JP6436008B2 - Propeller underwater agitator and propeller underwater agitator with swivel mechanism - Google Patents

Description

  The present invention relates to a propeller-type underwater agitator used for the treatment of sewage and industrial wastewater.

In a treatment tank for performing sewage treatment using a biological reaction, a stirrer may be installed in order to prevent sedimentation of sludge in the treatment tank and improve treatment efficiency (Patent Documents 1 and 2). reference).
In Patent Document 1, as shown in FIG. 7, a processing tank 1 is described in which a propeller type underwater agitator 2 of an outside-drive type is installed in the main body of the processing tank 1 and a reflecting plate 3 is installed therebelow. . In the treatment tank 1, the downward flow 4 discharged by the propeller-type underwater agitator 2 is converted into a horizontal flow by the reflecting plate 3, and this horizontal flow prevents accumulation of sludge at the bottom of the treatment tank.

  Further, in Patent Document 2, in a treatment tank equipped with a fixed type propeller type stirrer, a large capacity stirrer is used in order to secure a flow rate necessary for preventing sludge deposition over the entire bottom surface of the tank. In view of the problem that it is necessary to arrange a stirrer, as shown in FIG. 8, a propeller type underwater agitation is provided that has a stirring propeller blade and has a swinging function with a substantially vertical axis as a swing rotation axis. A treatment tank 1 in which a machine 2 is installed is described.

  By using the stirrer 2 having such a swing function, as shown in FIG. 8 (b), when the inflowing water 15 flowing in from the inflowing water inlet 14 flows into the treatment tank 1 due to gravity fall, A flow 16 is generated in the processing tank, and a flow from left to right is formed toward the paper surface of FIG. 8B at the bottom of the processing tank 1. In this case, the direction of the acceleration flow by the stirring propeller blades of the stirrer 2 is set in the direction in which the flow is strengthened so that the energy of the flow at the bottom of the treatment tank 1 can be used for the acceleration flow by the stirrer 2. This makes it possible to more effectively accelerate the flow velocity at the bottom of the treatment tank using the energy of the flow created by the inflowing water, and the reach distance of the accelerated flow is increased. As a result, the stirring propeller of the stirrer 2 is increased. The accelerating flow by the blades reaches every corner of the treatment tank, and the activated sludge that is about to deposit at the bottom of the treatment tank is effectively rolled up into the water, and sludge accumulation can be effectively prevented.

JP 2008-284421 A JP 2002-316185 A

In a conventional propeller-type stirrer, it is necessary to use a large-capacity stirrer or to arrange a plurality of stirrers in order to obtain a bottom flow rate necessary for mixing and stirring sewage and sludge.
Therefore, an object of the present invention is to provide a propeller-type underwater stirrer that is energy-saving and that can directly apply a stirring force to the entire area of the treatment tank, and is lightweight and easy to maintain.

  As a result of studying the above problems, the present inventor has provided a cylindrical water flow guide so as to cover the propeller, and provided a cylindrical rectifying guide downstream of the water flow guide. The present invention has been completed by finding that the above-mentioned problems can be solved by using.

The present invention is a propeller-type underwater agitator as described below.
(1) A propeller-type underwater stirrer equipped with a propeller for stirring,
A cylindrical water flow guide that surrounds the propeller portion, and a cylindrical flow straightening guide that is connected to the downstream opening edge of the water flow guide,
A plurality of plate-like blades having a length shorter than the radius of the rectifying guide are provided on the inner peripheral surface of the rectifying guide, spaced in the circumferential direction in parallel or at an angle with respect to the water flow. A propeller for agitating sewage in a sewage treatment tank, wherein the propeller is attached toward the radial center of the guide, and a hollow part without the blades is formed in the central part of the rectifying guide. Formula underwater stirrer.
(2) The upstream edge of the blade is notched or arcuate so that the width of the blade decreases toward the radial center of the rectifying guide. The propeller-type underwater agitator according to (1).
(3) The propeller-type underwater agitator according to (1) or (2) above, wherein the upstream portion of the water flow guide has a tapered shape whose diameter decreases from the upstream side toward the downstream side. .
(4) The propeller-type underwater agitator with a swiveling mechanism characterized in that the propeller-type underwater agitator according to any one of (1) to (3) is attached to a swivel shaft so that the propeller-type underwater agitator can be turned. Machine.

