JP2000161278A - Gas liquid mixing dissolution device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas liquid mixing dissolution device capable of efficiently and stably mixing a great quantity of gas into liquid so as to be dissolved therein, and of producing a great quantity of gas dissolved liquid high in concentration. SOLUTION: Plural vortex flow pumps 11a and 11b feeding liquid in order, are connected in series by the use of a conduit 31. A conduit 14 taken out of the inside of the bottom part of a floating separation processing tank 13 purifying and treating of polluted material contained in liquid by means of floating separation, is connected with the liquid suction port 12a of the vortex pump 11a at the upstream side through a suction pressure adjusting valve 15, and it is also connected with a gas suction means 16 for sucking gas such as air. A conduit 18 is taken out of a gas liquid discharging port 17b discharging gas liquid mixed material by the use of the vortex pump 11b at the downstream side so as to be inserted into an excess gas separation tank 19 for separating excess gas contained in the gas liquid mixed material. A conduit 21 taken out of the inside of the bottom part of the excess gas separation tank 19 is thereby inserted into the inside of the bottom part of the floating separation processing tank 13 through a discharge pressure adjusting valve 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas-liquid mixing and dissolving apparatus using a vortex pump.

[0002]

2. Description of the Related Art As shown in FIG. 7, a conventional gas-liquid mixing and dissolving apparatus uses a flotation process in which a contaminant in a liquid is floated and separated into a liquid suction port 12 of a vortex pump 11 to purify the liquid. A pipe 14 drawn from the bottom of the tank 13 is a suction pressure adjusting valve.
A gas suction means 16 for sucking a gas such as air is connected to the liquid suction port 12 of the vortex pump 11 in addition to the connection via the liquid suction port 15.

Further, a pipe 18 is drawn out from a gas-liquid discharge port 17 for discharging a gas-liquid mixture in which gas is mixed and dissolved in a liquid by a vortex pump 11, and this pipe 18 is connected to the gas-liquid mixture. A pipe 21 inserted into a surplus gas separation tank 19 for separating surplus gas of
It is inserted through the discharge pressure regulating valve 22 to the center in the bottom of the flotation tank 13.

The gas suction means 16 has a tip of a suction nozzle 26 equipped with a flow meter 23, a check valve 24 and a solenoid valve 25 which can be freely opened in the suction direction, and is inserted into the liquid suction port 12 of the vortex pump 11. ing.

[0005] The excess gas separation tank 19 is provided with an air release valve 27 such as an air release valve on the upper part of the sealed tank body, and this air release valve 27 gradually removes only the excess gas in the liquid to the outside. To be discharged. The gas-liquid mixture in the surplus gas separation tank 19 is in a pressurized state, and is injected into the bottom of the floating separation processing tank 13 through the pipe 21.

[0006] A suction pressure gauge (compound gauge) 28 is provided in the pipe 14 on the suction side of the vortex pump 11, and a discharge pressure gauge 29 is provided in the pipe 18 on the discharge side of the vortex pump 11.

In such a gas-liquid mixing and dissolving apparatus, when a gas such as air is mixed and dissolved in a liquid such as water,
While sucking the clean liquid purified in the flotation treatment tank 13 into the vortex pump 11, the suction pressure adjusting valve 15 is throttled while looking at the suction pressure gauge 28, and the liquid suction port 12 of the vortex pump 11 is set to a negative pressure. The gas is simultaneously sucked from the gas suction means 16. At this time, the flow rate of the gas injected into the liquid is
The adjustment is performed at 23, for example, the gas-liquid ratio is adjusted to 7 to 8%.

The liquid and the gas are stirred and mixed in the vortex pump 11, the discharge pressure is increased by the throttle of the discharge pressure regulating valve 22, and the gas is dissolved under pressure in the liquid. The undissolved surplus gas that has not been dissolved in the liquid is released to the atmosphere from the vent valve 27 of the surplus gas separation tank 19, and the pressurized liquid in which the gas has been completely dissolved is large by the discharge pressure regulating valve 22. The gas that has been rapidly decompressed to atmospheric pressure and dissolved in the liquid
It is released as fine bubbles in the liquid inside 13.

[0009] These fine bubbles adhere to the contaminants floating in the liquid to float and separate the contaminants, thereby purifying the liquid.
This cycle is continuously performed to purify water quality and the like.

