JP2008084789A - Static charge eliminator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely eliminate static electricity from a charged body away from a static charge eliminator. <P>SOLUTION: This static charge eliminator includes a nozzle to spray water toward the charged body by atomizing it, a means for ground connection of water sprayed from the nozzle, and an electrode disposed between the nozzle and the charged body and made of a conductive material connected to a power supply, and is structured so that charges in the charged body is neutralized by ions generated as atomized waterdrops obtained by inductively charging the atomized waterdrops sprayed from the nozzle to reverse polarity of the polarity of the electrode evaporates, and static electricity can be thereby eliminated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a static eliminator, and more particularly to a static eliminator that eliminates static electricity in all processes where static electricity is generated, such as production processes such as plastic processing / molding, printing, semiconductor device manufacturing, liquid crystal panel manufacturing, and gas station. In particular, the present invention relates to a device capable of simultaneously removing static electricity from a charged body existing in a wide space and humidifying to prevent generation of static electricity.

  Conventionally, static electricity has been generated in processes such as plastic processing / molding, printing, semiconductor device manufacturing, and liquid crystal panel manufacturing. The effects of this static electricity increase the defect rate of products, increase the time required for production, and reduce the quality of products. Since it appears as various obstacles such as a decrease in the motivation of workers, a static eliminator (ionizer) for neutralizing a charged object is used in a wide range of industrial fields.

As the above-mentioned static eliminator, the present applicant has previously provided a static eliminator capable of surely eliminating static electricity from a separated charged body in Japanese Patent Laid-Open No. 2005-78980 (Patent Document 1).
As shown in FIG. 10, the static eliminator includes a nozzle 1 for atomizing water and spraying it toward the charged body 2, and a corona discharger 3 for charging water droplets sprayed from the nozzle 1. The discharger 3 comprises a needle-like discharge electrode 3A and a ring-like counter electrode 3B disposed opposite to the discharge electrode 3A, and is ejected from the nozzle 1 by corona discharge between the discharge electrode 3A and the counter electrode 3B. The charged fine water droplets are used as the charged fine water droplets, and the charge of the charged body 2 can be neutralized by the ions generated as the charged fine water droplets evaporate.

  In the static eliminator of Patent Document 1, since the charged fine water droplets sprayed toward the charged body have a larger mass and much lower mobility than ions, scattering and recombination due to an electric field are unlikely to occur, and the ion density is attenuated. Therefore, it can be transported to the charged body with little loss. The sprayed charged fine water droplets are conveyed with high density to the evaporation point by the air flow, become ions (small ions and large ions) along with the evaporation, and remove the charge without wetting the charged body existing in the vicinity. be able to. Therefore, ions having a high density can reach not only the vicinity of the static eliminator but also a remote charged body, and the charged body can be discharged over a wide range of space.

JP 2005-78980 A

The static eliminator of Patent Document 1 has the above-described advantages, but generates a corona discharge between the needle-shaped discharge electrode and the ring-shaped counter electrode to form the fine water droplets as charged fine water droplets. Electrodes and ring electrodes and lead wires connected to these electrodes are required, and there is room for improvement in that the number of parts is large and the configuration becomes complicated.
Furthermore, the fine water droplets in contact with the needle-like discharge electrode are likely to be coarse water droplets. Therefore, it is necessary to provide a trap or the like for collecting the coarse water droplets, and there is room for improvement such as requiring a relatively high voltage. is there.

  The present invention has been made in view of the above points, and in a static eliminator that can reliably perform static elimination on a charged body at a remote location and can also humidify to suppress the generation of static electricity, the configuration is simplified. An object of the present invention is to provide a static eliminator capable of suppressing the generation of coarse water droplets and operating at a relatively low voltage.

In order to solve the above problems, the present invention provides:
A nozzle that atomizes water and sprays it toward the charged body,
Means for grounding water sprayed from the nozzle;
The electrode is disposed between the nozzle and the charged body, and includes an electrode made of a conductive material connected to a power source.
When the fine water droplets sprayed from the nozzle pass through the electrode, the charge of the charged body is neutralized with ions generated along with the evaporation of the fine water droplets that are induced and charged in the opposite polarity to the polarity of the electrode. There is provided a static eliminator characterized by having a configuration capable of eliminating static.

