JPS60206492A - Aeration tank - Google Patents

Abstract

PURPOSE:To prevent the accumulation of sludge by enhancing recirculation efficiency, by providing a suction port in a state contacted with a tank bottom or in close vicinity thereto and fixing an earator equipped with a water scattering amount control apparatus to the tank. CONSTITUTION:An aerator 1 is fixed to an aeration tank to prevent sludge from sticking to the tank bottom 101 in sucking the same. The suction port 5 of the aerator 1 is arranged in close vicinity to the tank bottom 101 so as to suck up sludge on the tank bottom 101. A valve 2 for controlling a water scattering amount is mounted to the discharge port of the aerator 1 and a nozzle 4 is formed to said discharge port so as to be capable of remotely scattering sludge. Treated sewage is sucked up from the suction port 5 provided in close vicinity to the tank bottom by the impeller 3 rotated by the motor M provided to the upper part of the aerator 1 and scattered toward the liquid surface of the tank through the nozzle 4.

Description

[Detailed description of the invention] (Subject of invention, field of industrial application) The present invention relates to an aeration tank.

The invention is used in the field of activated sludge treatment.

(Prior art and its problems) Conventional aeration equipment for aeration tanks can be roughly divided into five types.
There is a blower type (bubble type) shown in the figure and a float type surface stirring type shown in FIG. Each of these methods had its own problems.

Blower-type aeration tanks require a machine room to install near compressors, etc., so the installation space is large.

(b) If the water depth of the aeration tank is deep, water pressure will cause the aeration pipe 21 to
A large amount of power is required for the near compressor to prevent the small holes provided in the compressor from clogging.

(c) Oxygen supply efficiency is relatively low compared to the surface stirring type.

(d) In order to increase the oxygen supply efficiency, there are methods such as making the bubbles smaller, but this requires a new device to make the bubbles finer and also has drawbacks such as clogging of the air diffuser pipe 21 (e ) With a typical blower volume, there is some circulation in the tank, but sludge tends to accumulate on the bottom of the tank.

Note that 20 is an air pipe, 21 is an aeration device, 0 is treated sewage, D is a sludge deposit, and 100 is a tank.

In a surface stirring aeration tank, (a) The amount of oxygen supplied is generally controlled by intermittent operation using a timer, but with this method, it is difficult to control the amount of dissolved oxygen and to automate it.

(b) Since the sludge settles during the suspension of operation during intermittent operation, the stirring efficiency is poor when the operation is restarted.

(c) Due to the structure of the surface stirring type, there is a part (dead space) at the bottom of the tank that is difficult to stir, so sludge tends to accumulate.

(d) In order to reduce the dead space, the shape of the tank and the ratio between the width and depth of the water surface are restricted.

(e) Since oxygen is supplied from the outside air, especially in cold regions, the water temperature drops too much and deviates from the activity temperature range of purifying microorganisms, resulting in a significant drop in sewage treatment capacity.

(f) Since the aerator is generally installed in the center of the tank,
Repair workability cannot be said to be good, and there are cases where it is necessary to install a crane, etc.

(g) When using a float type aerator, if the suction port is too close to the tank bottom, it will stick to the bottom of the tank, causing the aerator body to sink and water spraying to be impossible. is also limited to some extent.

In addition, 10 is a float type aerator main body, 11 is a float, 12 is an arm, M is a motor, 0 is treated wastewater, D
1 is a sludge deposit, 100 is a tank, and 15 is a suction port.

In addition, in order to increase the oxygen supply efficiency, a combination type aerator that has a blower device and a stirrer in one tank has been devised, but (a) Two power sources, stirring power and blower power, are required. increases.

(b) A large installation space is required.

(c) The mechanical life of the rotating part of the stirrer is short in water, and repair workability is also poor.

Due to these drawbacks, the implementation rate is not very high.

(Objectives of the present invention) The objects of the present invention are: (a) To enable dissolved oxygen to be controlled during continuous operation; (b) To improve circulation efficiency by sucking up sewage from the bottom of the tank and turning it into sludge. An object of the present invention is to provide an aeration tank that is capable of: (c) preventing sludge accumulation by increasing stirring efficiency;

(Structure of the Invention) The technical means of the present invention taken to achieve the above object are as follows.

Regarding the first invention, the aerator is provided with a suction port in contact with or close to the tank bottom and is equipped with an adjustment device for adjusting the amount of water sprayed, and the aerator is installed in the tank. The second invention has an aerator with a suction port disposed in contact with the tank bottom or close to the tank bottom and an adjustment device for adjusting the amount of water sprinkled. The aerator is fixed to the tank, and a water wheel or turbine is provided within a range where water can be sprayed from the water sprinkling port of the aerator, and the water wheel or turbine is connected via a transmission means to a stirring member that stirs the bottom of the aeration tank; It is.

(Example) The present invention will be explained in more detail based on the example shown in the drawings.

FIG. 1-1 is an explanatory diagram showing an embodiment of the first invention.