[0010]

In this conventional gas-liquid mixing and dissolving apparatus, a single vortex pump is used to simultaneously suck liquid and gas from the suction side of the vortex pump to perform gas-liquid mixing and dissolution. Therefore, due to the influence of the gas sucked from the pump suction side, the flow rate of the flowing liquid and the pump discharge pressure are reduced. For example, the gas injection limit is about 10% in gas-liquid ratio.
If the pressure exceeds the limit, the liquid cannot be sent, so that a large amount of gas cannot be injected.

If the amount of liquid sent and the amount of discharge pressure reduced by gas suction are large, for example, for a microbubble generator, the amount of liquid sent at an actual point of use, which is generally pressurized to 4 kg / cm ² , becomes very large. Since the flow rate becomes small, the operation state becomes extremely unstable, and foaming failure occurs suddenly, there is a problem that the operation operation of the apparatus is troublesome.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a gas-liquid mixed solution capable of efficiently and stably mixing and dissolving a large amount of gas in a liquid to produce a large amount of a high-concentration gas-dissolved solution. It is intended to provide a device.

[0013]

According to the present invention, a plurality of vortex pumps are connected in series and sequentially feed a liquid, and a gas suction is connected to a liquid suction port of an upstream vortex pump. And a gas-liquid mixing and dissolving apparatus comprising:

Since a plurality of vortex pumps are connected in series, the differential pressure per vortex pump with respect to the set pressure can be used at a low pressure equally divided by the number of pumps used, The pump discharge pressure can be increased by the number of times. As a result, the amount of gas suction increases, the amount of reduction in the pump discharge pressure and the amount of liquid supply caused by the gas suction is small, the operating state at the time of gas suction is stable, and the high-concentration gas solution can be efficiently removed. Can be manufactured.

According to a second aspect of the present invention, there is provided a pump main body of a vortex pump, a plurality of impellers rotatably provided inside the pump main body, and respective impellers provided along these impellers. A plurality of stages of boost passages connected in series;
A gas-liquid mixing / dissolving apparatus comprising: a gas suction means connected to a liquid suction port in an upstream pressure passage.

Since the pressure passages along the plurality of stages of impellers are connected in series, the differential pressure per impeller relative to the set pressure is a low pressure divided equally by the number of used impellers. The pump can be used under pressure, and the pump discharge pressure can be increased by the number of times the number of impellers is used. As a result, the amount of gas suction increases, the amount of reduction in the pump discharge pressure and the amount of liquid supply caused by the gas suction is small, the operating state at the time of gas suction is stable, and the high-concentration gas solution can be efficiently removed. Can be manufactured. Furthermore, since a plurality of stages of impellers are provided in the common pump body, the device can be made compact and inexpensive.

According to a third aspect of the present invention, in the gas-liquid mixing and dissolving apparatus according to the first or second aspect, the gas suction means stands above the liquid level in the tank connected to the liquid suction port of the vortex pump. It is formed by a gas suction pipe which is opened up.

Since the operating state at the time of gas suction is stable, a conventional air flow meter or the like used for operation adjustment of the gas suction amount is not required, and the liquid in the tank connected to the liquid suction port of the vortex pump is not required. The gas suction means can be simplified by using only the gas suction pipe which is opened up from the surface.

According to a fourth aspect of the present invention, there is provided the gas-liquid mixing and dissolving apparatus according to any one of the first to third aspects, wherein the vortex pump is connected to a gas-liquid discharge port for discharging a gas-liquid mixture. A surplus gas separation tank for separating the surplus gas in the gas-liquid mixture, and a discharge line disposed over another tank through a restricting means for giving a gas discharge resistance from the sealed upper part of the surplus gas separation tank. It is provided with.

Further, not only the surplus gas in the surplus gas separation tank but also the liquid is discharged to another tank by a discharge pipe through a simple restricting means, so that leakage of the liquid from the conventional surplus gas separation tank is prevented. There is no risk of clogging with impurities in the liquid as in an air vent valve having an opening / closing structure.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS.

FIGS. 1 and 2 show an embodiment of a gas-liquid mixing / dissolving apparatus. As shown in FIG. 1, a plurality of vortex pumps 11a and 11b for sequentially feeding liquid are connected by a pipe 31. They are connected in series.

