JP2004237203A - Stirring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently perform stirring mixing by generating a strong rotating flow around a vertical axis and turbulence in the up and down directions inside a rotating cylinder, and to prevent the occurrence of the retention places of a liquid by generating convection currents in the up and down directions inside a stirring tank. <P>SOLUTION: The inside of a stirring tank 12 is provided with a rotating cylinder 11 having many small holes 11B on a circumferential wall 11A in a longitudinal direction, the center of the rotating cylinder is provided with a liquid feed tube 13, the liquid feed tube 13 is provided with a branch pipe 14 extending to the radial direction of the rotating cylinder 11 in a multistage, the branch pipe 14 is provided with a nozzle 15 in the direction crossed with the radial direction of the rotating cylinder 11, the liquid feed pipe 13 is connected with the discharge port 17 of a pump 16, and further, an injection port 20 for injecting the liquid to be treated and a feed port 28 for feeding a flocculant into the rotating cylinder 11 are provided. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a stirring device for stirring a liquid in a tank.
[0002]
[Prior art]
Examples of a method for stirring the liquid in the tank include stirring with a stirring blade or a stirring rod, aeration, and stirring with a liquid flow of a pump.
Such a stirring method is selected depending on the properties and use of the liquid to be stirred.
For example, like a wastewater treatment facility that treats wastewater from construction work, after adding a coagulant to turbid raw water, it is stirred and mixed to coagulate and sediment the turbid substance, and separated into clear treated water and sludge. In the case of performing the treatment, a stirring method using a liquid flow of a pump is often used.
[0003]
Conventionally, as a stirring device using a liquid flow of a pump, a pump is installed in a stirring tank, a connecting pipe is connected to a discharge port of the pump, a cylindrical header is provided at the top of the connecting pipe, and the header is directed in all directions. There is a device provided with a discharge pipe (see Patent Document 1).
In addition, a vertically installed hollow shaft is provided in the stirring tank and connected to the discharge port of the pump, and a nozzle that faces in the circumferential direction at a position away from the top of the hollow shaft to the side and is inclined downward with respect to the horizontal plane is connected. There is also a configuration in which the nozzle is rotated by the reaction force of the jet (see Patent Document 2).
[0004]
[Patent Document 1]
JP-A-59-131296 (pages 4 to 5, FIG. 2)
[Patent Document 2]
JP-A-54-153375 (pages 1-2, FIG. 1-3)
[0005]
[Problems to be solved by the invention]
However, in general, many of the stirring tanks for performing the stirring and mixing process have a rectangular shape. Even if the above-described conventional stirring device is installed in the center of the rectangular stirring tank, it is difficult to generate a strong swirling flow, and the stirring is difficult. Only weak effects are obtained.
In addition, these stirrers have only one nozzle in the vertical direction and are arranged near the water surface, so that the generated liquid flow is mainly convection in the vertical direction, for example, of turbid raw water and coagulant. A swirling flow around the vertical axis, which is suitable for mixing the liquid to be treated and the powder in a short time, hardly occurs.
[0006]
The present invention is to solve the above problems in the stirring device, it is possible to efficiently perform stirring and mixing by generating a strong swirling flow around the vertical axis and a turbulent flow in the vertical direction in the swirling cylinder, An object of the present invention is to provide a stirrer that generates convection in a vertical direction in a stirring tank and does not generate a stagnant portion of a liquid to be treated in the stirring tank.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the stirring device of the present invention is provided with a swirl cylinder having a large number of small holes in a peripheral wall in a stirring tank, a liquid supply pipe provided at the center of the swirl cylinder, and a swirl in the liquid supply pipe. A branch pipe extending in the radial direction of the cylinder is provided in multiple stages, a nozzle is provided in the branch pipe in a direction intersecting with the radial direction of the swirling cylinder, a liquid supply pipe is connected to a discharge port of the pump, and the liquid to be treated is contained in the swirling cylinder. And an inlet for introducing a flocculant.
[0008]
In operation, the stirring device supplies liquid to the nozzle from the pump via the liquid supply pipe and the branch pipe to eject the liquid. Since the nozzles are provided in multiple stages in a direction intersecting with the radial direction of the swirling cylinder, the liquid ejected from the nozzle hits the peripheral wall of the swirling cylinder and covers the entire area from the upper part to the lower part of the swirling cylinder. A strong swirling flow around the vertical axis is generated in the processing liquid. Accordingly, the liquid to be treated and the flocculant are efficiently stirred and mixed in the swirl cylinder.
[0009]
In addition, a part of the liquid to be processed flows out from the small hole in the peripheral wall of the swirling cylinder to the outside, and a water flow is generated also in the liquid to be processed between the peripheral wall of the rotating cylinder and the tank wall.
When the liquid supply pipe is extended above the liquid surface and a nozzle is provided from above to the liquid surface, the liquid ejected from the nozzle strongly impacts the liquid surface in the swirl cylinder from above, and the liquid in the swirl cylinder is damaged. This causes strong vertical turbulence in the processing liquid.
