JPS63229133A - Gas-liquid contact device - Google Patents

Abstract

PURPOSE:To enhance gas-liquid contact efficiency by providing a gas-liquid contacting device constituted of a revolving drum with a number of gas jetting holes on the side peripheral surface, a driving gear for revolution of the revolving drum and a gas feeding means connected with the revolving drum. CONSTITUTION:While water is flowed through a flow channel inside a channel 1, gas jets out of an opening 2a in the form of very fine foams by revolving a revolving drum 2 and introducing gas into the revolving drum 2. As above- mentioned, foams of small diameters are generated in a gas-liquid contacting device by the action of a revolving drum 2, and very efficient gas-liquid contact is carried out because of the large specific surface areas of foams and the long residence time of foams is water. Further, as the fine foams generated in said gas-liquid contacting device are flowed together with running water downstream while being diffused in the width direction of the channel 1, the foam distribution area is widened and the gas-liquid contact efficiency is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a gas-liquid contact device, and more particularly to a gas-liquid contact device having a perforated cylindrical rotating drum.

[Prior art] In general, in the unit operations of chemical engineering, the operation of bringing gas and liquid into contact (hereinafter referred to as gas-liquid contact) to perform reactions, absorption, dust removal, etc. is a very important field, and this method is Various devices have been used in the past to accomplish this.

namely, tray towers, packed towers, showers, venteri scrappers, pudges, etc.

Each of these devices has advantages and disadvantages, and each is used appropriately.

The inner bubbler, which is a method in which gas is blown into the liquid to form bubbles and float in the liquid, and the gas and liquid come into contact with each other along the way, has a simple device configuration. Various types of stirring blades such as stirring blade 2 are known.

In addition, the present applicant has proposed a method in which a rotating drum is mounted in a main casing that stores liquid at least enough to submerge the rotating drum, and a large number of injection holes provided in the circumferential direction and longitudinal direction of the rotating drum are connected to ejection pipes. A device for blowing gas into a liquid has been proposed in which the gas emitted from the tip of the ejection tube is directly converted into bubbles by fixing the ejection tube and protruding the tip of the ejection tube by an appropriate length from the outer wall of the rotating drum. (Tokuko Showa 52-2
2953).

[Problems to be Solved by the Invention] The conventional gas-liquid contact device described above has a large pressure loss and is difficult to generate uniformly fine bubbles, so it is not often used for large-scale practical use. It wasn't.

On the other hand, although the gas-liquid contact device proposed in Japanese Patent Publication No. 52-22953 solves these problems, it requires a casing large enough to accommodate the drum, which increases the cost of the device construction.

[Means for solving the problems] The gas-liquid contact device of the present invention includes a groove body or a tank body for liquid circulation;
A rotating drum having a large number of gas ejection ports on its side circumferential surface, installed in the groove body or tank body with its axial direction intersecting the liquid flow direction and substantially horizontally, and a rotation drive device for the rotating drum. and a gas supply means connected to the rotating drum.
It has the following.

[Function] In the gas-liquid contact device of the present invention, since the drum is rotatably provided by being submerged in running water (liquids other than water may also be collectively referred to as water in this specification), Fine air bubbles are obtained by the rotation of the drum, and the generated fine air bubbles are distributed in the passage width direction of the groove body and widely distributed in the flow direction, thereby improving the gas-liquid contact efficiency.

[Examples] Hereinafter, the present invention will be described in further detail with reference to examples shown in the drawings.

FIG. 1 is a perspective view showing the configuration of a gas-liquid contact device according to an embodiment of the present invention, and FIG. 2 is a schematic side view.

Reference numeral 1 denotes a groove body, on which a rotating drum 2 is installed horizontally and in a direction perpendicular to the flow direction.

The rotating drum 2 is pivotally supported at both ends by bearing members 3, and a motor 5 is connected to a support shaft 4. Reference numeral 6 is a gear box.

The rotating drum 2 has a large number of gas ejection openings 2a on its surface.
The piping 8 is connected via the hollow support shaft 7.
Gas can be introduced from

In the gas-liquid contact device configured as described above, the rotary drum 2 is rotated while water is flowing through the flow channel in the groove body 1, and gas is introduced into the rotary drum 2. Then, the gas is ejected from the opening 2a in the form of fine bubbles.

Conventionally, a gas-liquid contact device in which a rotating drum is submerged in water in a casing is known, but the gas-liquid contact device of the present invention is improved in that the water in which the rotating drum is submerged is circulated. ing.

Generally, when a rotating drum is rotated in a liquid, as shown in FIG.
When the nozzle 2b protrudes by A, the rotating drum main body rotates, so that the nozzle 2b and the gas are separated. At that time, diameter A
Bubbles are generated. The diameter A is determined by the circumferential speed of the rotating drum 2 and the speed of gas ejected from the nozzle 2b, and is usually 10 to 100 μm. On the other hand, the bubbles generated by a non-rotating stationary dispersion device such as a bubbler are determined by the diameter of the bubble ejection nozzle and are usually 1000 μm, as shown in Figure 5.
That's all. Therefore, with conventional devices such as bubblers, air bubbles with a considerably large diameter are blown into the water as described above, and the contact efficiency is reduced due to the small specific surface area of the air bubbles, and the air bubbles quickly float up. This resulted in a decrease in contact efficiency.