A line 14 drawn out from the bottom of a flotation tank 13 for purifying the liquid by floating and separating contaminants in the liquid into a liquid inlet 12a of the vortex pump 11a on the upstream side.
Is connected via a suction pressure regulating valve 15, and a gas suction means 16 for sucking a gas such as air is also connected to the liquid suction port 12a of the vortex pump 11a on the upstream side.

Further, a pipe 18 is drawn out from a gas-liquid discharge port 17b for discharging a gas-liquid mixture in which a gas is mixed and dissolved in a liquid by a vortex pump 11b on the downstream side. A line 21 inserted into an excess gas separation tank 19 for separating excess gas in the mixture and drawn out from the bottom of the excess gas separation tank 19 passes through a discharge pressure regulating valve 22 to the flotation separation processing tank. It is inserted to the center in the bottom of 13.

The gas suction means 16 is provided with a flow meter 23, a check valve 24 which can be freely opened in the suction direction, and a suction nozzle 26 which is sequentially equipped with a solenoid valve 25. The tip of the suction nozzle 26 has a liquid suction port 12a of an upstream vortex pump 11a. Has been inserted. In the embodiment using the plurality of vortex pumps 11a and 11b, since the operating state at the time of gas suction is stable, the air flow meter 23, the check valve 24 and the solenoid valve 25 can be removed.

Further, the excess gas separation tank 19 is provided with an air release valve 27 such as an air release valve on the upper part of the sealed tank body, and this air release valve 27 gradually removes only the excess gas in the liquid to the outside. To be discharged. The gas-liquid mixture in the surplus gas separation tank 19 is in a pressurized state, and is injected into the bottom of the floating separation processing tank 13 through the pipe 21.

A suction pressure gauge (compound gauge) 28 is provided in the pipe 14 on the suction side of the vortex pump 11a, and a discharge pressure gauge 29 is provided in the pipe 18 on the discharge side of the vortex pump 11b.

As shown in FIG. 2, each of the plurality of vortex pumps 11a and 11b connected in series by the pipe line 31 has an annular boosting passage 33 formed in the pump body 32. The liquid suction ports 12a and 12b are formed in communication with the inlet 34, and the gas-liquid discharge ports 17a and 17b are formed in communication with the outlet 35 of the pressurizing passage 33.
An isolation portion 36 is formed between 34 and the outlet portion 35.

An impeller 37 is rotatably fitted in the pump body 32. A plurality of small blades 38 and a blade groove 39 between the small blades 38 are provided on the outer periphery of the impeller 37. By rotating a rotary shaft 41 fitted at the center of the impeller 37 by an external motor or the like, these small blades 38 and the blade grooves 39 pass through the pressure passage 33 concentric with the impeller 37. Rotate.

The liquid suction port 12a of the vortex pump 11a on the upstream side
The suction nozzle 26 is screwed into and fixed to a portion that forms
A gas through hole 26a formed inside the suction nozzle 26 is opened to the inlet 34 of the pressurizing passage 33, and the gas flows along the inflow direction of the liquid from the gas through hole 26a. Is introduced.

When the impeller 37 is rotated in the vortex pump 11a on the upstream side, the liquid sucked from the liquid suction port 12a substantially goes around the pressure-raising passage 33 together with the impeller 37, and is pressurized during that time. The liquid is discharged from the liquid discharge port 17a. In the liquid sucked into the pressurizing passage 33, a vortex occurs between the inside of the blade groove 39 of the impeller 37 and the pressurizing passage 33, and the vortex flows in the pressurizing passage 33 while being simultaneously performed in each blade groove 39,
The pressure is increased as it proceeds through the pressure increasing passage 33.

When the liquid is sucked into the pressurizing passage 33 from the liquid suction port 12a, the gas is also sucked into the inlet portion 34 of the pressurizing passage 33 from the gas passage 26a of the suction nozzle 26, and the liquid and the gas are combined. The turbulence generated between the impeller 37 and the pressurizing passage 33 causes the air to be stirred, and fine bubbles are produced.

