JP7693166B2 - Saturated water generator - Google Patents

Description

The present invention relates to a device that is installed in lakes and marshes, fish and shellfish farms, wastewater treatment plants, etc., and generates water (saturated water) in which the amount of dissolved oxygen has reached a saturated state, and in particular to a saturated water generating device that can generate saturated water efficiently with a simple structure.

Organic sludge present at the bottom of ponds, marshes, etc. is decomposed by microorganisms, but if the amount of dissolved oxygen in the water is low, the organic sludge is decomposed anaerobicly, resulting in the production of sulfides, methane gas, etc. In order to prevent the production of these harmful substances, technology is needed to increase the amount of dissolved oxygen in the water, and several inventions and ideas regarding this have already been disclosed.
For example, Patent Document 1 discloses an invention entitled "Underwater Oxygen Supply Device," which relates to a device that is installed underwater for the purpose of improving water quality by supplying oxygen to oxygen-poor water areas.
The invention disclosed in Patent Document 1 has a structure comprising a dissolution tank that is placed underwater and discharges the obtained oxygen-dissolved water to any water depth, a pump that draws in water from any water depth and supplies it to the dissolution tank, gas injection means that injects oxygen-containing gas into the pumped water on the suction and discharge sides of the pump, and a float body that is placed on the water surface of a lake or pond with the pump installed.
With this structure, a pump is installed near the top of the dissolving tank which is placed underwater, so that the pressure in the dissolving tank can be increased by utilizing water pressure, and undissolved gas can be returned to the gas injection means, thereby promoting effective use of the gas.

Furthermore, Patent Document 2 discloses an invention entitled "Deep Layer Aeration Device" that is capable of reliably carrying out emergency exhaust through an emergency exhaust pipe without being affected by the pressure difference between the inside and outside of the aeration body or by suspended solids.
The invention disclosed in Patent Document 2 comprises an aeration body that is moored to the bottom of a lake such as a dam lake and circulates deep water near the bottom of the lake by aeration, an exhaust pipe and an emergency exhaust pipe installed on the top of the aeration body, and a float valve that is installed at the lower end opening of the emergency exhaust pipe and moves up and down according to changes in the water level inside the aeration body, the upper end opening of the emergency exhaust pipe being installed near the outside of the aeration body and the lower end opening being installed below the lower end opening of the exhaust pipe and below the normal water level of the air storage chamber inside the aeration body, the float valve is structured so that under normal circumstances when the water level is higher than the height of the lower end opening of the emergency exhaust pipe, the float valve closes the lower end opening of the emergency exhaust pipe by buoyancy, and in emergency circumstances when the water level is lower than the height of the lower end opening of the emergency exhaust pipe, the float valve opens the lower end opening of the emergency exhaust pipe.
The invention disclosed in Patent Document 2 does not have a structure in which the valve is opened and closed by the pressure difference between inside and outside, but a structure in which the float valve inside the aeration body is opened and closed by the rise and fall of the water level, so there is no need to adjust the opening and closing pressure. Therefore, emergency exhaust can be performed reliably. In addition, since the float valve is located inside the aeration body, there is no risk of floating mud and sand clogging the operating parts, or floating objects such as fallen leaves and plastic bags blocking the opening of the valve, so emergency exhaust can be performed reliably.

Furthermore, Patent Document 3 discloses an invention entitled "Submersible Aeration and Stirring Device," which is installed in a water tank of a wastewater treatment facility or the like and stirs and aerates the water in the tank.
The invention disclosed in Patent Document 3 comprises a rotating cone that is bowl-shaped and flared downwards, with its opening facing downwards, a compressed air chamber formed inside the rotating cone, and a bottom straightening plate with a flat, disc-shaped upper surface disposed below the rotating cone, with the vertical gap between the lower end of the periphery of the opening of the rotating cone and the upper surface of the bottom straightening plate, and a number of narrow slits formed around the entire periphery of the opening of the rotating cone serving as an outlet for the compressed air stored in the compressed air chamber.
With such a structure, a large amount of fine bubbles are generated by shearing due to the rotational force of the rotating cone, which increases the contact area with water, thereby improving the efficiency of oxygen dissolution.

JP 2005-230713 A JP 2012-61423 A Patent No. 6600779

The invention disclosed in Patent Document 1 has a structure in which water into which oxygen has been injected by a gas injection means is supplied into a dissolving tank, but such a structure does not allow the dissolved oxygen concentration in the water to be sufficiently increased. Also, Figure 1 and the specification state in Example 1 that water ejected from a nozzle into the dissolving tank and colliding with a baffle plate is violently foamed, thereby increasing the gas-liquid contact surface area, but it is difficult to increase the dissolved oxygen concentration even by foaming the water into which oxygen has been injected.
In addition, while the invention disclosed in Patent Document 2 has the effect of being able to reliably perform emergency evacuation, aeration using an aeration pipe alone cannot efficiently increase the dissolved oxygen concentration in the water.
Furthermore, the invention disclosed in Patent Document 3 has a structure that generates and diffuses a large amount of fine bubbles, but it is difficult to sufficiently increase the dissolved oxygen concentration in water using a method that generates fine bubbles.

The present invention was made to address these conventional problems, and aims to provide a saturated water generating device that can efficiently generate water saturated with oxygen in lakes and ponds, fish and shellfish farms, wastewater treatment plants, etc., using a simple structure, thereby sufficiently increasing the dissolved oxygen concentration in the water.

