JP3688828B2 - Pumping device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pumping device, and more particularly, a pumping device for pumping a liquid in which a floating substance exists in the liquid while separating the floating substance, for example, a nitrification tank carrier input type activated sludge circulation TECHNICAL FIELD The present invention relates to a pumping device suitable for use as a nitrifying solution circulation in a wastewater treatment device by the method.
[0002]
[Prior art]
Conventionally, a circulating nitrification denitrification method including a denitrification tank and a nitrification tank has been widely adopted as a method for removing nitrogen content in waste water. This circulatory nitrification denitrification method basically consists of a denitrification tank under anaerobic conditions in the first stage and a nitrification tank under aerobic conditions in the first stage, and nitrate nitrogen and nitrite nitrogen produced in the nitrification tank are used. This is a treatment method in which the nitrifying liquid contained is returned to the preceding denitrification tank and brought into contact with raw water, and denitrification is performed by the action of denitrifying bacteria (anaerobic bacteria) using BOD in the raw water.
[0003]
Conventionally, as a means for returning the nitrification solution from the nitrification tank to the denitrification tank, a general pump such as a centrifugal pump has been used. However, in the circulation type nitrification denitrification method, the nitrification tank is usually returned from the nitrification tank to the denitrification tank. The amount of nitrating liquid to be flowed is set to 1 to 3 times the raw water, and to about 6 times when it is large, so the flow rate of nitrating liquid is extremely large, the energy consumption of the pump is enormous, and the running cost is greatly affected. Was. In addition, since the nitrification tank and the denitrification tank are usually provided at the same level, the performance of the pump itself (lift head, etc.) is excessive, which contributes to an increase in cost.
[0004]
For this reason, the nitrification liquid is also returned from the nitrification tank to the denitrification tank by utilizing the air lift effect of the entire aeration air in the nitrification tank. In other words, by adding air bubbles generated from the diffuser to make the inside of the nitrification tank aerobic, the apparent specific gravity of the treated water is reduced and the water level is adjusted by an amount corresponding to the specific gravity difference. In addition to raising the water level, the water level in the nitrification tank is made higher than the water level in the denitrification tank using the rise in liquid level accompanying the rise of air bubbles so that the treated water (nitrification liquid) flows down to the denitrification tank. Yes.
[0005]
[Problems to be solved by the invention]
However, the air bubbles supplied to the nitrification tank are for making the inside of the nitrification tank aerobic, and the pumping by the air lift effect is secondary. If the inflow or outflow changes, it may not be possible to secure a predetermined return flow rate, and there is also a problem that it is difficult to adjust the return flow rate because the pumped amount is affected by the water level. .
[0006]
Furthermore, in any return means, when a nitrifying bacteria-immobilized carrier is introduced into the nitrification tank, a solid-liquid separation device such as a fixed screen is installed to prevent the carrier from being entrained in the return water. However, there is a possibility of clogging due to tangling of the residue remaining in the inflowing water or the carrier clogged in the screen or the like.
[0007]
Therefore, the present invention is suitable for use as a nitrification liquid circulation in a wastewater treatment apparatus using such a nitrification tank carrier input type activated sludge circulation method, can easily control the amount of pumped liquid, and reliably separate solids such as a carrier. An object of the present invention is to provide a liquid pumping apparatus that can be used for the above.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a liquid pumping apparatus according to the present invention includes an endless screen panel installed from the liquid to the liquid surface, a drive source for rotationally driving the screen panel, and both sides of the inner peripheral portion of the screen panel. A closing plate that closes at least the liquid portion, a pumping bucket provided on the inner peripheral side of the screen panel, and a liquid receiver provided above the liquid level on the inner peripheral portion on the rising side of the pumping bucket. The liquid bucket has an outlet on the liquid receiver side, and the liquid receiver has a pumping plate for closing the outlet of the liquid bucket that rises upward from the liquid toward the liquid receiver. It is characterized by that. Further, a nozzle for ejecting a pressure fluid from the inside to the outside of the screen panel is provided.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to the drawings. 1 is a schematic side view showing an example of the liquid pumping apparatus of the present invention, FIG. 2 is a front view of the liquid pumping apparatus, FIG. 3 is a cross-sectional view, FIG. 4 is a perspective view of the main part, and FIG. It is a schematic plan view which shows the example of installation to the waste water treatment equipment by a denitrification method.
[0010]
The pumping device includes an endless screen panel 1 installed from the liquid to the liquid surface, a pumping bucket 2 provided on the inner peripheral side of the screen panel 1, and a rising side of the pumping bucket 2. It has a liquid receiver 3 provided above the liquid surface of the inner peripheral part and a nozzle 4 for ejecting a pressure fluid from the inside to the outside of the screen panel 1. The motor 7 is supported by the endless chain 5 and is rotatably supported by a guide and a sprocket (not shown) provided on a closing plate 6 that closes both sides of the inner peripheral portion of the screen panel 1. It is driven by rotation.
[0011]
The pumping bucket 2 is a box-like shape in which an opening serving as an outlet 2a is formed on one side of the liquid receiver 3, and the liquid receiver 3 is a pumped liquid that rises from the liquid toward the upper part of the liquid receiver. A liquid lifting plate 3a for closing the outlet 2a of the bucket 2 is provided in the vertical direction.
