JP2014035844A - Ion generator and neutralization apparatus including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a neutralization apparatus including a plurality of discharge electrodes, which exhibits excellent neutralization performance while ensuring balance of the neutralization speed and the amount of positive and negative ions during proximity use.SOLUTION: An ion generator includes a plurality of discharge electrodes 10 generating positive or negative ions, respectively, a fan 14 for blowing ions generated from the discharge electrodes 10 to the outside, and a metal mesh 15 arranged at an ion blowing port. The metal mesh 15 has a first mesh part N1, and a second mesh part N2 having a mesh wider than that of the first mesh part N1. The discharge electrode 10 is located at the first mesh part N1 in the projected state.

Description

  The present invention relates to an ion generator that generates positive ions and negative ions, and a static eliminator that removes the charge of an object charged by the ions.

  There are a wide variety of target technical fields using ion generators and their application fields (apparatuses). Mainly for industrial use, electrophotographic charging device, air disinfection, sterilization or deodorization device, electrostatic precipitator, ozone generator, electrostatic coating device, etc., for example, manufacturing process of liquid crystal display device and semiconductor device Is used as a static eliminator in order to prevent static electricity failure in a clean room.

  The static eliminator performs static elimination by ionizing surrounding air molecules by corona discharge and irradiating the charged object with the generated positive and negative ions. If the discharge amount of positive and negative ions is biased to either direction, the object may be charged instead. Therefore, the balance is adjusted so that the positive and negative ions are equal.

  In recent years, along with the space saving of the usage environment in which the static eliminator is used, it is required that the static eliminator can be used even in the state of being close to the object. However, when the static eliminator is brought close to the object, there is a problem that the object is charged by the electric field generated in the discharge electrode.

  Therefore, as shown in FIG. 7, the static eliminator 90 of Patent Document 1 includes at least one discharge electrode 91 for generating ions, a fan 92 for flying ions, and a case opening opened in the fan portion. A case 94 provided with a portion 93 and a guard portion 95 provided with a guard strip 95a for guarding the case opening 93 in a net-like manner, whereby the guard portion 95 is arranged so as to overlap each discharge electrode 91. An electric field blocking part is formed to prevent the object from being charged by the electric field of the discharge electrode 91.

  Further, in Patent Document 2, in an ionizer in which a metal mesh grid is provided at a nozzle opening that sprays ions in a spot manner, the grid mesh space ratio SR is set within a range of 35% to 65%. In addition to the balance, the static elimination ability is prevented from decreasing.

Patent No. 4290437 (registered on April 10, 2009) JP 2008-41345 (released February 21, 2008)

  However, in the static elimination apparatus 90 of patent document 1, it does not disclose how much the area of the guard part 95 that interrupts the electric field should be, and if the electric field interruption part is too large, the static elimination time becomes longer and the static elimination is performed. There was a problem that ability decreased.

  The ionizer of Patent Document 2 optimizes the grid space ratio SR in the spot-like nozzle openings, and can improve the ion balance with a relatively small object, but the object is large. On the other hand, for a static eliminator that discharges ions from a plurality of discharge electrodes, the space ratio SR of Patent Document 2 is not necessarily optimal, and there is a problem that the ion balance cannot be achieved due to a reduction in static eliminability. .

  The present invention has been made in view of the above-described problems, and the object thereof is to eliminate the charge removal speed and ion balance during close use in a charge removal device including a plurality of discharge electrodes, and is excellent in charge removal. It is to provide a static eliminator having performance.

  An ion generator according to the present invention includes a plurality of discharge electrodes that respectively generate positive or negative ions, a fan that blows ions generated from the discharge electrodes to the outside, and a metal net disposed at an air blowing port. The metal mesh has a first mesh portion and a second mesh portion that is wider than the first mesh portion, and the discharge electrode is located in the first mesh portion in the projected state. And

  Further, the discharge electrode is characterized by being positioned so as to overlap the line portion of the first mesh portion in the projected state.

  The discharge electrode is a needle-like electrode.

  Further, the tip of the needle-like electrode is positioned so as to overlap the line portion of the first mesh portion in the projected state.

  Further, the tip of the needle-like electrode is positioned so as to overlap the intersection of the first mesh portion in the projected state.

