JP4027410B1 - Inspection method and inspection apparatus for corona discharge ionizer - Google Patents

Abstract

[Object] To detect only a true current due to ions generated from an emitter of a corona discharge ionizer, and further to detect a neutralization current that actually contributes to neutralization of an object to be neutralized. It is possible to check the degree of deterioration, static elimination performance, etc.
In a corona discharge ionizer in which a ground electrode is disposed in the vicinity of an emitter to which a high voltage is applied, a total current flowing through the ground electrode and a first induced current due to the high voltage applied to the emitter are simultaneously applied. Measure and estimate a second induced current flowing through the ground electrode by the electric field formed by the emitter, which is a component of the total current, from the first induced current, and from the difference between the total current and the second induced current The true current generated by the ions generated by the emitter is measured.
[Selection] Figure 1

Description

  The present invention relates to an inspection method and an inspection apparatus for a corona discharge ionizer capable of detecting the degree of contamination and deterioration of an emitter of a corona discharge ionizer and further capable of detecting a discharge current that actually contributes to discharge of an object to be discharged. Is.

As is well known, a corona discharge ionizer ionizes ambient air by applying a high voltage to an emitter to generate positive or negative ions (charged particles). The electricity is removed by supplying the product.
For example, in an AC ionizer, by applying an AC high voltage to one emitter, positive and negative ions are alternately generated and supplied to the object to be discharged.

However, some of the ions generated from the emitter are absorbed by the ground electrode disposed in the vicinity of the emitter and flow as a current, and the remaining ions are supplied to the object to be neutralized and contribute to static elimination.
At this time, if fine particles are attached to the tip of the emitter, or if the radius of curvature of the tip is increased due to deterioration of the emitter, the amount of ions generated by the emitter decreases. The amount will also decrease.

  Conventionally, even in such a state, if the ionizer power switch is turned on, it is often assumed that ions are naturally generated. Even if the amount of ion generation was completely zero, this could not be noticed.

  As a solution to such a problem, it is conceivable to measure and display the current flowing by the ions generated by the emitter. Specifically, as described in Patent Document 1, a method is known in which a current measurement resistor or ammeter is connected to a ground electrode in the vicinity of the emitter, and a current corresponding to the amount of ions generated by the emitter is measured. ing.

JP 2004-127858 A (paragraph [0017], FIG. 3 etc.)

  However, since the current measured by the method described in Patent Document 1 is dominated by the induced current (displacement current) that flows through the ground electrode due to the electric field formed by the emitter to which a high voltage is applied, it depends on the ions generated from the emitter. There was a problem that current (hereinafter also referred to as true current) was almost impossible to measure.

  Therefore, the problem to be solved by the present invention is to detect only the true current by removing the induced current from the total current flowing through the ground electrode, and from this true current, the degree of contamination and deterioration of the emitter, and the actual charge removal. An object of the present invention is to provide a corona discharge ionizer inspection method and inspection apparatus capable of detecting a static elimination current that contributes to static elimination of an object.

In order to solve the above problem, a corona discharge ionizer inspection method according to claim 1 is a corona discharge ionizer in which a ground electrode is disposed in the vicinity of an emitter to which a high voltage is applied.
Simultaneously measuring the total current flowing through the ground electrode and the first induced current due to the high voltage applied to the emitter;
From the first induced current, a second induced current flowing through the ground electrode by an electric field formed by the emitter, which is a component of the total current, is estimated,
The true current generated by the ions generated by the emitter is measured from the difference between the total current and the second induced current.

According to a second aspect of the present invention, there is provided an inspection method according to the first aspect, wherein the contamination and deterioration degree of the emitter are detected from the true current.
According to a third aspect of the present invention, there is provided an inspection method according to the first aspect, wherein, from the true current, a static elimination current that flows due to ions that reach the static elimination object is measured.

The corona discharge ionizer inspection apparatus according to claim 4 is a corona discharge ionizer in which a ground electrode is disposed in the vicinity of an emitter to which a high voltage is applied.
Means for measuring the total current flowing through the ground electrode;
Means for measuring a first induced current due to the high voltage applied to an emitter simultaneously with the total current;
Means for estimating, from a first induced current, a second induced current flowing in the ground electrode by an electric field formed by an emitter, which is a component of the total current;
And an arithmetic means for measuring a true current generated by ions generated by the emitter from a difference between the total current and the second induced current.

