JPH0568810A - Equipment for removing bubbles in liquid - Google Patents

Abstract

PURPOSE:To collect and remove bubbles by moving liquid in a vessel and applying large electric force to the bubbles moved when removing bubbles in liquid in the gravity-free environment or the in the micro gravity environment. CONSTITUTION:In the outer circumference of a vessel 1 holding liquid 2 including bubbles 3 is arranged an electrohydrodynamics pump element 12 for moving the liquid 2 in the vessel 1 upward. In the upper part of the vessel 1 is installed a mesh-shaped electrode 8 formed by connecting wires 4, 5 to an AC power source 9. When the bubbles 3 in the liquid 2 moved by the electrohydrodynamics pump element 2 are conveyed to the mesh-shaped electrode 8, they are collected in the mesh central part with weak electric field by the mesh-shaped electrode 8. The bubbles 3 come into contact with gas in outside space 15 at top of the vessel to remove them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for removing bubbles in a liquid under a zero-gravity environment or a microgravity environment for use in material experiments in space.

[0002]

2. Description of the Related Art Opportunities to use liquids in outer space are expected to increase with the progress of space development, and accompanying this, bubbles contained in liquids used in outer space. In order to bring about disturbance of experimental conditions and deterioration of the performance of the liquid system, it is essential to develop a technology to efficiently separate and remove the bubbles contained in the liquid.

From this point of view, as a basic technique necessary for space development, a device for moving and removing bubbles in a liquid under zero gravity or under microgravity has been developed.

FIG. 5 shows a conventional bubble removing device.
A ring-shaped (lattice-shaped) electrode c is installed concentrically in a container a in which the liquid b is present, and a straight rod electrode d is arranged at the center of the ring-shaped electrode c so that both electrodes c and d are high. Potential difference v
Is applied to make it possible to generate an unequal electric field which becomes weaker from the straight rod electrode d toward the ring electrode c.
By filling with the phase, the bubble e group in the unequal electric field is moved by the electrostatic force F toward the weak direction of the electric field. The electrostatic force F acting on the bubble (polarized particle) e is represented by F = 2πr ³ ε ₀ ε ₁ (ε ₂ −ε ₁ ) / (2ε ₁ + ε ₂ ) · gradE ² (1).

Here, r: radius of bubble e ε ₀ : vacuum permittivity ε ₁ : relative permittivity of liquid b ε ₂ : relative permittivity of bubble e E: non-uniform electric field ε ₂ −ε ₁ Since <0, the direction of the electrostatic force F is always opposite to the direction of gradE ² , that is, the direction in which the slope of the square of the electric field decreases, and the magnitude thereof is proportional to gradE ² .

Next, conventionally, by receiving the electrostatic force F according to the above equation (1) from the straight rod electrode d toward the ring electrode c, the bubbles gathered outside the ring electrode c. Is removed by a gas permeable membrane arranged outside the ring-shaped electrode c and a decompression device. That is, as schematically shown in FIG. 6, for example, a gas-permeable film f having a mesh-like hole in Teflon and having a property of not allowing liquid to pass but only air bubbles is provided so as to surround the ring electrode c, A gas chamber g is provided outside the gas permeable membrane f, and a decompression device h is provided in the gas chamber g.
It is known that the gas chamber g is evacuated by means of the above method, and the bubble e is sucked into the gas chamber g through the gas permeable membrane f due to the pressure difference, and the bubble e is removed from the gas chamber g to the outside of the container a (hydraulic pressure). And air pressure Vol.20 No.7 1989
Month).

[0007]

However, in the above-described conventional bubble removing device, (i) after moving the bubble e in the liquid b, the gas permeable film f is used to discharge the bubble e out of the container a. The gas permeable membrane f
Since the liquid b cannot permeate and only the bubbles e can permeate, the diameter of the pores is small and the exhaust efficiency is poor. (Ii) Large bubbles cannot be removed. (Iii) Move the bubbles e. Since there is no function to move the liquid b after being made to move, residual bubbles may be re-mixed in the liquid, and (iv) the electric field gradient is small, so that the force acting on the bubbles e is small. There's a problem.

Therefore, according to the present invention, when the bubbles existing in the liquid are moved, the bubbles can be discharged by contacting with the gas without using the gas permeable membrane, and the electric field gradient is increased to enhance the discharging effect. Also, it is intended to enable the removal of large bubbles and also the movement of liquid.

