JP6076733B2 - Update device from existing diffuser system to modified diffuser system and update method from existing diffuser system to modified diffuser system - Google Patents

Description

The present invention relates to an update device from an existing diffuser system to a modified diffuser system and an update method from an existing diffuser system to a modified diffuser system .

The activated sludge method is known as one of the aerobic biological treatment methods for biologically treating and purifying organic sewage such as sewage, human waste and industrial wastewater with aerobic microorganisms.
FIG. 6 shows a standard activated sludge process.
First, sewage to be treated (hereinafter referred to as treated water) is first guided to a settling basin. In the first settling basin, fine sand and SS (Suspended Solids) in the water to be treated are precipitated and removed by the action of gravity.
Next, the water to be treated is first introduced into the aeration tank from the settling basin. At this time, aerobic microorganisms (bacteria, mold, protozoa, etc.) were introduced into the aeration tank as seed sludge at the beginning of operation, and a large amount of aerobic microorganisms called activated sludge that grew using organic matter in the water to be treated were fed. The returned sludge contained in is returned and guided from the final sedimentation basin at the latter stage. In the aeration tank, an air diffuser for introducing air (oxygen) necessary for the activity of microorganisms into the tank and mixing the activated sludge sufficiently with the water to be treated is installed.

The air diffuser is provided with an infinite number of air holes, and when air is supplied from the blower through the air pipe, air is ejected from the innumerable air holes into the aeration tank. Can cause an upward flow of gas-liquid mixing. Therefore, when the return sludge containing a large amount of activated sludge is introduced into the aeration tank, the air diffuser sufficiently mixes the return sludge and the water to be treated, blows bubbled air into the water to be treated and aerates it. The oxygen concentration in water is increased, and the organic substance is removed by the metabolic action of microorganisms contained in the activated sludge.
Next, the mixed liquid of activated sludge overflowing the aeration tank and treated water is settled and separated in the final sedimentation basin because normal activated sludge is easy to separate, and the supernatant water is discharged as treated water. Or sent to advanced processing in a later process.
Next, of the activated sludge settled in the final sedimentation basin, the amount necessary for the aerobic waste water treatment is returned to the reaction tank (aeration tank) and used again as seed sludge for treatment.
In addition, the growth of sediment sludge is returned to the upstream of the first sedimentation basin as surplus sludge, collected as sedimentation basin sludge settled in the first sedimentation basin, and then processed separately.

FIG. 7 shows an example of an air diffusion system including a conventional air diffuser (see, for example, Patent Documents 1, 2, 3, 4, 5, and 6). In FIG. 7, for example, an aeration system including 10 aeration tanks 1A to 1J will be described.
In 10 tanks 1A-1J, the diffuser group 2 is arrange | positioned at each bottom face. The air diffuser group 2 includes a plurality of air diffusers 3 that aerate bubbles in the water to be treated in the aeration tanks 1A to 1J, and branch pipes 4 in which the air diffusers 3 are respectively arranged. Each branch pipe 4 is connected to an air pipe 5, the air pipe 5 is connected to one main pipe (existing header) 6, and five blowers 7 a to 7 e are connected to the main pipe 6 via original pipes 8 a to 8 e, respectively. Connected. Since the five blowers 7a to 7e are set so that one unit can supply air to the two and a half diffuser groups 2, the blower 7e functions as a spare in this example. The air pipe 5 is provided with a plurality of air control valves (not shown) for adjusting the total pressure (static pressure + dynamic pressure) of the compressed air supplied by the four blowers 7a to 7d for each of the aeration tanks 1A to 1J. Yes.

In FIG. 7, the aeration device group 2 in the 10 aeration tanks 1 </ b> A to 1 </ b> J is shown in a form in which three aeration devices 3 are arranged in one branch pipe 4 for convenience. The number of diffusers 3 and branch pipes 4 to be used is determined depending on the scale of the field. In addition, the number of aeration tanks varies depending on the size of each sewage treatment plant.
FIG. 5A is a graph showing the relationship between the blower discharge pressure and the blower air volume in the air diffusion system including the conventional air diffuser shown in FIG. In FIG. 5, the diffuser group 2 using the conventional diffuser 3 is shown as a standard system, and a diffuser using a panel-type membrane diffuser, which is a low-pressure loss diffuser described later. Groups are shown as low airflow systems.
In an air diffuser system equipped with a conventional air diffuser, by operating four blowers 7a to 7d, the resistance curve and the set value of the discharge pressure of the blower overlap to form an operating point.

In addition, as a conventional diffuser, for example, a plurality of diffuser plates using a square or circular diffuser element having no stretchability or shrinkage such as a mesh cloth, ceramic, resin, metal sintered body, etc. There are known diffuser devices that are arranged in pairs on the horizontal plane, and are connected via a rubber hose to a pipe that branches from a header pipe connected to an air supply hose that supplies air from above the water surface. (For example, see Patent Document 5).
The air diffuser of Patent Document 5 includes a rectangular or circular air diffuser element that is not stretchable or contractible, and a flexible diaphragm that has an air vent installed under the air diffuser element. When there is no air space, there is no space between the air diffuser element and the diaphragm, and when air is supplied, the lower diaphragm is bent downward by the air flow resistance of the air diffuser element to allow ventilation (patented) (Refer FIG. 1 of literature 5).

Further, as another conventional air diffuser, a rectangular elastic porous body, a support body that supports the rectangular elastic porous body from below and has an orifice for pressurized air, and a rectangular elastic porous body as a support body There is known an air diffuser that includes a fixing member that is integrally fixed to a pipe and that can be easily installed on a pipe for sending pressurized air (see, for example, Patent Document 6).
In Patent Document 6, an elastic porous body is obtained by molding an elastic material into a desired shape. Examples of the material of the porous body include ethylene propylene rubber (EPDM), silicon rubber, polyurethane, and chloroprene rubber. , Rubbers such as nitrile rubber, fluoro rubber (for example, registered trademark Viton, PTFE), perfluoroelastomer, and the like. Among these, ethylene propylene rubber is particularly preferable because it has high film strength and excellent heat resistance and water resistance. Further, fluororubber and perfluoroelastomer are preferable in terms of chemical resistance.
Two or more of the air diffusers of Patent Document 6 can be installed on a pipe for sending pressurized air to configure an air diffuser system (see FIG. 5 of Patent Document 6).

By the way, the power required to blow air supplied to the aeration tank is said to be 40% to 50% of the power consumed in the sewage treatment plant. Reduction of greenhouse gases by reducing CO ₂ emissions derived from energy used is expected.
Therefore, when reducing the blower power in order to reduce the aeration power, simply reducing the amount of blown air will reduce the DO (Dissolved Oxygen) in the aeration tank, MLSS (Mixed Liquor Suspended Solid) Substance), the quality of the treated water deteriorates and the original purpose of the sewage treatment facility cannot be achieved. In order to prevent this, gas and liquid can be supplied by supplying finer bubbles into the tank than conventional high pressure (high air volume) air diffusers made of ceramic or synthetic resin that can maintain DO in the aeration tank even with a small air volume. Aeration power can be reduced by introducing a fine bubble diffuser that is a highly efficient diffuser capable of efficiently dissolving oxygen by dramatically increasing the contact area.

Therefore, it is a low-pressure (low air volume) ultrafine air diffuser capable of reducing the blowing power when the above-described conventional ceramic or synthetic resin high pressure system (high air volume) air diffuser is modified. It has been proposed to replace the panel type membrane diffuser. The low pressure system (low air volume system) fine bubble diffuser generates small bubbles, so that oxygen is easily dissolved in the water to be treated. The low pressure system (low air volume system) fine bubble diffuser generates small bubbles, which greatly increases the degree of gas-liquid contact and makes it easier for oxygen to dissolve in the water to be treated. The amount of air used can be reduced to keep the water underwater and the amount of power used can be reduced. It is said that the introduction of a low pressure system (low air volume system) fine bubble diffuser enables approximately 20% power reduction compared to a conventional high pressure system (high air volume system) air diffuser.
A panel type membrane diffuser is an apparatus used for aeration of an aeration tank (see, for example, Patent Document 7).

