JPH02174998A - Mixing aerator for aeration tank - Google Patents

Abstract

PURPOSE:To stably, efficiently and uniformly aerate sewage by mounting screw type aerators adjustably in horizontal mounting angle so as to maintain the flow velocity on the inner peripheral side of the water path higher than on the outer peripheral side according to the shape and size of the endless water path. CONSTITUTION:The screw type aerator 2 is so constituted as to generate water flow by the rotation of a screw 2 and to suck the air through a hollow shaft 23 by utilizing the negative pressure at the front end of the screw 26 arising from the water flow, thereby supplying the air in the form of fine air into the sewage and to efficiently penetrate the bubbles in the water. The aerator 2 is mounted in the water path 13 by fixing a motor 22 to a mounting frame 21. The horizontal mounting angle of the aerator 2 is made adjustable and the angle thereof in the direction tangent to double circular aeration tanks 1 is made adjustable by means of a mounting angle adjuster 25. The flow velocity on the inner peripheral side of the circulating water path 13 is made higher than on the outer peripheral side by installing such aerators in such a manner that the horizontal mounting angle is directed inward and by operating the aerators.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for uniformly mixing wastewater and performing efficient and uniform aeration in an aeration tank having an endless waterway.

[Conventional technology]

When treating sewage containing organic matter such as sewage sewage and industrial waste sewage, an aeration machine is installed in an aeration tank that has an oval circulation waterway or a double circular waterway with no markings or end channels. A method has been proposed in which wastewater is mixed and stirred while continuously supplying air, that is, oxygen in the air, to carry out an aerobic fermentation treatment.

[To be solved by the invention [1118] In a double circular aeration tank having an endless nursery channel, two aerators are installed parallel to each other in a direction perpendicular to a straight line passing through the center of the tank, Then, at a position a little more than 1.80 degrees turned from the 1ft aerator B position, flowmeters were placed at required intervals from the inner circumference to the outer circumference of the waterway, and while the aerator was running, it was inside the waterway. The flow velocity at each point was measured.

As shown in FIG. 2 (1), it was found that the flow velocity at each measurement point in FIG. 1 a, l) t C1d was slow at the inner circumference of the waterway, and faster toward the outer circumference.

In this way, the uneven flow velocity in the waterway makes it impossible to achieve good aeration no matter how much aeration is performed, and a swirl phenomenon occurs, causing sludge to accumulate on the inner circumference of the waterway, and this accumulated sludge rots.
New problems arise that degrade water quality.

In view of this, the present invention installs an aerator so that the flow velocity inside the waterway by the aerator is increased compared to the outer circumferential side according to the shape and size of the endless waterway to be aerated, and the aerator is installed throughout the waterway. Uniform flow rate allows for uniform mixing with less power,
Efficient lE that prevents sludge accumulation and water aggravation! The purpose is to practice qi.

[Means to solve the problem]

Shape of 21% end waterway to be aerated 9 Install the screw type aerator so that the horizontal mounting angle can be adjusted so that the flow velocity on the inner circumferential side of the waterway by the aerator is increased compared to the outer circumferential side according to the size. Equalize the flow velocity throughout the waterway and mix the waterway uniformly.

[For production]

An aerator installed in an endless waterway is installed around the inner circumference of the water (1!
l Change the horizontal installation angle of the screw type aerator with respect to the waterway of the tank so that the flow rate is increased more than its outer circumference! 2g
By doing so, the wastewater in the waterway is mixed uniformly, and the swirl phenomenon is prevented. This also solves the problems of sludge accumulation and water quality deterioration.

〔Example〕

The homogeneous mixing aeration device in the 16-air tank of the present invention will be explained below based on the illustrated embodiment.

The one in FIG. 1 is an embodiment using a double circular aeration tank with a circular endless water channel.

1 is a double circular aeration tank, which has a small diameter circumferential wall 11 and a large diameter outer circumferential wall 12 arranged concentrically.

A circulation waterway unit 23 having a required width and depth is formed on both the inner and outer circumferential walls 11, 121!8.

2 is a screw type aerator, which, as shown in Figure 5, consists of a hollow shaft directly connected to a motor and a screw.The rotation of the screw generates a water flow, and the resulting negative pressure at the tip of the screw is reduced. Air is sucked in through a hollow shaft and supplied into the wastewater as fine bubbles, so that the bubbles are efficiently dissolved into the water.