[0010]
In addition, when the swirling cylinder is arranged in the stirring tank at the upper end substantially equal to the liquid level and the lower end at a height that maintains a gap between the tank bottom and the nozzle at the tip of the branch pipe is inclined downward and provided, In addition to strengthening the turbulence of the liquid to be treated in the cylinder in the vertical direction, the liquid to be treated in the swirl cylinder moves downward, and the liquid to be treated outside the swirl cylinder generates upward convection, and the convection occurs in the stirring tank. It is possible to prevent stagnation of the liquid to be processed.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a front view of a wastewater treatment facility provided with a stirring device according to an embodiment of the present invention, FIG. 2 is a plan view of the wastewater treatment facility, FIG. 3 is a side view of the wastewater treatment facility, and FIG. FIG. 5 is a front view, FIG. 5 is a plan view of the turning tube, and FIG. 6 is a side view of the turning tube.
This wastewater treatment equipment 1 is for adding a coagulant to turbid raw water such as wastewater for construction work, stirring and mixing to coagulate and sediment the turbid substance, and separates it into clear treated water and sludge. A stirring device 3, a separation tank 4, and a water channel 5 that connects the stirring device 3 and the separation tank 4 are provided on a lower floor 2 </ b> A of the gantry 2.
[0012]
In addition, on the upper floor 2B of the gantry 2, a flocculant charging machine 6 is provided above the stirring device 3, and a flocculant storage box 7 is provided above the separation tank 4. A handrail 8 is provided around the upper floor 2B, and a ramp 9 for climbing to the upper floor 2B is attached to a side surface of the gantry 2.
In the stirring device 3, a revolving cylinder 11 having a number of small holes 11 </ b> B in a peripheral wall 11 </ b> A is provided in a stirring tank 12 in a vertical direction. The stirring tank 12 has a horizontal cross section in which four corners of a square are rounded in an arc shape, and the revolving cylinder 11 having a circular cross section is concentric with the center of the stirring tank 12, the upper end is substantially equal to the liquid level, and the lower end is the tank bottom 12A. It is arranged at a height that keeps a gap between
[0013]
A liquid supply pipe 13 is provided at the center of the revolving cylinder 11, and a branch pipe 14 extending in the radial direction of the revolving cylinder 11 is provided in multiple stages on the liquid supply pipe 13. A nozzle 15 is provided which is slightly downwardly inclined in a direction perpendicular to the radial direction. The lower end of the liquid supply pipe 14 is connected to a discharge port 17 of a pump 16 installed at the lower part of the stirring tank 12, and the upper end of the liquid supply pipe 14 extends above the liquid surface and is bent downward, and the distal end is bent from above. A nozzle 15 facing the liquid level is provided.
[0014]
A raw water inlet 20 for injecting raw water into the swirl cylinder 11 is provided at an upper portion of the stirring tank 12.
The flocculant charging machine 6 includes a cutout device 27 at the lower end of the hopper 26. The cutout device 27 has a coagulant inlet 28 into which the coagulant is injected into the swivel cylinder 11, and can inject the coagulant into the swivel cylinder 11.
[0015]
The stirring tank 12 has a tank bottom 12A inclined toward the front side, and a stirring tank discharge port 19 at the lower end. A raw water inlet 20 is provided in the upper part of the stirring tank 12. The stirring tank 12 is also provided with a surplus water discharge port 21.
The separation tank 4 has a rectangular horizontal cross section, and a plurality of partition walls 22 are provided alternately inside. As shown by the arrow in FIG. 2, the raw water to which the flocculant added from the stirring tank 12 through the water channel 5 coagulates and precipitates a turbid substance while passing through a zigzag flow path formed by the partition walls 22, and becomes clear. Separated into treated water and sludge, a treated water discharge port 23 for discharging clear treated water is provided at the end of this flow path.
[0016]
The tank bottom 4A of the separation tank 4 is inclined toward the front side, and a sludge discharge port 24 for discharging the settled sludge is provided at the lower end. The separation tank 4 is also provided with a surplus water discharge port 25.
When the wastewater treatment equipment 1 treats turbid raw water such as wastewater for construction work, the raw water is injected from the raw water inlet 20 into the swirl cylinder 11 of the stirring tank 12, and the coagulant is fed into the coagulant injection machine 6. And the pump 16 is operated. The pump 16 supplies the raw water sucked from the stirring tank 12 to the nozzle 15 via the liquid supply pipe 13 and the branch pipe 14, and causes the nozzle 15 to eject the raw water.
[0017]
Since the nozzles 15 are provided in multiple stages in a direction orthogonal to the radial direction of the swirl cylinder 11, the raw water spouted from the nozzle 15 hits the peripheral wall 11 </ b> A of the swirl cylinder 11 and covers the entire range from the upper part to the lower part of the swirl cylinder 11. A strong swirling flow around the vertical axis is generated in the raw water in the swirling cylinder 11. Thereby, the stirring and mixing of the raw water and the flocculant are efficiently performed in the swirl cylinder 11.