In order to achieve the above-mentioned object, the saturated water generating apparatus of the first invention comprises a container whose bottom and sides are closed and which has a first drainage outlet at the bottom through which treated water is discharged, and in which a gas phase is formed at the top by a gas containing at least oxygen, a water-conducting member which is placed in the container with its opening facing upwards, and whose outline, when the inner surface continuing to the opening is viewed from the side, has a shape in which a portion of an egg-shaped line has been cut out, a nozzle which sprays water from above onto the inner surface near the opening, a water supply pipe which has the nozzle connected to its tip, and a water supply pump which has a discharge outlet connected to the base end of the water supply pipe, and which is characterized in that treated water is stored in the lower part of the container.
Incidentally, an oval line is also called a convex closed curve, and is defined as a single closed curve on a plane in which, for any line segment connecting any two internal points, all points on that line segment are also inside the curve. However, the oval line in the first invention also includes a nearly oval line in which part of the curve has been replaced with a straight line.
In the first invention, when water is jetted from a nozzle toward the inner surface of the water-guiding member near the opening, the water descends along the inner surface of the water-guiding member while entraining the gas forming the gas phase at the top of the container, then reverses at the bottom of the inner surface, and rises again along the inner surface of the water-guiding member. After that, part of the water and air bubbles that reach the vicinity of the opening of the water-guiding member are pushed downwards in the water-guiding member by the water jetted from the nozzle, and the rest overflow from the opening of the water-guiding member. Then, the water and air bubbles that have been forced downwards in the water-guiding member descend along the inner surface of the water-guiding member while entraining the gas again, then reverses at the bottom, and rises again, and near the opening, they are divided into water and air bubbles that are pushed downwards in the water-guiding member again by the water jetted from the nozzle, and water and air bubbles that overflow from the water-guiding member.

In this way, in the first invention, the water sprayed from the nozzle repeatedly rises and falls along the inner surface of the water-conducting member while entraining oxygen-containing gas, filling the water-conducting member with air bubbles. This increases the amount of oxygen contained in the air that dissolves in the water, eventually producing water in which the amount of dissolved oxygen has reached a saturated state (saturated water). In addition, the saturated water that is produced inside the water-conducting member overflows from the opening and moves downwards in the water-conducting member is discharged from the first drain outlet to the outside of the container as treated water.

The second invention is characterized in that, in the first invention, it comprises an air supply pipe for supplying gas into the container and a compressor connected to the base end of the air supply pipe, the container has a closed top and is provided with a water supply inlet, an air supply inlet and an openable and closable exhaust port at the top, and the ends of the water supply pipe and the air supply pipe are inserted into the container through the water supply inlet and the air supply inlet, respectively.
In the second invention, in addition to the effect of the first invention, since the top surface of the container is closed, by supplying air pressurized higher than atmospheric pressure by a compressor into the container, a gas phase whose pressure is higher than atmospheric pressure is formed inside the container.

The third invention is characterized in that, in the second invention, the container is installed so that at least a portion of it is submerged in water, the bottom is open instead of having a first drain outlet, and the water supply pump is an underwater pump.
In the third invention, in addition to the effects of the second invention, the pressure of the gas phase formed in the container can be changed by changing the water depth at which the container is placed, and the position of the gas-liquid boundary surface is determined by the position of the exhaust port relative to the container. Also, in the third invention, when gas is continuously supplied into the container from the air supply pipe with the exhaust port open, excess gas is discharged from the exhaust port, and the gas in the container is constantly replaced, thereby maintaining a constant composition.

The fourth invention is characterized in that, in the third invention, it comprises a pump pressure tank in which an underwater pump is housed, a first water supply passage installed underwater parallel to the vertical direction, the lower end of which is connected to the pump pressure tank and the upper end of which is open, a second water supply passage installed underwater parallel to the horizontal direction, the one end of which is connected to the pump pressure tank, and a strainer connected to the other end of the second water supply passage.
In the fourth invention, when the submersible pump is operated to supply water into the container through the water supply pipe, negative pressure is created in the pump pressurization tank, causing the water in the first water supply passage to move downward and the water in the second water supply passage to move toward the pump pressurization tank. As the water in the second water supply passage moves, the water around the strainer is sucked into the second water supply passage. In other words, in addition to the action of the third invention, the fourth invention has the action that as the water in the pump pressurization tank is sucked in by the submersible pump, the water in the second water supply passage moves toward the pump pressurization tank, and the water around the strainer is sucked into the second water supply passage.

A fifth invention is the invention according to any one of the first to fourth inventions, characterized in that the water guide member is made of a bent plate material.
The fifth invention has the effect of the first to fourth inventions, and further has the effect that the water guide member has a simple structure and is therefore inexpensive to process.

The sixth invention is characterized in that, in place of the container, the first invention includes a pressurized tank having a second drain outlet at the bottom through which the treated water is discharged, and a gas phase formed at the top by gas containing at least oxygen and having a pressure higher than atmospheric pressure, an air supply pipe for supplying gas into the pressurized tank, a compressor connected to the air supply pipe, and a drain pipe connected to the second drain outlet for discharging the treated water accumulated in the pressurized tank, and the water-guiding member is installed in the pressurized tank with its opening facing upwards.
In the sixth invention, a water-conducting member is installed inside the pressurized tank instead of a container, and therefore in addition to the effect of the first invention, it has the effect of easily forming a gas phase with a higher pressure inside the pressurized tank and in the upper part of the water-conducting member than in the case of the second invention.

