JP2001327844A - Agitator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an agitator for sufficiently and effectively agitating water to be treated while preventing the damage of a carrier. SOLUTION: A denitrification device 14 is used to agitate water to be treated incorporating a microorganism and containing a plurality of floatable carriers and contains a treating tank 141, a cylindrical member 145 arranged almost vertically in the water in the tank 141 and having a suction port to suck the water inward at the upper part and a discharge port to discharge the water from the inside at the lower part, a spiral 146 (spiral impeller) furnished to an almost vertically set rotating shaft 147 and an electric motor 148 to revolve the spiral 146 so that the water in the tank 141 is sucked in from the suction port of the cylindrical member 145, discharged from the discharge port, sent upward outside the member 145 and sent downward in the member 145.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique of a stirring device for stirring water to be treated, which includes a plurality of buoyant carriers containing microorganisms.

[0002]

2. Description of the Related Art Conventionally, in wastewater treatment, ammonia nitrogen in sewage is nitrified under aerobic conditions, and nitrate nitrogen,
Techniques for denitrifying nitrite nitrogen under anaerobic conditions and thereby removing nitrogen from wastewater are known. In particular,
Techniques using microorganisms (denitrifying bacteria) in a denitrification treatment apparatus are generally known, and these conventional techniques will be described below.

FIG. 10 shows a first conventional denitrification treatment apparatus 60.
FIG. 2 is a schematic cross-sectional view of a denitrification treatment device 60 for explaining the processing in FIG.

[0004] In the denitrification treatment apparatus 60 of the first conventional example, the aerated sewage flows into the cylindrical treatment tank 601 through the inflow port 602, and the water to be treated is temporarily removed for the denitrification treatment. The stored wastewater after the denitrification treatment and the denitrification (and the nitrogen gas generated by the microorganisms) are discharged through the outlet 603. The treated water contains countless carriers 606 containing microorganisms at a high density.
06 so that the strainer 6 does not flow out of the outlet 603.
04 is provided.

[0005] In the carrier 606, nitrogen gas is produced from nitrate nitrogen or nitrite nitrogen in the water to be treated by microorganisms, and the produced nitrogen gas moves the carrier 606 toward the water surface (in the directions of arrows 901 and 902). ) Surface.

The impeller 605, the electric motor 608 and the like are for submerging the carrier 606 floating as described above in water and agitating the water to be treated. The rotating shaft 607 supported by the bearings 609 and 610 is Electric motor 608
Is rotated in the rotation direction of the arrow 900 by the rotation shaft 607.
By the impeller 605 attached to the water, the water to be treated is turned into an arrow 901, an arrow 903, an arrow 905, and an arrow 907.
, The arrow 902, the arrow 904, the arrow 906,
It is circulated in the direction of arrow 908. (That is, the water to be treated forms a circulating flow that rises at the outer edge of the cylindrical treatment tank 601 and descends at the center.) FIG. 11 shows a second conventional example of a denitrification treatment apparatus 70. It is a typical sectional view of denitrification processing unit 70 for explaining processing.
(The second conventional example of the denitrification treatment apparatus 70 is described in more detail in Hirakawa Kogyosha, "Latest advanced water treatment technology from wastewater treatment to harmful substance removal technology".) In the denitrification treatment apparatus 70 of the prior art, the aerated sewage is stored in the treatment tank 71, and the carrier 80 is formed by the generation of nitrogen gas by microorganisms, similarly to the denitrification treatment apparatus 60 of the first prior art. Floats near the water surface.

[0007] Pump 78, drive channel 77, circulation channel 73
And the like are for submerging the carrier 80 which floats as described above in water to stir the water to be treated.
The direction of flow is determined in one direction by the pump 4, and the driving water (prevented by the screen 79 from intruding the carrier 80) flowing from the inlet 76 flows in the driving water channel 77 and the circulation water channel 73 by the pump 78 with an arrow 911. , Arrow 912
In the direction of The driving water having such a flow draws the water to be treated in the treatment tank 71 as circulating water from the inlet 72 of the circulating water channel 73 and circulates in the circulating water channel 73 in the directions of arrows 913, 914, and 915. Outlet 75
Drain from

In the denitrification treatment apparatus 60 of the first conventional example and the denitrification treatment apparatus 70 of the second conventional example, the microorganisms in the carrier are denitrified with stirring of the water to be treated as described above. Nitrogen in ammonia is removed as nitrogen gas, and low-cost and safe wastewater treatment is performed.

