JP2001269692A - Aeration method and aeration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To subject a drain having an oil component to aeration treatment and also to obtain a high capturing efficiency by setting a specified gas-liquid contact space for aeration in a drain tank and sending air for aeration into the tank. SOLUTION: The drain near the liquid surface in the tank and containing oil is taken into a casing 11 from suction pipes 14 and 15 through intake ports 12 and 13. The drain is aerated in the gas-liquid contact space S by sending air from an air-sending part 21. The drain after aeration is discharged from a discharge port and reduced in speed by colliding with a baffle plate 25, then the waste water is dispersed around and released to the liquid surface. The generation of a voltex flow having the possibility of descending flow on the surface of the liquid surface is prevented, and the rising of the oil component is not disturbed and the capturing ratio of the oil component into the casing 11 is kept high.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aeration method and an aeration apparatus used for a grease trap for preventing oil contained in kitchen wastewater from leaking out, preventing clogging of a drain pipe and preventing water pollution of a river. Things.

[0002]

2. Description of the Related Art In a relatively large-scale kitchen such as a hotel or a restaurant, a large amount of oil-containing wastewater is discharged. Therefore, it is mandatory to install a grease trap called a grease trap at a stage prior to discharge into general sewage. Have been. This grease trap generally has a configuration in which drainage is once introduced into a tank having a submerged weir, where oil is floated on the liquid surface, and drainage not passing through the submerged weir is discharged from a downstream tank. are doing. Regarding the removal of oil floating on the liquid surface, for example, Japanese Patent Application Laid-Open No. 9-299975 and
As disclosed in JP-A-314167, in order to activate aerobic microorganisms that decompose oil, it is necessary to send air through the entire tank and aerate the air to decompose and remove the oil. Proposed.

[0003]

However, according to the above-mentioned conventional technique, the air for aeration at the time of aeration is mixed and stirred in the entire tank, and the oil trap which is the original purpose of the grease trap is increased. It is difficult to maintain with efficiency. As a result, there was a problem that a large amount of oil contained in the kitchen drainage was discharged from the building in which the kitchen was installed, causing water pollution of the river and blocking a water distribution pipe downstream of the grease trap.

[0004] Such a situation is caused by the fact that the wastewater in the entire tank is mixed and stirred when the air for aeration is sent to the entire tank. Therefore, if a specific gas-liquid contact space for aeration is set in the tank, air for aeration is sent into the space, the wastewater in the tank is aerated, and the treated wastewater is returned to the tank. It is believed that the disadvantages of mixing and stirring are corrected. In addition, by adopting such a configuration, it is possible to positively promote the miniaturization and reassembly of the bubbles supplied for aeration, increase the contact area with the waste water, and increase the dissolved oxygen concentration.

In this case, since the aeration itself needs to be performed on the wastewater containing oil, it is necessary to suck the oil floating on the surface of the drainage tank by a pump or the like and flow it into the gas-liquid contact space. On the other hand, the wastewater after aeration needs to be discharged from the gas-liquid contact space and returned to the tank. At this time, attention should be paid to the discharge from the discharge port. That is, if the drained water after aeration is discharged from one upper discharge port, an eddy flow is generated on the drainage surface in the drainage tank, and a downward flow is formed at the corner of the drainage tank. This downward flow contains undecomposed oil components and, for example, when a first tank is set on the upstream side, obstructs upward separation of oil flowing from the first tank into the drain tank (second tank). As a result, more oil flows out to the other tank downstream (third tank), and part of the oil also flows out to the drain pipe directly connected to the third tank. May cause a decrease. Also, the amount of oil floating on the liquid level in the second tank was reduced,
There is also a concern that the amount of oil taken into the specific gas-liquid contact space set in the tank may be reduced.

[0006] The present invention has been made in view of the above points, and a specific gas-liquid contact space for aeration is set in a tank.
A new aeration method that does not form a downward flow when discharging water after aeration into the tank while sending air for aeration into the tank to aerate the wastewater in the tank and the aeration method. It is an object of the present invention to provide an aeration apparatus capable of suitably implementing the above, and to solve the above problem.

[0007]

In order to achieve the above object, according to the first aspect, a step of taking drainage in a drainage tank containing oil into a casing vertically arranged in the drainage tank; A process of feeding the introduced wastewater to aerate the wastewater in the casing, and subsequently discharging the wastewater after the aeration to the drainage tank from a discharge port at an upper portion of the casing located above the liquid level of the drainage tank. And a discharge method, wherein the discharge is performed by dispersing in a plurality of directions during the discharge.

