JP3733484B2 - Defoaming device in wastewater treatment tank - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a defoaming device for an organic wastewater treatment apparatus with foaming for treating sewage such as sewage, manure, and industrial wastewater.
[0002]
[Prior art]
In organic wastewater treatment, there are an aerobic treatment for purifying with an aerobic bacterium and an anaerobic treatment for purifying with an anaerobic bacterium.
[0003]
The aerobic treatment is also called an activated sludge method, and is a method in which air or oxygen is aerated in a treatment tank to remove organic substances in wastewater by aerobic microorganisms in the activated sludge.
[0004]
Anaerobic treatment is a method in which the inside of a tank is made anaerobic and organic substances are removed by anaerobic bacteria in the order of acid fermentation and methane fermentation.
[0005]
Among these, aerobic treatment is aerated, so defoaming is indispensable because foaming occurs due to high-viscosity substances such as proteins and overflows from the inside of the tank.
[0006]
In the past, in order to prevent foaming, a method of adding an inorganic silica-based or organic polymer-based antifoaming agent, a method of erasing with a watering nozzle, or a method of using an antifoaming agent and a watering nozzle in combination has been employed. .
[0007]
[Problems to be solved by the invention]
However, the method using an antifoaming agent requires the cost of the antifoaming agent and requires equipment for quantitatively spraying.
The method using a watering nozzle is suitable for a small amount of foaming, but is not suitable for a deep aeration tank in which a large amount of foam is generated and the opening area is small.
[0008]
The problem to be solved by the present invention is to provide a device that solves the above problems and efficiently eliminates bubbles generated in an organic wastewater treatment tank at low cost.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention is a defoaming device installed at the upper lid opening of an organic wastewater treatment tank with foaming, having an exhaust port at the top, and the lower side of the organic wastewater treatment tank. The outer casing opened to communicate with the upper lid opening, and the outer casing was installed with a gap between the inner wall of the outer casing, the lower side opened, and a plurality of holes were provided on the side a cylindrical rotary member, provided at the bottom of the outer casing, a substantially annular water seal water reservoir plate having a higher dam than the lower end of the smaller diameter than the diameter of the rotating body and the rotating body on the inside It is equipped with.
[0010]
In the present invention, bubbles generated in the upper part of the organic wastewater treatment tank enter the rotating body through the lower opening of the outer casing . Foam that has entered the inside of the rotator collides with the inner wall of the outer casing through a plurality of holes on the side surface of the rotator by centrifugal force generated by the rotation of the rotator. The destroyed foam is divided into gas, solid and liquid, the gas is discharged to the outside through the exhaust port, and the solid and liquid overflow the weir and overflow into the organic wastewater treatment tank .
[0011]
When water is poured up to the upper surface of the weir of the water reservoir plate provided at the bottom of the outer casing, the gap between the lower side of the rotating body and the weir becomes a water-sealed structure, so the clearance between the rotating body and the outer casing is treated with organic wastewater treatment. Isolated from the tank.
[0012]
Outer Further upward and the outer casing portion of the rotary member, a sprinkler for sprinkling the upper surface of the rotating body is provided, by sprinkling the rotating body from the upper portion of the outer casing, the water by a centrifugal force by the rotation of the rotating body Lowers against the inner surface of the casing. As a result, the inner surface of the outer casing is cleaned and water-sealed water is replenished.
[0013]
In addition, by providing a drain pipe that has an upper end lower than the weir inside the water reservoir plate and a lower end connected to the organic wastewater treatment tank so that it penetrates the water reservoir plate, the water spray returns to the organic wastewater treatment tank. The level of water seal water is kept constant.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
1 is a longitudinal sectional view showing an organic wastewater treatment tank equipped with the defoaming apparatus according to the present embodiment, FIG. 2 is an enlarged cross-sectional view of the defoaming apparatus, FIG. 3 is a view taken in the direction of arrow A in FIG. FIG. 5 is a plan view of the lower fixing plate as seen from the line C-C in FIG. 2.
