JP2021178272A - Gas-liquid dissolving device - Google Patents

Abstract

To provide a gas-liquid dissolving device that cannot only obtain microbubble liquid including microbubbles therein by dissolving gas in liquid, but also selectively obtain high-concentration dissolved gas liquid including no bubble and high-density dissolved gas.SOLUTION: The gas-liquid dissolving device includes: a dissolving tank 2 in which gas is dissolved in liquid; a liquid supply path 3 which supplies liquid supplied from a liquid supply port 3A to the dissolving tank 2; a venturi mechanism 4 which is provided in the liquid supply path 3; a gas-liquid discharge path 5 which discharges a gas-dissolved solution from the dissolving tank 2; a gas supply path 7 which can select one of a contraction part 4A of the venturi mechanism 4 and a halfway part of the liquid supply path 3 to supply the gas; and a speed controller 6 which is provided in the gas-liquid discharge path 5 to control a discharge speed of the gas-dissolved solution.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gas-liquid dissolving apparatus that selectively produces either a microbubble liquid containing microbubbles in the liquid or a high-concentration dissolved gas liquid containing a high-concentration dissolved gas having a saturation rate of 100% or more in the liquid.

As a device for generating microbubbles in water, for example, in Patent Document 1, water sucked up by a pump from a suction pipe is sent to a pressure tank via a self-priming case and a water pipe connected to the self-priming case. In the pump that drains water from the pressure tank by the discharge pipe, microbubble generation nozzles that generate microbubbles in water are provided in each of the suction pipe and the water pipe, and the microbubble generation nozzles provided in the water pipe are micro-bubbles. A microbubble generator to which a ventilation pipe leading into a pressurized tank for melting bubbles is connected is disclosed.

In this micro-bubble generator, the pressure control valve is opened to discharge water from the discharge pipe, and when the pressure in the pressure tank drops, the pump is operated by the pressure switch attached to the pump, and water is sucked from the suction pipe by the pump operation. At the same time, the microbubble generating nozzle introduces air into the microbubble generating nozzle through the ventilation pipe and automatically supplies the air into the device as microbubbles. In addition, when air collects in the upper part of the pressure tank and the water level drops, the constant water level valve operates, the excess is discharged to the outside of the pressure tank, and the water level is kept constant. The pressure control valve is adjusted so that the maximum release pressure of the discharge pipe is about ^{2.0 to 3.0 kg / cm 2.}

Japanese Patent No. 3785406

By the way, in recent years, next-generation agriculture for efficiently cultivating agricultural products has been attracting attention. It is known that the oxygen concentration in water affects the yield of crops, and the application of the above-mentioned microbubble generator is being studied.

When the present inventors conducted soil cultivation experiments, they found that the optimum dissolved oxygen differs depending on the type of crop and the growth stage. However, in the above-mentioned general pressure-dissolving micro-bubble generator, the main focus is on generating a large amount of smaller bubbles, so it is possible to finely control the dissolved oxygen concentration in water. Therefore, it was not possible to find the optimum cultivation conditions.

Therefore, the present invention can not only dissolve a gas in a liquid to obtain a microbubble liquid containing microbubbles in the liquid, but also a high-concentration dissolved gas liquid containing a high-concentration dissolved gas without containing bubbles in the liquid. It is an object of the present invention to provide a gas-liquid dissolving apparatus capable of selectively obtaining.

The gas-liquid dissolution device of the present invention includes a dissolution tank that dissolves a gas in a liquid, a liquid supply path that supplies the liquid supplied from the liquid supply port to the dissolution tank, and a venturi mechanism provided in the liquid supply path. It is provided in the gas-liquid discharge path for discharging the gas-dissolved liquid from the dissolution tank, the gas supply path in which gas can be supplied by selecting either the throttle portion of the venturi mechanism or the middle of the liquid supply path, and the gas-liquid discharge path. , Includes a speed controller that regulates the discharge rate of the gas solution.