In the aerator 2, a motor 22 is fixed to a mounting frame 21, a hollow shaft 23 is directly connected to the motor 22, the motor and the hollow shaft are covered with a cover 24, and the motor etc. are attached to the frame through this cover. In this case, the horizontal mounting angle of the aerator relative to the waterway can be arbitrarily adjusted via a mounting angle adjuster 25, and a screw 26 of a desired shape is provided at the tip of the hollow shaft.

Then, the horizontal installation angle of each aerator 2 with respect to the tank, that is, the angle in the tangential direction to the double circular aeration if 1, can be adjusted respectively 1. For example, the horizontal installation angle of the inner aerator is α, Horizontal installation angle β
and (1) α=0° β=O.

(2) α = 9″, β = 6° (3) α = 9
It was operated using two free-air machines at each mounting angle: °, βa did not change (4) αR did not change, β = i39 (5) β = 45''.

Current velocity meters a and b are placed at a position 180 degrees or more from the set position of the aerator 2 and at a height of 10 (1) from the bottom to measure the flow velocity in the water g13 in each operating state.

c and d were installed and measured, and the results are shown in Figure 2.

From now on, α29″, β=6° and α=
9°, β When the operation is not performed, the flow velocity on the inner circumferential side and the outer circumferential side of the water channel] 3 is almost equalized. This is because the flow velocity on the inner circumferential side of the circulation waterway 13 increases compared to the flow velocity on the outer circumferential side J by operating the aerator 2 with its horizontal mounting angle facing inward.

Moreover, what is shown in FIG. 3 shows eleven oval air tanks 3. In this embodiment, two aeration devices 2 are installed in a straight line position of the circulation waterway 33. In this straight + path, the center line of the aeration device installed on the inside of the long 1-wheel center is directed slightly inward to increase the inner periphery 0tll flow velocity. The aeration devices installed on the outside are installed with their center lines facing slightly outward to increase the flow velocity near the inner and outer peripheral walls compared to the center. In this way, the flow velocity on the water flow surface can be made uniform not only in the straight section but also in the swirling section.

Furthermore, Fig. 4 shows a different embodiment in which the aeration device J9 placement method was changed in a double circular aeration tank, but (A) shows a different example in which the aeration device J9 was placed closer to the inner circumference than the center of the flow path. This is an example, (B) is an example where the water flow direction is directed inward, and (C)
1 and 2 show examples in which an aeration device having a larger capacity than an outside aeration device is arranged inside to increase the flow velocity on the inner peripheral side.

〔Effect of the invention〕

In accordance with the shape and size of the endless waterway to be aerated, the present invention is designed so that the horizontal installation angle of the aerator is directed inward so that the flow velocity inside the waterway due to the paper machine is increased compared to the periphery side. This allows the flow velocity to be uniform throughout the waterway, ensuring uniform mixing throughout the waterway, preventing swirl phenomena, and allowing wastewater to be mixed uniformly across the width of the waterway, ensuring stable and efficient flow of wastewater. Targeted and uniform aeration can be performed.
Moreover, the screw type aerator allows air to be self-suctioned, which has the advantage of simplifying the equipment.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention @low-weight ζ homogeneous mixing @'A device. Figure 1 is a plan view of a double circular aeration tank, and Figure 2 is a plan view of a double circular aeration tank.
The figure is a graph showing flow velocity values at each point in the waterway, Figure 3 is a 111-view diagram of an oblong aeration tank, Figure 4 is an explanatory diagram of different embodiments, and the fifth factor is an explanatory diagram of an aerator. . 1 is a double circular aeration tank, 2 is @ paper machine, and 3 is oval @ iA monk.

Claims (2)

[Claims] (1) The horizontal mounting angle of the screw type aerator can be adjusted and installed so that the flow velocity of the aerator on the inner circumferential side of the waterway is increased compared to the outer circumferential side according to the shape and size of the endless waterway to be aerated. A mixed aeration device in an aeration tank characterized by: (2) Mixed aeration in the aeration tank according to item 1, wherein the horizontal mounting angle of the screw type aerator has a predetermined angle from the tangential direction of the waterway curve at the mounting position to the inner circumferential side of the waterway. Device.