JPS5841099B2 - Tiden Reiyuushi Hatsei Souchi - Google Patents

Description

[Detailed Description of the Invention] This invention applies alternating current voltages to planar silent discharge electrodes that face each other at a certain interval and whose phases are shifted so that silent discharge does not occur in both electrodes at the same time. , and applying a voltage between both silent discharge generating electrodes to draw out desired unipolar ions from the side where the silent discharge is occurring to the other side,
The present invention relates to a charged particle generator that enables highly efficient and continuous charging of powder particles by passing the powder particles through the space separating the planar silent discharge electrodes.

Contact charging,
Corona discharge is generated by a method that utilizes frictional charging, or by applying a high DC voltage between a needle-shaped, linear, or blade-shaped electrode and an opposing plate-shaped, cylindrical, or spherical electrode. A method for obtaining unipolarly charged powder by colliding ions generated by this corona discharge with powder particles, and a method for obtaining unipolarly charged powder by colliding ions generated by this corona discharge with powder particles, and for forming alternating electric fields, the ions are arranged parallel to each other and insulated from each other at a certain interval. An alternating electrode having a flat plate or arbitrary polar surface, and one or more small holes or slits installed in the center of each of the one or more small holes or slits provided in each of the alternating electrodes to be insulated from the alternating electrode. It has a plurality of third electrodes for discharge, an AC power source for applying an alternating voltage to the alternating electrode, and a direct current or alternating current power source for applying a direct current or alternating voltage between the third electrode and the alternating electrode. There are particle charging devices and the like that are characterized by this.

Regarding these methods, the method using contact charging is
A major drawback is that it is difficult to clearly determine the amount of charge that the powder is charged with, and therefore, it is technically difficult to control the amount of charge.

Next, in methods that utilize corona discharge, there is a clear quantitative relationship in which the amount of saturation charge obtained by powder particles is proportional to the square of the particle size and the electric field strength in the charged region. Driven by Coulomb force toward the electrode, highly charged particles adhere to the opposing electrode,
A major drawback is the inability to extract the most highly charged particles in the required space.

Next, in a device that charges particles by extracting ions generated by a spark discharge in holes drilled on opposing surfaces into the space separating the opposing electrodes using an alternating current voltage applied between the opposing electrodes, the ions are drawn between the pores and the discharge electrode. Since the discharge that occurs between the
Furthermore, in the space through which the particles pass, there is always a flow of powder as the particles pass, and the resulting powder adheres to the entire surface of the electrode, especially around the pores and the tip of the discharge electrode. The major drawback is that the discharge voltage increases significantly, making it difficult to operate continuously for a long period of time.

Furthermore, in this method, since there is no insulating material between the pores and the discharge electrode, it is completely impossible to charge the conductive powder.

As described above, this invention solves all the drawbacks of conventional particle charging devices and is necessary for electrodynamic powder control devices for dust collection, classification, transportation, electrostatic coating, electrostatic flocking, etc. A new method that can generate highly concentrated solid or liquid particles with a large amount of unipolar charge and supply them accurately and in large quantities to the required area.
Furthermore, the present invention provides a particle charging device that can carry out the above operations with extremely high efficiency.

The present invention provides a planar ion generating electrode in which a pair of electrodes are provided separated by a solid insulator, and at least one of the electrodes is arranged in parallel as a group of linear electrodes, and the planar ion generating electrode is placed opposite to each other. An alternating current voltage is applied between each of the pair of electrodes to generate a silent discharge in the charged space formed by the electrode and the planar ion generating electrode. means for shifting with respect to time, and a voltage between the planar ion generating electrodes such that the planar ion generating electrode generating silent discharge always has the same polarity potential difference with respect to the other planar ion generating electrode. A charging current generator is characterized in that it comprises means for applying .