According to the gas-liquid dissolving device of the present invention, the liquid supplied from the liquid supply port is dissolved by changing the solubility of the gas in the liquid by supplying the gas in the throttle portion of the venturi mechanism or in the middle of the liquid supply path. A microbubble liquid containing microbubbles can be obtained by supplying the gas to the tank and reducing the discharge rate of the gas dissolution liquid from the dissolution tank while dissolving the gas in the liquid in the dissolution tank. On the other hand, if the discharge rate of the gas dissolution liquid from the dissolution tank is not reduced, a high concentration dissolved gas liquid containing a high concentration dissolved gas can be obtained without containing bubbles in the liquid.

The microbubble liquid means a liquid containing microbubbles (bubble diameter 1 to 100 μm) in the liquid. Further, the high-concentration dissolved gas liquid means a liquid having no fine bubbles in the liquid but having a higher concentration of dissolved gas than a normal liquid.

The gas-liquid dissolving device of the present invention is a branch path connecting the liquid supply port and the gas-liquid discharge path, and preferably includes a branch path having an on-off valve. This makes it possible to adjust the concentration of the dissolved gas by diluting the gas solution discharged from the gas / liquid discharge path with the liquid.

It is desirable that the dissolution tank discharges the gas dissolution liquid to the gas-liquid discharge passage through the air stone. This makes it possible to prevent large bubbles in the dissolution tank from being mixed into the gas dissolution liquid.

(1) A dissolution tank that dissolves gas in the liquid, a liquid supply path that supplies the liquid supplied from the liquid supply port to the dissolution tank, a venturi mechanism provided in the liquid supply path, and a gas solution from the dissolution tank. The gas / liquid discharge path is provided in the gas / liquid discharge path, the gas supply path in which the gas can be supplied by selecting either the throttle portion of the venturi mechanism or the middle of the liquid supply path, and the gas / liquid discharge path, and the gas solution is discharged. With the configuration including a speed controller that adjusts the speed, not only can the gas be dissolved in the liquid to obtain a microbubble liquid containing microbubbles in the liquid, but also a high-concentration dissolved gas containing no bubbles in the liquid can be obtained. It becomes possible to selectively obtain a high-concentration dissolved gas liquid containing the liquid.

(2) A branch path connecting the liquid supply port and the gas / liquid discharge path, and having a configuration including a branch path having an on-off valve, the gas solution discharged from the gas / liquid discharge path is diluted with the liquid and dissolved. By adjusting the gas concentration, it is possible to obtain a high-concentration dissolved gas liquid containing a high-concentration dissolved gas having an arbitrary saturation rate.

(3) With the configuration in which the dissolution tank discharges the gas dissolution liquid to the gas-liquid discharge passage through the air stone, it is possible to obtain the gas dissolution liquid without the mixing of large bubbles.

It is a schematic block diagram of the gas-liquid mixing apparatus in embodiment of this invention. It is an operation explanatory figure in the case of generating the microbubble water of a medium dissolved oxygen concentration. It is an operation explanatory diagram in the case of generating the microbubble water of a high dissolved oxygen concentration. It is an operation explanatory diagram in the case of generating the microbubble water of a low dissolved oxygen concentration. It is an operation explanatory diagram in the case of generating highly dissolved oxygen water of high dissolved oxygen concentration which does not contain a bubble. It is an operation explanatory diagram in the case of generating the highly dissolved oxygen water of a low dissolved oxygen concentration which does not contain a bubble. It is a graph which shows the relationship between the outlet pressure and the DO value. It is a graph which shows the relationship between the outlet pressure and the flow rate.

FIG. 1 is a schematic configuration diagram of a gas-liquid mixing device according to an embodiment of the present invention.
As shown in FIG. 1, the gas-liquid dissolution device 1 according to the embodiment of the present invention has a dissolution tank 2 that dissolves air as a gas in water as a liquid, and a liquid supply path 3 that supplies water to the dissolution tank 2. , The venturi mechanism 4 provided in the liquid supply path 3, the gas-liquid discharge path 5 for discharging the gas solution from the dissolution tank 2, the speed controller 6 provided in the gas-liquid discharge path 5, and the liquid supply path 3. It has a gas supply path 7 for supplying air to.

