JPH05330805A - Counter electrode type ozone generator - Google Patents

Abstract

PURPOSE:To provide the ozone generator which is stable usable over a long period of time without executing adjustment and maintenance and is suitable for home and business uses. CONSTITUTION:A switching means 5 is interposed in a feedback line 4 of an oscillation circuit constituted of a high-voltage control circuit 1 and a high- voltage transformer 2. This switching means 5 is controlled by the intermittent operation signals and stop signals to be outputted from an intermittent control means 6. As a result, a corona discharge is intermittently generated at the voltage sufficiently higher than the discharge initiation voltage. As a result, the discharge does not stop even if electrodes and dielectric are stained by long-term use even if the use environment changes. Further, the discharge voltage is high and, therefore, dust, etc., are burned down and hardly accumulate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ozone generator for generating ozone by causing corona discharge between discharge electrodes facing each other in a casing having an intake port and an exhaust port. More specifically, it relates to a technology for controlling the amount of ozone generated in such an ozone generator.

[0002]

2. Description of the Related Art A conventional counter electrode type ozone generator has a circuit shown in FIG. This is generally RCC (Ring
ing Choke Converter) type voltage generator circuit 101 is also used. The circuit is a high voltage control circuit 102 including a power transistor (switching element), and the high voltage control circuit 102.
It also has a high-voltage transformer 103 that constitutes an oscillation circuit. Note that, unlike a normal switching regulator,
The high frequency waves output from the high voltage transformer 103 are not rectified but output to the discharge electrode 104 as AC. Discharge electrode 104
Is composed of electrodes 105 and 107 and a dielectric 106.

As shown by W ₁ in FIG. 3, the output voltage V _pp (peak-to-peak value) from the high-voltage transformer 103 is adjusted by the high-voltage control circuit 102 to adjust the ozone generation amount. There is. For example, in order to generate ozone 5 mg / H, the applied voltage is set to 9 kV _PP and 100 mg / H
When it is H, it is set to 11 kV _pp . In particular, in the case of 5 mg / H, in order to suppress the ozone generation amount, the operation is performed at a voltage slightly higher than the minimum voltage (corona discharge starting voltage) V ₁ required to generate corona discharge.

[0004]

Recently, focusing on the deodorizing action (and the sterilizing action) based on the oxidizing action of ozone, the deodorizing effect in the domestic business, such as the deodorization in a closed space such as a refrigerator, an automobile, a trash can, etc. Attempting to utilize. However, since ozone is generated in the environment where the user is present, the ozone concentration must be as low as possible, and at least lower than the allowable concentration (for example, 8 hours or less per day in an environment of 0.1 ppm).

If the conventional method of controlling the applied voltage V _pp is used to suppress the ozone generation amount as much as possible, a voltage slightly higher than the corona discharge starting voltage is applied between the electrodes. However, in such a method, the following (1) to (3)
Due to such changes in the operating condition, it becomes difficult to maintain the corona discharge, and ozone generation may stop. For example, in the generator of FIG. 3, when the ozone is adjusted to 20 mg / H or less, the ozone generation amount becomes unstable and sometimes stops.

(1) After being used for a long time, the electrode 105 and the dielectric 1
When the surface of 06 becomes dirty, the discharge space (gap) 10
8 increases, and the voltage applied as a divided voltage between the discharge gaps 108 falls below the discharge start voltage V ₁ .

(2) When the ambient temperature decreases, the base-emitter voltage rises due to the temperature dependence of the parameters of the power transistor used in the high voltage control circuit 102,
The voltage generated by the voltage generation circuit 101 decreases. Therefore, the voltage applied between the discharge electrodes is lower than the corona discharge starting voltage V ₁ .

(3) When the humidity in the container is high, the corona discharge starting voltage V ₁ of the ozone generating gas rises. At the same time, the dirt on the surface of the electrode 105 and the dielectric (insulator) 106 absorbs moisture, so that the voltage applied with a partial voltage between the discharge gaps is further improved as compared with the case where the surfaces of the electrode 105 and the dielectric 106 are simply dirty. descend.