  In addition, the discharge electrodes are linearly arranged, and the metal mesh is characterized in that the first mesh portion and the second mesh portion are alternately arranged according to the arrangement of the discharge electrodes.

  The fan is a cross flow fan.

  The static eliminator includes any one of the above ion generators.

  ADVANTAGE OF THE INVENTION According to this invention, in the static elimination apparatus provided with the several discharge electrode, the balance of the static elimination speed at the time of near use and the amount of positive / negative ions can be ensured, and the static elimination apparatus provided with the outstanding static elimination performance can be provided. it can.

It is a schematic diagram for demonstrating the static elimination apparatus of this invention. It is a top view which shows the measurement conditions of the structure of a static elimination apparatus, and static elimination performance. It is a schematic diagram which shows the kind of metal net | network provided in a static elimination apparatus. 4 is a graph of ion balance and static elimination time of various metal nets shown in FIG. 3. It is a schematic diagram which shows the 1st mesh part N1 and the 2nd mesh part N2 of a metal net. It is a graph of the ion balance and static elimination time of various metal networks shown in FIG. It is a schematic diagram which shows the static elimination apparatus of patent document 1. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. As an example, a static eliminator that embodies the ion generator of the present invention is shown. In addition, each Example is shown as an example to the last, Comprising: The technical scope of this invention is not limited.

  FIG. 1 is a schematic diagram for explaining a static eliminator 100 of the present invention. As shown in FIG. 1, the static eliminator 100 of the present invention includes, as the discharge electrode 10, a discharge unit 11 having a needle electrode 10 a that generates positive ions and a needle electrode 10 b that generates negative ions. A high voltage circuit 12 for supplying a high voltage, a discharge unit 11 and a control circuit 13 for controlling the high voltage circuit 12 are provided.

  Moreover, the fan 14 for ventilating the positive / negative ion produced | generated by the discharge unit 11 toward a to-be-eliminated object, and the metal net | network 15 provided in the ion ventilation port of the discharge unit 11 are provided.

  In FIG. 1, the structure for measuring the static elimination performance of the static elimination apparatus 100 is shown together, and a charge plate 80 and a surface electrometer 81 for measuring the potential of the charge plate 80 are arranged in place of the static elimination object. ing. The charge plate 80 is a product made by TRECK, and has a 150 x 150 mm rectangular metal plate and has a capacitance of 20 pF.

  The static elimination performance of the static eliminator 100 is evaluated by measuring ion balance and static elimination time. In the ion balance, the charge plate 80 is once grounded and the surface potential is set to 0 V, and then the ion wind of the static eliminator 100 is applied to the charge plate 80 arranged at a predetermined position, and the charge amount is measured by the surface potential meter 81. It is determined by measuring. Moreover, the static elimination time measures the time which neutralizes the charge plate 80 from 1 kV to 100 V, and the time which neutralizes from -1 kV to -100 V, and calculates | requires the average value of both as static elimination time.

  FIG. 2 is a top view showing a method for measuring the static elimination performance of the static elimination device 100. As shown in FIG. 2, the static elimination performance is measured by disposing the charge plate 80 at a distance of 50 mm, 100 mm, and 300 mm from the static elimination device 100, and nine points (0 mm, 0 mm, The center of the charge plate 80 was moved to ± 50 mm, ± 100 mm, ± 150 mm, ± 200 mm), and the ion balance and static elimination time were measured including in-plane variations.

  In FIG. 2, the structure of the static eliminator 100 will be described in detail. The discharge unit 11 includes a pair of acicular electrodes 10 a that generate positive ions and acicular electrodes 10 b that generate negative ions as the discharge electrodes 10. Is provided. The acicular electrodes 10a and 10b use a DC system in which a high voltage pulse having the same polarity as the ions to be generated is applied. However, by switching the polarity at fixed time intervals and driving, one acicular electrode 10 It is also possible to use an AC system that alternately generates positive and negative ions. By using a plurality of discharge units 11, the discharge amount of the whole ions can be increased and the charge removal area can be increased. In such a case, the discharge units 11 are arranged side by side in the width direction of the air outlet of the charge removal apparatus 100.