According to a fifth aspect of the present invention, there is provided the inspection apparatus according to the fourth aspect, wherein the contamination or deterioration degree of the emitter is detected from the true current.
According to a sixth aspect of the present invention, in the inspection apparatus according to the fourth aspect of the present invention, the static elimination current that flows due to the ions that reach the static elimination object is measured from the true current.

The inspection apparatus according to claim 7 is any one of claims 4 to 6,
The means for measuring the first induced current includes a high voltage generating means for applying a high voltage to the emitter and an auxiliary electrode for detecting the first induced current disposed in the vicinity of the cable connecting the emitter. It is.
Moreover, the inspection apparatus which concerns on Claim 8 in any one of Claims 4-6,
The means for measuring the first induced current includes an auxiliary electrode that is disposed in the vicinity of the emitter and detects the first induced current.

The inspection device according to claim 9 is the method according to claim 7 or 8,
A first resistor connected to the auxiliary electrode;
A second resistor connected to the ground electrode;
A differential amplification circuit for amplifying a difference between a voltage drop generated in the first resistor by the first induced current and a voltage drop generated in the second resistor by the total current as the arithmetic means;
By making at least one of the first resistor and the second resistor variable, a voltage drop generated in the first resistor by the first induced current is equal to a voltage drop generated in the second resistor by the second induced current. To do.

  According to the corona discharge ionizer inspection method and inspection apparatus of the present invention, it is possible to remove only the induced current flowing through the ground electrode by the electric field formed by the emitter, and to reliably measure only the true current due to the ions generated by the emitter. . For this reason, based on the measured true current, it is possible to detect the degree of contamination and deterioration of the emitter, the static elimination current that contributes to the static elimination of the object to be neutralized, etc. it can.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, FIG. 1 is a block diagram showing a first embodiment of the present invention. In FIG. 1, reference numeral 10 denotes a high voltage generation circuit that generates an alternating high voltage, and a needle-like emitter 20 is connected to the output side of the circuit via a cable 21. A ring-shaped ground electrode 30 is concentrically disposed in the vicinity of the emitter 20, and the ground electrode 30 has a connection point A and a resistance R _G (corresponding to a second resistance in the claims). Is grounded.

On the other hand, a cylindrical auxiliary electrode 40 is provided so as to surround the cable 21 between the high voltage generation circuit 10 and the emitter 20, and the auxiliary electrode 40 includes a connection point B and a variable resistor R _C (claims). Corresponding to the first resistor in FIG.
The connection points A and B are connected to the non-inverting input terminal and the inverting input terminal of the operational amplifier 50 via resistors R ₂ and R ₁ , respectively, and the non-inverting input terminal is grounded via a resistor R _4. Yes. R ₃ is a feedback resistor.
Here, the operational amplifier 50 and the resistors R _{1 to} R ₄ constitute a known differential amplifier circuit, and the resistance values are set to R ₁ = R ₂ and R ₃ = R ₄ for simplification. Yes.

Next, the operation principle of this embodiment will be described.
First, when a high voltage is applied to the emitter 20 by the high voltage generation circuit 10, the air around the emitter 20 is ionized. In this case, the total current I _G flowing to the ground electrode 30, the induced current (displacement current) by Shin current I _R and the electric field emitter 20 is formed by generating ions from the sum of the I _I, formula respect true current I _R 1 is led. The induced current I _I corresponds to the second induced current in the claims.
[Formula 1]
I _R = I _G -I _I

On the other hand, the current I _C to be taken out through the auxiliary electrode 40 is only induced current caused by the true current I is not affected by _R, a high voltage applied from a high voltage generating circuit 10 to the emitter 20. However, because the shape of the ground electrode 30 and the auxiliary electrode 40 differs, the different sizes of the induced current I _C flowing through the auxiliary electrode 40 and the induction current I _I flowing through the ground electrode 30. The induced current I _C corresponds to the first induced current in the claims.
The coefficient α indicating the relationship between the induced current I _I and the induced current I _C is
α = I _I / I _C
Then, Formula 1 becomes Formula 2.
[Formula 2]
_{I R = I G -I I =} I G -αI C

Here, the induced current flows to the ground electrode 30 on the basis of the induced current I _{C (first} induced current) is measured at the same time, the induced current I _C flowing through the auxiliary electrode 40 and the total current I _G flowing through the ground electrode 30 I _If the difference (I _G −I _I ) between the total current I _G and the induced current I _I is obtained by estimating _I (second induced current), the true current I _R can be measured by the equation 1.
Since the true current I _R proportional to the concentration of product ions by the emitter 20, if measure the true current I _R, it is possible to estimate the contamination and deterioration degree of the emitter 20, without the neutralization product (shown at the bottom of the emitter 20 ), The magnitude of the static elimination current that contributes to static elimination can be estimated.

