JP2792016B2 - Gas-liquid dissolving and mixing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas-liquid dissolving and mixing apparatus for reacting and dissolving various gases in a liquid under pressure.

[0002]

2. Description of the Related Art Conventionally, generally, as a method of reacting a gas and a liquid under pressure or dissolving a gas in the liquid, a liquid in which a gas is to be dissolved is once contained in a pressurized tank, and a large amount of the liquid is contained in the liquid. And a gas-liquid dissolving and mixing method in which a gas-liquid reaction and gas dissolution are performed in this pressurized tank.

[0003] The applicant of the present application has filed Japanese Patent Application No.
As shown in Japanese Patent No. 149880, a part of the flow path is narrowed by a venturi-shaped throttle provided in the liquid flow path, and the flow path is gradually widened downstream of the throttle. On the downstream side, a gas is suctioned from the gas inlet that has become a negative pressure to form a gas-liquid mixed flow, a nozzle is provided downstream of this flow path, and the pressure in the flow path on the upstream side of the nozzle is And a gas-liquid dissolving / mixing device for supplying a gas-liquid mixed flow in which the gas is dissolved through pressure to dissolve the gas under pressure inside the flow path on the upstream side of the nozzle portion through the nozzle portion. I have.

[0004]

In the case of using the above-mentioned conventional pressurized tank, the liquid in the pressurized tank must be in a stopped state, and the gas in the pressurized tank must be dissolved in the liquid contained in the tank. However, the gas cannot be continuously dissolved in the liquid. Therefore, in order to obtain a high gas-liquid contact state in the pressurized tank, a large amount of gas must be injected into the pressurized tank, which wastes gas and is inefficient. In particular, when an expensive gas is used, the cost increases. Furthermore, in order to dissolve the gas in the pressurized tank, the pressure between the liquid in the pressurized tank and the gas to be injected must be appropriately adjusted, and this adjustment depends on the temperature, pressure, liquid temperature, etc. Therefore, each time these parameters fluctuate, each pressure must be adjusted.

Further, in the case of the gas-liquid dissolving and mixing apparatus of the applicant of the present invention, a liquid is pumped by a pump in order to obtain a gas-liquid mixed flow, and the pressure of the liquid must be relatively increased. Instead, it required a lot of power. Therefore, energy efficiency is not good, and pumping devices such as pumps are limited.

The present invention has been made in view of the above-mentioned problems of the prior art, and provides a gas-liquid dissolving / mixing apparatus capable of continuously and efficiently dissolving and mixing a large amount of gas in a liquid with high efficiency. The purpose is to do.

[0007]

According to the present invention, there is provided a throttle unit such as a venturi tube or an orifice provided in a liquid flow path,
The gas inlet is open downstream of the throttle
The inner diameter is slightly larger than that of the constriction, and
A cylindrical gas inlet with the same cross-sectional area
The flow path is provided on the downstream side continuously and gradually widens the flow path
Section, a mixing section including a pipe or the like provided downstream of the expanding section and mixing the liquid in the flow path and the gas flowing from the gas inlet, and a valve provided on the outlet side of the mixing section. The gas-liquid dissolving and mixing apparatus has a fixed throttle or an outlet throttle such as a nozzle portion, and further includes a gas pressure feeding means such as a compressor or a cylinder connected to the gas inlet. The pressure of the gas introduced from the gas inlet by the gas pumping means is set higher than the static pressure of the flow path at the gas inlet and lower than the maximum static pressure of the mixing section.

[0008] The mixing section is formed in such a shape that its flow path repeats gradual increase and decrease. Further, a branch flow path protruding upward is provided on the upstream side of the outlet throttle, and an exhaust throttle for exhausting gas that has not been completely dissolved is provided downstream of the branch flow path. Also, a pressure sensor for detecting the pressure of at least one of the mixing section and the gas pumping means is provided, and an adjusting member such as a valve or a regulator for controlling a pumping gas pressure or a flow rate of the gas pumping means via a control device. Is provided.