  A fan 14 for discharging the generated positive and negative ions toward the object to be discharged is disposed behind the discharge unit 11, and in front of the discharge unit 11 from which the ions are released, is separated from the needle electrode 10. A metal net 15 is arranged. For example, a cross flow fan that generates a wide air flow according to the discharge units 11 arranged in parallel is suitable as the fan 14.

  The metal mesh 15 has, for example, a mesh portion formed by intersecting a plurality of conductors, and the tips of the needle-like electrodes 10a and 10b and the conductors constituting the mesh portion are projected and overlapped in the ion emission direction. Are arranged as follows. As a result, the electric field generated in the needle-like electrodes 10a and 10b is shielded by the conductive wire of the metal mesh 15 and does not leak to the outside, and positive and negative ions emitted from the needle-like electrodes 10a and 10b pass through the mesh portion of the metal mesh 15. Thus, the object to be neutralized can be irradiated. In addition, the metal net | network 15 can prevent that the discharge | released ion is absorbed and reduced by the metal net | network 15 by using it in the state which floated electrically, without connecting to a ground potential.

  FIG. 3 is a schematic view of A, B, and C metal nets 15 having different mesh sizes as viewed from the discharge electrode 10 side. The metal mesh 15 has a space portion in which the mesh portion is formed by combining the conductive wires 15a and 15b having conductivity such as aluminum and the horizontal conductive wires 15a and the vertical conductive wires 15b in a mesh shape. The material of the metal net 15 can be a material having a low electrical conductivity such as copper other than the above aluminum.

  As shown in FIG. 3, the metal mesh 15 of B or C is different from the metal mesh 15 of A in that the size of the mesh portion is changed by adding / thinning the horizontal conductor 15a or the longitudinal conductor 15b. ing. The size of the mesh portion of the metal mesh 15 can be defined by the space ratio SR obtained from the ratio of the spatial cross-sectional area of the mesh portion.

  The space ratio SR is calculated by (space cross-sectional area excluding wire diameter) / (space cross-sectional area including wire diameter) × 100 per square. In the metal net 15 of FIG. 3A, when the wire diameters of the conductors 15a and 15b are 0.7 mm and the distance between the conductors 15a and 15b is 7.0 mm, the space ratio SR of the metal net 15 of A is calculated from the above formula. Is 82%. Similarly, the metal mesh 15 of B has a space ratio SR of 67% by adding conducting wires 15a and 15b in the horizontal and vertical directions of the metal mesh 15 of A and narrowing the interval by half. is there. Further, the C metal net 15 has a space ratio SR of 89% by thinning the conductive wires 15b of the A metal net 15 and widening the horizontal interval four times.

  FIG. 4 is a graph showing the ion balance and static elimination time at each distance measured for a distance of 50 to 300 mm for three types of metal nets 15 of A to C having different space ratios SR indicating the size of the mesh part. It has become. In addition, ion balance has shown the average value of the measured value of nine points | pieces mentioned above.

  As shown in FIG. 4, when used at a short distance of 50 to 100 mm, the metal network 15 of B having a relatively small space ratio SR of 67% has the largest ion balance of −5.3 V to −11.1 V. It was found that the charge could not be removed sufficiently. It was also found that the metal mesh 15 of C having a relatively large space ratio SR of 89% could not be sufficiently neutralized because the ion balance was greatly shifted to -6.2 V at a distance close to 50 mm. The metal mesh 15 of A with a space ratio SR of 82% had a small ion balance of -3.2 V at a short distance of 50 to 100 mm, but still needed improvement.

  As for the static elimination time, ions become difficult to pass when the space ratio SR becomes small. Therefore, the neutralization time of the B metal net 15 is 0.1 to 0.2 compared to the A metal net 15 and the C metal net 15. Increased by about a second.

  As shown in FIG. 4, the ion balance becomes closer to 0 V and becomes better as the distance from the static eliminator 100 increases. This may be because positive and negative ions are agitated and the ion balance is stabilized as the distance increases. For this reason, in the metal net 15 of A in which the ion balance is relatively good, by increasing the space ratio SR of the mesh part away from the needle electrode 10, it passes through the mesh part away from the needle electrode 10. To increase the amount of ions released.

