JP5927556B2 - Gas dissolving device - Google Patents

Description

  The present invention relates to a gas dissolving apparatus.

  The present applicant has proposed a gas dissolution apparatus including a dissolution tank that is partitioned into a gas-liquid mixing tank, a large bubble outflow prevention tank, and a gas-liquid separation tank by two partition walls (Patent Document 1).

  In the gas dissolving device of Patent Document 1, fluid is introduced into the gas-liquid mixing tank by ejecting fluid. At this time, the fluid collides with the upper wall and partition walls of the dissolution tank, rebounds, and gradually accumulates at the bottom of the gas-liquid mixing tank. Further, the fluid that collides with the inner surface of the upper wall portion and rebounds collides with the liquid surface of the fluid stored in the gas-liquid mixing tank, and stirs the fluid. The gas and fluid stored in the dissolution tank are mixed by stirring at this time, and when the gas-liquid mixed fluid is ejected, the gas and fluid are mixed together with the gas in the gas-liquid mixed fluid, Dissolution of the gas is promoted, and a liquid in which the gas is dissolved is generated. This is because the gas mixed as bubbles is subdivided by shearing by stirring the fluid, and the surface area in contact with the fluid is increased.

  Thus, the gas dissolving device of Patent Document 1 requires a large amount of fluid to increase the gas-liquid contact area. For this reason, it is a device suitable for dissolving a gas in a fluid having a high flow rate, but it is difficult to dissolve the gas in a fluid having a low flow rate.

  On the other hand, a pressurized gas mixing device (gas) comprising a closed vessel type vessel provided with a pressurized air inlet and a treated water inlet and a rotating plate rotatably supported inside the central position of the vessel. A dissolution apparatus) is known (Patent Document 2). The rotating plate is configured as a bottomed container in which a large number of openings are formed around the rotating plate, and the treated water introduced from the treated water introduction port is supplied to the rotating plate. The treated water supplied to the rotating plate is blown off in the form of water droplets toward the inner peripheral wall of the vessel by the centrifugal force generated by the rotation of the rotating plate. The inside of the vessel is filled with pressurized air blown from the pressurized air inlet, and water droplets fly through the pressurized air to mix the air. The water droplets that have reached the inner peripheral wall of the vessel flow down as a water film around the inner peripheral wall surface, come into contact with the pressurized air, and the air is mixed.

  Thus, the pressurized gas mixing device of Patent Document 2 increases the gas-liquid contact area by flying treated water in the form of water droplets onto the inner peripheral wall of the vessel and flowing down the inner peripheral wall surface of the vessel as a water film. Yes. For this reason, it is considered possible to dissolve the gas even if the treated water has a low flow rate.

JP 2010-227782 Japanese Patent Laid-Open No. 10-235174

  However, in the pressurized gas mixing device of Patent Document 2, the treated water that collides with the inner peripheral wall of the vessel rebounds depending on the outflow speed of the treated water from the rotating plate, and a water film may not be formed on the inner peripheral wall surface. There is a problem that it is difficult to adjust the rotation speed of the rotating plate. When the treated water bounces off the inner wall of the vessel, the treated water usually flows out of the rotating plate at a high speed and the bounce speed is also high, so the contact time with the air is short, and the air is put into the treated water. It cannot be dissolved sufficiently.

  The present invention has been made in view of the circumstances as described above, and an object thereof is to provide a gas dissolving apparatus capable of efficiently dissolving a gas even with a low flow rate fluid.

In order to solve the above problems, a gas dissolving apparatus of the present invention is a gas dissolving apparatus provided with a cylindrical dissolution tank, and the dissolution tank has a hole penetrating vertically, A droplet generation unit that divides the inside into an upper tank and a lower tank is provided, and the lower tank is a gas dissolution tank provided with an outflow pipe connection part having a liquid outlet, and the outflow pipe connection part is The liquid outlet is provided laterally along the inner surface of the bottom wall so that the liquid outlet is located in the vicinity of the axial center of the bottom wall of the dissolution tank. On the upper side of the outlet, a plurality of rectifying plates extending in the vertical direction are arranged radially from the axial center of the dissolution tank toward the side wall portion, and the fluid supplied from the upper side of the droplet generation unit is the droplet A droplet is generated by passing through the hole of the generation unit, and this droplet is dropped by The gas is supplied to the gas dissolution tank, and the gas is dissolved in the droplets via the gas-liquid interface of the droplets, and a liquid in which the gas is dissolved is generated. It flows out of the gas dissolution tank.

  In this gas dissolving apparatus, it is preferable that the droplet generating unit has a plurality of holes formed at substantially equal intervals.

  According to the gas dissolving apparatus of the present invention, gas can be efficiently dissolved even with a low flow rate fluid.

It is the schematic diagram which showed one Embodiment of the gas dissolving apparatus of this invention, (a) is a front view, (b) is a top view. It is a perspective sectional view in the BB section of the gas dissolving device shown in Drawing 1 (b). It is AA sectional drawing of the gas dissolving apparatus shown to Fig.1 (a).

