JPH08131710A - Apparatus for transferring air bubble in liquid utilizing magnetic field - Google Patents

Abstract

PURPOSE: To move air bubbles in a liq. in the cosmic space where buoyancy is not present by an apparatus wherein a pair of magnetic poles forming a gradient magnetic field are provided in the liq. contg. the air bubbles therein or on the outside thereof and moving the air bubbles in the direction of the gradient magnetic field by utilizing the gradient magnetic field. CONSTITUTION: A pair of magnetic poles 4 and 4 forming a gradient magnetic field are provided in a liq. 2 contg. air bubbles 3 therein or on the outside thereof and a force of the magnetic field is applied on the air bubbles by utilizing the gradient magnetic field based on the difference in vol. susceptibilities of the liq. 2 and gas in the air bubbles 3 to move the air bubbles in the direction of the gradient magnetic field. In this case, the magnetic poles 4 and 4 are bound each other with a soft iron supporting body 15 and when the distance (t) between the magnetic poles is changed along gradient faces 4a and 4b of the magnetic poles 4 and 4, a large gradient magnetic field is generated between both magnetic poles. Therefore, it can be used for removal of mixed air bubbles in a carrying pipe, removal of air bubbles on the surface of electrodes of a battery, removal of air bubbles in the electrophoresis layer of an electrophoresis apparatus, removal of air bubbles in a cooling water and removal of air bubbles in a fuel tank and it is especially effective under microforce of gravity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device capable of moving and defoaming bubbles in a liquid under microgravity without using a mechanical device such as a motor.

[0002]

2. Description of the Related Art Gravity exists on the earth, and bubbles in liquid move upward due to buoyancy. However, at present, there is no suitable means for moving the gas (bubbles) in the liquid while the liquid and the gas remain mixed under zero gravity, except for applying vibration.

[0003]

In microgravity such as outer space, since buoyancy does not exist, bubbles and liquid remain mixed and the presence of bubbles becomes a big problem. For example, in the experiment of the Space Shuttle "Colombia" in which Mr. Mukai et al. Got in in 1994, there was a problem in that the cooling water of the electrophoresis apparatus had a bubble, so that the apparatus could not be operated. Further, it is known that bubbles also entered the electrophoresis layer during the experiment using the electrophoresis apparatus, which caused problems such as malfunction of the apparatus (Newton, October, 1994) No., pp. 59-60, Kyoikusha). Furthermore, when a battery is used in space, the gas generated on the electrode surface remains and the electrode reaction is suppressed (Water Electrolysis Under Microgravity Cond).
ition by Parabolic Flight, H.Kaneko et al. Electr
ochimicaActa 38, 729-733, 1993). As described above, under the microgravity, the control of the bubbles in the liquid is an important problem, and at present, there is no appropriate means for removing the bubbles.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies on a method for controlling bubbles in a liquid under microgravity, and as a result, focused on the difference in volume susceptibility between a liquid and a gas (bubbles). By placing this liquid in a predetermined gradient magnetic field, it was found that it was possible to control the movement of bubbles and the like,
The present invention has been accomplished based on this finding. That is, the present invention provides (1) a pair of magnetic poles for forming a gradient magnetic field in or outside a liquid having bubbles therein, and the gradient magnetic field is determined by a difference in volume susceptibility between the liquid and the gas in the bubbles. A bubble moving device characterized in that a magnetic field force is applied to the bubble by utilizing the above, and the bubble is moved in the direction of the gradient magnetic field. (2) The direction in which the liquid is diamagnetic and the bubble is moved (1) A bubble moving device in a liquid using a magnetic field according to (1), wherein the liquid is paramagnetic and moves in a direction in which bubbles move. (1) The apparatus for moving bubbles in a liquid using a magnetic field according to the above (1), and (4) forming a gradient magnetic field for a liquid having bubbles inside. And the volume susceptibility of gas in liquid and gas bubbles Accordingly, a magnetic field force is applied to the bubble by using the gradient magnetic field, there is provided a bubble moving method characterized by moving the bubbles in a predetermined direction. The present invention utilizes the fact that the volume susceptibility of bubbles in a liquid is largely different from that of a liquid, and that a large magnetic field force acts on such bubbles in a gradient magnetic field. Just as the physical quantity per unit volume perceived by the gravitational field is the density, the physical quantity perceived by the magnetic field is the volume susceptibility. Each substance has its own volume susceptibility, and most substances are diamagnetic (the sign of the volume susceptibility is negative). Oxygen gas and salts of transition elements are paramagnetic (the volume susceptibility is positive). Just as the density of a liquid differs greatly from that of a gas, the volume susceptibility also differs greatly.