[0009]

However, according to the stirring of the water to be treated in the denitrification treatment apparatus 60 of the first conventional example (see FIG. 10), the carrier 606 is damaged by the rotating impeller 60. And the processing tank 601
When the carrier is deep, the floating carrier 606 is not sufficiently submerged and is not sufficiently stirred. (A plurality of impellers are required to perform sufficient agitation in the denitrification treatment apparatus 60, but these cannot be said to ensure that the buoyant carrier is submerged in the lower part of the treatment tank, and it is inefficient. .) Further, the above-described second conventional denitrification treatment apparatus 70 (FIG. 11).
According to the stirring of the to-be-processed water in (2), the carrier 80 may be accumulated around the screen 79 and the screen 79 may be closed, and the closed screen 70 hinders the circulation of the driving water, resulting in insufficient stirring. Further, structurally, the power of the pump 78 is not sufficiently utilized for the stirring, and the stirring here can be said to be originally inefficient.

The present invention has been made in view of the above problems, and has as its object to provide a stirring device capable of sufficiently efficiently stirring the water to be treated while preventing damage to the carrier. It is to provide a device.

[0011]

In order to achieve the above-mentioned object, a stirrer according to the present invention is a stirrer for stirring water to be treated, comprising a plurality of floating carriers containing microorganisms. .

The agitating device has a tank for storing the water to be treated and a suction port for sucking the water to be treated, which is provided substantially vertically in the water to be treated in the tank. A cylindrical member having a discharge port for discharging treated water from below, a spiral blade is formed, an impeller provided in the cylindrical member with the rotation axis substantially in the vertical direction, and an impeller provided in the tank. A rotation drive unit configured to rotate the impeller so that the water to be treated is sucked from the suction port of the cylindrical member and discharged from the discharge port.

In the above stirring apparatus, the cylindrical member and the impeller are integrally formed so that the outer side of the blade and the inner surface of the cylindrical member are in contact with each other, and are integrally rotated by the rotation driving means. can do.

Further, in the above-described stirring device, the cylindrical member is fixedly supported with respect to the tank such that the outside of the blade of the impeller and the inner surface of the cylindrical member are close to each other. be able to.

Further, in the above stirring device, the suction port of the cylindrical member is formed by opening an upper bottom surface of the cylindrical member, and the impeller has an upper portion projecting upward from the cylindrical member and having a blade in a rotational direction. May be rotatably provided at a position where the front edge of the water is near the surface of the water to be treated.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a denitrification apparatus according to one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing an entire configuration of a wastewater treatment facility 1 including a denitrification treatment apparatus 14 according to one embodiment of the present invention.

In the wastewater treatment equipment 1, first, contaminants (contaminants having a size of several mm or more) in the wastewater are removed in the sedimentation tank 11, and BOD (biological matter) in the wastewater is removed in the aeration tank 12. (Oxygen demand) is reduced, and ammonia nitrogen is nitrified. Thereafter, the sludge component is removed in the final sedimentation tank 13 and the denitrification treatment device 14 (the details are shown in FIGS. 2 to 4).
At, denitrification of nitrate nitrogen and nitrite nitrogen is performed,
The denitrified wastewater is circulated again to the final sedimentation tank 13 to further remove sludge components generated by the denitrification, whereby purified treated water is obtained.

In particular, the denitrification treatment apparatus 14 relates to the present invention, and hereinafter, the denitrification treatment apparatus 14 (and a modified denitrification treatment apparatus) will be described.

FIG. 2 is a perspective view showing the appearance of the denitrification treatment apparatus 14, and FIG. 3 is a schematic sectional view of the denitrification treatment apparatus 14 for explaining the processing in the denitrification treatment apparatus 14.

In the denitrification treatment apparatus 14 shown in FIGS. 2 and 3, sewage from the final settling tank flows into the cylindrical treatment tank 141 through the inlet 142 (continuously or batchwise).
Sewage flowing in for the denitrification treatment is temporarily stored as water to be treated, and after the denitrification treatment, the sewage after denitrification (and nitrogen gas generated by microorganisms) is discharged through the outlet 143. . The water to be treated contains a large number of carriers (of a size of about 1 cm cubic) containing microorganisms (denitrifying bacteria) at a high density. In the vicinity of the outlet 143, the carrier is prevented from flowing out from the outlet 143. Is provided with a strainer 144. (Here, it is assumed that the nitrogen gas is discharged through the outlet 143, but the nitrogen gas may also be released to the atmosphere from the open processing tank 141 as it is.) Nitrogen gas is generated from nitrate nitrogen or nitrite nitrogen in the treated water, and the carrier is directed toward the water surface by the generated nitrogen gas (arrow 801;
(In the direction of arrow 802).

