JPS6339315B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) This invention relates to a purification device for closed water bodies that efficiently supplies and purifies air to closed water bodies such as lakes, reservoirs, and inner bays where eutrophication is progressing. .

(Conventional technology) In recent years, in closed water areas such as lakes and inner bays, nutrients such as nitrogen and phosphorus from surrounding basins have been inflowing and
Eutrophication due to accumulation is progressing and becoming a social problem. For this reason, currently the method of regulating organic matter, nitrogen, and phosphorus in the inflow water of closed water bodies is being implemented as an effective means of preventing eutrophication.

(Problems to be solved by the invention) However, since the full details of the eutrophication mechanism have not yet been elucidated and efficient purification methods have not been established, efforts are being made to actively remove closed water areas such as lakes and marshes. At present, almost no attempts have been made to purify or regenerate it.

The present invention was made in view of the current situation, and is the aim of elucidating the entire mechanism of eutrophication and, based on this, devising a device for purifying and regenerating closed water bodies.

(Means for Solving the Problems) The present inventors first considered that the underlying mechanism of eutrophication proceeds as follows.

Lakes and marshes in Japan are classified as temperate lakes, and have two circulation periods throughout the year, in autumn and spring, and two stagnation periods in winter and summer. During the stagnation period, the lake is divided into a surface layer a, a thermocline layer b, and a lower layer c, as shown in Figure 2, and the state of the lake water changes vertically.

In other words, in the surface layer A, phytoplankton proliferates through photosynthesis using sunlight, and dissolved oxygen (DO) becomes supersaturated. low rise c
Plankton that has died in the surface layer A falls down and is oxidized and decomposed, consuming DO and often resulting in anoxic conditions. When this oxygen deficiency occurs,
H ₂ S begins to be generated and at the same time iron, manganese, nitrogen,
Phosphorus is eluted. Then, in the next cycle, the eluted nutrients will diffuse throughout the closed water area, promoting the progress of eutrophication.

Therefore, in order to break this vicious cycle of eutrophication, it is necessary to supply oxygen to the lake bed 100 and prevent the elution of nutrients and the like. Methods for supplying oxygen to lakes and marshes vary depending on the depth of the lake, the progress of eutrophication, etc., but the following two methods can be considered based on their purpose and function.

Circulating aeration method destroys the stratification, so it is suitable for lakes and marshes where the water depth is relatively shallow and there is an extreme lack of dissolved oxygen. It is also effective in improving the water quality of water source ponds that are full of strange-tasting water.

Deep aeration is a method that provides sufficient oxygen to deep water without destroying the stratification, and is effective in preventing the temperature of surface water from dropping in the summer and preventing the outflow of turbid water.

Among these, the present invention has devised an apparatus for purifying and regenerating closed water areas using a circulating aeration method.

FIG. 1 shows the structure of the present invention, which includes a water pump 1, an air chamber 2, an air reservoir 3, and a water supply device 4. Note that 100 indicates the water surface and 101 indicates the lake bottom.

The lift pipe 1 is vertically installed in the water by having the upper end floated on the water surface 100 side by a floating body or the like, and the lower end being moored to the lake bottom 101 side.

The air chamber 2 is connected to the lower end of the lift pipe 1 and allows the air injected into the air chamber to rise into the lift pipe 1, and also takes in low-lying water therein. Its shape is air reservoir 3, which will be described later.
Since it is necessary to install the pipe so that it can roll inside, it is necessary to have a large internal volume to some extent, and in order to allow the air released in the pipe to rise up the pumping pipe 1 efficiently, the upper part is shaped like a funnel. It is preferable that the lower part is open to take in low-lying water.

The air storage shell 3 is provided in the air chamber 2, and is designed to store air inside.When air is collected, it automatically turns over and releases the air after turning over. It is set up in such a way that it returns to its original state.

The water supply device 4 mixes surface water and air, draws the mixed water into the air chamber 2, and blows it out below the air reservoir 3.