  FIG. 5 shows a metal mesh 15 of A provided with a first mesh portion N1 formed uniformly, and a first mesh portion N1 and a second mesh portion N2 having a larger mesh than the first mesh portion. The metal net | network 15 of D provided with is shown. Specifically, in the first mesh portion N1, the space ratio SR of both the A and D metal nets 15 is 82%, and the space ratio SR of the second mesh section N2 of the D metal net 15 is 88%. It is formed to become.

  When the intersection of the first mesh portion N1 is aligned with the tip of the needle electrode 10 (A, D), and the intersection of the first mesh portion N1 with respect to the tip of the needle electrode 10 The static elimination performance was examined at a distance of 50 to 300 mm in the case where the positions were shifted (A2, D2).

  FIG. 6 is a graph showing ion balance and charge removal time at a predetermined distance as charge removal performance. As shown in FIG. 6, the ion balance at a short distance of 50 mm and 100 mm is farther from the needle electrode 10 than the one (A, A2) in which the entire mesh portion of the metal net 15 has the same space ratio SR. It was found that the ion balance can be improved with the portion (D, D2) provided with the second mesh portion N2 having a large space ratio SR in the portion.

  In addition, the difference (D2) in which the space ratio SR of the second mesh portion N2 is increased with respect to the shift between the intersection of the metal mesh 15 and the tip of the needle electrode 10 is a uniform mesh portion (A2). It was found that there was less deterioration of ion balance than

  That is, by providing the second mesh portion N2 that is wider than the first mesh portion N1 at a portion away from the needle-like electrode 10, the amount of ions that pass through the second mesh portion N2 is increased. Therefore, the ion balance can be improved. Further, as the amount of ions released increases, as long as the tip of the needle electrode 10 and the line portion of the mesh portion overlap each other, even if the intersection of the tip of the needle electrode 10 and the mesh portion slightly deviates, the ion balance deteriorates. Since it can suppress, the static elimination apparatus 100 can be manufactured easily.

  Of course, by disposing the tip of the needle electrode 10 and the intersection of the metal mesh 15 so as to overlap, the electric field from the needle electrode 10 does not leak to the outside, and the charge is not induced in the object to be discharged, and the charge removal performance is improved. Can be effectively increased.

  From the above, the ion generator of the present invention includes a plurality of discharge electrodes 10 that respectively generate positive or negative ions, a fan 14 that blows the ions generated from the discharge electrodes 10 to the outside, and an ion blowing port. The metal mesh 15 has a first mesh portion N1 and a second mesh portion N2 wider than the first mesh portion N1, and the discharge electrode 10 is in a projected state. In the first mesh portion N1, the ion balance can be improved and the charge removal time can be shortened when used as a charge removal device, and a charge removal device with a high charge removal capability can be realized.

DESCRIPTION OF SYMBOLS 10 Needle-shaped electrode 11 High voltage pulse generation circuit 12 High voltage circuit 13 Control circuit 14 Fan 15 Metal network 80 Charge plate 81 Surface electrometer 100 Static elimination device N1 1st mesh part N2 2nd mesh part

Claims (8)

A plurality of discharge electrodes that respectively generate positive or negative ions;
A fan for blowing the ions generated from the discharge electrode to the outside;
An ion generator comprising a metal net disposed at the air blowing port of the ions,
The metal mesh has a first mesh portion and a second mesh portion having a larger mesh size than the first mesh portion,
The ion generator is characterized in that the discharge electrode is located in the first mesh portion in a projected state.   The ion generator according to claim 1, wherein the discharge electrode is positioned so as to overlap a line portion of the first mesh portion in a projected state.   The ion generator according to claim 2, wherein the discharge electrode is a needle electrode.   4. The ion generator according to claim 3, wherein a tip portion of the needle-like electrode is positioned so as to overlap a line portion of the first mesh portion in a projected state.   5. The ion generator according to claim 4, wherein a tip end portion of the needle-like electrode is positioned so as to overlap an intersection of the first mesh portion in a projected state.   2. The discharge electrode is arranged in a line, and the metal mesh has the first mesh portion and the second mesh portion arranged alternately according to the arrangement of the discharge electrode. To 5. The ion generator according to any one of 5 to 5.   The ion generator according to claim 6, wherein the fan is a cross flow fan.   A static eliminator comprising the ion generator according to claim 1.