JP6168979B2 - Filter charging device and filter charging method - Google Patents

Description

  In the electret filter used in the air conditioner, when the dust is reused by washing after dust collection for a certain period, the electret characteristics deteriorated by use and washing are regenerated and the dust collecting rate is recovered. The present invention relates to a filter charging processing apparatus and a filter charging processing method.

  A non-woven electret filter is used as a medium performance filter for air conditioning. Non-woven electret filters have an electric polarization oriented and fixed inside and on the non-woven fibers, and in addition to aerodynamic collection mechanism, due to the effect of electrostatic force, excellent dust despite low pressure loss Realize the collection rate.

  In the non-woven electret filter, the sheet-like non-woven filter medium is charged under a corona discharge in the atmosphere at the time of manufacture to keep the electric polarization in the filter medium. In general, electret filters are used by attaching a thin and thin fiber electrified filter medium to a thick aggregate with structural support by bonding, heat melting, mechanical frictional force, etc. The aggregate on the back surface generally has a relatively low surface resistivity, so that it cannot hold a charged charge and is difficult to charge.

  In addition, the sheet-shaped filter medium that has been charged is folded into a pleat shape and processed into a three-dimensional shape in order to increase the surface area of the filter medium for the purpose of reducing pressure loss when inserted into a predetermined duct opening after bonding. Often. At this time, in order to maintain a three-dimensional shape, fixing means such as adhesion by an adhesive (hot melt) is generally taken.

  By the way, an uncharged non-woven filter removes dust adhering during use by washing with water, etc., so that the dust collection rate is recovered and can be reused. However, in the case of an electret filter, Since the electric polarization is lost due to the influence of the surfactant or the like contained in the cleaning agent, the collection rate is lowered. Therefore, in order to recover the initial collection rate, it is necessary to recharge the filter medium.

  As a conventional recharging technique, a method has been proposed in which a washed electret material is brought into close contact with a corona discharge electrode and introduced into an electric field in a flat state (see, for example, Patent Document 1).

  As another conventional recharging technique, there has been proposed a method in which a three-dimensional filter is irradiated with plasma in a vacuum to be recharged (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 3-105907 JP 2003-210924 A

However, the prior art has the following problems.
When charging a three-dimensional filter folded in a pleat shape by the charging method of Patent Document 1 or Patent Document 2, when charged particles for charging are injected from the discharge, the surface on which the charged particles of the filter are injected On the side, the charged particles stay first to form a reverse electric field, and the charged particles injected later are prevented from entering the interior of the three-dimensional shape, so that it is difficult to charge the valley portion of the pleated shape. For this reason, the charging of the entire filter greatly loses uniformity, and the recharged state similar to that at the time of initial manufacture is not reproduced, and the desired collection performance cannot be obtained.

  In Patent Document 1, a three-dimensional filter is not intended. However, if the method of Patent Document 1 is to be used for a three-dimensional filter, the filter is previously used when the used and washed electret filter is regenerated. After the sheet is developed, corona discharge is performed so that charging is applied to the entire filter surface.

  However, the adhesive part for maintaining the three-dimensional pleat shape of the filter is destroyed and the filter frame for attachment to the duct is destroyed / removed. Since the disassembly / assembly process is repeated, there is a problem that the cost merit of reusing the three-dimensional electret filter is almost lost.

  When using the method of Patent Document 2, since a vacuum is required, a vacuuming step and an air release step are required before and after the recharging process. When applied to a large amount of filter processing, the throughput of continuous processing is increased. Greatly limited. In addition, in order to recharge a large amount of filter at once by batch processing, a large-capacity vacuum chamber and a plurality of plasma electrodes are required, and both introduction cost and operation cost are extremely large. There is also.

  The present invention has been made to solve the above-described problems. When charging a filter, charged particles can reach the deep part of a three-dimensional filter to uniformly charge the entire filter. An object of the present invention is to obtain a filter charging device and a filter charging method.

