Wide range static neutralizer and method
Static neutralization of a charged object is provided by generating, in an ionizing cell or module, an ion cloud having a mix of positively and negatively charged ions, and reshaping the ion cloud by redistributing the ions into two regions of opposite polarity by using a second voltage. The second voltage creates an electrical field, which is preferably located in the vicinity of the ion cloud. The redistribution of the ions increases the effective range in which available ions may be displaced or directed towards the charged object. The electrical field redistributes ions that form the ion cloud. Ion redistribution within the ion cloud occurs because ions having a polarity corresponding to the polarity of the second voltage are repelled from the electrical field, and ions having a polarity opposite from that of the electrical field are attracted to electrical field. Redistribution of the ions into two regions of opposite polarity in the ion cloud in turn reshapes the ion cloud so that a portion of the cloud corresponding to the repelled ions is displaced by ions attracted to the electrical field, thus enhancing the range in which the ions may be dispersed or directed. This manner of redistributing ions into two regions is sometimes referred to as “ion polarization” in the disclosure herein.
1. An apparatus for neutralizing an electro-statically charged object at a first position, comprising:
a first electrode for receiving a first voltage;
a second electrode separated from said first electrode by a gap of a selected dimension;
a third electrode for receiving a third voltage;
said first voltage for creating an ion cloud having positive and negative ions and a weighted center located at a selected position within said gap when said first voltage is applied to said first electrode and a reference voltage is applied to said second electrode;
said third voltage for redistributing said positive and negative ions when said third voltage is applied to said third electrode; and
wherein said first voltage has a first frequency, said third voltage has a second frequency, and wherein said first frequency is greater than said second frequency.
2. The apparatus of claim 1 , wherein said third electrode includes a surface exposed to said gap.
3. The apparatus of claim 1 , wherein said third electrode includes a surface having a center that is aligned with the center of said gap.
4. The apparatus of claim 1 , wherein said ion cloud is a bipolar ion cloud.
5. The apparatus of claim 1 , wherein said first electrode has a shape in the form of a filament.
6. The apparatus of claim 1 , wherein said first electrode includes a tapered end terminating in the shape of a point.
7. The apparatus of claim 1 , wherein said redistribution of said ions reshapes said ion cloud, causing a portion of said ion cloud to disperse closer to the first position.
8. The apparatus of claim 1 , wherein said third voltage includes a DC-offset.
9. The apparatus of claim 1 , wherein said first voltage has a frequency and amplitude that are selected so that said weighted center of said ion cloud is positioned at the approximate center of said gap.
10. An apparatus for neutralizing an electro-statically charged object at a first position, comprising:
a first electrode for receiving a first voltage;
a second electrode separated from said first electrode by a gap of a selected dimension;
a third electrode for receiving a third voltage;
said first voltage for creating an ion cloud having positive and negative ions and a weighted center located at a selected position within said gap when said first voltage is applied to said first electrode and a reference voltage is applied to said second electrode;
said third voltage for redistributing said positive and negative ions when said third voltage is applied to said third electrode; and
wherein said first voltage has a first frequency within the range of 1 kHz to 30 kHz and said second voltage includes a second frequency within the range of 0.1 Hz and 500 Hz.
11. An apparatus for neutralizing an electro-statically charged object at a first position, comprising:
a first electrode for receiving a first voltage;
a second electrode separated from said first electrode by a gap of a selected dimension;
a third electrode for receiving a third voltage;
said first voltage for creating an ion cloud having positive and negative ions and a weighted center located at a selected position within said gap when said first voltage is applied to said first electrode and a reference voltage is applied to said second electrode;
said third voltage for redistributing said positive and negative ions when said third voltage is applied to said third electrode; and
wherein said first voltage has a frequency and amplitude that are selected so that said weighted center of said ion cloud is positioned at the approximate center of said gap, said frequency and said amplitude selected using the equation:
V=u*F|G 2
where u is the average ion mobility of said positive and negative ions, F is said frequency, V is said amplitude and G is said selected dimension of said gap.
12. An apparatus for reducing an electrostatic charge on an object located at a first position, comprising:
a first electrode for receiving a first voltage;
a second electrode and third electrode for receiving a reference voltage, said second electrode separated from said first electrode by a first gap and said third electrode separated from said first electrode by a second gap;
said first voltage for creating a first set of positive and negative ions within said first gap and a second set of positive and negative ions within said second gap when said first voltage is applied to said first electrode;
a fourth electrode and a fifth electrode for receiving a second voltage; and
said second voltage for redistributing said first and second sets of positive and negative ions when said second voltage is applied to said fourth and fifth electrodes.
