valve 18 is closed to stop the air supply for the aeration, and the on-off valve 19 is turned on in this state. Opened and injects a predetermined amount (for example, about half the height of the header pipe) of the alkali liquid from the chemical liquid injection device 14 into the air supply pipe 3 for diffusion through the chemical liquid injection pipe 13 (see FIG. 6B). ).
After closing the on-off valve 18, the air diffusion is continued until the pressure in the air supply pipe 3 becomes the same as the water pressure acting on the air diffuser plate 4. However, since the water pressure and the pressure in the air supply pipe 3 are balanced at this time, the sewage does not flow backward from the air diffuser plate 4. Absent.
The alkaline liquid injected into the air supply piping 3 is stored in the air supply piping 3 (header) as shown in FIG. 6B.

Next, the on-off valve 19 is closed to stop the injection of the chemical solution, and then the on-off valve 20 is opened to supply pressurized air to the air supply pipe 3 for air diffusion through the air injection pipe 15 (for example, 30 minutes to several hours) Inject continuously in small portions (see FIG. 6C). By injecting the pressurized air into the air supply pipe 3 for air diffusion, the pressure in the air supply pipe 3 for air diffusion gradually rises, and as shown in FIG. It is pushed up and slowly supplied to the diffuser plate 4. Thereby, the biofilm adhering to the diffuser plate 4 is decomposed by alkali.
The amount of pressurized air to be injected is preferably such that the alkaline liquid is slowly (slowly) supplied to the diffuser plate 4, for example, 0.01 L / min per diffuser plate. To do.

After injecting the pressurized air for a predetermined time, the on-off valve 20 is closed, the on-off valve 18 is opened, and air for air diffusion is supplied to the air supply pipe 3 for air diffusion. Further, the release valve 21 is opened, and blow water is supplied to the air supply pipe 3 for aeration through the blow water supply pipe 17 (see FIG. 7D). Thereby, blow water is supplied to the diffuser plate 4 together with the air for aeration, and the biofilm and the alkaline liquid remaining on the diffuser plate 4 are blown.
Thereafter, the on-off valve 21 is closed and the aeration operation is continued (see FIG. 7E). As a result, clogging is eliminated and pressure loss due to clogging is recovered.

  As described above, the air diffuser 1 according to the present embodiment includes the inner tube 7, and blow water is supplied to the air diffuser plate 4 without filling the air diffuser air supply tube 3 (header tube) with water. Since the air can be supplied, the air supply passage is always secured. Accordingly, it is possible to continuously operate the air diffuser 1 while supplying blow water periodically during the air supply and removing the microorganisms adhering to the air diffuser holes of the air diffuser plate 4 with the blow water.

Further, in the present embodiment, after the supply of air to the air supply pipe 3 for air diffusion is stopped, a predetermined amount of alkaline liquid is supplied into the air supply pipe 3 for air diffusion, and then the inside of the air supply pipe 3 for air diffusion Since the pressurized air is continuously supplied to the air diffuser for a predetermined time (for example, 30 minutes to several hours), the alkaline liquid can be continuously supplied to the diffuser plate 4 for a predetermined time (for example, 30 minutes to several hours). The clogging of the diffuser plate 4 can be effectively recovered by chemically decomposing the biofilm attached to the diffuser plate 4.
In addition, in the present embodiment, it is not necessary to fill the air supply pipe 3 (header pipe) for aeration, and it is only necessary to supply the alkali liquid in an amount necessary for cleaning the air diffuser plate 4 and waste the alkali liquid. Therefore, there is little concern about the adverse effect on activated sludge.

  In the above embodiment, the blow water is not particularly limited. However, the use of blow water containing a component having an effect of killing microorganisms can effectively suppress the growth of microorganisms. . The component having an effect of killing microorganisms is not particularly limited, but for example, an antibacterial substance or an oxidizing substance, more specifically, sodium hypochlorite, inverse soap, acid, alkali, ozone, or chlorine dioxide And alkali metal carbonates.

  A diffuser plate having the following specifications was installed in the aeration tank 12, and water blowing was performed under the following conditions to confirm the effect of water blowing.

Air diffuser material: SUS316L
Hole shape: Length 1.45mm, width 0.04mm
Opening ratio: about 0.5%
Air flow: 30m3 / m2 / hr
Blow water: Sodium hypochlorite solution (concentration: 100 ppm)
Blow water amount: 500 ml / time Water blow frequency: 1 time / day An example in which no water blow was performed was used as a comparative example.

  The graph of FIG. 8 shows the change over time in the amount of increase in pressure loss (mmAq) in the example (Example) with and without water blow (Comparative Example).

  As is clear from the graph of FIG. 8, by periodically carrying out the water blow, it is possible to effectively suppress an increase in the pressure loss of the air diffuser even in the air diffused operation over a long period of time, and to achieve a high oxygen transfer efficiency. Could be maintained.