The filter electrification processing apparatus according to the present invention includes a pair of perforated electrodes and a plate-like drift electrode, and forms a drift electric field between the perforated electrode and the drift electrode by applying a voltage to the drift electrode . An electrode and a charged fine particle generation unit that generates and supplies charged fine particles having a smaller specific charge than electrons and ions to the drift electric field. The filter is charged by irradiating the drifted charged fine particles.

The filter charging method according to the present invention includes a holed electrode and a plate-like drift electrode, and forms a drift electric field between the holed electrode and the drift electrode by applying a voltage to the drift electrode. An electric field forming step, a generation step for generating charged fine particles having a specific charge smaller than that of electrons and ions, a supply step for supplying charged fine particles to a drift electric field, and a filter to be processed installed between the electrodes, A charging step of charging the filter by irradiating the charged fine particles drifted by the drift electric field.

According to the filter charging apparatus and the filter charging method according to the present invention, charged fine particles having a specific charge smaller than that of electrons and ions are generated, and the charged fine particles are drifted by a drift electric field. Charge the filter.
Therefore, when charging the filter, the charged particles can reach the deep part of the three-dimensional filter, and the entire filter can be uniformly charged.

It is sectional drawing which shows the structure of the filter electrification processing apparatus which concerns on Embodiment 1 of this invention. (A) is a perspective view which shows the structure of the washing | cleaning medium performance filter which concerns on Embodiment 1 of this invention, (b) is the side view which looked at the pleat from the side. In Embodiment 1 of this invention, it is a schematic diagram explaining the principle in which charging is inhibited. In Embodiment 1 of this invention, it is a schematic diagram explaining the principle in which uniform charging is promoted. It is explanatory drawing which shows the effect of the charge in the filter charge processing apparatus which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the structure of the filter electrification processing apparatus which concerns on Embodiment 2 of this invention. It is sectional drawing which shows the structure of the filter electrification processing apparatus which concerns on Embodiment 3 of this invention.

  Hereinafter, preferred embodiments of a filter charging device and a filter charging method according to the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts will be described with the same reference numerals. .

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing a configuration of a filter charging apparatus 50 according to Embodiment 1 of the present invention. In FIG. 1, the filter 1 is the processing target for which the filter charging processing device 50 performs the charging process. The filter 1 can recover the dust collection rate by performing the charging process even if the dust collection rate once decreases due to water washing or the like.

  As shown in the perspective view and the side view of FIG. 2, the filter 1 includes a filter medium 20 formed of a charged nonwoven fabric and a filter frame 18 made of metal, wood, resin, paper, or the like provided around the filter medium 20. It is configured. The filter medium 20 is a three-dimensional filter obtained by folding a charged non-woven fabric into a pleated shape, and has a pleat-shaped valley portion 21 and the upper surface is used as a charged filter medium.

  Further, the filter frame 18 is provided in the filter 1 for the purpose of maintaining the shape of the filter medium 20 and improving the mountability, so that the periphery of the filter medium 20 is fixed and the pleat shape of the filter medium 20 is maintained. belongs to.

  As shown in FIG. 1, the filter electrification processing device 50 includes an electrostatic spray electrode 4 provided at an upper portion in the device and a drift electrode 2 provided at a lower portion in the device. The electrostatic spray electrode 4 is provided such that a plurality of needle nozzle electrodes 4a and a holed electrode 4b having a plurality of holes formed in a flat plate are arranged in a one-to-one correspondence. .

  The drift electrode 2 is provided below the perforated electrode 4 b, and a drift space 13 is formed between the perforated electrode 4 b and the drift electrode 2. Here, the drift electrode 2 is electrically insulated from the apparatus housing 10 by the insulator 9.