[0009]

The gas-liquid dissolving / mixing apparatus according to the present invention has a gas inlet at a gas inlet just downstream of a throttle such as a throat of a venturi tube.
The gas is introduced into the liquid flow by
In the mixing section, which is located on the downstream side and where the flow slows down and the static pressure increases, the inflowing gas is pressurized and dissolved, and then the liquid in which the gas is dissolved is ejected from an outlet throttle such as a nozzle portion at the outlet. . Further, at this time, the gas dissolved under pressure precipitates as fine bubbles due to a decrease in the static pressure, and the gas that has not been completely dissolved is sheared by the outlet throttle to form fine bubbles in the liquid. Further, by exhausting the excess gas from the gas-liquid mixed flow, it is possible to bring only the gas dissolved under pressure into the liquid into a supersaturated state or a state in which the gas is precipitated as fine bubbles.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gas-liquid dissolving and mixing apparatus of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention. As shown in FIG. 1, a gas-liquid dissolving and mixing apparatus according to this embodiment includes air, oxygen, ozone, and other impurities in a liquid such as water. It has a mixer 10 for mixing various gases such as an active gas, and a front end of a liquid pipe 12 is attached to an inflow portion 11 of the mixer 10. Further, a pipe 14 is also connected to the outlet 13 of the mixer 10,
A nozzle portion 16 as an outlet restrictor is attached to the tip of the nozzle. The nozzle portion 16 is provided with a processing solution 21 in which gas is dissolved or bubbles are formed through a tubular mounting portion 18.
Is connected to and opened to the side wall of the processing liquid tank 20 containing the liquid. The processing liquid 21 is stored in the processing liquid tank 20 in advance and foamed by a gas-liquid mixed flow,
A gas-liquid mixed flow may be stored.

As shown in FIG. 2, a venturi-shaped flow path 24 having a throat portion 22 as a throttle portion provided at the center thereof is formed in the mixer 10. An expanding portion 26 is formed downstream of the venturi tubular flow channel 24, and a cylindrical gas having a slightly larger inner diameter than the throat portion 22 is formed in the flow channel 24 between the throat portion 22 and the expanding portion 26. Inflow section 27
The gas inlet 27 is provided with a gas inlet 28 for mixing a gas such as oxygen or air into the flow path 24. At the outer end of the gas inlet 28, FIG.
As shown in the figure, a gas inflow line 30 for pumping a predetermined gas
Is connected, and the gas inflow pipe 30 is connected to a compressor 32 which is a gas pressure feeding means.

The gas inlet 2 is located downstream of the expanding portion 26.
There is provided a mixing section 34 for mixing the gas flowing from 8 with the liquid in the flow path. The mixing section 34 includes the inside of the mixer 10 on the downstream side of the expanding section 26 and the inside of the conduit 14. The outer diameter of the mixing section 34 of the conduit 14 can be arbitrarily set in accordance with the degree of pressurization. Here, the mixing section 34 is formed in a cylindrical shape having an inner diameter slightly larger than the maximum diameter of the expanding section 26. . And, as shown in FIG. 3, a plurality of nozzle ports 36 are formed in the nozzle portion 16 provided at the distal end portion of the conduit 14 also serving as the mixing portion 34, and
8 is connected. The nozzle portion 16 serving as the outlet throttle may be a nozzle having a single nozzle port 36, a valve, or another throttle.

The operation of the gas-liquid dissolving and mixing apparatus of this embodiment will be described below. First, the mixer 1 is connected through the liquid line 12.
The liquid, such as water, flowing into the inflow portion 11 is accelerated in the throat portion 22 of the flow path 24, and once the static pressure is reduced, and the spread portion 2
Through 6, the flow velocity slows down and the static pressure increases again. At this time, the gas pumped by the compressor 32 is sent from the gas inlet 28 to the gas inlet 27 of the flow path 24. Here, the static pressure of the gas inlet 27 and the compressor 3
Pressure at the gas inlet 28 of the gas pumped by 2;
The maximum static pressure in the mixing section 34 must satisfy the following equation. Continuous _{P A <P G <P M} (1) where, P _G is the pressure P _M of the gas flowing from the gas inlet 28 the maximum static pressure P _A in the mixing section 34 and the Bernoulli's theorem on hydrodynamic The static pressure P _A at the gas inlet 27 given by the following equation: P _A = (1−S ² _B / S ² _A ) P ₁ + (δP + P _B ) S ² _B / S ² _A (2) , S _A is the cross-sectional area of the gas inlet 27, S _B is the total cross-sectional area of the nozzle port 36, P ₁ is the total pressure of the gas inlet 27, δ
P is the pressure loss from the gas inlet 27 to the nozzle port 36,
P _B is the static pressure at the outlet of the nozzle port 36.