[0015]
In these drawings, an organic wastewater treatment tank 1 is provided with an aeration nozzle 2 and an air supply pipe 3 for aspirating oxygen or air to aerobic microorganisms in the wastewater. An antifoaming device 5 is installed in the opening of the upper lid 4 of the organic wastewater treatment tank 1.
[0016]
As shown in detail in FIGS. 2 to 5, the defoaming device 5 has an outer casing 6 fixed to the opening of the upper lid 4 of the organic wastewater treatment tank 1. An exhaust cylinder 8 serving as an exhaust port 8a is attached to the upper lid 7 of the outer casing 6, and a bearing fixing plate 9 having an opening 9a is attached to the lower part.
[0017]
A rotating shaft 12 is supported at the center of the outer casing 6 by bearings 10 and 11 attached to an upper lid 7 and a bearing fixing plate 9, respectively. A cylindrical rotating body 13 having an opening on the lower side and a plurality of holes 13a on the side surface of the rotating shaft 12 is provided with a gap between the inner wall of the outer casing 6 and an upper fixing plate 14 and an opening 15a. It is supported and fixed by a lower fixing plate 15 (see FIG. 5). When the diameter of the hole 13a was tested for the defoaming effect, 5 to 10 mm was suitable. If it is less than 5 mm, the bubbles are difficult to break, and if it exceeds 10 mm, the result is that small bubbles pass through the holes 13 a as they are.
[0018]
In the lower part of the outer casing 6, there is provided a water sealing water reservoir plate 16 having a weir 16 a having a central portion smaller than the outer diameter of the rotating body 13 and higher than the lower end portion of the rotating body 13.
[0019]
A drain pipe 17 that communicates the inner periphery of the outer casing 6 and the organic wastewater treatment tank 1 is provided at the lower portion of the inner wall of the outer casing 6. A motor 18 for rotating the rotary shaft 12 is attached to the upper lid 7 of the outer casing 6.
[0020]
Further, between the bearing 10 and the upper fixed plate 14 of the rotating body 13, a water sprinkler 19 that sprinkles water toward the upper fixed plate 14 is provided. Water from the organic wastewater treatment tank 1 sucked up by the circulation pump 22 from the water absorption pipe 23 is sprinkled from the water sprinkler 19 through the water supply pipe 20. The water supply pipe 20 is provided with a valve 21. At the top of the sprinkler 19, a foam and spattering prevention plate 24 is provided.
[0021]
The operation of the defoaming device 5 having the above configuration will be described below.
Foam generated in the organic wastewater treatment tank 1 passes through the weir 16a in the center of the water reservoir plate 16 from the opening 9a provided in the bearing fixing plate 9, passes through the opening 15a of the lower fixing plate 15, and enters the inside of the rotating body 13. . The foam that has entered the inside of the rotating body 13 is collided with the inner surface of the outer casing 6 through a plurality of holes 13a on the side of the rotating body 13 by centrifugal force generated by rotating the rotating body 13 at a rotation speed of about 500 rpm. The The destroyed bubbles are divided into gas, solid and liquid, the gas is discharged to the outside through the exhaust port 8a, and the solid and liquid are once stored in the water reservoir 16 and overflow from the weir 16a to overflow the organic wastewater treatment tank 1 It overflows inside. By providing the weir 16a in this way, the water accumulated in the water reservoir plate 16 has a water-sealed structure between the rotating body 13 and the foam inlet inside the weir 16a, and the gap between the rotating body 13 and the outer casing 6 is made organic. It can be isolated from the wastewater treatment tank 1.
[0022]
When the sprinkler 19 sprays the rotating body 13 from the upper part of the outer casing 6, water hits the inner surface of the outer casing 6 by the centrifugal force generated by the rotation of the rotating body 13 and descends. Accordingly, the inner surface of the outer casing 6 can be cleaned and the water seal water can be replenished.
[0023]
Further, by providing a water drain pipe 17 penetrating the gap between the rotating body 13 and the outer casing 6 and the organic waste water treatment tank 1, the water spray can be returned to the organic waste water treatment tank 1, and the level of water seal water Can be kept constant.