The spiral (spiral blade) 146, the cylindrical member 145, the electric motor 148, etc. are used to submerge the floating carrier in the water and stir the water to be treated. The bearing 149 and the bearing 150 Is rotated in the direction of arrow 800 by an electric motor 148 (and a speed reducer not shown, the same applies hereinafter). Spiral 146 attached to rotating shaft 147 and cylindrical member 145 attached to spiral 146
Thereby, the flow path of the water to be treated is formed, and the water to be treated is circulated in the directions of arrows 801, 803, 805, and 806, and in the directions of arrows 802, 804, 805, and 807. . That is, the water to be treated in the treatment tank 141 rises outside the cylindrical member 145 and descends inside the cylindrical member 145 (the lower bottom surface which is sucked into the cylindrical member 145 and opened by using the opened upper bottom surface as a suction port). (Discharged from the inside of the cylindrical member 145 using the discharge port as a discharge port).

FIG. 4 is a view showing the position of the leading edge (upper end) of the spiral 146 when the water to be treated is stirred in the denitrification treatment apparatus 14.

The front edge of the spiral 146 is formed in a substantially radial direction assuming that the blade is circular when viewed from above, and the front edge of the spiral 146 is located above the surface of the water to be treated. This prevents the leading edge from contacting the carrier. Here, in particular, it is necessary to use the denitrifying bacteria anaerobically and to prevent the air from being mixed into the water to be treated, the spiral 146 is rotated at a position where the leading edge is slightly near the liquid surface.

In such a denitrification treatment apparatus 14 (see FIG. 3), the rotating spiral 146, the cylindrical member 14
5, the flow path of the water to be treated is formed, and the floating carrier is sunk, so that the denitrification treatment apparatus 60 of the first conventional example, in which these flow paths are not formed, The power loss of the electric motor 148 for rotating the spiral 146 and the cylindrical member 145 is small, as compared with the second conventional denitrification treatment apparatus 70 used, and efficient and reliable stirring is performed, and denitrification in the carrier is performed. Will be promoted.

Further, (the leading edge portion) of the spiral 146 and the carrier hardly come into contact with each other, so that the carrier can be prevented from being damaged. Further, it is necessary to arrange a strainer in the flow path of the circulating flow of the water to be treated. As a result, the efficiency of the stirring does not deteriorate due to the strainer clogging.

Further, the denitrification treatment device 14 is provided with a cylindrical member 245 of a denitrification treatment device 24 of a first modified example described later.
It does not include a member that has a high possibility of friction (such as a spiral and a spiral 246), and the denitrification treatment device 14 and the carrier can be used for a long life. It can be said that a special effect can be obtained.

The above-described denitrification treatment apparatus 14 is a denitrification treatment apparatus capable of performing stirring in a substantially similar manner, and may be modified as shown in FIGS.

FIG. 5 is a schematic sectional view of the denitrification processing apparatus 24 for explaining the processing in the denitrification processing apparatus 24 of the first modification.

The denitrification treatment device 24 of the first modification separates the spiral and the cylindrical member integrally formed by the above-mentioned denitrification treatment device 14, and treats the cylindrical member 245 by the support members 251 to 254. Fixedly supported in the tank 241,
Only the spiral 246 is rotated.

In the denitrification apparatus 24 of the first modification, similarly to the above-described denitrification apparatus 14, sewage flows into the treatment tank 241 through the inlet 242, and the water to be treated for the denitrification treatment is discharged. Sewage (and nitrogen gas) temporarily stored and denitrified after the denitrification treatment is discharged through the outlet 243. A large number of carriers are contained in the water to be treated, and a strainer 244 is provided near the outlet 243.

The rotating shaft 247 supported by the bearing 249 and the bearing 250 is rotated in the direction of an arrow 810 by the electric motor 248, and the spiral member 246 attached to the rotating shaft 247 and the cylindrical member 245 supported by the supporting members 251 to 254. Thereby, a flow path of the water to be treated is formed,
The water to be treated is circulated in the directions of arrows 811, 813, 815, and 816, and in the directions of arrows 812, 814, 815, and 817. (That is,
The water to be treated in the treatment tank 241 forms a circulating flow that rises outside the cylindrical member 245 and descends inside the cylindrical member 245. In such a denitrification treatment device 24, since the cylindrical member is not rotated together with the spiral unlike the denitrification treatment device 14, in addition to the effect of stirring by the denitrification treatment device 14 as described above, furthermore, The power for stirring can be reduced (the power for rotating the cylindrical member).