  The propeller-type underwater stirrer of the present invention is energy-saving, lightweight and easy to maintain and manage, and can be used for mixing and stirring in the treatment tank to obtain a sufficient bottom flow velocity, providing direct stirring power over the entire area of the reaction tank. Can be given.

It is a figure which shows schematic structure of the propeller-type underwater stirrer of this invention. It is a figure which shows the structure of the water flow guide and rectification | straightening guide in the propeller-type underwater stirrer of this invention. It is a figure which shows the attachment structure of the blade | wing in the rectification | straightening guide of this invention. It is a figure which shows the detail of the structure of the blade | wing of a rectification | straightening guide. It is a figure which shows the state which attached the propeller type underwater stirrer of this invention to the turning apparatus. It is a figure which shows the sewage treatment apparatus to which the propeller-type underwater stirrer of this invention is applied. It is a figure which shows the state which installed the propeller type submerged stirrer with a turning mechanism in a processing tank. It is a figure which shows the processing tank which installed the conventional propeller-type underwater stirrer. It is a figure which shows the processing tank which installed the conventional propeller type underwater stirrer with a turning mechanism.

An embodiment of the propeller type underwater agitator of the present invention will be described in detail with reference to FIGS.
The propeller-type underwater stirrer 40 of the present embodiment includes a stirrer body 1 provided with a propeller 11 shown in FIG. 1 (a), a water flow guide 2 shown in FIG. 1 (b), and a rectification shown in FIG. 1 (c). It is formed by assembling the guide 3 as shown in FIG.

FIGS. 2-1 (a) and 2-1 (b) are perspective views of the water flow guide 2 and the rectifying guide 3, respectively.
The water flow guide 2 has a cylindrical shape and is arranged so as to cover the outer peripheral portion of the propeller 11 of the agitator body 1. The straightening guide 3 is a cylindrical member having substantially the same diameter as the water flow guide 2, and is connected to the downstream opening edge of the water flow guide 2.
It is preferable that the upstream portion of the tubular portion of the water flow guide has a taper shape whose diameter is reduced from the upstream side toward the downstream side.
In FIGS. 1 and 2-1, the cylindrical walls of the water flow guide 2 and the rectifying guide 3 are shown transparent so that the internal structure of the propeller-type underwater stirrer 40 can be easily understood.

The attachment structure of the blades 31 in the rectifying guide 3 is shown in FIG.
The upper figure of FIGS. 2-2 (a) and 2-2 (b) is a front view of the rectifying guide 3, and the lower figure is a side view of the rectifying guide 3 seen from the direction of the arrow in the figure.
In the case shown in FIG. 2-2 (a), the radial direction of the rectifying guide 3 is spaced from the inner peripheral surface of the rectifying guide 3 so that a plurality of plate-like blades 31 are parallel to the water flow. It stands up to the center of Moreover, in what was shown to FIG. 2-2 (b), the space | interval of the rectification guide 3 is spaced apart so that the several plate-shaped blade | wing 31 may have an angle with respect to a water flow in the internal peripheral surface of the rectification guide 3. It is erected so as to go to the center in the radial direction.

The blade 31 is reinforced by being fixed at the rectifying guide 3 by sandwiching the base portion of the blade 31 from both front and back sides by two reinforcing plates 32. By providing the blades 31, the straightness of the water flow generated from the propeller 11 is improved, and the reach of the water flow is increased. Further, the longer the axial length of the rectifying guide 3 of the blade 31 is, the more the rectifying effect is improved.
Hereinafter, the axial length of the flow straightening guide 3 of the blade 31 is referred to as a blade width D, and the length perpendicular to the axial direction of the flow straightening guide 3 is referred to as a blade length L.