The diffuser panel of the panel type membrane diffuser has a diffuser film on one side of a flat plate made of metal or synthetic resin, and the four sides of the diffuser membrane and the four sides of the base plate Is fixed to a metal frame through packing. The diffuser membrane has a large number of small holes, and the material thereof is made of synthetic resin or synthetic rubber having moderate elasticity such as polyurethane, silicon, ethylene propylene rubber and the like.
The panel-type membrane diffuser is a low-pressure (low air flow) diffuser, and can generate fine bubbles (ultrafine bubbles) having a diameter of, for example, about 1 mm. Compared with conventional diffusers, the bubble diameter is small and the specific surface area as the gas-liquid contact area is dramatically increased with the same air volume. Therefore, the efficiency of oxygen transfer into water is high, and the same oxygen transfer is performed in water. If aeration is performed, the amount of air blown to the aerobic reaction tank is reduced, and it can be expected that the amount of greenhouse gas derived from aeration energy is suppressed at the same time as power reduction.

FIG. 8 shows that a part of the conventional high pressure system (high airflow system) air diffuser group 2 is replaced with a new low airflow system (low airflow system) panel type membrane air diffuser 10. An example of the diffuser system after partial refurbishment is shown.
The work of replacing the conventional high pressure system (high airflow system) air diffuser group 2 with a new air diffuser group 9 using the low pressure system (low airflow system) panel type membrane air diffuser 10 In order not to interfere with the operation of the sewage treatment plant, it is actually introduced with the rated raw water amount in anticipation of the low raw water amount that does not become the raw water amount that needs to be aerobically treated using all of the aeration tanks 1A to 1J. Close a part of the aeration tank that handles a part of the difference from the amount of raw water to be drained, drain the water, and sequentially turn the high pressure system (high air volume system) diffuser group 2 into the low pressure system (low air volume system) The air diffuser group 9 is updated.

In this example, a new air diffuser using a panel type membrane air diffuser 10 is used as the high pressure system (high air flow system) air diffuser group 2 in the two aeration tanks 1E and 1G in the air diffuser system shown in FIG. The case where it replaces with the apparatus group 9 is demonstrated.
First, the on-off valves (not shown) of the branch pipes 4 of the air system of the two aeration tanks 1E and 1G (which may be combined with or separate from the air control valve) are closed, and then the raw water is in the two aeration tanks 1E and 1G. To prevent inflow, close the valve in the raw water inflow pipe, raise or close the raw water inflow weir, and then drain the treated water in the two aeration tanks 1E and 1G to The tanks 1E and 1G are emptied.
Next, the high pressure system (high air volume system) diffuser group 2 to be repaired in the two aeration tanks 1E and 1G is removed.
Next, a new air diffuser group 9 using the low pressure system (low air volume system) panel type membrane air diffuser 10 is disposed in the two aeration tanks 1E and 1G.

Next, open the raw water inflow piping valve, lower or open the raw water inflow weir, overflow the raw water inflow weir, introduce the raw water, and flow the raw water into the two aeration tanks 1E, 1G To do.
Next, the valve 12 of the new air diffuser group 9 using the low pressure system (low air flow system) panel type membrane diffuser 10 is opened to supply compressed air from the pipe 11.
Thus, the work of replacing the low pressure system (low air volume system) diffuser group 2 in the two aeration tanks 1E and 1G with the new diffuser group 9 using the panel type membrane diffuser 10 is completed. .

In the air diffuser system after the modification of the conventional high pressure system (high air flow system) air diffuser shown in FIG. 8, even if it is a low pressure system (low air flow system) panel type membrane air diffuser 10, From the pressure and the amount of blown air from each air diffuser, the valve 12 provided in the pipe 11 was throttled to bother resistance. The reason is that the air introduction piping system using the five blowers 7a to 7e is used as it is, and the five blowers 7a to 7e are operated at a low speed, so that the panel type membrane type of the low pressure system (low air flow system). This is because the amount of compressed air blown and the air pressure are too large for the air diffuser 10.
Patent Documents 1 to 4 show the technical level of an air diffusion system that supplies air to an air diffuser using a plurality of blowers in an air diffuser for an aeration tank.

JP 2006-116388 A JP 2012-200706 A JP 2004-041928 A JP 11-138191 A Japanese Patent No. 4539568 Japanese Patent No. 4846339 JP 2004-313938 A

As described above, in the diffused system after partial modification of the aeration tank of the conventional high pressure system (high air flow system) air diffuser group 2 shown in FIG. 7, the conventional high pressure system (high air flow system) air diffuser. Even if a part of the device group 2 is replaced with a low pressure system (low air flow system) panel type membrane diffuser 10, since there is only one air introduction piping system, the blower static pressure and the air flow rate of each air diffuser Therefore, the valve 12 of the pipe 11 of the low pressure system (low air flow system) panel type membrane diffuser 10 is throttled to bother resistance.
Therefore, when the conventional air diffuser shown in FIG. 7 is partially refurbished, in the process of sequentially changing the air diffuser in the aeration tank of the entire treatment plant, the power consumption of the blower 7 in the air diffuser system is Since the air diffuser system is not different from the conventional air diffuser system, the air blowing power reduction effect by the air diffuser group 9 of the panel type membrane diffuser 10 which is a low pressure loss type (low power type of carrier air power) diffuser. Could not get.

In addition, the air diffuser of Patent Document 6 uses a simple component configuration from the diffuser plate made of porcelain to the diffuser plate made of different materials while using the diffuser plate holder of the existing diffuser. 7 is a replacement-compatible diffuser, and the diffuser plate to be replaced may be a low-pressure loss type similar to the panel-type membrane diffuser 9, but the diffuser system shown in FIG. Similarly, since the power consumption of the blower 7 is the same as that of the conventional diffuser system, the effect of reducing the blast power by the low pressure loss diffuser cannot be obtained.
Moreover, in the air diffusion apparatus of patent document 6, since it replaces using the diffuser plate holder of many existing air diffusion apparatuses provided in one piping, there also exists a problem that work requires time and effort.
Further, in the air diffuser of Patent Document 6, even if the air diffuser plate holders of a number of existing air diffusers provided in one pipe are replaced, the air diffuser is diffused for each small area diffuser. Since it has a plate holder, there is also a problem that the diffused area is small as compared with one panel type membrane diffuser.

In Patent Document 1, in a diffuser facility for supplying aeration air from a lower diffuser pipe to a film immersed in an aeration tank, a plurality of blowers are connected in common at a header, and a large number during normal aeration operation. Disclosed is a technology that allows water to flow into the diffuser pipe by stopping the blower during the cleaning operation to clean sludge clogging in the diffuser pipe, releasing the pressurized air to the atmosphere with the header, and removing it rapidly. is there.
In this patent document 1, there is no disclosure of changing and updating an old diffuser to a membrane diffuser.
In Patent Document 2, in a diffuser system in which a panel-type membrane diffuser is provided in an aeration tank, the deposits deposited and adhered to the openings of the membrane membrane are washed. There is a disclosure of a technique in which a liquid cleaning chemical is accompanied and blown out from an opening of a membrane film.
In Patent Document 2, there is no disclosure of renewing while saving energy when an old diffuser is changed to a membrane diffuser.

In Patent Document 3, in a diffuser system in which a panel-type membrane diffuser is provided in an aeration tank, a large number of diffusers are provided so that the supply amount of air and air pressure can be uniformly and stably supplied to a large number of diffusers. By allowing air to be vented and stopped independently for each air device, the membrane is greatly expanded and contracted before deposits adhere to the openings of the membrane membrane in order to prevent adhesion, A technique is disclosed in which the air supply amount and pressure are uniform as a whole.
In this patent document 3, there is no disclosure of updating while saving energy when changing an old diffuser to a membrane diffuser.
Also in Patent Document 4, in an aeration apparatus that supplies air to an air diffuser provided in an aeration tank, a technique is provided in which an air blower with an inverter is provided for each air diffuser and the amount of air generated by each blower is adjusted according to the inflow load amount. It is disclosed.
In this patent document 4, there is no disclosure of updating while saving energy when changing an old diffuser to a membrane diffuser.