[0009]

In order to solve the above-mentioned problems, the present invention provides a mesh electrode connected to a power source, which is horizontally arranged along the liquid surface in the upper part of a container in which a liquid exists. An electrohydrodynamic pump element is provided outside the container, in which three or more multi-phase AC electrodes connected to a three-phase or more multi-phase AC power supply are arranged in parallel and spirally wound. Further, a circulation line for returning the liquid at the top to the bottom is provided in the container so that the liquid after removing the bubbles can be circulated.

[0010]

By applying the multi-phase AC electrodes of three or more phases, the liquid in the container is moved by the electrohydrodynamic effect due to the unequal traveling wave electric field generated in the container, and the bubbles in the liquid also form a mesh. It is moved towards the electrodes. The bubbles carried to the mesh electrode are pushed to the center of the mesh electrode where the electric field is weak. At this time, the mesh electrode is
Since the gradient of the electric field is large, the force acting on the bubbles is large,
Therefore, the bubbles are easily collected in the central portion of the mesh electrode. The collected bubbles are pushed out to the external space by a force proportional to the lines of electric force generated in the external space, and are discharged by coming into contact with the gas in the external space. If the circulation line is provided, the liquid moved to the mesh-shaped electrode together with the bubbles can be returned to the bottom of the container, so that the bubbles can be prevented from being remixed in the liquid after the bubbles are separated.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show one embodiment of the present invention, in which a core portion 6 is made of an insulating material at the upper end portion of a container 1 containing a liquid (for example, silicon oil) 2 in which bubbles 3 are present. 7
The mesh-shaped electrode 8 formed by weaving the electric wires 4 and 5 covered with the above in a plain weave shape is arranged in a horizontal state, and the electric wires 4 and 5 are connected to an AC power source 9 to connect between the electric wires 4 and 5. The lines of electric force 10 are generated.

On the outer peripheral portion of the container 1, a set of three electric wires (vinyl electric wires) 11a, 11b, 11c formed by covering the core portion with an insulating material from the lower end to the upper end is used as an electrode. The electrohydrodynamic pump element 12 is configured by closely winding in a spiral shape with each of the electric wires 11a, 11b, 1 in the electrohydrodynamic pump element 12.
1c is connected to a three-phase AC power supply 13, and the three-phase AC power supply 13
By applying a voltage to each of the electric wires 11a, 11b, and 11c, an unequal traveling wave electric field is generated in the inner peripheral portion and the outer peripheral portion of the electrohydrodynamic pump element 12, and the electrohydrodynamic effect due to the unequal traveling wave electric field is generated. A force for moving the liquid 2 contained in the container 1 from the lower part to the upper part of the container 1 is applied.

The applicant of the present invention has already applied for a patent for the electrohydrodynamic pump element itself (Japanese Patent Application No. Hei 3).
-89416).

Between the top and bottom of the container 1,
A pipe 14 is provided as a circulation line for circulating the liquid 2 moved upward.

When a liquid 2 containing bubbles 3 is put in the container 1, the liquid 2 and the bubbles 3 in the container 1 are unequal traveling waves generated by the electrohydrodynamic pump element 12 on the outer peripheral portion of the container 1. Due to the electrohydrodynamic effect of the electric field, it is carried toward the mesh-shaped electrode 8 at the upper position, and at the same time, it is moved toward the center as it goes upward.

Liquid 2 carried to the position of mesh electrode 8
The bubble 3 in the inside receives the interaction force between the polarized electric charge of the bubble and the electric field due to the electric field along the tangent line of the electric force line 10 generated between the electric wires 4 and 5 of the mesh-shaped electrode 8.
According to the equation (1), the electric field is collected in the weak direction, that is, in the central portion of the mesh electrode 8 (position A in FIG. 2). or,
As shown in FIG. 1B, the electric wires 4, 5 of the mesh electrode 8
Since the lines of electric force 10 generated between them also exist in the external space 15, the bubbles 3 collected in the central portion of the mesh electrode 8 are formed.
Are extruded into the external space 15. 16 is a liquid surface.
At this time, since the mesh-shaped electrode 8 is woven by the electric wire 4 corresponding to the warp thread and the electric wire 5 corresponding to the weft thread, the gradient of the electric field is large (that is, gradE ^{2 in the} above formula (1) is large). Since the force acting on the bubbles 3 is large, the action of separating and collecting the bubbles can be surely performed.

