JP4060484B2 - Underwater stirring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to an underwater agitation apparatus used for treating sewage such as sewage and industrial wastewater, and more particularly to an underwater agitation apparatus suitably used for a treatment tank having a large depth capable of treating a large amount of sewage. .
[0002]
[Prior art]
When treating sewage such as sewage by the activated sludge method, etc., a plurality of treatment tanks with a water depth of about 5 m are usually used, and when treating sewage or activated sludge mixed water in the treatment tank, The treatment tank is subjected to anaerobic stirring, oxygen-free stirring, or aerobic stirring.
[0003]
Recently, in order to increase the amount of sewage treated in the treatment tank, the sewage tank is deepened to a large depth of about 10 to 20 m, or a carrier carrying microorganisms that promote the sewage treatment reaction is About 7% to 20% is charged and processed. In such a deepened treatment tank or a treatment tank in which a large amount of carrier is charged, it is important to reliably stir the sewage or the activated sludge mixed water in the treatment tank, particularly at the bottom of the treatment tank, It is necessary to reliably stir the sewage or the activated sludge mixed water.
[0004]
Conventionally, an underwater stirring apparatus as shown in FIG. 4 is used in a deepened processing tank. In this underwater agitation apparatus, a suction guide cylinder 64 is vertically installed at the bottom of the processing tank 61, and a stirrer main body 62 is connected to a pair of guides above the suction guide cylinder 64, which is the middle layer of the processing tank 61. The pipe 63 is installed so that it can be raised and lowered. In such an underwater agitation apparatus, the sewage or activated sludge mixed water in the bottom of the treatment tank 61 is flowed to the middle layer part and the upper layer part by the stirrer main body 62, thereby mixing the sewage or activated sludge in the treatment tank 61. Water is stirred and mixed. Since the stirrer main body 62 is installed at a relatively shallow position on the suction guide cylinder 64, a high-pressure air supply device should be used when stirring sewage or activated sludge mixed water under aerobic conditions. In addition, air can be supplied to the stirrer main body 62 with a normally used aeration blower or the like, and air can be mixed with the sewage water stirred by the stirrer 62.
[0005]
However, in such an underwater agitation apparatus, when the activated sludge concentration of the activated sludge mixed water is very high, or when the sewage is treated with a carrier on which microorganisms are supported, the suction tank 64 is used to treat the sewage. It is difficult to sufficiently suck the activated sludge and the carrier having a high concentration at the bottom of 61 and flow them to the middle layer and the upper layer, and there is a possibility that the activated sludge, the carrier and the like are precipitated at the bottom of the treatment tank 61.
[0006]
In addition, as shown in FIG. 5, there is an example of using an underwater agitation apparatus in which the agitator body 62 is installed at the bottom of the deepened treatment tank 61. In such an underwater agitation apparatus, the sewage or activated sludge mixed water at the bottom of the treatment tank 61 is stirred relatively well by the stirrer main body 62, but the sewage or activated sludge mixed in the upper layer part of the treatment tank 61. It is difficult to sufficiently stir water, and there is a possibility that a difference in the concentration of activated sludge or a difference in the concentration of the carrier may occur in the upper layer portion and the lower layer portion of the treatment tank 61. Moreover, in such an underwater agitation device, when the sewage is agitated under aerobic conditions, the air is supplied at a high pressure so that air can be supplied into the high-pressure sewage at the bottom of the deep treatment tank 61. There is also a problem that an air supply device that can supply air is required.
[0007]
Japanese Patent Laid-Open No. 6-3036690 discloses that a lower end of a vertical pipe disposed in a vertical state in a treatment tank is curved in a U shape, and an end of the vertical pipe curved in a U shape is Stirring air diffuser provided with a pump device that discharges sewage or activated sludge mixed water over the entire circumference of the direction, and a supply section for supplying air to the sewage or activated sludge mixed water flowing down in the vertical tube Is disclosed. In such an agitating and agitating device, the lower end of the vertical tube is curved in a U shape, and the pump device is detachably attached to the upwardly facing end surface of the lower end that is curved in a U shape. In addition, only the pump device can be lifted, and operations such as maintenance of the pump device can be facilitated. However, when the lower end portion of the vertical tube is curved in a U shape in this way, the pump device is disposed at an appropriate interval with respect to the bottom surface of the processing tank. As a result, a part of the discharge flow from the pump device is discharged from the bottom of the treatment tank, and there is a possibility that the sewage or the activated sludge mixed water at the bottom of the treatment tank cannot be reliably stirred.