The present invention has been made in order to solve such a conventional problem, and an object of the present invention is to provide a conventional high pressure system (high air flow system) air diffuser having an air diffused portion made of ceramic or synthetic resin. Even when a part of the existing aeration tank is being refurbished, the installation of a low-pressure (low airflow) panel-type membrane-type air diffuser can be easily and easily adjusted. can, and which can be energy-saving operation of a part during renovation achieved is to provide a method of updating from the diffusion system update device and existing from the existing aeration system to repair air diffuser system to repair the air diffuser system .

The update device from the existing air diffuser system to the repair air diffuser system according to the present invention includes a plurality of aerobic treatment tanks containing treated water and a plurality of blowers via a plurality of original pipes provided with valves. The aerobic treatment tank includes a compressed air supply device connected to a header and a high-pressure (high air volume) air diffuser in which a plurality of air diffusers that are not stretchable or contractible are connected by branch pipes. A high-pressure system (high airflow system) air diffuser group disposed inside, and one air pipe that connects the existing header and the branch pipe of the high-pressure system (high airflow system) air diffuser group from the existing aeration system comprising, prior Symbol pressure system the air diffuser group (large air volume system), it is composed of a panel type membrane film low pressure loss for new branches established multiple aeration panels that generates small bubbles Low pressure system composed of low pressure system (low air flow system) diffuser connected by piping In the update device from the existing aeration system to repair diffuser system to replace the air diffuser group of the low air volume system), the updating unit, the multiple blower side of the valve of the plurality of original tubing, a valve and one header for updating connected via a plurality of branch source pipe provided, arranged before along Kioku trachea, through the newly branch pipes and air diffuser group of the low-pressure system (low air volume system) a and the header added Ru is connected to the air line for the update are connected Te, and an inverter that is installed to a part of the blower of the blower, before Symbol blower inverter is first installed, half of the Until the high-pressure system (high airflow system) diffuser group is replaced with the low-pressure system (low airflow system) diffuser group, the renewal blower is dedicated to the low-pressure system (low airflow system) air diffuser . More than half connected to the header The serial high-voltage air diffusion device group (large air volume system) as an air diffuser dedicated blower of the low voltage system the low-pressure system from substituting the diffuser groups (low air volume system) (low air volume system) existing When all the high-pressure (high airflow) diffuser groups are connected to the header and replaced with the low-pressure (low airflow) diffuser group, they are connected to the existing header and the update header. A part of the blower other than the blower in which the inverter is first installed includes only the existing header and the update header according to the replacement of the low pressure system (low air flow system) air diffuser group. Alternatively, the connection is switched to the connection between the existing header and the update header.

Further, the pressure gauge for detecting the pressure in the header for updating, from the difference between the set pressure value based on the detection signal from the pressure gauge, pressure regulator gauge to be output to the inverter calculates the frequency output of the inverter And a discharge pressure control device configured to control the discharge pressure of the blower connected to the update header.
Further, when replacing the high pressure system (high airflow system) diffuser group with the low pressure system (low airflow system) diffuser group, the number of low pressure system (low airflow system) diffuser groups is When the amount of the high pressure system (high air flow system) diffuser group is increased, compressed air is supplied from the additional air supply pipe to the air supply pipe to the low pressure system (low air volume system) air diffuser group. The update header is provided with a valve so that it can be opened and closed so as to be switched to.

Further, each of the aerobic treatment tanks is provided with one valve in each of the air supply pipe and the additional air supply pipe, and a branch pipe of the high-pressure system (high air volume system) air diffuser group through one side of the valve; Each time the low pressure system (low air flow system) diffuser group is connected to the air supply pipe, the low pressure system (low air flow system) diffuser group is installed through the other side of the valve. The additional air supply pipe is connected via a two-branch pipe, and the supply of compressed air to the low pressure system (low air volume system) air diffuser group is switched through one side of the valve or the other side of the valve. And
The pipe capacity per unit length of the additional air supply pipe is 40% or more and 50% or less of the pipe capacity per unit length of the air supply pipe.

Moreover, the update method from the existing air diffusion system to the modified air diffusion system according to the present invention includes a plurality of aerobic treatment tanks that store treated water and a plurality of blowers via a plurality of original pipes provided with valves. A compressed air supply device formed by connecting an existing header to the existing header, and a high pressure system (high air flow system) air diffusion device in which a plurality of air diffusion elements that are not stretchable or contractible are connected by branch pipes. One air pipe that connects the high pressure system (high air flow system) air diffuser group disposed in the treatment tank, and the existing header and the branch pipe of the high pressure system (high air volume system) air diffuser group. from the existing aeration system comprising bets, established before Symbol pressure system the air diffuser group (large air volume system), a plurality of diffuser panels consist of low pressure loss panel type membrane film generates small bubbles of new A low pressure system (low air flow system) diffuser connected by branch piping. System In the update method from the existing aeration system to replace the air diffuser groups (low air volume system) to repair the air diffuser system, wherein a plurality of blower side of the valve of the plurality of original tubing, a plurality of providing a valve One renewal header connected via the branching source pipe is provided in the compressed air supply device, and an additional air supply pipe connected to the renewal header is arranged along the air supply pipe and should be updated. The high pressure system (high air flow system) air diffuser group is sequentially removed for each predetermined number of aerobic treatment tanks, and the low pressure system (low air flow system) air diffuser group is removed. disposed at a position of the air diffuser groups large air volume system), so it arranged the low-pressure system (via the new branch pipes to the air diffuser group of the low air volume system) connecting the header for the update Connect the additional air pipe and connect an inverter to a part of the blower Installed, the blower in which the inverter is first installed, the low-pressure system until replaced by diffuser group of all the high-voltage the low voltage system the air diffuser group (large air volume system) (low air volume system) Connected to the renewal header or the existing header as a blower dedicated to the air diffuser of (low air flow system), and all the high pressure system (high air flow system) air diffuser group is the low pressure system (low air flow system) The diffuser group is connected to the existing header and the update header, the inverter is installed in a part of the blower other than the blower where the inverter is first installed, and the low-pressure system ( According to replacement of the diffuser group of the low air volume system, only the existing header, only the update header, or the connection between the existing header and the update header is switched.

Further, the pressure gauge for detecting the pressure in the header for updating, from the difference between the set pressure value based on the detection signal from the pressure gauge, pressure regulator gauge to be output to the inverter calculates the frequency output of the inverter And a discharge pressure control device configured to control the discharge pressure of the blower connected to the update header.
Further, when replacing the high pressure system (high airflow system) diffuser group with the low pressure system (low airflow system) diffuser group, the number of low pressure system (low airflow system) diffuser groups is When the amount of the high pressure system (high air flow system) diffuser group is increased, compressed air is supplied from the additional air supply pipe to the air supply pipe to the low pressure system (low air volume system) air diffuser group. It is characterized by switching to.

Further, each of the aerobic treatment tanks is provided with one valve in each of the air supply pipe and the additional air supply pipe, and a branch pipe of the high-pressure system (high air volume system) air diffuser group through one side of the valve; Each time the low-pressure system (low airflow system) diffuser group is connected to the air supply pipe, the low-pressure system (low airflow system) air diffuser group is installed through the other side of the valve. The additional air supply pipe is connected via a two-branch pipe, and the supply of compressed air to the low pressure system (low air volume system) air diffuser group is switched via one side of the valve or the other side of the valve. Features.
Further, the pipe capacity per unit length of the additional air line is characterized in that the feed is 50% or less 40% of the pipe capacity per unit length of trachea.

According to the present invention, when refurbishing an existing ceramic or synthetic resin high pressure system (high air flow system) air diffuser group, it is updated separately from the air pipe of the high pressure system (high air volume system) air diffuser group. A low-pressure system consisting of a panel-type membrane-type air diffuser that can be replaced by an inverter placed in a part of the blower that supplies compressed air to a high-pressure (high air volume) air diffuser. Since the compressed air is supplied by controlling the discharge pressure to the (low air volume system) air diffuser group, the blower power can be reduced, and an energy saving effect according to the progress of the update can be obtained.
Further, according to the present invention, the high pressure system (high air flow system) air diffuser group is sequentially updated to the low pressure system (low air flow system) air diffuser group, so that an energy saving effect can be obtained according to the number of updated units.

