JP4426596B2 - Air diffuser - Google Patents

Description

  The present invention relates to an apparatus that diffuses air into water to be treated contained in an aeration tank or the like.

Conventionally, when biological treatment is performed on water to be treated in an activated sludge tank, aeration treatment is performed in which air is diffused and aerated in the water to be treated in order to supply oxygen to microorganisms. The following are mainly used as the air diffuser.
(1) A plate made of porous ceramic (a diffuser plate) is fixed to the upper surface of a concrete or synthetic resin holder (a container with an open top surface), and air is pressed into the holder to diffuse the diffuser plate. To generate bubbles by passing through;
(2) A branch pipe from the air main pipe is connected to the hollow part of a porous ceramic molded hollow cylinder (spread cylinder), and air is injected into the hollow part of the dust cylinder and passes through the wall of the dust cylinder. To generate bubbles by
(3) Covering the opening of the holder with a circular rubber such as neoprene rubber, fixing the center of the holder, and injecting air into the holder to vibrate the peripheral end of the circular rubber to generate bubbles.

  Among the air diffusers (1) to (3), in the device (3), the generated bubbles are large, and the efficiency of dissolving oxygen in the water to be treated is insufficient. Therefore, it is difficult to say that it is suitable for the main aeration and is mainly used for preliminary aeration.

  In contrast, in the case of the devices (1) and (2), although relatively fine bubbles can be generated, suspended solids in the water to be treated when the device is stopped due to a power failure or periodic inspection. Has the disadvantage of causing sedimentation and clogging of the diffuser holes.

Under such a background, use of a diffuser panel type diffuser has been studied (Patent Document 1, etc.). In this device, a diffused panel in which a synthetic resin film is molded into a sheet shape is placed on the upper surface of the holder. The diffused panel expands due to the pressure of the air press-fitted into the holder, creating diffused holes, and the air The fine bubbles can be supplied into the treated water by passing through. Further, when the supply of air is stopped, the diffuser panel returns to a smooth sheet shape, so that the diffuser holes apparently disappear. Therefore, when the apparatus is stopped, it is possible to prevent clogging of the air holes due to sedimentation of suspended solids in the water to be treated.
JP-T-2001-504754

  However, even with the diffuser panel diffuser, the diffuser holes of the diffuser panel may be clogged during operation of the apparatus. For example, when air is diffused into the treated water contained in the activated sludge tank of the sewage treatment plant, the pressure loss of the diffused panel increases in about 1 to 2 days, and the oxygen supply to the treated water becomes normal. It becomes impossible to do.

  When the air diffusion holes are clogged in this way, normal operation can be restored by stopping the air supply and returning the air diffusion panel to a smooth sheet, and then supplying air again. This is considered to be due to the clogging material being blown out of the air holes by the contraction of the air diffuser panel when the air diffuser panel returns to a smooth sheet shape. However, frequent or prolonged blow-down should be avoided as much as possible in biological treatment.

  The present invention has been made in view of the above-described problems of the prior art. When air is diffused into water to be treated, fine bubbles can be stably supplied over a long period of time without causing clogging of the diffused holes. It is an object of the present invention to provide an air diffusion method and apparatus capable of achieving sufficient oxygen dissolution efficiency for biological treatment and the like.

In order to solve the above-mentioned problem, the aeration method of the present invention is a method of aerating air into treated water containing organic waste water and biological sludge,
Humidified air is supplied from one side of the diffused panel made of a synthetic resin film formed into a sheet shape to the other side, and air is blown out in a humidified state from the diffused holes generated by the expansion of the diffused panel. It is characterized by generating fine bubbles in the treated water.

Further, the air diffuser of the present invention is an apparatus that diffuses air into the water to be treated containing organic waste water and biological sludge,
Air blowing means for supplying air;
A humidifying means connected to the blowing means via the flow path, and humidifying the air from the blowing means;
A diffuser panel made of a synthetic resin film formed into a sheet shape is provided, air from the humidifying means is supplied from one surface of the diffuser panel to the other surface, and from the diffuser holes generated by the expansion of the diffuser panel It is characterized by comprising an air diffuser that spouts air in a humidified state to generate fine bubbles in the water to be treated.