FIG. 6 is a schematic cross-sectional view of the denitrification processing apparatus 34 for explaining the processing in the denitrification processing apparatus 34 of the second modification. (In each of FIGS. 6 to 8, parts having the same functions as those of the denitrification processing apparatus 14 shown in FIG. 3 and the denitrification apparatus 24 shown in FIG. Detailed description of is omitted.
That is, each of the reference numerals 341 to 350 and the reference numerals 441 to 4
50, each of reference numerals 541 to 550
Each of the reference numerals 455 to 460 corresponds to each of the reference numerals 145 to 150. Also, arrow 821
826, arrows 831 to 843, and arrows 851 to 858 indicate the directions of the circulating flow of the water to be treated formed in the treatment tank, and arrows 820, 830, 840, and 850 indicate the directions of rotation of the rotating shafts. is there. The denitrification treatment device 34 of the second modification closes the lower bottom surface of the cylindrical member opened by the above-described denitrification treatment device 14, and further has one discharge port 826 near the lower bottom surface of the side surface of the cylindrical member. It has. The water to be treated in the cylindrical member 345 is discharged in a substantially horizontal direction by the discharge port 826 provided on the side surface, and the discharge direction of the discharge port 826 on this side surface can be changed within the rotation plane with the rotation of the cylindrical member 345. These denitrification treatment devices 3
In No. 4, the water to be treated sucked into the cylindrical member 345 is discharged while the direction is changed in one rotation plane, and the flow in the treatment tank is changed with the rotation.
4, the water to be treated is more effectively stirred.

FIG. 7 is a schematic sectional view of the denitrification processing apparatus 44 for explaining the processing in the denitrification processing apparatus 44 of the third modification.

The denitrification treatment apparatus 44 of the third modified example is such that a cylindrical or long cylindrical treatment tank is provided with two sets of spirals, a cylindrical member, and a member for rotating them. In these denitrification treatment devices 44, 2
Since the set of spirals and cylindrical members are rotated, the water to be treated is more effectively agitated as compared with the denitrification treatment device 14. In particular, here, directions 830 for rotating the rotating shaft 447 and directions 8 for rotating the rotating shaft 457 are described.
44 is reversed, thereby effectively agitating the water to be treated.

FIG. 8 is a schematic sectional view of the denitrification processing apparatus 54 for explaining the processing in the denitrification processing apparatus 54 of the fourth modification.

The denitrification processing apparatus 54 of the fourth modification is configured such that the lower bottom surface of the cylindrical member opened by the denitrification processing apparatus 14 described above (similar to the denitrification processing apparatus 34 of the second modification). It is closed, and has a plurality of outlets 551, outlets 552, and outlets 553 having different vertical positions on the side surface of the cylindrical member. In these denitrification treatment devices 54, the water to be treated sucked into the cylindrical member 545 is discharged while changing its direction in a plurality of rotation planes having different vertical positions, and flows in the treatment tank with the rotation. Is largely fluctuated, so that the water to be treated is more effectively stirred than in the denitrification treatment device 34. In addition to these, in the denitrification treatment apparatus 54, by changing the size of the discharge ports 551 to 553, it is possible to adjust so that the water to be treated is effectively stirred.

Although the denitrification treatment apparatus of the above embodiment is assumed to be used particularly in the wastewater treatment equipment 1 shown in FIG. 1, the denitrification of wastewater, sewage, and wastewater is performed to precipitate sludge components. It can also be used in other wastewater treatment equipment that separates and discharges the obtained treated water. FIG. 9 is a diagram showing an overall configuration of a wastewater treatment facility 2 as another example different from the above-described wastewater treatment facility 1, in which the denitrification treatment apparatus of the present invention is used.

In the wastewater treatment equipment 2, first, impurities are removed in a sedimentation tank 201, and BOD in wastewater is reduced in an aeration tank 202, and ammonia nitrogen is nitrified. Thereafter, the sludge component is removed in the intermediate sedimentation tank 203, and the denitrification of the nitrate nitrogen and the nitrite nitrogen is performed in the denitrification treatment device 204, and the denitrification is generated in the final sedimentation tank 205. The sludge component removed is removed, and purified treated water is obtained.

As such a denitrification treatment apparatus 204 of the wastewater treatment equipment 2, the above-described denitrification treatment apparatuses 14, 24, 3
4, 44 and 54 can be used.