The dissolution tank 2 has a liquid supply port 2A, a drainage port 2B, and an exhaust port 2C-1,2C-2. A liquid discharge port 3B at one end of the liquid supply path 3 is connected to the liquid supply port 2A. The other end of the liquid supply path 3 is a liquid supply port 3A, which is connected to a water faucet 10 as a liquid supply source. The pump shown in the middle of the liquid supply path 3 is not essential, but since the water pressure is about 0.4 MPa at the maximum, it is provided to assist this water pressure and increase the dissolved gas concentration. .. A gas / liquid discharge path 5 is connected to the drainage port 2B. Further, in the drainage port 2B, an air stone 8 is arranged in the melting tank 2. The air stone 8 is a porous body having a pore size of 25 to 50 μm. The air stone 8 has a continuous void structure.

An exhaust valve 11 is connected to the exhaust port 2C-1. The exhaust valve 11 is a valve for discharging the air in the melting tank 2. A pressure gauge 12 and a relief valve 13 are connected to the exhaust port 2C-2. The pressure gauge 12 is an instrument that displays the pressure in the melting tank 2. The relief valve 13 is a valve for protecting the melting tank 2. The relief valve 13 is normally closed, and automatically opens when the pressure in the melting tank 2 exceeds a predetermined set pressure.

The liquid supply path 3 is a flow path for supplying the water supplied from the liquid supply port 3A to the dissolution tank 2. The venturi mechanism 4 is provided in the middle of the liquid supply path 3. The gas supply path 7 is located behind (downstream) the throttle portion 4A of the venturi mechanism 4 and the middle of the liquid supply path 3 (in the illustrated example, the liquid supply port 3A between the liquid supply port 3A and the venturi mechanism 4) by the three-way valve 7A. It is connected by branching to the side)). By switching the direction of the three-way valve 7A, the gas supply path 7 selects either the throttle portion of the venturi mechanism 4 or the middle of the liquid supply path 3 to supply air. A check valve 7B is provided between the three-way valve 7A and the throttle portion 4A to prevent backflow from the venturi mechanism 4 to the gas supply path 7.

The speed controller 6 adjusts the discharge rate of the gas solution discharged from the gas-liquid discharge path 5. The speed controller 6 is provided at the end of the gas / liquid discharge path 5. A discharge valve 14 for opening and closing the gas / liquid discharge path 5 is provided in front of (upstream side) of the speed controller 6. Further, a branch path 9 for connecting the liquid supply port 3A and the gas-liquid discharge path 5 is provided between the discharge valve 14 of the gas-liquid discharge path 5 and the liquid discharge port 2B of the dissolution tank 2. An on-off valve 9A is provided at the entrance of the branch road 9.

Further, the gas-liquid dissolving device 1 in the present embodiment includes a compressor 15 that supplies air to the gas supply path 7. The air compressed by the compressor 15 is supplied to the gas supply path 7 through the flow rate control valve 16 and the on-off valve 17. Further, the gas-liquid dissolving device 1 in the present embodiment includes a gas supply path 19 for supplying oxygen gas to the compressor 15 from the gas cylinder 18. The oxygen gas supplied from the gas cylinder 18 to the gas supply path 19 is supplied to the compressor 15 through the flow rate control valve 20 and the on-off valve 21.

Next, the operation of the gas-liquid dissolving device 1 having the above configuration will be described with reference to FIGS. 2 to 6. FIG. 2 is an operation explanatory diagram when producing microbubble water having a medium dissolved oxygen concentration, FIG. 3 is an operation explanatory diagram when generating microbubble water having a high dissolved oxygen concentration, and FIG. 4 is an operation explanatory diagram when producing microbubble water having a low dissolved oxygen concentration. An operation explanatory diagram when generating microbubble water, FIG. 5 is an operation explanatory diagram when generating high dissolved oxygen water having a high dissolved oxygen concentration that does not contain bubbles, and FIG. 6 is an operation explanatory diagram when generating high dissolved oxygen water that does not contain bubbles, and FIG. It is an operation explanatory diagram in the case of generating dissolved oxygen water.

<A-1> Generation of Micro Bubble Water with Medium Dissolved Oxygen Concentration Micro bubble water with medium dissolved oxygen concentration (saturation rate of dissolved oxygen 150 to 250%) is generated by the gas-liquid dissolving device 1 in the present embodiment. In this case, as shown in FIG. 2, the three-way valve 7A is switched so that the air from the gas supply path 7 is supplied to the throttle portion 4A of the venturi mechanism 4, and the on-off valve 9A of the branch pipe 9 and the gas supply path 19 are switched. The on-off valve 21 is closed and the on-off valve 17 of the gas supply path 7 is opened.