[0018]
The upper end of the liquid supply pipe 13 extends above the liquid surface, and since the nozzle 15 is provided from above to the liquid surface, the raw water is ejected from the nozzle 15 and the raw water strongly impacts the liquid surface in the swirl cylinder 11 from above. This causes strong vertical turbulence in the raw water in the swirl cylinder 11.
Part of the raw water flows out of the small holes 11B of the peripheral wall 11A of the swirling cylinder 11 to generate water flow also in the raw water outside the peripheral wall 11A of the rotating cylinder 11.
[0019]
In addition, the raw water in the swirl cylinder 11 moves downward, and the raw water outside the swirl cylinder 11 moves upward, so that a convection is generated, so that a place where the raw water stays in the stirring tank 12 is prevented.
The raw water to which the coagulant is added by the stirring device 3 and sufficiently mixed by stirring flows into the separation tank 4 through the water channel 5. The inflowing raw water passes through the zigzag flow path formed by the partition walls 22 and the turbid substances are coagulated and settled, and separated into clear treated water and sludge. The treated water is discharged from the treated water discharge port 23 to the outside of the system. Is done. The sludge in which the turbid substance has coagulated and settled is discharged from the sludge discharge port.
[0020]
Sludge settled in the stirring tank 12 is discharged from the stirring tank outlet 19.
When the raw water is excessive, the raw water is discharged from the surplus water discharge ports 21 and 25 to keep the liquid surface at a predetermined height and to perform a stable treatment.
In this stirring device 3, the nozzles 15 are provided in multiple stages in a direction orthogonal to the radial direction of the swirl tube 11, and the liquid ejected from the nozzles 15 hits the peripheral wall 11A of the swirl tube 11 and is entirely from the upper part to the lower part of the swirl tube. A strong swirling flow around the vertical axis is generated in the liquid in the swirling cylinder over the range. Further, since the liquid supply pipe 13 extends above the liquid surface and the nozzle 15 is provided from above to the liquid surface, the liquid ejected from the nozzle 15 strongly impacts the liquid surface in the swirl cylinder 11 from above. To cause strong vertical turbulence in the liquid in the swirl cylinder 11. Therefore, the stirring and mixing are efficiently performed in the swirl cylinder 11.
[0021]
Part of the liquid flows out of the small hole 11B of the peripheral wall 11A of the swirl cylinder 11 to the outside, and also generates a water flow in the liquid outside the peripheral wall 11A of the swirl cylinder 11. Further, the swirl cylinder 11 is disposed in the stirring tank 11 at a height such that the upper end is substantially equal to the liquid level and the lower end maintains a gap between the tank bottom 12A and the nozzle 15 at the tip of the branch pipe 14 is inclined downward. Therefore, in addition to strengthening the turbulent flow of the raw water in the swirl cylinder 11 in the vertical direction, the convection in which the raw water in the swirl cylinder 11 moves downward and the raw water outside the swirl cylinder moves upward, and the stirring tank It is possible to prevent the stagnation portion of the raw water from occurring in the inside 12.
[0022]
【The invention's effect】
As described above, the stirrer of the present invention can efficiently stir and mix by generating a strong swirling flow around the vertical axis and a turbulent flow in the vertical direction in the swirl cylinder, and can stir and mix efficiently in the stirring tank. A convection in the direction can be generated so that no liquid stagnation point occurs in the stirring tank.
[Brief description of the drawings]
FIG. 1 is a front view of a wastewater treatment facility provided with a stirring device according to an embodiment of the present invention.
FIG. 2 is a plan view of a wastewater treatment facility.
FIG. 3 is a side view of a wastewater treatment facility.
FIG. 4 is a front view of the turning cylinder.
FIG. 5 is a plan view of the turning cylinder.
FIG. 6 is a side view of the turning cylinder.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Drainage treatment equipment 2 Stand 3 Stirrer 4 Separation tank 5 Water path 6 Flocculant injection machine 11 Revolving cylinder 11A Peripheral wall 11B Small hole 12 Stirring tank 12A Tank bottom 13 Liquid supply pipe 14 Branch pipe 15 Nozzle 16 Pump 17 Discharge port 19 Stirring tank Outlet 20 Raw water inlet 22 Partition wall 23 Treated water outlet 24 Sludge outlet

Claims (3)

In the stirring tank, a swivel cylinder having a large number of small holes in the peripheral wall is provided vertically, a liquid supply pipe is provided at the center of the swirl pipe, and a branch pipe extending in the radial direction of the swirl pipe is provided in the liquid supply pipe in multiple stages, branching. A nozzle is provided in the pipe in a direction intersecting the radial direction of the swirling cylinder, a liquid supply pipe is connected to the discharge port of the pump, and an inlet for injecting the liquid to be treated into the swirling cylinder and an inlet for charging the coagulant. A stirring device. The stirring device according to claim 1, wherein the liquid supply pipe extends above the liquid surface and a nozzle is provided from above to the liquid surface. In the stirring tank, the swirl cylinder is disposed at a height such that the upper end is substantially equal to the liquid level and the lower end maintains a gap between the tank bottom and the nozzle of the branch pipe is inclined downward. Item 3. The stirring device according to item 1 or 2.

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