At this time, the flow rate of the liquid sucked into the pressurizing passage 33 is high and the pressure is low at the inlet portion 34 of the pressurizing passage 33. Therefore, the suction nozzle inserted into the inlet portion 34 of the pressurizing passage 33
26, the gas is efficiently introduced into the liquid from the gas through holes 26a, and the gas is introduced into the liquid from the gas through holes 26a by the suction nozzle 26, so that the gas into the liquid is Suction can be performed smoothly, and therefore, the gas suction amount is large.

The gas-liquid mixture pressurized by mixing the gas into the liquid by the upstream vortex pump 11a is supplied to the gas-liquid discharge port 17a.
From the whirlpool pump 11b on the downstream side through the pipe 31, and is similarly sucked into the impeller.
The pressure is increased while moving through the pressurizing passage 33 by the 37, and is discharged from the gas-liquid discharge port 17b to the surplus gas separation tank 19 through the pipe 18.

Next, the operation of the gas-liquid mixing and dissolving apparatus shown in FIG. 1 will be described.

A liquid such as clean water purified by the flotation tank 13 is sucked by the vortex pump 11a. At this time, while observing the suction pressure gauge 28, the suction pressure adjusting valve 15 is throttled, the liquid suction port 12a of the vortex pump 11a is set to a negative pressure, and the suction nozzle 26 is
More air and other gases are simultaneously sucked. At this time, the flow rate of the gas injected into the liquid is adjusted by the air flow meter 23, and the gas can be injected up to, for example, about 20 to 30% in gas-liquid ratio.

If the gas is simply sucked in, the pump discharge pressure and the liquid flow rate may greatly decrease and fluctuate depending on the suction amount. However, the discharge pressure and the liquid pressure of the preceding vortex pump 11a are affected by the suction force of the subsequent vortex pump 11b. The amount of reduction in the flow rate is greatly reduced, and a stable operation state with a small amount of reduction fluctuation is obtained.

The gas-liquid mixture agitated and mixed inside the former vortex pump 11a is sent to the latter vortex pump 11b. The agitation and mixing of gas and liquid are similarly performed inside the vortex pump 11b at the subsequent stage. This multi-stage treatment increases the stirring and mixing effect.

Further, the discharge pressure of the pump is increased by the throttle of the discharge pressure adjusting valve 22, and the gas is dissolved under pressure in the liquid. The pressure acting on each of the vortex pumps 11a and 11b shares the pump discharge pressure with the number of pumps.
Pressure dissolution is performed by the working pressure for each of a and 11b.

The undissolved surplus gas that has not been dissolved in the liquid is released to the atmosphere from the vent valve 27 of the surplus gas separation tank 19, and the completely dissolved pressurized liquid is discharged by the discharge pressure regulating valve 22. The gas that is rapidly depressurized to atmospheric pressure and dissolved in the liquid,
The bubbles are released as fine bubbles into the liquid in the flotation processing tank 13.

These fine bubbles adhere to the contaminants floating in the liquid, float and separate the contaminants, and purify the liquid. This cycle is performed continuously to purify liquid quality such as water quality.

FIG. 3 shows the two vortex pumps shown in FIG.
FIG. 8 is a graph of pump performance at the time of air injection measured in comparison between a case where 11a and 11b are connected in series and a case where the conventional single vortex pump 11 shown in FIG. 7 is used. For the measurement of this data, a vortex pump 20NPD made by Nikuni Co., Ltd.
07Z is used.

In FIG. 3, bold lines A and B show the liquid flow rate / pump discharge pressure characteristics when two vortex pumps 11a and 11b are connected in series, respectively. Flow rate when using the vortex pump 11
The pump discharge pressure characteristics are as follows: a thick line A and a thin line a indicate a case where the air injection amount is 2 N l / min, and a thick line B and a thin line b indicate a case where the air injection amount is 4 N l / min.

In the case of the present apparatus shown by the thick lines A and B, although the characteristics are deteriorated due to the increase of the air injection amount, it is possible to maintain a stable operation state in the entire range within the illustrated range.

On the other hand, in the conventional case shown by the thin lines a and b, the usable region is shown by the solid line portion where the liquid flow rate is large, and the dotted line portion where the liquid flow amount is small and a stable operation state cannot be obtained. There are some unusable areas.

Next, the effects of the embodiment shown in FIGS. 1 and 2 can be summarized as follows.