According to this method, the wastewater containing oil in the wastewater tank is taken into the casing, and the taken-in wastewater is aerated in the casing. Therefore, the wastewater in the entire tank is mixed and stirred. There is no. The drainage after aeration is dispersed in multiple directions from the discharge port at the top of the casing and discharged into the tank, so that eddy currents in the wastewater stored in the tank can be suppressed. The generation of a downflow that has occurred is also suppressed. Since aeration treatment can be performed on wastewater containing oil in the casing, it is possible to increase the contact area with wastewater by actively promoting the miniaturization and reassembly of bubbles supplied for aeration. It is possible to increase the dissolved oxygen concentration to promote the activation of aerobic microorganisms to promote the decomposition of oil, while suppressing the generation of anaerobic microorganisms and suppressing the generation of putrefaction odor. In addition, that the discharge port at the upper part of the casing is located above the liquid level in the drainage tank means that the lower end of the discharge port is located above the still water level of the drainage in the drainage tank.

According to the second aspect, the step of taking the drainage in the drainage tank containing oil into the casing vertically arranged in the drainage tank, and supplying the wastewater by feeding the wastewater taken in. Aerating in the casing, and then discharging the drained water after the aeration into the drainage tank from a discharge port in the upper part of the casing located above the liquid level of the drainage tank. Before performing the aeration, the flow rate of the discharged wastewater is reduced.

According to the aeration method of the second aspect, when discharging the drained water after aeration from the discharge port in the upper part of the casing into the tank, the flow rate of the discharged drainage is reduced before falling to the liquid level. As a result, the generation of a downward flow can be suppressed.

According to the third aspect, the step of taking the wastewater in the drainage tank containing oil into the casing arranged in the vertical direction in the drainage tank; And a step of discharging the drained water after the aeration to the drainage tank from a discharge port at the upper part of the casing located above the liquid level of the drainage tank. In the discharging, the wastewater is dispersed in a plurality of directions. Aerating method wherein the flow rate of the discharged wastewater is reduced after the discharge and before dropping onto the liquid surface after the discharge.

According to the aeration method of this type, since the water is dispersed at the time of discharge into the tank and the flow velocity of the wastewater is reduced, the eddy flow is generated more effectively than the aeration method of the first and second aspects. And the generation of a downward flow can be suppressed. Therefore, it is particularly effective when the discharge amount is large.

According to a fourth aspect of the present invention, there is provided an aeration apparatus installed in a drainage tank for storing wastewater containing oil, wherein a casing forming a gas-liquid contact space therein, and a drainage tank provided in the gas-liquid contact space. A suction section for taking in drainage water inward and upward, and an air supply section for sending air into the gas-liquid contact space, wherein drainage is taken into the gas-liquid contact space from the suction section and the air supply section is provided. After the air is sent into the gas-liquid contact space and the wastewater is aerated, the wastewater is discharged from the discharge port at the upper part of the casing to the liquid surface of the drainage tank,
An aeration apparatus is provided, which has a plurality of the discharge ports.

According to the aeration apparatus having such a configuration, the drainage introduced into the casing by the suction section is subjected to aeration treatment by air supply from the air supply section, and then from the plurality of discharge ports at the upper portion of the casing, after the aeration. The drainage can be dispersed and discharged on the liquid surface of the drainage tank. Therefore, the aeration method according to claim 1 can be suitably implemented. It is preferable that the suction section has a suction port near the liquid level in the tank for the purpose of taking in the floating oil. The air supply section only needs to supply gas to the gas-liquid contact space in the casing. As the gas to be supplied, oxygen is suitable. Of course, air containing oxygen may be used. Various gases may be supplied to the gas-liquid contact space.

In this case, if a baffle plate is provided on the front surface of the discharge port as described in claim 5, the aerated drain water dispersed and discharged from the plurality of discharge ports once collides with the baffle plate. Therefore, the flow velocity can be temporarily reduced.
Therefore, the aeration method according to claim 3 can be suitably implemented. Here, the front surface may be any surface on which the discharged drainage collides, and if the discharge port is open upward, the baffle plate is provided above the discharge port.

According to a sixth aspect of the present invention, there is provided an aeration apparatus installed in a drainage tank for storing wastewater containing oil, wherein a casing having a gas-liquid contact space therein, and a drainage tank provided in the gas-liquid contact space. A suction section for taking in drainage water inward and upward, and an air supply section for sending air into the gas-liquid contact space, wherein drainage is taken into the gas-liquid contact space from the suction section and the air supply section is provided. After the air is sent into the gas-liquid contact space and the wastewater is aerated, the wastewater is discharged from the discharge port at the upper part of the casing to the liquid surface of the drainage tank,
An aeration apparatus is provided, wherein a baffle plate is provided on a front surface of the discharge port.

According to this aeration device, the drained water discharged from the discharge port after the aeration can once collide with the baffle plate to reduce its flow velocity. Therefore, the aeration method according to claim 2 can be suitably implemented.

The discharge port of each of the aeration devices is opened along the liquid surface of the drainage tank, that is, in the horizontal direction, as in claim 7, or upwardly as in claim 8. You may. In the case of opening upward, it is preferable to provide an outwardly protruding flange portion at the periphery of the discharge port as described in claim 9, and to use the drainage after aeration to drop onto the surface of the drainage. The generation of eddy current can be further suppressed.

