JPH01168322A - Multistage fine bubble generator - Google Patents

Abstract

PURPOSE:To effectively utilize a gaseous raw material by providing a plurality of rotors at a suitable intervals on a shaft rotated at high velocity in liquid contained in the same tank and allowing gas fed through a feed pipe to be finely bubbled via the rotor in order from the lower part to the upper part. CONSTITUTION:A plurality of rotors 1 are provided at the suitable intervals on a shaft 2 which is provided in liquid 6 contained in the same tank 5 and rotated at high velocity. The tip of a gas feed pipe 3 inserted into the tank 5 from the outside is opened to the underside of the lowermost rotor selected from among these rotors 1 and the gas fed through the feed pipe 3 allows to be finely bubbled via the rotor in order from the rotor 1' of the lower part to the upper part 1. As a result, effective treatment of difficultly reactive gas, enhancement of utilization efficiency of a specified component incorporated in a gaseous raw material and effective utilization of the gaseous raw material can be contrived and also the title bubble generator can be utilized for an equipment necessitating uniform reaction velocity in respective parts e.g., a sewage disposal equipment due to activated sludge.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention aims to effectively treat refractory gases, improve the utilization efficiency of specific components in the raw material gas, and effectively utilize the raw material gas. The present invention relates to a multistage fine bubble generator that can be used in devices that require high reaction speeds, such as sewage treatment devices using activated sludge.

(Prior art) Conventional gas-liquid contact devices and self-priming microbubble generators are disclosed in Japanese Patent Publication No. 13121/1983 and Japanese Patent Publication No. 1942/1983.
Publication No. 4, Japanese Patent Publication No. 58-29127, Japanese Patent Application Publication No. 1983
The one shown in Japanese Patent No. 35832 has been proposed. First, the gas-liquid contact device shown in Japanese Patent Publication No. 43-13121 is
There is only one rotor, which is solid, hollow, or has a bottom, and a gas inlet is installed below the rotor. Furthermore, the microbubble generator disclosed in Japanese Patent Publication No. 58-29127 has one rotor, and the surface corresponding to 1710 to 1/3 of the outer circumferential surface has protrusions of uniform height in the form of vertical stripes at uniform intervals. It happens in stages.

Furthermore, the self-priming microbubble generator disclosed in JP-A No. 61-35832 has one rotor, has lids on both the upper and lower ends, has radial blades on the upper or lower surface, and has a center line on the outer peripheral side. Parallel vertical striped ridges are planted, and gas sucked in from the outside is supplied to the blades.

What is shown in each of the above publications is a case where only one rotor is provided in the liquid, but what is shown in Japanese Patent Publication No. 51-19424 is a case in which multiple rotors are installed on one drive shaft at intervals. It is installed after the One rotor is installed in each liquid tank, which is partitioned into an upper and lower part by a partition wall.
The liquid in each tank is communicated through an overflow pipe that connects the upper and lower tanks, and air bubbles generated in the lower tank are transferred to the upper tank through an opening provided in the center of the partition wall. It is now possible to do so.

(Problems to be solved by the invention) However, among the conventional devices,
Publication No. 21, Japanese Patent Publication No. 5B-29127, Japanese Patent Publication No. 6
Since each of the devices shown in Publication No. 1-35832 has one rotor, it is necessary to increase the liquid level above the rotor in order to effectively treat refractory gases or effectively utilize raw material gases. Therefore, there were problems such as the need to increase the gas supply pressure.

Furthermore, in the device shown in Japanese Patent Publication No. 51-19424, a plurality of rotors are provided on one drive shaft in multiple stages with vertical intervals, but in this case, each rotor is separated by a partition plate. Each type is used in a tank having a gas phase and a liquid phase, and a plurality of each type are stacked one above the other. Therefore, gas is first supplied to the rotor at the bottom, and the bubbles are then supplied to the lower part of the rotor above it through the gas layer at the top of the tank.
After all the bubbles that have been made fine by the rotor at the bottom are extinguished in the gas layer, they are collected again and made fine again by the next rotor at the top. Therefore, this is not a multi-stage process, but each type is independent, and it is just a stack of multiple layers one above the other.Moreover, an overflow pipe is installed to keep the various liquid levels constant, and the gas supply pressure is ,
That is, it is necessary to keep the amount of gas supplied constant, which poses problems such as moderate operational difficulties and a complicated structure.