As a result, the air supplied from the compressor 15 to the gas supply path 7 through the flow rate control valve 16 and the on-off valve 17 is supplied from the three-way valve 7A to the throttle portion 4A of the Venturi mechanism 4, and is sent from the faucet 10 by the Venturi effect. Efficiently mixed with water (tap water). The mixed water in which the water and the air are mixed passes through the venturi mechanism 4 and is pushed into the dissolution tank 2 from the liquid supply port 2A, and the air is dissolved in the water in the dissolution tank 2.

The pressure of the air-dissolved water dissolved in the dissolution tank 2 is released by opening the discharge valve 14 of the gas-liquid discharge passage 5, and the dissolved oxygen concentration is moderate (saturation rate of dissolved oxygen is 150 to 250%). At this time, the amount of microbubbles in the microbubble water is controlled by rapidly releasing the pressure or gently releasing the pressure by squeezing the speed controller 6. Can be done. Further, the dissolved oxygen concentration in the microbubble water can be controlled by adjusting the amount of air supplied to the gas supply path 7 by the flow rate control valve 16.

<A-2> Generation of Micro Bubble Water with High Dissolved Oxygen Concentration When the gas-liquid dissolving device 1 in the present embodiment is used to generate micro bubble water having a high dissolved oxygen concentration (saturation rate of dissolved oxygen is 250% or more), FIG. The state shown in FIG. 3 is switched to the state shown in FIG. That is, the on-off valve 21 of the gas supply path 19 is opened so that oxygen gas is supplied from the compressor 15 to the gas supply path 7 through the flow rate control valve 16 and the on-off valve 17. As a result, microbubble water having a high dissolved oxygen concentration (saturation rate of dissolved oxygen of 250% or more) is generated.

At this time, by throttled the speed controller 6, the amount of microbubbles in the microbubble water can be controlled by rapidly releasing the pressure or slowly releasing the pressure. Further, the dissolved oxygen concentration in the microbubble water can be controlled by adjusting the amount of oxygen gas supplied to the compressor 15 by the flow rate control valve 20.

<A-3> Generation of Micro Bubble Water with Low Dissolved Oxygen Concentration When the gas-liquid dissolving device 1 in the present embodiment is used to generate micro bubble water with a low dissolved oxygen concentration (saturation rate of dissolved oxygen 100 to 150%), FIG. The state shown in FIG. 2 is switched to the state shown in FIG. That is, the three-way valve 7A is switched so that the air from the gas supply path 7 is supplied to the middle of the liquid supply path 3 instead of the throttle portion 4A of the venturi mechanism 4.

As a result, the air supplied from the compressor 15 to the gas supply path 7 through the flow rate control valve 16 and the on-off valve 17 is supplied from the three-way valve 7A to the middle of the liquid supply path 3, and is supplied from the faucet 10 (tap water). ) And mixed. The mixed water in which the water and the air are mixed passes through the venturi mechanism 4 and is pushed into the dissolution tank 2 from the liquid supply port 2A, and the air is dissolved in the water in the dissolution tank 2.

That is, in the state shown in FIG. 4, since the Venturi effect by the Venturi mechanism 4 cannot be obtained, the air is not efficiently mixed with the water (tap water) sent from the faucet 10, and the dissolved oxygen concentration (dissolved oxygen) is low. It is discharged as microbubble water with a saturation rate of 100 to 150%).

At this time, by throttled the speed controller 6, the amount of microbubbles in the microbubble water can be controlled by rapidly releasing the pressure or slowly releasing the pressure. Further, the dissolved oxygen concentration in the microbubble water can be controlled by adjusting the amount of air supplied to the gas supply path 7 by the flow rate control valve 16.

