JPS63158121A - Method and device for solution and transport of gaseous substance - Google Patents

Abstract

PURPOSE:To increase the solubility efficiency of gas into liquid by allowing an injector to absorb a gas with an absorptive force which corresponds to the kinetic energy of a fluid passing through the injector, and adding a liquid to the fluid. CONSTITUTION:A liquid ejected from a pump 2 flows into a cyclone 3, and is stirred violently under pressure in a rotary motion inside the cyclone 3. Further, the gas dissolves into the liquid, undergoing the process of stirring and conversion. In the cyclone 3, a liquid containing a large quantity of undissolved bubble gas is concentrated increasingly to the center of the cyclone 3 by means of centrifugal force. In addition, even the gas which does not dissolve easily is concentrated to the center after such association and subsequent volume increase. On the other hand, the liquid in which a gas dissolves moves to the lower part 3b of the cyclone 3, rotating and passes through an outflow port 15. After this the liquid is transported to an external destination via a valve V2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for continuously dissolving gas in a liquid (solvent) and transferring the gas in an atmosphere with a pressure higher than atmospheric pressure. The present invention relates to an apparatus useful for use in the method.

[Prior Art] As methods and devices for dissolving gas in liquid under pressure, that is, under pressure equal to or higher than atmospheric pressure, the following (a) to (C) are known.

(a) Equipment consisting of pumps, compressors, pressure tanks, etc. This device uses a compressor in a pressure vessel containing a liquid to feed gas, causes the liquid and gas to stay in the pressure vessel, and dissolves the gas from the liquid surface in an almost static state.

(b) A device in which a stirrer is attached to the pressure tank of (a) above to promote dissolution of gas.

(C.) A device in which a filler such as a baffle plate is provided in the pressure tank of (a) or (b) above.

[Problems to be Solved by the Invention] According to the melting device (a), the contact area of gas and liquid in the pressure tank is very small, and the melting is performed in a static state. For this reason, the gas-liquid dissolution efficiency is low,
There was a problem in that unless the pressure tank was made considerably large, the time required for melting would be long. In addition, the above (b)
If a stirrer is installed in the pressure tank, as in the dissolving device described above, dissolution will be somewhat accelerated, but the gas will still be dissolved only at the liquid level. Furthermore, a new power source must be provided to drive the agitator, and a seal structure must be provided between the pressure tank and the agitator. Theoretically, it would be possible to disperse the gas into the liquid in the tank by applying a strong stirring force using a special rotating blade, but it would be possible to disperse the gas into the liquid in the tank, but it would be possible to disperse the gas into the liquid while leaving the undissolved gas behind. In order to extract the water out of the tank, an additional tank must be provided, which is not practical. Further, according to the melting device (c), the melting efficiency is slightly improved compared to the devices (a) or (b), but the above-mentioned problems are not solved.

Furthermore, in order to statically dissolve gas using the conventional devices as described in (a) to (C) above, it is necessary to control the level of the liquid in the pressure tank. Therefore, it is necessary to provide equipment such as a means to adjust the amount of gas introduced into the pressure tank and a gas vent valve to separate undissolved gas in the pressure tank, making the entire device complicated and expensive. There was a problem with this.

[Purpose of the Invention] The inventor of the present application has discovered that in order to efficiently dissolve gas in liquid, it is generally necessary to lengthen the contact time of gas and liquid and increase the chance of contact between gas and liquid. I came to the conclusion that it would be sufficient to make the gas present in excess in the liquid and provide stirring. That is, according to the conventional apparatus and method described above, it was considered that an excessive amount of finely divided gas was present in the pressure tank and it was not possible to stir it.

Therefore, the inventor of the present application has developed a method for dissolving and transferring gas that can efficiently dissolve gas in liquid by increasing the contact time and chance of contact between gas and liquid by stirring the liquid with excessive presence of fine air bubbles. The purpose of this invention was to provide a device useful for this method.