(1) In this apparatus, the amount of gas suction increases, and the amount of reduction in the pump discharge pressure and the amount of liquid supply caused by gas suction is small, and a stable operation state can be maintained.

A. The amount of gas suction increases. That is,
The gas-liquid ratio between the gas suction amount and the liquid sending amount is up to 13.8% in the conventional one-pump system, but it is up to 32.3% in the improved device. Can be. This is a whirlpool pump 20NPD made by Nikuni Co., Ltd.
It is comparative measurement data by 04Z.

B. The operating state during gas suction is stable. That is, even if the amount of gas suction is largely changed, the amount of change in the discharge pressure and the amount of liquid sent is small, and the operating state is stable. Inability to supply liquid, i.e., an idling state, caused by sudden and large fluctuations does not occur.

(2) Since the plurality of vortex pumps 11a and 11b are connected in series, the differential pressure per pump with respect to the set pressure can be equally divided by the number of pumps used and can be used at a low pressure. In addition, a high-pressure gas solution can be produced at a high pressure as a whole.

A. The differential pressure per pump of the vortex pumps 11a and 11b is equally divided, and the differential pressure per pump can be used at a low pressure. The side clearance of the impeller 37 can be increased. In a vortex pump for slurry liquid or the like, the wear of the pump body 32 and the impeller 37 is eliminated and the life is extended, so that the reliability is improved. During low-pressure operation of the pump, the amount of liquid leakage from the impeller side clearance inside the pump is small, and the pump can be used with high pump efficiency.

B. The pressure can be increased to be twice the number of vortex pumps 11a and 11b used. Since the amount of dissolved gas is proportional to the applied pressure according to Henry's law, a high-concentration gas-dissolved solution can be produced by dissolving gas-liquid under high pressure.

Thus, a plurality of vortex pumps 11a, 11
In the method using b connected in series, a large amount of gas can be mixed and dissolved by suctioning a large amount of gas into the liquid from the suction side of the first vortex pump 11a without using a compressor or the like, The pressure can be further increased by the second vortex pump 11b to enhance the effect of mixing and dissolving.

That is, since the plurality of vortex pumps 11a and 11b are connected in series, the differential pressure per one vortex pump with respect to the set pressure can be used at a low pressure equally divided by the number of pumps used. The pump discharge pressure can be increased to twice the number of pumps 11a and 11b used, thereby increasing the amount of gas suction and reducing the amount of pump discharge pressure and liquid supply caused by gas suction. The operating state is stable, and a high-concentration gas solution can be produced efficiently.

It should be noted that three or more vortex pumps may be connected in series. That is, at least one of the upstream vortex pump 11a having the suction nozzle 26 or the downstream vortex pump 11b having no suction nozzle 26 is preferably provided in a plurality and connected in series.

Next, FIG. 4 shows another embodiment of the gas-liquid mixing and dissolving apparatus. As shown in FIG. 4 (A), the liquid suction port 12 of the multi-stage vortex pump 11c is connected to the submerged liquid. A pipe 14 drawn out from the bottom of a flotation treatment tank 13 for flotation and separation of contaminants to purify the liquid is connected via a suction pressure regulating valve 15, and is a gas for sucking gas such as air. The suction means 16 is also connected to the liquid suction port 12 of the multi-stage vortex pump 11c.

Further, a pipe 18 is drawn out from a gas-liquid discharge port 17 for discharging a gas-liquid mixture in which gas is mixed and dissolved in the liquid by the multistage vortex pump 11c. A line 21 inserted into an excess gas separation tank 19 for separating excess gas in the mixture and drawn out from the bottom of the excess gas separation tank 19 passes through a discharge pressure regulating valve 22 to the flotation separation processing tank. It is inserted to the center in the bottom of 13.

The gas suction means 16 has a tip of a suction nozzle 26 equipped with a flow meter 23, a check valve 24 and a solenoid valve 25 which can be freely opened in the suction direction, and is connected to the liquid suction port 12 of the multistage vortex pump 11c. Has been inserted.

The surplus gas separation tank 19 is provided with a vent valve 27 such as an air vent valve at the upper part of the closed vessel, and this vent valve 27 gradually removes only surplus gas in the liquid to the outside. To be discharged. The gas-liquid mixture in the surplus gas separation tank 19 is in a pressurized state, and is injected into the bottom of the floating separation processing tank 13 through the pipe 21.