According to a tenth aspect, there is provided an aeration apparatus installed in a drainage tank for storing wastewater containing oil,
A casing forming a gas-liquid contact space therein, a suction unit for taking in the drainage water in the drainage tank into the gas-liquid contact space, and an air supply unit for sending air into the gas-liquid contact space. Drainage is taken into the gas-liquid contact space from the suction part, and is sent into the gas-liquid contact space by the air supply part to aerate the wastewater. The discharge port is configured to discharge to a liquid surface of a water tank, and the discharge port is provided on an upper portion of the casing, extends in a horizontal direction, and is formed on a side surface of a discharge path whose extension end is closed. A featured aeration device is provided.

In this aeration apparatus, the drainage aerated in the gas-liquid contact space temporarily flows out in a horizontal direction through a discharge path, and is then discharged from a discharge port formed on the side of the discharge path. Since the extension end, that is, the terminal end in the outflow direction, is closed, the drainage stream collides at the end, and
The momentum diminishes. On the other hand, since the discharge port is formed on the side surface, that is, in a direction perpendicular to the drain flow, the flow rate of the drained water discharged from the discharge port after aeration is reduced. Therefore, the generation of the downward flow can be suppressed.

In this case, if a plurality of the discharge paths are provided as in the eleventh aspect, the discharge can be performed in a dispersed manner, which is more effective. Further, even if a plurality of discharge ports are formed in the discharge path as described in the twelfth aspect, the discharge is dispersed and discharged, so that the generation of the downflow can be suppressed more effectively.

If at least a part of the upper surface of the discharge path is open, that is, open to the atmosphere, the discharge from the discharge port can be realized smoothly. Here, the cross-sectional shape of the discharge path can be appropriately selected.
Considering the easiness in processing and forming the discharge port on the side surface (side wall), a material having a concave cross section is suitable.

Although the shape of the discharge port itself is arbitrary, when an opening is provided on the upper surface of the discharge path, a slit shape formed vertically to reach the opening is suitable. I have.

If the opening area of the discharge port in each of the above aeration devices is made variable as in claim 15, an optimum discharge flow rate according to the operating conditions and the like can be selected. For example, when the discharge port has a slit shape, this can be easily realized by providing a slide shutter in the slit so as to make the width direction variable.

In each of the above aeration devices, when the drainage tank (that is, the drainage tank in which the casing is installed) communicates with another drainage tank, the drainage water in the other drainage tank is subjected to the gas-liquid contact. Can be taken into space,
Another suction unit may be added. That is, a plurality of suction units may be provided, and the drainage containing oil from the upper part of the other drainage tank communicating therewith may be taken into the gas-liquid contact space of the casing. Thereby, for example, the oil flowing into the downstream tank can be collected and aerated.

In each of the above aeration devices, if the casing is configured to be detachable from the supporting member attached to the wall forming the drainage tank, maintenance, inspection, and cleaning can be performed. It is convenient. As the detachable structure, for example, it is preferable that the casing is slid upward to be able to be pulled out, since the trouble of adjusting the height of the casing set is eliminated.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described. FIG. 1 shows an outline of a grease strap 2 using an aeration apparatus 1 according to the embodiment. Has three drainage tanks of a first tank A, a second tank B, and a third tank C in order from the upstream side. The three drainage tanks of the first tank A, the second tank B, and the third tank C are partitioned by vertically arranged partition plates 3 and 4, and are formed below each of the partition plates 3 and 4. Communication ports 5 and 6. The upper ends of the partition plates 3 and 4 are set so as to be located above the liquid level of the drainage in the tank, and a sufficient height is ensured so that the oil floating on the liquid level does not flow into other tanks. ing.

Drainage from a kitchen or the like flows into a first tank A on the most upstream side from a drainage inflow pipe 7. A discharge pipe 8 is provided in the third tank C on the most downstream side, and the drainage discharged from the discharge port 8a of the discharge pipe 8 flows into a sewer or the like. In the discharge pipe 8, an inflow portion 8b into the pipe is set below the liquid level, so that the oil floating on the liquid level of the third tank C flows in as it is, and the oil is discharged to the discharge port. 8a is prevented from being discharged. Further, a partition weir 9 is provided on the bottom surface of the second tank B, and the drainage of the first tank A flowing from the communication port 5 is directly discharged from the communication port 6.
Through the third tank C.