The present invention was proposed in order to solve the above-mentioned conventional problems. Among the fine bubbles generated in the lowermost rotor, many relatively large bubbles gather around the axis. The purpose of this is to further refine the structure using a rotor.

(Means for Solving the Problems) Therefore, the present invention provides a plurality of rotors disposed at appropriate intervals on a shaft that is disposed in the liquid in the same tank and rotates at high speed. The tip of a gas supply pipe inserted into the tank from the outside is opened on the bottom surface of the lowest rotor, so that the supplied gas is turned into fine bubbles from the lower rotor through the upper rotor. It is intended to be used as a means to solve problems.

(Function) When multiple rotors are rotated simultaneously by the rotation of the shaft and gas is supplied from the gas supply pipe to the bottom surface of the lowest rotor, the gas becomes fine bubbles, and relatively large bubbles move toward the center of the shaft. It gathers in large quantities in the upper part of the rotor, rises to the position of the rotor above it, becomes finer again, and increases the gas-liquid catalytic reaction.

(Embodiments) The present invention will be described below with reference to embodiments shown in the drawings. FIGS. 1 and 2 show different embodiments of the present invention.

Now, the rotor 1 of the present application is similar to the conventional Japanese Patent Publication No. 43-131.
Publication No. 21, Japanese Patent Publication No. 58-29127, Japanese Patent Publication No. 1983
The rotor shown in Japanese Patent No. 1-35832 can be used. In other words, the Mitsugi and Hollow letters are cylindrical with a bottom and a flat outer circumferential surface, and the outer circumferential surface is flat.
A cylindrical shape with 6 protrusions of equal height arranged in vertical stripes at uniform intervals, a cylinder with lids on both the top and bottom, blades on the lower surface, and vertical striped ridges parallel to the center line on the outer circumferential side. You can use the following. In addition, in FIGS. 1 and 2, 2 is the rotor axis center line, 3 is the gas supply pipe, 4 is the baffle plate, 5 is the tank, and 6
is a liquid, and blades 7 are provided on the lower surface of the rotor 1' at the lowest position in FIG.

This will be explained in detail below using the following specific examples.

Specific Example A9 The number of rotations was kept constant, and a case with one rotor and a case with two rotors were compared.

(1) Put 20 J of 0.2 mol of sodium sulfite solution into a transparent acrylic cylindrical container with an inner diameter of 200 mmφ and a height of 750 wmh as shown in Fig. 1, and the rotor is 50 mmφ x 75
TMB transparent acrylic cylindrical body, with 12 vertical stripes 311 mm wide, 31 meters high, and 9 meters long protruding from the center of its outer circumferential surface at equal intervals. The rotation speed was maintained at 250 OR, P, M, and air was supplied from the outside to the inside of the rotor at a rate of 101/min while being measured with a flow meter.

In addition, four acrylic tubes with an inner diameter of 11 m, an outer diameter of 205 m, and a height of 745 mm were installed on the SUS bottom plate symmetrically with respect to the central axis at the midpoint between the central axis and the vessel wall. The introduced air was made into fine bubbles and reacted. Experiment 1
Samples are collected and analyzed every 0 minutes, the pH is measured, the rotation speed,
The results obtained by measuring current, voltage, and power are shown in Table 1. The oxygen utilization efficiency in Table 1 means that Na, SO, contained in 0.2 mol of sodium sulfite solution 201 are 5.
04 gr, the amount of oxygen required to oxidize all of it is 6
It is 4gr.

The amount of air including 02 of 64gr is 275.86gr, and the specific gravity of air is 1.2928gr/l, so it is 213.38 ji! becomes. In this case, since the amount of air supplied to the container until the reaction is completed is 6 days 01, the amount of air used for oxidation is 02, that is, the oxygen utilization efficiency is 31.38
%.