In order to confirm the effect of chemical cleaning, the following three types of experiments were conducted.
<Experimental example 1>
As shown in FIG. 9, a diffuser block having 24 diffuser plates 4 installed on the header pipe 22 is arranged at a water depth of 1 m in the aeration tank, and 1.5 m ³ / hr (per diffuser plate) ( (30 m ³ / m ² / hr) was continuously aerated.
The pressure loss of the diffuser plate 4 at the start of aeration was 236 mmAq.
It was 441 mmAq when the pressure loss of the diffuser plate 4 when 300 days passed after the start of aeration was measured.
Therefore, chemical cleaning was performed by the following method.
The on-off valve 23 at the inlet of the header pipe was closed, and 45 L of 5% NaOH solution was poured into the header pipe 22 having a total volume of 80 L as a chemical solution while maintaining the pipe internal pressure at a positive pressure relative to the water pressure. After injecting the chemical solution, air was supplied into the header pipe 22 using an air pump, and the injected chemical solution was supplied to the diffuser plate 4 through the inner tube 7 (see FIG. 1) while being extruded with air. The air supply rate was 220 ml / min, and the supply was continued for 3 hours.
After finishing the chemical solution extrusion by air, 48 L of filtered water was supplied into the header pipe 22, the on-off valve was opened, blower air was introduced into the header pipe 22, and water was blown into the diffuser plate 4.
When the pressure loss of the diffuser plate 4 was measured 30 minutes after the completion of the water blow, it was 254 mmAq, and the recovery rate of the pressure loss was 91.2%.
Thus, it was confirmed that effective cleaning of the diffuser plate 4 can be performed by performing chemical cleaning with an alkaline solution.

<Experimental example 2>
Under the same conditions as in Experimental Example 1, a similar experimental example was performed in which the chemical solution was 5% NaOH + 2% sodium carbonate. The pressure loss after chemical cleaning was measured and found to be 244 mmAq. The recovery rate of pressure loss was 96.1%.
Thus, it was confirmed that the washing effect was further improved by adding sodium carbonate to sodium hydroxide as an alkali.

<Experimental example 3>
After the completion of the extrusion of alkaline chemical solution in Experimental Example 1, 5% oxalic acid was injected into the 45 L header tube as an acidic chemical, and the acidic chemical solution was extruded with air in the same manner as in Experimental Example 1, and then the same water blow as in Experimental Example 1 was performed. Carried out. The pressure loss after chemical cleaning was measured and found to be 238 mmAq. The recovery rate of pressure loss was 99.0%.
As described above, it was confirmed that, for example, mineral-based soil that cannot be cleaned by alkali cleaning can be effectively cleaned by performing cleaning with acid after alkali cleaning.
The pressure loss measurement results shown in Experimental Examples 1 to 3 are summarized in Table 1 below.

It is a mimetic diagram of an air diffuser concerning one embodiment of the present invention. It is sectional drawing of the intubation which concerns on one embodiment of this invention. It is a figure which shows the one aspect | mode of the intubation tube which concerns on one embodiment of this invention, and is a schematic diagram in case the suction surface is not inclined. It is a figure which shows the other aspect of the intubation tube which concerns on one embodiment of this invention, and is a schematic diagram in case the suction surface inclines. It is explanatory drawing of the effect | action of the intubation in one embodiment of this invention. It is explanatory drawing of the washing | cleaning method by the chemical | medical solution in one embodiment of this invention. It is explanatory drawing of the washing | cleaning method by the chemical | medical solution in one embodiment of this invention. 3 is a graph showing the change over time in the amount of increase in pressure loss in Example 1. 6 is an explanatory diagram of an experimental example of Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air diffuser 2 Gas supply means 3 Air supply piping for aeration 4 Air diffuser plate 5 Blow water supply means 7 Inner intubation 8 Suction surface 9 Vent 10 Fixing member 11 Mounting bracket 12 Aeration tank 13 Chemical solution injection pipe 14 Chemical solution Injection device 15 Air injection pipe 16 Pressurized air supply device 17 Blow water supply pipe 18, 19, 20, 21, 23 On-off valve 22 Header pipe θ Inclination angle

Claims (4)

A diffuser plate having fine pores installed in the aeration tank, a diffuser air supply pipe connected to the diffuser plate, and the diffuser connected to the diffuser air supply pipe via an open / close valve An air supply comprising an air supply device for supplying air for diffusion to an air supply pipe, and an intubation pipe having one end connected to the air diffuser plate and the other end inserted into the air supply pipe for air diffusion A method for cleaning an apparatus,
A pressurized air supply device for injecting pressurized air into the air supply pipe for air diffusion, and a chemical liquid injection device for injecting a cleaning chemical into the air supply pipe for air diffusion,
After stopping the supply of the air diffuser for air to air air supply piping scattered by closing the on-off valve, the cleaning agent liquid supply for supplying a cleaning agent liquid feeding to sign tube for the air diffuser by the liquid injector a step, and continuously supplied to the pressurized air supply device by said air diffuser for supply to the sign tube pressurized air 30 minutes to several hours, through the intubation cleaning agent liquid of the air diffuser for supply quotations tube A method for cleaning an air diffuser comprising a chemical cleaning process for an air diffuser that continuously discharges from an air diffuser. Provided blow water supply means for supplying blow water supply quotations tube for aeration, after washing with the washing agent solution, air diffuser for feeding signs supplies blow water supply quotations tube for air diffuser by said blowing water supplier The air diffuser according to claim 1, further comprising a water blowing step for blowing air into the pipe and supplying the blow water to the diffuser plate through an intubation tube to blow the water. Cleaning method. Irrigant fluid, the cleaning method of the air diffuser device according to claim 1 or 2, characterized in that a chemical solution composed mainly of an alkali. Method of cleaning an air diffuser apparatus according to claim 3, irrigant fluid, characterized in that it contains sodium carbonate.

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