  In the present invention, air that has been humidified is pressed into an air diffuser disposed soaked in the water to be treated, and air is ejected in a humidified state from the air diffuser generated by the expansion of the air diffuser panel. Since it is generated in the water to be treated, a sufficient amount of oxygen for biological treatment can be dissolved in the water to be treated. At this time, since the hole diameter of the air diffusion holes is smaller than those of the conventional examples (1) to (3), the precipitates caused by the suspended solids or dissolved substances in the water to be treated are clogged when adhering to the air diffusion holes. Although it is likely to occur, in the present invention, by blowing out air in a humidified state, adhesion of suspended solids and precipitation of dissolved substances are less likely to occur, and even when these adhere or precipitate, the water vapor in the air is effective. It can be removed well and reliably. Therefore, according to the present invention, an air diffusion method and apparatus capable of stably supplying fine bubbles over a long period of time without causing a clogging phenomenon of air diffusion holes and achieving sufficient oxygen dissolution efficiency are realized. .

  Further, the air diffusion method of the present invention may be characterized in that the relative humidity of the humidified air is 70% or more at the temperature of the water to be treated. Thereby, the removal efficiency of the adhering substance from an air diffusion hole can be improved.

  Further, in the air diffuser of the present invention, the air diffuser includes a plate-shaped metal plate, and an air diffuser panel in which a synthetic resin film formed into a sheet shape is disposed so as to cover one surface of the plate, An air inlet provided at a predetermined position of the plate or the diffuser panel and introducing air from the humidifying means between the plate and the diffuser panel may be provided. As a result, an air diffuser having excellent characteristics of stably supplying fine bubbles over a long period of time without causing a clogging phenomenon of the air diffused holes and achieving sufficient oxygen dissolution efficiency is realized.

  In the air diffuser of the present invention, the air diffuser includes a container having an open top surface, an air diffuser panel in which a synthetic resin film formed in a sheet shape is disposed so as to cover the top surface of the container, and the container or the diffuser. An air inlet provided at a predetermined position of the air panel and for introducing air from the humidifying means into the container may be provided. As a result, an air diffuser having excellent characteristics of stably supplying fine bubbles over a long period of time without causing a clogging phenomenon of the air diffused holes and achieving sufficient oxygen dissolution efficiency is realized.

Further, the air diffuser of the present invention comprises a temperature measuring means for measuring the temperature of the water to be treated and the temperature of the air supplied to the humidifying means,
Control means for controlling the humidification means so that the relative humidity of the air is 70% or more at the temperature of the water to be treated may be further provided. As a result, an air diffusing device in which the efficiency of removing adhered substances from the air diffusing holes is further improved is realized.

Further, the air diffuser of the present invention comprises a measuring means for measuring the temperature and humidity of the air supplied to the blowing means, and the temperature, air volume and pressure of the air supplied from the blowing means to the humidifying means,
Measured values of the temperature and humidity of the air supplied to the blowing means obtained by the measuring means and electrically measured with the humidifying means, and measured values of the temperature, air volume and pressure of the air supplied from the blowing means to the humidifying means And a control means for controlling the relative humidity of the air in the humidifying means. As a result, it becomes possible to stably supply sufficiently humidified air to the air diffuser, and the above-described effects can be further enhanced.

Further, the air diffuser of the present invention comprises a measuring means for measuring the temperature, humidity, air volume and pressure of the air supplied from the blowing means to the humidifying means,
It is electrically connected to the humidifying means and controls the relative humidity of the air in the humidifying means based on the measured values of temperature, humidity, air volume and pressure of the air supplied from the blowing means obtained by the measuring means to the humidifying means. Control means may further be provided. Also with such an air diffuser, it becomes possible to stably supply sufficiently humidified air to the air diffuser, and the above-described effects can be further enhanced.