[0008]
In addition, as shown in FIG. 6, an underwater agitation device has been developed in which a pump device 66 is provided at the lower end portion of a lead-in pipe 65 arranged vertically in the processing tank 61. In this underwater agitation device, sewage or activated sludge mixed water is sucked into the draw-in pipe 65 by the pump device 66, and sewage flows down in the draw-in pipe 65 from the air supply unit 67 provided in the middle of the draw-in pipe 65. Alternatively, air is supplied to the activated sludge mixed water, and the mixed water or activated sludge mixed water is discharged from the opening at the bottom of the treatment tank 61.
[0009]
In this underwater agitation device, a high-pressure air supply device is provided so that air is sucked to the bottom of the treatment tank 61 together with the sewage or the activated sludge mixed water by the pump device 66 installed at the bottom of the treatment tank 61. Instead, the air is supplied to the bottom of the treatment tank 61. Then, the sewage mixed with air or the activated sludge mixed water is discharged from the lower end of the drawing pipe 65, whereby the sewage or the activated sludge mixed water is efficiently stirred and aerated at the bottom of the treatment tank 61. can do.
[0010]
[Problems to be solved by the invention]
However, in such an underwater agitation device, air can be sent to the bottom of the treatment tank 61 and diffused without providing a high-pressure air supply device, and the sewage or activated sludge mixed water at the bottom of the treatment tank 61 can be diffused. On the other hand, since the pump device 66 that plays a role of sucking sewage or activated sludge mixed water and air is installed in the lower part of the vertically arranged lead-in pipe 65, There is a problem that maintenance work of the pump device 66 is not easy. In particular, when the depth of the processing tank is large, it is extremely difficult to lift the pump device 66 integrated with the drawing pipe 65.
[0011]
The present invention is to solve such a problem, the purpose is to be able to reliably stir the sewage or activated sludge mixed water at the bottom, even in a treatment tank having an increased depth, And it is providing the underwater stirring apparatus which can perform a maintenance operation | work easily.
[0012]
[Means for Solving the Problems]
The underwater agitation device of the present invention is arranged in the vertical direction so that the sewage or the activated sludge mixed water flows into the reaction tank for treating the sewage or the activated sludge mixed water from the suction port at the upper end, and is disposed at the lower end. A vertical pipe having a curved portion that is curved in the horizontal direction, and sewage or activated sludge mixed water that is detachably provided to the curved portion of the vertical pipe and that flows into the vertical pipe when connected to the curved portion A water flow generator that sucks in and flows horizontally, and a discharge body to which the water flow generator is detachably connected so as to discharge the sewage or activated sludge mixed water flowing in the water flow generator in a substantially horizontal direction The water flow generator includes a cylindrical tube connected in a concentric state to the curved portion of the vertical tube, a drive unit attached to the tube, and a drive thereof Impeller mounted on the machine drive shaft In the inclined state, the end surface of the tubular body facing the guide surface of the curved portion of the vertical tube in the tubular body sequentially protrudes toward the curved portion side toward the upper side along the guide surface of the curved portion. The other end surface of the tube body is formed in an inflow side inclined surface facing obliquely downward, and gradually goes away from the curved portion as it goes upward along the guide surface of the discharge body on the water flow generator side. Inclined so as to protrude and formed on the outflow side inclined surface facing obliquely downward, the vertical pipe and the discharge body are respectively installed on the bottom surface of the reaction tank, and the water flow generator moves up and down in the reaction tank In the water flow generator, the inflow side inclined surface is joined to the guide surface of the curved portion by lowering the inside of the reaction tank, and the outflow side inclined surface is the guide surface of the discharge body. Japanese to be joined to To.