The volume magnetic susceptibility of water or an organic solvent, which is a diamagnetic substance, is negative and of the order of 10 ^-7 . For example, the volume magnetic susceptibility of pure water at 20 ° C. is -0.720 × 10 ^-6 ( CGS
Unit). Most gases are also diamagnetic, and their volume susceptibilities are negative and on the order of 10 ^-10 at room temperature (Chemical Handbook, Basics II, 2nd revised edition, P.1233, 1236, Maruzen). As an exception, oxygen gas is paramagnetic, and its volume susceptibility is + 1.5 × 10 ⁻⁷ . As described above, the volume susceptibility per 1 mL is characterized in that a liquid is greatly different from a gas. Particular restriction on the combination of the gas in the bubbles of applying the present invention method (volume magnetic susceptibility chi) and liquid (volume magnetic susceptibility chi ₀₎ is not, What is may, but for example, as follows Is raised. (A) Paramagnetic gas and diamagnetic liquid For example, air and pure water (χ−χ ₀ = 7.5 × 10 ⁻⁷ ) Oxygen and pure water (χ−χ ₀ = 8.7 × 10 ⁻⁷ ) (b ) Paramagnetic gas and paramagnetic liquid For example, air and water in which 0.1 g of Mohr's salt is dissolved per mL (χ−χ ₀ = −2.51 × 10 ⁻⁶ ) (c) Diamagnetic gas and diamagnetic liquid , Nitrogen gas and pure water (χ−χ ₀ = 7.2 × 10 ⁻⁷ ) (d) Diamagnetic gas and paramagnetic liquid For example, nitrogen gas and Mohr's salt solution (χ−χ ₀ = −2.5)
4 × 10 ^-6 )

In general, liquids are often diamagnetic, but when paramagnetic ions are dissolved in such liquids, they become paramagnetic. The present invention can be applied to such a device. For example, paramagnetic ions Fe ²⁺ , Fe ³⁺ , Cu ²⁺
When the metal ions are added, the aqueous solution becomes paramagnetic, the volume susceptibility becomes positive, and the difference χ−χ ₀ from the paramagnetic or diamagnetic gas becomes negative as in (b) and (d) above. be able to. Liquid oxygen is paramagnetic and volume susceptibility χ ₀ is about 3 × 10
^-4 is very large, and the present invention is particularly effective. The present invention makes use of the fact that a force such as buoyancy acts on bubbles by a gradient magnetic field when the physical quantity and volume susceptibility sensed by a magnetic field differ greatly between a liquid and a gas. In the present invention, the larger the product of the magnetic field strength and the magnetic field gradient and the larger the difference between the volume susceptibility of the liquid and the bubble, the greater the force of the acting magnetic field, and the greater the effect of the present invention. In the present invention, the product of the magnetic field strength and the magnetic field gradient is preferably as large as possible. In the case of a permanent magnet, a gap between magnetic poles of 1 cm can be about 150 KG ² / cm. The product of the magnetic field strength and the magnetic field gradient is usually 50 KG ² / c
m, but can be made smaller under microgravity. In the device of the present invention, the larger the magnetic field gradient of the magnet, the better, and there is no particular limitation.
KG ² / cm or more, preferably 150 kg ² / cm or more. If the magnetic field gradient is too small, bubbles may not move, for example, when the viscosity of the liquid is large or when the surface tension is large.