The aeration apparatus 1 according to the present embodiment is mounted on the surface of the second tank B of the partition plate 4 and is installed in the second tank B. Details of the aeration apparatus 1 will be described with reference to FIG. This aeration device 1
Has a substantially rectangular cylindrical casing 11 having a closed bottom surface and an open top surface, and the casing 11 is disposed in a tank in a vertical direction. A gas-liquid contact space S is formed inside the casing 11. In the present embodiment,
The upward flow path of the drainage taken in from the intake ports 12 and 13 is vertically divided into に よ っ て by a partition wall 11a and the like,
Further, the flow path is rotated 90 degrees on the way, and this time, the partition 11b
A gas-liquid contact space S is formed, which is divided into halves in the lateral direction, thereby increasing the gas-liquid contact efficiency and performing an aeration process without bias. .

Under the casing 11, drainage inlets 12 and 13 are formed to face each other. The intake port 12 is connected to a suction pipe 14 as a suction unit, and the intake port 13 is connected to a suction pipe 15 as a suction unit. Then, when air is pressure-fed by a compressor 22, which will be described later, the pressure in the casing 11 decreases, and the suction pipes 14, 15
Through the inlets 12 and 13, the drainage in the tank is introduced into the casing 11. The operation of taking in the drainage can be performed independently for each of the suction pipes 14 and 15.

The suction pipes 14 and 15 have the same configuration, have a configuration in which they are bent at an angle in the middle and extend upward in the vertical direction. It has suction ports 14a and 15a.

In the casing 11, an intake port 12,
An air supply unit 21 is provided at a location below 13. This air supply unit 21 is composed of a main body 21 having a large number of blow holes 21a.
b, and a supply unit 21c provided inside the main body 21b and provided outside the casing 11. When air, for example, as air for aeration is supplied to the supply unit 21c by the compressor 22 installed outside the tank,
The air is supplied to the gas-liquid contact space S from the outlet 21a.

An opening at the upper end of the casing 11 forms a discharge port 23. Above the discharge port 23, as shown in FIG.
4, a baffle plate 25 is provided. This baffle 2
When the size of the rectangular discharge port 23 is X × Y, the dimension of (5) is (X / 2 to 3X) × (Y / 2 to 3Y). The distance d1 from the end surface of the discharge port 23 to the lower surface of the baffle plate 25 is preferably about 10 mm to 100 mm.

A mounting member 26 having a wide insertion portion 26a penetrating vertically is fixed to the rear surface of the casing 11 (FIG. 3). When the casing 11 is installed in the second tank B, as shown in FIG.
Support member 2 having a substantially L-shaped side surface fixed to the wall surface of partition plate 4
7 is inserted into the insertion portion 26a, and the entire casing 11 is slid downward.

When installing the aeration apparatus 1 according to the present embodiment, the suction pipe 15 on the rear side is installed in the third tank C as shown in FIG. Therefore, the suction pipe 15 passes through the partition plate 4 and is connected to the intake port 13 of the casing.

Aeration apparatus 1 according to the first embodiment
Has a configuration as described above. When used, as shown in FIG. 1, the rear surface of the casing 11 is attached to a support member 27 fixed to the wall surface of the partition plate 4 of the second tank B. Insert the member 26 and move the aeration apparatus 1 to the second tank B
Installed in In this case, when the mounting member 26 is locked by the support member 27 in advance, the discharge port 23 is set in the second tank B.
If the length of the support member 27 and the position where the mounting member 26 is fixed to the casing 11 are set so as to be positioned above the liquid level, the height adjustment of the aeration apparatus 1 is unnecessary, and the operation is simple and quick. it can.

Thereafter, the waste water from the kitchen or the like which flows into the first tank A from the drain inflow pipe 7 and flows into the second tank B through the communication port 5 is taken into the casing 11 by the suction pipe 14 and the third drain. The drainage containing oil floating near the liquid level in the tank C is taken into the casing 11 by the suction pipe 15. Then, aeration air is supplied from the air supply unit 21 to the taken-in wastewater to perform aeration in the gas-liquid contact space S. As a result, the oil content is decomposed by the aerobic microorganisms, and the anaerobic microorganisms are killed, thereby preventing the generation of putrid odor.

The waste water after being subjected to the aeration treatment in the gas-liquid contact space S is discharged upward through a discharge port 23 having an open upper surface, and a baffle plate 25 is provided on the front surface, that is, above. As a result, the discharged waste water collides with the baffle plate 25 and the flow velocity is reduced. After that, it is dispersed and discharged around the discharge port 23. Therefore, the flow velocity at the time of reaching the liquid surface is slow, and the liquid is dispersed and discharged to the surroundings.
Further, it is possible to prevent the downward flow at the corner of the tank. Therefore, the rise of the oil flowing into the second tank B from the communication port 5 is not prevented, and as a result, the casing 1
It is possible to prevent the amount of oil taken in 1 from being reduced.
Furthermore, the entire second tank B is not agitated. Therefore, it is possible to prevent a decrease in oil collecting efficiency due to air supply. Moreover, the baffle plate 25 can prevent the discharged drainage flow and bubbles from being scattered upward and scattered when the air bubbles burst, and contaminate the atmosphere where the grease strap 2 is installed. Can also be suppressed.

