JP2024074192A - Gas-liquid stirring device - Google Patents

Abstract

To solve a problem that conventional gas-liquid stirring devices consume large amounts of gas-liquid power and stirring power.SOLUTION: A gas-liquid stirring device of the invention comprises: a stirring tank in which a liquid is placed; a stirring blade provided in the stirring tank and configured to discharge the liquid to the radial outer side; a stationary blade which is provided at a bottom part of the stirring tank to generate upward flow; and fine air bubble discharge means. The fine air bubble discharge means is provided at a position where circulation flow formed by the stirring blade and the stationary blade occurs. Further, the stirring blade comprises a plurality of flat paddle blades provided radially in a radial direction. The stationary blade comprises a plurality of belt-like plates radially provided. A gap is formed at a center part corresponding to an intersection part of the belt-like plates.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gas-liquid mixing device that aims to improve the efficiency of mixing power and aeration power.

As an example 1 of a conventional gas-liquid mixing device, for example, as shown in FIG. 3, a rotating shaft 2 is suspended from the center of a cylindrical mixing vessel 1 with a bottom containing liquid, and a plurality of mixing blades 3 such as turbine blades are provided at intervals in the vertical direction on the rotating shaft 2, and a baffle 4 extending in the vertical direction is provided on the inner peripheral surface 1b of the mixing vessel 1.

There is also a mechanical gas-liquid mixing device in which, for example, an annular vent pipe (sparger ring) 5 is provided under the lowest mixing blade 3, and multiple gas outlets (not shown) are provided on the upper surface of the peripheral wall of the annular vent pipe 5, and the gas discharged upward from these gas outlets is strongly dispersed by the mixing blade 3 and aerated into the liquid in the mixing tank 1 (Patent Document 1).

For example, as shown in FIG. 4, there is a bubble column type gas-liquid mixing device in which a baffle 4 extending in the vertical direction is provided on the inner peripheral surface of a cylindrical stirring vessel 1 with a bottom containing liquid, and a fine bubble discharge means 6 made of an aeration nozzle that discharges fine bubbles, a ceramic porous body, a fine bubble membrane, or the like is provided at the center of the bottom 1a of the stirring vessel 1, and fine bubbles are discharged from the bottom 1a to mix and stir the gas and liquid in the stirring vessel 1 using aeration energy.

JP 2015-116519 A

However, mechanical and bubble column type gas-liquid mixing devices have the disadvantage of consuming a lot of gas-liquid power and mixing power.

The present invention is intended to eliminate the above drawbacks.

To achieve the above object, the gas-liquid mixing device of the present invention comprises a mixing vessel in which liquid is contained, mixing blades arranged in the mixing vessel for discharging the liquid radially outward, stator blades arranged at the bottom of the mixing vessel for generating an upward flow, and a microbubble emitting means, and the microbubble emitting means is arranged at a position where a circulating flow formed by the mixing blades and stator blades is generated.

The agitating blade is made up of a plurality of flat paddle blades arranged radially in the radial direction, and the stationary blade is made up of a plurality of strip-shaped plates arranged radially, with a gap formed in the center corresponding to the intersection of the strip-shaped plates.

The microbubble emitting means is also characterized in that it is provided at the same height on the inner circumferential surface of the mixing vessel as the mixing blades are provided.

The microbubble emitting means is also characterized by being formed from a membrane that generates microbubbles.

The inner surface of the mixing vessel is also provided with a baffle extending in the vertical direction.

According to the present invention, a low-power mixing technique is used in which the liquid is mixed on the circulating flow formed by the mixing blades and the stationary blades, and the fine bubbles are circulated on the circulating flow formed by the mixing blades and the stationary blades, so that the mixing power and aeration power can be reduced and gas-liquid mixing can be achieved.

FIG. 2 is a longitudinal sectional side view of the gas-liquid mixing device of the present invention. FIG. 2 is an enlarged cross-sectional plan view of the gas-liquid mixing device of the present invention. FIG. 1 is a vertical sectional side view of a conventional gas-liquid mixing device. FIG. 11 is a vertical sectional side view of another conventional gas-liquid mixing device.

The following is an example of how the present invention can be implemented.

Note that parts that are the same as those in the background art are given the same reference numerals and their explanations are omitted.

The first embodiment of the present invention will be described with reference to Figs. 1 and 2.