In contrast, in the device of the present invention, bubbles with a small diameter are obtained by the action of the rotating drum, so the specific surface area of the bubbles is large, and the residence time in water is long, resulting in extremely efficient gas-liquid contact. .

In the present invention, since the rotating drum is installed in a direction perpendicular to the flow, the generated fine air bubbles are pushed by the flowing water and flow downstream while being dispersed in the width direction of the groove body, so that the air bubble distribution area is widened. spread, which also increases the contact efficiency.

In the present invention, the rotating drum 2 may be driven by a submerged drive system using a submerged motor.

Further, in the present invention, the opening provided on the circumferential surface of the rotating drum may have various shapes such as a circular hole or a slit. Further, nozzles may be provided protruding from the circumferential surface of the rotating drum. Furthermore, in addition to the groove body, the present invention can also be applied to a tank body through which water flows in a desired direction.

Hereinafter, the present invention will be explained in detail by giving experimental examples.

Experimental Example 1 "Ki 1 Ri" The groove body 1 was used as a neutralization wastewater treatment groove for alkaline wastewater, and CO2 gas was supplied into the rotating drum 2.

The main specifications are as follows.

Rotating drum diameter: 114.3 mm Rotating drum length: 30 cm Rotating drum rotation speed: 120 rpm Number of openings on the rotating drum: 32 Diameter of openings: 12.7 mm Conductor width: 60 cm Flow rate of alkaline waste liquid: 30 n'l"/Hr According to the example of the present invention, fine It was observed that a large amount of bubbles were generated.The relationship between the amount of CO2 gas blown in (kg) per unit of wastewater and the concentration of residual alkali solids in the neutralized wastewater is shown in Figure 3.

Alkaline waste water was neutralized in the same manner as in the above-mentioned example of the present invention, except that a fixed air diffuser plate was used instead of the salt and blue rotating drum. The results are shown in Figure 3.

From FIG. 3, it is clear that according to the present invention, alkali can be neutralized extremely efficiently.

The specifications of the diffuser plate in this comparative example are as follows.

Diameter: 60 mm Opening size: Approximately 120 μm Experimental Example 2 Ki 1 Ri 1 The device of the present invention was used as shown in Fig. 6 with an inlet BOD of 810 ppm.
, was applied to an industrial wastewater treatment aeration tank with a flow rate of 100 rn''/day, and its treatment efficiency was investigated. In Fig. 6, 10 is the tank body and 11 is the rotating drum.
Shown in the table.

The main specifications are as follows.

Rotating drum length: 2500mm Diameter: 300mm Rotation speed: 460rpm Number of openings: 96 Diameter of openings: 12.7mm Aeration air amount: 0.72Nrli'/min Aeration shape: 3m (W+) x 3m (H+) x7m
(L+) The following week, the treatment was carried out in the same manner as in the above-mentioned example of the present invention using an aeration tank equipped with a fixed aeration pipe as shown in Figure 7, with an aeration air amount of 1.44 Nd1 min, and the effect was investigated. . 7th
In the figure, 20 is a tank body, and 21 is an aeration pipe.

The main specifications are as follows.

Diameter between aeration pipes: 150 to 500μm Aeration tank shape: 3m (W2) x 3m (H2)
x9m (Lv) Table 1 As is clear from Table 1, the device of the present invention has a larger gas-liquid contact capacity than the conventional one using a diffuser plate, and the aeration tank MLSS (PPm) has a larger capacity than the conventional one. 1.4 times (□-1,4
) is now possible. Therefore, not only the BOD removal rate is improved, but also the aeration tank capacity can be reduced.

Furthermore, the oxygen dissolution efficiency (oxygen utilization efficiency) is high, and the amount of supplied air can be halved.

Therefore, it is clear that according to the present invention, equipment costs and running costs can be significantly reduced.

[Effects of the Invention] As described above, according to the present invention, there is provided a gas-liquid contacting device that is capable of efficiently dispersing fine bubbles, has a long bubble residence time, and has high gas-liquid contact efficiency. . In the gas-liquid contact device of the present invention, since the gas-liquid contact efficiency is high, it is possible to increase the amount of water passing through the groove or the tank, or to make the groove or the tank smaller. In addition, the present invention does not require a casing for accommodating the rotating drum, and the device configuration cost and running cost are also low.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of an embodiment of the device of the present invention, Fig. 2 is a sectional view of the same side, Fig. 3 is a graph 1 showing experimental results, and Fig. 4 is a longitudinal sectional view of main parts showing an embodiment of the invention. FIG. 5 is a longitudinal sectional view showing an example of a conventional device. 6 and 7 are transparent perspective views showing the outline of the tank body of the industrial wastewater treatment aeration tank used in Experimental Example 2, with FIG. 6 showing an example of the present invention and FIG. 7 showing a conventional example. 1...Groove body, 2...Rotating drum, 5...
··motor.

Claims (1)

[Claims] (1) A groove body or tank body for liquid circulation, and a large number of gas jets on the side circumferential surface, which are installed in the groove body or tank body with the axial direction intersecting the liquid flow direction and approximately horizontally. A gas-liquid contact device comprising: a rotating drum having an outlet; a rotational drive device for the rotating drum; and a gas supply means connected to the rotating drum.