FIG. 3 shows details of the structure of the blade 31 of the rectifying guide 3.
FIG. 3A is a view showing a cross section of the propeller-type underwater stirrer 40, and FIGS. 3B and 3C are enlarged views of a portion X in FIG. 3A.
As shown in FIGS. 3 (b) and 3 (c), the upstream side edges 35, 35 ′ of the blade 31 are notched so that the blade width D decreases toward the radial center of the rectifying guide 3. 3 (b)) or arcuate (see FIG. 3 (c)).
The cutout portion 35 and the arcuate portion 35 ′ may be provided over the entire length of the upstream end edge of the blade 31, but may be provided only in a portion on the center side of the rectifying guide 3.

  Further, the length L of the blade 31 is made shorter than the radius of the rectifying guide 3 to form a space (hollow portion) 34 without the blade 31 in the central portion of the rectifying guide 3. By adopting such a configuration, as shown in FIG. 3B, the residue 36 such as fibrous dust entangled with the blade 31 is formed on the edges 35, 35 ′ of the blade 31 as indicated by an arrow F. It moves toward the center along the slope and is discharged through the cavity 34.

  If the number of blades 31 is too large, resistance to water flow increases, and if it is too small, the rectifying effect decreases. From the above viewpoint, the number of blades 31 is preferably 6 to 8.

The propeller-type underwater stirrer of the present invention may be attached to a swivel shaft having a substantially vertical swivel shaft and used as a stirrer having a swing function.
FIG. 4 is a view showing a state in which the propeller-type underwater agitator 40 of the present invention is attached to the turning device 50. The propeller-type submerged stirrer 40 is attached to a swivel column 51 that is a swivel shaft that is swiveled by a swivel driving device 52, and the propeller-type submerged stirrer 40 swings as the swivel column 51 turns. The propeller-type underwater agitator 40 is inspected by sliding the swivel strut 51 to the inspection position 53 during inspection.
As the propeller-type underwater agitator 40 stirs the sewage in the treatment tank while swinging in this manner, the acceleration flow by the propeller 11 extends intermittently to the entire bottom of the treatment tank. The prevention effect can be improved.

An example of a sewage treatment apparatus to which the propeller-type underwater stirrer of the present invention can be applied will be described.
FIG. 5 is a view showing a sewage treatment apparatus 60 for removing phosphorus and nitrogen by an anaerobic-anoxic-aerobic method.
The raw water W1 first precipitates small sand and dust floating in the sewage in the settling basin 61, and then the solid matter is captured by a screen by the automatic dust remover 62 and scraped off.
The water to be treated discharged from the automatic dust remover 62 is dephosphorized by being stirred by the stirrer 40a without sending air in the anaerobic tank 63.

  The dephosphorized water to be treated flows into the anaerobic tank 64 and is mixed with the nitrification liquid 71 returned from the aerobic tank 65 in the subsequent stage without being fed with air. Nitric acid is converted to nitrogen and released into the atmosphere.

The water to be treated discharged from the anaerobic tank 64 flows into the aerobic tank 65, and the air sent from the blower 652 is supplied into the water to be treated by the air diffuser 651. In the aerobic tank 65, phosphorus is taken into microorganisms, organic substances are decomposed, and ammonium ions are converted into nitrate ions.
Next, the water to be treated flows out of the aerobic tank 65 after the carrier is separated by the carrier separation device 653 when the microorganism is supported on the carrier.

A part of the water to be treated that has flowed out of the aerobic tank 65 is returned to the anoxic tank 64 as the nitrification liquid 71, and the remaining part flows into the final sedimentation tank 67.
The sludge that has settled in the final sedimentation basin 67 is extracted by the sludge pump 66, a part is returned to the anaerobic tank 63 as the return sludge 72, and the remainder is discharged out of the system as the excess sludge 73.
The propeller-type underwater stirrer of the present invention can be suitably used as the stirrer 40a in the anaerobic tank 63 and the stirrer 40b in the anaerobic tank 64.