A suction pressure gauge (compound gauge) 28 is provided in the pipe 14 on the suction side of the multistage vortex pump 11c, and a discharge pressure gauge 29 is provided in the pipe 18 on the discharge side of the multistage vortex pump 11c. Have been.

As shown in FIG. 4B, the multi-stage vortex pump 11c has a plurality of stages of impellers 37a and 37b rotatably provided inside a single pump body 32.
These impellers 37a and 37b are rotatably supported by a pump body 32 via a bearing 42 by a common rotating shaft 41.

A plurality of boosting passages 33a, 33b are provided in a ring shape along the impellers 37a, 37b, respectively. The boost passages 33a, 33b have inlets 34a, 34b at one end thereof and outlets 35a, 35b at the other end thereof.
The outlet part 35a of a and the inlet part 34b of the downstream pressure passage 33b are connected in series by an internal passage 43. The liquid suction port 12 communicates with the inlet 34a of the upstream pressure passage 33a, and the gas-liquid discharge port 17 communicates with the outlet 35b of the downstream pressure passage 33b.

Next, the operation of the gas-liquid mixing and dissolving apparatus shown in FIG. 4 will be described.

The liquid such as clean water purified in the flotation tank 13 is sucked by the multistage vortex pump 11c. At this time, while observing the suction pressure gauge 28, the suction pressure adjusting valve 15 is throttled, the liquid suction port 12 of the multistage vortex pump 11c is set to a negative pressure, and gas such as air is simultaneously sucked from the suction nozzle 26.

The first stage impeller 37 of the multistage vortex pump 11c
In a, gas-liquid suction and agitation mixing are performed, and are sent to the second-stage impeller 37b. In the second stage impeller 37b, the gas-liquid agitation and mixing are similarly performed. By performing the stirring and mixing in multiple stages, the effect of stirring and mixing is increased.

Further, the discharge pressure of the pump is increased by the throttle of the discharge pressure regulating valve 22, and the gas is dissolved under pressure in the liquid. Since the pressure acting on each of the impellers 37a and 37b divides the pump discharge pressure equally by the number of the impellers, the pressure dissolution is performed for each impeller by the differential pressure.

The undissolved surplus gas that has not been dissolved in the liquid is released to the atmosphere through the vent valve 27 of the surplus gas separation tank 19, and the completely dissolved pressurized liquid is discharged by the discharge pressure regulating valve 22. The gas that is rapidly depressurized to atmospheric pressure and dissolved in the liquid,
The bubbles are released as fine bubbles into the liquid in the flotation processing tank 13.

As described above, the boosting passages 33a, 33b of a plurality of stages are provided.
-Stage vortex pump 11c having a pump and impellers 37a, 37b
In the first stage, a large amount of gas is suctioned at a negative pressure without using a compressor or the like to mix and dissolve the mixture under pressure.
In a plurality of stages after the first stage, the pressure is further increased, and the mixture is dissolved under pressure to produce a gas solution having a high concentration.

That is, since the pressure-raising passages 33a and 33b along the plurality of stages of the impellers 37a and 37b are connected in series by the internal passage 43, the differential pressure per impeller relative to the set pressure is The pump can be used at a low pressure equally divided by the number of used wheels 37a and 37b, and the pump discharge pressure can be increased to be twice the number of used blades 37a and 37b.

As a result, the amount of gas suction is increased, the amount of reduction in the pump discharge pressure and the amount of liquid supply caused by the gas suction is small, the operation state during gas suction is stable, and the high-concentration gas solution Can be manufactured efficiently. Furthermore, a plurality of stages of impellers 37a, 37
Since b was added, the device can be made compact and inexpensive.

Next, FIG. 5 shows a gas suction means 16a as a modified example in which the gas suction means 16 in the gas-liquid mixing and dissolving apparatus is simplified, and the upstream-side vortex pump 11a (or the multi-stage vortex pump 11c). ) Liquid inlet 12a (or 1
A vertically provided gas suction pipe 51 having an open upper end is connected to and communicates with the suction nozzle 26 inserted in 2).

