JPH08131884A - Air flow generator utilizing corona discharge - Google Patents

Abstract

PURPOSE: To realize an air flow generator which utilizes a corona discharge and is capable of suppressing ozone smell and oxidation effect at the time of discharge. CONSTITUTION: Electrodes 2 having sharp pointed tips like needles and electrodes 1 formed to a cylindrical shape are arranged to face each other. The needle-shaped electrodes 2 are set at plus potential and the cylindrical electrodes 2 at minus potential and a DC high voltage to the extent of generating the corona discharge is applied between the respective electrodes so that the flow of the air is generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air flow generator utilizing corona discharge, and more particularly to an air flow generator capable of suppressing ozone odor and oxidation during discharge.

[0002]

2. Description of the Related Art Conventionally, when an air flow or wind is to be generated, an air flow is generated by a mechanical action such as rotating a fan using an electric motor or an engine. With such a mechanical method, noise and vibration are generated, and there is a problem in using in a place where a quiet environment is required.

In order to solve these problems, it has been proposed to generate an air flow by utilizing a high voltage discharge. For example, as described in Japanese Patent Application Laid-Open No. 51-5985, there is a need for air cleaning. It has been put to practical use in electric dust collectors.

FIG. 7 is a circuit diagram for explaining the principle of a conventional dust collector utilizing corona discharge. a is a needle-shaped electrode, and b is, for example, a cylindrical counter electrode, and a negative high-voltage direct current is applied to the needle-shaped electrode a and a positive high-voltage direct current is applied to the counter electrode b. A negative corona discharge is generated between points b, and an air flow is generated in the direction of arrow d.

[0005]

This air flow generator may be used for cooling precision electronic equipment and the like. However, in the conventional structure as described above, when high voltage discharge is performed, discharge occurs. It is not suitable for indoor use due to the accompanying ozone odor. There are also problems such as oxidation.

A technical problem of the present invention is to realize such an air flow generating device using corona discharge which can suppress ozone odor and oxidizing action during discharge, paying attention to such a problem.

[0007]

According to a first aspect of the present invention, a sharp electrode 2 such as a needle and a cylindrical electrode 1 are arranged so as to face each other, and the needle electrode 2 has a positive potential. An air flow generator using corona discharge in which a cylindrical electrode 1 is set to a negative potential and a high DC voltage that causes corona discharge is applied between the electrodes to generate an air flow. is there.

The invention according to claim 2 is the needle electrode 2 according to claim 1.
Is an airflow generation device utilizing corona discharge arranged so as to be located on the center line of the cylindrical electrode 1.

According to a third aspect of the present invention, the cylindrical electrode according to the first or second aspect has a taper shape in which the diameter on the side opposite to the side of the needle-shaped electrode 2 is larger than that on the side of the needle-shaped electrode 2. It is a device.

The invention of claim 4 is from claim 1 to claim 3.
The corona discharge in which the high DC voltage applied between the needle-shaped electrode 2 and the cylindrical electrode 1 described in any one of the above is a voltage in a region before a thin linear corona discharge is generated is used. It is an air flow generator.

The "air flow generator" in the present invention
The term “device” and the like include devices that obtain propulsive force by generating an air flow.

[0012]

According to the first aspect of the present invention, the needle-shaped electrode 2 and the tubular electrode 1 are opposed to each other, and the needle-shaped electrode 2 is at a positive potential and the tubular electrode 1
Is set to a negative potential and a corona discharge is generated, whereby an air flow with little ozone odor during discharge can be obtained. In addition, as the ozone is reduced, the oxidizing action can be suppressed.

By disposing the needle-shaped electrode 2 on the center line of the cylindrical electrode 1 as in claim 2, the discharge distance becomes constant, so that local arc discharge is prevented and the discharge is uniform and stable. The generated air flow can be generated.

By forming the tubular electrode into a tapered shape having a large diameter on the back side as in claim 3, the opening area on the back side of the tubular electrode is increased and the air resistance is reduced, which is more effective. You can make the air flow stronger.