When the operating state changes and ozone generation stops as described above, it is possible to restart corona discharge by gradually increasing the voltage applied across the discharge gap. is there. However, it is quite difficult for general users to adjust the applied voltage so that it slightly exceeds the corona discharge starting voltage each time the operating state changes, and to continue the operation while suppressing the ozone generation amount.

On the other hand, a high voltage can be applied between the discharge gaps from the initial stage of operation so that the corona discharge does not stop even when the operation state changes. However, in that case, at the beginning of operation, especially when the electrodes are not dirty,
This will exceed the target amount of ozone generated.

It is a technical object of the present invention to solve the problems of the conventional ozone generator and to provide an ozone generator which can be stably operated while maintaining a low ozone generation amount. Further, it is a technical object of the present invention to provide an ozone generator suitable for home use and for business use, which can be stably operated for a long time without being bothered by adjustment and maintenance.

Further, in the case of the above (2), even if the voltage applied between the discharge electrodes does not go below the corona discharge starting voltage V ₁ , the ozone generation amount decreases from the predetermined value.
Further, on the contrary, when the temperature around the power transistor rises, the ozone generation amount exceeds a predetermined value, and the ozone generation amount always fluctuates depending on the ambient temperature.
A second object of the present invention is to provide an ozone generator capable of automatically compensating for such variation in ozone generation amount due to temperature.

[0013]

An ozone generator according to claim 1 is a casing having an intake port and an exhaust port, discharge electrodes opposed to each other in the casing, and a voltage for applying a high-frequency voltage between the discharge electrodes. A counter electrode type ozone generator having a supply circuit, wherein the voltage supply circuit generates a high frequency voltage sufficiently higher than a corona discharge starting voltage, and a high frequency voltage generation circuit receiving an operation signal. Is applied to the discharge electrode and also stops the application of the high frequency voltage to the discharge electrode in response to the stop signal and the operation signal and the stop signal are intermittently applied to the switching means. In addition, an intermittent control means for adjusting the time ratio of the operation signal and the stop signal according to the desired ozone generation amount is provided.

An ozone generator according to a second aspect of the present invention is based on the high frequency voltage generating circuit having an active element having a temperature coefficient, a temperature detecting means for detecting a temperature in the vicinity of the active element, and an output of the temperature detecting means. Then, the temperature compensation means for correcting the time ratio of the operation signal output by the intermittent control means and the stop signal is provided.

[0015]

In the ozone generator of the first aspect, the high frequency voltage generating circuit generates a high frequency voltage having a voltage sufficiently higher than the discharge starting voltage. Therefore, even if the operating condition changes due to long-term use, stable discharge can be continued. However, since the amount of ozone generated exceeds the allowable value as it is, the switching means and the intermittent control means intermittently apply the high frequency voltage to the discharge electrode. Therefore, while maintaining the discharge voltage at a value where the discharge continues stably,
The time-averaged ozone generation amount can be suppressed below the allowable value. Further, the intermittent control means can adjust the time ratio of the operation signal and the stop signal given to the switching means, so that the ozone generation amount can be set low without paying attention to the discharge voltage.

In the ozone generator of claim 2, the temperature detecting means detects the temperature in the vicinity of the active element having a temperature coefficient, and the high frequency voltage generated by the high frequency voltage generating circuit fluctuates due to the temperature fluctuation of the active element. However, the time ratio between the operation signal and the stop signal is automatically adjusted. Therefore, even if the voltage between the discharge electrodes changes due to temperature change, the total ozone generation amount does not change.

[0017]

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

FIG. 1 is a block diagram showing an embodiment of the ozone generator of the present invention, and FIG. 2 is a concrete circuit diagram thereof.

The ozone generator of FIG. 1 comprises a high voltage control circuit 1 having the same power transistor (Q _{1 in} FIG. 2) as in the conventional one, and a high voltage transformer 2. The high voltage control circuit 1 and the high voltage transformer 2 form a high frequency voltage generating circuit according to claim 1. A discharge electrode 3 is connected to the secondary side of the high voltage transformer 2. Further, the line 4 for feeding back the oscillation timing signal from the high voltage transformer 2 to the power transistor is provided with a switching means 5 for switching the feedback signal ON-OFF. This switching means 5
Upon receiving an operation signal from the intermittent control means 6, a high frequency voltage is applied to the discharge electrode 3 and a stop signal is received to stop the application. Then, the intermittent control means 6 intermittently sends the operation signal and the stop signal to the switching means 5 alternately at a predetermined time ratio. Further, the intermittent control means 6 can adjust the time ratio of the operation signal and the stop signal.