  As described above, in the present invention, by pressing the humidified air into the air diffuser disposed immersed in the water to be treated, and blowing the air in a humidified state from the air diffuser generated by the expansion of the air diffuser panel, Since fine bubbles are generated in the water to be treated, a sufficient amount of oxygen for biological treatment or the like can be dissolved in the water to be treated. At this time, the suspended solids in the water to be treated or precipitates resulting from the dissolved matter are less likely to adhere to the diffuser holes, and even if these substances adhere to the diffuser holes, they are efficiently removed by water vapor in the air. It can be removed well and reliably. Therefore, according to the present invention, an air diffusion method and apparatus capable of stably supplying fine bubbles over a long period of time without causing a clogging phenomenon of air diffusion holes and achieving sufficient oxygen dissolution efficiency are realized. .

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the dimensional ratios in the drawings do not necessarily match those described.

  FIG. 1 is a schematic configuration diagram showing an air diffuser according to a first embodiment of the present invention. In the figure, the aeration tank 1 contains treated water 10 containing organic drainage and activated sludge, and the middle layer of the aeration tank 1 is brought to one side of the opposing inner wall of the aeration tank 1. Aeration means 2 is provided.

  FIG. 2 is a cross-sectional view schematically showing a schematic configuration of the air diffuser 2. In FIG. 2, the air diffuser 2 includes a plate-shaped metal plate 2a and an air diffuser panel 2b arranged so as to cover one surface of the plate 2a with a synthetic resin film formed into a sheet shape. Has been. A plastic cover 21 having a fitting portion 21a and a communication portion 21b formed in a concave shape around the fitting portion 21a is provided at the peripheral edge of the plate 2a, and the diffuser panel 2b is connected to the communication portion 21b. The plate 2a and the diffuser panel 2b are integrated by connecting the peripheral edge portion so as to be folded back from the upper surface to the lower surface of the plate 2a and by fitting the peripheral portion of the fitting portion 2 and the plate 2a. . Furthermore, these are firmly fixed by the SUS cover 22 which sandwiches the plastic cover from the upper and lower surfaces of the plate 2a.

  Moreover, the opening part 23 is provided in the predetermined position of the diffuser panel 2b, and the piping 24 is inserted in the opening part 23, and the air inlet 2c is formed. Inside the diffuser panel 2 b, a packing 25 and a rubber seal 26 made of the same material as the diffuser panel 2 b are attached to the pipe 24, and the tip thereof is supported by a support member 27. Further, on the outside of the diffuser panel 2b, a packing 25 and a SUS packing 28 made of the same material as the diffuser panel 2b are attached to the pipe 24. By sandwiching these between the nut 29 and the support member 27, the pipe 24 is connected to the plate 2a. It is fixed to.

  The diffuser panel 2b is a smooth sheet that does not allow air to pass through when no pressure is applied from the inside of the diffuser means 2 (double-dotted line in FIG. 1), but when air is injected from the air inlet 2c, It expands to produce a plurality of pores (aeration holes) (solid line in FIG. 1). Specific examples of the synthetic resin used in the diffuser panel include a polyurethane resin.

  A flow path 3 is connected to the air introduction part 2 c of the air diffusion means 2, and a humidification means 4 and a blower (blower) 5 are provided in the flow path 3 in order from the side close to the air diffusion means 2. Yes. The blower 5 is for supplying air to the air diffuser 2. The air supply amount is set so that the pressure in the air diffuser 2 is 0.1 to 0.2 kPa larger than the pressure corresponding to the water depth at the position where the air diffuser 2 is installed.

  The air from the blower 5 is humidified by the humidifying means 4 and then press-fitted into the diffuser means 2 from the air inlet 2c. The humidifying method in the humidifying means 5 is not particularly limited, and examples thereof include a method in which spray water or steam is directly mixed into the air, a method in which aeration air is introduced into the packed tower in advance, and the like.

  The aeration tank 1 is provided with a temperature measuring means 7, and a temperature / humidity measuring means 8 is provided on the outlet side of the humidifying means 4. The temperature measuring means 7, the temperature / humidity measuring means 8 and the humidifying means 4 are control means. 9 is electrically connected. As a result, measurement data signals relating to the temperature of the water to be treated 10 and the temperature and humidity of the air supplied from the humidifying means 4 to the diffuser means 2 are sent from the temperature measuring means 7 and the temperature / humidity measuring means 8 to the control means 9. Furthermore, a control signal for controlling the humidification condition of the air is sent from the control means 9 to the humidification means 4 based on the obtained measurement value. Thereby, the humidification conditions of the air in the humidification means 4 can be controlled so that the relative humidity at the temperature of the water to be treated 10 becomes a predetermined value.