A seventh aspect of the present invention is the sixth aspect of the present invention, wherein the water guide member has a bent plate material and a pair of side plates closing both side surfaces of the plate material.
In the seventh aspect of the invention, in addition to the effect of the sixth aspect of the invention, the water guide member has a simple structure and is therefore inexpensive to process.

According to the first invention, water saturated with oxygen (saturated water) can be efficiently produced, and the dissolved oxygen concentration in the water can be sufficiently increased. In addition, since the first invention has a simple structure, it can be manufactured at low cost. Furthermore, if the top of the container is open, the pressure of the gas phase formed on the top of the container becomes equal to atmospheric pressure, and the container does not need to be pressure-resistant, which can further reduce manufacturing costs.

The second invention has the effect of producing, in addition to the effect of the first invention, treated water having a higher dissolved oxygen concentration than the first invention in a single pass by spraying water from a nozzle toward the inner surface of the water-conducting member near the opening when a gas phase with a pressure higher than atmospheric pressure is formed in the container.

In the third invention, the pressure of the gas phase formed in the container changes depending on the water depth at which the container is placed, so there is no need for a control mechanism or the like to keep the pressure constant, and since the position of the gas-liquid boundary surface is determined by the position of the exhaust port relative to the container, no sensor is needed to detect the position of the gas-liquid boundary surface, so in addition to the effects of the second invention, there is an effect of reducing manufacturing costs. In addition, in the third invention, if gas is continuously supplied into the container from the air supply pipe with the exhaust port open, the gas in the container is constantly replaced and its composition is kept constant, so there is an effect that the dissolved oxygen concentration of the treated water discharged from the container is less likely to fluctuate. Furthermore, since the bottom of the container is open and the same water pressure is applied to the inner and outer surfaces of the container, there is no need to make the container pressure-resistant. Therefore, according to the third invention, manufacturing costs are further reduced.

When a strainer is attached to one end of a water supply pipe and the other end is connected to the suction port of a submersible pump, the range in which the strainer can be installed is determined by the suction capacity of the submersible pump. For example, if the suction capacity of the submersible pump is low, the strainer must be installed near the submersible pump. In contrast, in the fourth invention, when the submersible pump sucks in the water inside the pump pressure tank, the water in the second water supply line moves toward the pump pressure tank, and the water around the strainer is sucked into the second water supply line regardless of the suction capacity of the submersible pump.
That is, in addition to the effects of the third invention, the fourth invention has the effect that when the pump pressure tank and the second water supply line are installed at the bottom of a pond, swamp, etc., the strainer is installed away from the submersible pump, regardless of the suction capacity of the submersible pump, thereby making it possible to treat a wide range of water. If the container is installed at the same height as the strainer, the temperature difference between the low-layer water sucked into the second water supply line from the strainer and the treated water discharged from the container is small, making it difficult for the treated water to mix with the middle or upper layer water, making it possible to treat only the water in the low-layer water area.

The fifth invention has the effect of reducing manufacturing costs, in addition to the effect of any one of the first to fourth inventions, since the water guide member has a simple structure and low processing costs.

According to the sixth invention, in addition to the effects of the first invention, when a gas phase with a higher pressure than that of the second invention is formed in the pressurized tank, water is sprayed from a nozzle toward the inner surface of the water-conducting member near the opening, and treated water with a higher dissolved oxygen concentration than that of the second invention can be produced in one pass. In addition, in the sixth invention, the upper surface of the water-conducting member is open, and the pressure of the gas present therein is equal to the pressure of the gas forming the gas phase in the pressurized tank, so there is no need to make the water-conducting member have the same pressure-resistant structure as the pressurized tank. Therefore, according to the sixth invention, it is possible to reduce manufacturing costs by making the water-conducting member a simple structure.

The seventh invention has the effect of reducing manufacturing costs, in addition to the effect of the sixth invention, because the water guide member has a simple structure and low processing costs.

1A and 1B are a front view and a side view, respectively, showing the appearance of a saturated water generating apparatus according to a first embodiment of the present invention. FIG. 2A is a schematic diagram for explaining the operation of the saturated water generating apparatus shown in FIGS. 1A and 1B, and FIG. 2B is a front view of a modified example of the saturated water generating apparatus. 1A is an external view of a saturated water generating apparatus according to a second embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line AA in FIG. 3(a) is an external oblique view of the water-guiding member shown in FIG. 3(a) and FIG. 3(b), FIG. 3(b) is an external oblique view of a modified example of the water-guiding member, and FIG. 3(c) is a cross-sectional view taken along line B-B in FIG. 3(b). FIG. 11 is an external view of a saturated water generating apparatus according to a third embodiment of the present invention. FIG. 13 is an external view of a saturated water generating apparatus according to a fourth embodiment of the present invention. 3 is a graph showing the relationship between the amount of oxygen dissolved in water (DO value) treated by the saturated water generating apparatus shown in FIG. 2(b) and water depth.