  The drift electrode 2 is connected to the first power supply 11, and the needle nozzle electrode 4 a is connected to the second power supply 12. The perforated electrode 4b and the device housing 10 are electrically connected to the ground. Further, the aqueous solution 7 is supplied to the needle nozzle electrode 4a through a pump 8 from a container in which an aqueous solution 7 containing colloidal silica (for example, a concentration of 20% and an average primary particle diameter of about 5 nm) is held.

  The filter 1 is held on a frame-like filter support 5 made of an insulating material and is placed in the drift space 13. The position of the filter 1 in the drift space 13 is set slightly above the center in the drift space 13 by adjusting the height of the filter support 5.

  Next, the operation of the filter charging device 50 will be described with reference to FIG. First, with respect to the drift electrode 2, a positive drift voltage having a voltage value not exceeding (the height of the drift space 13−the height of the filter 1) × (air breakdown voltage: 2.8 kV / mm) is applied. Apply from the first power supply 11. Here, for example, when the height of the drift space 13 is 85 mm and the height of the filter 1 is 45 mm, the drift voltage is 40 kV.

  The voltage value calculated by the above equation is a value that is set so as not to cause an air discharge in the drift space 13 even when the filter 1 or the filter frame 18 associated with the filter 1 exists. The drift voltage value is desirably 80% or less of the above calculated value in order to prevent discharge. Moreover, the filter 1 installed between the drift electrode 2 and the perforated electrode 4b is placed in a high electric field (drift electric field) by applying the drift voltage.

  Subsequently, a negative voltage is applied from the second power source 12 to the needle nozzle electrode 4a. For example, when the gap between the tip of the needle nozzle electrode 4a and the center point of the hole of the perforated electrode 4b is 8 mm, a negative voltage of about −6 kV is applied.

At this time, when the aqueous solution 7 containing colloidal silica is supplied from the pump 8 to the needle nozzle electrode 4a, the droplet is negatively charged at the tip of the needle nozzle electrode 4a, and due to the electrical repulsion between the droplets, the diameter is approximately Electron or ion specific charge (electron: 1.7 × 10 ¹¹ C / kg, ion (hydrogen ion)) having a specific charge of about 3.3 × 10 ³ C / kg, dispersed in the atmosphere as a mist of about 20 nm. Charged fine particles 6 having a specific charge lower than 9.65 × 10 ⁷ C / kg) are generated. The generated charged fine particles 6 pass through the perforated electrode 4 b and are supplied into the drift space 13.

  By the above operation, the negative charged fine particles 6 generated from the electrostatic spray electrode 4 move in a high electric field in the drift space 13, so that the negative charged fine particles 6 are accelerated by the electric field and applied to the filter 1. Irradiated. When the process is continued for several tens of seconds to several tens of minutes in this state, the entire portion including the valley portion 21 of the filter 1 is charged, and the dust collection rate is recovered.

  Next, the role of the charged fine particles 6 generated by electrostatic spraying with the electrostatic spray electrode 4 in the filter charging processing apparatus 50 according to the first embodiment will be described in detail with reference to FIGS. FIG. 3 is a diagram for comparison with the first embodiment, and is a schematic diagram in the case where electrons / ions 32 are supplied to the drift space 13 and the filter 1 is irradiated to the filter 1 placed under a high electric field. It is. FIG. 3 shows a state in the course of recharging. The pleated peak portion of the filter 1 is already charged with a certain amount of negative-polarity electrons and ions.

  Here, the pleated trough portion 21 of the filter 1 is not charged, but when further charged, negative-polarity electrons and ions (charged particles 42 a) are already charged on the filter 1. Due to the influence of the electric field 41 formed by the active electrons and ions (charged particles 42), the orbit 45 a moving away from the filter 1 is received by receiving the Coulomb force 44 away from the filter 1. Therefore, the pleat-shaped valley portion 21 is not charged, and recovery of the collection rate is hindered.