13. The apparatus of claim 12 , wherein said first electrode is an ionizing electrode, and said reference voltage is equal to ground and is used as a reference voltage for said first and second voltages.
14. The apparatus of claim 12 , wherein said fourth electrode includes a first surface facing said first gap and said fifth electrode includes a second surface facing said second gap.
15. The apparatus of claim 12 , wherein said fourth and fifth electrodes each has a center respectively aligned with the center of said first and second gaps.
16. The apparatus of claim 12 , wherein said first voltage includes a first frequency, said second voltage includes a second frequency, and wherein said first frequency is greater than said second frequency.
17. The apparatus of claim 12 , wherein said first voltage includes a first frequency within the range of 1 kHz to 30 kHz and said second voltage includes a second frequency within the range of 0.1 and 500 Hz.
18. An apparatus for neutralizing an electro-statically charged object located at a first position, comprising:
an ionizing electrode and a reference electrode spaced apart across a gap, said ionizing electrode for receiving a first voltage, and wherein said first voltage causes the generation of positive and negative ions substantially located at a selected position within said gap when said first voltage is applied to said ionizing electrode;
a polarizing electrode having a surface facing said gap and for receiving a second voltage, said second voltage for redistributing said positive and negative ions when applied to said polarizing electrode; and
wherein said first voltage alternates at a first frequency selected to be within the range of 1 kHz to 30 kHz and said second voltage alternates at a second frequency selected to be within the range of 0.1 Hz to 500 Hz.
19. The apparatus of claim 18 , wherein said first voltage alternates at a first frequency and said second voltage alternates at a second frequency.
20. The apparatus of claim 18 , wherein said redistributing causes a portion of said positive ions to disperse closer to the first position.
21. The apparatus of claim 18 , wherein said redistributing causes a portion of said negative ions to disperse closer to the first position.
22. The apparatus of claim 19 , wherein said ionizing electrode has the shape of a filament.
23. An apparatus for reducing an electrostatic charge on an object located at a first position, comprising:
a first electrode for receiving a first voltage;
a second electrode and third electrode for receiving a reference voltage, said second electrode separated from said first electrode by a first gap and said third electrode separated from said first electrode by a second gap;
said first voltage for creating a first set of positive and negative ions within said first gap and a second set of positive and negative ions within said second gap when said first voltage is applied to said first electrode;
a fourth electrode for receiving a second voltage and a fifth electrode for receiving a third voltage;
said second voltage for redistributing said first set of positive and negative ions when said second voltage is applied to said fourth electrode; and
said third voltage for redistributing said second set of positive and negative ions when said third voltage is applied to said fifth electrode.
24. The apparatus of claim 23 , wherein said first electrode is an ionizing electrode, and said reference voltage is equal to ground and is used as a reference voltage for said first and second voltages.
25. The apparatus of claim 23 , wherein said fourth electrode includes a first surface positioned to face said first gap and said fifth electrode includes a second surface position to face said second gap.
26. The apparatus of claim 23 , wherein said first voltage includes a first frequency, said second voltage includes a second frequency, and wherein said first frequency is greater than said second frequency.
27. The apparatus of claim 23 , wherein said first voltage includes a first frequency within the range of 1 kHz to 31 kHz and said second voltage includes a second frequency within the range of 0.1 and 500 Hz.
28. The apparatus of claim 23 , wherein said first voltage includes a first frequency, said second voltage includes a second frequency, and said third voltage includes a third frequency.
29. The apparatus of claim 23 , wherein said first voltage has a first frequency, said second voltage has a second frequency, and said third voltage has a third frequency; and wherein said first frequency is greater than said second and third frequencies.
30. The apparatus of claim 23 , wherein said second and third voltages respectively alternate at frequencies that are 180 degrees out of phase.
31. The apparatus of claim 23 , wherein said second and third voltages respectively have trapezium waveforms.
32. The apparatus of claim 23 , wherein said second and third voltages respectively have square wave waveforms.
33. The apparatus of claim 23 , wherein said first and second gaps are substantially equal and said first voltage has a frequency and a voltage, and said weighted centers of said first and second sets of positive and negative ions are positioned at the approximate centers of said first and second gaps, respectively, by selecting said frequency and said amplitude using the equation:
V=u*F|G 2
where u is the average ion mobility of said positive and negative ions, F is said frequency, V is said amplitude and G is said selected dimension of said first gap.