1 is an air letter, which is fixed to the aeration tank and prevents the sludge from sticking to the bottom of the tank when it is sucked in. The suction port 5 of the aerator 1 is arranged close to the tank bottom, and
I am trying to suck up the sludge from 1. The suction port 5 can be provided in contact with the tank bottom 101 as shown in Figure I1-2, but in this case, the suction port 5 is provided in the horizontal direction so that the suction port 5 does not contact the tank bottom 101. .

The outlet of the aerator 1 is equipped with a valve 2 for adjusting the amount of water sprayed. A nozzle 4 is formed at the discharge port so that the sludge can be sprayed far away.

A motor M is provided at the top of the aerator 1, and the motor M is connected to an inlet roller 3 provided inside the aerator 1.

Therefore, an impeller 3 rotated by a motor M installed at the top of the aerator body 1 sucks up treated wastewater O from a suction port 5 located near the bottom of the tank, and sprays water through a nozzle 4 toward the liquid surface of the tank. . The amount of water sprinkled can be easily adjusted by opening and closing the valve 2. The required power is also almost the same as a float type aerator.

Unlike the float type, the aerator 1 is fixed to the tank wall, and even if the suction port 5 is provided close to the bottom of the tank, the water spraying part will not sink due to suction.

The aerator 1 may be installed inside the tank as in the embodiment, or the aerator 1 may be installed outside the tank without any problem as long as the suction port 5 is installed inside the tank. This allows selection according to conditions, improves repair workability, and is suitable for expansion.

Furthermore, the water temperature may be controlled and adjusted by steam piping to the aerator 1.

3 and 4 are cross-sectional views showing other embodiments of the nozzle section, in which a rotatable kite valve 9 is provided at the discharge port of the nozzle 4.

Therefore, when reducing the amount of oxygen supplied, the guide valve 9 is adjusted downward so that the water flow is directed downward, as shown in FIG. 3, to shorten the contact time with air.

When increasing the amount of oxygen supplied, the guide valve 9 is directed upward as shown in FIG. 4 to lengthen the contact time between the water flow and the air.

According to this embodiment, the contact time between the water flow and the air can be adjusted steplessly within a certain range.

FIG. 2 is an explanatory diagram showing an embodiment of the second invention.

In the present invention, in addition to the first invention, a water wheel or turbine 6 is further provided within a range where water can be sprayed from the water sprinkling port of the aerator 1,
The water wheel or turbine 6 is connected via a transmission belt 8 to an agitator 7 that stirs the bottom of the aeration tank.

Then, the water sprinkling from the nozzle 4 turns a water wheel or turbine 6, which is used as a power source to operate the agitator 7 which is rotated by a transmission belt 8.

That is, since the tank bottom 101 is stirred by the stirrer 7, the accumulation of sludge is prevented and the retention rate of bubbles is increased, so that the oxygen supply efficiency is also increased.

The stirring device in this example does not require any new power for stirring and has a simple structure, so it is very useful as a device for increasing the oxygen supply efficiency of the aeration tank of the first invention.

(Effects of the Invention) The present invention improves the circulation efficiency of the aeration tank with the above configuration, and the amount of circulating water can be easily adjusted, so that the following effects are produced.

(a) Dissolved oxygen can be controlled during continuous operation, so there is no need for intermittent operation.

(b) Good circulation efficiency as wastewater is sucked up from the bottom of the tank.
Since the dead space is reduced, sludge accumulation can be prevented.

(C) Currently, overloading of wastewater treatment equipment is a problem, and there is an urgent need to expand the equipment.However, on the other hand, especially in large cities, due to land shortages and rising land prices, there is no choice but to aim for three-dimensional equipment. I don't get it.

Therefore, the present invention, which does not require much installation space, has good workability for repairs, etc., and is suitable for expansion can solve this problem.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, and FIG. 1-1 is a detailed explanatory diagram of the first invention, FIG. 1-2 is an explanatory diagram showing a state where the suction port is provided in contact with the bottom of the tank, and FIG. Fig. 2 is an explanatory diagram showing an embodiment of the second invention, Figs. 3 and 4 are explanatory diagrams of the dovetail surface of the nozzle section, Fig. 5 is an explanatory diagram of a blower type aeration tank, and Fig. 6 is a surface agitation type ( It is an explanatory view of a float type aeration tank. l: Aerator 5: Suction port Patent applicant: Akira Kitajima Patent attorney representing Tanane: Katsuhiko Kajiwara

Claims (1)

[Claims] 1. It has an aerator 1 with a suction port 5 disposed in contact with the tank bottom or in close proximity to the tank bottom, and equipped with an adjustment device for adjusting the amount of water sprayed. An aeration tank characterized in that l is fixed to the tank. 2. It has an aerator 1 with a suction port 5 disposed in contact with or close to the tank bottom and an adjustment device for adjusting the amount of water sprayed, and the aerator 1 is fixed to the tank. , an aeration tank in which a water wheel or turbine is provided within a range where water can be sprayed from the water sprinkling port of the aerator 1, and the water wheel or turbine is connected via a transmission means to a stirring member that stirs the bottom of the aeration tank.