  FIG. 1 is a schematic view showing an embodiment of the gas dissolving apparatus of the present invention, where (a) is a front view and (b) is a plan view. FIG. 2 is a perspective sectional view of the gas dissolving apparatus shown in FIG. FIG. 3 is a cross-sectional view taken along line AA of the gas dissolving apparatus shown in FIG.

As shown in FIG. 1-3, the gas dissolving apparatus 1 includes a substantially circular upper wall portion 2a, a substantially circular bottom wall portion 2b opposed to the upper wall portion 2a, and the upper wall portion 2a and the bottom wall portion 2b. And a side wall portion 2c surrounding the periphery of the tank, a vertically long and cylindrical dissolution tank 2 is provided. In the dissolution tank 2, a gas that becomes a solute such as air in a liquid in which a gas to be described later is dissolved is stored.
The inside of the dissolution tank 2 is partitioned into two tanks, an upper tank 4 and a lower tank 5, by plate-like partition walls 3 provided in a direction orthogonal to the axial direction of the dissolution tank 2. The lower tank 5 constitutes a gas dissolution tank 6.

In the dissolution tank 2, an inflow pipe connecting portion 10 having a fluid introduction port 9 is provided in the axial direction near the axial center of the upper wall portion 2 a. One end portion of an inflow pipe that sends out a fluid (liquid) such as water serving as a solvent is connected to the inflow pipe connection portion 10. In addition, the position where the inflow pipe connecting portion 10 is provided is not limited to the example shown in the drawing, and any position can be used as long as it is a position above a droplet generation portion described later.
A fluid is supplied to the upper tank 4 of the dissolution tank 2 through the fluid inlet 9 of the inflow pipe connection 10. The flow rate of the fluid supplied from the fluid introduction port 9 may be an amount that can generate droplets in the droplet generation unit 8 described later. Prior to supplying the fluid to the upper tank 4, the fluid may be mixed with the same type of gas as the gas stored in the dissolution tank 2 to be a gas-liquid mixed fluid. Hereinafter, the fluid alone (liquid) and the gas-liquid mixed fluid are collectively referred to as “fluid”.

  The partition wall 3 is formed with a hole 7 penetrating vertically, and the partition wall 3 constitutes a droplet generation unit 8. The upper tank 4 and the gas dissolution tank 6 communicate with each other through this hole 7. As shown by an arrow P in FIG. 2, the fluid supplied to the upper tank 4 passes through the holes 7 and is supplied as droplets to the gas dissolution tank 6. Although pressure may be applied to the fluid supplied to the upper tank 4 to facilitate passage through the holes 7, in this case, the initial velocity when the generated droplets fall is infinitely zero, That is, it is preferable to reduce the pressure applied to the fluid so that it flows down in a free-fall state. It is desirable that the generated droplets flow down by free fall because the contact time between the droplets and the gas in the gas dissolution tank 6 can be extended. The size and shape of the holes 7 are appropriately set so that droplets can be generated, and are determined by the viscosity of the fluid, the specific gravity of the fluid, and the like. For example, when the fluid is water, it can be a hole having a substantially circular shape with a hole diameter of 0.1 to 2 mm.

In the droplet generation unit 8, a plurality of holes 7 may be provided. In this case, each hole 7 may have the same size and the same shape, or may be different in each hole 7. The larger the number of holes 7, the more the number of generated droplets increases, and a liquid in which a gas is dissolved is more preferably generated. As for the arrangement of the holes 7, the distance between the adjacent holes 7 may be set according to the size and shape of the holes 7. In the example shown in FIGS. 1-3, the adjacent holes 7 and the holes 7 are arranged at substantially equal intervals so that the droplets are uniformly formed on the entire surface of the partition wall 3 and the droplets do not aggregate during the flow.
The size, shape, number, arrangement and the like of the holes 7 can be set in consideration of the position of the fluid introduction port 9 and the flow velocity of the fluid flowing into the upper tank 4 from the fluid introduction port 9.

The droplets generated in the droplet generation unit 8 flow down by being dropped, and are supplied to the gas dissolution tank 6 positioned below the droplet generation unit 8.
By making the fluid into droplets, the ratio of the gas phase (gas) to the liquid phase (fluid) increases, and the contact area between the gas phase and the liquid phase (gas-liquid contact area) increases. Since the gas dissolves in the fluid through the gas-liquid interface, the increase in the gas-liquid contact area increases the rate of dissolution of the gas into the fluid, thereby efficiently dissolving the gas. Since the flow rate of the fluid supplied to the droplet generation unit 8 may be an amount that can generate droplets, the gas dissolving device 1 of the present embodiment can efficiently dissolve the gas even with a low flow rate fluid. it can.