In addition, in the generation of the microbubble water of <A-1> to <A-3>, in order to generate a large amount of finer microbubbles, it is necessary to adjust the speed controller 6 to a certain appropriate opening degree. However, as a large amount of fine microbubbles are generated, the air dissolved in the water is precipitated, and the dissolved oxygen concentration is lowered. The flow rate control valve 16 or the flow rate control valve 20 is opened to compensate for the lowered dissolved oxygen concentration, and the amount of air pushed into the liquid supply path 3 is adjusted. That is, the amount of microbubbles is adjusted by the throttle amount of the speed controller 6, and the amount of dissolved oxygen is adjusted by the opening degree of the flow rate control valve 16 or the flow rate control valve 20.

<B-1> Generation of High Dissolved Oxygen Water with High Dissolved Oxygen Concentration Not Containing Bubbles High high dissolved oxygen concentration (saturation rate of dissolved oxygen 300% or more) without bubbles by the gas-liquid dissolving device 1 in the present embodiment When generating dissolved oxygen water, for example, the state shown in FIG. 3 is switched to the state shown in FIG. That is, the speed controller 6 is opened or the speed controller 6 is removed. At this time, the on-off valve 21 of the gas supply path 19 is open, and oxygen gas is supplied from the compressor 15 to the gas supply path 7 through the flow rate control valve 16 and the on-off valve 17.

As a result, the air-dissolved water dissolved in the dissolution tank 2 does not generate bubbles due to pressure release by opening the discharge valve 14 of the gas-liquid discharge passage 5, and the air-dissolved water in the dissolution tank 2 remains as it is. Since it is discharged, highly dissolved oxygen water having a high dissolved oxygen concentration (saturation rate of dissolved oxygen of 300% or more) containing no bubbles can be obtained. At this time, the dissolved oxygen concentration of the highly dissolved oxygen water can be controlled by adjusting the amount of oxygen gas supplied to the compressor 15 by the flow rate control valve 20.

<B-2> Generation of highly dissolved oxygen water having a low dissolved oxygen concentration that does not contain bubbles The gas-liquid dissolving device 1 in the present embodiment has a low dissolved oxygen concentration that does not contain bubbles (saturation rate of dissolved oxygen 100 to 300%). When producing highly dissolved oxygen water, the state shown in FIG. 5 is switched to the state shown in FIG. That is, the on-off valve 9A of the branch pipe 9 is opened, and the water sent from the faucet 10 is mixed with the highly dissolved oxygen water discharged from the drain port 2B of the dissolution tank 2.

As a result, highly dissolved oxygen water having a low dissolved oxygen concentration (saturation rate of dissolved oxygen of 100 to 300%) containing no bubbles can be obtained. At this time, the amount of dissolved oxygen in the highly dissolved oxygen water is adjusted by adjusting the amount of water flowing to the branch pipe 9 by the on-off valve 9A and adjusting the amount of air supplied to the gas supply path 7 by the flow rate adjusting valve 16. The concentration can be controlled.

It is not necessary to obtain highly dissolved oxygen water having a low dissolved oxygen concentration (saturation rate of dissolved oxygen 100 to 300%) that does not contain bubbles, and a high dissolved oxygen concentration that does not contain bubbles (saturation rate of dissolved oxygen 300% or more). When the highly dissolved oxygen water of No. 1 and the above-mentioned micro bubble water are generated, the branch path 9 can be omitted.

As described above, according to the gas-liquid dissolution device 1 in the present embodiment, not only can air be dissolved in water to obtain microbubble water containing microbubbles in water, but also high concentration without bubbles in water can be obtained. It is possible to selectively obtain high-concentration dissolved oxygen water containing dissolved oxygen. Further, by diluting the oxygen-dissolved water discharged from the drainage port 2B with water to adjust the dissolved oxygen concentration, it is also possible to obtain a highly dissolved oxygen water containing an arbitrary low-to-high concentration dissolved oxygen. It is possible.

Further, in the gas-liquid dissolution device 1 of the present embodiment, the dissolved oxygen concentration of the microbubble water is also arbitrarily adjusted by the throttle amount of the speed controller 6, the opening degree of the flow rate control valve 16 or the flow rate control valve 20, and the like. It is possible. That is, in the gas-liquid dissolving device 1 in the present embodiment, the dissolved oxygen concentration can be controlled in each of the microbubble water and the highly dissolved oxygen water.