Further, in this embodiment, there are provided temperature detecting means for detecting the temperature in the vicinity of the power transistor and temperature compensating means 7 for changing the time ratio of the operation signal and the stop signal according to the output. That is, the power transistor is an active element having the temperature coefficient of claim 2.

This device constitutes an oscillating circuit with a high voltage control circuit 1 and a high voltage transformer 2. For example, the voltage V _pp (peak-to-peak value) is 13 kV _pp and the cycle h ₁ is 40-5.
Create a high frequency W ₁ of 0 μSec. And intermittent control means 6
Has a period h ₂ of 200 to 10 mSec and a pulse width w of 5 mSec
A rectangular pulse wave P (at 25 ° C.) is created. By this pulse wave P, the operation signal and the stop signal are given to the switching means 5 at a predetermined time ratio. Upon receipt of this, the switching means 5 turns on and off the feedback signal.
By switching the FFs, the waveform of the high frequency voltage applied to the discharge electrode 3 is changed to the shape of W ₂ in FIG. The period h ₂ of the pulse wave P is adjusted within the range of 200 to 10 mmSec according to the target ozone generation amount (5 to 100 mg / H).

Therefore, the voltage V applied to the discharge electrode 3
_{Since pp} is sufficiently higher than the firing voltage of 8-9 kV _pp ,
Even if the surface of the electrode or the dielectric is slightly soiled or the humidity rises or the temperature in the vicinity of the power transistor drops due to long-term use, stable discharge can be continued. The ozone generation amount is the time ratio of the operation signal and the stop signal of the intermittent control means 6 (on-duty ratio:
By reducing w / h ₂ ) it is possible to reduce to a desired concentration. That is, if the on-duty ratio is made sufficiently small, stable operation can be achieved even with a much smaller ozone generation amount, for example, 5 mg / H, than in the case where a voltage slightly higher than the discharge start voltage is continuously applied.

In this ozone generator, a higher voltage is applied for a short time as compared with the method of continuously applying a voltage, so dust and dirt are burnt and scattered by the discharge. Therefore, there is also an advantage that dust and dirt are less likely to accumulate on the electrodes and the dielectric.

Even if the ambient temperature further lowers and the base-emitter voltage of the power transistor rises, which causes the applied voltage to drop, the temperature compensating means 7 automatically adjusts the high-frequency voltage application time (pulse width w). The actual amount of ozone generated does not decrease. The temperature compensation of the power transistor is preferably about 2% / ° C. For example, when the reference temperature rises 10 ° C from 25 ° C to 35 ° C, the voltage application time is reduced by 20% (1 mSec) to 4 mSec.

FIG. 2 specifically shows an electric circuit of the ozone generator of FIG. In FIG. 2, Q ₁ is a power transistor and forms an oscillation circuit (high frequency voltage generation circuit) together with the high voltage transformer 2. And Q ₂ is a high-voltage transformer 2 to be passed through the base of the power transistor Q ₁ when the ON
It is an ON-OFF transistor that feeds the feedback current from the line 8 to the line 8. That is, the ON-OFF transistor Q ₂ is the switching means according to claim 1, which functions as an ON-OFF switch of the power transistor Q ₁ . And ON
-OFF transistor Q ₂ is intermittent rectangular pulse P integrated circuit IC ₄ that (for example, monostable multivibrator 74HC123) generates a clock signal generator is turned ON when a high of (H). Then, a feedback current to be supplied to the base of the power transistor Q ₁ is supplied to the line 8 to stop the oscillation of the oscillator circuit. When the pulse P is low (L), the ON-OFF transistor Q ₂ is turned off,
A feedback current is caused to flow through the base of the power transistor Q ₁ to continue oscillation. The operation signal of the switching means (ON-OFF transistor Q ₂ ) in claim 1 corresponds to low of the intermittent rectangular pulse P, and the stop signal corresponds to high. That is, it is controlled by low active.