(2) To configure a multi-stage fine bubble generator, (1)
It is installed coaxially with the lowermost rotor so that the bottom surface of the upper rotor is located 20 on apart from the lid surface of the lowermost rotor. The upper rotor is a transparent acrylic cylindrical body measuring 50 Tomomi φ x 75 m++h, with a lid and a bottom at the top and bottom, and a vertical stripe with a width of 3 nm, a height of 3 fins, and a length of 9 ml in the central band on the outer peripheral side of the cylinder. 12 protrusions were placed at equal intervals. The size of the reaction vessel, the concentration and volume of sodium sulfite, the amount of air supplied, and the rotation speed of the rotor were all the same as in (1) above, and the results obtained were TI
) are listed in Table 1 for convenience of comparison.

Table 1 (Comparison between 1 rotor and 2 rotors) B6 rotor 1
When the speed is set to high speed, and when the speed is relatively low in (2) of the specific example.
Comparison of power and oxygen utilization efficiency between stages.

(3) R, P of the lowest rotor described in specific example (1),
When M is set to 3500 and 4500, and a specific example (2
Table 2 also shows the case of two-stage rotor with R, P, M, and 2500 as described in ).

Table 2 shows that rather than operating the rotor at high speed and consuming a large amount of power, increasing the number of rotors at low speed results in lower power consumption, much higher oxygen utilization efficiency, and There was a bright hope that the height could be lowered.

Effect of multi-stage rotor of CO self-priming micro bubble generator.

(4) In the case of self-priming type, the bottom rotor is 50mmφ×
Eight acrylic blades with a height of 16 wm, a width of 17 fl, and a thickness of 3 mm were planted perpendicularly and radially to the bottom lid of the 75 mb cylinder, and the center of the cylindrical body was placed on the side of the cylindrical body. Twelve vertical stripes with a width of 3 long, a height of 3, and a length of 9 are parallel to the line, their heads aligned on a line 7.5n away from the lid surface, and arranged with the heads facing down. facing down, diameter 17NMφ
Mounted on the 5US304 rotating shaft, one side has a diameter of 200 fins.
, the center line is a vertical pipe with an inner diameter of 12 φ that leads from the hole in the center of the bottom of the transparent acrylic reaction tower to the outside of the tower, and from the imaginary plane formed by the blades of the rotor at the upper end of the pipe. A hard plastic disc with a diameter of 75flφ is installed parallel to this at a distance of 31 mm, and the liquid is sucked in from outside the tower by the self-priming effect accompanying the vortex generated in the surrounding liquid by the high speed rotation of the rotor. The air passes through the aforementioned vertical pipe with an inner diameter of 12B, and after adjusting the intake air pulsation outside the bottom of the tower, it is connected to a flow meter to measure the amount of self-suctioned air, and calculate the rotation speed, power, and oxygen utilization efficiency at this time. were calculated and shown in Table 3.

(5) For the lowermost rotor, use the one in the specific example (4) as is, and set the distance from the upper end of this rotor to the lower end of the upper rotor by 200 cm, and make a 5US30 with a diameter of 17 s*φ.
It was installed on a rotating shaft manufactured by No. 4. The upper rotor is exactly the same as that described in Example (2). The rotation speed of the rotor is shown in a specific example (
41(5), the rotational speed at which the flow meter indicated IQ It /min was adopted and is listed in Table 3 together with the electric power and oxygen utilization efficiency.

Table 3 (Effects of multi-stage self-priming microbubble generator) Since the above cases are based on the oxidation of sodium sulfite solution with air, oxygen is identified as a specific component in the gas, and its utilization efficiency is shown. However, for example, when exhaust gas from semiconductor manufacturing is treated, the semiconductor gas becomes a specific component, and the removal efficiency of these components is indicated. In addition, although the case where one upper rotor is used is illustrated above due to the experimental equipment, even higher efficiency is expected if the number of upper rotors is increased and the diameter is changed depending on the situation at the field of application.