Further, in the gas-liquid dissolution device 1 of the present embodiment, since the dissolution tank 2 discharges the oxygen-dissolved water to the gas-liquid discharge passage 5 through the air stone 8, large bubbles are mixed in the microbubble water and the high-concentration dissolved oxygen water. No.

In the above embodiment, an example in which water (tap water) is used as a liquid and air is used as a gas has been described, but by using other liquids and gases, the gas is dissolved in the liquid and microbubbles are contained in the liquid. It is possible not only to obtain a microbubble liquid containing the above, but also to selectively obtain a high-concentration dissolved gas liquid containing a high-concentration dissolved gas without containing bubbles in the liquid.

Using the gas-liquid dissolving device 1 in this embodiment, the type of water and the DO value were controlled, and the bubble diameter was investigated. The experiment was carried out by setting the water pressure and the air pressure to the same pressure with a regulator, throttle the speed controller 6, and adjust the outlet pressure. The drainage was visually measured, the DO value was measured with a fluorescent dissolved oxygen meter, the bubble diameter was estimated using the Stokes formula, and it was determined that the drainage was microbubble water when the bubble diameter was 1 to 100 μm.

FIG. 7 is a graph showing the DO value when the water pressure and the air pressure are set to each value and the speed controller 6 is throttled to adjust the outlet pressure. FIG. 8 is a graph showing the flow rate when the water pressure and the air pressure are set to each value and the speed controller 6 is throttled to adjust the outlet pressure.

From FIGS. 7 and 8, when the speed controller 6 is throttled and the outlet pressure is 0.3 MPa or more, microbubble water is generated, and when the speed controller 6 is opened and the outlet pressure is 0.2 MPa or less. It can be seen that high-concentration dissolved oxygen water is obtained in.

The gas-liquid dissolving device of the present invention can not only dissolve a gas in a liquid to obtain a microbubble liquid containing microbubbles in the liquid, but also have a high concentration containing a high-concentration dissolved gas without containing bubbles in the liquid. It is useful as a device that can selectively obtain dissolved gas liquid, and in particular, it is useful in the agricultural field (agricultural crop cultivation, gardening, etc.), the food field (aquatic cultivation, sterilization and cleaning in the food processing process, etc.) and the environmental field (water quality). Suitable for improvement and wastewater treatment).

1 Gas / liquid dissolution device 2 Dissolution tank 2A Liquid supply port 2B Discharge port 2C Exhaust port 3 Liquid supply port 3A Liquid supply port 3B Liquid discharge port 4 Venturi mechanism 4A Squeezing section 5 Gas / liquid discharge path 6 Speed controller 7 Gas supply path 7A Three-way valve 7B Check valve 8 Air stone 9 Branch path 9A On-off valve 10 Faucet 11 Exhaust valve 12 Pressure gauge 13 Relief valve 14 Discharge valve 15 Compressor 16 Flow control valve 17 On-off valve 18 Gas bomb 19 Gas supply path 20 Flow control valve 21 Open / close valve

Claims (5)

A dissolution tank that dissolves gas in a liquid,
A liquid supply path that supplies the liquid supplied from the liquid supply port to the dissolution tank, and
The venturi mechanism provided in the liquid supply path and
A gas-liquid discharge path for discharging the gas dissolution liquid from the dissolution tank,
A gas supply path capable of supplying gas by selecting either the throttle portion of the venturi mechanism or the middle of the liquid supply path, and the gas supply path.
A gas-liquid dissolving device provided in the gas-liquid discharge path and including a speed controller for adjusting the discharge rate of the gas-dissolving liquid. The gas-liquid dissolution device according to claim 1, which is a branch path connecting the liquid supply port and the gas-liquid discharge path and includes a branch path having an on-off valve. The gas-liquid dissolution device according to claim 1 or 2, wherein the dissolution tank discharges the gas dissolution liquid to the gas-liquid discharge passage through an air stone. The gas-liquid dissolving apparatus according to any one of claims 1 to 3, further comprising a compressor that supplies air to the gas supply path. The gas-liquid dissolution device according to any one of claims 1 to 4, which is an oxygen gas supply path for supplying oxygen gas to the compressor and includes an oxygen gas supply path provided with a flow rate control valve.

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