[0024]
【The invention's effect】
As described above, the present invention has the following effects.
[0025]
(1) A defoaming device installed at the upper part of the organic wastewater treatment tank, an outer casing having an exhaust port at the upper part and opened so that the lower side communicates with the upper lid opening of the organic wastewater treatment tank, Inside the outer casing, it is installed with a gap between the inner wall of the outer casing, a cylindrical rotating body having a lower opening and a plurality of holes on the side surface, and a bottom part of the outer casing. It is, by a configuration in which a substantially annular water seal water reservoir plate having a higher dam than the lower end of the rotating member smaller diameter and the rotating member than the diameter of the inside, gets inside rotary body The bubbles generated in the organic wastewater treatment tank are efficiently removed by centrifugal force generated by the rotation of the rotating body. Can use and no antifoam agent, so the equipment Together is simplified, the cost can be reduced.
[0026]
(2) When water is poured up to the upper surface of the weir of the water reservoir plate provided at the bottom of the outer casing, the gap between the lower side of the rotating body and the weir becomes a water-sealed structure, so that the gap between the rotating body and the outer casing is organic. It is isolated from the wastewater treatment tank, and it is possible to prevent bubbles from entering the outer casing and perform efficient defoaming.
[0027]
(3) A nozzle for sprinkling water in the outer casing is provided on the upper surface of the rotating body, and water is sprinkled on the rotating body from the upper part of the outer casing, so that water is lowered toward the inner surface of the outer casing by centrifugal force due to the rotation of the rotating body. The inner surface of the outer casing is cleaned and water seal water can be replenished.
[0028]
(4) By providing a drain pipe that penetrates the gap between the rotating body and the outer casing and the inside of the organic wastewater treatment tank, the water spray returns to the organic wastewater treatment tank, and the level of the water seal water is Kept constant.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an organic wastewater treatment tank equipped with a defoaming apparatus according to the present embodiment.
FIG. 2 is an enlarged cross-sectional view of the defoaming apparatus according to the present embodiment.
FIG. 3 is a view taken in the direction of arrow A in FIG. 2;
4 is a view taken in the direction of arrow B in FIG. 2;
FIG. 5 is a plan view of the lower fixing plate as seen from line CC in FIG. 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Organic waste water processing tank 2 Aeration nozzle 3 Air supply pipe 4 Upper cover 5 Defoaming device 6 Outer casing 7 Upper cover 8 Exhaust pipe 8a Exhaust port 9 Bearing fixing plate 9a Opening 10, 11 Bearing 12 Rotating shaft 13 Rotating body 13a Hole 14 Upper part Fixed plate 15 Lower fixed plate 15a Opening 16 Water reservoir plate 16a Weir 17 Drain pipe 18 Motor 19 Sprinkler 20 Water supply pipe 21 Valve 22 Circulation pump 23 Water absorption pipe 24 Foam and water splash prevention plate

Claims (3)

A defoaming device installed at the upper lid opening of an organic wastewater treatment tank with foaming,
An outer casing having an exhaust port at the top, and opened at the lower side so as to communicate with the upper lid opening of the organic wastewater treatment tank;
Inside the outer casing, it is installed with a gap between the inner wall of the outer casing, a cylindrical rotating body with a lower side opened and a plurality of holes on the side surface,
And wherein provided in the bottom of the outer casing, and a substantially annular water seal water reservoir plate having a higher dam than the lower end of the rotating member smaller diameter and the rotating member than the diameter of the inner A defoaming device in a wastewater treatment tank.   The defoaming device in the wastewater treatment tank according to claim 1, wherein a sprinkler for spraying water on an upper surface of the rotating body is provided above the rotating body and inside the outer casing. The wastewater treatment tank according to claim 1 or 2, further comprising a drain pipe having an upper end lower than a height of a weir inside the water reservoir plate and a lower end connected to the organic wastewater treatment tank so as to penetrate the water reservoir plate. Defoaming device.

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