The present invention produces a silent discharge by applying an alternating current voltage to the planar ion generating electrodes, and also allows the planar ion generating electrodes to face each other by mutually shifting the effective application times of the alternating voltages. The electrodes alternately perform silent discharge to generate positive and negative ions on the surface of the planar ion generating electrode, and the planar ion generating electrode that generated the positive and negative ions is always connected to the other ion generating electrode. By having a potential difference of the same polarity, only one of the positive and negative ions generated in the planar ion generating electrode can be drawn out into the charging space at any time, and the powder passing through the charging space can be charged with high efficiency. I can do it.

Next, a construction method and embodiments of a particle charging device according to the present invention will be explained with reference to the drawings.

FIG. 1 is a perspective view showing the structure of a planar silent discharge electrode used in the present invention.

That is, the planar silent discharge electrode used in the present invention has parallel linear electrodes 1 buried in a shallow part of the surface of an insulating layer 1.
-1°1-2 exists.

Every other parallel line electrode is connected in the same phase, and a high alternating current voltage is applied to these electrodes by a power source 6, as shown in the sectional view of FIG.

As a result, as shown in 1-1 and 1-2 between the electrodes 1-1 and 1-2, lines of electric force are generated in the vicinity of the surface of the electrodes, which are convexly curved outward when viewed from the surface of the electrodes.

The density of the electric lines of force is the electric field strength on the surface of the planar silent electrode, and when the electric field strength becomes higher than the spark voltage of the gas existing in the vicinity, the electric field strength between the electrodes 1-1 and 1-2 A silent discharge occurs in between.

Regarding the situation of silent discharge generation, the situation is exactly the same for the electrode E-2 opposite to one electrode E-1 in the above configuration.
Power for electrode E-2 is supplied by transformer 7 as shown in FIG.

As shown in the figure, these silent discharge electrodes E-1 and E-2 are placed opposite each other with a space 20 in between.

Next, reference numeral 81 in FIG. 3 shows the waveform of the AC voltage applied between each linear electrode of the planar silent discharge electrode.

That is, it is well known regarding silent discharge that silent discharge occurs only at time 22 and time 24 in one cycle extending from time 21 to time 24 at 81 in FIG.

Therefore, in the electrode E1, at time 22 and time 24, high-frequency silent discharge with a frequency of several tens of kilocycles to several megacycles exists between the linear electrodes 1-1 and 1-2 between each electrode. become.

In this case, the frequency of the voltage applied by the power source 6 is
Usually, it is about 10 cycles to 1000 cycles.

Therefore, at time 22 and time 24, strong ionization occurs near the surfaces 1-1 and 2 of the planar silent discharge electrode, and at this time there are many electrons and positive and negative ions, creating a so-called plasma-like space. is formed here.

Therefore, when a DC potential difference exists between electrode E-1 and electrode E-2, electrodes E-1 and E-2 are
Unipolar ions of 10 or - are selectively drawn toward the space 20 by the potential difference that exists between them.

Next, S2 in FIG. 3 shows the waveform of the AC voltage applied to the linear electrodes 2-1 and 2-2 buried inside the electrode E-2.

That is, the AC voltage applied between the linear electrodes embedded in the electrode E-2 has the same waveform as the AC voltage applied to the linear electrode embedded in the electrode E-1, and the phase is 1/1. 4
A voltage delayed by a period is applied.

In this case, as is clear from the figure, the electrode E
At time 22 when silent discharge is occurring on the surface of electrode E-1, there is no silent discharge on the surface of electrode E-2, and at time 22 when silent discharge is not occurring on the surface of electrode E-1, A silent discharge occurs on the surface of the electrode E-2, and the same relationship will be stably maintained thereafter.

Therefore, what is shown next at R in FIG. 3 is the potential of the electrode E1 with respect to the ground point, and the potential in FIG. It is configured to apply a voltage.

That is, at time 21, electrode E-1 has a positive potential with respect to the ground point, and electrode E-2 has a negative potential with respect to the ground point, so there is a relative relationship between electrodes E-1 and E-2. to E-1
There is an electric field directed from E-2 to E-2.