  The present invention will be described below in more detail based on examples, but the technical scope of the present invention is not limited to the following examples.

※流速は、１旋回（1840秒）中に観測された瞬間最大値及び瞬間最小値を示す。
最大値は通常、プロペラが測定点に真っ直ぐ対向したときに観測される。 Example 1
In order to confirm the effect of the rectifying guide in the propeller-type underwater agitator of the present invention, the following test was performed.
<Test method>
-The processing tank of 360 degree rotation type (1 rotation cycle = 1840 seconds) installation was used.
・ As shown in Fig. 6, a flowmeter was fixed at a position 100 mm from the bottom of the tank opening (11.7 m from the stirrer) farthest from the stirrer, and the time-dependent change in the bottom flow rate in one cycle of operation was measured. did.
・ The driving power was the same regardless of whether the rectifying guide was used or not.
<Test results>
The test results are shown in Table 1 below.

* The flow velocity indicates the instantaneous maximum value and instantaneous minimum value observed during one turn (1840 seconds).
The maximum value is usually observed when the propeller is directly opposite the measurement point.

As described above, the flow velocity was improved by 18% by attaching the flow straightening guide.
Since the flow velocity is improved, the following advantages can be obtained.
-There is a possibility that one unit can handle a treatment tank that could not be handled by one unit.
・ Because there is room in the flow velocity, there is a possibility that it can be operated with lower operating power, and an energy saving effect can be expected.

(About FIGS. 1-6)
DESCRIPTION OF SYMBOLS 1 Stirring machine main body 2 Water flow guide 3 Flow guide 11 Propeller 12 Fixing tool 21 Fixing tool 31 Blade 32 Reinforcement plate 33 Fixing tool 34 Cavity 35, 35 'Upstream side edge 36 Residue 40 Propeller type underwater stirring machine 50 Turning apparatus 51 Swivel column (rotating shaft)
52 Swivel drive device 53 Inspection position 60 Sewage treatment device 61 First sedimentation tank 62 Automatic dust removal machine 63 Anaerobic tank 64 Anoxic tank 65 Aerobic tank 651 Aeration apparatus 652 Blower 653 Carrier separation apparatus 66 Return sludge pump 67 Final sedimentation tank 71 Nitrification liquid 72 Return sludge 73 Excess sludge D Blade width L Blade length F Slag movement W, W1 Raw water W2 Treated water (about FIGS. 7 and 8)
DESCRIPTION OF SYMBOLS 1 Treatment tank 2 Propeller type underwater agitator 3 Reflector 4 Down flow 14 Inflow water inlet 15 Inflow water 16 Swirling flow

Claims (4)

A propeller-type underwater agitator equipped with a propeller for stirring,
A cylindrical water flow guide that surrounds the propeller portion, and a cylindrical flow straightening guide that is connected to the downstream opening edge of the water flow guide,
A plurality of plate-like blades having a length shorter than the radius of the rectifying guide are provided on the inner peripheral surface of the rectifying guide, spaced in the circumferential direction in parallel or at an angle with respect to the water flow. Agitating the sewage in the sewage treatment tank, wherein the rectification guide is attached toward the center in the radial direction, and a hollow portion without the blades is formed in the center of the rectifying guide . Propeller type underwater agitator.   The upstream edge of the blade is notched or arcuate so that the width of the blade decreases toward the radial center of the rectifying guide. The propeller-type underwater agitator as described.   The propeller-type underwater agitator according to claim 1 or 2, wherein an upstream portion of the water flow guide has a taper shape whose diameter decreases from the upstream side toward the downstream side.   A propeller-type underwater agitator with a turning mechanism, wherein the propeller-type underwater agitator according to any one of claims 1 to 3 is attached to a turning shaft so that the propeller-type underwater agitator can be turned.

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