Further, the denitrification treatment apparatus of the above embodiment is supposed to be used particularly in wastewater treatment equipment. A stirrer for agitating the water to be treated, including a plurality of carriers, is used in the production of foods and medical products and wastewater accompanying production, and in agricultural wastewater (tea cultivation, hydroponics, etc.). It can be used as a stirrer to promote microbial reactions (in the carrier).

[0042]

According to the first aspect of the present invention, the water to be treated is sucked from the upper suction port of the cylindrical member and discharged from the lower discharge port by the rotating spiral impeller. Thus, the flow path of the water to be treated is formed, and the water to be treated including the buoyant carrier is efficiently stirred over the upper and lower portions in the tank.

According to the second aspect of the present invention, the water to be treated is sucked from the upper suction port of the cylindrical member and discharged from the lower discharge port by the integral cylindrical member and the spiral impeller which are rotated. The flow path of the water to be treated is formed by the integral cylindrical member and the impeller, and the water to be treated including the buoyant carrier is agitated sufficiently and efficiently over the upper and lower portions in the tank. Become. Further, since there is no friction portion between the cylindrical member and the impeller, it can be said that the stirring device and the carrier are used for a long life.

According to the third aspect of the present invention, the water to be treated is sucked from the upper suction port of the cylindrical member by the rotating spiral impeller in the cylindrical member fixedly supported in the tank. Since the water is discharged from the lower discharge port, a flow path of the water to be processed is formed by the cylindrical member and the impeller, and the processing target including the buoyant carrier is sufficiently efficiently spread over the upper and lower portions in the tank. The water will be stirred. Further, since only the impeller is rotated, it can be said that the rotation is performed with smaller power.

According to the fourth aspect of the present invention, the front edge is further rotated near the water surface, so that the contact between the front edge and the carrier is prevented, and the carrier is sufficiently efficiently prevented from being damaged. The to-be-processed water will be stirred.

According to the fifth aspect of the present invention, since the water to be treated is discharged in a substantially horizontal direction while changing its direction in one rotation plane, the flow in the tank is fluctuated with the rotation. The water to be treated is effectively stirred.

According to the sixth aspect of the present invention, the water to be treated is discharged in a substantially horizontal direction while changing its direction in a plurality of rotation planes having different vertical positions. The flow is more greatly fluctuated, and the water to be treated is more effectively agitated.

According to the seventh aspect of the present invention, since a plurality of sets of the impeller, the cylindrical member, and the rotary drive means are used in one tank, the present invention is more effective over the upper and lower portions in the tank. The to-be-treated water containing the buoyant carrier is stirred.

[Brief description of the drawings]

FIG. 1 is a diagram showing an entire configuration of a wastewater treatment facility 1 including a denitrification treatment apparatus 14 according to one embodiment of the present invention.

FIG. 2 is a diagram showing an appearance of a denitrification treatment device 14;

FIG. 3 is a schematic cross-sectional view of the denitrification processing apparatus for explaining the processing in the denitrification processing apparatus.

FIG. 4 is a diagram showing the position of the leading edge of a spiral 146 when the water to be treated is stirred in the denitrification treatment device 14;

FIG. 5 is a schematic cross-sectional view of a denitrification processing device 24 for describing processing in the denitrification processing device 24 of the first modification.

FIG. 6 is a schematic cross-sectional view of a denitrification processing device for describing processing in the denitrification processing device according to a second modified example.

FIG. 7 is a schematic cross-sectional view of a denitrification processing device 44 for describing processing in a denitrification processing device 44 of a third modification.

FIG. 8 is a schematic cross-sectional view of a denitrification processing device for describing processing in a denitrification processing device according to a fourth modification.

FIG. 9 is a diagram showing an overall configuration of a wastewater treatment facility 2 as another example different from the wastewater treatment facility 1, in which the denitrification treatment apparatus of the present invention is used.

FIG. 10 is a schematic cross-sectional view of a denitrification processing apparatus 60 for describing processing in a first conventional example of a denitrification processing apparatus 60.

FIG. 11 is a schematic cross-sectional view of a denitrification processing apparatus 70 for explaining processing in a second conventional example of a denitrification processing apparatus 70.