(Function) In the surface layer a of lakes and marshes, natural aeration occurs at the lake water surface 100 due to the influence of wind, etc., and there is also the influence of photosynthesis by algae, so dissolved oxygen in the surface water reaches nearly the saturation value. However, due to the heat from the sun, the temperature of the lake's water surface has risen to almost the same temperature as the average temperature.

This high-temperature dissolved oxygen-rich surface water is pumped up by the water supply device 4 (arrow A), air is sucked in (arrow B), mixed, and the mixed water is guided to the air chamber 2. At this time, some of the air dissolves due to the increase in water pressure, and the dissolved oxygen concentration in the mixed water further increases. The bubble-like air that is not completely dissolved rises as shown by arrow C and gradually accumulates in the air reservoir shell 3. On the other hand, the surface water with increased dissolved oxygen flows out as shown by arrow D and mixes with the lower layer water which is deficient in dissolved oxygen and aerates the lower layer water. At the same time, the temperature of low-lying water will also rise. On the other hand, when the air accumulated in the air reservoir shell 3 exceeds a certain amount, the air reservoir shell 3 is automatically reversed due to buoyancy, etc., and at the same time, the air within the air reservoir shell 3 becomes a bullet-shaped bubble. , all at once ejects into the pumping pipe 1 and rises therein as shown by the arrow H. The rise of such bullet-shaped bubbles is performed intermittently. At this time, low-lying water is also sucked in from the bottom of the air chamber 2 as shown by the arrow in the same way as the lift pump.
It is released to the water surface 100 side of the surface layer a as shown by the arrow. The bubble bomb that reaches the water surface 100 ruptures on the water surface 100, causing ripples on the water surface 100 and spreading. The low-lying water that was pumped up at this time along with ripples appeared on the water surface.
0, mixes with surface water and diffuses while being aerated. At the same time, the rise in water temperature can be suppressed by mixing low-temperature low-layer water.

In this way, the present invention maintains the entire closed water area in a circulating state, first aerates the lower layer C with surface water containing a large amount of dissolved air, and then uses the air sent to the lower layer C side together with the surface water to aerate the lower layer water. Water is pumped up to the surface layer A to provide natural aeration.

(Example) Specific examples of the present invention will be described below based on the drawings.

FIG. 3 shows an embodiment of the present invention.
0 and a water supply device 40.

The lift pipe 10 is equipped with a float 13 at its upper part, and its lower part is engaged with a weight 15 on the lake bed 101 by a chain 14 via an air chamber 20, which will be described later, so that it is suspended vertically in the water. It should be noted that this method of vertical installation is only an example, and it goes without saying that other methods of vertical installation may be used.

The air chamber 20 has a hollow part 21 having a larger diameter than the water pumping pipe 10, the upper part of which is constricted in the shape of a funnel and connected to the lower end of the water pumping pipe 10, and the lower part of which is open, from which low-level water can flow. There will be an influx.

The air reservoir shell 30 is made of a cylindrical body having an inclined opening 31 on one side, and a vertical hole 2 on the side of the air chamber 20.
Open 2, insert the other side of the cylinder into it, and attach pin 2.
3, it is rotatably attached to the hollow part 21. That is, the opposite side of the inclined opening 31 is closed,
It is connected to the air chamber 20 by a pin 23 so that when it is filled with water, it tilts due to its own weight so that the inclined opening 31 is at the bottom, and when it is filled with air, it moves upward due to buoyancy. has been done.

The water supply device 40 is composed of a pump 41, an ejector 42, and a water pipe 43, and the ejector 42 sucks air as shown in the arrow B to mix it with the surface water pumped up by the pump 41 in the direction of the arrow A. This mixed water is guided to the lower part of the air chamber 20 through the water pipe 43 and is ejected below the air reservoir shell 30. The inventors investigated the bubble rising speed and obtained a measured value of 0.3 m/s. Therefore, the downward flow velocity in the water pipe 43 was kept at 0.3 m/s or more. Moreover, instead of the pump 41 and ejector 42, (compressed) air may be blown into the water pipe 43 by a blower or compressor.