In this embodiment, the difference calculation according to Formula 2 is equivalently performed by a differential amplifier circuit including the operational amplifier 50.
That is, in the circuit of FIG. 1, a voltage drop (= I _I × R _G ) in the resistor R _G due to the induced current I _I and a voltage drop (= I _C × R _C ) in the variable resistor R _C due to the induced current I _C are equal, the output voltage _{V OUT} of the operational amplifier 50, since become magnitude proportional to the voltage drop (= _{I R} × _{R G)} at the resistor _{R G} according to the true current _{I R,} by detecting the output voltage _{V OUT} it is possible to measure the true current I _R.

Further, in order to equalize the voltage drop across the resistor _{R G} described above (= _{I I} × _{R G)} and the voltage drop across the variable resistor _{R C (= I C × R} C) is the connection point A by an oscilloscope or the like, B And the variable resistor _RC may be adjusted so that these voltages are equal. By the adjustment operation of the variable resistor _RC, the induced current I _I can be estimated from the induced current I _C equivalently.

In this case, although the current flowing to the connection point A is the total current _{I G (= I R + I} I), the induced current _I I whereas the induced current _{I I} and the true current _{I R} are out of phase, Since I _C has the same phase, the voltage drop at the resistor R _G (= I _I × R _G ) and the voltage drop at the variable resistor R _C (= I _C × R _C ) are observed with an oscilloscope or the like. It is possible to adjust the variable resistor _RC so that
The fixed resistance resistor R _G in this embodiment, the resistor R _C is a variable resistor, a variable resistor the resistance R _G, the resistance R _C may be adjusted a resistor R _G as a fixed resistor.

As described above, according to this embodiment, it is possible to measure the true current I _R with a simple circuit configuration as shown in FIG. 1, contamination of the emitter 20 Ya by using the output voltage V _OUT of the operational amplifier 50 It is possible to display or output the deterioration state, the magnitude of the static elimination current, and the like.
2 is an enlarged view of the specific configuration of the ground electrode 30 in FIG. 1, wherein 31 is a ground electrode body, 32 is an insulator, and 33 is a lead wire connected to a resistor _RG . In FIG. 2, illustration of the differential amplifier in FIG. 1 is omitted for convenience.

Figure 3 is a waveform diagram for explaining the effects of the first embodiment described above, the output voltage V _OUT of the operational amplifier 50 when the new emitter (tip radius of curvature 10 [mu] m) a high voltage is applied to, the voltage drop across the resistor _{R G} according to the total current _{I G} (referred to as _{V G),} shows a voltage drop (referred to as _{V C)} of the variable resistor _{R C} by the induction current _{I C.}
On the other hand, FIG. 4 shows waveforms when V _OUT , V _G , and V _C are measured in the same manner as in FIG. 3, using an emitter having a radius of curvature of 500 μm in order to simulate a state in which the emitter has deteriorated. FIG.

3, as it is apparent from a comparison of FIG. 4, when the emitter is new can be obtained an output voltage V _OUT having a significant value, clear the magnitude of the true current I _R from the output voltage V _OUT is a detectable, the emitter deteriorates, the output voltage V _OUT that is true current I _R will not be confirmed most.
From this, it can be seen that according to the first embodiment, the contamination and deterioration state of the emitter, the true current, and the static elimination current that actually contributes to static elimination can be easily grasped.

Next, FIG. 5 is a block diagram showing a second embodiment of the present invention.
In the first embodiment described above, in order to detect the induced current I _C, but using a cylindrical auxiliary electrode 40 surrounding the cable 21, as shown in the second embodiment of FIG. 5, the cable 21 A plate-like auxiliary electrode 41 may be disposed in proximity.
FIG. 6 is a block diagram showing a third embodiment of the present invention. In place of the auxiliary electrodes 40 and 41, an auxiliary electrode 42 formed in a coil shape as shown in FIG. You may do it.

Furthermore, FIG. 7 is a block diagram showing a fourth embodiment of the present invention.
This embodiment is an example in which the auxiliary electrode 43 is constituted by a covered electric wire, and the tip portion of the auxiliary electrode 43 is arranged in the vicinity of the emitter 20. Even if the auxiliary electrode 43 having such a configuration is used, the induced current I _C can be detected.

