JPH0878136A - Ultrasonic static eliminator and static eliminating method - Google Patents

Abstract

PURPOSE: To prevent the leak of a high voltage directly applied to a storing water by emitting an ultrasonic wave of 1.5MHz or more by a piezoelectric magnetic oscillator present in a storing water vessel by use of a direct current converted by a bridge diode. CONSTITUTION: The alternate current generated on a secondary side by the step down of an AC/AC transformer is used as a driving power source for ultrasonic generation, guided to a bridge diode D1 through a low voltage serge absorber ZI, and shaped to a direct current. A ceramic oscillator UR constitutes an oscillating circuit by the switching operation of a power transistor Q, a diode D2, capacitors C5, C6, C8, resistors R3, R4 to emit an ultrasonic wave of 1.5MHz or more. Since a piezoelectric magnetic oscillator present in storing water has insulating property itself, the counterflow to the oscillating circuit of a high voltage is eliminated. The high voltage is blocked by the diode D1 and the absorber XI even when flows back, and the counterflow to the power source is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for directly applying a high voltage to water for ionization and atomizing the same by ultrasonic waves, and to a method for removing static electricity by contacting atomized ionized water with a charged substance.

[0002]

2. Description of the Related Art Faults and disasters caused by static electricity have become a problem in all industrial fields. As a countermeasure, a method of lowering the electric resistance value of the product material itself, a method of using an antistatic agent, a method of increasing environmental humidity, a method of using a voltage application type static eliminator, a method of using a self-discharge type static eliminator, A method using a radiation type static eliminator is known. Among these, voltage application type static eliminators that ionize air to neutralize charged objects are widely used because they can be applied to all industrial fields, are easy to handle, and are relatively inexpensive.

There are a DC high voltage type and an AC high voltage type as a voltage application type static eliminator for generating a corona discharge to ionize air. The DC type is applied because either positive or negative ions are generated. Since the range is narrow and there are drawbacks such that an object to be neutralized is charged in the opposite polarity due to excessive supply, an alternating current method is generally used. This type of static eliminator applies a commercial high-frequency AC voltage of several KV to the discharge electrode to generate corona discharge, and generates positive and negative air ions necessary for static elimination at intervals of 20 msec (50
In the case of Hz). However, in this method, there is a limit to the amount of ions generated within the safe range, the effective ion reachable distance is short, and the static elimination ability is halved when the distance from the charged substance is 3 cm or more, and almost no static electricity can be removed when the distance is 10 cm or more. There are drawbacks. Further, even if the separation distance is within 3 cm, non-uniformity in charge removal occurs during charge removal of a charged object moving at a speed of 30 cm / sec or more, and the effect becomes extremely small.

It is known that ionized air generated by electric discharge in air is brought into contact with vapor-like fine water droplets ejected from a nozzle to obtain charged vapor, which can be injected into a clean room to eliminate static electricity. (JP-A-5-47488
issue). This method uses a high-frequency AC power supply as high as 1 KHz and indirectly charges steam, resulting in high power consumption. Further, the discharge electrode is easily soiled and maintenance is difficult.

[0005]

On the other hand, in the production process, the movement speed has been increased with the improvement of the production efficiency, and the static elimination of the charged substance moving at high speed has been particularly desired.
The present invention, even if the distance between the static eliminator and the charged substance is large,
Alternatively, the purpose is to provide a static eliminator that can quickly eliminate static electricity even when a charged substance moves at a high speed. The purpose is to make the ions generated from the static eliminator not by air but as mist-like water droplets and by sufficient amount. Is to achieve.

Further, in order to generate the ionized fog, for example, even if a high voltage is directly applied to the stored water of a commercially available ultrasonic humidifier, it leaks to the driving power source to generate the ionized fog. I can't. The present invention is intended to provide an electric circuit for preventing leakage to a high-voltage driving power source directly applied to stored water.

[0007]

The present invention is an apparatus capable of generating ultrasonic waves by means of a reservoir container made of an insulator and a ceramic vibrator installed so as to be immersed in the reservoir water. AC / AC having a step-up function for generating a high-voltage AC of 4 to 10 KV and a step-down function for generating a low-voltage AC of 5 to 60 V on the secondary side, with an AC from a 240 V household or industrial power source as the primary side
It has a transformer, and the high-voltage AC is connected to the discharge electrode that enables the direct application of voltage to the stored water, while the low-voltage AC circuit obtained by the step-down function has a bridge diode that converts this to DC. An ultrasonic static eliminator having a transistor oscillation circuit that radiates an ultrasonic wave of 1.5 MHz or more by means of a piezoelectric electromagnetic vibrator existing in the stored water container using the direct current.