  A procedure when air is diffused into the water to be treated using the air diffuser having the above configuration will be described with reference to FIG. FIG. 3 is an explanatory diagram conceptually showing a state when air diffusion holes are generated by the expansion of the air diffusion panel 2b. In the present embodiment, after the air from the blower 5 is humidified by the humidifying means 4 and then press-fitted into the air diffuser 2 from the air inlet 2c, the air diffuser panel 2b expands in the direction of the arrow due to the air pressure. As a result, minute diffused holes 2d (pores with a pore diameter of preferably 0.1 to 0.3 mm) are formed in the diffuser panel 2b. And the fine bubble 100 generate | occur | produces in the to-be-processed water 10 when air blows off from the diffuser hole 2d in a humidified state. At this time, since the aeration means 2 is arranged close to one side of the opposing inner wall in the aeration tank 1 as described above, the generated fine bubbles 100 are treated with the water to be treated as indicated by the arrows in FIG. Cycle in the direction. In this way, a sufficient amount of oxygen can be dissolved in the water to be treated.

  Moreover, although there are adhering substances such as suspended solids and dissolved substances contained in the water to be treated 10, even when these adhere to the diffuser holes, the humidified air is diffused. It can be efficiently and reliably removed by water vapor in the air when passing through. Therefore, according to the present embodiment, it is possible to stably supply fine bubbles over a long period of time without causing the clogging phenomenon of the diffused holes, and to achieve sufficient oxygen dissolution efficiency.

  Here, when the air is humidified, the relative humidity is controlled to be 70% or more (more preferably 90% or more, more preferably a saturated or supersaturated state of water vapor) at the temperature of the water to be treated. It is preferable. By humidifying the air so that the relative humidity satisfies the above condition, the removal efficiency of the adhering substances from the air diffusion holes 2d can be increased.

  In biological treatment, the temperature of the water to be treated 10 is usually relatively low at 15 to 25 ° C., while the temperature of the air supplied to the humidifying means 4 is higher than the temperature of the water to be treated 10 due to pressurization. It tends to be expensive. At this time, when the air is humidified to a saturated state or a supersaturated state at the temperature on the inlet side of the humidifying means 4, a phenomenon that water generated by the cooling of the air is likely to stay in the aeration means 2 or the flow path 3 is likely to occur. As described above, the air is humidified so that the relative humidity at the temperature of the water to be treated satisfies a predetermined condition, thereby preventing the water from staying in the apparatus even when the temperature of the water to be treated is low. Can do.

  Further, in the case of the apparatus shown in FIG. 1, when the operation of the apparatus is stopped due to a power failure or periodic inspection, the diffuser panel 2b becomes a smooth sheet, and the diffuser holes seem to disappear (see two in FIG. 1). Dotted line). As a result, even if suspended solids contained in the water to be treated 10 adhere to and accumulate on the diffuser panel 2b, they cannot be a cause of clogging of the diffuser holes.

  FIG. 4 is a schematic configuration diagram showing a second embodiment according to the air diffusing device of the present invention. In the air diffuser shown in FIG. 4, the air diffuser 2 has a diffuser formed by forming the opening of a stainless steel container (holder) 2e having a bottom surface and four side surfaces and an open top surface into a synthetic resin film sheet shape. FIG. 1 shows that it is covered with an air panel 2b and the peripheral portion of the diffuser panel 2b is fixed to the holder 2e to form a sealed structure, and that an air introduction part 2c is provided on the bottom surface of the holder 2e. The other configuration is the same as that of the apparatus shown in FIG.

