JPH0547488A - Static eliminator for clean room - Google Patents

Abstract

PURPOSE:To improve efficiency of a static elimination by atomizing ultra-pure water from a micro-nozzle to which AC high voltage is applied, and by having the atomized water current charged positively or negatively by streaming charging, and whereby injecting the atomized water current into the air in a clean room. CONSTITUTION:The air in a clean room C is cooled by a refrigerator 1, and condensed water is formed into ultra-pure water by a pure water manufacturing device 2, the ultra-pure water is atomized from a nozzle 4 through a pure water supply line 3 at a predetermined flow and water particle diameter. High frequency AC high voltage is applied from a high frequency AC power source 6 between the nozzle 4 and a ring electrode 5, and the atomized water particles are charged alternately to a positive or negative mode by streaming charging, and the water particles are evaporated into the air in the clean room C. The charged steam is in contact with a material easy to be charged in the clean room, and is thus neutralized by the electrostatic, and static is thus removed effectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clean room static eliminator for preventing electrostatic charge in a clean room.

[0002]

2. Description of the Related Art Conventionally, when manufacturing and processing precision electronic parts and high-purity materials in a clean room, these parts and materials are subjected to various operations such as transportation using a plastic tray. However, since plastic has a high resistance and is easily charged, if the potential becomes high due to charging, a short-circuit failure is likely to occur, which causes problems such as dielectric breakdown of precision parts and dust adhesion.

Therefore, it has been attempted to generate positive and negative ions by an ion generator to neutralize the charged material.

[0004]

By the way, this ion generator uses an AC discharge, and there is a problem that the metal component in the electrode jumps out into the air by the sputtering action and becomes fine metal powder. Then, Japanese Patent Laid-Open No. 1-2668
As disclosed in Japanese Patent Laid-Open No. 65, it has been proposed to cover the electrode surface with a dielectric such as glass to prevent the generation of metal powder.

However, the above-mentioned conventional example has a problem that the ionization efficiency is poor because the air is simply ionized.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide a static elimination device for a clean room which can efficiently eliminate static electricity.

[0007]

In order to achieve the above object, the present invention is designed to spray ultrapure water from a fine nozzle to which an alternating high voltage is applied, and positively and negatively charge the sprayed water flow by a flow charge in a clean room. It is intended to be injected into the air.

[0008]

According to the above construction, the ultrapure water is positively and negatively charged by the flow charging and is injected into the air in the clean room, so that various kinds of easily charged materials can be discharged.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a refrigerator, which cools the air in the clean room C and recovers the moisture in the air. Impurities are removed from the water by the pure water producing device 2, and ultrapure water is supplied to the nozzle 4 through the pure water supply line 3 and can be jetted from the nozzle 4. A ring electrode 5 is arranged around the tip of the nozzle 4, a high frequency AC power supply 6 is connected between the nozzle 4 and the ring electrode 5, and the nozzle 4 side is appropriately grounded 7.

Next, the operation of the embodiment will be described.

The air in the clean room C is cooled by the refrigerator 1, and the water condensed there is converted into ultrapure water by the pure water producing device 2, and the flow rate from the nozzle 4 through the pure water supply line 3 is, for example, 6 cc / min. And the water droplet diameter is about 10 μm. A high-frequency AC high voltage of 1 kHz and 10 kV is applied between the nozzle 3 and the ring electrode 5, and the ejected water droplets are alternately charged by the flow charging into positive and negative and are evaporated into the air in the clean room C. As a result, the charged vapor comes into contact with the material in the clean room C, which is easily charged, by its electrostatic force to be neutralized, and the charge is removed. As described above, by performing the static elimination with the water vapor, the efficient static elimination can be performed. In addition, the moisture in the clean room C is not affected by the moisture in the air in the clean room C being condensed and used.

FIG. 2 shows another embodiment of the present invention.

In FIG. 2, 10 is a large number of nozzle openings 11
Pure water is supplied to the nozzle box 10 from the pure water supply line 12 in the nozzle box. This pure water may be supplied by purifying water in the air in the clean room C as shown in FIG. 1, or may be supplied from another pure water producing apparatus.

Each nozzle port 11 of this nozzle box 10
A ring-shaped or rod-shaped electrode 13 is provided in the nozzle, and a high-frequency AC power supply 14 is connected between the electrode 13 and the nozzle box 10.

In the example of FIG. 2, since the nozzle box 10 is provided with a plurality of nozzle openings 11, the amount of positive and negative electrified water vapor can be increased.

In the embodiment shown in FIGS. 1 and 2, the nozzle 4 or the nozzle box 10 may be jetted by applying ultrasonic vibration. In this case, the ejected droplets can be made more uniform, and the amount of charge can be made uniform.

[0018]

In summary, according to the present invention, by charging ultrapure water positively and negatively by flow electrification and injecting it into the air in the clean room, it is possible to efficiently neutralize various easily charged materials. .

[Brief description of drawings]

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

FIG. 2 is a diagram showing another embodiment of the present invention.

[Explanation of symbols] 3 pure water supply line 4 nozzle 5 ring electrode 6 high frequency AC power supply C clean room

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Akira Shibuya 6-17-16 Higashi Narashino, Narashino City, Chiba Prefecture Asahi Kogyo Co., Ltd. Technical Research Institute (72) Hiroaki Abe 6-17-16 Higashi Narashino, Narashino City, Chiba Prefecture Issue Asahi Industry Co., Ltd. Technical Research Institute (72) Inventor Hitoshi Kono 6-17-16 Higashi Narashino, Narashino City, Chiba Prefecture Asahi Industrial Co., Ltd. Technical Research Institute (72) Inventor Shigeo Honda 6-17 Higashi Narashino, Narashino City, Chiba Prefecture No. 16 Asahi Kogyo Co., Ltd. Technical Research Center

Claims (1)

[Claims] 1. A static eliminator for a clean room, characterized in that ultrapure water is sprayed from a minute nozzle to which an alternating high voltage is applied, and the sprayed water flow is positively and negatively charged by flow electrification and injected into the air in the clean room.