  Thus, the droplet generated by the droplet generation unit 8 flows down in the gas phase in the gas dissolution tank 6, and the gas is dissolved in the droplet (fluid) via the gas-liquid interface of the droplet, A liquid in which a gas is dissolved is generated. This liquid gradually accumulates at the bottom of the gas dissolution tank 6. In addition, the liquid droplets that flow down collide with the liquid level of the stored liquid, and stir the liquid immediately below the liquid level.

  The gas and the liquid stored in the dissolution tank 2 are also mixed by stirring at this time, and the dissolution of the gas is promoted. On the other hand, turbulent flow is also likely to occur, and droplets may aggregate while falling, resulting in a decrease in dissolution efficiency. Therefore, the current plate 11 can be provided in the gas dissolution tank 6 as in the present embodiment. The current plate 11 extends in the vertical direction (vertical direction), and is provided on the upper side of the liquid outlet 12 described later. You may provide in the position below the liquid level of the liquid stored in the gas dissolution tank 6. FIG. The flow of the liquid generated just below the liquid level is rectified by the flow straightening plate 11, and the flow direction becomes uniform in the vertical direction as indicated by an arrow Q in FIG. Moreover, aggregation of droplets can be suppressed, and as a result, a decrease in dissolution efficiency can be suppressed.

  Since the rectifying plate 11 may cause a pressure loss of the liquid flow, it is preferable to make the thickness thin in order to suppress the pressure loss as low as possible. On the other hand, with respect to the length in the vertical direction, the longer the length, the more it contributes to liquid rectification, and the liquid flow direction can be controlled. Further, in order to rectify the liquid more effectively, the number of rectifying plates 11 is preferably as large as possible. From such a viewpoint, it is desirable to arrange the plurality of rectifying plates 11 radially from the axial center of the dissolution tank 2 toward the side wall 2c as in the present embodiment.

The gas dissolution tank 6 is provided with an outflow pipe connection portion 13 having a liquid outlet 12 on the bottom wall portion 2 b of the dissolution tank 2. The outflow pipe connecting portion 13 is provided in the lateral direction along the inner surface of the bottom wall portion 2b so that the liquid outlet 12 is located in the vicinity of the axial center of the bottom wall portion 2b. The outflow pipe connecting portion 13 is connected to one end portion of an outflow pipe that sends out the gas-dissolved liquid generated in the gas dissolution tank 6 to a supply section such as a bathtub.
Since the outflow pipe connecting portion 13 is provided in the bottom wall portion 2b of the dissolution tank 2 in this way, even if bubbles due to undissolved gas are mixed in the liquid, large bubbles existing near the liquid surface Outflow can be suppressed. Bubbles are densely present on the upper side, and large bubbles near the liquid surface do not exist so much near the bottom away from the liquid surface. Since the liquid flows out from the bottom of the gas dissolving tank 6 to the outside of the gas dissolving tank 6 through the liquid outlet 12 of the outflow pipe connecting portion 13 and is taken out, the outflow of large bubbles is suppressed.

  As described above, the gas dissolving apparatus of the present invention uses fluid as droplets to increase the contact area between the gas phase and the liquid phase, and dissolves gas in the fluid with high dissolution efficiency in the gas phase in the gas dissolving tank. ing. Since even a low flow rate fluid can be formed into droplets, the gas dissolving device of the present invention can efficiently dissolve a gas even with a low flow rate fluid. In addition, energy saving has been realized, such as the generation of droplets and gas dissolution in droplets without requiring a special drive or power source, etc., and excellent maintenance and easy handling. It is a simple structure.

DESCRIPTION OF SYMBOLS 1 Gas dissolving apparatus 6 Gas dissolving tank 7 Hole 8 Droplet production | generation part 11 Current plate 12 Liquid outlet

Claims (2)

A gas dissolving device comprising a cylindrical dissolution tank,
The dissolution tank has a hole that penetrates up and down, and includes a droplet generation unit that divides the inside of the dissolution tank into an upper tank and a lower tank,
The lower tank is a gas dissolution tank provided with an outflow pipe connection having a liquid outlet,
The outflow pipe connecting portion is provided in a lateral direction along the inner surface of the bottom wall portion so that the liquid outlet is located near the axis of the bottom wall portion of the dissolution tank,
In the gas dissolution tank, on the upper side of the liquid outlet, a plurality of rectifying plates extending in the vertical direction are arranged radially from the axial center of the dissolution tank toward the side wall,
The fluid supplied from the upper side of the droplet generation unit passes through the hole of the droplet generation unit to generate a droplet. The droplet is supplied to the gas dissolution tank by dropping, and the droplet gas is discharged. The gas is dissolved in the liquid droplets through the liquid interface, and a liquid in which the gas is dissolved is generated, and the liquid flows out of the gas dissolution tank from the liquid outlet through the outflow pipe connection portion. Gas dissolving device.   The gas dissolving device according to claim 1, wherein the droplet generation unit has a plurality of holes formed at substantially equal intervals.

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