In one embodiment of the present invention, among the 10 aeration tanks 1A to 1J, the aeration apparatus groups 2 of the high pressure system (high air volume system) of the aeration tanks 1A and 1B are each diffused of the low pressure system (low air volume system). FIG. 6 is a conceptual diagram showing a state where the air device group 20 is replaced. In one embodiment of the present invention, among the 10 aeration tanks 1A to 1J, each of the aeration apparatus groups 2 of the high pressure system (high air flow system) of the aeration tanks 1A to 1E is replaced with each of the low pressure system (low air flow system). FIG. 6 is a conceptual diagram showing a state where the air device group 20 is replaced. In one embodiment of the present invention, among the 10 aeration tanks 1A to 1J, each aeration apparatus group 2 of the high pressure system (high air volume system) of the aeration tanks 1A to 1H is replaced with each diffuser of the low pressure system (low air volume system). FIG. 6 is a conceptual diagram showing a state where the air device group 20 is replaced. In one embodiment of the present invention, a state in which all of the high-pressure system (high airflow system) air diffuser group 2 in the 10 aeration tanks 1A to 1J are replaced with a low-pressure system (low airflow system) air diffuser group 20 FIG. (A) Relationship between the blower discharge pressure and the blower air volume of the air diffuser system including each of the high pressure system (high air volume system) air diffuser groups and (B) to (E) the high pressure system (high air volume system) When a part or all of the air diffuser system having each air diffuser group is replaced with an air diffuser system having each air diffuser group having a low pressure system (low air flow system), the blower discharge pressure and the blower It is a graph which shows the relationship with an air volume, respectively. It is a figure which shows the process of a standard activated sludge method. It is a conceptual diagram which shows an example of the diffuser system provided with the diffuser group of the conventional high voltage | pressure system (high air volume system). Part of the conventional high-pressure system (high airflow system) air diffuser group is replaced with a new air diffuser group using a low-pressure (low airflow system) panel-type membrane air diffuser. It is a conceptual diagram which shows an example.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
1 to 5 show an air diffuser system updating apparatus and an air diffuser system updating method according to an embodiment of the present invention.
In this embodiment, each aeration device group 2 of 10 aeration tanks 1 </ b> A to 1 </ b> J in the aeration system including the existing high-pressure system (high air volume system) aeration device group 2 shown in FIG. Are sequentially removed, and a new low pressure system (low air volume system) diffuser group 20 is disposed.
Although not described in detail in FIGS. 7 and 8, the air pipe 5 for supplying compressed air to each of the aeration apparatus groups 2 of the high pressure system (high air flow system) of the 10 aeration tanks 1 </ b> A to 1 </ b> J. Each of the aeration tanks is provided with a connecting pipe 13 which is a branch pipe, and each connecting pipe 13 is provided with a valve 14 at a connection portion with a branch pipe 4 of each diffuser group 2 of a high pressure system (high air flow system). Is provided. Each connecting pipe 13 has a tip provided with a valve 14 at a position where it can be connected to a branch pipe 4 in which each aeration device group 2 of a high pressure system (high air flow system) is arranged in 10 aeration tanks 1A to 1J. Has been placed.

Each low pressure system (low air flow system) air diffuser group 20 is configured by arranging a low pressure system (low air flow system) panel type membrane air diffuser (air diffuser panel) 21 in the pipe 22. . The pipe 22 is provided with a branch pipe 22 a that is a part of a new branch pipe connected to the valve 14.
The low pressure system (low air flow system) panel type membrane diffuser (diffuse panel) 21 has a diffuser film disposed on one surface of a base plate made of metal or synthetic resin. The diffuser surface is configured by fixing the four side edges and the four side edges of the base plate to a metal frame through packing. The diffuser membrane has a large number of small holes, and the material thereof is made of synthetic resin or synthetic rubber having moderate elasticity such as polyurethane, silicon, ethylene propylene rubber and the like.
The low-pressure (low airflow) panel-type membrane diffuser (aeration panel) 21 can generate fine bubbles (ultrafine bubbles) having a diameter of, for example, about 1 mm. Compared to conventional high pressure system (high air flow system) air diffuser, it has small specific surface area, so it has high oxygen transfer efficiency into water, and aerobic reaction when performing aeration to perform the same oxygen transfer into water The amount of air blown into the tank is about ½, and it can be expected to reduce the amount of greenhouse gas emissions at the same time as reducing power.

The work of replacing the high pressure system (high air flow system) air diffuser group 2 with a new air diffuser group 20 using the low pressure system (low air flow system) panel type membrane diffuser (air diffuser panel) 21 is as follows. In order not to interfere with the operation of the target sewage treatment plant, the estimated amount of raw water and actual introduction are measured in anticipation of the amount of raw water that does not become the amount of raw water that needs to be aerobically treated using all of the aeration tanks 1A to 1J. The aeration tanks with a part of the processing amount responsible for a part of the difference with the raw water amount to be closed are drained (for example, two of the 10 tanks can be closed), and the high pressure system (high air volume system) is scattered The air device group 2 is sequentially updated to a low pressure system (low air volume system) air diffuser group 20.
In this case, the difference from the updating apparatus and the updating method of the conventional aeration system shown in FIG. 8 is that the low-pressure system (low air volume system) aeration apparatus group 20 (the first in 10 tanks in FIG. 1) is replaced. 2 tanks 1A and 1B) are arranged along the air pipe 5 which is an air feed pipe, an air pipe 30 which is an additional air feed pipe, and between the air pipe 30 and the existing five blowers 7a to 7e. In addition, the branch pipes 42a to 42e are newly installed and arranged through the valves 42f to 42e at the respective connection portions through the header 43 for updating.

Furthermore, it is also possible to control the inverters 41 a and 41 b added to a part of the existing blowers 7 a to 7 e with the pressure gauge 16 in the header 43 for updating and to add a part of the existing blowers 7 a to 7 e by the blower discharge pressure in the header 43 for updating. When replacing the diffuser group 20 of the (low air volume system), it is to be newly installed.
When arranging each of the low pressure system (low air volume system) air diffuser groups 20, an air pipe 30 that is an additional air supply pipe is arranged along the air pipe 5. The air pipe 30 that is an additional air supply pipe has a capacity for supplying compressed air having a low air volume of 40% to 50% with respect to the capacity of the existing air pipe 5.
The air pipe 30 is provided with a connection pipe 31 which is a new branch pipe for attaching the pipes 22 of the aeration device groups 20 of the low pressure system (low air flow system) of the 10 aeration tanks 1A to 1J. Each connecting pipe 31 is provided with a valve 32 at the tip of the connecting portion with the pipe 22 of each diffuser group 20 of a low pressure system (low air volume system). Each connecting pipe 31 has a tip provided with a valve 32 disposed in a position where it can be connected to the piping 22 of each of the low pressure system (low air volume system) aeration devices 20 in the 10 aeration tanks 1A to 1J. Yes.

Compressed air for supplying compressed air to each of the high pressure system (high air flow system) air diffuser groups 2 and 10 newly installed low pressure system (low air volume system) air diffuser groups 20 of the 10 aeration tanks 1A to 1J The supply device 40 includes an existing header 6 that receives compressed air from the existing five blowers 7a to 7e and supplies the compressed air to the air pipe 5, and two blowers 7c and 7d among the existing five blowers 7a to 7e. (The ratio of old and new airflow between the diffuser group 20 and the diffuser group 2 is 2: 1, and before the refurbishment, if 4 units are operated except for spares, 2 units can be covered when the renovation is completed. Inverters 41a and 41b are provided between the motor and the commercial power supply, and upstream of the valves 8f to 8j installed for standby between the discharge sides of the existing five blowers 7a to 7e and the existing header 6 To install valves 42f to 42j on the way Via the branch pipe 42a~42e includes a header 43 for updates that are connected that.
Here, the existing blowers 7a, 7b, and 7e supply compressed air to the aeration tanks of two and a half tanks, that is, a quarter of the entire aeration tank group 2 of the high pressure system (high air volume system). The blowers 7c and 7d having the capacity and provided with the inverters 41a and 41b have a small air volume in each of the low pressure system (low air volume system) air diffuser groups 20, and thus each newly installed air diffuser group 20 It will have the ability to supply compressed air to 5 tanks, that is, 1/2 of the entire aeration tank.