[0014]
Air is supplied into the sewage or the activated sludge mixed water flowing down in the vertical pipe.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partially broken front view showing an example of an embodiment of an underwater stirring device of the present invention. The underwater agitation device is provided in a reaction tank 50 having a large depth provided for purifying sewage such as sewage or activated sludge mixed water, and a vertical pipe disposed in a vertical state in the reaction tank 50. 10. The lower end portion of the vertical tube 10 is a curved portion 11 curved in the horizontal direction, and the curved portion 11 is installed on the bottom surface of the reaction tank 50. The upper end of the vertical pipe 10 is provided with a bell mouth-shaped suction port 12 whose diameter gradually increases toward the upper side. The upper end surface of the suction port 12 is more than the surface of the sewage or the activated sludge mixed water. Is located in the upper layer part slightly below. Therefore, the sewage or the activated sludge mixed water in the reaction tank 50 flows into the vertical pipe 10 from the suction port 12.
[0016]
An air supply unit 13 is provided in the middle of the vertical tube 10 in the vertical direction. The air supply unit 13 includes a casing 13b that surrounds the outer peripheral surface of the vertical pipe 10, and an air supply pipe 13a that is connected to the casing 13b so as to supply air into the casing 13b. The upper end portion of the pipe 13a is drawn upward from the water surface so as to be positioned above the water surface of the sewage or activated sludge mixed water in the reaction tank 50. A large number of through holes are provided in the outer peripheral surface of the vertical pipe 10 surrounded by the casing 13b so as to communicate with the inside of the casing 13b, and the air supplied into the casing 13b through the air supply pipe 13a. Is supplied into the vertical tube 10 through the through hole.
[0017]
A plurality of hollow air diffuser members arranged radially are provided in the vertical tube 10, and the air supplied into the casing 13b is blown into the air diffuser members, respectively. Alternatively, air may be supplied into the vertical tube 10 from the through holes provided respectively.
[0018]
The end surface of the curved portion 11 provided at the lower end portion of the vertical tube 10 is inclined slightly upward with respect to the vertical so that the lower end portion protrudes laterally from the upper end portion and is directed obliquely upward. It is a guide surface 11a.
[0019]
A discharge body 30 installed on the bottom surface of the reaction vessel 50 is installed on the curved portion 11 of the vertical tube 10 with an appropriate interval in the horizontal direction. And between the curved part 11 of the vertical pipe 10, and the discharge body 30, the water flow generator 20 is provided with respect to the curved part 11 and the discharge body 30 of the vertical pipe 10, respectively so that attachment or detachment is possible. The water flow generator 20 can move up and down along a pair of guide pipes 51 disposed inside the reaction vessel 50.
[0020]
The water flow generator 20 includes a cylindrical tube body 21 that is concentrically connected to the curved portion 11 of the vertical tube 10 and a drive unit 22 that is fixedly mounted in the tube body 21. And an impeller 23 attached to the drive shaft of the drive unit 22.
[0021]
When the tube body 21 is arranged in a horizontal state, the end surface facing the guide surface 11a of the bending portion 11 of the longitudinal tube 10 is sequentially curved as it goes upward along the guide surface 11a of the bending portion 11. In an inclined state protruding toward the portion 11 side, the inflow side inclined surface 21a faces obliquely downward. The other end surface of the tubular body 21 is inclined so as to protrude in a direction away from the curved portion 11 as it goes upward, thereby forming an outflow side inclined surface 21b directed obliquely downward. And this outflow side inclined surface 21b is joined to the discharge body 30 installed on the bottom face of the reaction tank 50. As shown in FIG.
[0022]
The drive unit 22 arranged inside the tube body 21 is attached in a state where the drive shaft is along the axis of the tube body 21, and the drive shaft of the drive unit 22 protruding to the curved portion 11 side of the tube body 10. Further, an impeller 23 having a plurality of blades is attached. The impeller 23 is rotated by the driving machine 22 to suck the sewage or the activated sludge mixed water in the vertical pipe 10 and send it out into the discharge body 30 from the outflow side inclined surface 21b located on the far side of the bending portion 11. It is like that.
[0023]
FIG. 2 is a plan view of the discharge body 30 installed on the bottom surface of the reaction vessel 50. Guide pipes 51 mounted in the reaction tank 50 in a substantially vertical state are provided on the left and right sides of the pipe body 21 of the water flow generator 20, respectively. Guide members 24 that are slidably engaged with the guide pipe 51 are provided.
