JP2004214426A - Ultra-high-pressure deionized water cleaning apparatus with static charge removal function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent electrostatic damage to an electric circuit, which is generated on an object to be cleaned because of static electricity during pressure feeding and spraying of an deionized water in a cleaning apparatus wherein the deionized water is fed by pressure and sprayed and the mist hits the object for cleaning. <P>SOLUTION: A nozzle head 5 and its vicinity are electrically insulated from the earth, and they are charged in advance in a reverse polarity where the object 15 to be cleaned is charged by an internal application device 3, and then the surface potential of the object is controlled at less than potential where an electric circuit generated on the surface of the object is electrostatically damaged. In addition, the potential on the surface of the object is measured by a detector 2, and the charging potential of the object is controlled by a controller 12 so that it can be kept at zero or under a potential to prevent the electrostatic breakage. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
[Industrial applications]
The present invention relates to a cleaning method and a cleaning apparatus for cleaning an object to be cleaned by spraying pure water and hitting the mist against the object to be cleaned.
[0002]
[Prior art]
When pure water is pumped and sprayed, static electricity is generated at the time of pumping and spraying, respectively. The generated static electricity causes a spark discharge between the grounds, and the discharge noise causes malfunctions of the peripheral control device, charges the object to be cleaned, and causes a problem that the electric circuit generated on the surface of the object to be cleaned is electrostatically destroyed. Let it.
[0003]
Therefore, in order to prevent spark discharge, it has been common practice to construct the pumping / nozzle head portion and its vicinity to be grounded to the ground to discharge static electricity in advance.
[0004]
[Problems to be solved by the invention]
However, pure water charged in the state of mist sprayed from the nozzle head does not have a static elimination effect when grounded, and eliminates the inconvenience of charging an object to be cleaned and electrostatically destroying an electric circuit generated on the surface of the object to be cleaned. Not done.
[0005]
[Means for Solving the Problems]
In the fog sprayed from the nozzle head, both positively charged droplets and negatively charged droplets are mixed, but the object to be cleaned is charged to the potential with the larger number of both.
[0006]
Therefore, in order to solve the above-mentioned problem, if the electric charge having the opposite polarity to the electric charge of the object to be cleaned is charged before it becomes fog, as a result, the charged potential of the object to be cleaned can be reduced, and the object to be cleaned can be reduced. Electrostatic breakdown of the electric circuit generated on the surface can be prevented.
[0007]
In order to realize this, the nozzle head and its vicinity are electrically insulated from the ground, and the electric charge generated in advance on the surface of the object to be cleaned is charged with a charge of the opposite polarity to that of the object to be cleaned. The surface potential of the object to be cleaned is controlled to be lower than the potential at which electrostatic breakdown occurs.
[0008]
In addition, the potential of the surface of the object to be cleaned is measured, and control is performed so that the charged potential of the object to be cleaned can be maintained at a potential or less that can prevent electrostatic destruction.
[0009]
[Action]
The nozzle head and its vicinity are electrically insulated from the ground, and charged by the opposite polarity charge that offsets the amount of charge on the object to be cleaned caused by static electricity generated when the pure water is pumped and sprayed. Static electricity is removed below the potential at which an electric circuit generated on the surface of the object breaks down electrostatically.
[0010]
In addition, the potential of the surface of the object to be cleaned during the cleaning is detected by a detector, and the potential of the opposite polarity that offsets the charge amount is controlled, so that the surface potential of the object to be cleaned can be adjusted to a value lower than the potential at which the electric circuit causes electrostatic breakdown. I do.
[0011]
【Example】
An embodiment of the present invention will be described below.
FIG. 1 shows the configuration of an embodiment of the cleaning apparatus according to the present invention. The cleaning device comprises a pure water injection part 1, a detector part 2, and an internal application device part 3.
[0012]
The pure water jetting part 1 includes a nozzle head 4 and a resin nozzle head support rod 2 for fixing the nozzle head 4, and is connected to a high-pressure pump (not shown) by a high-pressure resin hose 3.
[0013]
The detector section 2 includes a detector 7, a coaxial cable 8 connecting the detector 7 and the electrode 9, and a surface voltmeter 10 for measuring the surface potential of the electrode 9.
[0014]
The internal application device portion 3 includes a controller 12 that controls the nozzle head 4 to apply a reverse polarity potential having the same value as the potential detected by the surface voltmeter 10 and a high voltage generator 11 that generates a reverse polarity potential. .
[0015]
The pure water jetting part 1, the object to be cleaned 15 and the detector 7 are installed inside the cleaning tank 13, and the surface voltmeter 10, the cleaning tank 13 and the controller 12 are grounded.
[0016]
In the cleaning device, a high-pressure pump (not shown) is supplied to the nozzle head 5 from the pure water supply direction 16 through the high-pressure resin hose 4 and atomized. At that time, static electricity is generated while pure water is being pumped from the high-pressure pump to the nozzle head 5 and at the time of spraying. In order to cancel the generated static electricity, the high-voltage generator 5 can prevent the electric circuit generated on the surface of the cleaning object 15 from being electrostatically damaged.
[0017]
In addition, the surface potential of the object 15 to be cleaned is monitored based on the potential detected from the detector 8 installed near the object 15 to be cleaned, and the measured potential is fed back to the controller 12 so that the surface potential of the object 15 to be cleaned is Is controlled to be 0.
[0018]
The detection of the potential from the detector 8 can be selectively performed continuously or at predetermined intervals.
[0019]
The surface potential of the article 15 to be cleaned can be detected by detecting the electric charge with a detector having a known capacitance in addition to the above-mentioned surface potentiometer, and calculating the electric potential from the relation of electric charge = capacitance × potential. it can.
[0020]
【The invention's effect】
As is apparent from the above description, the cleaning device according to the present invention can lower the charged potential of the object to be cleaned, and can perform cleaning without electrostatically destroying an electric circuit generated on the surface of the object to be cleaned. It can be carried out.
[Brief description of the drawings]
FIG. 1 shows the configuration of an embodiment of a cleaning apparatus.
DESCRIPTION OF SYMBOLS 1 Pure water injection part 2 Detector part 3 Internal application device part 4 Resin high pressure hose 5 Nozzle head 6 Nozzle head support rod 7 Detector to be cleaned 8 Coaxial cable 9 Electrode 10 Surface electrometer 11 High pressure generator 12 Controller 13 Cleaning tank 14 Ground 15 Object to be cleaned 16 Direction of pure water supply

Claims (3)

Pure water is sprayed, sprayed, and the mist is hit on the object to be cleaned. In the path for cleaning the object to be cleaned, the nozzle head to be sprayed and its vicinity are electrically insulated from the ground, and the surface charged by the mist is charged. A cleaning method and a cleaning apparatus for charging a charge having a polarity opposite to that of a cleaning object to a nozzle head electrically insulated from the ground and the vicinity thereof. 2. The cleaning method according to claim 1, wherein the charging potential is adjusted so that the potential of the object to be cleaned during and after the cleaning is close to 0V. 3. The cleaning apparatus according to claim 2, further comprising means for measuring a potential for measuring a charged potential of the object to be cleaned.

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