[Explanation of symbols]

Reference Signs List 1 wastewater treatment equipment 11 first sedimentation tank 12 aeration tank 13 final sedimentation tank 14 denitrification treatment device 141 treatment tank 142 inflow port 143 outflow port 144 strainer 145 cylindrical member 146 spiral (helical blade) 147 rotating shaft 148 motor 149, 150 Bearing 24, 34, 44, 54 Denitrification treatment device 241, 341, 441, 541 Treatment tank 242, 342, 442, 542 Inlet 243, 343, 443, 543 Outlet 244, 344, 444, 544 Strainer 245, 345, 445, 455, 545 cylindrical member 246, 346, 446, 456, 546 spiral 247, 347, 447, 457, 547 rotating shaft 248, 348, 448, 458, 548 motor 249, 250, 349, 350, 449; 450, 4
59, 460, 549, 550 Bearings 251 to 254 Supporting members 351, 551 to 553 Horizontal discharge ports 800, 810, 820, 830, 840, 844, 8
50 Arrows indicating rotation directions of rotation shafts 801 to 807, 811 to 817, 821 to 826, 8
31 to 843, 851 to 858 Arrows indicating the direction of circulating water flow 2 Wastewater treatment equipment 201 First sedimentation tank 202 Aeration tank 203 Intermediate sedimentation tank 204 Denitrification treatment equipment 205 Final sedimentation tank

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[Procedure amendment]

[Submission date] June 1, 2000 (2006.1)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

[0009]

However, according to the stirring of the water to be treated in the denitrification treatment apparatus 60 (see FIG. 10) of the first conventional example, the carrier 606 is damaged by the rotating impeller 605 . Susceptible, and the processing tank 60
When the number 1 is deep, the carrier 606 that has floated is not sufficiently submerged and is not sufficiently stirred. (A plurality of impellers are required to perform sufficient stirring in the denitrification treatment device 60,
These cannot be said to be the ones in which the buoyant carrier is surely submerged in the lower part of the processing tank, and can be said to be inefficient. In addition, the above-described second conventional denitrification treatment apparatus 70 (FIG. 11)
According to the stirring of the to-be-processed water in (1), the carrier 80 may be accumulated around the screen 79 and the screen 79 may be closed, and the closed screen 79 may impede the circulation of the driving water, resulting in insufficient stirring. Further, structurally, the power of the pump 78 is not sufficiently utilized for the stirring, and the stirring here can be said to be originally inefficient.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

[0011]

In order to achieve the above-mentioned object, a stirrer according to the present invention is a stirrer for stirring water to be treated, comprising a plurality of floating carriers containing microorganisms. . Here, the “buoyancy” of the carrier is, for example,
Nitrate nitrogen or nitrite nitrogen in treated water
It is due to nitrogen gas produced by microorganisms.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C02F 3/30 ZAB C02F 3/30 ZABA

Claims (7)

[Claims] 1. A stirrer for stirring water to be treated, comprising a plurality of buoyant carriers containing microorganisms, a tank for storing the water to be treated, and a substantially vertical direction in the water to be treated in the tank. A cylindrical member having a suction port for sucking the water to be treated therein at an upper portion thereof and a discharge port for discharging the water to be treated therein from a lower portion thereof, and a helical blade formed therein. An impeller provided in the cylindrical member with the rotation axis substantially in a vertical direction, and the impeller rotating so that water to be treated in the tank is sucked in from the suction port of the cylindrical member and discharged from the discharge port. A stirrer, comprising: a rotation drive unit for causing the stirrer to rotate. 2. The cylindrical member and the impeller are integrally formed such that an outer surface of the blade and an inner surface of the cylindrical member are in contact with each other, and are integrally rotated by the rotation driving means. Stirrer. 3. The stirrer according to claim 1, wherein the cylindrical member is fixedly supported with respect to the tank such that an outer surface of the blade of the impeller and an inner surface of the cylindrical member are close to each other. 4. A suction port of the cylindrical member is formed by opening an upper bottom surface of the cylindrical member, and the impeller has an upper portion projecting upward from the cylindrical member and covering a front edge of the blade in a rotation direction. The stirrer according to any one of claims 1 to 3, wherein the stirrer is rotatably provided at a position near a surface of the treated water. 5. The stirring device according to claim 1, wherein a lower bottom surface of the cylindrical member is closed, and a discharge port of the cylindrical member is provided near a lower bottom surface of a side surface of the cylindrical member. 6. The stirrer according to claim 1, wherein the lower bottom surface of the cylindrical member is closed, and a plurality of outlets of the cylindrical member are provided at different positions in the vertical direction on the side surface of the cylindrical member. . 7. The stirring device according to claim 1, comprising a plurality of the impellers, a plurality of corresponding cylindrical members, and a plurality of corresponding rotation driving means.