[0024]
As shown in FIG. 1, a pair of suspension engagements are provided on the upper portion of the pipe body 21 of the water flow generator 20 detachably provided between the curved portion 11 of the vertical pipe 10 and the discharge body 30. The portions 21c are provided at appropriate intervals in the axial direction, and each end portion of the hanging tool 41 is attached to each hanging engaging portion 21c. The hanging tool 41 has three ends, a pair of ends are engaged with the hanging engaging portion 21c, and the other end is attached to the lower end of the hanging rope 40. It has been. The water flow generator 20 is arranged along the guide pipe 51 with the pipe body 21 in a horizontal state by the suspension rope 40 in a state where each guide member 24 of the pipe body 21 is engaged with the guide pipe 51. Thus, the inside of the reaction tank 50 is moved up and down.
[0025]
The discharge body 30 to which the water flow generator 20 is joined has a short cylindrical inflow pipe portion 31 that is in a horizontal state so as to be joined concentrically with the pipe body 21 of the water flow generator 20. The end surface of the inflow pipe portion 31 on the side of the water flow generator 20 is inclined such that the lower portion protrudes toward the water flow generator 20 from the upper portion, and is a guide surface 31a facing obliquely upward. When 20 tube bodies 21 become horizontal, they are configured to be parallel to the outflow side inclined surface 21b of the tube body 21.
[0026]
A side portion of the discharge body 30 located on the far side of the water flow generator 20 is a discharge portion 32 that is flattened in a fan shape that spreads to the left and right sides with respect to the inflow pipe portion 31. The upper surface of the discharge section 32 is inclined so as to be sequentially positioned on the lower side as the distance from the inflow pipe section 31 is increased, and a plurality of discharge ports 32a are formed at the far end of the inflow pipe section 31 in the discharge section 32. Are arranged side by side in the horizontal direction. The axis of each discharge port 32a extends radially in the left-right direction with respect to the axis of the inflow pipe portion 31a. Further, between the adjacent discharge ports 32a, guide grooves 32b opened upward and in the discharge direction of the discharge ports 32a are respectively in a state substantially along the axial direction of the discharge ports 32 on both sides. Is provided. In addition, each guide groove 32b is good also as a structure opened instead of the structure opened upwards.
[0027]
In the underwater agitation apparatus having such a configuration, the vertical tube 10 and the discharge body 30 are respectively installed in advance on the bottom surface in the reaction tank 50, and the hanging rope 40 is attached to the vertical tube 10 and the discharge body 30. The water flow generator 20 suspended by the suspension 41 is lowered in the sewage or activated sludge mixed water in the reaction tank 50, and the tube body 21 is fitted between the vertical tube 10 and the discharge body 30. The In this case, the pipe body 21 of the water flow generator 20 has the inflow side inclined surface 21a guided by the guide surface 11a in the curved portion 11 of the vertical pipe 10, and the outflow side inclined surface 21b of the pipe body 21 is a discharge body. It is guided by the guide surface 31 a in the inflow pipe portion 31 of 30 and is sequentially inserted between the curved portion 11 of the vertical pipe 10 and the discharge body 30. The inflow side inclined surface 21 a of the tube body 20 is joined in alignment with the guide surface 11 a in the curved portion 11 of the vertical tube 10, and the outflow side inclined surface 21 b of the tube body 21 is connected to the inflow tube of the discharge body 30. The water flow generator 20 is connected to the curved portion 11 of the vertical pipe 10 and the discharge body 30 in a concentric state by being joined to the guide surface 31a in the portion 31 in an aligned state.
