JPH0258971B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a gas-liquid contact device, and more particularly to a gas-liquid contact device having a porous cylindrical rotating drum, which is improved so as to equalize the bubble diameter. .

[Prior Art] A gas-liquid device in which a porous drum is provided in a tank body so as to be submerged in water, and gas is supplied under pressure into the drum and the drum is rotated to eject air bubbles into the liquid from the circumferential surface of the drum. Contact devices are known (for example, Japanese Patent Publications No. 52-21991 and No. 52-22953).

Such a gas-liquid contact system using a porous cylindrical drum includes a vertical type in which the drum is installed so that its axial direction is substantially vertical, and a horizontal type in which the drum is installed horizontally. The former vertical type (for example, the above-mentioned Japanese Patent Publication No. 52-21991) has a simpler drum pivot mechanism than the latter horizontal type.
It has the feature of being particularly suitable for small size and small capacity specifications.

[Problems to be Solved by the Invention] However, in the conventional vertical rotating drum type gas-liquid contact device, the diameter of the bubbles ejected from the openings on the peripheral surface of the drum differs considerably between the top and bottom of the drum. There was a problem that the dispersion became large.

In other words, since a smaller water pressure (hydraulic pressure) is applied to the upper part of the drum than to the lower part, a large amount of gas is ejected and the bubble diameter tends to increase, and conversely, the bubbles ejected from the lower part of the drum tend to become smaller in diameter. .

When the bubble diameter varies in this way, a problem arises in that the gas-liquid contact effect is reduced accordingly.

[Means for Solving the Problems] The present invention provides a gas-liquid contact device equipped with a vertical rotating drum, in which a partition wall is vertically disposed from a canopy inside the drum so as to leave a space between it and the inner peripheral surface of the drum. At the same time, a communication section was provided at the bottom of the partition wall to communicate between the inside and outside of the partition wall. A throttle was provided between the partition wall and the inner circumferential surface of the drum to impart pressure loss to the gas rising in the space between the partition wall and the inner peripheral surface of the drum.

Note that the gas supply pipe is inserted into the drum from the center of the bottom of the drum.

[Function] In the gas-liquid contact device of the present invention, the gas supplied from the gas supply pipe into the central chamber of the drum goes around the communication part at the bottom of the partition wall and flows between the partition wall and the inner circumferential surface of the drum. rise. Then, they are sequentially ejected from openings provided on the circumferential surface of this drum. At this time, the drum is being rotated, and the gas ejected from the openings is subjected to a shearing action and becomes minute bubbles.

Therefore, in the present invention, a throttle is provided between the partition wall and the inner circumferential surface of the drum, and the gas rising in this area is caused to rise upward due to the pressure loss passing through the throttle (static pressure). ). Therefore, gas is ejected at a lower pressure toward the upper part of the drum side circumferential surface where the liquid pressure (head) is lower, so that the amount of gas ejected is approximately the same on the upper and lower sides of the drum, and the bubbles have a uniform diameter.

[Example] Examples will be described below with reference to the drawings.

FIG. 1 is a front sectional view showing the main part of the configuration of a gas-liquid contact device according to an embodiment of the present invention.

Reference numeral 10 denotes a tank body, and a motor 16 is fixed to a pedestal 14 provided via a support 12. The motor 16 is installed so that its rotating shaft 16a is vertical, and a cylindrical rotating drum 18 is attached to the lower end of the rotating shaft 16a with a nut 20. The drum 18 has a lid and a bottom, and its axis of rotation is in the vertical direction.

This drum 18 has a large number of openings 2 on its side circumferential surface.
2 is provided, and a gas jet nozzle 24 is provided protruding from the outer peripheral side of this opening 22. In this embodiment, the openings 22 are arranged in a grid pattern.

A pedestal 26 is fixed to the bottom surface of the tank body 10, and a gas supply pipe 28 is raised from this pedestal 26. This gas supply pipe 28 penetrates the bottom plate 18a of the drum 18 and reaches near the top inside the drum 18. Further, the drum bottom plate 18b is provided with an opening through which the gas supply pipe 28 is inserted, and a sliding member 30 is provided at the edge of this opening, so that when the drum 18 rotates, the drum 18 is rotated.
8 It is designed to form a pivot at the lower end.