The existing blowers 7a, 7b, 7e are operated at a constant speed by a commercial power source, and the existing blowers 7c, 7d are operated by inverter control. The inverters 41a and 41b perform control in accordance with the discharge pressure of the header 43 for updating so that the drive motor frequency of the existing blowers 7c and 7d is kept lower than the commercial frequency. The existing blowers 7c and 7d When the air supply destination is each newly installed air diffuser group 20, an air volume of 40% to 50% of the rating is discharged. Since the pressure required for discharge of each existing diffuser group 2 and each newly installed diffuser group 20 is often different, what percentage of the commercial frequency is case-by-case, but lower than the commercial frequency. .
The existing five blowers 7a to 7e are connected to one existing header 6 via pipes 8a to 8e provided with valves 8f to 8j. The existing header 6 is connected with an air pipe 5 for supplying compressed air to each of the aeration device groups 2 of the high pressure system (high air flow system) of the 10 aeration tanks 1A to 1J.

The pipes 8a to 8e are provided with branch pipes 42a to 42e that branch from between the valves 8f to 8j and the existing five blowers 7a to 7e. The branch pipes 42 a to 42 e are provided with valves 42 f to 42 j and are connected to the update header 43. The renewal header 43 is connected to an air pipe 30 that is an additional air supply pipe for supplying compressed air to each of the low pressure system (low air volume system) diffuser groups 20 to be newly arranged.
The existing five blowers 7a to 7e are connected to the intake pipe 15a to 15e on the intake side, and the intake pipe 15 is provided with an intake port 15f for introducing outside air.
In order to control the discharge pressure to each diffuser group 20 of the low pressure system (low air volume system) connected to the header 43 for update, the discharge pressure of the header 43 for update is a pressure gauge (ΔP) 16. The frequency output of the inverters 41a and 41b connected to the motors of the blowers 7c and 7d is controlled by the signal detected by the pressure controller (PIC) 17 and the outlet pressure of the blowers 7c and 7d is controlled to be constant. To do.

Hereinafter, each aeration device group 2 of the high pressure system (high air volume system) of the 10 aeration tanks 1A to 1E in the conventional aeration system shown in FIG. A case where each air diffuser group 20 of the system (low air flow system) is arranged will be described.
FIG. 1 shows each of the aeration devices 2 of the high pressure system (high air flow system) of the 2 aeration tanks 1A and 1B among the 10 aeration tanks 1A to 1J. The state replaced with the device group 20 is shown.
First, the operation of the blowers 7a, 7b, 7c, and 7e is continued, and the operation of the blower 7d is stopped. At the same time, the valves 14 in the two aeration tanks 1A and 1B are closed.
At this time, in the compressed air supply device 40, the valves 8f, 8g, 8i, 8j are opened, the valves 8h, 42f, 42g, 42i, 42j are closed, and the compressed air is generated by the operation of the blowers 7a, 7b, 7c, 7e. The air is supplied from the air pipe 5 to the air diffuser groups 2 of the high pressure system (high air volume system) in the aeration tanks 1C to 1J through the existing header 6.

However, since there are eight aeration tanks for supplying compressed air, the supply amount of compressed air from one blower is two and a half of the aeration tank, so the blowers 7a, 7b, 7c, 7e are operated at a constant speed. Then, since the supply amount of compressed air becomes two extra tanks, after adding the inverter 41b to the blower 7d, switching from commercial power supply to inverter panel power supply in anticipation of nighttime when there is less inflow of raw water, etc. Construction (Motor is compatible with the inverter from the beginning) is performed after the blower 7c is stopped for a short time after the addition of the inverter 41a to the blower 7c is completed, and the blower 7c is restarted, so that the blower 7c is throttled by the inverter 41a. As described above, supply of compressed air to the eight aeration tanks 1C to 1J is adjusted.
That is, among the 10 aeration tanks 1A to 1J, the aeration apparatus group 2 of the high pressure system (high air flow system) of the 2 aeration tanks 1A and 1B is replaced with each of the aeration apparatus groups of the low pressure system (low air flow system). As a result, the discharge flow rate from the existing header 6 of each of the high-pressure system (high airflow system) air diffuser group 2 becomes excessive, and the blower 7c is throttled manually by the inverter 41a. become.

At this time, the blowers 7 a, 7 b, 7 c, and 7 e are not connected to the update header 43, so that compressed air is not supplied to the update header 43.
Therefore, in the eight aeration tanks 1C to 1J, compressed air is supplied from the existing header 6 as before by the operation of the blowers 7a, 7b, 7c, and 7e. System (high air flow system) each aeration device group 2 thoroughly mixes the returned sludge and the water to be treated, blows air into the water to be treated and aerates it to increase the oxygen concentration in the water to be treated The effect | action which removes organic substance is show | played by the metabolic action of the microorganisms contained in sludge.
That is, in the eight aeration tanks 1 </ b> C to 1 </ b> J, the action of removing organic substances in the water to be treated by each of the high-pressure (high air volume) aeration apparatus groups 2 is not interrupted.

At this time, the relationship between the discharge pressure of the blowers 7a, 7b, 7c, and 7e and the air volume of the blowers 7a, 7b, 7c, and 7e is such that the inverter 41b is connected to the blower 7d as shown in the standard system of FIG. Since the blower 7c performs the throttle operation by the inverter 41a by adding to the air diffuser group 20 of the low pressure system (low airflow system) first, the parallel combined airflow of the three blowers 7a, 7b and 7e-static The air volume and the pressure are further accumulated on the pressure (pressure), and can be supplied at a predetermined pressure to the operating point which is the air volume for 8 tanks. This is the optimum energy saving control because the fourth parallel blower is throttled and operated by inverter control that saves electric power. FIG. 5A shows that the flow rate for the eight tanks as the operating point matches the point where the resistance curve and the combined discharge pressure of the four blowers overlap.
Next, in order to prevent the raw water from flowing into the two aeration tanks 1A and 1B, a valve in the middle of the raw water inflow pipe (not shown) is closed, or the raw water inflow weir is raised or closed, so that the two aeration tanks The treated water in 1A and 1B is drained to empty the two aeration tanks 1A and 1B.
Next, the branch pipes in which the air diffuser group 2 of the high pressure system (high air flow system) to be repaired in the two aeration tanks 1A and 1B are separated from the valves 14 of the air pipe 5 and the air diffuser 3 is arranged. Remove 4
As described above, the removal of each of the diffuser groups 2 of the high pressure system (high air flow system) to be repaired in the two aeration tanks 1A and 1B is completed.

Next, in each of the two aeration tanks 1A and 1B, the low-pressure (low air volume) aeration device group 20 is disposed, and the renewal air pipe 30 corresponding to the two aeration tanks 1A and 1B is provided. The valve 32 provided at the tip of each connecting pipe 31 is connected to each pipe 22 of each high-pressure system (high air volume system) air diffuser group 2, and the branch pipe 22 a of each pipe 22 is connected to the valve 14. . At this time, the valve 32 is closed, and compressed air is not ejected from the connection pipe 31 of the renewal air pipe 30.
Next, when the connection between each valve 32 and each pipe 22 of each diffuser group 2 of the high pressure system (high air flow system) is completed, each valve 32 is opened, the valve 8i of the compressed air supply device 40 is closed, and the valve 42i is opened, and the construction for switching from the commercial power supply to the inverter panel power supply is completed during the stoppage, so that the compressed air is connected to the update header 43 by the operation of the blower 7d controlled by the inverter 41b. The air is supplied to a valve 32 provided at the tip of each connecting pipe 31 through the air pipe 30, and is supplied from the valve 32 to each air diffuser group 20 of the low pressure system (low air volume system) through the pipe 22.
Next, the raw water inflow pipe is opened or the raw water inflow weir is lowered or opened to overflow the raw water inflow weir and introduce the raw water into the two aeration tanks 1A and 1B. Inflow.