In addition, the aeration apparatus 1 according to the present embodiment takes in the drainage floating near the liquid level of the third tank C into the casing 11 by the suction pipe 15 and performs aeration treatment. The accumulation of oil on the tank C can be prevented,
The oil decomposition performance of the entire grease trap 2 can be improved, and the generation of offensive odor due to anaerobic conditions in the third tank C can be prevented.

At the time of periodic inspection and maintenance, the casing 11 is pulled up to allow the support member 26 to be pulled up.
Since this can be removed from the device, the removal work at the time of maintenance can be greatly reduced.

The casing 1 in the above embodiment
As shown in FIG. 4, if a flange 23 a is further provided around the periphery of the discharge port 23 of the first discharge port 23, the drainage of the drainage from the baffle plate 25 at the time of discharge from the discharge port 23 (slap downward) Flow) directly falls on the liquid surface of the second tank B,
The formation of a downward flow in the tank B can be prevented. In this case, the width W of the flange portion 23a is preferably about 10 mm to 50 mm. This flange portion 23a is particularly effective when the discharge amount from the discharge port 23 is large.

Next, another embodiment will be described. FIG. 5 shows an aeration apparatus 3 according to the second embodiment.
1 shows an overview of the whole, and members and the like indicated by the same reference numerals as those of the aeration apparatus 1 according to the first embodiment in the figure indicate the same members and the like as the aeration apparatus 1. In the aeration device 31 according to the second embodiment, a discharge member 32 is provided on the upper end surface of the casing.
Is attached.

As shown in FIG. 6, the discharge member 32 has two horizontally opened discharge ports 33 and 34 which communicate with the gas-liquid contact space S. After the aeration process, the waste water is dispersed from these two discharge ports 33 and 34 from the upper portion of the casing 11 and discharged in the horizontal direction. As shown in FIG. 7, these two discharge ports 33 and 34 are set so as to discharge in a horizontal direction at a predetermined opening angle θ. The range of the opening angle (the included angle) θ is suitably 30 ° to 90 °.

The aeration apparatus 31 according to the second embodiment has the above configuration, and
Drainage after aeration in the gas-liquid contact space S
Dispersed from the two discharge ports 33 and 34 and discharged in the horizontal direction. Therefore, generation of an eddy current on the liquid surface in the tank is suppressed, and formation of a downward flow in a corner of the tank can be suppressed.

In such a case, as shown in FIG.
If a baffle plate 36 is attached to the front surface of each of the discharge ports 33 and 34 via a stay 35, the drained water discharged from the discharge ports 33 and 34 after aeration collides with the baffle plate 36, and the flow velocity thereof is reduced. Therefore, it is possible to further suppress the generation of the eddy current. The baffle plate 36 is effective when the discharge amount from the discharge ports 33 and 34 is large. In such a case, the discharge port 3
The distance d2 between 3, 34 and the baffle plate 36 is 10 mm to 5 mm.
About 0 mm is suitable. Also, the dimension of the baffle plate 36 in the horizontal direction is one of the opening widths of the discharge ports 33 and 34.
It is appropriate that the length in the vertical direction is 1/2 to 2 times the length of the discharge ports 33 and 34 in the vertical direction.

As the casing 11 used in each of the above embodiments, a casing having a rectangular tube shape as a whole can be used.
Of course, the casing is not limited to this, and various types of casings can be adopted. Also, the gas-liquid contact space S is not of a single shape, but is divided vertically to form a plurality of smaller gas-liquid contact spaces. Is also good.

For example, the upward flow path of the wastewater taken in from the intake ports 12 and 13 is vertically divided into に, １ ／, etc. in a strip shape, and the flow path is rotated by 90 degrees on the way, and this time. By partitioning into 短, １ ／, and the like in a substantially rectangular shape in the horizontal direction, the gas-liquid contact efficiency is increased, and the aeration process can be performed without bias.

Next, experimental results for verifying the effect of the present invention are shown below. In the experiment, the grease trap 2 shown in FIG. 1 was used, and the inflow of the drainage from the drainage inflow pipe 7 was set to 100 liters per batch, and pseudo drainage in which 600 g of lard was mixed into 100 liters of the hot water at 50 ° C. was used. . Regarding the inflow of the pseudo drain, the pseudo drain is introduced into the first tank A at a flow rate of 120 l / min from a pseudo drain storage container (not shown) installed at a position higher than each tank through a water supply pipe (not shown).
Was. Then, the amount of lard in the simulated drainage discharged from the third tank C was measured, and the blocking efficiency, that is, the measured lard amount / 600 g, was obtained in percentage.

The aeration device used in the experiment was the first
An aeration apparatus 1 according to the second embodiment, an aeration apparatus 31 according to the second embodiment, and an aeration apparatus 41 of a model in which a vortex is easily generated as shown in FIG. This aeration device 41
The casing 11, the air supply unit 21, and the suction pipes 14 and 15 are the same as the aeration apparatus 1 according to the first embodiment and the aeration apparatus 31 according to the second embodiment, respectively. Just outlet 42
Is different only in the configuration.