The saturated water generating device of the present invention will be described with reference to Figures 1 to 7. In the following description, expressions such as "upper end", "lower end", "bottom plate", and "bottom surface" are used, assuming that the saturated water generating device will be actually installed.

1(a) and 1(b) are a front view and a side view, respectively, showing the appearance of a saturated water generating apparatus 1a according to a first embodiment of the present invention.
As shown in Figures 1(a) and 1(b), the saturated water generating apparatus 1a includes a container 2 having a bottom plate 2a having an open top surface 2f and a rectangular shape in a plan view and a bottom surface 2c and a side surface 2e closed by four side plates 2b, a water guide plate 3 bent so as to have a shape in which a part of an oval shape has been cut out in a side view and installed inside the container 2 with an opening (the part sandwiched between a pair of ends 3a, 3a, which corresponds to the opening 9a shown in Figure 4(a)) facing upward, a nozzle 4 that sprays water from above onto the inner surface 3b near the opening, a water supply pipe 5 to which the nozzle 4 is connected at its tip 5a, a water supply pump (not shown) having a discharge port connected to the base end of the water supply pipe 5, and an overflow pipe 6 connected to a first drain port (not shown) provided in the side plate 2b near the bottom plate 2a.
The water guide plate 3 has both sides closed by a pair of side plates 2b, 2b parallel to each other, and is installed inside the container 2 without contacting the side plate 2b farthest from the opening out of the pair of side plates 2b, 2b perpendicular to the side, and in a state in which one of the inner surfaces 3b near the opening to which water is sprayed by the nozzle 4 faces upward. When the inner surface 3b of the water guide plate 3 continuing to the above-mentioned opening is viewed from the side, its outline has a shape in which a part of an oval line has been cut out, and it is desirable that the cut-out part be the part of the oval line with the smallest radius of curvature, as shown in FIG. 1(a).

As shown by the arrows in FIG. 1(a), water supplied to the nozzle 4 from the water supply pipe 5 accumulates at the bottom of the container 2, but overflows from the open end 6a of the overflow pipe 6 when the gas-liquid boundary surface (water surface 7) reaches a predetermined height. The top surface 2f of the container 2 is open, allowing the atmosphere to freely enter and exit the interior, so that a gas phase is formed by the atmosphere in the upper part of the container 2 (the part above the gas-liquid boundary surface). In the saturated water generating device 1a, the overflow pipe 6 has the function of maintaining the water surface 7 inside the container 2 at a constant height so that a gas phase is formed in the upper part of the container 2.

Fig. 2(a) is a schematic diagram for explaining the operation of the saturated water generating apparatus 1a. Note that in Fig. 2(a), the side plate 2b disposed in front of the container 2 is not shown.
In the saturated water generating device 1a, the water supplied to the nozzle 4 through the inside of the water supply pipe 5 is jetted toward the inner surface 3b of the water guide plate 3 near the opening as shown by the thin arrow, and while entraining the air forming the gas phase at the top of the container 2, it descends along the inner surface 3b of the water guide plate 3 from near one of the pair of ends 3a, 3a (see FIG. 1(a)) as shown by the thick arrow in FIG. 2(a), then reverses at the bottom of the inner surface 3b and rises again along the inner surface 3b. After that, the water and air bubbles that reach near the other of the pair of ends 3a, 3a are partly pushed downwards of the water guide plate 3 by the water jetted from the nozzle 4, and the rest overflows from the water guide plate 3. Then, the water and air bubbles that have been pushed downwards of the water guide plate 3 descend along the inner surface 3b while entraining air again, then reverses and rises at the bottom of the inner surface 3b, and near the opening, they are divided into water and air bubbles that are pushed downwards of the water guide plate 3 again by the water jetted from the nozzle 4 and water and air bubbles that overflow from the water guide plate 3.
In this way, in the saturated water generating apparatus 1a, the water ejected from the nozzle 4 repeatedly ascends and descends along the inner surface 3b of the water guide plate 3 while drawing in the air forming a gas phase in the upper part of the container 2, thereby filling the inside of the water guide plate 3 with air bubbles. As a result, the amount of oxygen contained in the air that dissolves in the water increases, and finally water in which the amount of dissolved oxygen reaches a saturated state (saturated water) is generated.

The saturated water produced inside the water guide plate 3 overflows from the opening of the water guide plate 3, then flows down along the outer surface 3c (see FIG. 1(a)) of the water guide plate 3, and accumulates in the lower part of the container 2. Thereafter, the saturated water accumulated in the lower part of the container 2 is discharged from the open end 6a of the overflow pipe 6 as treated water (water treated inside the container 2) when the water level 7 reaches a predetermined height.
In this way, the saturated water generating apparatus 1a can efficiently generate water saturated with oxygen (saturated water) and sufficiently increase the dissolved oxygen concentration in the water. In addition, the saturated water generating apparatus 1a has a simple structure and can be manufactured at low cost. Furthermore, in the saturated water generating apparatus 1a, the upper surface 2f of the container 2 is open and the pressure of the gas phase formed therein is equal to atmospheric pressure, so there is no need to make the container 2 a pressure-resistant structure like the pressurized tank 8 described below. This further reduces manufacturing costs.