As described above, the work of replacing the high pressure system (high air volume system) diffuser group 2 in the two aeration tanks 1A and 1B with the low pressure system (low air volume system) air diffuser group 20 is completed.
At this time, the discharge pressure and the air volume of the blower 7d are supplied to the two groups of air diffusers 20 in the low pressure system (low air volume system) in the two aeration tanks 1A and 1B. For the blower 7d having the ability to supply the air diffuser group 20 of (low air flow system), the throttle operation is performed by pressure control, and the operation point shown in the low air flow system of FIG. The capacity of the low pressure system (low air volume system) diffuser group 20 for two tanks can be exhibited.
Thus, in the diffused system after the initial update shown in FIG. 1, all the existing blowers 7a to 7e are operated, and each diffused air in the high pressure system (high air flow system) in the eight aeration tanks 1C to 1J. In the apparatus group 2, the existing blower 7c is throttled by the newly installed inverter 41a, and the compressed air generated by the existing blowers 7a to 7c, 7e is supplied from the existing header 6 via the air pipe 5, In each of the low pressure system (low air flow system) diffuser groups 20 in the two aeration tanks 1A and 1B, the existing blower 7d is controlled by the newly installed inverter 41b and updated from the header 43 for updating. Compressed air can be supplied via the air pipe 30.

FIG. 2 shows each of the high pressure system (high air flow system) air diffuser groups 2 in the low pressure system (low air flow system) of the 10 aeration tanks 1A to 1J. The state replaced with the air device group 20 is shown.
The procedure for replacing each high-pressure system (high airflow system) air diffuser group 2 in the aeration tanks 1C to 1E with each low-pressure system (low airflow system) air diffuser group 20 is shown in FIG. This is the same as replacing the high pressure system (high air volume system) diffuser group 2 in the aeration tanks 1A and 1B with the low pressure system (low air volume system) diffuser group 20.
In the compressed air supply device 40, the valve 8h of the pipe 8c connected to the blower 7c is closed, the valve 42h of the branch pipe 42c is opened, the valve 8i of the pipe 8d connected to the blower 7d is closed, and the valve 42i of the branch pipe 42d is opened. The compressed air generated by the blowers 7c and 7d is supplied to the header 43 for updating. The blower 7e is stopped as a spare.

Here, even if one blower 7d is operated, compressed air can be supplied to each of the low pressure system (low air volume system) diffuser groups 20 in the five aeration tanks 1A to 1E, but the blowers 7c and 7d are provided. The control operation by the inverters 41a and 41b is energy saving. Therefore, the pressure regulator calculation signal described later is set so that the inverter 41a can receive the pressure so that the blower 7c can also control the pressure, and the pressure regulator (PIC) 17 calculates based on the signal from the pressure gauge (ΔP) 16. The frequency output of the inverters 41a and 41b connected to the motors of the blowers 7c and 7d is controlled by the signal so that the discharge amount is half that of the existing blower.
Compressed air generated by the blowers 7 a and 7 b is supplied from the existing header 6 through the air pipe 5 to each of the high pressure system (high air volume system) in the remaining five aeration tanks 1F to 1J. Supplied.

Compressed air generated by controlling the blowers 7c and 7d by the inverters 41a and 41b is supplied to each of the low-pressure (low airflow) diffuser groups 20 in the five aeration tanks 1A to 1E. 43 through an air pipe 30 for renewal.
At this time, the relationship between the discharge pressure of the blowers 7a and 7b and the air volume is, as shown in the standard system of FIG. 5C, the parallel combined air volume-static pressure (pressure) of the two blowers 7a and 7b. , It can be supplied at a predetermined pressure to the operating point which is the air volume of just 5 tanks. Naturally, it moves to the side with less air volume than FIG. 5 (B) for 8 tanks. In this case, it can be said that it is an optimal energy-saving operation because it can cover just 5 tanks with the combined capacity of 2 units.
At this time, the relationship between the discharge pressure of the blowers 7c and 7d and the air volume is 2 while the blower 7e is stopped and the blowers 7c and 7d are inverter-controlled as shown in the low air volume system of FIG. The air volume and the pressure are accumulated as a parallel composite air volume-static pressure (pressure) at the table, and can be supplied to the operating point, which is the air volume for 5 tanks, at a predetermined pressure. This is the optimum energy saving control because it is performed by inverter control that saves electric power when the throttle operation is performed in parallel with the second unit in order to optimally adjust the pressure. In FIG. 5 (C), the flow rate of each of the diffuser groups 20 in the low pressure system (low air volume system) for five tanks as the operating point coincides with the point where the combined resistance pressure of the resistance curve and the two blowers overlap. The operating point at which the resistance curve and the blower discharge pressure overlap is five tanks as compared to the operating point shown in the low air volume system of FIG.

  Thus, in the diffused air system after the update shown in FIG. 2, the existing blower 7e is used as a backup, the existing blowers 7a to 7d are operated, and the high pressure system (high air flow system) in the five aeration tanks 1F to 1J is used. ) Is supplied to the air diffuser group 2 of the existing blowers 7a and 7b from the existing header 6 through the air pipe 5, and the low pressure system in the five aeration tanks 1A to 1E. In each air diffuser group 20 of (low air volume system), the existing blowers 7c and 7d are controlled and operated by newly installed inverters 41a and 41b and compressed from the update header 43 via the update header 43. Air can be supplied.

FIG. 3 shows that each of the high pressure system (high air volume system) of the aeration tanks 1A to 1H of the 10 tanks 1A to 1J is divided into each of the low pressure system (low air volume system). The state replaced with the air device group 20 is shown.
The procedure for replacing each high-pressure system (high airflow system) air diffuser group 2 in the aeration tanks 1F to 1H with each low-pressure system (low airflow system) air diffuser group 20 is shown in FIG. This is the same as replacing the high pressure system (high air volume system) diffuser group 2 in the aeration tanks 1A and 1B with the low pressure system (low air volume system) diffuser group 20.
In the compressed air supply device 40, the valve 8g of the pipe 8b connected to the blower 7b is opened, the valve 42g of the branch pipe 42b is closed, and the compressed air generated by the blower 7b is supplied to the existing header 6. Further, unlike the case where each of the low pressure system (low air flow system) diffuser groups 20 in FIG. 2 is replaced, the valve 8h of the pipe 8c connected to the blower 7c is closed and the valve 42h of the branch pipe 42c is closed. And the compressed air generated by the blower 7c is supplied to the header 43 for updating. Further, the valve 8i of the pipe 8c connected to the blower 7d is opened, and the valve 42i of the branch pipe 42d is replaced with the low pressure system (low air flow system) diffuser group 20 of a total of 5 tanks in FIG. And the compressed air generated by the blower 7d is supplied to the existing header 6. The blowers 7a and 7e are stopped as spares when the eight tanks are updated.

  The eight aeration tanks 1A to 1H are replaced with low-pressure (low air volume) air diffuser groups 20, and the diameter of the pipe is used to blow compressed air through the renewed air pipe 30 which is an additional air pipe. Because there is a shortage, the responsibility of the air pipe is reversed. That is, compressed air is supplied to each diffuser group 20 of the low pressure system (low air volume system) via the existing header 6 and the air pipe 5, and each diffuser group 2 of the high pressure system (high air volume system). , Compressed air is supplied through the header 43 for updating and the air piping 30 for updating. For this reason, the last remaining high pressure system (high air flow system) air diffuser group 2 branches off the downstream side of the valve 13 of the branch pipe 14, and is updated by providing a new branch pipe 22a and a valve 31 at the tip. A pipe 32 extending from the air pipe 30 is connected, the valve 13 of the branch pipe 14 is closed, and the valve 31 of the pipe 32 is opened.

Here, the blowers 7b and 7d can supply compressed air to each of the low pressure system (low air flow system) diffuser groups 20 in the eight aeration tanks 1A to 1H. Since the compressed air becomes unnecessary, the frequency output of the inverter 41b connected to the motor of the blower 7d is manually set, and the parallel combined airflow-static pressure (both of the blower 7b and the blower 7d that are operated at a rated value) The air volume and the pressure are accumulated as pressure) and adjusted so that the operating point, which is the total air volume of the low pressure system (low air volume system) diffuser group 20 for 8 tanks, can be supplied at a predetermined pressure.
The remaining two aeration tanks 1 </ b> I and 1 </ b> J are supplied with compressed air generated by the blower 7 c through the renewal air pipe 30 to each of the high pressure system (high air volume system) diffuser group 2. For the blower 7c having a supply capacity to the air diffuser group 2 of the high pressure system (high air flow system) of two and a half tanks, the throttle operation is performed, and the set pressure value is determined based on the detection signal from the pressure gauge (ΔP) 16. The frequency of the inverter 41a is set by the inverter frequency output signal calculated and output by the pressure controller (PIC) 17 from the difference, and the blower 7c is controlled and operated.