  The air diffuser shown in FIG. 4 is different from the device shown in FIG. 1 only in a part of the constituent members of the air diffuser 2, and the mechanism when air is diffused into the treated water is shown in FIG. This is the same as the case of the apparatus. That is, also in the apparatus shown in FIG. 4, after the air from the blower 5 is humidified by the humidifying means 4, it is pressed into the air diffuser 2 from the air inlet 2 c, and the air diffuser panel 2 b is indicated by the arrow by the air pressure. Inflates in the direction. Along with the expansion of the diffuser panel 2b, minute diffuser holes 2d are formed in the diffuser panel 2b, and air is ejected from the diffuser holes 2d in a humidified state, whereby fine bubbles 100 are generated in the treated water 10. Therefore, according to the second embodiment as well, it is possible to stably supply fine bubbles over a long period of time without causing the clogging phenomenon of the diffused holes, and to achieve sufficient oxygen dissolution efficiency.

  Furthermore, in the present invention, the humidity of the air supplied from the humidifying means to the air diffuser is more reliably controlled by using specific measuring means and control means as in the third and fourth embodiments described later. Further, the effect of preventing clogging of the air diffuser can be further enhanced.

  FIG. 5 is a schematic configuration diagram showing an air diffuser according to a third embodiment of the present invention. In FIG. 5, the flow path 3 includes a header pipe 11, and a blower 5 is provided on the upstream side of the header pipe 11. Further, the suction side temperature measuring means 13 and the suction side humidity measuring means 14 are provided in the air suction pipe 12 of the blower 5, and the pressure side temperature measurement is provided between the blower 5 and the header pipe 11 in the flow path 3 (pneumatic feed side). Means 15, air volume measuring means 16 and pressure measuring means 17 are provided. Further, a water spray pump 18 is connected to the header pipe 11 via a flow path 19. The suction side temperature measuring means 13, the suction side humidity measuring means 14, the pumping side temperature measuring means 15, the air volume measuring means 16, the pressure measuring means 17 and the watering pump 18 are each electrically connected to the control means 9.

  In the apparatus shown in FIG. 5, the humidifying means 4 is configured by connecting the watering pump 18 and the header pipe 4 via the flow path 19 in this way. At this time, the temperature and humidity of the air sucked into the blower 5 are measured by the suction-side temperature measuring means 13 and the suction-side humidity measuring means 14, and the temperature, the air volume and the air pressure fed from the blower 5 to the header pipe 11 are measured. After the pressure is measured by the pressure side temperature measuring means 15, the air volume measuring means 16, and the pressure measuring means 17, a data signal for each obtained measurement value is sent to the control means 9. Based on these data signals, a control signal relating to the amount of water supplied from the control means 9 to the watering pump 18 is sent, and a predetermined amount of water is sprayed in the header pipe 11.

Here, a specific procedure for controlling the amount of sprinkling based on the above measured value will be described with reference to FIG. 6, taking as an example the case where the temperature of the air sucked into the blower 5 is 20 ° C. and the relative humidity is 60%. To do. FIG. 6 shows a low temperature humidity table. Curves l ₁ and l ₂ represent temperature (unit: ° C.) and relative humidity (relative humidity, unit: kg-water vapor / kg-) when the humidity is 100% and 60%, respectively. Correlation with dry air).

  The state of air sucked by the blower 5 at a temperature of 20 ° C. and a relative humidity of 60% corresponds to a point A in FIG. Since this air is pumped by the blower 5, after the outlet of the blower 5, the temperature of the air rises due to pressurization, and the relative humidity is lowered accordingly (point B in FIG. 6).

Humidifying the air in the state of point B to 100% relative humidity changes the state to the intersection C of the adiabatic cooling line l ₃ passing through point B in FIG. 6 and the curve l ₁ indicating 100% relative humidity. It corresponds to that. Accordingly, the control means 9 performs arithmetic processing based on the measured values of the air temperature and humidity at the point A and the air temperature, pressure and air volume at the point B, and the dispersion necessary for obtaining the state of the point C is performed. The amount of water is calculated. In such calculation processing, it is possible to apply the following equation (2) corrected by pressure, which is derived by solving the following equation (1) representing the relative humidity in the case of mass reference.

