JPH0691298A - Method for cleaning water area - Google Patents

Abstract

PURPOSE:To clean a water area effectively without generating a dead zone at the middle even when the area is polluted with algae, planktons, and others. CONSTITUTION:A vertical-shaft stirrer 2 is installed at the middle of a water area P1 while horizontal-shaft stirrer 1 at the periphery. Either or both machines have an aeration function to form vertically and horizontally circulating currents. In this way, the water area P1 as a whole is agitated while being kept in an aerobic condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying a water area suitable for preventing the propagation of phytoplankton such as water-bloom and the algae in water areas such as reservoirs, lakes and moats.

[0002]

2. Description of the Related Art Conventionally, as means for aerating and agitating water bodies,
A horizontal axis stirrer as shown in Japanese Patent Laid-Open No. 3-12300 is employed, which is to generate a flow in a horizontal direction to form a circulating flow in a water area. Also in FIG.
Although an air pumping cylinder as shown in Fig. 1 is also used, this method intermittently pumps water at the bottom part by an air lift and discharges it from the upper part of the cylinder.

[0003]

SUMMARY OF THE INVENTION Therefore, Japanese Patent Laid-Open No. 3-12
In the method disclosed in Japanese Patent Publication No. 300, a dead zone occurs in the central part. Even in the known method shown in FIG. 5, a dead zone is likely to occur in the middle layer portion, and the stirring force is not so large.

An object of the present invention is to effectively purify a water area polluted by algae, plankton, etc. without causing a dead zone in the central portion.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object. A vertical axis agitator with a draft tube is provided in the central portion of a body of water, and a horizontal flow is provided along the periphery of the body of water. A horizontal axis stirrer is installed to generate one of the two or both with an aeration function, and the combined operation of the two forms a vertical circulation flow and a horizontal circulation flow to stir and mix the entire water area. By controlling the growth of algae and water-blooms, aeration is performed to keep the whole water area aerobic at all times, and nutrient salts are not eluted from the bottom mud to suppress the growth of phytoplankton. And

[0006]

[Function] A vertical axis stirrer is provided in the central part of the water area, and a horizontal axis stirrer is provided in the peripheral part, and one or both of them are provided with an aeration function to form a vertical circulation flow and a horizontal circulation flow.
Stir and mix while keeping the entire water area aerobic. Therefore, by forming a vertical circulation flow and a horizontal circulation flow and stirring and mixing the entire water area, algae and water-bloom are prevented from being generated, and aeration is performed to keep the entire water area aerobic at all times. By preventing nutrient salt elution from bottom mud,
The growth of phytoplankton can be suppressed.

[0007]

EXAMPLE A method for purifying a water body according to the present invention will be described below with reference to the illustrated example. In FIG. 1, P1 is a water area such as a pond having a required shape, size, and capacity, and a horizontal axis stirrer 1 is provided in the peripheral portion to form a circulation flow along the circumference of the water area. As shown in FIG. 3, this horizontal axis stirrer is composed of a submersible motor 11, a screw 12, and a ventilation pipe 13, and utilizes negative pressure generated by the rotation of the screw 12 to self-supply air on water to perform aeration. Although it can be performed, an underwater mixer capable of only stirring may be used. Depending on the shape and size of the pond, one to several horizontal axis stirrers will be installed.

When a horizontal axis stirrer is used to generate a flow along the circumference of the water body, the central part of the water body becomes a dead zone, and there is almost no flow. Therefore, the vertical axis stirrer 2 is installed in the central part. . As shown in FIG. 4, the horizontal axis stirrer 2 is composed of a motor 21, a stirring blade 22, a draft tube 23, and a float 24. The rotation of the stirring blade 22 sucks the water in the bottom layer in the water area from the lower part of the draft tube, Radiate from the top of the tube. See also FIG.
In order to add the aeration function, the blower 25 is provided on the float 24, and the air is injected into the draft tube directly above the stirring blades in the draft tube by the air diffuser 26. However, when the horizontal axis stirrer has the aeration function. It is not always necessary to provide the air diffuser 26 with the blower 25. It is necessary to determine the number of units to be installed in consideration of the shape of the water area, as in the case of installing two in the case of Fig. 2.

Next, the operation and action of the present invention will be described. When the vertical axis stirrer 2 is operated, an upward flow is generated inside the draft tube 23 by the stirring blade 22, so that the water in the bottom layer is sucked from the radial direction of the lower part of the draft tube. The deeper the water in the bottom layer is, the lower the dissolved oxygen is, and the oxygen becomes insufficient at night compared to during the day. Eject it radially. At this time, around the water surface flows from the center to the outside and descends at the peripheral portion, and in the bottom layer, a circulation flow is formed that flows from the outside to the center and is sucked by the draft tube. However, when only stirring is performed, a vertical axis stirrer that sucks from the upper part of the draft tube and ejects from the lower part of the draft tube may be used, contrary to FIG.

On the other hand, the operation of the horizontal axis stirrer 1 forms a planar circulation flow along the periphery of the water area, and the negative pressure generated by the rotation of the screw 12 causes the air above the water to flow into the aeration pipe tip 13a. Is inhaled from the underwater motor 11, is jetted to the tip of the screw through the hollow shaft of the submersible motor 11, and is cut by the screw edge to form fine bubbles. However, when aeration is performed by the vertical axis stirrer, the horizontal axis stirrer 1 may not perform aeration and only perform stirring.

As described above, since the vertical circulation flow by the vertical axis stirrer and the horizontal circulation flow by the horizontal axis stirrer are combined, the whole water area is stirred and mixed, and the dissolved oxygen supplied is supplied to every corner of the water area. Can be diffused and kept aerobic.

[0012]

According to the present invention, a vertical axis stirrer with a draft tube is provided in the center of a water body, and a horizontal axis stirrer for horizontally generating a flow along the periphery is provided in the peripheral part of the water body. Therefore, one or both of them are equipped with a stirring function, and the combined operation of both forms a combined flow of the vertical circulation flow and the horizontal circulation flow. Such a dead space does not occur, the whole water area can be stirred and mixed, and aeration can be performed to keep the entire water area aerobic at all times, so it is possible to prevent the generation of offensive odors due to anaerobic decay of organic matter, and Since the nutrient salt is not eluted, it has the effect of suppressing the growth of phytoplankton.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment in which a vertical axis stirrer is installed at the center of a required water area and a horizontal axis stirrer is installed at an outer peripheral portion.

FIG. 2 is a plan view of an example in a modified body of water.

FIG. 3 is an explanatory diagram of a horizontal axis stirrer.

FIG. 4 is an explanatory diagram of a vertical axis stirrer.

FIG. 5 is an explanatory diagram of a known example.

[Explanation of symbols]

 1 Horizontal axis stirrer 2 Vertical axis stirrer

Claims (1)

[Claims] 1. A vertical axis stirrer is provided in the central part of the water area and a horizontal axis stirrer is provided in the peripheral part, and one or both of them are provided with an aeration function to form a vertical circulation flow and a horizontal circulation flow. The method for purifying a water body is characterized by stirring and mixing while maintaining the entire water body in an aerobic state.