It is preferable that a ring-shaped electrode (hereinafter abbreviated as a ring electrode) is used as an electrode connected to the power source, and fine water droplets sprayed from the nozzle are passed through the ring electrode.
The electrode is not limited to the ring electrode, and the electrode may be disposed at a position where the fine water droplets generate induction charging. For example, the plate-shaped electrodes may be disposed so as to face each other, and further, vertically and horizontally. You may arrange | position an electrode, respectively.

Examples of means for grounding the water include the following (1), (2), and (3), and any configuration that can ground the water sprayed from the nozzles is acceptable.
(1) The nozzle is formed of a conductive metal material and the nozzle is grounded;
(2) The nozzle is formed of an insulating resin material, and the water pipe or the water storage tank is formed of a conductive metal and connected to the ground;
(3) Put the grounded electrode in water.

The electrodes are connected to a DC power supply, an AC power supply, or a pulse power supply.
As described above, the fine water droplets ejected from the nozzle are inductively charged in the opposite polarity to the voltage applied to the electrode when passing through the electrode, and thus when the electrode is connected to the positive side of the DC power source. Can be charged negatively and produce negatively charged ions. When a pulse power source or an AC power source that generates pulses on the plus side and the minus side is used, positive and negative ions can be generated alternately.

  As described above, since the static eliminator of the present invention employs the induction charging method, it is only necessary to provide an electrode on the ejection side of the nozzle as compared with the corona charging method disclosed in Patent Document 1, and the ring electrode and the needle electrode are arranged to face each other. The structure can be made simpler than the corona charging method that needs to be performed. Further, the applied voltage may be lower than that of the corona charging method, and furthermore, a structure in which water droplets sprayed from the nozzle do not directly collide with the electrode can be obtained.

  Also, in the case of the induction charging method of the present invention, similarly to the case of the corona charging method of Patent Document 1, the charged fine water droplets have a mass larger than that of only ions and have a much lower mobility. Can be transported to the charged body with little loss without attenuating the ion density. The sprayed charged fine water droplets are conveyed with high density to the evaporation point by the air flow, become ions (small ions and large ions) along with the evaporation, and remove the charge without wetting the charged body existing in the vicinity. be able to. Therefore, ions having a high density can reach not only the vicinity of the static eliminator but also a charged body at a remote position, and the charged body can be neutralized over a wide range of space.

In particular, ions generated by evaporation of charged fine water droplets have many components having lower mobility than ions generated by discharge. Therefore, a high ion density can be obtained not only in the vicinity of the evaporation point but also in a point farther than that. This is because even after the water droplets evaporate, the water clusters are ionized and water molecules are attached to the ions, so that the movement of the ions becomes worse and the diffusion of the ions into the air is suppressed. As a result, it is possible to remarkably enhance the charge removal capability at a distant point as compared with the conventional corona discharge ionizer.
Further, since the water is atomized and sprayed by the nozzle, the charged body can be humidified to the required humidity, and the generation of static electricity can be suppressed by this humidification effect.

  The distance from the nozzle nozzle to the electrode is appropriately set according to the amount of spray from the nozzle, the spray angle, and the like, but is preferably within 30 mm from the nozzle nozzle. If it is within 30 mm, it may be set to 0 mm by being attached to the nozzle nozzle.

In the static eliminator of the present invention, spray control means for controlling the spray amount of the nozzle,
A surface potentiometer for measuring the potential level of the surface of the charged body;
It is preferable to include an ion control device that is connected to the electrometer and controls the spray control means according to the potential level of the charged body to control the amount of ions and / or the ion balance reaching the charged body. .

  With the above structure, the surface potential meter constantly monitors the potential level of the charged body, and the voltage applied to the electrodes is controlled according to the potential level to increase or decrease the amount of ions generated, or to control the spray control means. By increasing or decreasing the amount of water droplets sprayed, the potential level of the charged body is fed back in real time to prevent excessive supply of ions, etc. Can be summed.

In the present invention, the charged fine water droplets that have passed through the electrode have no members that collide before reaching the charged body, and thus no coarse water droplets are generated. As a result, there is no need to provide a trap or the like for collecting coarse water droplets.
When fine water droplets pass through the electrode, the fine water droplets that come into contact with the electrode may become coarse, but if a duct is arranged in the spraying direction of the nozzle and the electrode is arranged in the duct, the fine water droplet will come into contact with the electrode. Roughened water droplets can be attached to the inner surface of the duct. Moreover, by allowing the spray from the nozzle to pass through the duct, the flow direction of the spray is regulated, and the spray can be efficiently sprayed toward the target charged body.