FIG. 2B is a front view of a saturated water generating apparatus 1b according to a modified example of the saturated water generating apparatus 1a.
As shown in FIG. 2(b), in the saturated water generator 1b, the tip 5a of the water supply pipe 5 and one end of the air supply pipe 16 are inserted into the inside of the container 2 through a water supply port (not shown) and an air supply port (not shown) provided in an upper plate 2d that closes the upper surface 2f of the saturated water generator 1a, an exhaust pipe 17 is connected to an exhaust port (not shown) provided in the upper plate 2d, a compressor 18 is connected to the other end of the air supply pipe 16, and an electromagnetic valve 19a is installed in the exhaust pipe 17.
With this structure, since the top surface 2f of the container 2 is closed, air pressurized higher than atmospheric pressure by the compressor 18 can be supplied to the inside of the container 2. As a result, a gas phase with a pressure higher than atmospheric pressure is formed inside the container 2, and by ejecting water from the nozzle 4 toward the inner surface 3b of the water guide plate 3 near the opening, treated water with a higher dissolved oxygen concentration than that of the saturated water generating device 1a can be generated in one pass.

Fig. 3(a) is an external view of a saturated water generating apparatus 1c according to a second embodiment of the present invention, and Fig. 3(b) is a cross-sectional view taken along line A-A in Fig. 3(a). In order to avoid the figures becoming complicated, only some of the fastening members are labeled with reference numerals in Fig. 3(a) and Fig. 3(b). In addition, the same reference numerals are used for the components shown in Fig. 1(a) and Fig. 1(b), and the description thereof will be omitted as appropriate.
3(a), 3(b) and 4(a), in the saturated water generating apparatus 1c, a second drainage port 20a through which treated water is discharged is provided at the bottom, and three water guide members 9 are installed inside a pressurized tank 8 in which a gas phase is formed at the top by air with a pressure higher than atmospheric pressure. The pressurized tank 8 is composed of a cylindrical tank body 10 having flanges 10a at both ends and installed so that the axial direction is horizontal, and a pair of cover bodies 11, 11 each having a flange 11a, and the flange 10a of the tank body 10 and the flange 11a of the cover body 11 are connected by fastening members 12 consisting of bolts and nuts.
The water-conducting member 9 is composed of a water-conducting plate 3 bent so as to form a shape in which a portion of an oval line has been cut away when viewed from the side, and a pair of side plates 13, 13 which close both sides of the water-conducting plate 3, and is connected to the lower part of the side surface 8a of the pressurized tank 8 via a connector 14 with the opening 9a (see Figure 4(a)) facing upwards.

The three water supply pipes 5 are inserted into the pressurized tank 8 through a water supply port (not shown) at the top of the tank 8. The nozzles 4 are connected to the tips 5a (see FIG. 3(b)) of the three water supply pipes 5, which are inserted into the tank 8 through a water supply port (not shown) at the top of the tank 8, and spray water from above onto the inner surface 3b (see FIG. 3(b)) of the water guide plate 3 near the opening 9a (see FIG. 4(a)). The water supply pipes 5 are connected to the discharge port of a water supply pump 15 at their base ends, and one end of an air supply pipe 16 and one end of an exhaust pipe 17 are connected to an air supply port (not shown) and an exhaust port (not shown) at the top of the side surface 8a of the tank 8. The other end of the air supply pipe 16 is connected to a compressor 18, and an electromagnetic valve 19a is installed in the exhaust pipe 17.
A drain pipe 20 having an electromagnetic valve 19c installed therein is connected to the second drain outlet 20a, and a water level sensor 21 for detecting the upper and lower water levels of the water accumulated inside and a control unit (not shown) for controlling the operation of the compressor 18 and the opening degree of the electromagnetic valve 19a based on the detection result of the water level sensor 21 are installed on the cover body 11 of the pressurized tank 8. That is, the saturated water generating device 1c is structured to keep the height of the water level 7 constant by controlling the amount of gas supplied to the inside of the pressurized tank 8 through the air supply pipe 16 and the amount of gas discharged to the outside of the pressurized tank 8 through the exhaust pipe 17 based on the water level 7 inside the pressurized tank 8 detected by the water level sensor 21.

In the saturated water generating apparatus 1c, unlike the saturated water generating apparatus 1b, a water guide member 9 is installed inside the pressurized tank 8 instead of the container 2, so that a gas phase with a higher pressure than that in the saturated water generating apparatus 1b can be easily formed inside the pressurized tank 8 and above the water guide member 9. In this state, when water is sprayed from the nozzle 4 toward the inner surface 3b near the opening 9a of the water guide plate 3 of the water guide member 9, the pressure of the gas phase is higher than that in the saturated water generating apparatus 1b, so that treated water with a higher dissolved oxygen concentration than that in the saturated water generating apparatus 1b can be generated in one pass. In addition, in the saturated water generating apparatus 1c, the upper surface of the water guide member 9 is open, and the pressure of the air present therein is equal to the pressure of the air forming the gas phase at the upper part of the pressurized tank 8, so that the water guide member 9 does not need to have a pressure-resistant structure similar to that of the pressurized tank 8. In other words, in the saturated water generating apparatus 1c, the water guide member 9 can have a simple structure consisting of the water guide plate 3 and a pair of side plates 13, 13, so that the manufacturing cost can be reduced.