[Means for Solving the Problems] In order to achieve the above-mentioned object and solve the conventional problems, the gas dissolution and transfer method according to the present invention comprises: pumping gas and liquid to a cyclone; The gas is dispersed and dissolved in the liquid by stirring and staying inside the cyclone, and at the same time, the gas and liquid are separated by centrifugal force.The dissolved liquid is extracted to the outside from the underflow port of the cyclone, and the liquid containing excess dispersed gas is removed. The fluid is extracted from the overflow port of the cyclone and passed through an injector, and the injector sucks gas with a suction force corresponding to the kinetic energy of the fluid passing through the injector, and further liquid is added to this fluid.
It is characterized in that the cyclone is used to force-feed again. Further, the gas dissolution and transfer device according to the present invention includes:
A pump that pumps gas and liquid, and the gas and liquid supplied from the pump are internally stirred and retained to disperse and dissolve the gas in the liquid, and the gas and liquid are separated by centrifugal force so that the dissolved liquid is under water. A cyclone extracted from a flow port, an injector through which a liquid containing excess dispersed gas extracted from the cyclone passes, and which sucks the gas into the interior with a suction force corresponding to the kinetic energy of the fluid passing through, and the injector. The pump is characterized by comprising a liquid inlet connected to an inlet of the pump as well as an outlet of the pump.

[Function] When gas and liquid are sucked into the pump, the gas is finely pulverized inside the pump, dispersed in the liquid, and a portion is dissolved in the liquid. The fluid discharged from the pump flows into the cyclone, and the fluid is stirred by rotational movement within the cyclone, and the gas is further dissolved into the liquid by stirring and retention. Within the cyclone, the liquid containing more undissolved gas collects in the center of the cyclone due to centrifugal force, while the liquid containing dissolved gas is drawn out from the liquid outlet. The liquid containing undissolved gas is then extracted from the cyclone, supplied to the injector, and passes through the injector toward the outlet. At this time, a suitable amount of gas is sucked into the injector by a suction force depending on the kinetic energy of the fluid passing through the injector, and the gas is dispersed in the fluid. The fluid that has passed through the injector joins the liquid supplied from the injector, enters the suction port of the pump, is compressed again, and is sent to the cyclone. That is, a liquid containing undissolved gas is circulated between the cyclone injector and the pump, and the injector self-controls the intake air amount according to the proportion of bubbles contained in this liquid. Therefore, according to the present invention, there are many opportunities for gas-liquid contact and the contact area is large, so that gas can be efficiently dissolved in a short time.

[Example 1 An embodiment of the present invention will be described with reference to FIGS. 1 to 6.

FIG. 1 is a schematic diagram showing a gas dissolving and transferring device 1 according to the present embodiment, and 2 in the figure is a device for dispersing and dissolving gas in a liquid and pumping the fluid to a cyclone 3 to be described later. It's a pump. Generally 1. In a normal centrifugal pump,
If the proportion of gas in the inflowing fluid becomes large, it may cause vibrations, abnormal noises, abnormal wear of the rotating blades, etc., as well as inconveniences such as the inability to discharge the fluid or the discharge becoming intermittent. There are cases. The inventors of the present invention believe that the cause of such inconvenience lies in the shape of the fluid passage in the impeller section, and further confirmed that the cause is that the cross-sectional area of the fluid passage is larger on the outlet side than on the inlet side. Therefore, the pump 2 used in this embodiment has a structure in which the impeller section can pump a large amount of gas together with liquid, as will be described later. Reference numeral 4 shown in FIG. 2(a) is an impeller body composed of a base 6 having a boss 6a to which a drive shaft 5 is attached, and a plurality of blades 7 provided on one side of the base 6. be. A disk-shaped side plate 8 having a hole 8a formed in the center is fixed to the blade 7 of the impeller main body 4, and constitutes an impeller portion 9. As shown in FIG. 2(a), the feeding blades 7 have a claw-shaped cross-sectional shape curved into an arc, and are formed by each blade 7, the side surface of the soil plate 6, and the inner surface of the side plate 8. A fluid passage 10 is configured. Unlike the fluid passage in a normal centrifugal pump, this fluid passage 10, as shown in FIG. 2(b),
The cross-sectional area on the oval-shaped population 11 side is large, and the cross-sectional area on the oval-shaped outlet 12 side is smaller, and its wall surface has a smooth shape without corners. However, depending on the manufacturing cost and other considerations, the cross-sectional shape of the fluid passage 10 may have corners such as a rectangular shape. Further, both cross-sectional areas are determined by the fluid pressure at the outlet 12 so that the apparent flow velocity of the fluid in the fluid passage 10 (the apparent flow rate of the fluid flowing within a certain period of time is the value obtained by dividing the volume by that time). Set according to the mixing ratio of air and liquid to be pumped. For example, water 6rn'/h.