The discharge port 42 of the aeration device 41
Is a single discharge port configuration opened in the horizontal direction, and its size is a square of 75 mm × 75 mm. On the other hand, the size of the discharge port 23 of the aeration apparatus 1 according to the first embodiment used in the experiment is 75 mm × 75 mm.
mm, and the size of the baffle 25 is 170 mm × 90.
mm and the distance d1 from the discharge port 23 to the baffle plate 25.
Is 130 mm. Further, the discharge ports 33, 3 of the aeration apparatus 31 according to the second embodiment used in the experiment.
4 is 130 mm × 50 mm, and the size of the baffle plate is 150 mm × 70 mm.
The distance d2 from 3, 34 to the baffle plate 36 is 20 to 70
mm. The height from the liquid level in the tank to the discharge ports of the aeration devices 1, 31, and 41 of each type is 3
00 mm. The discharge amount from the discharge ports of the aeration devices 1, 31, and 41 of each type is 60 to 100.
Liters per minute.

In each experiment, the collection efficiency of 100 liters of pseudo drainage was determined each time, and a total of 20 experiments were performed. The results are shown in the table of FIG. 10 and the graph of FIG. In the table of FIG. 10, "41", "1", and "31" indicate the aeration devices 41, 1, and 31, respectively. As can be seen from these tables and graphs, the aeration device 1 according to the first embodiment and the aeration device 31 according to the second embodiment can achieve a high blocking efficiency of 97% or more. Although it gradually decreases thereafter, even at the 20th time, it is still possible to maintain a high blocking efficiency of almost 94%.

On the other hand, in the case of the aeration apparatus 41 having a single discharge port 42, it is 90% at the beginning, and it is less than 90% at the 20th time. Despite having exactly the same casing 11, gas-liquid contact space S, air supply unit 21, and suction pipes 14, 15, such a difference occurred as shown in FIG. In the case of the aeration device 41, by discharging from the discharge port 42,
A vortex (indicated by "x" in the figure) is generated in the second tank B,
As a result, a downward flow is formed at the corner of the tank, the rise of the oil content of the drainage flowing from the first tank A into the second tank B through the communication port 5 is suppressed, and the amount of oil taken into the casing 11 is reduced. Seem.

On the other hand, the aeration apparatus 1 according to the first embodiment and the aeration apparatus 31 according to the second embodiment suppress the generation of the vortex due to the discharge from the discharge port. The amount of oil taken into the inside is larger than that of the aeration device 41, and higher collection efficiency can be realized.

Next, a third embodiment will be described.
FIG. 13 shows an overview of an aeration apparatus 51 according to the third embodiment in accordance with an actual machine, and members and the like denoted by the same reference numerals as those of the aeration apparatus 1 according to the first embodiment are aeration. The same members and the like as the device 1 are shown. The aeration apparatus 51 according to the third embodiment includes a casing 1 as shown in FIG.
A discharge member 53 that forms a discharge path 52 is attached to the upper end surface of the nozzle 1.

The discharge member 53 covers the opening 11c on the upper surface of the casing 11 and has a generally gutter-like shape extending in the horizontal direction. The discharge path 52 communicates with the gas-liquid contact space S. The discharge member 53 has its extended end 53a closed, and has a slit-shaped discharge port
Are formed.

The discharge member 53 extends parallel to the front surface of the casing 11 and in the horizontal direction when viewed from a plane, and has a shape bent to the front side by an angle φ in the middle as shown in FIG. ing. The bent portion has a form in which a part of the upper surface is opened, and the upper end of the discharge port 54 reaches this opening. The angle at the time of bending, that is, the angle φ, is suitably 0 ° to 60 °. The length of the extended portion after bending is preferably about 2 to 3 times the width of the casing 11.

Each suction port 14 of the suction pipes 14 and 15 of the aeration apparatus 51 according to the third embodiment.
Above the a and 15a, columns 55 arranged in an annular shape, respectively.
A cover 56 is provided on the top. These pillars 55 function as fences for collecting coarse dust and garbage.

The main features of the aeration apparatus 51 according to the third embodiment are as described above. The installation and use are the same as those of the first embodiment, and the gas-liquid contact space S The drainage that has been subjected to the aeration treatment in the inside flows out from the opening 11 c on the upper surface of the casing 11 to the discharge passage 52 formed in the discharge member 53, and is discharged from the discharge port 5.
4 is discharged onto the liquid surface. Therefore, the flow velocity at the time of discharge is weakened, and the generation of eddy flow on the liquid level in the tank is suppressed,
The formation of a downward flow at the corner of the tank can be suppressed. Also, since a part of the upper surface of the discharge path 52 is open,
Such ejection is also performed smoothly.