According to a fourth aspect of the present invention, the high DC voltage applied between the needle-shaped electrode 2 and the cylindrical electrode 1 is a voltage in a region before a thin linear corona discharge is generated. Further, it is possible to obtain an air flow with less generation of ozone odor, discharge noise, etc. economically with less power consumption.

[0016]

EXAMPLES Next, practical examples of how the airflow generator utilizing corona discharge according to the present invention is embodied will be described. FIG. 1 is a circuit diagram showing a first embodiment of an airflow generator using corona discharge according to the present invention.

Reference numeral 1 denotes a cylindrical electrode, and a needle-shaped electrode, that is, a sharp electrode 2 is arranged facing the cylindrical electrode 1. Reference numeral 3 is a direct current high voltage power source, the positive side of which is connected to each needle electrode 2 via a resistor 6 and the negative side of which is connected to the cylindrical electrode 1. Each cylindrical electrode 1,
The area 1 is partitioned by the insulating material 5, but it is not essential.

Now, a high DC voltage is applied between the needle electrode 2 and the cylindrical electrode 1 by the DC high voltage power supply 3. At this time, the voltage is set so that corona discharge is generated between the electrodes 2 and 1. As a result, an air flow is generated in the direction of arrow 4 with the corona discharge. In practice, a plurality of pairs of the needle-shaped electrode 2 and the cylindrical electrode 1 are arranged according to the application, and a larger amount of air flow is generated and used.

In this way, a positive potential is applied to the needle-shaped electrode 2,
Further, by applying a negative potential to the cylindrical electrode 1 and applying a high DC voltage, it is possible to effectively suppress the generation of ozone odor during discharge and also suppress the oxidizing action.

Next, the air flow generator used in the experiment of the present invention will be explained and the experimental result will be considered. FIG. 2 is a perspective view of an airflow generator using corona discharge used in the experiment, and FIG. 3 is a front view, a sectional view taken along line AA, and a rear view of the same.

Reference numeral 7 is a square printed circuit board having a side of 70 mm, and square holes are formed in a matrix to form a grid-like portion 7a. It is fixed by soldering.

The needle-shaped electrode 2 made of iron is fixed to the tip of the resistor 6a by soldering vertically to the substrate 7, but the needle-shaped electrode 2 may be directly attached to the substrate 7. Good. The resistor 6a used was 5.1 MΩ.

Reference numeral 8 is a conductive substrate, which is a printed circuit board 7.
And are fixed to each other by a square insulating frame plate 9. The conductive substrate 8 has a diameter of about 9 m.
Make a hole of m, and the length is about 5 m made of stainless steel.
A cylindrical electrode 1 having an inner diameter of 8.5 mm and an inner diameter of 8.5 mm is inserted and fixed by soldering.

At this time, the tip of the needle electrode 2 is the cylindrical electrode 1.
Of the needle electrode 2 and the tip of the needle-shaped electrode 2 is separated from the outer peripheral portion of the cylindrical electrode 1 by about 2 mm in the direction on the center line. The needle electrode 2 and the cylindrical electrode 1
A total of 25 pairs of 5 and 5 pairs were arranged.

In this device, the needle electrode 2 on the resistor 6a side is used as a positive electrode, the cylindrical electrode 1 is used as a negative electrode, and a high DC voltage in the range of about 3500 to 9000 V is applied between the electrodes 2 and 1. In addition, a corona discharge was generated. At that time, an experiment was conducted by delicately adjusting the high DC voltage so as to maintain an optimum corona discharge state between the electrodes 2 and 1.

As a result of carrying out the above-mentioned experiment under the condition that the lighting in the laboratory was dim, corona discharge could be confirmed. Explaining the situation of the discharge at that time, a positive corona film-shaped corona covering the needle electrode 2 from the time when a high DC voltage of about 5000 V was applied between the needle electrode 2 and the cylindrical electrode 1. Was generated in the atmosphere on the surface of the needle tip, and emitted a faint bluish-white light, and an air flow was generated along with the noise of “sir”.