Fig. 4(a) is an external perspective view of the water guide member 9, and Fig. 4(b) is an external perspective view of a modified example of the water guide member 9. Also, Fig. 4(c) is a cross-sectional view taken along line BB in Fig. 4(b).
As shown in Fig. 4(a), the saturated water generating apparatus 1c includes a water guide member 9 having a structure in which the water guide member 9 is composed of a water guide plate 3 and a pair of side plates 13, 13, and an opening 9a is formed by a portion surrounded by a pair of ends 3a, 3a (see Fig. 1(a)) and the pair of side plates 13, 13, but the saturated water generating apparatus 1c is not limited to such a structure. For example, the saturated water generating apparatus 1c may have a structure including a block-shaped water guide member 22 having a hollow portion 23 whose contour line is a shape in which a part of an egg shape has been cut out when the inner surface 23b continuing to the opening 23a is viewed from the side as shown in Figs. 4(b) and 4(c). In this case, the contour line of the inner surface 23b of the hollow portion 23 in the water guide member 22 corresponds to the contour line of the inner surface 3b continuing to the opening 9a in the water guide plate 3 of the water guide member 9.
In addition to the saturated water generator 1c, the saturated water generator 1a and the saturated water generator 1b may also have a structure in which a water guide member 22 is installed inside the container 2 instead of the water guide plate 3. However, when the water guide member 9 equipped with the water guide plate 3 is used instead of the water guide member 22, there is an advantage in that the structure is simple and the processing cost is low, thereby reducing the manufacturing cost.

Fig. 5 is an external view of a saturated water generating apparatus 1d according to a third embodiment of the present invention. Note that the same reference numerals are used to designate the same components as those shown in Figs. 1(a) and 1(b) and 3(a) and 3(b), and the description thereof will be omitted as appropriate.
As shown in Fig. 5, in the saturated water generating apparatus 1d, instead of the first drainage port (not shown) and the overflow pipe 6 in the saturated water generating apparatus 1a, an exhaust pipe 24 with an electromagnetic valve 19b is provided on the side plate 2b of the container 2, which is installed so that the bottom surface 2c is open and at least a part of it is submerged in water, and a water supply port (not shown) and an air supply port (not shown) are provided on the upper plate 2d that closes the upper surface 2f of the container 2. The tip 5a (see Fig. 2(b)) of the water supply pipe 5 is inserted into the inside of the container 2 through the water supply port, and the other end of the air supply pipe 16, one end of which is connected to the air supply port, is connected to the compressor 18. The base end of the water supply pipe 5 is connected to the discharge port of the underwater pump 26, which is supplied with power from an AC power source 25 via a power cable 25a, and the tip 5a (see Fig. 2(b)) of the water supply pipe 5 is connected to a nozzle 4 that sprays water from above onto the inner surface 3b of the water guide plate 3 near the opening 9a. If a pipe is provided that branches off from the air supply pipe 16 and connects to the cavity of the rotation mechanism of the motor of the submersible pump 26, and air pressurized by the compressor 18 is sent to the cavity through this pipe, it is possible to prevent surrounding water from entering the cavity and causing the motor to break down. In this case, the submersible pump 26 does not need to be an expensive one that is pressure resistant, so a general-purpose submersible pump with an inexpensive structure can be used as the submersible pump 26.

In the saturated water generating apparatus 1d, when the inside of the container 2 is filled with water and air pressurized higher than atmospheric pressure using the compressor 18 is supplied into the inside of the container 2 from the air supply pipe 16, part of the water is pushed out from the bottom surface 2c, and the gas-liquid boundary surface (water surface 7) moves downward, resulting in the formation of a gas phase in the upper part of the container 2.
At this time, if the solenoid valve 19b is opened, when the gas-liquid boundary surface reaches the exhaust port (not shown) connected to the exhaust pipe 24, the air supplied to the container 2 from the air supply pipe 16 is discharged to the outside of the container 2 through the exhaust pipe 24, so that the gas-liquid boundary surface does not move downward and remains at the position of the exhaust port (not shown) connected to the exhaust pipe 24. As a result, the pressure of the gas phase formed inside the container 2 is kept constant at a state higher than atmospheric pressure. For example, when the depth from the water surface 7 to the exhaust port (not shown) connected to the exhaust pipe 24 is 3 m, the pressure of the above-mentioned gas phase is about 30 kPa (gauge pressure).

In this way, in the saturated water generating apparatus 1d, the pressure of the gas phase formed inside the container 2 changes by changing the water depth at which the container 2 is installed, so there is no need to install a control mechanism or the like to maintain the gas phase at a constant pressure. In addition, since the position of the gas-liquid boundary surface is determined by the position of the exhaust port relative to the container 2, a sensor for detecting the position of the gas-liquid boundary surface is not required. This reduces manufacturing costs. Furthermore, in the saturated water generating apparatus 1d, if the exhaust port is kept open and air is continuously supplied to the inside of the container 2 from the air supply pipe 16, excess air is discharged from the exhaust port and the air inside the container 2 is constantly replaced. As a result, the composition of the gas phase inside the container 2 is kept constant, so the dissolved oxygen concentration of the treated water discharged from the container 2 is less likely to fluctuate. In addition, since the bottom surface 2c of the container 2 is open and the same water pressure is applied to the container 2 from the inside and outside, there is no need to make the container 2 pressure-resistant. Therefore, the saturated water generating apparatus 1d has the advantage of reducing manufacturing costs compared to the saturated water generating apparatus 1b.