When trying to mix and transfer air 2rn”/h, outlet 1
If the pressure of the fluid at 2 is 5 Kgf/c♂, the volume of the gas will be compressed to about 175, so the cross section MA on the inlet 11 side will be
And the cross-sectional area A' on the outlet 12 side can be determined by the following equation.

Next, the discharge port 13 of the pump 2 is connected and communicated with the cyclone 3. The cyclone 3 is a fluid tank for stirring and retaining the fluid supplied from the pump 2 under pressure to dissolve gas in the liquid. As shown in FIG. 3, this cyclone 3 has a cylindrical upper part 3a and a substantially conical lower half part 3b, and experimentally the cone angle of the lower half part 3b is 20 degrees. You will get good results if you do it before or after. The pipe P1 led from the discharge port 13 of the pump 2 is tangentially connected to the side surface of the upper half 3a via the valve v1 and the pressure gauge 01, but the cross-sectional shape of the connection part is , a rectangular shape elongated along the circumferential direction of the cyclone 3 is preferable. Further, a circulating fluid outlet 14 as an overfluorocarbon is provided in the center of the upper half 3a, and a pipe P2 is connected thereto. When the cyclone 3 is placed vertically as in this embodiment, it is preferable that the pipe P2 connected to the circulating fluid outlet (overfluoro) 14 not protrude into the inside of the cyclone 3. At the lower end of the cyclone 3, a solution outlet 15 for dissolving solution is provided as an under 70 port.

A pipe P3 is connected and communicated with this liquid outlet (underfluoro) 15, and the pipe P3 is provided with a pipe v2. Further, this cyclone 3 is provided with a pressure gauge 02.

The cyclone 3 of this embodiment is installed vertically, but when a cyclone 3' having approximately the same shape as this is installed horizontally, as shown in FIGS. 4(a) and 4(b), the circulating fluid outlet It is preferable to provide a gently sloped cone 16 between the (overfluoro) 14 and the pipe P2. Further, if it is desired to downsize the entire device or to keep manufacturing costs low, a cylindrical cyclone 17 as shown in FIGS. 5(a) and 5(b) may be used. Such a cylindrical cyclone 17 is similar to the cyclone 3.
．． Since the centrifugal force applied to the fluid is smaller than that of 3', the fluid separation performance is slightly inferior, but it is effective when handling gases that are difficult to dissolve.

Next, a pipe P2 connected to the circulating fluid outlet (overfluoro) 14 of the cyclone 3 is connected to the inlet 19 of the injector 18 via a flow needle G3 and a valve V3. As shown in FIG. 6, the injector 18 is a pipe-shaped device with a passage in the center through which fluid passes, and the inner diameter is narrowed from the inlet 19 to the center where the throttle hole 21 is located. It is formed into a tapered shape whose inner diameter increases from the central part to the outlet 20. A suction port 22 communicating with the throttle hole 21 is formed on the outer peripheral surface of the central portion, and an inflow port 1
Gas is sucked in from the suction port 22 by the kinetic energy of the fluid passing from the outlet 9 toward the outlet 20 . A check valve 23 is provided inside the suction port 22 to prevent fluid flowing from the inlet 19 toward the outlet 20 from being discharged from the suction port 22 to the outside. In addition, a disk-shaped twisted blade 24 is rotatably provided at the inlet 19 of the injector 18 to stabilize the gas suction force and to effectively atomize the gas sucked into the injector 18. It has become. Note that instead of such a disk-shaped twisting blade 24, a propeller-shaped blade with less pressure loss may be provided.