(Effects of the Invention) Since the present invention is configured as explained in detail above,
This provides the following effects.

(b) In terms of power consumption, the lowermost rotor first turns the gas into fine bubbles in the liquid phase, forming a gas-liquid mixture with a small specific gravity, and the upper rotor rotates within that, so multiple The individual power consumption of the top rotor is much smaller than that of the bottom rotor.

(b) Also, from the point of view of the utilization efficiency of specific components in the gas, the rotation speed when the diameter of the lowest rotor is kept constant and the rotation speed is increased to maximize the utilization efficiency of the specific components in the gas. If the number of rotations is N, and the power consumption is QK-, then by simply arranging one rotor of the same diameter coaxially with this lowest rotor and spaced apart from it by a certain distance, the total number of rotations can be reduced to approximately N/2. By reducing the number of times, power consumption can be reduced to 0.58QK-, and the utilization efficiency of specific components in the gas can be reduced by 15 to 2.
It can be improved by as much as 0%.

(c) If the lowest rotor is also equipped with an intake device, after ensuring the rotational speed necessary for a certain amount of intake, place one rotor of the same diameter on the same axis with a predetermined distance apart. They found that if the same amount of air is continued to be taken in, the power consumption will increase slightly, but the rotational speed will decrease by about 5%, and the utilization efficiency of specific components in the gas will improve by about 10%. In this case, when considering the plant as a whole, the effect of reducing power consumption by using the self-priming system in combination is significant.

[Brief explanation of the drawing]

1 and 2 are longitudinal cross-sectional views of a multi-stage fine bubble generator showing an embodiment of the present invention, respectively. Explanation of main parts of the diagram 1-・Rotor 2・・1 rotor axis center line 3-・
Gas supply pipe 5-・Tank 6-Liquid Figure 1 Figure 2 6...Liquid procedure amendment March 4, 1986 Director General of the Patent Office Kunio Ogawa 1, Patent Application for Indication of Case 1988-324845 No. 2, Name of the invention Multi-stage micro bubble generator 3, Relationship with the case of the person making the amendment Patent applicant name: Japan Industrial Technology Co., Ltd. 4, Agent 6, Column for detailed explanation of the invention subject to amendment, Drawings The statement "measured at this time" in the brief explanation column, content 1 of drawing correction, page 12, line 8 of the specification, will be corrected as follows. "Measurements were made. At this time, only the baffle plate 4 shown in FIG. 2 was installed along the inner wall of the tank," 2, Table 3 on page 13 of the same was corrected as follows. 3. Insert the following statement after the statement "6-liquid" on page 15, line 13. "7--Blade" 4. Correct Figure 2 of the drawing as shown in the attached sheet. that's all

Claims (6)

[Claims] (1) A plurality of rotors are placed at appropriate intervals on a shaft that is placed in the liquid in the same tank and rotates at high speed. A multi-stage fine bubble generator characterized by opening the tip of a gas supply pipe inserted into a tank and turning the supplied gas into fine bubbles from a lower rotor through an upper rotor. (2) The multi-stage fine bubble generator according to claim 1, wherein the rotor is a cylindrical body with an open bottom and a closed top. (3) The multi-stage fine bubble generator according to claim 1, wherein the rotor is a cylindrical body with both upper and lower ends closed. (4) Multi-stage micro-bubble generation according to claim 1, characterized in that longitudinal stripes are provided in a band shape on a part of the outer circumferential side of the rotor at equal intervals radially with respect to the central axis. Device. (5) The multi-stage fine bubble generating device according to claim 1, wherein the gas is supplied to the lower center of the lowermost rotor by a gas supply device. (6) Blades are provided radially on the lower surface of the lowest rotor, and below the blades, a flat plate or expansion tube having an outer diameter of 1.1 to 1.5 times the diameter of the rotor is provided at the upper end. 2. The multi-stage fine bubble generating device according to claim 1, wherein the gas is sucked and supplied from a gas suction pipe having an upward open end.