[0028]
If it will be in such a state, the impeller 23 arrange | positioned in the pipe 21 will be rotationally driven by the drive machine 22 of the water flow generator 20. FIG. As a result, the sewage or activated sludge mixed water that has flowed into the vertical pipe 10 is sucked by the water flow generator 20 and flows downward in the vertical pipe 10, and the sewage or activated sludge mixed water in the reaction tank 50. Is sucked into the vertical tube 10 from the suction port 12 provided at the upper end of the vertical tube 10 and flows down in the vertical tube 10. In this case, when the sewage or the activated sludge mixed water flows down the air supply unit 13 provided in the middle of the vertical tube 10, the air supply tube 13a connected to the casing 13b is placed in the casing 13b of the air supply unit 13. When air is fed from the air, air is mixed into the sewage or the activated sludge mixed water passing through the air supply unit 13 as bubbles. The sewage mixed with air or the activated sludge mixed water is sucked into the water flow generator 20 through the curved portion 11 of the vertical pipe 10, and is sent out into the inflow pipe portion 31 of the discharge body 30 by the water flow generator 20. The
[0029]
The sewage or activated sludge mixed water that has flowed into the inflow pipe portion 31 of the discharge body 30 together with the air flows from the inflow pipe portion 31 into the discharge portion 32 spreading in a fan shape in the left-right direction, and passes through each discharge port 32a. Thus, the liquid is discharged in a substantially horizontal state slightly downward. The air-mixed sewage or the activated sludge mixed water discharged from each discharge port 32a flows along the bottom surface of the reaction tank 50 close to each discharge port 32a.
[0030]
In this case, since the adjacent discharge ports 32a are divided by the guide grooves 32b between the discharge ports 32a, the sewage or activated sludge mixed water discharged from the discharge ports 32a is It becomes a beam-like flux, and it flows over a wide range with mixed air with little attenuation to a long distance. In addition, since the guide grooves 32b located between the discharge ports 32a are open upward and in the discharge direction of the sewage or the activated sludge mixed water, the guide grooves 32b together with the main jets discharged from the discharge ports 32a. Therefore, the generation of Karman vortices with respect to the beam-like discharge main jet is prevented. Thereby, the damping effect | action of the discharge flow from each discharge port 32a is reduced, and a discharge flux can be reached to a far distance. As a result, the sewage or activated sludge mixed water at the bottom of the reaction tank 50 is reliably stirred over a wide range, and the sewage or activated sludge mixed water is efficiently treated.
[0031]
As described above, the underwater stirring device of the present invention can reliably stir the sewage or the activated sludge mixed water at the bottom of the reaction tank 50, and the sewage or the activated sludge mixed water that flows downward in the vertical pipe 10 Since air is mixed in as bubbles from the casing 13b of the air supply unit 13 and discharged together with the sewage or the activated sludge mixed water stirred over a wide range, it can be diffused over a wide range. .
[0032]
The air supply unit 13 for supplying air into the vertical tube 10 is provided in a relatively shallow portion so that the bubbles reach the bottom of the reaction tank 50 by riding on the lower precipitation flow in the vertical tube 10. Therefore, a high-pressure air supply device is not required, and stirring can be performed with high efficiency under aerobic conditions at the deep bottom of the deep reaction tank 50. As a result, it can be suitably used for treatment of sewage or activated sludge mixed water with activated sludge, treatment of sewage or activated sludge mixed water by nitrification and denitrification using a carrier on which microorganisms are supported, and the like.
[0033]
In addition, when the water flow generator 20 is maintained, the water flow generator 20 is pulled up along the guide pipes 51 by the hanging rope 40. When the maintenance or the like of the water flow generator 20 is completed, the water flow generator 20 is lowered along the guide pipe 51 in the sewage or activated sludge mixed water in the reaction tank 50, and as described above, the vertical pipe 10 Are guided by the guide surface 11a of the curved portion 11 and the guide surface 31a of the discharge body 30, respectively, and are connected to the curved portion 11 and the discharge body 30 of the longitudinal tube 10, respectively. Since the water flow generator 20 has a simple configuration in which the drive unit 22 and the impeller 23 are disposed inside the detachable tube body 21, it is lightweight and easy to handle.
[0034]
In addition, when purifying the sewage in the reaction tank 50 or the activated sludge mixed water under anaerobic or oxygen-free conditions, it is not necessary to provide the air supply unit 13 for the vertical tube 10. Also in this case, the sewage or the activated sludge mixed water flowing down in the vertical pipe 10 by the water flow generator 20 is stirred to a wide range by the discharge body 30 without being attenuated. Sewage or activated sludge mixed water can be efficiently purified by anaerobic or oxygen-free conditions.