The reason why the gas inlet 28 is not opened to the throat portion 22 of the flow passage 24 where the static pressure is minimum is as follows.
Although the throat portion 22 is the portion where the static pressure is the lowest, when the gas inlet 28 is opened in the throat portion 22, the inflow of gas is not good, and the gas inflows at a portion where the flow path has begun to slightly widen. Because it is easy. Further, the gas inflow section 27 is connected to the flow path 2.
The reason why the gas flow inlet 4 is formed in a cylindrical shape having a cross section equal to the flow direction is that the gas inflow is smoother and more efficient when the gas inlet 28 is formed in the cylindrical flow path 27.

Accordingly, by setting the pressure of the compressor 32, the size of the gas inlet 27 and the size of the nozzle port 36, etc. so as to satisfy the above equations (1) and (2), the gas can be efficiently introduced into the liquid. Optimum conditions for mixing and dissolving are obtained. Further, it is more preferable that the mixing section 34 be capable of obtaining a gas-liquid contact time until the gas dissolves in the liquid under pressure and becomes supersaturated. Since the gas-liquid contact time depends on the volume of the mixing section, the length of the mixing section 34 is preferably longer to some extent.

The gas flowing in from the gas inlet 28 flows into the mixing section 34 together with the liquid in the flow path 24 as bubbles.
The gas that has become bubbles dissolves in the liquid because the static pressure of the mixing section 34 is higher than that of the throat section 22. And the mixing unit 34
After that, the static pressure decreases again through the nozzle port 36, and the dissolved gas becomes fine bubbles and precipitates in the liquid. In addition, the gas is dissolved in the liquid in a supersaturated state, and the static pressure in the mounting portion 18 and the processing liquid tank 20 is relatively lower than that in the mixing portion 34. Large amounts of microbubbles precipitate in the liquid. Further, the gas that has not been completely dissolved is finely sheared at the nozzle port 36, and is sprayed into the processing liquid 21 as fine bubbles of several tens to several hundreds μm.

According to the gas-liquid dissolving and mixing apparatus of this embodiment,
Since the gas is pressure-fed by the compressor and fed into the flow path 24, the flow of the gas is smooth and the pressure-feeding energy of the liquid can be reduced. Experimentally, the power for sending the gas-liquid mixed flow in the mixing unit 34 is 60 in the case of the present embodiment, compared with the case where the same gas-liquid mixed flow is sent only by suction without pumping the gas. % Was obtained. This is because most of the power of this device is used for pumping the liquid. In the present embodiment, the pump for pumping the liquid is set to a little less than 60% of the conventional power, and the pump for pumping the liquid is used. This is due to the fact that the compressor 32 for gas pressure feeding, which operates with much smaller power as compared with the above, is attached. This allows
Even if the pressure of the liquid is small, the gas-liquid mixed flow easily flows due to the gas being pumped, and the same flow rate of the gas-liquid mixed flow as in the case where the gas is not pumped is obtained.

Next , another embodiment of the mixer will be described with reference to FIG. Here, the same members as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the mixer 40 of this embodiment, the gas inflow portion 47 is formed on a part of the slope on the upstream side of the expanding portion 26. Therefore, the gas inflow portion 47 is formed in the widening portion 26 slightly downstream of the throat portion 22. A gas inlet 28 for mixing the gas into the flow path 24 is opened in the gas inflow portion 47 on the slope portion, and the gas is sent by the compressor 32. According to the gas-liquid dissolving and mixing apparatus of this embodiment, the gas can be efficiently mixed in the liquid, and the gas-liquid dissolving mixed liquid can be continuously formed with high efficiency with little power as a whole.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. Here, the same members as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIG. 6, the gas-liquid mixing / mixing apparatus of this embodiment has a gas-liquid mixing tank 50 in which a flow path 52 in which a liquid flows stepwise from top to bottom is formed, as shown in FIG. Pipe 14
Is provided on the way. And the inlet 5 of the flow path 52
The mixer 10 is provided on the upstream side of the nozzle 3 via an inflow line 54, and a nozzle portion 16 is provided on an outflow line 56 on the downstream side of the outlet 55.
Is provided.

The flow path 52 of the gas-liquid mixing tank 50 of this embodiment
Is formed in such a manner that the liquid gradually flows from top to bottom while repeating the steepness and steepness. By flowing a gas-liquid mixed flow through the flow path 52, the gas and the lower The liquid is then allowed to flow, and a flow having a large gas-liquid contact area can be obtained. Then, a nozzle portion 1 as an outlet throttle is provided in an outflow pipe 56 on the outlet 55 side of the flow path 52 in which the liquid flows down from top to bottom in a stepwise manner while repeating the acceleration and deceleration.
By providing 6, the static pressure inside the flow path 52 is increased, and the gas dissolving efficiency is increased. In addition, since the position of the outlet conduit 56 at the outlet is lower than the inlet of the inlet conduit 54 for the gas-liquid mixed flow, the gas-liquid mixed flow is stagnated in the flow passage 52, Since the larger liquid is easier to outflow than the gas, the gas stagnates more in the flow path 52 than the liquid, and even if the ratio of the gas is relatively low at the stage of the inflow pipe 54, the flow path In 52, the ratio of gas becomes high. Therefore, the gas-liquid mixing tank 5
0, highly efficient gas-liquid dissolution mixing is performed.