The relationship between the discharge pressure of the blower 7c and the air volume of the blower 7c at this time is as shown in the standard system of FIG. 5D. The high pressure system (high air volume system) in the remaining two aeration tanks 1I and 1J In each of the diffuser groups 2), the blower 7 c having a supply capacity to each of the diffuser groups 2 of the high pressure system (high air flow system) of two and a half tanks is throttled, and from the pressure gauge (ΔP) 16 Based on the difference from the set pressure value based on the detected signal, the inverter frequency output signal calculated and output by the pressure controller (PIC) 17 sets the frequency of the inverter 41a and controls the blower 7c to operate the two tanks. It becomes the operating point of the total supply air volume to each air diffuser group 2 of the high-pressure system (high air volume system).
At this time, the relationship between the discharge pressure of the blowers 7b and 7d and the air volume of the blowers 7b and 7d is that the blowers 7a and 7e are stopped and the blower 7b is stopped as shown in the low air volume system of FIG. In order to make commercial blower 7d perform throttle operation by inverter control with commercial power supply, blower 7d is further combined with air flow-static pressure (pressure) of blower 7b and parallel combined air flow-static pressure (pressure). ) And the air volume and pressure can be stacked and supplied to the operating point, which is the air volume for 8 tanks, at a predetermined pressure. This is the optimum energy saving control because the second parallel blower is throttled and operated by inverter control that saves electric power. In FIG. 5D, it can be shown that the flow rate of the eight tanks as the operating point matches the point where the resistance curve and the composite discharge pressure of the two blowers overlap.

  Thus, in the air diffuser system after the update shown in FIG. 3, the existing blowers 7a and 7e are used as spares, the existing blowers 7b to 7d are operated, and the high-pressure system (high pressure) in the two aeration tanks 1I and 1J is set. In each air diffuser group 2 of the air volume system), an existing blower 7c is provided with an inverter 41a, and a pressure regulator (PIC) 17 is calculated from a difference from a set pressure value based on a detection signal from the pressure gauge (ΔP) 16. In the inverter frequency output signal that is calculated and output at, the compressed air generated by setting the frequency of the inverter 41a and controlling the blower 7c is supplied from the update header 43 via the air pipe 30; In each of the low pressure system (low air flow system) diffuser groups 20 in the eight aeration tanks 1A to 1H, the existing blower 7b is operated at commercial rating, and the existing blower 7d is manually set by the newly installed inverter 41b. Driving and existing It is possible to supply compressed air via the air pipe 5 from the header 6.

FIG. 4 shows a state in which all of the high pressure system (high air flow system) air diffuser groups 2 in the 10 aeration tanks 1A to 1J are replaced with the low pressure system (low air flow system) air diffuser group 20.
The procedure for replacing each high-pressure system (high airflow system) air diffuser group 2 in the aeration tanks 1I and 1J with each low-pressure system (low airflow system) air diffuser group 20 is shown in FIG. This is the same as replacing the high pressure system (high air volume system) diffuser group 2 in the aeration tanks 1A and 1B with the low pressure system (low air volume system) diffuser group 20.
In the present embodiment, the valve 14 connected to the branch pipe 22a of each pipe 22 of each diffuser group 20 of the low pressure system (low air volume system) is opened, and the existing air pipe 5 and the air pipe 30 for update are used. Supply compressed air.
Therefore, the existing valve 14 is opened during operation.

In the compressed air supply device 40, the valve 8h of the pipe 8c connected to the blower 7c and the valve 42h of the branch pipe 42c are opened, and the compressed air generated by the blower 7c is sent to the existing header 6 and the header 43 for header update. Supply. Further, the valve 8i of the pipe 8c connected to the blower 7d and the valve 42i of the branch pipe 42d are opened, and the compressed air generated by the blower 7d is supplied to the existing header 6 and the update header 43. The blowers 7a, 7b and 7e are stopped as a spare.
Compressed air generated by the blowers 7c and 7d controlled by the inverters 41a and 41b is supplied to each of the low pressure system (low air volume system) diffuser groups 20 in the 10 aeration tanks 1A to 1J. From the existing air pipe 5 and the renewal header 43 through the renewal air pipe 30.

  At this time, the relationship between the discharge pressure of the blowers 7c and 7d and the air volume of the blowers 7c and 7d is that the blowers 7a, 7b and 7e are stopped, as shown in the low air volume system of FIG. In order to perform the throttle operation of the inverter 7d by the inverter control, the air volume and the pressure are accumulated as a parallel combined air volume-static pressure (pressure) in two units in which the blower 7d is further added to the air volume-static pressure (pressure) of the blower 7c. It can be supplied at a predetermined pressure to the operating point which is the air volume for 10 tanks. This is the optimum energy saving control because the two parallel blowers are throttled by pressure and are controlled by inverter control that saves power. Both the blowers 7c and 7d have the capacity of the total air volume of each of the low pressure system (low air volume system) air diffuser groups 20 for five tanks, so that the inverter frequency is close to commercial use. When the initial pressure loss is low, the optimum optimum energy saving control can be performed. FIG. 5E shows that the flow rate of 10 tanks as the operating point matches the point where the resistance curve and the composite discharge pressure of the two blowers overlap.

As shown in the standard system of FIG. 5 (E), all the diffuser groups 2 of the high-pressure system (high air volume system) have been removed, and this system does not exist, so the corresponding operation exists. do not do.
Thus, in the air diffuser system after all updates shown in FIG. 4, the existing blowers 7a, 7b, 7e can be used as spares, for example, two units can be removed, and the existing blowers 7c, 7d are connected to the inverters 41a, 41b. Newly installed and controlled, the commercial rated operation of the four blowers before the update is changed to the inverter control operation with the possibility of throttling the two blowers after the complete update. Compressed air generated by the blowers 7c and 7d is supplied from the existing header 6 and the updating header 43 to each of the low pressure system (low air volume system) diffuser groups 20 in the tank aeration tanks 1A to 1J. be able to.

In the present embodiment, by using the existing air pipe 5 and the renewal air pipe 30 together, air is supplied to one low pressure system (low air volume system) diffuser group 20 in two systems. The blower energy can be saved by reducing the pressure loss of the piping system.
However, since the flow rate adjustment is necessary again, the flow rate adjustment of the existing valve 14 is performed manually.
In the above embodiment, each of the high pressure system (high airflow system) air diffuser groups 2 of the 10-layer aeration tanks 1A to 1J is sequentially replaced with each low pressure system (low airflow system) air diffuser group 20. Although demonstrated, this invention is not restricted to this, The number of aeration tanks is arbitrary.
Moreover, although the case where the compressed air supply apparatus 40 was comprised with the five blowers 7a-7e and inverter 41a, 41b was demonstrated, it is not restricted to this in this invention, The number of a blower and an inverter is arbitrary.