[In formula (1), Y represents the relative humidity, M _V and M _G represent respectively the molar mass of water vapor and air, p and p _V represents the total pressure and water vapor partial pressure, respectively]

Wherein _{(2), M V, M} G and p are the same as M _V, M _G and p in the formula (1), Y _S represents the relative humidity in the pressure p, Y ₁ is 1 atm ( 101.325 kPa) relative humidity. ]

  In the apparatus shown in FIG. 5, the humidifying means is configured by connecting the watering pump 18 and the header pipe 4 via the flow path 19 as described above. In FIG. 2, a part of the configuration of the humidifying means is omitted. Hereinafter, the configuration of the humidifying means will be described in detail with reference to FIG. For convenience, FIG. 7 does not show the blower 5 on the upstream side of the header pipe 11, the measurement means 13 to 17, and the aeration tank 1 and the air diffusion means 2 on the downstream side of the header pipe 11.

  As shown in FIG. 7, the header pipe 11 is connected with a makeup water introduction flow path 201 for introducing water into the pipe. A purification means 200 (ion exchanger, membrane filter, etc.) and a makeup water control valve 202 are provided in the makeup water introduction flow path 201 in order from the upstream side, and the makeup water control valve 202 measures the water level in the header pipe 11. The water level measuring means 203 is electrically connected. As a result, a data signal based on the water level of the header pipe 11 is sent from the water level measuring means 203 to the makeup water control valve 202, the opening of the makeup water control valve 202 is adjusted, and the water level in the header pipe 11 is controlled.

  The header pipe 11 is connected to a circulation flow path 19 that draws makeup water collected at the bottom of the pipe and supplies it to the shower nozzle 204 at the top of the pipe. The circulation channel 19 is provided with a water spray pump 18 and a spray water control valve 205 in order from the upstream side, and the spray water control valve 205 is electrically connected to the control means 9. Thereby, a control signal based on the data signal from the measuring means 13 to 17 (not shown) is sent from the control means 9 to the spray water control valve 205, and the supply amount of the spray water to the shower nozzle 204 is controlled.

  When humidifying is performed by the humidifying means shown in FIG. 7, first, tap water is purified by the purifying means 200, and the purified water (make-up water) is supplied from the make-up water control valve 202 to the bottom of the header pipe 4. At this time, the water level is measured by the water level measuring means 203, and when the predetermined water level is reached, the makeup water control valve 202 is fully closed. When the supply of makeup water is stopped, the watering pump is operated, spray water is supplied from the shower nozzle at the top of the header pipe 11, and the pressurized air in the header pipe 11 is humidified. At this time, the opening degree of the spray water control valve 11 is adjusted by the control signal from the control means 9 and controlled to the amount of spray water necessary for achieving the desired relative humidity.

  As described above, in the third embodiment, the temperature and humidity of the air supplied to the blower 5 and the temperature, air volume and pressure of the air supplied from the blower 5 to the header pipe 11 are measured, and based on these measured values. The amount of water supplied from the watering pump 18 to the header pipe 11 is controlled. Thereby, even when the air supplied from the blower 5 to the air diffuser 2 is at a high pressure or when the temperature of the air rises due to the pressure feeding by the fan 5, the sufficiently humidified air is diffused by the air diffuser. 2 can be stably supplied, and the effect of preventing the clogging of the air diffusion holes and the efficiency of dissolving oxygen in the water to be treated can be further increased. Therefore, this embodiment is particularly useful in a sewage treatment plant where a deep aeration tank having a large water depth (for example, 10 m or more) and a large capacity is used, and a plurality of aeration devices are arranged in the aeration tank to perform aeration. Useful for.

  FIG. 8 is a schematic configuration diagram showing an air diffuser according to a fourth embodiment of the present invention. The apparatus shown in FIG. 8 has the flow path 3 configured to include the header pipe 11 as in the apparatus shown in FIG. 5, and is provided between the blower 5 and the header pipe 11 in the flow path 3 (pneumatic feed). The pressure side temperature measuring means 15, the pressure side humidity measuring means 206, the air volume measuring means 16 and the pressure measuring means 17 are provided, and the pressure side temperature measuring means 15, the pressure side humidity measuring means 206, and the air volume measuring means 16 are provided. The pressure measuring means 17 is electrically connected to the control means 9. In FIG. 8, as in the case of FIG. 5, the configuration of the humidifying unit including the header pipe 11 and the watering pump 18 is partially omitted, but the humidifying unit of this embodiment is also illustrated. This has the configuration shown in FIG.