[0035]
Moreover, in the said embodiment, although the discharge body 30 was installed on the bottom face of the reaction tank 50 and comprised so that attachment or detachment with respect to the water flow generator 20 was carried out, the discharge body 30 is set on the bottom face of the reaction tank 50. You may make it raise / lower integrally with the water flow generator 20 as a state connected with the water flow generator 20 without installing.
[0036]
Furthermore, when the reaction tank 50 is long in the bending direction of the vertical tube 10 and the dimension in the width direction orthogonal to that direction is small, as shown in FIG. 3, the discharge flow does not spread to the left and right sides, You may make it use the discharge body 30 which came to be able to discharge sewage or activated sludge mixed water along one direction.
[0037]
【The invention's effect】
In the underwater agitation apparatus of the present invention, the water flow generator is detachably provided to the curved portion provided at the lower end portion of the vertical pipe as described above, and the water flow generator connected to the vertical pipe Since the sewage or the activated sludge mixed water in the pipe is sucked and discharged from the discharge body along the bottom surface of the reaction tank, even in a deep reaction tank, The activated sludge mixed water can be reliably stirred and purified. In addition, since the water flow generator can be easily installed and removed, maintenance and other operations can be easily performed. Furthermore, since air can be supplied to the bottom of the reaction tank without providing a special device, the sewage or the activated sludge mixed water at the bottom of the reaction tank having a large depth can be reliably aerated over a wide range. Stir processing can be performed.
[Brief description of the drawings]
FIG. 1 is a partially broken front view showing an example of an embodiment of an underwater stirring device of the present invention.
FIG. 2 is a plan view of a discharge body provided in the underwater stirring device.
FIG. 3 is a plan view showing another example of the embodiment of the underwater stirring device of the present invention.
FIG. 4 is a front view showing an example of a conventional underwater stirring apparatus.
FIG. 5 is a front view showing another example of a conventional underwater stirring apparatus.
FIG. 6 is a schematic configuration diagram showing still another example of a conventional underwater stirring apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Vertical pipe 11 Curved part 11a Guide surface 12 Suction port 13 Air supply part 13c Air suction pipe 20 Water flow generator 21 Tube 21a Inflow side inclined surface 21b Outflow side inclined surface 21c Hanging member 22 Drive machine 23 Impeller 30 Discharge body 31 Inflow pipe portion 32 Discharge portion 32a Discharge port 32b Guide groove 40 Hanging rope 50 Reaction tank

Claims (2)

In the reaction tank that treats sewage or activated sludge mixed water, it is arranged vertically so that sewage or activated sludge mixed water flows from the suction port at the upper end, and a curved portion that curves in the horizontal direction at the lower end. A longitudinal tube having,
A water flow generator that is detachably attached to the curved portion of the vertical pipe and sucks the sewage or activated sludge mixed water flowing into the vertical pipe and flows in the horizontal direction when connected to the curved portion. ,
In the underwater agitation device comprising a discharge body to which the water flow generator is detachably connected so as to discharge the sewage flowing in this water flow generator or the activated sludge mixed water in a substantially horizontal direction,
The water flow generator includes a cylindrical tube connected concentrically to the curved portion of the vertical tube, a drive unit attached to the tube, and an impeller attached to a drive shaft of the drive unit And
The end face of the tubular body that faces the guide surface of the curved portion of the vertical pipe is inclined downward and in an inclined state that sequentially protrudes toward the curved portion side as it goes upward along the guide surface of the curved portion. Formed on the inflow side inclined surface,
The other end surface of the tube body is inclined so as to protrude in a direction away from the curved portion as it goes upward along the guide surface of the discharge body on the water flow generator side, and the outflow directed obliquely downward. Formed on the side inclined surface,
The vertical pipe and the discharge body are respectively installed on the bottom surface of the reaction tank, and the water flow generator is moved up and down in the reaction tank, and the water flow generator is moved down in the reaction tank. Accordingly, the inflow side inclined surface is joined to the guide surface of the curved portion, and the outflow side inclined surface is joined to the guide surface of the discharge body .   The underwater agitation device according to claim 1, wherein air is supplied into the sewage or activated sludge mixed water flowing down in the vertical pipe.

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