In the enlarged view of the distal end portion of the auxiliary electrode 43 in FIG. 7, reference numeral 44 denotes a lead wire connected to the variable resistor _RC , and 45 denotes an insulator coated so as to cover the distal end portion of the lead wire 44. In this way, by completely covering the tip of the lead wire 44 adjacent to the emitter 20 with the insulator 45, it is possible to prevent the auxiliary electrode 43 from detecting even the true current due to the ions generated from the emitter 20. can do.

  In each of the above embodiments, the AC corona discharge ionizer has been described. However, the measurement principle according to the present invention can be applied to a DC corona discharge ionizer.

It is a block diagram which shows 1st Embodiment of this invention. It is explanatory drawing of the principal part of FIG. It is a wave form diagram for demonstrating the effect of 1st Embodiment. It is a wave form diagram for demonstrating the effect of 1st Embodiment. It is a block diagram which shows 2nd Embodiment of this invention. It is a block diagram which shows 3rd Embodiment of this invention. It is a block diagram which shows 4th Embodiment of this invention.

Explanation of symbols

10: High voltage generation circuit 20: Emitter 21: Cable 30: Ground electrode 31: Ground electrode body 32: Insulator 33: Lead wire 40-43: Auxiliary electrode 44: Lead wire 45: Insulator 50: Operational amplifier _RC : Variable Resistance (first resistance)
R _G : Resistance (second resistance)
R _{1 to} R ₄ : Resistance

Claims (9)

In a corona discharge ionizer in which a ground electrode is arranged in the vicinity of an emitter to which a high voltage is applied,
Simultaneously measuring the total current flowing through the ground electrode and the first induced current due to the high voltage applied to the emitter;
From the first induced current, a second induced current flowing through the ground electrode by an electric field formed by the emitter, which is a component of the total current, is estimated,
A corona discharge ionizer inspection method, comprising: measuring a true current generated by ions generated by an emitter from a difference between the total current and a second induced current. In the corona discharge ionizer inspection method according to claim 1,
A method for inspecting a corona discharge ionizer, characterized by detecting contamination or deterioration of an emitter from the true current. In the corona discharge ionizer inspection method according to claim 1,
An inspection method for a corona discharge ionizer, characterized in that, from the true current, a static elimination current that flows due to ions that reach the static elimination object is measured. In a corona discharge ionizer in which a ground electrode is arranged in the vicinity of an emitter to which a high voltage is applied,
Means for measuring the total current flowing through the ground electrode;
Means for measuring a first induced current due to the high voltage applied to an emitter simultaneously with the total current;
Means for estimating, from a first induced current, a second induced current flowing in the ground electrode by an electric field formed by an emitter, which is a component of the total current;
An arithmetic means for measuring a true current generated by ions generated by the emitter from a difference between the total current and the second induced current;
A corona discharge ionizer inspection apparatus characterized by comprising: In the corona discharge ionizer inspection device according to claim 4,
An inspection apparatus for a corona discharge ionizer, wherein the contamination of the emitter and the degree of deterioration are detected from the output of the arithmetic means. In the corona discharge ionizer inspection device according to claim 4,
An inspection apparatus for a corona discharge ionizer, wherein a discharge current that flows due to ions that reach a charge removal object is measured from an output of the calculation means. In the inspection apparatus for a corona discharge ionizer according to any one of claims 4 to 6,
The means for measuring the first induced current is:
A corona discharge ionizer inspection apparatus comprising a high voltage generating means for applying a high voltage to an emitter and an auxiliary electrode disposed in the vicinity of a cable connecting the emitter and detecting a first induced current . In the inspection apparatus for a corona discharge ionizer according to any one of claims 4 to 6,
The means for measuring the first induced current is:
A corona discharge ionizer inspection apparatus comprising an auxiliary electrode disposed in the vicinity of an emitter and detecting a first induced current. In the inspection apparatus for a corona discharge ionizer according to claim 7 or 8,
A first resistor connected to the auxiliary electrode;
A second resistor connected to the ground electrode;
A differential amplifying circuit for amplifying a difference between a voltage drop generated in a first resistor by a first induced current and a voltage drop generated in a second resistor by the total current;
With
By making at least one of the first resistor and the second resistor variable, a voltage drop generated in the first resistor by the first induced current is equal to a voltage drop generated in the second resistor by the second induced current. A corona discharge ionizer inspection apparatus characterized by:

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