Next, a pipe P4 is connected to the suction port 22 of the injector 1B. A valve v4 and a flow meter 64 are connected to the pipe P4, and the gas inlet 28 is open to gas at a predetermined pressure.

Also, a pipe P5 connected to the outlet 20 of the injector 18
is inserted into the T-pipe 26 connected to the suction port 25 of the pump 2 from one open end thereof. Also T tube 2
A pipe P6 is connected to the other open end of the pipe P6 via a valve v5, and the end of the pipe P6 serves as a fluid inlet 27.

Next, a method for dissolving and transferring gas using the apparatus configured as described above will be described.

The pump 2 is driven by a drive means (not shown), and liquid and gas are supplied to the pump 2. The liquid and gas sucked into the impeller 11s9 are pressurized while moving through the smooth fluid passage 10. The fluid passage 10 of the impeller part 9 in the pump 2 of this embodiment has a large cross-sectional area on the inlet 11 side through which the uncompressed fluid passes, and a small cross-sectional area on the outlet 12 side through which the compressed fluid passes. It is. Therefore,
When a liquid and a gas, which is a compressible fluid, are pumped together, the apparent flow rate of the fluid from the inlet 11 to the outlet 12 in the fluid passage 10 is the apparent flow velocity (the apparent flow rate of the fluid flowing within a certain period of time is the volume calculated by subtracting the volume by that time). Since the pressure (value) remains constant, no regions with different pressures will occur in the fluid passage 10, and no problems such as harmful vortices will occur in the fluid passage 10.

In particular, in this embodiment, the wall surface of the fluid passage 10 has a smooth shape with no corners, so the resistance between the wall surface and the fluid is uniform in all parts, which may cause the wall surface to wear out. There is also no fear that fluid vortices will occur in specific parts. In this way, the gas and liquid sucked into the impeller part 9 have a smooth fluid passage! Since the pump 2 is smoothly transferred at a constant flow rate without creating vortices, even when a considerable amount of gas is pumped together with liquid, problems such as abnormal noise and vibration will not occur during operation of the pump 2. Moreover, the wall surface of the fluid passage 10 does not wear abnormally. Then, in the impeller section 9, the sucked gas is pressurized and pulverized into fine pieces, dispersed and mixed in the liquid, and a part of the gas is dissolved in the liquid.

The fluid protruding from the pump 2 flows into the cyclone '3,
This fluid is stirred in the cyclone 3 while rotating violently under pressure, and the gas is further dissolved in the liquid by stirring and retention.In the cyclone 3, the liquid containing more undissolved bubble-like gas is Due to centrifugal force, most of the particles gather in the center of cyclone 3. Also, gases that have become dissolved due to their association and increase in volume also gather in the center. On the other hand, the liquid containing dissolved gas (dissolved liquid) moves to the lower half 3b of the cyclone 3 while rotating, and the liquid exit (
15 and is transferred to an external destination (not shown) via valve V2. In this case, the amount of dissolved liquid coming out of the liquid outlet (underfluoro) 15 is kept constant by appropriately adjusting the opening degree of valve 2, etc., so the pressure in the system of this apparatus including cyclone 3 is is kept constant.

The liquid containing undissolved gas is extracted from the circulating fluid outlet (over 70 ports) 14, supplied to the inlet 19 of the injector 18, and passed through the injector 18 to the outlet 20.
passing towards. At this time, the kinetic energy of the passing fluid causes the suction port 22 to open inside the injector 18.
Gas is sucked from. The suction force of gas depends on the kinetic energy of the passing fluid, that is, the amount of gas contained in the fluid. For example, when the fluid extracted from the circulating fluid extraction port (overfluoro) 14 contains a large amount of gas, the kinetic energy of the fluid is small, so the amount of fluid sucked into the injector 18 is small.

Conversely, if the fluid contains almost no air, a large amount of gas will be sucked into the insector 18 due to the strong suction force corresponding to its kinetic energy. In this way, in the device 1 of this embodiment, the amount of gas suction is self-controlled. Then, the gas sucked in by the injector 18 is transferred to the cyclone 3
Together with the undissolved gas sent together with the liquid from the insector 18, the particles are atomized and dispersed and mixed into the liquid. In addition, in this embodiment, the injector 18 has twist blades 2.
4, the gas suction state is stable.