The nozzle may be either a two-fluid nozzle that mixes and sprays water and air or a one-fluid nozzle that sprays water. As these nozzles, nozzles for spraying fine particles having a spray particle size of 1 μm to 100 μm are preferably used.
In order to atomize the spray, a two-fluid nozzle is preferably used rather than a one-fluid nozzle.
As a nozzle having a spray particle size of 1 μm or more and 100 μm or less, a fluid is rotated and collided inside the nozzle to achieve a plurality of atomizations, and the nozzle is opposed to and mixed by external collision, for example, An ultra-fine spray nozzle described in JP-A-62-289257 provided by the applicant is preferably used. In addition, you may atomize by the ultrasonic atomization method.

As the nozzle, it is preferable to use a dry fog nozzle having a mean particle diameter of 1 μm or more and 10 μm or less, which is a two-fluid nozzle that sprays a mixed fluid of water and compressed air.
Since the spray particle diameter of the dry fog nozzle is ultrafine as described above, it is possible to reliably prevent the charged body from getting wet when the charged body is neutralized.

A nozzle attached to a humidifier may be used as the nozzle, which may be a humidifier with a charge eliminating function. In that case, the said electrode is arrange | positioned in the position close | similar to the injection port of a humidifier. Humidifiers are often attached to adjust the humidity in the atmosphere. If this humidifier is used to provide a static elimination function, the humidification function, which is one of the purposes of the static elimination apparatus of the present invention, can be sufficiently exhibited. And it becomes unnecessary to install both a humidifier and a static elimination apparatus, and it can aim at the cost reduction of an installation expense and effective use of space.
As the humidifier to which the two-fluid nozzle is attached, the humidifiers of Patent Nos. 2844370, 2843971 and 2633753 provided by the present applicant are preferably used.

When four nozzles are mounted 90 degrees apart from the humidifier housing, a duct is provided around each nozzle, or an all-around duct that surrounds all four nozzles is mounted, The electrodes are arranged in front of the ejection direction of each nozzle.
With this configuration, charged water droplets can be sprayed from one humidifier in the entire circumferential direction, and the charged bodies arranged in a wide range can be neutralized, and the air in the range can be maintained at a required humidity.
Moreover, it is good also as a structure which attached the said electrode on the support material connected with the housing of the humidifier, without providing the said duct.

As for the nozzle to be used, it is preferable that the spray flight distance from the injection port is 1 meter or more and 5 meters or less.
The longer the spray flying distance from the nozzle (the distance at which the water droplets evaporate), the more the charged body at a distant position can be neutralized, so one meter or more is necessary. On the other hand, if the fluid pressure supplied to the nozzle is high, the spray flight distance can be extended to some extent, but it is easy to evaporate to atomize the spray, and it is practically difficult to set it to 5 meters or more. by.

When a blower device such as a blower fan is disposed upstream of the nozzle and an air flow that transports water droplets sprayed from the nozzle is generated, the flight distance of the water droplets can be extended to 10 meters.
Thus, in addition to the spraying force by the nozzle, the charged fine water droplets can be transported also by the air flow generated by the blower device, and the ions can be quickly delivered to the charged body in the distance.

As is clear from the above description, in the static eliminator of the present invention, water is ejected from a grounded nozzle to form water droplets that are induction-charged with a reverse polarity with respect to the voltage applied to the electrodes. Can be suppressed. As a result, high-density ions can be supplied to a point away from the static eliminator, and the charge bodies existing in a wide range can be neutralized. Moreover, if spraying is performed so that the arrival area of the charged fine water droplets is limited, the charged body in a specific area can be discharged while being away from the charge removal apparatus. Furthermore, since ions are scattered from the air, even a charged body with unevenness can be uniformly discharged.
In addition, the humidifying function by spraying water droplets from the nozzle has an effect of preventing the generation of static electricity, and a cooling effect by evaporation of the water droplets can also be expected. Further, by using a blower fan or the like that generates an air current, it is also possible to remove static electricity from a farther charged body.