  In the present embodiment, the temperature, humidity, pressure, and air volume of the air that is pumped from the blower 5 to the header pipe 11 are respectively the pressure-side temperature measuring means 15, the pressure-side humidity measuring means 206, the air volume measuring means 16, and the pressure measuring means 17. Measured by After a data signal for each measurement value obtained in this way is sent to the control means 9 and a predetermined calculation process is performed, a control signal related to the amount of supplied water is sent from the control means 9 to the watering pump 18. A predetermined amount of water is sprayed in the header pipe 11. Thereby, even when the air supplied from the blower 5 to the air diffuser 2 is at a high pressure or when the temperature of the air rises due to the pressure feeding by the fan 5, the sufficiently humidified air is diffused by the air diffuser. 2 can be stably supplied, and the effect of preventing the clogging of the air diffusion holes and the efficiency of dissolving oxygen in the water to be treated can be further increased. Therefore, this embodiment is very useful in a sewage treatment plant where a deep layer aeration tank is used and a plurality of aeration devices are arranged in the aeration tank to perform aeration, as in the third embodiment.

  In addition, this invention is not limited to said embodiment. For example, in the above embodiment, when the temperature and humidity of the air on the outlet side of the humidifying unit 4 are relatively stable, the temperature of the water to be treated 10 obtained in advance and the outlet side of the humidifying unit 4 Based on the temperature and humidity of the air, the humidification condition may be set so that the relative humidity at the temperature of the water to be treated 10 becomes a desired value, and air diffusion may be performed.

  Moreover, in the said embodiment, although the example of an apparatus which installed the aeration means 2 in the middle layer part of the aeration tank 1 was shown, you may change the position of the aeration means 2 according to the water depth of the aeration tank 1, etc. That is, when the water depth of the aeration tank 1 is relatively deep, about 6 to 10 m, it is preferable to dispose the aeration means 2 in the middle layer of the aeration tank 1 as shown in FIG. When the water depth of the tank 1 is relatively shallow, such as less than about 6 m, it is preferable to dispose the aeration means 2 at the bottom of the aeration tank 1.

  Moreover, in the said embodiment, although the aeration means 2 is arrange | positioned near one side of the inner wall which the aeration tank 1 opposes, the generated microbubble circulates in the to-be-processed water 10, The water to be treated 10 may be agitated by agitation means including a child and a motor. Since the fine bubbles generated thereby are diffused into the water to be treated 10, it is possible to increase the efficiency of dissolving oxygen in the water 10 to be treated.

  Moreover, the number of the aeration means used in the present invention is not particularly limited. For example, a plurality of aeration means may be arranged so as to be parallel to each other in the water to be treated.

  In addition, as described above, it is preferable to use purified water obtained by an ion exchanger, a membrane filter, or the like as water used for humidifying air. However, the water for humidification should be sterilized by UV irradiation or the like. Is also preferable.

  Furthermore, in the present invention, it is also possible to improve the detergency of the air holes by adding an oxidizing agent, an acid or a base to the humidifying water. Examples of the oxidizing agent used for the humidifying water include sodium hypochlorite, chlorine, chlorine dioxide and the like. Examples of the acid and base include hydrochloric acid, sulfuric acid, nitric acid, oxalic acid, citric acid, sodium hydroxide and the like. The amount of oxidant, acid and base added can be set as appropriate according to the type of the oxidizer, but the adhering matter can be efficiently removed and will not adversely affect when discharged into the water to be treated. It is preferable to set within the range. For example, in the case of an aqueous sodium hypochlorite solution, the concentration of sodium hypochlorite is preferably 1 to 100 mg / l.