Next, a third embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. Here, the same members as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted. The gas-liquid dissolving and mixing apparatus according to this embodiment includes a pipe 1 upstream of the nozzle 16.
In the middle of 4, there is provided a branch member 60 having a branch flow path 61 in which the flow path branches in a T-shape. Branch member 60
As shown in the figure, a branch passage 61 is attached upward, and an exhaust pipe 64 is attached downstream of the branch passage 61 via a valve 62 that is an exhaust throttle.

In the gas-liquid dissolving / mixing apparatus of this embodiment, the surplus gas of the gas-liquid mixed flow flows into the information branch flow channel 61 at the branch member 60 and flows out to the exhaust pipe 64 via the valve 62. It is like that. Here, the valve 62 is capable of adjusting the pressure of the pressurizing section 34 in the pipeline 14, and also functions as a restrictor for maintaining the inside of the pressurizing section 34 at a desired pressure together with the exhaust of the excess gas. doing. By providing the branch member 60 for exhausting the surplus gas, only microbubbles of several μm to several tens μm can be formed in the processing liquid 21.

Next, a fourth embodiment of the present invention will be described with reference to FIG. Here, the same members as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted. The gas-liquid dissolving and mixing apparatus of this embodiment is provided with a pressure sensor 70 for detecting the pressure of the flow path 52 of the gas-liquid mixing tank 50 of the fourth embodiment, and outputs the pressure sensor 70 to the control device 72. Is what you are doing. The control device 72 is connected to a flow control valve 74 which is a pressure adjusting member provided in the gas inflow pipe 30 in accordance with the output of the pressure sensor 70.

In the gas-liquid dissolving and mixing apparatus of this embodiment, the compressor 32 is operated at a constant output, the pressure in the gas-liquid mixing tank 50 is detected, and the flow control valve 7 of the gas inflow line 30 is detected.
4 controls the above (1), in which can set an optimum gas pressure P _G that satisfies the equation (2). Thus, the gas-liquid mixed flow can be formed under the most efficient gas pressure feeding conditions, and the device can be made more energy efficient. Here, the gas pressure may be controlled by controlling the compressor 32 itself. In the case where a cylinder is used as the gas pumping means instead of the compressor 32, a regulator for adjusting the gas pumping pressure may be controlled by the output of the control device 72. Further, the pressure sensor 70 of this embodiment may be attached to the mixing section 34 of the first embodiment to control the pressure gas supply in the same manner.

Further, since the pressure in the gas-liquid mixing tank 50 is maintained at a substantially constant value by the liquid supply pressure of the liquid and the nozzle portion 16 which is an outlet restrictor, the pressure of the gas to be supplied is detected, it may be a desired gas pressure gas pressure P _G at the inlet 28. That is, as shown by a two-dot chain line in FIG. 9, instead of the pressure sensor 70, a pressure sensor 76 is attached to an accumulator provided between the compressor 32 and the flow control valve 74, and the output of the pressure sensor 76 is controlled by a control device. 72, and the flow control valve 74 may be adjusted as described above. Further, by attaching both of the pressure sensors 70 and 76, the pressure of the gas to be pumped is controlled even when the nozzle portion 16 is clogged or slight pressure fluctuation in the gas-liquid mixing tank 50 due to other causes. It is also possible to maintain the pressure in the gas-liquid mixing / feeding 50 at an optimal pressure state for the gas-liquid dissolution mixing.

In the gas-liquid dissolving / mixing apparatus of the present invention, a cylinder or a tank storing gas may be used as the gas pumping means, in addition to the compressor, or another gas pumping source may be connected. Further, the gas pumping condition may be any condition that satisfies the above formulas (1) and (2), and can be appropriately set.