In the bubble moving device of the present invention, the volume Vm
L, when bubbles of the volume magnetic susceptibility chi is present in the liquid volume magnetic susceptibility chi _o, with field gradient (δH / δX), acting in the X-axis direction in bubbles in the gradient magnetic field of the magnetic field intensity (H) Power Is given by the following equation. F = V × (χ−χ _o ) × H × (δH / δX) Equation (1) As described above, since the volume susceptibility of diamagnetic gas is much smaller than that of liquid, the gas of Equation (1) The volume susceptibility can be omitted. _{F = -V × χ o × H} × (δH / δX) Formula (2) This equation represents the force bubbles undergoes X-axis direction, when the liquid volume magnetic susceptibility of the diamagnetic material is negative, a magnetic field is It shows that the force acts in the increasing direction. When the liquid is paramagnetic such as liquid oxygen, a force acts on the gas bubbles in the direction in which the magnetic field decreases. Water is diamagnetic, but when used as cooling water, it is also possible to control the volume susceptibility to a positive value by dissolving paramagnetic ions.

The bubble removing method and bubble moving apparatus of the present invention removes bubbles in various aqueous solutions such as pure water and an aqueous solution in which a salt of a paramagnetic transition element is dissolved, and various organic solvents such as alcohol, benzene and toluene. Applied to. Specifically, removal of air bubbles mixed in the transport pipe, removal of air bubbles on the electrode surface of the battery, removal of the migration layer of the electrophoresis device, removal of the bubbles in the cooling water, removal of the bubbles in the fuel tank (for rocket fuel Removal of gas O _{2 in} liquid oxygen). These applications can be performed in a place where the earth's gravity acts, but it is more preferable to use them under microgravity.

[0009]

Next, the present invention will be described in more detail with reference to examples. Embodiment 1 The present invention will be described with reference to an embodiment shown in FIG.
FIG. 4 is an explanatory view of a device for moving bubbles in a liquid using a magnetic field according to the present invention. 1 is a container or pipe in which the liquid 2 exists, and bubbles 3 exist in the liquid. Reference numerals 4 and 4 denote a pair of magnetic poles of a permanent magnet for generating a gradient magnetic field m in the space where the bubble 3 exists. The shape of the magnetic pole is designed such that the product of the magnetic field strength and the magnetic field gradient is maximized. An electromagnet or the like may be used instead of a permanent magnet to generate a magnetic field. In general, the magnetic poles 4, 4 are connected to each other by a soft iron support 15. 4a and 4a are gradient surfaces of the magnetic poles 4 and 4,
When the distance t between the magnetic poles changes along this plane, a large gradient magnetic field is generated between the magnetic poles. When the bubble moving device of the present invention is used, when the magnet is installed outside the container, the material of the container containing the target liquid, the pipe, and the like may be any material that does not block or obstruct the magnetic force such as iron. For example, plastic, glass, aluminum, copper, etc. are used. FIG. 2 is an explanatory diagram of the gradient magnetic field m formed by the bubble moving device of FIG. The horizontal axis is the X-axis of the position coordinates, which corresponds to the X-axis shown in FIG. 1, where a indicates the position of the left edge of the magnetic pole 4 in FIG. 1 and 0 indicates the position of the center of gravity of the bubble 3. The vertical axis represents the magnetic field strength (H), and the magnetic field strength increases along the direction of arrow 5. When such a gradient magnetic field m is applied, when the liquid is a diamagnetic substance, an arrow 5
A magnetic field force acts on the bubble in the direction of, and the bubble can be moved in the arrow direction 5. For example, 1 mL in diamagnetic pure water
If there are bubbles of diamagnetic gas such as nitrogen gas,
When the magnetic field force acting on the bubble is expressed by the equation (2), when the magnetic field strength H is 15 kG and the magnetic field gradient is 10 kG / cm, F = 0.720 × 10 ⁻⁶ × 1.5 × 10 ⁴ × 10 × 10
³ = 108 dynes. Buoyancy acting on 1 mL of bubbles in the gravitational field, which is small compared to 980 dynes, but it is considered to work effectively in outer space where gravity does not exist.