Further, according to the present invention, an alternating current from a home or industrial power source of 100 to 240 V is guided to the primary side of an AC / AC transformer having a step-up and step-down function, and a voltage of 4 to 10 KV obtained by the step-up function. It is obtained by applying a voltage directly to the stored water stored in an insulated container using high-voltage AC, while using the step-down function.
-60V low-voltage alternating current is converted into direct current using a bridge diode, and the direct current is used to radiate ultrasonic waves of 1.5 MHz or more with a combination of a transistor oscillation circuit and a piezoelectric electromagnetic vibrator present in the stored water. The static electricity removing method is characterized in that the stored water is made into ionized mist-like water droplets, and this is brought into contact with a charged substance.

The technical contents of the present invention will be described in detail below. The present invention directly applies a high voltage of alternating current to water stored in an insulated container to ionize the water and simultaneously atomize the water by ultrasonic vibration to generate an ionized mist (vapor). Although many atomizers that use pressurized air are used for atomization, in the present invention, atomization is performed by ultrasonic vibration. Atomization of water by ultrasonic vibration is applied to humidifiers, and the mechanism is generally to vibrate a ferrite or ceramic oscillator using a transistor oscillation circuit at high speed to generate mist-like vapor from the surface of water. It is what is generated. The size of the fog particles can be adjusted to 0.5 to 50 μm by the vibration frequency of the vibrator.

When a high-voltage alternating current from a separate power source is directly applied to the water stored in such a humidifier, the applied voltage flows backward from the driving power source for ultrasonic vibration, and the high voltage can be applied to the stored water. Absent. Normally, the driving power supply has a line filter for preventing backflow, but it is not useful for preventing backflow of a high voltage of several KV. Therefore, the atomized vapor is not ionized and the static elimination effect beyond mere humidification cannot be obtained. The present invention relates to the design of a circuit in which a high voltage current applied to stored water does not escape to a driving power source, which will be described with reference to FIG.

An AC (AC) power supply for home use or a 220 VAC power supply for a factory or the like is introduced to the primary side of the AC / AC transformer (T1) through a capacitor. This AC
The / AC transformer has a voltage raising (step-up) function and a voltage lowering (step-down) function, and the alternating current generated on the secondary side by step-up is a high voltage of 4 to 10 KV, which is directly applied to the stored water. It is connected to the discharge electrode for applying the voltage via a high voltage ZNR surge absorber Z2.
This surge absorber is installed for high voltage backflow prevention and safety measures. For example, E manufactured by Matsushita Electric Industrial Co., Ltd.
RZC07DK101 or the like is used. The container of stored water is made of an insulating material such as plastic so that there is no leakage through the container when a voltage load is applied. .

The alternating current generated on the secondary side by the step-down of the AC / AC transformer is 5 to 60 V, which is used as a driving power source for ultrasonic wave generation. First, it is guided to the bridge diode (D1) through the low voltage surge absorber (Z1) and rectified into direct current. The ceramic oscillator (UR) is a power transistor (Q1) switching operation, a diode D2, capacitors C5, C6, C8, a resistor R.
It oscillates and radiates ultrasonic waves by the oscillation circuit composed of 3 and R4. Since the ceramic oscillator itself has an insulating property, there is basically no backflow from the stored water to the high-voltage oscillation circuit, but even if there is any, an AC / DC conversion bridge diode (D1) and surge. It will not be blocked by the absorber Z1 and will not flow back to the AC100V or 220V power supply. Therefore, a ferrite oscillator or the like can also be used. The variable resistor VR1 can be changed semi-fixedly in the range of about 200 to 1 KΩ, and the frequency of the generated ultrasonic waves can be changed appropriately within a range of ± 10%, and is necessary. It can be installed according to your needs.

When the stored water to which a high-voltage AC current is applied is atomized by an ultrasonic vibrator, positively or negatively charged mist is generated. The fog formed in this way is much more power-consuming than the indirect method in which the air used in fields such as electrostatic coating is ionized by corona discharge and the droplets are ionized by this ionized air. It shows the amount of ionic charge, does not generate ozone, and can exhibit an excellent static elimination effect with an inexpensive device.

The water used in the apparatus of the present invention may be ordinary tap water having a resistivity of about 0.05 to 0.06 KΩ · m or ultrapure water having a resistivity of 30 to 200 KΩ · m depending on the purpose of use. Can be used. Tap water is sufficient when used in a normal room. However, since fungi and microorganisms may be generated in the stored water tank, it is necessary to wash it frequently to prevent this, or add water-soluble glass containing chemicals and silver ions to prevent the growth of bacteria. Is preferred.