Embodiments of the present invention will be described with reference to the drawings.
1 to 3 are schematic views of a static eliminator 10 according to the first embodiment.
A so-called dry fog nozzle that sprays fine water droplets having an average particle diameter of 1 μm to 10 μm and evaporates all the sprayed water droplets 30 in the atmosphere is used as the nozzle 11.
The nozzle 11 is a two-fluid nozzle that ejects a mixed fluid of compressed air and water. The nozzle 11 is supplied with compressed air from an air compressor 17 connected via a gas supply pipe 19 and water from a water supply device 18 connected via a water supply pipe 20.
The nozzle 11 of the present embodiment has a spray amount of 0.5 liter / H or more and 5 liter / H or less.

The nozzle 11 is formed of a conductive metal material, and a conductive wire 100 is connected to the nozzle 11, the conductive wire is grounded, and water passing through the nozzle 11 is grounded.
The nozzle 11 is disposed in a straight tubular duct 36 made of an insulating material, and the duct 36 extends from the injection port 11a of the nozzle 11 in the spraying direction and is disposed toward the charged body 28 side. The charged body 28 is disposed within 3 m from the nozzle 11. The duct 36 only needs to guide spraying to the charged body 28 and does not need to extend to the charged body 28.

  Further, a blower fan 22 is installed behind the nozzle 11, that is, on the side opposite to the injection direction to increase the flow rate of the spray sprayed from the nozzle 11 to the duct 36.

In the duct 36, a ring electrode 21 is arranged in a range of 0 mm to 30 mm in the spraying direction from the injection port 11 a of the nozzle 11, and the ring electrode 21 is connected to the DC, AC, or pulse type high-voltage power source via the conductor 101. 24 is connected. In the present embodiment, a DC power supply is used as the high-voltage power supply 24, and a voltage of 1 KV to 3 KV can be applied.
In the present embodiment, the ring electrode 21 has an inner diameter of 50 mm, an outer diameter of 50 mm, and a ring thickness of 10 mm.

When an alternating high voltage is applied to the ring electrode 21, positive and negative ions are periodically generated, and ions of opposite polarity neutralize the charge of the charged body 28 according to the charged polarity of the charged body 28. That is, the charged body 28 is not charged with a reverse polarity with respect to the initial charge.
However, since the generation of ions becomes periodic when an AC high voltage is applied, the static elimination capability is lower than when a DC high voltage is applied when the same applied voltage is applied.

The nozzle 11 composed of a dry fog nozzle has the configuration shown in FIG. The nozzle 11 has a pair of nozzle heads 13, 14 that are inclined and opposed to the tip of the nozzle body 12, and mist sprayed from the spray holes 15, 16 of the nozzle heads 13, 14 is mixed by collision. Drops are super atomized. The nozzle body 12 is formed with an air guide path 42 and a liquid guide path 41 for introducing compressed air and water into the nozzle heads 13 and 14. Nozzle tips 46 are accommodated in the nozzle heads 13 and 14 and fixed by plugs 43, and the tips of the nozzle tips 46 protrude from the nozzle heads 13 and 14 to form the injection holes 15 and 16.
The water passing through the liquid guide path 41 flows through the center hole 45 of the plug 43 and the liquid hole 47 of the nozzle tip 46, while the compressed air passing through the air guide path 42 flows through the air ejection path 48 on the outer periphery of the nozzle tip 46, As shown in FIG. 3, the mist mixed and sprayed from the injection holes 15 and 16 is further collided and atomized outside the nozzle to generate fine mist having an average particle diameter of less than 10 μm that does not wet the surface of the object.

  Furthermore, the static eliminator of this embodiment includes a spray control means 23 provided in the water supply pipe 20, a non-contact surface potential meter 26 that measures the potential level of the charged body 28 in a non-contact manner, and a non-contact surface potential. An ion controller 25 connected to the total 26 and connected to the high voltage power supply 24 and the spray control means 23 is provided.

When the ion control device 25 receives the potential level of the surface of the charged body 28 measured by the non-contact surface potential meter 26 and determines that the supply amount of the ions 32 to the charged body 28 is excessive, the ion control device 25 The voltage applied to the ring electrode 21 from the power supply 24 is lowered, and / or the amount of water droplets sprayed from the nozzle 11 by the spray control means 23 is reduced to reduce the supply amount of ions 32. On the other hand, when it is determined that the supply amount of the ions 32 to the charged body 28 is small, the voltage applied to the ring electrode 21 is increased from the high voltage power source 24 and / or sprayed from the nozzle 11 by the spray control means 23. The amount of supplied water droplets is increased to increase the ion supply amount.
When the power supply voltage is an alternating current or a pulse, the amount of ions and the positive / negative ion balance are controlled by controlling the positive / negative peak voltage or duty ratio of the alternating current to minimize the residual charge of the charged body.