1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J Aeration tank 2 High pressure system (high air volume system) air diffuser group 3 High pressure system (high air volume system) air diffuser 4 Branch pipe 5 Air pipe 6 as an air supply pipe Existing headers 7a, 7b, 7c, 7d, 7e Blowers 8a, 8b, 8c, 8d, 8e Main pipe 13 Connection pipes 14, 32, 8f, 8g, 8i, 8j as branch pipes 42f, 42g, 42h, 42i, 42j Valve 15 Intake piping 15a, 15b, 15c, 15d, 15e, 22 Piping 16 Pressure gauge (ΔP)
17 Pressure controller (PIC)
20 Low pressure system (low air flow system) diffuser group 21 Panel type membrane diffuser (diffuse panel)
22a Branch pipe 30 Air pipe 31 which is an additional air pipe 31 Connection pipe 40 which is a new branch pipe Compressed air supply devices 41a and 41b Inverters 42a, 42b, 42c, 42d and 42e Branch pipe 43 Header for updating

Claims (10)

A plurality of aerobic treatment tanks containing treated water;
A compressed air supply device comprising a plurality of blowers connected to an existing header via a plurality of original pipes provided with valves;
A high-pressure system (high airflow system), which is composed of a high-pressure system (high airflow system) of air diffuser connected with branching pipes and a plurality of non-stretchable and shrinkable elements. A diffuser group of
From an existing air diffuser system comprising the existing header and one air pipe connecting the branch pipe of the high pressure system (high air flow system) air diffuser group,
The high-pressure system (high airflow system) air diffuser group is a low-pressure system (low airflow system) that consists of a newly installed low-pressure-loss panel-type membrane membrane that connects multiple diffused panels that generate small bubbles with new branch pipes. In the update device from the existing diffuser system to the modified diffuser system, which replaces the low-pressure (low airflow) diffuser group consisting of diffuser
The update device
One update header connected to the plurality of blower sides from the valves of the plurality of original pipes via a plurality of branch source pipes provided with valves,
An additional air supply pipe disposed along the air supply pipe, connected to the low-pressure system (low airflow system) air diffuser group via the new branch pipe and connected to the header for updating;
An inverter installed in a part of the blowers, and
The blower in which the inverter is first installed has the low-pressure system (low air volume) until the half of the high-pressure system (high air volume system) diffuser group is replaced with the low-pressure system (low air volume system) air diffuser group. System) as a blower dedicated to the air diffuser, connected to the header for update, and more than half of the air diffuser group of the high pressure system (high air flow system) is connected to the low pressure system (low air flow system) Is replaced with the existing header as a blower dedicated to the low pressure system (low air volume system) air diffuser, and all the high pressure system (high air volume system) air diffuser groups are connected to the low pressure system (low air volume system). When the system is replaced with a group of air diffusers, the existing header and the update header are connected,
A part of the blower other than the blower where the inverter is first installed is only the existing header according to the replacement of the low pressure system (low air flow system) diffuser group, only the header for updating, Alternatively, the apparatus is switched to the connection between the existing header and the update header. The update device from the existing diffuser system to the repair diffuser system. In the update device from the existing air diffuser system according to claim 1 to the modified air diffuser system,
A pressure gauge for detecting the pressure in the header for updating;
A discharge pressure control device comprising a pressure regulator that calculates a frequency output of the inverter from a difference from a set pressure value based on a detection signal from the pressure gauge, and outputs the frequency output to the inverter;
An apparatus for updating an existing diffuser system to a modified diffuser system, wherein the discharge pressure of the blower connected to the header for update is controlled. In the update device from the existing air diffusion system according to claim 1 or claim 2 to the modified air diffusion system,
When replacing the high pressure system (high airflow system) air diffuser group with the low pressure system (low airflow system) air diffuser group, the number of the low pressure system (low airflow system) air diffuser group is When the number of high-pressure (high airflow) air diffusers increases, the supply of compressed air to the low-pressure (low airflow) air diffusers is switched from the additional air supply pipe to the air supply pipe. An update device from an existing diffuser system to a modified diffuser system, wherein the valve for update is provided with a valve that can be opened and closed. In the update apparatus from the existing air diffusion system in any one of Claims 1 thru | or 3 to a repair air diffusion system,
One valve is provided for each of the air supply pipe and the additional air supply pipe for each of the aerobic treatment tanks, and the branch pipe of the high-pressure system (high air volume system) air diffuser group and the supply pipe are provided through one side of the valve. A new second branch of the low pressure system (low air flow system) diffuser group is connected through the other side of the valve every time the low pressure system (low air flow system) air diffuser group is installed. The additional air supply pipe is connected via a pipe, and the supply of compressed air to the low pressure system (low air volume system) air diffuser group is switched via one side of the valve or the other side of the valve. Update device from the existing diffuser system to the modified diffuser system. In the update apparatus from the existing air diffusion system according to any one of claims 1 to 4 to a modified air diffusion system,
The pipe capacity per unit length of the additional air pipe is 40% to 50% of the pipe capacity per unit length of the air pipe from the existing air diffuser system to the modified air diffuser system Update device. A plurality of aerobic treatment tanks containing treated water;
A compressed air supply device comprising a plurality of blowers connected to an existing header via a plurality of original pipes provided with valves;
A high-pressure system (high airflow system), which is composed of a high-pressure system (high airflow system) of air diffuser connected with branching pipes and a plurality of non-stretchable and shrinkable elements. A diffuser group of
From an existing air diffuser system comprising the existing header and one air pipe connecting the branch pipe of the high pressure system (high air flow system) air diffuser group,
Low-pressure system (low airflow system) that consists of a low-pressure-loss panel type membrane membrane that connects the high-pressure system (high airflow system) with a plurality of diffuser panels that generate small bubbles and is connected by a new branch pipe In the update method from the existing diffuser system to the modified diffuser system, which is replaced with the low pressure system (low airflow system) diffuser group consisting of
One compressed header connected to the plurality of blower sides from the valves of the plurality of original pipes via a plurality of branch source pipes provided with valves is provided in the compressed air supply device,
An additional air pipe connected to the header for update is disposed along the air pipe,
The aeration device group of the high pressure system (high air flow system) to be updated is sequentially removed for each predetermined number of the aerobic treatment tanks,
The low pressure system (low air flow system) air diffuser group is disposed at the position of the removed high pressure system (high air flow system) air diffuser group,
The additional air supply pipe is connected so as to connect the header for update to the low pressure system (low air flow system) diffuser group disposed through the new branch pipe,
An inverter is installed in a part of the blowers,
The low-pressure system (low air volume) until the blower in which the inverter is first installed is replaced with the low-pressure system (low air volume system) diffuser group in place of all the high-pressure system (high air volume system) air diffuser groups. Connected to the header for update or the existing header as a blower dedicated to the air diffuser of the system),
When replacing all the high-pressure system (high airflow system) diffuser group with the low-pressure system (low airflow system) diffuser group, connect to the existing header and the update header,
An inverter is installed in a part of the blower other than the blower in which the inverter is initially installed, and only the existing header is used for the update according to replacement of the low pressure system (low air flow system) air diffuser group A method of updating from an existing air diffuser system to a modified air diffuser system, characterized in that the connection is switched to only the header or a connection between the existing header and the header for update. In the update method from the existing air diffuser system according to claim 6 to the modified air diffuser system,
A pressure gauge for detecting the pressure in the header for updating;
A discharge pressure control device comprising a pressure regulator that calculates a frequency output of the inverter from a difference from a set pressure value based on a detection signal from the pressure gauge, and outputs the frequency output to the inverter;
A method of updating an existing diffuser system to a modified diffuser system, wherein the discharge pressure of the blower connected to the header for update is controlled. In the update method from the existing air diffuser system according to claim 6 or claim 7 to the modified air diffuser system,
When replacing the high pressure system (high airflow system) air diffuser group with the low pressure system (low airflow system) air diffuser group, the number of the low pressure system (low airflow system) air diffuser group is When the number of high-pressure (high airflow) air diffusers increases, the supply of compressed air to the low-pressure (low airflow) air diffusers is switched from the additional air supply pipe to the air supply pipe. A method for updating an existing air diffuser system to a modified air diffuser system. In the update method from the existing air diffuser system according to any one of claims 6 to 8 to a modified air diffuser system,
One valve is provided for each of the air supply pipe and the additional air supply pipe for each of the aerobic treatment tanks, and the branch pipe of the high-pressure system (high air volume system) air diffuser group and the supply pipe are provided through one side of the valve. A new second branch of the low pressure system (low air flow system) diffuser group is connected through the other side of the valve every time the low pressure system (low air flow system) air diffuser group is installed. The additional air supply pipe is connected via a pipe, and the supply of compressed air to the low pressure system (low air volume system) air diffuser group is switched via one side of the valve or the other side of the valve. How to update existing diffuser system to repair diffuser system. In the update method from the existing air diffuser system according to any one of claims 6 to 9 to a modified air diffuser system,
The pipe capacity per unit length of the additional air pipe is 40% to 50% of the pipe capacity per unit length of the air pipe from the existing air diffuser system to the modified air diffuser system Update method.

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