The charge removal using the apparatus according to the present invention is suitable for removing surface charge of a film, paper, cloth, thread, etc., which is running by winding up and rolling back. Also suitable for neutralization and static elimination of static objects and objects that are subject to pressure, peeling and friction, for example, electrified vinyl plates that have been polished in a multi-stage hot press work for polishing hard vinyl chloride plates. ing. Examples of stationary objects include cartoons and animations in which film, paper, etc. are pasted in a dry room, which is very effective.
The water used at this time is tap water, and there is almost no chance that water droplets will be attached to the surface of the charged substance by the ionized mist. This is because the water particles are extremely fine due to ultrasonic vibration, and even if this static elimination method is used, the humidity change in the surrounding environment is minimal. However, if the substance to be neutralized is a substance that especially dislikes moisture, special consideration is required, such as using ultrasonic vibration at a particularly high frequency to generate a mist of finer particles, or performing a drying process immediately after the neutralization process. In some cases

Further, high-pressure washing water, seawater, spray of paint, etc.,
When steam, liquefied gas, condensed carbon dioxide, or other pressurized gas is discharged at high pressure from a nozzle or a flange, static electricity is generated due to friction, collision, and splitting, but the static eliminator of the present invention is used in such fields. Can also be applied. Furthermore, the present invention can be applied to static elimination of static electricity generated in the process of transferring powdered or granular material such as plastic powder, metal powder, grain, etc. by a duct, a conveyor or the like or charging it into containers. For example, a silicon wafer serving as a semiconductor substrate is washed with high-purity water under high pressure, but at this time, the wafer may be considerably charged. In order to neutralize such a charged object by the method of the present invention, it is necessary to use high purity water.

Since semiconductors such as ICs and LSIs extremely dislike dust and the like, their manufacture is performed in an air-conditioned clean room, and the great enemy here is the generation of static electricity. Semiconductor devices are becoming smaller and smaller, and air ionizers have been conventionally used because they are susceptible to static electricity, but the apparatus of the present invention can also be used in this field. However, if the water used at this time contains impurities, it will cause dust and dirt. Therefore, it is preferable to use water having a purity level of ultrapure water.

[0018]

According to the present invention, the ionized fog generated by a simple device with extremely small power consumption and a small size is used for removing static electricity from a charged object having a large separation distance or moving at a high speed, and a great effect can be obtained. To be There is also an advantage that ozone is not generated when the ionized fog is generated.

[Brief description of drawings]

FIG. 1 is an example of an electric circuit for driving a static eliminator of the present invention.

[Explanation of symbols]

 T1 AC / AC transformer Z Surge absorber D1 Bridge diode UR Power transistor C8 Aluminum electrolytic capacitor VR1 Variable resistance

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Claims (4)

[Claims] 1. A device capable of generating ultrasonic waves by means of a stored water container made of an insulator and a ceramic vibrator installed so as to be immersed in the stored water, which is a household or industrial power source of 100 to 240 V. AC is used as the primary side, and the secondary side has an AC / AC transformer with a step-up function that generates a high-voltage alternating current of 4 to 10 KV and a step-down function that generates a low-voltage alternating current of 5 to 60 V. Connected to the discharge electrode so that voltage can be applied directly to the stored water, on the other hand, the low voltage AC circuit obtained by the step-down function has a bridge diode that converts this to DC, and the converted DC is used to store the stored water. An ultrasonic static eliminator having a transistor oscillating circuit for radiating ultrasonic waves of 1.5 MHz or more by a piezoelectric electromagnetic vibrator existing in a container. 2. A circuit having a circuit for guiding high-voltage alternating current from an AC / AC transformer to a discharge electrode via a high-voltage surge absorber, and guiding low-voltage alternating current from the transformer to a bridge diode via a low-voltage surge absorber. The static eliminator according to claim 1. 3. A ceramic oscillator is used as the piezoelectric electromagnetic oscillator, and a variable resistor is incorporated in the oscillation circuit so that the emitted ultrasonic waves can be changed in the range of 1.55 to 1.8 MHz. Static eliminator 4. A high-voltage alternating current of 4 to 10 KV obtained from the step-up transformer is introduced by introducing an alternating current from a household or industrial power source of 100 to 240 V to the primary side of an AC / AC transformer having step-up and step-down functions. 5-60 obtained by applying a voltage directly to the stored water stored in the insulated container while using the step-down function
A low voltage AC of V is converted into a direct current by using a bridge diode, and the direct current is used to combine the transistor oscillation circuit with the piezoelectric electromagnetic vibrator existing in the stored water to obtain 1.5M.
A static electricity elimination method, characterized in that ultrasonic waves of Hz or higher are radiated to make stored water into ionized water droplets, which are then brought into contact with a charged substance.