  On the other hand, in FIG. 4 showing the case of the first embodiment, by supplying charged fine particles 33 having a low specific charge of about 1 / 500,000 or less to the specific charge of electrons to the drift space 13, Even if the portion is charged to a negative polarity, the influence of the inertial force on the Coulomb force 44 received by the charged fine particles 6 is remarkably increased as compared with electrons and ions, so that the charged fine particles 6 have a pleated shape. Instead of being repelled by the Coulomb force 44 at the peak, the track 45 b approaching the filter 1 is taken, reaches the pleated trough 21 of the filter 1, and adheres to the filter 1.

  As a result, the charged fine particles 6 attached to the filter 1 are adhered to the filter 1 while the charge is maintained at a secondary particle diameter of about 15 nm as the water is evaporated and the colloidal silica contained in the aqueous solution 7 is aggregated. Therefore, the valley portion 21 having a pleat shape is also charged, and recovery of the collection rate proceeds.

  Next, FIG. 5 shows the result of executing the recharging process using the filter charging apparatus 50 according to Embodiment 1 of the present invention. Here, the filter 1 (mountain height: 45 mm) folded in a pleat shape was washed, and the electret filter after the loss of charge was subjected to a recharging process for 5 minutes to evaluate the surface potential distribution of the pleats.

  In FIG. 5, the charging of the pleat-shaped peak portion is inferior to the charging due to the irradiation of electrons and ions, but the charging of the pleated-shaped valley portion 21 that could not be charged by the irradiation of electrons or ions is also more charged than the new one. It was confirmed that it was possible.

  In addition, when the collection rate of a new filter was evaluated with a filtration rate of air dust having a diameter of 0.3 to 0.5 μm under a wind speed of 1 m / sec, the collection performance was approximately 50%. The latter filter decreased to 10%.

  Here, what was recharged only by electron or ion irradiation recovered only to about 20%, but using the filter electrification apparatus 50 of the first embodiment, the charged fine particles 6 having a low specific charge. Thus, the filter 1 subjected to the recharging process was recovered to 50% equivalent to that of a new product.

  In this way, by generating the charged fine particles 6 having a lower specific charge than electrons and ions and irradiating the filter 1 with a high electric field, the whole of the pleated filter 1 including the pleated trough portion 21 is included. Can be recovered, and the collection rate significantly reduced by the loss of electrification in washing can be recovered to the same level as a new product.

As described above, according to the first embodiment, the filter electrification processing apparatus applies a voltage between electrodes to form a pair of electrodes that form a drift electric field between the electrodes and the drift electric field from electrons and ions. A charged fine particle generation unit that generates and supplies charged fine particles having a small specific charge, and irradiates the charged fine particles drifted by a drift electric field toward a filter to be processed installed between the electrodes, Charge the filter.
Therefore, when charging the filter, the charged particles can reach the deep part of the three-dimensional filter, and the entire filter can be uniformly charged.

The specific charge of the charged fine particles is within the range of 10 ⁻³ C / kg to 10 ⁷ C / kg, and the charged fine particle generation unit is an electrostatic spray electrode composed of a needle nozzle electrode and a perforated electrode The charged fine particles are generated by electrostatic spraying of droplets.
Therefore, in charging the pleated filter, the charged fine particles can reach the pleated valley that is difficult to reach by electrons or ions due to inertia, and the entire filter including the valley can be charged.

In the first embodiment, the example in which the filter 1 is irradiated with the charged fine particles 6 having the specific charge of 3.3 × 10 ³ C / kg is shown. However, the specific charge of the charged fine particles 6 is preferably 10 ^{−. It} is good to use in the range of ³ C / kg-10 ⁷ C / kg. This is because if the specific charge is too large, the charged fine particles 6 cannot reach the pleated valley 21 due to the repulsion caused by charging of the pleat-shaped crest as in the case of electrons and ions, and the specific charge is too small. This is because the charging effect of the filter 1 is reduced.