According to the above-described device, surface water rich in dissolved oxygen can be sent to the lower layer c and aerated. Also, the undissolved air becomes bubbles and accumulates in the air reservoir shell 30, and when a certain amount of air accumulates, the buoyancy pushes the inclined opening 31 upward.
At the same time, the accumulated air turns into bullet-shaped bubbles and blows out into the water pumping pipe 10 all at once. Along with the rise,
Low layer water can be pumped up to the surface layer a. Therefore, it becomes possible to artificially destroy the stratification and maintain the entire water in lakes and marshes in a circulating state.

FIG. 4 shows another embodiment, in which the structure of the air reservoir shells 32, 32a is only different from the previous embodiment, but that part is shown in an enlarged manner (the same structure is used). are given the same number).

The air reservoir shells 32, 32a are composed of two hemispherical cups provided oppositely within the air chamber 20,
It is fixed approximately at the center of a rotating shaft 33 that is rotatably provided in the width direction of the air chamber 20, and is rotatably installed around the rotating shaft 33. In the air reservoir shell 32, undissolved air supplied by the water supply device 40 becomes bubbles and accumulates therein. When a certain amount or more accumulates, the air reservoir shell 32 rotates due to buoyancy and turns the accumulated air into bullet-shaped bubbles. The water is ejected all at once into the pumping pipe 10. Then, the air reservoir shell 32a rotates downward,
Similarly, collect air bubbles in it, and in the same order as above,
Next, a bullet-shaped bubble is ejected.

FIG. 5 shows still another embodiment of the present invention, the basic configuration of which is almost the same as the first and second embodiments, except that water inlets 11 and 11a are provided in the pumping pipe 10. , the structure of the air reservoir shell 34 is different (the same structure is given the same number).

That is, water inlet ports 11 and 11a are provided near the fixed side of the air chamber 20 at the bottom of the water pump 10, and this is because when the air reservoir shell 34, which will be described later, is tilted and a cannonball-shaped bubble is ejected from inside, low-lying water is This is intended to prevent the air reservoir shell 34 from shaking by sucking up the air not only from below the air chamber 20 but also from the water holes 11 and 11a as shown by the arrow.

As shown in FIG. 6, the air reservoir shell 34 is made of a hemispherical bowl with an eccentric weight 35 welded to one end, and the air chamber bottom plate 25, which has a conduction hole 24 in the center, is horizontally placed inside the air chamber 20. and placed on the air chamber bottom plate 25 so as to cover the conduction hole 24. In addition to the hemispherical shape, a rectangular cylindrical shape is also suitable for the shape.

In such a device, when the air accumulated in the air reservoir shell 34 through the conduction hole 24 exceeds a certain amount, the air reservoir shell 34 is lifted by buoyancy. At this time, since the air reservoir shell 34 has been eccentrically set in advance by the eccentric weight 35, it is tilted around the eccentric weight 35 side (indicated by a broken line in the figure), and the air inside the air reservoir shell 34 is shaped like a cannonball. The air bubbles are ejected into the water pump 10 all at once. At the same time, low-level water also flows to the lower part of the air chamber 20 and the water inlets 11, 11 as shown by the arrows.
It is sucked up from a and rises inside the pumping pipe 10.

FIG. 7 shows another embodiment of the invention. This example differs from the above-mentioned examples in that the thermocline b
This is a device that can perform two-stage aeration of the surface layer A and the lower layer C without destroying the surface layer A and the lower layer C. Therefore, as in the third embodiment, a water inlet 1 is provided at the bottom of the pumping pipe 10.
In addition to providing water supply and drainage ports 12 and 11a,
The difference is that a is installed in the middle of the pumping pipe 10 (the same components are given the same numbers).