However, at time 21, as is clear from FIG. 3, plasma due to silent discharge exists only on the surface of electrode E-2.
Due to the electric field directed to There will only be one unipolar ion extracted.

Then, at time 22, there is no silent discharge at the surface of electrode E-2, but instead there is a silent discharge only at the surface of electrode E-1, i.e. near its surface.
A plasma composed of positive and negative ions and electrons will exist.

However, at time 22, the relative potential is switched by the power source 8 so that electrode E-1 has a negative potential with respect to the ground point, and conversely, electrode E-2 has a positive potential with respect to the ground point. Therefore, at time 22, electrode E-1
− ions from the plasma that exist only on the surface of space 2
0 and reaches electrode E-2.

Therefore, at time 22, the only ions present in space 20 are those extracted from the plasma present on the surface of electrode E-1.

Similarly, in the space 20, the electrodes E-1, E-
Unipolar ions are alternately extracted toward the space 20 from both electrodes every 1/4 cycle of the fundamental frequency applied to the electrode.

Therefore, the power source 8 for generating a relative potential between the electrodes E-1 and E-2, the power source 6 for generating plasma on the surfaces of the electrodes E-1 and E-2, and the frequency of T. It is formed to have twice the frequency.

In this way, in the particle charging device according to the invention, only either positive or negative ions are present in the space 20 depending on the selection of the relative potentials existing between the electrodes E-1 and E-2. In addition, the direction of the electric field in the space 20 changes with a period of at least 20 cycles, so if there is a second
As shown in Figure 5, when particles are inserted, the power source 8
Particles are sufficiently charged by collision charge by electrons or ions selectively existing in space 20 due to the phase of The particles are not attracted by the particles and escape from this space as shown at 13 by a driving force such as gravity or wind power, thereby making it possible to reliably supply sufficiently charged particles to a predetermined work area.

However, in the space 20, there is usually gas in addition to the powder particles, so when particles flow through this space, some of the particles in the space 20 are bound to the electrode E- 1 or something approaching E-2 will appear.

However, on the surfaces of electrodes E-1 and E-2, electrode E-
As shown for 1, as shown by 1-1 and 2, since there is always an outwardly convex alternating electric field, the space 2
According to the present invention, the charged particles existing in the space 20 vibrate on the outwardly convex lines of electric force and therefore always receive a force repelled from the surface of the electrode. In the particle charging device, the opposing electrode E-1
゜Since particles do not adhere to the surface of electrode E-1 or E-2 due to the turbulence of airflow existing in space 20 on the surface of E-2 and change the supply capacity, the particle charging device can be used for a significantly long period of time. It becomes possible to operate continuously and stably.

In addition, in the particle charging device according to the present invention, the charged particles move in the space 20 while vibrating due to the relative potential existing between the electrodes E-1 and E-2, so there is usually no difference in mass or other differences between the particles. This causes a stirring effect between the particles and significantly improves charging efficiency.

In the particle charging device according to the present invention, the method of supplying alternating current voltages having a phase relationship as shown in FIG. It is possible.

The embodiment shown in FIG. 2 is one such method, in which a normal commercial frequency 50 Hz sine wave AC voltage is applied to the tap 12.

And electrode 2- buried near the surface of electrode E-2.
The AC voltage applied between 1 and 2-2 is directly stepped up by a transformer 7.

Next, a linear electrode 1-1 buried near the surface of electrode E-1
As a means for applying a voltage between
The phase is shifted by a period, and then the transformer 6 steps up and supplies the signal.

Next, as a method for generating a relative potential difference between the electrodes E-1 and E-2, the commercial frequency supplied to the tap 12 is converted to twice the frequency by the converter 10, and the phase is adjusted. Then, a relative potential difference is generated between the two electrodes by the transformer 8 through the position of the point 7-1 and the position of the point 6-1.