Next, Injecta! The fluid that has passed through the pipe P5 is sent into the T pipe 26 through the pipe P5. A predetermined amount of liquid is supplied into this T-tube 26 from an inlet 27 . The fluid and the liquid newly supplied into the system join together in this T pipe 26 and are sent to the suction port 25 of the pump 2.

As described above, in this embodiment, the pressure within the apparatus system is kept constant by supplying an appropriate amount of liquid into the system and extracting an appropriate amount of the dissolving liquid from the cyclone 3. The injector 18 self-controls the intake air amount while circulating a portion of the fluid including undissolved fluid within the system, thereby efficiently dissolving the gas into the liquid. In other words, the device of this embodiment! Because the fluid is circulated, there are many chances for gas and liquid to come into contact with each other, and because the gas is repeatedly atomized at various locations, the contact area between gas and liquid is large, so it is possible to statically extract gas only from the liquid surface. Gases can be dissolved more efficiently than conventional devices and methods that require dissolution.

The gas dissolving and transferring device 1 according to this embodiment has a simple structure, so the manufacturing cost can be reduced, and the pump 2 uses an impeller part 9 that is less prone to problems such as abnormal wear. Maintenance is also easy. Therefore, the device 1 can be effectively used in various fields, and can be used not only for dissolving gas in liquid but also for other purposes. That is, according to the device 1, part of the gas is dissolved in the liquid, and the remaining part is mixed into the liquid as fine dispersed bubbles. Therefore, if the amount of circulating fluid flowing into the injector 18, the amount of gas sucked in by the injector 18, and the amount of dissolving liquid discharged from the cyclone 3 are adjusted by valve operation etc., the gas dissolved in the liquid and the liquid The amount and ratio of dispersed air bubbles to be mixed inside can be set arbitrarily. Gas dissolved in a liquid precipitates as bubbles under atmospheric pressure, so if this device 1 is used in a wastewater flotation separation facility that utilizes such precipitated bubbles and the above-mentioned dispersed bubbles, it can be This is advantageous because the ratio and amount of dispersed bubbles and precipitated bubbles can be adjusted as desired.

Next, the results of testing the dissolving and transferring device 1 will be explained using a specific example. 3.7 Attach the impeller part 9 having the fluid passage 10 as described above to a normal centrifugal pump of lx 2900 rpm. Cyclone 3 has an inner diameter of 2
60 sus, content M191 is used. The injector 18 used had an inner diameter of about 10 m1 at the entrance/exit part, a total length of about 50 cm, and an inner diameter of the throttle hole 21 of about 3+s. The self-suction air amount of the injector 18 is calculated as follows: The inflow pressure of the injector 18 is 4, and the inflow amount is I
J! It has been experimentally confirmed that 1 ONf/sin is obtained when the current is /min.

Now, select air as the gas and water as the liquid,
The gas inlet 28 was opened to the atmosphere, and the liquid inlet 27 was connected to a water tank (not shown), and the apparatus was operated under various conditions. As a result, the liquid (water) inflow amount is 100 j27si
n, air suction amount average 2.54! /sin, cyclone internal pressure 4.5 kgf/crn", dissolved liquid withdrawal amount 100-
j! /sin, when the amount of circulating fluid was only water, 10 JL, the following results were obtained. That is, when the obtained solution is left under atmospheric pressure, the amount of air precipitated is 2.
5%, and even if the operation was carried out all day and night without adjusting the valves in this state, no change was observed in the amount of dissolved liquid and the amount of air precipitated from the same flow. However, the amount of air suction always fluctuated within the range of D to 10 L/inch from the indicated value of the flow meter 64.

From the above results, this device automatically controls air self-priming, and the amount of precipitated air is 2 with a residence time of 11.4 seconds.
．． It was confirmed that a 5% solution was obtained continuously.