The gas-liquid mixing device of the present invention comprises a cylindrical mixing vessel 1 with a bottom in which liquid is contained, a rotating shaft 2 suspended in the mixing vessel 1, a mixing blade 7 provided at the lower end of the rotating shaft 2 for discharging liquid radially outward, a stator blade 8 provided at the center of the bottom 1a of the mixing vessel 1 for generating an upward flow, and a microbubble emission means 9 made of a ceramic porous body or a microbubble generating membrane. The microbubble emission means 9 is provided at a position where a circulating flow formed by the mixing blade 7 and the stator blade 11 is generated. For example, the microbubble emission means 9 is provided in contact with or in close proximity to the inner circumferential surface 1b of the mixing vessel 1. 4 is a baffle, but may be omitted.

The stirring blades 7 are, for example, four rectangular flat paddle blades 7a fixed radially to the lower end of the rotating shaft 2, and are provided at the top of the stirring tank 1 in the liquid.

The stator blades 8 are, for example, as shown in FIG. 2, made of linear strips 8a, and the strips 8a are fixed in parallel and radial directions at a distance d from a radial line R passing through the center of the bottom 1a in the mixing vessel 1, for example, four strips, and a gap is formed in the center of the bottom, which corresponds to the intersection of the strips 8a.

The height of the fine bubble emitting means 9 is preferably set to the same height as the stirring blade 7 or slightly lower. When the fine bubble emitting means 9 is set in the upper part of the stirring tank 1 in this way, the pressure head difference can be reduced, which is preferable as it reduces the pump power consumption.

In addition, 9a is a gas introduction pipe of the fine bubble releasing means 9, and 9b is a pump provided on the introduction pipe 9a.

Since the present invention is configured as described above, when the agitator blades 7 are rotated, as shown in FIG. 1, the liquid from the agitator blades 7 is discharged radially outward, hits the inner circumferential surface 1b of the agitator tank 1, and generates a downward swirling flow along the inner circumferential surface of the agitator tank 1. The liquid then reaches the bottom 1a, moves to the center of the bottom 1a, and generates an upward flow in the center due to the stationary blades 8 of the bottom 1a. The upward liquid is then discharged radially outward by the agitator blades 7, and the liquid circulates within the agitator tank 1.

The microbubble generating means 9 is provided in contact with or close to the inner peripheral surface of the agitation tank 1 where the circulating flow is generated, so that the microbubbles from the microbubble generating means 9 ride the downward flow of the circulating flow to the bottom 1a of the agitation tank 1, then rise at the center of the bottom and reach the agitator blade 7, where they ride the circulating flow to mix the gas and liquid.

According to the present invention, the fine bubbles can be carried down and circulated by the circulation flow, so that the stirring power and aeration power can be reduced and gas-liquid mixing can be achieved.

In addition, because the fine bubbles are generated at the top of the tank, there is almost no head difference, which reduces the pump's power consumption and also requires less motor power.

In addition, multiple microbubble membranes may be provided within the circulating flow, and multiple membranes may be provided in the vertical direction.

Reference Signs List 1 Agitation tank 1a Bottom 1b Inner surface 2 Rotation shaft 3 Agitation blade 4 Baffle 5 Vent pipe 6 Fine bubble emitting means 7 Agitation blade 7a Blade plate 8 Stator blade 8a Band plate 9 Fine bubble emitting means 9a Inlet pipe 9b Pump

Claims (5)

a mixing tank capable of containing a liquid;
A stirring blade provided in the stirring tank for discharging liquid radially outward;
A stator blade that generates an upward flow and is provided at the bottom of the mixing tank;
The microbubble discharging means comprises:
The gas-liquid mixing device is characterized in that the fine bubble emitting means is provided at a position where a circulating flow formed by the mixing blades and the stationary blades is generated. The stirring blade is composed of a plurality of flat paddle blades arranged radially in the radial direction,
2. The gas-liquid mixing device according to claim 1, wherein the stator blade is made of a plurality of band-shaped plates arranged radially, and a gap is formed in a center portion corresponding to an intersection of the band-shaped plates. The gas-liquid mixing device according to claim 1, characterized in that the microbubble emitting means is provided at the same height as the mixing blades on the inner circumferential surface of the mixing vessel. The gas-liquid mixing device according to claim 1, characterized in that the microbubble emitting means is formed from a membrane that generates microbubbles. The gas-liquid mixing device according to claim 1, characterized in that a baffle extending in the vertical direction is provided on the inner peripheral surface of the mixing vessel.

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