When the voltage was gradually increased to about 7,000 V, the pale white light became stronger and the air flow became faster. At that time, the noise called "sir" became smaller and the pale light became stronger. When the voltage is further increased to about 8000 V, the thin light emitting linear shape (streamer) of the positive corona extends toward the center of the cylindrical electrode 1 as shown in FIG. 4 (1),
Again, the noise of “sir” was heard loudly, and the smell of ozone became stronger.

On the contrary, like the conventional dust collector, the needle-shaped electrode 2
When a negative corona discharge was performed with a negative potential and the cylindrical electrode as a positive potential, a discharge state as shown in FIG. 4 (2) was confirmed. That is, the electric discharge c is generated at the shortest distance between the needle electrode 2 and the cylindrical electrode 1. In this case as well, an air flow was generated, but a strong ozone odor was generated during the experiment.

Next, the shapes of the needle electrode 2 and the cylindrical electrode will be considered. From a number of experiments, in order to use the discharge in an electric field to create a flow of air, it was better to use an unequal electric field. Therefore, in order to form a significant unequal electric field, we first devised a point-to-face electrode structure. However, it has been found that even if the electric field is not uniform, if the discharge gap is not uniform, arc discharge occurs between the point with the shortest gap and the surface, which causes heat generation and abnormal current.

Therefore, in order to satisfy not only the condition of point-to-face but also the condition of uniform discharge gap, a method was devised in which the center of the circle is a point and the surface is a cylinder. As a result, an electrode structure that discharges from a point to a cylinder was formed, and the point became a needle tip, and a structure was formed in which an unequal electric field was formed between the needle tip and the cylinder.

As shown in FIG. 5A, the cylindrical electrode has a tapered shape in which the diameter D of the back portion (opposite to the needle electrode 2) 1h is larger than the diameter d of the needle electrode 2 side. Thus, the opening area on the back 1h side is increased. As a result, the resistance of the air flow passing through the cylindrical electrode 1a is reduced, and the air flow becomes stronger.

As shown in FIG. 5B, the back 1H is
When the outer diameter D of the inscribed circle is a regular hexagon larger than the diameter d on the needle electrode 2 side and is arranged in a honeycomb shape as shown in FIG. 5 (3), there is no useless space that does not contribute to the air flow generation. , Smaller size and larger air flow.

Thus, in terms of eliminating unnecessary space, the back portion 1H can be formed into a regular hexagon without tapering as shown in FIG. 5 (4). In this case, the circle inscribed in the regular hexagon is the diameter d of the cylindrical electrode 1 on the needle electrode 2 side.
It has the same dimensions as. As is clear from FIGS. 2 and 3,
If the back of the cylindrical electrode 1 is a perfect circle, a space between the perfect circles will be a wasteful space that does not contribute to the generation of an air flow, and the size will be large.
If the cells are arranged in a regular hexagonal shape and arranged in a honeycomb shape, no space is wasted and the size can be reduced.

FIG. 6 is a diagram showing voltage-current characteristics,
The specific numerical value and low power consumption were explained. The characteristics of the experimental device were measured and the results were as follows. From this measurement result, the voltage-current characteristics are different between the positive corona and the negative corona in the unequal electric field in the air.

The curve ABCD is the voltage of the positive corona −
The current characteristics, the voltage-current characteristics of the negative corona, the wind speed of the positive corona, and the wind speed of the negative corona are shown. As is apparent from the graph, the negative corona consumes more power when discharging the positive corona and the negative corona at a high DC voltage of about 6.7 KV, but the wind speeds are almost the same.

Then, the voltage is further increased to about 70.
At 00V, the positive corona wind speed exceeds the negative corona wind speed. Therefore, when the positive and negative corona discharges are used to generate an air flow and both are compared, it is possible to generate a high-speed air flow with less power consumption in the positive corona discharge. It became clear.

As described above, the fact that the air flow can be generated with a smaller electric current means that the ionization of gas molecules can be suppressed as much as possible, and the difference in the generation of ozone odor between the positive corona and the negative corona during the experiment. You can judge from what you feel.