Next, the operation of the static eliminator 10 will be described.
The nozzle 11 is supplied with compressed air from the air compressor 17 through the gas supply pipe 19 and is supplied with water from the water supply device 18 through the water supply pipe 20, thereby opposing the injection holes 15, The mist ejected from 16 is collided and diffused, and ultrafine atomized water droplets 30 having an average particle diameter of 1 μm to 100 μm float in the duct 36 downstream. At that time, the fine water droplets 30 flow through the duct 36 at a higher speed by the air blown from the blower fan 22.

The minute water droplets 30 ejected from the nozzle 11 are grounded by the time they are ejected from the nozzle. The fine water droplets 30 pass through the inside of the ring electrode 21, and at that time, the charged fine water droplets 31 are formed by induction charging with a polarity opposite to the voltage applied to the ring electrode 21.
The charged fine water droplets 31 evaporate into the ions 32 while moving through the space, but no charge is lost in the process until the charged fine water droplets 31 evaporate. Therefore, the evaporation distance in the case of the dry fog nozzle 11 is typically about 2 to 3 m from the injection holes 15 and 16, so that the charge can be carried with a small loss from the nozzle 11 to at least about 3 m. Therefore, as described above, the charged body 28 is disposed within 3 m from the nozzle 11.

As described above, the ultrafine charged fine water droplets 31 sprayed from the nozzle 11 evaporate, and the ions 32 generated by the evaporation reach the surface of the charged body 28, thereby neutralizing the static electricity on the surface of the charged body 28. And can be neutralized. Many of the ions 32 generated by the evaporation of the charged fine water droplets 31 are large ions having lower mobility than the ions generated by the corona discharge described in Patent Document 1, so that the ions 32 are scattered or recombined. The attenuation of the ion density is reduced, and effective neutralization is possible even at a point 3 to 5 m away from the dry fog nozzle 11. Moreover, since the water atomized by the dry fog nozzle 11 is sprayed, the effect which prevents the generation | occurrence | production of static electricity by the humidification effect is also acquired.
When the charging polarity of the charged body 28 is clear, a high voltage having the same polarity as that of the charge on the surface of the charged body 28 is applied to the ring electrode 21 to generate reverse polarity ions and It is better to neutralize the charge.

  In this case, during the static elimination operation, the potential level on the surface of the charged body 28 is always measured by the non-contact surface potential meter 26. When the ion controller 25 receiving this measurement value determines that the supply amount of the ions 32 to the charged body 28 is excessive, the voltage applied to the ring electrode 21 is decreased by controlling the high-voltage power supply 24. The amount of electric charges discharged is reduced to reduce the amount of charge on the fine water droplets 30, and the ions 32 generated by the evaporation are reduced.

  Further, the supply amount of the ions 32 may be reduced by reducing the amount of the charged fine water droplets 31 by controlling the spray control means 23 to reduce the amount of the fine water droplets 30 sprayed from the nozzle 11. As described above, the ion control device 25 may control either the high-voltage power supply 24 or the spray control means 23 to control the supply amount of the ions 32. The supply amount may be controlled.

On the other hand, when the ion controller 25 receives the measurement value from the non-contact surface potential meter 26 and determines that the supply amount of ions 32 to the charged body 28 is small, the high voltage power source 24 is controlled to control the ring electrode 21. The voltage applied to is increased, the charge amount is increased to increase the charge amount to the fine water droplets 30, and the amount of ions 32 generated by the evaporation is increased.
Further, by controlling the spray control means 23 to increase the amount of the fine water droplets 30 sprayed from the nozzle 11, the charged fine water droplets 31 may be increased and the ions 32 generated by the evaporation may be increased.

  Furthermore, since the blower fan 22 is provided behind the nozzle 11, it is possible to generate an air flow that quickly conveys the fine water droplets 30 sprayed from the nozzle 11. That is, the time during which the fine water droplets 30 and the charged fine water droplets 31 evaporate is almost determined when the conditions such as the average particle diameter and the humidity are the same. By carrying it far, ions 32 can reach far away charged body 28.