Next, using the aeration apparatus 51 according to the third embodiment, an experiment conducted under exactly the same conditions as the experiment in which the effect of the aeration apparatus 1 according to the first embodiment described above was investigated. The results are shown below.

The table of FIG. 15 shows the cumulative blocking efficiency for each experiment and the graph of FIG. 16 shows the change of the cumulative blocking efficiency based on the results. As can be seen from these tables and graphs, the aeration apparatus 5 according to the third embodiment
According to No. 1, the interception efficiency is further improved as compared with the aeration apparatus according to each of the above-described embodiments, and the interception efficiency is maintained at almost 95% even after performing 70 times.

The discharge path 52 of the aeration apparatus 51 according to the third embodiment is constituted by a discharge member 53 having a substantially gutter shape as a whole. Of course, the discharge member may have a substantially cylindrical shape or a flow path. Circular or semicircular cross sections can also be used. Furthermore, although the discharge port 54 has a slit shape, any shape can be selected. Then, a plurality of discharge ports or discharge members may be provided.

[0062]

According to the aeration method of the present invention,
Since the wastewater in the entire tank is not mixed and stirred, the grease trap, which is the original purpose of the grease trap, can be maintained with high efficiency, and the downstream drain pipe is not blocked. Since the aeration process is performed in the gas-liquid contact space in the casing, it is possible to actively promote the miniaturization and re-assembly of the gas bubbles supplied for aeration and increase the contact area with the wastewater. By increasing the concentration of dissolved oxygen, the activation of aerobic microorganisms is promoted to promote the decomposition of oil, and on the other hand, the generation of anaerobic microorganisms can be suppressed and the generation of putrefactive odor can be suppressed. Furthermore, it is possible to suppress the generation of the eddy flow in the wastewater stored in the tank, and to suppress the generation of the downflow described above. Therefore, it is possible to increase the amount of oil taken into the casing and maintain a high collecting efficiency.

According to the aeration apparatus of the present invention of claims 4 to 17, the aeration method of the present invention can be suitably implemented. In particular, the aeration apparatus according to claim 16 can also treat wastewater containing oil from another wastewater tank. In the aeration apparatus according to the seventeenth aspect, workability during maintenance and cleaning is good.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an overall outline of a grease strap using an aeration apparatus according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional side view of the aeration apparatus according to the first embodiment of the present invention.

FIG. 3 is a perspective view of an upper part of a casing of the aeration apparatus according to the first embodiment of the present invention.

FIG. 4 is a perspective view of an example in which a flange is provided at a peripheral portion of a discharge port of the aeration apparatus of FIG. 3;

FIG. 5 is a side view of an aeration apparatus according to a second embodiment of the present invention.

FIG. 6 is a perspective view of an upper portion of a casing of an aeration apparatus according to a second embodiment of the present invention.

FIG. 7 is an explanatory diagram from a plane showing an opening angle of a discharge port at an upper part of a casing of the aeration apparatus of FIG. 6;

FIG. 8 is a perspective view showing an example in which a baffle plate is provided on the front surface of a discharge port of the aeration apparatus of FIG.

FIG. 9 is an explanatory diagram showing an overall outline of a grease trap using an aeration apparatus of a type that easily generates a vortex.

FIG. 10 is a table showing experimental results for comparing the blocking efficiency between the aeration apparatus of FIG. 9 and the aeration apparatuses according to the first and second embodiments.

11 is a graph showing the relationship between the number of experiments and the blocking efficiency based on the experimental results of FIG.

FIG. 12 is an explanatory view from a plane showing the generation of a vortex by the aeration apparatus of FIG. 9;

FIG. 13 is a perspective view of an aeration apparatus according to a third embodiment of the present invention.

FIG. 14 is a perspective view of an upper portion of a casing of the aeration apparatus according to the third embodiment.

FIG. 15 is a table showing experimental results of blocking efficiency of the aeration apparatus according to the third embodiment.

FIG. 16 is a graph showing the relationship between the number of experiments and the blocking efficiency described based on the experimental results of FIG.

[Explanation of symbols]

 Reference Signs List 1,31 Aeration device 2 Grease strap 3,4 Partition plate 5,6 Communication port 7 Drainage inflow pipe 8 Drain pipe 11 Casing 12,13 Intake port 14,15 Suction pipe 21 Air supply unit 22 Compressor 23,33,34,54 Discharge port 25, 36 Baffle plate 52 Discharge path 53 Discharge member A First tank B Second tank C Third tank S Gas-liquid contact space

Continued on the front page (72) Inventor Jin Inaba 3-46-30 Wakamatsu, Sagamihara City, Kanagawa Prefecture (72) Inventor Atsushi Takahashi 2-17-17 Kokubunkita, Ebina-shi, Kanagawa Prefecture (72) Inventor Takaya Inoue Chiyoda-ku, Tokyo 2-10-10 Fujimi Maeda Construction Industry Co., Ltd. (72) Inventor Hiroshi Tabuchi 4-15-3 Higashikomagata, Sumida-ku, Tokyo Shimoda Kiko Co., Ltd. F-term (reference) 4D028 AA03 AB00 BC24 4D029 AA01 AA09 AB05 BB10 CC06 4G035 AB06 AB22 AC06