In this case, a neutral point 9 is installed on the secondary side of the transformer 8, and by charging the powder particles, excessive charges accumulated on the surface of each electrode can be discharged from there.

Generally, the insulator layer 1゜2 used for electrodes E-1 and E-2 does not pose much of an obstacle because the layer on the surface side of the electrode is extremely thin. This can be overcome without any problem by appropriately adjusting the resistance of the insulating layer on the electrode surface.

However, depending on the amount of powder passing through, the amount of charge carried away by the powder, and the accumulation of charges flying between the electrodes from other electrodes, the surface potential will shift slightly in both direct current and alternating current. Therefore, it may be convenient to make the phase relationship between the voltage applied to the electrodes and the voltage application device that generates the relative potential between the electrodes adjustable.

In an embodiment of the powder charging device according to the present invention, the voltage applied to each opposing planar silent discharge electrode may be of exactly the same frequency, and the voltage applied between the opposing electrodes may also be exactly twice this frequency. Since it has a fundamental frequency, it is easy to define the relative relationship between the frequency and phase of each power source very clearly, so there is no need to make delicate adjustments for the operation of the device. Its major feature is that it can easily construct a device that can guarantee extremely stable and reliable operation over a long period of time.

For the voltage applied to the planar silent discharge electrodes, it may be convenient to use a distorted alternating current waveform with an appropriate waveform in order to adjust the timing of discharge generation and the intensity of discharge in both silent discharge electrodes.

In addition, the alternating current voltage applied between each linear electrode is not only single-phase, but also multi-phase alternating current can be used. In this case, charged particles approaching both electrodes can be It can be quickly discharged from the device.

The waveform of the relative potential difference applied between the two electrodes is not only a simple rectangular wave as shown in Figure 3, but also an appropriate rectangular wave with a rest period in the middle depending on the timing of silent discharge generation, etc. Waveform alternating current can be used.

In addition to the planar silent discharge electrodes used in the particle charging device according to the present invention, in addition to those shown in FIGS. 1 and 2, as shown in FIG. A linear electrode 1-1 is buried shallowly, and a planar electrode 1-2' is buried at a depth approximately equal to the parallel linear electrode 1-2', and the linear electrode and the planar electrode are It is also possible to use a device in which a power source 6 is connected between the two as shown in the figure.

Further, as shown in FIG. 4, a linear electrode 1-1 covered with an insulator 1' is arranged parallel to the surface of the planar electrode 1-2', and the linear electrode 1-1 and the planar electrode 1 -2', and connect the AC power supply 6 between 1-7/ and 1.
A planar silent discharge electrode configured to generate a silent discharge between -2'' and 1-1 can also be used.

Furthermore, as shown in FIGS. 5 and 6, the linear electrodes 1-1 and 1-2 each covered with an insulating material are arranged in parallel so as to lie on a virtual surface without providing a specific surface. Then, connect the power supply 6 to this
It is also possible to apply an alternating voltage to the electrodes 1-2 in order to more reliably eliminate static electricity.
" is an example in which a bare electrode is used and only 1-1 is covered with an insulator 1'.

The ones shown in Figures 5 and 6 are convenient to use when it is necessary to supply ions to both sides of the electrode surface, but they can be placed inside another container. Of course, it can be used by preparing 1,000 rows and multiple columns.

As described in detail above, the structure of the planar silent discharge generating electrode used in the present invention can be modified in various ways.

In addition, the expression that opposing electrodes are parallel includes electrodes 1-1 and 1-2 arranged concentrically, etc., and the expression parallel Of course, this also includes parallel curved linear electrodes.

Moreover, the shape of the opposing planar silent discharge electrodes does not necessarily have to be flat; as shown in FIG. 8, one electrode is a cylindrical electrode E-1' and the other electrode E-2'. is composed of electrodes formed on concentric cylinders facing it, and particles are supplied in a donut shape between these opposing cylindrical electrodes by a rotating disk device 3' or the like. Of course, this is possible.