The gas suction pipe 51 is located above the liquid surface 52 in the flotation / separation processing tank 13 as a tank connected to the liquid suction port 12a of the vortex pump 11a by the pipe line 14, that is, at a position higher than the liquid surface 52. And the upper end of the tube was opened.

The vortex pump 11a is connected to the gas suction pipe 51.
A gas such as air is sucked into the liquid suction port 12a through the suction nozzle 26 from the upper end opening of the nozzle. The suction amount of this gas is adjusted by the suction pressure adjusting valve 15 while watching the suction pressure gauge 28,
A moderate gas flow is sucked.

As described above, since the operation state at the time of gas suction is stable, fine adjustment of the gas injection amount is not required, that is, the air flow meter 2 used for operation adjustment of the gas suction amount.
3. A simple structure that does not require the check valve 24 and the solenoid valve 25, and raises the thin gas suction pipe 51 to a position higher than the liquid level 52 in the flotation tank 13 and leaves its tip open. Thus, the gas suction means 16a can be simplified, and the cost can be reduced.

Next, FIG. 6 shows a more simplified excess gas discharging means in place of an air release valve 27 such as an air release valve of an excess gas separation tank 19 for separating excess gas in the gas-liquid mixture. A modified example is shown, and as shown in FIG. 6 (A), a discharge pipe 63 for discharging gas is provided from the sealed upper part 61 of the surplus gas separation tank 19 to another tank 62. An open / close adjustable gas discharge valve 64 is provided in the discharge line 63 as a throttling means for imparting discharge resistance to the gas.

As shown in FIG. 1 or FIG. 4, the surplus gas separation tank 19 has a gas-liquid discharge port 17b for discharging a gas-liquid mixture provided in the vortex pump 11b (or the multistage vortex pump 11c). (Or 17) is connected to the conduit 18.

The squeezing means may be a simple orifice 65 whose opening and closing cannot be adjusted as shown in FIG. The other tank 62 is preferably the flotation processing tank 13 shown in FIG. 1 or FIG. 4, but is not limited thereto.

The surplus gas not dissolved in the liquid by the plurality of vortex pumps 11a, 11b or the multistage vortex pump 11c passes through a gas discharge valve 64 or an orifice 65 provided at the upper part of the surplus gas separation tank 19. Is discharged to the upper side of the tank 62 by the discharge line 63. At this time, even if not only the surplus gas but also the liquid flows out from the upper part of the surplus gas separation tank 19, the liquid passes through the gas discharge valve 64 or the orifice 65 and is discharged to the upper side of the tank 62 by the discharge pipe 63. Is stored in the tank 62.

As described above, not only the surplus gas in the surplus gas separation tank 19 but also a part of the liquid is passed through the gas discharge valve 64 or the orifice 65 merely as a throttling means, and then discharged through the discharge line 63. Collect at 62.

Therefore, as in the case of an air release valve having a float check valve structure which closes when the liquid level rises, the excess gas separation tank 19 is closed.
In the automatic valve structure for preventing the liquid from leaking from the inside, there is a possibility that the liquid may be clogged with impurities in the dirty liquid, while the gas discharge valve 64 or the orifice 65 merely as a throttle means.
Are excellent in that they are less likely to be clogged by foreign substances such as impurities in the liquid. Further, since an air vent valve is not required, the cost of parts can be reduced in manufacturing the apparatus.

The present gas-liquid mixing and dissolving apparatus mixes and dissolves various gases such as air, oxygen and ozone into a liquid. The present apparatus includes a fine bubble generating apparatus, an oxygen enriching apparatus and an ozone dissolving apparatus. included.

[0082]

According to the first aspect of the present invention, since a plurality of vortex pumps are connected in series, the differential pressure per one vortex pump with respect to the set pressure is a low pressure divided equally by the number of pumps used. And the pump discharge pressure can be increased to twice the number of vortex pumps used, thereby increasing the amount of gas suction and reducing the amount of reduction in pump discharge pressure and liquid supply caused by gas suction. Can improve the stability of the operating state at the time of gas suction, can efficiently and stably mix and dissolve a large amount of gas in liquid,
High-concentration gas solution can be produced in large quantities.