Example 2 Next, a paramagnetic salt was previously dissolved in the liquid 2 of Example 1,
The test was performed when the sign and value of the volume susceptibility were significantly changed. Mall salt (FeSO ₄ (NH
₄ ) When 0.1 g of ₂ SO ₄ .6H ₂ O) is dissolved, the volume susceptibility of the solution is (3.26-0.72) × 10 ⁻⁶ ,
Indicates a positive value. Incidentally, the magnetic susceptibility per 1 g of the Mohr salt at room temperature is 32.6 × 10 ⁻⁶ . 1 mL in this solution
In case of the presence of bubbles, the magnetic field strength H is 15 kG in FIG.
Applying a magnetic field when the magnetic field gradient is 10 kG / cm, F = 2.54 × 10 ⁻⁶ × 1.5 × 10 ⁴ × 10 × 10 ³
= 381 dynes acts, and the bubble 3 can be moved in the direction of the arrow 6 where the magnetic field intensity decreases.

Example 3 A test was conducted using the experimental apparatus shown in FIG. Alumina pellets 8 containing a platinum catalyst (0.5%
Alumina pellets, manufactured by NE Chemcat Corporation
When 1% aqueous hydrogen peroxide solution 9 was poured, oxygen gas bubbles generated on the surface of the alumina pellets moved upward along arrow 10. As the gradient magnetic field in this case, as shown in FIG. 3B, a magnetic field (H) whose magnetic field strength (H) increases along the X-axis direction where the surface of the alumina pellet 8 is 0, which is the direction of arrow 10. The amount of oxygen gas generated when b) was applied and when it was not applied was measured. The magnetic field strength is 12 at the position of the alumina pellet.
kG and a magnetic field gradient of 3 kG / cm. The magnet is an electromagnet (I
DX ISM-130WV) was used. In FIG. 3, reference numeral 12 denotes the shape of the pole piece of the electromagnet. When the above gradient magnetic field was applied, the amount of generated oxygen gas increased by 3% as compared with the case where no gradient magnetic field was applied. In this reaction, removal of oxygen gas from the catalyst surface is the rate-determining step of the reaction. On the earth, buoyancy causes oxygen gas to be removed from the catalyst surface in the direction of arrow 10, but this result indicates that the magnetic field also contributed to oxygen gas removal. Further, when the position of the test tube is shifted and a gradient magnetic field (b) is applied along the X axis so that the magnetic field intensity decreases in the opposite direction, the amount of generated oxygen gas is reduced by 3% as compared with the case without the magnetic field. did. This result shows that the gradient magnetic field acted on the oxygen gas in the direction of the arrow 11 to suppress the removal of bubbles from the catalyst surface. These results indicate that the magnetic field effectively affects the transport of bubbles in the liquid.

Embodiment 4 Although an electromagnet was used in Embodiment 3, a superconducting magnet (SMI type, manufactured by Oxford) was used in this embodiment. As shown in FIG. 4A, the location 13 where the magnetic field is generated is cylindrical and horizontal. As shown in FIG. 4B, the magnetic field intensity reaches a maximum of 60 KG at the center 0 point of the cylinder and decreases outward at a gradient of 10 KG / cm. The L-shaped glass tube 14 whose bottom was sealed was inserted into the magnetic field 13 at an angle of about 20 ° from the horizontal as shown in FIG. When a 1% aqueous peroxide solution 9 was poured into an alumina pellet 8 containing a platinum catalyst, which was placed around the zero point, a bubble 15 of oxygen gas was generated.
Remained around 0. At this time, the force acting on 1 mL of oxygen gas in the vicinity of the 0 point is F = (1.5 + 7.2) × 10 ⁻⁷ × 6 × 10 ⁴ × 10 ^{4 according to the} equation (2).
= 522 dynes / mL, acting in the direction of arrow 16. When the magnetic field was turned off, the bubble 15 immediately moved in the direction of arrow 17.
These results indicate that the magnetic field effectively affects the transport of bubbles in the liquid.