In this case, it is of course possible to use various electric field devices, as shown at 30 in FIG. 8, to supply sufficiently charged charged particles to the target location.

Next, embodiments of the present invention will be described in detail.

For the electrode E-1, linear electrodes 1-Ll-2 with a diameter of 0.2 mrn were buried at a pitch of 3 mm at a depth of 0.5 mm from the surface of a glass plate of about 10"Qcm, and these electrodes were Every other wire is connected in the same phase, and the voltage applied between these linear electrodes is 3500V, and the frequency is 50V.
It is Hz.

In this case, the total thickness of the glass layer 1 is 3 mm.

Electrode E-2 with exactly the same structure as this is electrode E-1 and 501
They are arranged facing each other with an interval of trIL, and the voltage applied by the power source 7 is exactly the same as the voltage applied by the power source 6.

The voltage applied to the power sources 6 and 7 is 1 in phase only.
Shift by /4 cycles.

Next, a thyristor-based cutting tube device is used between electrode E-1 and electrode E-2 to apply a rectangular wave as shown in R in Figure 3 for 100 cycles to set a relative potential of 5000V to electrode E. -1 and electrode E-2.

In this way, when 200 g of powder is distributed and supplied to the space 20 per minute, and the passing distance of the powder is set to 30 crIL, the powder is charged unipolarly, and the average charge is the theoretical saturated charge. It is possible to obtain an average charge amount of 0.98 xio14 coulombs for particles with an average particle diameter of 26 microns, and it is possible to perform fully continuous automatic operation for more than 500 hours.

As explained above, the present invention uses a pair of electrodes separated by a solid insulator to form a planar ion generating electrode, so that silent discharge can be performed with effective power consumption by applying an alternating current voltage between the electrodes. Moreover, by forming at least one of the electrodes into a linear electrode group, silent discharge can be caused in the ion generating electrode in a planar manner.

In addition, by shifting the effective application time of the AC voltage applied to the opposing ion-generating electrodes, it is possible to alternately generate silent discharges at the opposing ion-generating electrodes.
Moreover, a silent discharge is generated by applying a voltage between the planar ion generating electrodes so that the planar ion generating electrode that is generating the silent discharge always has the same polarity potential difference with respect to the other planar ion generating electrode. It is possible to always extract only one of the positive and negative ions generated on the charged side into the charged space, and since ions are generated in a planar shape on the planar ion generation electrode, particles passing through the charged space However, it becomes possible to charge the battery evenly and with high efficiency.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of essential parts of an embodiment of the present invention, FIG. 2 is a schematic circuit diagram, FIG. 3 is a waveform diagram of each set point, and FIGS.
FIG. 8 is a schematic explanatory diagram of each embodiment. E-1, E-2... Planar ion generating electrode, 1゜2... Insulator, 1-1, 2-1... Parallel linear electrode, 1 -2, 2-2...Parallel linear electrode, 1-3...Surface layer of insulator, 1-4...
...Surface layer of insulator, 12', 1-2"...
Planar electrode, 10... converter, 11... phase shifter, 20... charging space.

Claims (1)

[Claims] A planar ion generating electrode 7C is provided with a pair of electrodes separated by a solid insulator, and at least one of the electrodes is arranged in parallel in large numbers as a group of linear electrodes, and the planar ion generating electrode is opposed. An alternating current voltage is applied between each of the pair of electrodes so as to cause a silent discharge in the charged space formed by the electrode and the planar ion generating electrode, and the effective application time of one alternating voltage is the effective application time of the other alternating voltage. and means for shifting the voltage between the planar ion generating electrodes such that the planar ion generating electrode generating silent discharge always has the same polar potential difference with respect to the other planar ion generating electrode. A charged particle generator comprising: means for applying voltage;