4 and 5 show a second embodiment.
The difference from the first embodiment is that a humidifier 29 including a nozzle 57 for spraying dry fog is used instead of using the nozzle 11 alone.
As the humidifier 29, the one described in Japanese Patent No. 2843970 filed earlier by the present applicant is used. Specifically, as shown in FIG. 5A, the casing 51 is formed by a casing main body 53 and an upper lid 52, and has a water storage chamber 54 therein, and is loosely fitted into the inner surface of the water storage chamber 54 so as to move up and down according to the amount of water stored. A float 61, a water stop valve 59 that opens and closes a liquid flow path that is attached to the upper lid 52 and communicates with the water storage chamber 54, is rotatably supported on the inner surface side of the upper lid 52, and a tip is brought into contact with the float A water stop lever 60 that moves the water stop valve 59 up and down in accordance with the principle of leverage in conjunction with the raising and lowering of the float 61, a liquid absorption pipe 62 that passes through the center through hole of the float 61 to the lowest end of the water storage chamber 54, A nozzle 57 disposed on the upper surface of the upper lid 52 and communicating with the gas introduction pipe 55 and the liquid absorption pipe 62 is provided.

As shown in FIG. 5 (B), the nozzle 57 includes an air passage 57b and a liquid passage 57c branched in two directions by a body 57a, a tip attachment portion 57d formed so as to face each other, and a tip attachment portion. And a nozzle chip 63 fitted into the front end side of 57d.
Air and water are mixed in the tip mounting portion 57d, and the mist sprayed from the injection hole 57e at the tip of the nozzle tip 63 is collided and mixed outside the nozzle to spray the ultrafine mist.
Other configurations and operational effects are the same as those of the first embodiment, and thus description thereof is omitted.

In the case where the nozzles 57 are arranged at an interval of 90 degrees on the outer periphery of the casing of the humidifier 29, ducts 36A ′ to 36D ′ are respectively provided on the outer periphery of the nozzles 57 as shown in FIG. The ring electrode 21 may be disposed in each duct. Further, as shown in FIG. 6B, a ring 36 ′ having an annular cross section surrounding the entire outer periphery may be attached, and the ring electrode 21 may be disposed in front of the nozzle nozzle.
Thus, if it is set as the structure which can inject a charged water droplet in multiple directions, it will be possible to perform static elimination of a charged body and adjustment of humidity in a wide range.

  In the first embodiment and the second embodiment, the nozzle 11 is formed of a conductive metal material and the nozzle 11 is grounded. However, the water supply pipe 20 and / or the water supply device 18 including the water storage tank is electrically conductive. It may be formed of a conductive metal material and grounded. Or you may throw in the electrode which carried out the earth connection in water.

Hereinafter, the following Experiment 1 to Experiment 3 were performed for the first embodiment.
[Experimental Example 1]
In Experiment 1, the space charge density at a position 2 m away from the nozzle 11 was measured by changing the distance between the nozzle 11 and the ring electrode 21.
The air supplied to the nozzle 11 has an air flow rate of 37 mL / min from the air compressor 17 and a water supply flow rate of 0.5 mL / s from the water supply device 18. An inner diameter of 30 mm, an outer diameter of 50 mm, and a thickness of 20 mm were used as the ring electrode 21, and a voltage of −3 kV was applied to the ring electrode 21. The wind speed from the blower fan 22 was 4.4 m / s.
The distance between the nozzle 11 and the ring electrode 21 was changed to 0 mm, 10 mm, 20 mm, and 30 mm, and the relationship with the space charge density at a position 2 m away from the nozzle 11 was measured. The space charge density was measured using a suction type Faraday gauge having a cotton-like filter made of fine metal wires inside. As a result, as shown in FIG. 7, it was confirmed that the space charge density increased as the ring electrode 21 approached the nozzle even at a position 2 m away.

[Experiment 2]
In Experiment 2, the voltage applied to the ring electrode 21 was changed, and the space charge density at a position 2 m away from the nozzle 11 was measured.
The distance between the nozzle 11 and the ring electrode 21 was 2 mm. The air and water supplied to the nozzle 11 were the same as in Experiment 1. The shape of the ring electrode 21 was also the same as in Experiment 1, and the wind speed from the blower fan was also the same. The space charge density was measured from the nozzle 11 by changing the voltage applied to the ring electrode 23 from 0 to −6 KV. As a result, as shown in FIG. 8, the space charge density was the highest when it was −3 KV.