In order to compare with the example of the test results described above, an example of operation will be shown in which a dissolving apparatus as shown in FIG. 7 is constructed and air is dissolved in water. In this device system, the cyclone 3 is replaced with a pressure tank 30 (capacity 2401), and the discharge port 13 of the pump 2 and the inlet port 19 of the injector 1B are connected and communicated with the lower part of the pressure tank 30. Further, a solution extraction port 31 is provided at the bottom of the pressure tank 30, and a gas vent valve 32 is provided at the top. 05 in the diagram
．． G6 is a flow meter, and G7 is a pressure gauge.

When such a device was operated under various conditions, the liquid (water) tgE entered i160 n/sin, the average air suction amount was 417 sin, and the dissolved liquid was extracted g160 j! /sin
When the amount of circulating fluid was 10 IL/sin when the amount of circulating fluid was only water, a result was obtained in which the amount of precipitated air was 2.5%. However, since this device does not automatically control the amount of intake air, excess air accumulates in the pressure tank 30.

Therefore, it was necessary to measure the liquid level in the pressure tank 30 using a level meter (not shown) and manually operate the gas vent valve 32 or the like to bleed out the excess air. Furthermore, this example required a residence time of 4 minutes, and it was confirmed that the dissolution efficiency was extremely low compared to the previous example.

[Effects of the Invention] According to the method and device for dissolving and transferring gas according to the present invention, the pump and injector mainly use the pump and the injector to atomize the excess gas and disperse it in the liquid, and the fluid is mainly stirred and dispersed in the cyclone. The gas is dissolved in the liquid by stagnation. Further, the injector self-controls the intake air amount while circulating a part of the fluid containing undissolved gas within the system. Therefore, according to the present invention, there is an effect that gas can be efficiently dissolved in a liquid in a short time.

[Brief explanation of the drawing]

FIG. 1 is a mock-up configuration diagram showing one embodiment of the device according to the present invention, FIG. 2(a) is a partially cutaway front view showing the main parts of the pump in the same embodiment, and FIG. A diagram showing the shape of the fluid passage in the pump, FIGS. 3(a) and 3(b) are a plan view and a front view of the cyclone in the same embodiment, and FIG. 4(a)
, (b) is a diagram showing a horizontal cyclone, Fig. 5 (a),
(b) is a plan view and a front view showing another form of the cyclone, FIG. 6 is a sectional view of the injector in the same embodiment, and FIG.
The figure is an overall configuration diagram of a dissolving apparatus having a pressure tank configured for comparison with the apparatus of the same embodiment. ! - Gas dissolution and transfer device (equipment M), 2-pump, 3.3
', 17-cyclone, 14-circulating fluid outlet as overfluoro, 15-liquid outlet as underfluoro, 18-injector, 20-injector inlet, 25-pump suction port, 27-liquid liquid inlet. Patent applicant Norimitsu Nishimura, agent/patent attorney for Nikko Engineering Co., Ltd. Figure 1 Figure 2 (b) Figure 3 (b) Figure 4 Figure 5 (a) (a) (b) Figure 6 Convex

Claims (2)

[Claims] (1) Gas and liquid are force-fed to a cyclone, and the fluid is stirred and retained in the cyclone to disperse and dissolve the gas in the liquid, and at the same time, the gas and liquid are separated by centrifugal force, and the underflow port of the cyclone is At the same time, the liquid containing excess dispersed gas is extracted from the overflow port of the cyclone and passed through the injector, and the gas is sucked by the injector with a suction force that corresponds to the kinetic energy of the fluid passing through the injector. A method for dissolving and transferring a gas, characterized in that, at the same time, a liquid is further added to the fluid and the cyclone is again used to pump the fluid. (2) A pump that pumps gas and liquid, and the gas and liquid supplied from the pump are internally stirred and retained to disperse and dissolve the gas in the liquid, and centrifugal force separates the gas and liquid into a dissolved liquid. The cyclone is extracted from the underflow port, and the liquid containing excess dispersed gas extracted from the overflow port of the cyclone passes through the cyclone, and the gas is sucked into the interior by a suction force that corresponds to the kinetic energy of the passing fluid. A liquid dissolving and transferring device comprising: an injector; and a liquid inlet connected to an inlet of the pump together with an outlet of the injector.