[0012]
When the pumping device formed in this way is rotated in the direction of the arrow shown in FIG. 1, water in the pumping bucket 2 that rises from the liquid on the left side of FIG. Since it is closed by the liquid plate 3a, the amount of the portion surrounded by the pumping bucket 2 and the pumping plate 3a is pumped up, and the liquid receiver 3 is moved by moving the pumping bucket 2 upward from the pumping plate 3a. Then, the liquid flows down and is sent to a desired facility through an appropriate flow path connected to the liquid receiver 3.
[0013]
Further, since the water or the like to be pumped is closed on both sides by the closing plate 6, it passes through the screen panel 1 and flows into the inner peripheral portion of the screen panel 1, so that floating substances in the liquid may enter. In addition, only the water or the like can be pumped by the pumping bucket 2. At this time, the suspended matter captured by the screen panel 1 is removed from the screen panel 1 by pressure fluid such as the inclination of the screen panel 1 and water ejected from the nozzle 4 and returned to the liquid again.
[0014]
Since the pumping device can determine the pumping amount based on the volume of the pumping bucket 2, the number of the pumping buckets 2 installed, and the rotation speed thereof, it is easy to change the flow rate during operation by adjusting the rotation speed. Can be controlled.
[0015]
The pumping device formed in this way is suitable for, for example, installing in the nitrification tank 11 of the wastewater treatment device by the circulating nitrification denitrification method shown in FIG. 5 to return and discharge the nitrification solution. This waste water treatment apparatus has a denitrification tank 12 into which raw water and nitrification liquid flow and a nitrification tank 11 into which treated water from the denitrification tank 12 flows. 11 is connected to a nitrification liquid return flow path 13 for returning the treated water in the denitrification tank 12 and a treated water delivery flow path 14 for delivering the treated water to the next treatment step.
[0016]
The raw water flowing into the denitrification tank 12 from the raw water inflow section 15 is mixed with 1 to 6 times the amount of circulating nitrification liquid flowing in from the nitrification liquid return flow path 13 and dehydrated under anoxic conditions while being stirred by a stirrer. After being subjected to nitriding treatment, it flows into the nitrification tank 11 from the flow path 16 and is nitrified by the nitrifying bacteria carried on the nitrifying bacteria immobilization support in an aerobic state while being agitated by the air supplied from the air diffuser. .
[0017]
Then, the treated water in the nitrification tank 11 is pumped to the liquid receiver 3 by the pumping device A, and then a predetermined amount branches and flows into the nitrifying liquid return flow path 13 and the treated water delivery flow path 14, A part is sent from the treated water delivery channel 14 to the next process, and 1 to 6 times the amount is sent back to the denitrification tank 12.
[0018]
Thus, by using the pumping apparatus A having the above-described configuration, the nitrification liquid can be returned to the denitrification tank 12 at a stable flow rate compared with the return flow of the nitrification liquid using the air lift effect, and the circulation rate is increased. Thus, the denitrification efficiency can be improved, and the cost can be reduced as compared with a general pump.
[0019]
Furthermore, a nozzle 4 is provided on the inner peripheral side of the screen panel 1, and water, air, or the like is ejected from the nozzle 4 toward the outside of the screen panel 1, thereby further removing the carrier, residue, etc. attached to the screen panel 1. Since it can be reliably removed from the screen panel 1, it is possible to prevent the carrier from flowing out, to prevent the screen panel 1 from being blocked, and to reduce the screen area.
[0020]
The shape of the screen panel and the liquid bucket is not limited to the above embodiment, and for example, the screen panel and the liquid bucket can be integrally formed, and the whole can be rotated into a circular shape. it can. Further, the screen panel is preferably formed in a mountain shape as shown in the drawing, from the viewpoint of removal of trapped substances from the screen panel, but can also be formed in a flat shape. Furthermore, the use of the pumping device is not limited to the waste water treatment device, and can be used as a pumping means for various facilities and devices.
[0021]
【The invention's effect】
As described above, according to the liquid pumping apparatus of the present invention, liquid can be pumped in a stable state while separating suspended matters in the liquid, and the amount of liquid pumping can be easily adjusted. In particular, since floating substances adhering to the screen can be easily removed, the screen is not blocked during operation, and the screen area can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic side view showing an example of a liquid pumping apparatus according to the present invention.
FIG. 2 is a front view of a pumping device.
FIG. 3 is a cross-sectional view of the same.
FIG. 4 is a perspective view of a main part.
FIG. 5 is a schematic plan view showing an installation example of a liquid pumping apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Screen panel, 2 ... Pumping liquid bucket, 2a ... Outlet, 3 ... Liquid receptacle, 3a ... Pumping plate, 4 ... Nozzle, 5 ... Endless chain, 6 ... Closing plate, 7 ... Electric motor

Claims (2)

An endless screen panel installed from the liquid surface to the liquid surface, a drive source for rotationally driving the screen panel, a blocking plate for closing at least the liquid portion on both sides of the inner periphery of the screen panel, A pumping liquid provided on the inner peripheral side, and a liquid receiver provided above the liquid surface of the inner peripheral part on the rising side of the pumping bucket, the pumping bucket being an outlet on the liquid receiving side The liquid receiver includes a pumping plate that closes an outlet of the pumping bucket that rises from the liquid toward the upper side of the liquid receiver. 2. The liquid pumping apparatus according to claim 1, wherein a nozzle for ejecting a pressure fluid toward the outside of the screen panel is provided inside the screen panel.

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