[Experiment 3]
In Experiment 3, the size of the ring electrode 21 was changed, and the space charge density at a position 2 m away from the nozzle 11 was measured.
The distance between the nozzle 11 and the ring electrode 21 was 2 mm, and a voltage of −3 KV was applied to the ring electrode 21. The air and water supplied to the nozzle 11 were the same as in Experiment 1, and the wind speed from the blower fan was also the same.
As the ring electrode 21, a small ring having an inner diameter of 30 mm and an outer diameter of 50 mm and a large ring having an inner diameter of 50 mm and an outer diameter of 70 mm were used.
As a result, as shown in FIG. 9, the space charge density was larger when the small ring was used.

It is a block diagram of the static elimination apparatus of 1st Embodiment of this invention. It is principal part sectional drawing of a dry fog nozzle. It is a principal part enlarged view which shows the injection condition of a dry fog nozzle. It is a block diagram of the static elimination apparatus of 2nd Embodiment. (A) is sectional drawing of a humidifier, (B) is principal part sectional drawing. (A) (B) is a schematic plan view which shows the modification of 2nd Embodiment. 6 is a graph showing the results of Experiment 1. 10 is a graph showing the results of Experiment 2. 10 is a graph showing the results of Experiment 3. It is drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Static elimination apparatus 11 Nozzle 12 Nozzle main body 13, 14 Nozzle heads 15, 16 Injection hole 17, 33 Air compressor 18 Water supply apparatus 19 Gas supply pipe 20 Water supply pipe 21 Ring electrode 22 Blower fan 23 Spray control means 24 High voltage power supply 25 Ion control device 26 Non-contact surface potential meter 28 Charged body 29 Humidifier 30 Water droplet 31 Charged fine water droplet 32 Ion 36 Duct

Claims (10)

A nozzle that atomizes water and sprays it toward the charged body,
Means for grounding water sprayed from the nozzle;
The electrode is disposed between the nozzle and the charged body, and includes an electrode made of a conductive material connected to a power source.
Neutralizes the charge of the charged body and neutralizes the charge with ions generated by evaporation of the fine water droplets sprayed from the nozzle and induced and charged to the fine water droplets with the opposite polarity to the polarity of the electrodes when passing through the electrodes. A static eliminator characterized by comprising.  2. The static eliminator according to claim 1, wherein the electrode connected to the power source is a ring electrode, and fine water droplets sprayed from the nozzle are passed through the ring electrode. The static eliminator according to claim 1 or 2, wherein the means for grounding the water comprises the following (1), (2), or (3).
(1) The nozzle is formed of a conductive metal material and the nozzle is grounded;
(2) The nozzle is formed of an insulating resin material, and the water pipe or the water storage tank is formed of a conductive metal and connected to the ground;
(3) Put the grounded electrode in water.   A DC power supply, an AC power supply or a pulse power supply is connected to the electrode, and when the spray amount of the nozzle is 0.5 liter / H or more and 5 liter / H or less, a voltage of 1 to 3 KV from the power supply to the electrode The static elimination apparatus of any one of Claim 1 thru | or 3 which has applied.   The static elimination apparatus of any one of Claim 1 thru | or 4 which has arrange | positioned the said electrode in the position within 30 mm from the injection nozzle of the said nozzle. Spray control means for controlling the spray amount of the nozzle;
A surface potentiometer for measuring the potential level of the surface of the charged body;
An ion control device that is connected to the electrometer and controls the spray control means according to the potential level of the charged body to control the amount or / and ion balance of ions reaching the charged body. The static eliminator according to claim 1.   7. The nozzle according to claim 1, wherein the nozzle is composed of a two-fluid nozzle that sprays and mixes water and air, or a one-fluid nozzle that sprays only water, and the spray particle size is 1 μm or more and 100 μm or less. The static elimination apparatus of description.   8. The static eliminator according to claim 1, wherein the nozzle comprises a two-fluid nozzle that mixes water and compressed air and sprays it as dry fog having an average particle diameter of 1 μm to 10 μm.   9. The static eliminator according to claim 1, wherein the nozzle is a nozzle attached to a humidifier, and the electrode is disposed within a range of 30 mm from an injection port of the humidifier.   The static elimination apparatus of any one of Claim 1 thru | or 9 provided with the air blower which blows off the spray from the said nozzle through the said electrode to the said charging body.

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