Fig. 6 is an external view of a saturated water generating apparatus 1e according to a fourth embodiment of the present invention. Note that the same reference numerals are used to designate the same components as those shown in Figs. 1(a) and 1(b), 3(a) and 3(b), and 5, and the description thereof will be omitted as appropriate.
As shown in Figure 6, the saturated water generating apparatus 1e is configured in such a manner that, in the saturated water generating apparatus 1d, a pump pressure tank 27 in which an underwater pump 26 is housed, a first water supply passage 28 which is parallel to the vertical direction and is installed underwater with the pump pressure tank 27 connected to its lower end 28a and its upper end 28b open, a second water supply passage 29 which is installed underwater parallel to the horizontal direction and has the pump pressure tank 27 connected to one end, and a strainer 30 connected to the other end of the second water supply passage 29.

In the saturated water generating apparatus 1e, when the submersible pump 26 is operated to supply water into the container 2 through the water supply pipe 5, the inside of the pump pressurization tank 27 becomes negative pressure, so that the water inside the first water supply passage 28 moves downward and the water inside the second water supply passage 29 moves toward the pump pressurization tank 27. Then, as the water inside the second water supply passage 29 moves, the water around the strainer 30 is sucked into the inside of the second water supply passage 29.
When the other end of a water supply pipe having a strainer 30 attached to one end, such as the second water supply passage 29, is connected to the suction port (not shown) of the submersible pump 26, the range in which the strainer 30 can be installed is determined by the suction capacity of the submersible pump 26. For example, if the suction capacity of the submersible pump 26 is low, the strainer 30 must be installed close to the submersible pump 26. In contrast, in the saturated water generating device 1e having the above structure, as the submersible pump 26 sucks in the water inside the pump pressure tank 27, the water inside the second water supply passage 29 moves toward the pump pressure tank 27, and the water around the strainer 30 is sucked into the second water supply passage 29. In other words, when the water inside the pump pressure tank 27 is sucked in by the submersible pump 26, the water around the strainer 30 is sucked into the second water supply passage 29 regardless of the suction capacity of the submersible pump 26, even if the strainer 30 is installed in a location away from the submersible pump 26, so the submersible pump 26 does not require high suction capacity. Therefore, in the saturated water generating device 1e, for example, the strainer 30 can be installed in a location away from the submersible pump 26 even if the suction capacity of the submersible pump 26 is low.

In this way, in the saturated water generating apparatus 1e, when the pump pressure tank 27 and the second water supply line 29 are installed at the bottom of a pond or swamp, the strainer 30 is installed at a location away from the submersible pump 26, regardless of the suction capacity of the submersible pump 26, so that a wide range of water can be treated. In this case, if the container 2 is installed at the same height as the strainer 30, the temperature difference between the low-layer water sucked into the second water supply line 29 from the strainer 30 and the treated water discharged from the container 2 is small, and the treated water is unlikely to mix with the middle layer water or upper layer water, so that only the water in the low-layer water area can be treated. In addition, since the water level 28c inside the first water supply line 28 is lower than the surrounding water level 7 during the operation of the submersible pump 26, in the saturated water generating apparatus 1e, the operating status of the submersible pump 26 installed near the bottom of a lake or swamp can be easily confirmed by visually checking the height of the water level 28c.
In addition, in Figure 6, the container 2 constituting the saturated water generating apparatus 1e is the container 2 constituting the saturated water generating apparatus 1d shown in Figure 5, but the container 2 constituting the saturated water generating apparatus 1b shown in Figure 2 (b) can also be used as the container 2 of the saturated water generating apparatus 1e.

Table 1 shows the saturation amount of oxygen dissolved in distilled water at 1 atmosphere for each temperature. The horizontal columns represent the decimal part of the temperature, and the vertical columns represent the integer part of the temperature. For example, the saturated dissolved oxygen amount (unit: mg/L) when the temperature of distilled water is 9.2°C is the value (11.14) written in the column where the vertical column 9 intersects with the horizontal column 0.2. The saturated dissolved oxygen amount when the pressure of oxygen in contact with distilled water is 1.04 atmospheres (corresponding to a water depth of 0.4 m) can be calculated by multiplying 11.14 by 1.04.
Table 2 shows the theoretical values of the oxygen pressure thus obtained, the water depth and temperature (unit: °C) at which this pressure occurs, and the saturated dissolved oxygen amount (DO value: unit: mg/L). The actual measured values in the table show the results of measuring the dissolved oxygen amount (DO value: unit: mg/L) in the treated water while changing the pressure of the air sprayed from the nozzle 4 in the saturated water generating device 1b. Note that tap water was used instead of distilled water in the experiment.

Figure 7 is a graph in which the theoretical values and actual measured values shown in Table 2 are plotted for each water depth. The horizontal axis indicates water depth, and the vertical axis indicates DO value (unit: mg/L). The black circles indicate actual measured values, and the white diamonds indicate theoretical values.
7 shows that saturated water generating apparatus 1b can generate saturated water corresponding to the air pressure at a desired depth simply by supplying air adjusted to the air pressure at that depth to the inside of container 2 without using pure oxygen gas. In this case, there is no need to use pure oxygen gas, and therefore the cost required for generating saturated water is reduced. In other words, saturated water generating apparatus 1b can easily and inexpensively generate saturated water corresponding to the air pressure at a desired depth. The effect of saturated water generating apparatus 1b can also be achieved in saturated water generating apparatuses 1c to 1e that can increase the pressure of the air inside water-guiding member 9 to a pressure higher than atmospheric pressure.