Bubbles 3 collected by the mesh electrode 8
Contact the gas in the external space 15 at the top of the container 1,
Is naturally discharged in the direction of arrow B.

Since the liquid 2 in which the bubbles 3 are separated during the movement can be circulated and moved to the bottom of the container 1 through the circulation pipe 14,
There is no risk that the separated bubbles 3 will be mixed again in the liquid.
At this time, if the position above the circulation pipe 14 is near the wall of the container 1 having few bubbles 3, the effect can be further enhanced.

In the above embodiment, the mesh electrode 8
Although the AC power source 9 is used as the power source of the above, the wires 4 and 5 may be connected to the DC power source 15 as shown in FIG. 4, and the mesh size of the mesh electrode 8 is arbitrary. In addition, it is possible to easily remove bubbles having a large diameter, and the electrohydrodynamic pump element 12 for liquid transfer has a three-phase AC electrode.
Although the multi-phase AC electrode having more than one phase may be used, and the mesh-shaped electrode 8 has a structure in which the electric wires 4 and 5 are woven in a plain weave shape, the electric wires 4 and 5 arranged in parallel are simply superposed in a right angle direction. It goes without saying that the configuration is the same and that various changes can be made without departing from the scope of the invention.

[0021]

As described above, according to the apparatus for removing bubbles in a liquid of the present invention, three-phase or multi-phase AC electrodes for liquid transfer are arranged in parallel on the outer peripheral portion of a container containing a liquid containing bubbles. Further, the electrohydrodynamic pump element is formed by densely winding it in a spiral shape, and liquid and bubbles moved by an unequal electric field generated in the electrohydrodynamic pump element are separated and collected in a weak electric field direction. Since the mesh electrode is arranged on the upper part of the container, when the liquid in the container and the bubbles in the liquid are carried to the mesh electrode by the electrohydrodynamic effect, the electric field of the mesh electrode is bubbled to the central part where the electric field is weak. The air bubbles are collected, and the collected air bubbles are separated and discharged by contacting the outside gas. Therefore, it is possible to easily remove the air bubbles without passing through the gas permeable membrane due to the pressure difference as in the conventional method, and the mesh Since the electrode has a large electric field gradient, the force acting on the bubbles is large, the discharge effect is large, and the electrostatic field causes no power consumption, and the circulation pipe is installed in the container to move the electrode. By circulating the generated liquid, there is no risk that the separated bubbles will be re-mixed in the liquid, and the mesh-shaped electrode can remove bubbles with a large diameter in the container by changing the mesh openings. There is also an effect that it can be achieved.

[Brief description of drawings]

FIG. 1 shows an outline of an embodiment of an apparatus for removing bubbles in liquid of the present invention, (a) is a side view, and (b) is an enlarged perspective view of a part of a mesh electrode.

FIG. 2 is a schematic view showing an enlarged portion of a mesh electrode.

FIG. 3 is a cross-sectional view of an electric wire forming a mesh electrode.

FIG. 4 is a schematic view of a mesh electrode showing another example of the present invention.

FIG. 5 is a diagram showing an outline of a conventional bubble removing device.

FIG. 6 is a sectional view showing a part of a conventional bubble removing mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 container 2 liquid 3 bubble 4,5 electric wire 6 core part 7 insulating material 8 mesh electrode 9 AC power supply 11a, 11b, 11c electric wire (three-phase AC electrode) 12 electrohydrodynamic pump element 13 three-phase AC power supply 14 circulation pipe (Circulation line) 15 External space 17 DC power supply

Claims (2)

[Claims] 1. A mesh-shaped electrode formed by arranging electric wires each having a core portion coated with an insulating material in a woven pattern is horizontally arranged above a container in which a liquid is present, and the mesh-shaped electrode Is connected to an AC or DC power supply, and an electrohydrodynamic pump element is formed by arranging three or more multiphase AC electrodes connected to a three-phase or more polyphase AC power supply in parallel on the outer peripheral portion of the container and spirally winding the electrodes. A device for removing bubbles in a liquid, which is characterized by being provided. 2. The apparatus for removing bubbles in liquid according to claim 1, wherein a circulation line for circulating the liquid in the container from the upper position to the bottom is provided on the side of the container.