The period h ₂ of the intermittent rectangular pulse P is adjusted by changing the time constant defined by the capacitor C ₁ and the series of resistors R _1, R ₂ , R ₃ and R ₄ . In addition, the overall resistance value can be set to L mode, M mode,
It can be changed by selecting one of the H modes.
Therefore, the integrated circuit IC ₄ for generating the clock signal,
The capacitor C ₁ and the series of resistors R _1, R ₂ , R ₃ , R ₄ and the selection switch 9 are the intermittent control means according to claim 1.

The pulse width w is the thermistor TH and the resistance R.
It is automatically adjusted by the time constant determined by the combined resistance value of ₅ and the capacitor C ₂ . That is, the thermistor TH is a temperature detecting means that outputs a change in the resistance value according to the rise and fall of the temperature in the vicinity of the power transistor Q ₁ . The resistor R ₅ and the capacitor C ₂ are temperature compensating means for automatically adjusting the pulse width w to be narrow or wide based on the output (resistance value) of the temperature detecting means.

Two coils T on the primary side of the high voltage transformer 2
_1, T ₂ and the coil T ₃ on the secondary side are in reverse contact with each other, and a DC voltage E ₁ is applied to the _two coils T _1, T ₂ through the power supply stabilizing circuit 10. In addition, the two coils T _{1 and} T on the primary side
The coils ₂ and T ₃ on the secondary side may be connected in sequence.

In the above embodiment, the integrated circuit IC ₄ is used as a circuit for turning on / off the power transistor, but it is also possible to generate the rectangular wave P by another analog oscillation circuit or the like.

[0030]

In the ozone generator according to the first aspect of the present invention, the discharge voltage is maintained higher than the discharge start voltage, and the ozone generation amount is adjusted by adjusting the application time. Therefore, the discharge does not stop due to contamination of the electrodes, increase in humidity, or decrease in temperature, and ozone generation can be stably maintained. Moreover, since the application time can be freely adjusted, the ozone generation amount can be stably reduced as compared with the conventional one. Further, since the discharge is performed at a higher voltage, dust and dirt on the electrodes and the dielectric are burned, and the deterioration of the discharge condition does not proceed. Therefore, it is possible to further extend the period during which the device can be continuously used without adjusting maintenance.

In the ozone generator of the second aspect, the application time to the discharge electrode is automatically adjusted even if the temperature of the active element fluctuates and the height of the high frequency voltage fluctuates. Therefore, the actual amount of ozone generated does not change significantly.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an ozone generator of the present invention.

FIG. 2 is an electric circuit diagram showing a specific control circuit of the ozone generator of FIG.

FIG. 3 is a block diagram showing an example of a conventional ozone generator.

[Explanation of symbols]

 1 High Voltage Control Circuit 2 High Voltage Transformer 3 Discharge Electrode 5 Switching Means 6 Intermittent Control Means 7 Temperature Compensation Means

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[Procedure amendment]

[Submission date] June 2, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

Claims (2)

[Claims] 1. A counter electrode type ozone generator comprising: a casing having an intake port and an exhaust port; a discharge electrode arranged in the casing so as to face each other; and a voltage supply circuit for applying a high frequency voltage between the discharge electrodes. A high-frequency voltage generation circuit that generates a high-frequency voltage that is sufficiently higher than the corona discharge start voltage, and receives the operation signal to apply the high-frequency voltage from the high-frequency voltage generation circuit to the discharge electrode and to receive a stop signal. A switching means for stopping the application of the high frequency voltage to the discharge electrode and an operation signal and a stop signal are intermittently applied to the switching means, and the time ratio of the operation signal and the stop signal is set to a desired ozone generation amount. A counter electrode type ozone generator, comprising: an intermittent control unit that adjusts accordingly. 2. The ozone generator according to claim 1, wherein the high frequency voltage generating circuit having an active element having a temperature coefficient, temperature detecting means for detecting the temperature in the vicinity of the active element, and the temperature detecting means An ozone generator comprising: a temperature compensating unit that corrects a time ratio of the operation signal and the stop signal output from the intermittent control unit based on the output.