The present invention can be applied to purifying water by increasing the amount of oxygen dissolved in the water (DO value) in lakes, fish and shellfish farms, wastewater treatment plants, etc.

DESCRIPTION OF SYMBOLS 1a to 1e: Saturated water generating device 2: Container 2a: Bottom plate 2b: Side plate 2c: Bottom surface 2d: Upper plate 2e: Side surface 2f: Upper surface 3: Water guide plate 3a: End portion 3b: Inner surface 3c: Outer surface 4: Nozzle 5: Water supply pipe 5a: Tip 6: Overflow pipe 6a: Open end 7: Water surface 8: Pressurized tank 8a: Side surface 9: Water guide member 9a: Opening 10: Tank body 10a: Flange 11: Cover body 11a: Flange 12: Fastening member 13: Side plate 14: Connector 15: Water supply pump 16: Air supply pipe 17: Exhaust pipe 18: Compressor 19a to 19c: Solenoid valve 20: Drain pipe 20a: Second drain port 21: Water level sensor 22: Water guide member 23: Hollow portion Reference Signs List 23a: Opening 23b: Inner surface 24: Exhaust pipe 25: AC power source 25a: Power cable 26: Submersible pump 27: Pump pressure tank 28: First water supply passage 28a: Lower end 28b: Upper end 28c: Water surface 29: Second water supply passage 30: Strainer

Claims (7)

a container having a bottom and a side that are closed, a first drain outlet that discharges treated water provided at a lower portion, and a gas phase formed at an upper portion by a gas that contains at least oxygen;
A water guide member is installed in the container with the opening facing upward, and when the inner surface continuing to the opening is viewed from the side, the outline of the water guide member has a shape of an oval line with a part of the oval line cut off;
A nozzle that sprays water from above onto the inner surface near the opening;
A water supply pipe with this nozzle connected to the end,
a water supply pump having a discharge port connected to a base end of the water supply pipe;
The treated water is stored in the lower portion of the container ,
The water guide member is configured so that the water sprayed from the nozzle repeatedly rises and falls along the inner surface while entraining the gas that forms the gas phase . an air supply pipe for supplying the gas into the container;
a compressor connected to a base end of the air intake pipe;
The container has a closed top and is provided with a water inlet, an air inlet, and an openable/closable exhaust port at its top.
2. The saturated water generating apparatus according to claim 1, wherein the water supply pipe and the air supply pipe have their ends inserted into the container through the water supply port and the air supply port, respectively. a container whose top and sides are closed, whose upper part is provided with a water inlet, an air inlet, and an openable and closable exhaust port, whose upper part is installed so as to be at least partially submerged in water , into which treated water is discharged from an open bottom part, and in which a gas phase is formed in the upper part by a gas containing at least oxygen;
A water guide member is installed in the container with the opening facing upward, and when the inner surface continuing to the opening is viewed from the side, the outline of the water guide member has a shape of an oval line with a part of the oval line cut off;
A nozzle that sprays water from above onto the inner surface near the opening;
A water supply pipe with this nozzle connected to the end,
a submersible pump having a discharge port connected to a base end of the water supply pipe;
an air supply pipe for supplying the gas into the container;
a compressor connected to a base end of the air intake pipe;
the water supply pipe and the air supply pipe have their respective ends inserted into the container through the water supply port and the air supply port,
The water guide member is configured so that the water sprayed from the nozzle repeatedly rises and falls along the inner surface while entraining the gas that forms the gas phase . a pump pressure tank in which the submersible pump is housed;
a first water supply passage that is installed in the water so as to be parallel to the vertical direction, the first water supply passage having a lower end connected to the pump pressure tank and an upper end that is open;
a second water supply line that is installed in the water so as to be parallel to the horizontal direction and has one end connected to the pump pressure tank;
4. The saturated water generating apparatus according to claim 3, further comprising a strainer connected to the other end of the second water supply passage. The saturated water generating device according to any one of claims 1 to 4, characterized in that the water guide member is made of a bent plate material. a pressurized tank having a second drainage port at a lower portion through which treated water is discharged, and a gas phase formed at an upper portion by a gas containing at least oxygen and having a pressure higher than atmospheric pressure;
an air supply pipe for supplying the gas into the pressurized tank;
A compressor connected to this air intake pipe;
a drain pipe connected to the second drain outlet and configured to drain the treated water accumulated in the pressurized tank;
A water guide member is installed in the pressurized tank with an opening facing upward, and when the inner surface continuing to the opening is viewed from the side, the outline of the water guide member has a shape of an oval line with a part of the oval line cut off;
A nozzle that sprays water from above onto the inner surface near the opening ;
A water supply pipe with this nozzle connected to the end,
and a water supply pump having an outlet connected to the base end of the water supply pipe, wherein the water guide member is configured so that the water sprayed from the nozzle repeatedly rises and falls along the inner surface while entraining the gas that forms the gas phase . The saturated water generating device according to claim 6, characterized in that the water guide member has a bent plate material and a pair of side plates that close both sides of the plate material.

Images