It is a schematic structure figure showing a 1st embodiment of an aeration device of the present invention. It is a schematic cross section which shows the aeration means with which the apparatus shown in FIG. 1 is provided. It is explanatory drawing which shows notionally a state when a diffused hole arises by expansion | swelling of the diffused panel which concerns on this invention. It is a schematic block diagram which shows 2nd Embodiment of the air diffusion apparatus of this invention. It is a schematic block diagram which shows 3rd Embodiment of the air diffusion apparatus of this invention. The low temperature humidity table is shown, and the curves l ₁ and l ₂ are the temperature (unit: ° C.) and relative humidity (relative humidity, unit: kg-water vapor / kg-dry air) when the humidity is 100% and 60%, respectively. ). It is a schematic block diagram which shows an example of the humidification means concerning this invention. It is a schematic block diagram which shows 4th Embodiment of the air diffusion apparatus of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Aeration tank, 2 ... Air diffuser, 2a ... Plate, 2b ... Air diffuser panel, 2c ... Air inlet, 2d ... Air diffuser hole, 2e ... Container (holder), 21 ... Plastic cover, 21a ... Fitting part, 21b ... communication part, 22 ... SUS cover, 23 ... opening, 24 ... piping, 25 ... packing, 26 ... rubber packing, 27 ... support member, 28 ... SUS packing, 29 ... nut, 3 ... flow path, 4 ... humidification Means, 5 ... Air blower, 7 ... Temperature measuring means, 8 ... Temperature / humidity measuring means, 9 ... Control means, 10 ... Water to be treated, 100 ... Fine bubbles, 200 ... Purifying means, 201 ... Supply water introduction flow path, 202 DESCRIPTION OF SYMBOLS ... Supply water control valve, 203 ... Water level measurement means, 204 ... Shower nozzle, 205 ... Spray water control valve, 206 ... Pumping side humidity measurement means.

Claims (5)

A device that diffuses air into water to be treated including organic wastewater and biological sludge,
Air blowing means for supplying air;
A humidifying means connected to the blowing means via a flow path and humidifying the air from the blowing means;
A diffuser panel formed of a synthetic resin film formed into a sheet shape, supplying air from the humidifying means from one surface of the diffuser panel to the other surface, and a diffuser generated by expansion of the diffuser panel Aeration means for generating fine bubbles in the water to be treated by jetting air from the pores in a humidified state;
Temperature measuring means for measuring the temperature of the treated water;
Measuring means for measuring the temperature, humidity, air volume and pressure of the air supplied from the blowing means to the humidifying means;
The temperature measuring means, the humidifying means, and the measuring means are electrically connected, and the temperature of the water to be treated obtained by the temperature measuring means and the air blowing means obtained by the measuring means are supplied to the humidifying means. Control for controlling the relative humidity of the air in the humidifying means based on the measured values of the temperature, humidity, air volume and pressure of the air so that the relative humidity of the air is not less than a predetermined value at the temperature of the water to be treated. Means,
An air diffusing device comprising: The measuring means is a measuring means for measuring the temperature and humidity of air supplied to the blowing means, and the temperature, air volume and pressure of air supplied from the blowing means to the humidifying means,
The control means includes a temperature of the water to be treated obtained by the temperature measuring means, a temperature and humidity of air supplied to the blowing means obtained by the measuring means, and air supplied from the blowing means to the humidifying means. Control means for controlling the relative humidity of the air in the humidifying means so that the relative humidity of the air is equal to or higher than a predetermined value at the temperature of the water to be treated based on the measured values of temperature, air volume and pressure. The air diffuser according to claim 1, characterized in that   The air diffuser includes a plate-shaped metal plate, an air diffuser panel formed by covering a synthetic resin film formed into a sheet shape so as to cover one surface of the plate, and the plate or the air diffuser panel. The air diffuser according to claim 1, further comprising: an air inlet that is provided at a predetermined position and introduces air from the humidifying means between the plate and the air diffuser panel. apparatus.   The air diffuser includes a container having an upper surface opened, an air diffuser panel in which a synthetic resin film formed in a sheet shape is disposed so as to cover the upper surface of the container, and a predetermined position of the container or the air diffuser panel. The air diffuser according to claim 1, further comprising an air inlet for introducing air from the humidifying means into the container.   5. The control unit according to claim 1, wherein the control unit is a control unit that controls the humidifying unit so that a relative humidity of the air is 70% or more at a temperature of the water to be treated. The air diffuser according to claim 1.

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