If the chain 14 is adjusted and installed so that the water supply and drainage ports 12 and 12a are opened at the bottom of the cline b, the rise of the bullet-shaped bubbles will cause the low layer water to flow through the bottom of the air chamber 20 and the water ports 11 and 11a. From the arrow,
The water is sucked in as shown in the figure, moves upward in the water pump 10, and a portion of it is discharged from the water supply and drainage ports 12, 12a to the lower part of the cline b as shown by the arrow R, stirring the low water. When the bullet-shaped bubbles rise further from there, the water in the middle layer is also sucked in from the water supply and drainage ports 12, 12a as shown by arrow N, and is discharged to the upper part of the water pump 10 as shown by arrow T along with the lower layer water. The bubble bomb that reached the water surface of 100 yen bursts at the water surface of 100 yen,
Ripples are generated on the water surface 100 and spread. The low and middle water pumped up at this time creates ripples on the water surface.
00, mixes with surface water and diffuses while being aerated. In this way, the lower layer c and the surface layer a are mixed and stirred simultaneously and separately without destroying the cline layer b, and oxygen is supplied.

An example in which effects similar to those of the above embodiment can be obtained is shown in FIGS. 8 and 9 for reference. Both of these are air reservoir shells 360, 37 in the air chamber 20.
The structure of 0 is different. FIG. 8 shows a configuration in which a hemispherical air reservoir 360 placed on the air chamber bottom plate 25 is engaged with an anti-surfacing rod 362 below the air chamber bottom plate 25 via a chain 361 inserted into the conduction hole 24. It is shown. In such a configuration, the air accumulated in the air reservoir 360 is caused to rise due to buoyancy, and is ejected all at once in the form of bullet-shaped bubbles. At this time, the air reservoir 360 is
By the action of the anti-surfacing rod 362, it is possible to prevent the influence of agitation caused by the low-level water sucked up from below the air chamber 20, so that the water holes 11 and 11a as in the third and fourth embodiments are not required. In addition, in FIG. 9, a cylindrical air reservoir shell 370 with an open bottom is placed on an air chamber bottom plate 250 having a conduction hole 240 in the center, and a flotation prevention fence 371 is provided in the air chamber 20 above it. The configuration is shown. This configuration is similar to the configuration described above, and when the air bubbles become like bullets and are ejected from the air reservoir shell 370 all at once, the air reservoir shell 370 is prevented from rising more than necessary by the floating prevention fence 371. It is something. Further, since this prevents the air reservoir shell 370 from shaking, there is no need to install the water holes 11, 11a.

(Effects of the Invention) According to the purification device of the present invention as described above, it is possible to mix and aerate the dissolved oxygen-rich surface water sent by the water supply device into the lower layer water, and eliminate oxygen deficiency in the lower layer. The air reservoir, which intermittently raises cannonball-shaped air bubbles, allows low-level water to rise from the pumping pipe to the surface layer and aerate above the water surface, making it possible to circulate and aerate the entire closed water area. It has a certain effect.

[Brief explanation of drawings]

Fig. 1 is a schematic sectional view showing the configuration of the present invention, Fig.
The figure is an explanatory diagram showing the situation of closed waters during the stagnation period.
The figure is a sectional view showing one embodiment of the present invention, FIG. 4 is a partially enlarged sectional view showing another embodiment, FIG. 5 is a sectional view showing still another embodiment, and FIG. 6 is a cross-sectional view showing another embodiment. FIG. 7 is a cross-sectional view showing another embodiment, FIG. 8 is a reference view showing an example of an air reservoir having the same effect as the present invention, and FIG. 9 is an enlarged view showing an air reservoir. It is a reference figure which shows yet another example of a shell. In the figure, 1 and 10 are water pumps, 2 and 20 are air chambers,
3, 30, 32, 32a, 34 are air reservoir shells, 4,
Reference numeral 40 indicates a water supply device, 100 indicates a water surface, and 101 indicates a lake bottom.

Claims (1)

[Claims] 1 A lifting pipe vertically installed in water, an air chamber connected to the lower end of the lifting pipe, and an air reservoir rotatably installed in the air chamber, and mixing surface water and air. A purification device for a closed water area, comprising a water supply device that draws water into the empty space and blows it out below the air reservoir.