Claims (17)

[Claims] 1. A step of taking drainage in a drainage tank containing oil into a casing vertically arranged in the drainage tank;
A process of feeding the introduced wastewater to aerate the wastewater in the casing, and subsequently discharging the wastewater after the aeration to the drainage tank from a discharge port at an upper portion of the casing located above the liquid level of the drainage tank. Aerating method, wherein, at the time of the ejection, ejection is performed by dispersing in a plurality of directions. 2. A step of taking the drainage in the drainage tank containing oil into a casing vertically arranged in the drainage tank;
Discharging the drained water after aeration to a drainage tank from a discharge port on an upper portion of the casing located above the liquid level of the drainage tank. An aeration method characterized by reducing the flow rate of drainage. 3. A step of taking drainage in a drainage tank containing oil into a casing vertically arranged in the drainage tank;
A step of feeding the introduced wastewater and aerating the same, and a step of subsequently discharging the wastewater after aeration to the drainage tank through a discharge port at the upper part of the casing located above the liquid level of the drainage tank. Discharging the liquid in a plurality of directions during the discharging, and reducing the flow velocity of the discharged wastewater before discharging and before dropping onto a liquid surface.
Aeration method. 4. An aeration apparatus installed in a drainage tank for storing drainage containing oil, wherein a casing forming a gas-liquid contact space therein, and a drainage above the drainage tank in the gas-liquid contact space. A suction unit for taking in air; and an air supply unit for sending air into the gas-liquid contact space. Drainage is taken into the gas-liquid contact space from the suction unit, and the gas-liquid contact space is provided by the air supply unit. And aerating the waste water to discharge the waste water from a discharge port at the upper part of the casing to a liquid surface of a drain tank, wherein the discharge port has a plurality of discharge ports. , Aeration equipment. 5. The aeration apparatus according to claim 4, wherein a baffle plate is provided on a front surface of the discharge port. 6. An aeration apparatus installed in a drainage tank for storing drainage containing oil, comprising: a casing forming a gas-liquid contact space therein; A suction unit for taking in air; and an air supply unit for sending air into the gas-liquid contact space. Drainage is taken into the gas-liquid contact space from the suction unit, and the gas-liquid contact space is provided by the air supply unit. And after the wastewater is aerated to aerate the wastewater, the wastewater is discharged from the discharge port at the upper part of the casing to the liquid surface of the drainage tank, and a baffle plate is provided in front of the discharge port. An aeration device characterized by the following. 7. The discharge port according to claim 4, wherein the discharge port is opened along a liquid surface of a drain tank.
The aeration apparatus according to claim 1. 8. The aeration apparatus according to claim 4, wherein the discharge port is open upward. 9. The aeration apparatus according to claim 8, wherein an outwardly protruding flange is provided at a periphery of the discharge port. 10. An aeration apparatus installed in a drainage tank for storing drainage containing oil, wherein a casing forming a gas-liquid contact space therein, and a drainage above the drainage tank in the gas-liquid contact space. A suction unit for taking in air; and an air supply unit for sending air into the gas-liquid contact space. Drainage is taken into the gas-liquid contact space from the suction unit, and the gas-liquid contact space is provided by the air supply unit. After aerating the waste water by aerating the inside, the waste water is discharged from a discharge port on an upper portion of the casing to a liquid surface of a drain tank, and the discharge port is
An aeration apparatus characterized by being provided on an upper part of a casing, extending in a horizontal direction, and formed on a side surface of a discharge passage whose extension end is closed. 11. The aeration apparatus according to claim 10, wherein a plurality of said discharge paths are provided. 12. The aeration apparatus according to claim 10, wherein a plurality of the discharge ports are formed in the discharge path. 13. The aeration apparatus according to claim 10, wherein at least a part of the upper surface of the discharge passage is open. 14. The aeration apparatus according to claim 13, wherein the discharge port has a slit shape formed in a vertical direction so as to reach the opening. 15. The discharge port according to claim 4, wherein an opening area of the discharge port is variable.
The aeration apparatus according to any one of 0, 11, 12, 13 and 14. 16. The drainage tank communicates with another drainage tank, and has another suction unit that can take in wastewater from inside the other drainage tank into the gas-liquid contact space. Claims 4, 5, 6, 7, 8, 9, 10, 11,
The aeration apparatus according to any one of 12, 13, 14 and 15. 17. The device according to claim 4, wherein said casing is detachable from a support member attached to a wall forming a drainage tub.
The aeration apparatus according to any one of 0, 11, 12, 13, 14, 15 and 16.