Embodiment 5 The place 13 where the magnetic field of the superconducting magnet generates is cylindrical and horizontal. As shown in FIG. 5A, a U-shaped glass tube 20 having an inner diameter of 2 cm and filled with pure water 21 was arranged. As shown in FIG. 5 (B), the magnetic field strength is 1 at the center 0 point.
It reaches the maximum of 00KG and decreases with a gradient of 10KG / cm to the left and right. When air bubbles 22 were present in the pure water 21, it was observed that the air bubbles 22 moved to the center where the magnetic field was strong, and the water 21 was finally separated at the center by the air 23. When pure water was converted to a paramagnetic copper sulfate aqueous solution, it was observed that air bubbles were pushed out to the outside where the magnetic field was weak, contrary to before.

[0014]

As described above, the apparatus for moving bubbles in a liquid using a magnetic field according to the present invention moves bubbles generated in the liquid by a completely different principle from those conventionally used. This is particularly effective for the movement of bubbles in liquid in space where buoyancy does not exist. The present invention has the advantage that the use of a rare earth permanent magnet does not require a power source, is light, portable, can be used anywhere, and is easy to use. Further, according to this bubble moving device, since a motor or the like is not required to drive the bubble moving device, a fire,
It has an excellent effect that a highly safe system can be assembled without fear of explosion.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of one embodiment of a bubble moving device of the present invention.

2 is a graph of a gradient magnetic field m of the bubble moving device of FIG.

FIG. 3A is an explanatory diagram showing an example of magnetic field transport of bubbles in a liquid according to another embodiment of the present invention. (B) It is a graph of the gradient magnetic field m in (A).

FIG. 4A is an explanatory diagram showing an example of magnetic field movement of bubbles in a liquid according to another embodiment of the present invention. (B) It is a graph of the gradient magnetic field m in (A).

FIG. 5A is an explanatory diagram showing an example of magnetic field movement of bubbles in a liquid according to another embodiment of the present invention. (B) It is a graph of the gradient magnetic field m in (A).

[Explanation of symbols]

 1 container or pipe 2 liquid 3 bubble 4, 4 a pair of permanent magnet magnetic poles 5, 6 bubble moving direction

Front Page Continuation (72) Inventor Hiroyuki Ito 13-chome, Kita-ku, Sapporo, Kita-ku, Hokkaido 13-chome, Keidai Dormitory F-210, Hokkaido University (72) Yukio Kuroda 6-chome, Kita-ku, Kita-ku, Sapporo, Hokkaido Seiunso No. 202

Claims (4)

[Claims] 1. A pair of magnetic poles for forming a gradient magnetic field are provided in or outside a liquid having bubbles therein.
Bubble movement characterized in that a magnetic field force is applied to the bubble using the gradient magnetic field by using a difference in volume susceptibility between a liquid and a gas in the bubble to move the bubble in the direction of the gradient magnetic field. apparatus. 2. The apparatus for moving bubbles in a liquid using a magnetic field according to claim 1, wherein the liquid is diamagnetic and a gradient magnetic field whose magnetic field strength increases in a direction in which bubbles move. 3. The apparatus for moving bubbles in a liquid using a magnetic field according to claim 1, wherein the liquid is paramagnetic and a gradient magnetic field whose magnetic field intensity decreases in a direction in which bubbles move. 4. A gradient magnetic field is formed with respect to the liquid having bubbles therein, and a magnetic field force is applied to the bubbles by using the gradient magnetic field according to a difference in volume susceptibility between the liquid and the gas in the bubbles. A bubble moving method comprising moving bubbles in a predetermined direction.