Reference numeral 32 denotes a partition wall, which in this embodiment has a cylindrical shape with a smaller diameter than the drum 18.
The canopy part 18b of No. 8 is vertically installed. This partition wall 32 is smaller in height than the drum 18, and a communication portion 34 is formed between the lower end of the partition wall 32 and the drum bottom plate 18a. Further, between the partition wall 32 and the inner circumferential surface of the drum 18, there is a throttle 36 for giving a passing pressure loss to the gas flow rising therebetween, so that the gas maintains an extremely small pressure upward. are arranged in multiple stages. Note that the lower part of the gas supply pipe 28 is T-shaped,
A flexible tube 38 is connected.

In the gas-liquid contact device having such a configuration, gas is supplied into the rotating drum 18 through the flexible tube 38 and the gas supply pipe 28, and the motor 1
6 is rotated, the gas flows around the communication part 34 at the lower end of the partition wall 32 and between the partition wall 32 and the drum 18.
The liquid rises between the inner circumference and is sequentially ejected from the nozzle 24. Then, due to the shearing action caused by the rotation of the drum 18, it is finely divided into fine bubbles.

In this embodiment, the throttles 36 are provided in multiple stages, and due to the pressure loss when passing through the throttles,
The pressure of the gas rising between the partition wall 32 and the inner peripheral surface of the drum 18 decreases as it flows upward.
Therefore, by appropriately adjusting the opening degree of the throttle 36, the difference between the water pressure and the gas pressure inside and outside the drum 18 in each nozzle 24 can be made almost equal. This makes it possible to eject an equal amount of gas from each nozzle 24 per unit time, and the diameters of bubbles generated from each nozzle 24 are made equal.

Note that before the apparatus of this embodiment starts operating, the drum 18 contains liquid. This liquid is pushed by the gas supplied from the gas supply pipe when the apparatus starts operating, and is also discharged out of the drum 18 by the rotational centrifugal force of the drum 18.

In the above embodiment, since the nozzle 24 is provided in a protruding manner, the gas is ejected at a point where the speed of the liquid rotating together with the drum 18 is reduced, which increases the shearing effect of the ejected gas and makes the bubbles finer. There is an effect. That is, when the drum 18 is rotated, the liquid in contact with the side circumference of the drum 18 also rotates with the drum 18, but the speed of the liquid decreases as it moves away from the surface of the drum 18.

Therefore, the relative velocity difference between the tip of the nozzle 24 and the liquid is larger than that at the surface of the drum 18.
This makes it possible to apply a large shearing force to the ejected gas.

Further, in the above embodiment, the drum bottom plate 18a is configured to be pivotally supported by the gas supply pipe 28 via the sliding member 30, and the drum 18 is supported in two places, upper and lower, and stable rotation can be performed. effective. However, in the present invention, the drum bottom plate is not essential, and a drum with a lid and no bottom may be used. In this case, spokes are installed radially at the bottom end of the drum,
A boss member that loosely fits into the gas supply pipe 28 may be fixed to the tip of the spoke.

In the above embodiment, the partition plates 32 have the same diameter at the top and bottom, but the diameter is not necessarily limited to this. For example, it is also possible to adopt a shape that becomes smaller in diameter toward the bottom, and in this case, the orifice 36 to provide pressure loss
can be omitted. Moreover, it does not have to be cylindrical, but may be polygonal such as hexagonal or octagonal.

[Effects] As described above, according to the present invention, a gas-liquid contact device is provided that is capable of generating microbubbles with a uniform diameter and has high gas-liquid contact efficiency.

The gas-liquid contact device of the present invention can be used in various water treatment devices,
Equipment for supplying air and oxygen to aquaculture fish tanks, gas-liquid contact reaction equipment, gas absorption equipment, wet dust collectors,
It can be extremely suitably applied to various devices such as gas desulfurization equipment.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an apparatus according to an embodiment of the present invention. 10... Tank body, 18... Rotating drum, 22...
Opening, 24... Nozzle, 28... Gas supply pipe, 3
2... Partition wall.

Claims (1)

[Claims] 1. A tank body, a rotary drum with a lid installed in the tank body with the axial direction in a substantially vertical direction and having a large number of gas ejection ports on the side circumferential surface, and a rotary drum installed vertically from the canopy of the rotary drum. A cylindrical partition wall having a diameter smaller than that of the rotating drum, a communication portion between the inside and outside of the partition wall provided at the lower part of the partition wall, and a partition wall disposed between the outer circumferential surface of the partition wall and the inner circumferential surface of the rotating drum. a throttle for imparting a passing pressure drop to the rising gas; a gas supply pipe inserted into the rotating drum from the center of the bottom plate of the rotating drum;
A gas-liquid contact device with