In the negative corona, the generation of ozone odor can be easily confirmed at a DC high voltage of 6 KV, and the odor becomes stronger as the DC high voltage rises. But in the positive corona,
The generation of ozone odor is not felt up to 7 KV, and ozone odor is felt near 8 KV and near the start of a thin linear corona discharge.

In the case of the positive corona, the region where the discharge noise is small is clearly distinguishable at about 6.5 KV to 7 KV, and the severe discharge noise is generated at 8 KV. In this case, the distinction between the general membranous corona region, the brush corona region, and the hot corona region cannot be clearly confirmed, but the voltage is 5
At KV or higher, it was possible to observe pale white light that could be inferred to be a film corona generated in the air near the tip of the needle, and pale white light that could be inferred to be a thin linear corona corona when the voltage was increased to 8 KV or higher.

Therefore, according to the measurement results and the experiment, the positive corona discharge is generated in the region of 7 KV or less before the generation of the thin linear corona discharge in the electrode of the needle tip-to-cylindrical unequal electric field like the experimental device. Power consumption is small,
It has become possible to realize an airflow generator that produces less ozone odor, discharge noise, and the like.

[0041]

As described in claim 1, the needle electrode 2 and the tubular electrode 1 are opposed to each other, the needle electrode 2 is set to a positive potential, and the tubular electrode 1 is set to a negative potential, so that corona discharge is generated. With the configuration in which it is generated, it is possible to suppress the ozone odor and the oxidizing action during discharge.

By disposing the needle electrode 2 on the center line of the cylindrical electrode 1 as in claim 2, local arc discharge can be prevented and a uniform and stable air flow can be generated. it can.

According to the third aspect, by making the back side of the cylindrical electrode 1 have a large taper shape, the outflow resistance of air can be reduced and a stronger air flow can be generated.

According to a fourth aspect of the present invention, the high DC voltage applied between the needle electrode 2 and the tubular electrode 1 is set to a voltage in a region before a thin linear corona discharge is generated. It is possible to obtain an air flow with less ozone odor and discharge noise economically with less power consumption.

Therefore, the airflow generator using corona discharge of the present invention can be expected to be applied to various fields such as an air-cooling cooling device, a blower, a ventilation fan, and a propulsion device.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of an airflow generator using corona discharge according to the present invention.

FIG. 2 is a perspective view of an airflow generation device using corona discharge used in an experiment.

3A and 3B are a front view, an AA cross-sectional view, and a rear view of an airflow generator using corona discharge used in an experiment.

FIG. 4A is a diagram illustrating a discharge state when a positive corona discharge according to the present invention is performed, and FIG. 4B is a diagram illustrating a discharge state when a conventional negative corona discharge is performed. Is.

FIG. 5 is a diagram showing various examples of a tubular electrode.

FIG. 6 is a diagram showing measurement results of voltage-current characteristics and wind speed in an experiment of the device of the present invention.

FIG. 7 is a diagram illustrating the principle of corona wind generation in a conventional dust collector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical electrode 1h, 1H Back of cylindrical electrode 2 Needle electrode 3 DC high-voltage power supply 4 Air flow direction 5 Insulation material 6 Resistance 6a Resistor

Claims (4)

[Claims] 1. A sharp electrode 2 such as a needle and a cylindrical electrode 1 are arranged to face each other, and the needle electrode 2 is set to a positive potential and the cylindrical electrode 1 is set to a negative potential, respectively. An air flow generator that uses corona discharge to generate a flow of air by applying a high DC voltage to the extent that corona discharge occurs between the electrodes. 2. The airflow generator using corona discharge according to claim 1, wherein the needle-shaped electrode 2 is arranged so as to be located on the center line of the cylindrical electrode 1. . 3. The air flow utilizing corona discharge according to claim 1, wherein the cylindrical electrode has a taper shape having a larger diameter on the side opposite to the side of the needle electrode 2 side. Generator. 4. The high DC voltage applied between the needle electrode 2 and the tubular electrode 1 is a voltage in a region before a thin linear corona discharge is generated. Item 1
4. An airflow generator using the corona discharge according to claim 3.