According to the second aspect of the present invention, since the respective boost passages along the plurality of stages of the impeller are connected in series,
The differential pressure per impeller with respect to the set pressure can be used at low pressure equally divided by the number of used impellers,
The pump discharge pressure can be increased by the number of times the number of impellers used, thereby increasing the amount of gas suction and reducing the amount of reduction in pump discharge pressure and liquid supply caused by gas suction. Can improve the stability of the operating state, can efficiently and stably mix and dissolve a large amount of gas in the liquid, and can produce a large amount of high-concentration gas-dissolved liquid. Furthermore, since a plurality of stages of impellers are provided in a common pump body, the device can be provided more compactly and at lower cost than when two vortex pumps are connected.

According to the third aspect of the present invention, since the operating state at the time of gas suction is stable, a conventional air flow meter or the like used for adjusting the amount of gas suction is not required. The gas suction means can be simplified by using only the gas suction pipe which is opened up from the liquid level in the tank connected to the port, and the cost can be reduced in manufacturing the apparatus.

According to the fourth aspect of the present invention, not only the surplus gas in the surplus gas separation tank but also the liquid can be discharged to another tank by a discharge pipe through a simple throttle means. Like an air vent valve with an open / close structure that prevents liquid from leaking from the inside, the risk of clogging by impurities in the liquid can be prevented, and maintainability can be improved.
Since an air vent valve is not required, the cost of parts can be reduced in manufacturing the device.

[Brief description of the drawings]

FIG. 1 is a fluid circuit diagram showing an embodiment of a gas-liquid mixing and dissolving apparatus according to the present invention.

FIG. 2 is a sectional view of a plurality of vortex pumps used in the gas-liquid mixing and dissolving apparatus.

FIG. 3 is a performance graph at the time of air injection comparing the plurality of vortex pumps with the conventional single vortex pump.

4A is a fluid circuit diagram showing another embodiment of the gas-liquid mixing and dissolving apparatus according to the present invention, and FIG. 4B is a sectional view of a vortex pump used in the gas-liquid mixing and dissolving apparatus. is there.

FIG. 5 is a fluid circuit diagram showing a modified example of the gas suction means in the gas-liquid mixing and dissolving apparatus.

FIG. 6A is a fluid circuit diagram showing a modified example of the surplus gas discharging means from the surplus gas separation tank in the gas-liquid mixing and dissolving apparatus, and FIG. 6B is a fluid circuit diagram of the throttling means in the surplus gas discharging pipe. It is explanatory drawing which shows another example.

FIG. 7 is a fluid circuit diagram showing a conventional gas-liquid mixing and dissolving apparatus.

[Explanation of symbols]

 11a, 11b Multiple swirl pumps 11c Swirl pump 12 Liquid inlet 12a Liquid inlet 13 Tank 16 Gas inlet 16a Gas inlet 17 Gas-liquid outlet 17b Gas-liquid outlet 19 Excess gas separation tank 32 Pump body 33a, 33b Multiple Step-up passage 37a, 37b Multi-stage impeller 51 Gas suction pipe 52 Liquid level 62 Tank 63 Discharge line 64 Gas discharge valve as throttle means 65 Orifice as throttle means

Claims (4)

[Claims] 1. A gas-liquid mixing and dissolving system comprising: a plurality of vortex pumps connected in series for sequentially feeding liquid; and gas suction means connected to a liquid suction port of an upstream vortex pump. apparatus. 2. A pump main body of a vortex pump, a plurality of stages of impellers rotatably provided inside the pump main body, and a plurality of stages provided along these impellers, each of which is connected in series. A gas-liquid mixing and dissolving apparatus comprising: a pressure increasing passage; and gas suction means connected to a liquid suction port in an upstream pressure increasing passage. 3. The gas suction means according to claim 1, wherein the gas suction means is formed by a gas suction pipe which is opened upward from a liquid level in a tank connected to the liquid suction port of the vortex pump. 3. The gas-liquid mixing and dissolving apparatus according to 2. 4. A surplus gas separation tank connected to a gas-liquid discharge port for discharging a gas-liquid mixture provided in the vortex pump, for separating surplus gas in the gas-liquid mixture, and the surplus gas separation tank is hermetically sealed. The gas-liquid mixing and dissolving apparatus according to any one of claims 1 to 3, further comprising: a discharge pipe disposed from the upper portion to another tank through a restricting means for giving a discharge resistance to the gas.