[0027]

The gas-liquid dissolving and mixing apparatus according to the present invention converts gas into
Since the liquid is caused to flow into the liquid flow path by the pumping means , the gas can be continuously mixed and dissolved in the liquid with a simple device and with relatively small power as a whole with good energy efficiency. In addition, to pump gas
Can be lowered more pumping pressure of the liquid, it is out also the wider ones choice such as a pump for pumping the liquid.
Further, the condition of the above formula (1) is relatively wide, and gas-liquid melting and mixing can be performed with sufficiently high efficiency even when the conditions such as the air temperature and the liquid temperature slightly change. Further, by controlling the pressure of the gas to be pumped, a more efficient gas-liquid mixed state can be formed.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a first embodiment of a gas-liquid dissolving and mixing apparatus according to the present invention.

FIG. 2 is a vertical sectional view of a mixer of the gas-liquid dissolving and mixing apparatus of the first embodiment.

FIG. 3 is a longitudinal sectional view of a nozzle portion of the gas-liquid dissolving and mixing apparatus according to the first embodiment.

FIG. 4 is a longitudinal sectional view of another embodiment of the mixer .

FIG. 5 is a schematic view of a gas-liquid dissolving and mixing apparatus according to a second embodiment of the present invention.

FIG. 6 is a schematic longitudinal sectional view showing a gas-liquid mixing tank of the gas-liquid dissolving and mixing apparatus of the second embodiment .

FIG. 7 is a schematic view showing a gas-liquid dissolving and mixing apparatus according to a third embodiment of the present invention.

FIG. 8 is a longitudinal sectional view of a branch member of the gas-liquid dissolving and mixing apparatus according to the third embodiment .

FIG. 9 is a schematic view showing a gas-liquid dissolving and mixing apparatus according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Mixer 14 Pipe line 16 Nozzle part (exit throttle) 22 Throat part 24 Flow path 26 Expanding part 27 Gas inflow part 28 Gas inflow part 32 Compressor (gas inflow means) 34 Mixing part

──────────────────────────────────────────────────続 き Continuation of the front page (72) Masakazu Kashiwa, Izumi Electric Co., Ltd. 1-10-40, Mikuni Honcho, Yodogawa-ku, Osaka-shi, Osaka (56) References JP-A-6-63371 (JP, A) Patent 2670492 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) B01F 1/00 B01F 3/04 B01F 5/04

Claims (4)

(57) [Claims] A throttle provided in a liquid flow path ;
The gas inlet is provided on the downstream side following the throttle and opens
Slightly larger inside diameter than the constriction section and cross-section in the above flow direction
A cylindrical gas inflow section with the same product and a continuous
A divergent section that is provided downstream and gradually widens the flow path
When a mixing unit to form a the liquid and gas flowing from the gas inlet of the provided flow path downstream pressurized圧混combined gas-liquid mixed flow of the expanded portion provided on the outlet side of the mixing portion The outlet throttle, comprising a gas pumping means connected to the gas inlet and for pumping gas to a gas inlet, the pressure of the gas flowing from the gas inlet by the gas pumping means,
Greater than the static pressure of the flow path at this gas inlet,
A gas-liquid dissolving and mixing device set lower than the maximum static pressure of the mixing section. A throttle provided in the liquid flow path ;
The gas inlet is provided on the downstream side following the throttle and opens
Slightly larger inside diameter than the constriction section and cross-section in the above flow direction
A cylindrical gas inflow section with the same product and a continuous
A divergent section that is provided downstream and gradually widens the flow path
When a mixing unit for forming the expanded portion of the liquid and gas flowing from the gas inlet of the provided flow path downstream pressurized圧混combined gas-liquid mixed flow of, provided at the outlet side of the mixing portion Outlet throttle, a gas pumping means connected to the gas inflow port, a pressure sensor for detecting the pressure of at least one of the mixing unit and the gas pumping means, and an output of the pressure sensor for the gas pumping means. a controller for controlling the pumping gas pressure, and an adjustment member for adjusting the pressure of the gas fed to the gas inlet from the gas pumping means by the control device, the flow from the gas inlet by the gas pumping means
A gas-liquid dissolving and mixing apparatus wherein the pressure of the gas to be introduced is set higher than the static pressure of the flow path at the gas inlet and lower than the maximum static pressure of the mixing section. Wherein said mixing unit, the flow path is the gas-liquid dissolving and mixing apparatus according to claim 1 or 2, wherein is formed into a shape repeating stepwise pace. 4. A branch flow path protruding upward is provided upstream of the outlet throttle, and an exhaust throttle is provided downstream of the branch flow path for exhausting gas that has not been completely dissolved. 4. The gas-liquid dissolving and mixing device according to 2 or 3 .