  Moreover, in the said Embodiment 1, although the example whose density | concentration 20% and average primary particle diameter are about 5 nm was shown as conditions of the aqueous solution 7 containing the colloidal silica to spray, Preferably, primary particle diameter is 1 nm-500 micrometers. It is good to use in the range. This is because, if the particle diameter is too small, the charged fine particles 6 cannot reach the pleated valley 21 due to repulsion due to the charging of the pleated ridges, as in the case of electrons and ions, and the particle diameter is too large. This is because the effect of charging the filter 1 is reduced.

  Moreover, in the said Embodiment 1, although the aqueous solution 7 containing colloidal silica was used as the aqueous solution 7 to spray, it is not limited to this, For example, you may use water and ethanol. As a result, the filter 1 can be charged without adhering foreign matter. However, as described above, it is only necessary to spray droplets having a lower specific charge than electrons and ions, and the liquid type is not particularly limited.

Embodiment 2. FIG.
FIG. 6 is a cross-sectional view showing a configuration of a filter electrification processing device 50A according to Embodiment 2 of the present invention. The second embodiment of the present invention is different from the first embodiment in that electrostatic spraying is performed using the metal foam electrode 4c.

  As shown in FIG. 6, the filter electrification processing device 50 </ b> A includes an electrostatic spray electrode 4 provided at a lower portion in the device and a drift electrode 2 provided at an upper portion in the device. The electrostatic spray electrode 4 includes a foam metal electrode 4c and a perforated electrode 4b. The foam metal electrode 4c is made of a foamable metal having a large number of pores, and has a protruding shape at a part thereof. ing.

  Further, the positional relationship between the hole of the perforated electrode 4b and the protrusion of the metal foam electrode 4c corresponds to one-to-one and is provided so as to be opposed to each other. Here, an insulating container 14 is disposed below the foam metal electrode 4c, and an aqueous solution 7 containing colloidal silica (for example, a concentration of 20% and an average primary particle diameter of about 5 nm) is held in the insulating container 14 and foamed. A part of the metal electrode 4 c is immersed in the aqueous solution 7.

  The drift electrode 2 is provided above the perforated electrode 4 b, and a drift space 13 is formed between the perforated electrode 4 b and the drift electrode 2. Here, the drift electrode 2 is suspended from the device housing 10 by an insulator 9 and is electrically insulated from the device housing 10.

  The drift electrode 2 is connected to the first power supply 11, and the foam metal electrode 4 c is connected to the second power supply 12. The perforated electrode 4b and the device housing 10 are electrically connected to the ground. The filter 1 is held on a frame-like filter support 5 made of an insulating material and is placed in the drift space 13. Note that the description of the same configuration as that of the first embodiment is omitted.

  Next, the operation of the filter charging device 50A will be described with reference to FIG. First, a positive drift voltage is applied from the first power supply 11 to the drift electrode 2 as in the first embodiment. Moreover, the filter 1 installed between the drift electrode 2 and the perforated electrode 4b is placed in a high electric field by applying the drift voltage.

  Subsequently, a negative voltage is applied from the second power supply 12 to the foam metal electrode 4c. For example, when the gap between the tip of the foam metal electrode 4c and the center point of the hole of the perforated electrode 4b is 8 mm, a negative voltage of about −6 kV is applied. Here, the foam metal electrode 4c is immersed in the aqueous solution 7 in the insulating container 14, and the foam metal electrode 4c always contains a certain amount of the aqueous solution 7 due to the suction effect by the pores.

  At this time, the droplet of the aqueous solution 7 containing colloidal silica is negatively charged at the tip of the projecting portion of the foam metal electrode 4c, and due to the electric repulsion between the droplets, the droplet has a diameter and a mist of about 20 nm in the atmosphere. Dispersed and charged fine particles 6 having a specific charge lower than that of electrons and ions are generated. The generated charged fine particles 6 pass through the perforated electrode 4 b and are supplied into the drift space 13.

  By the above operation, the negative charged fine particles 6 generated from the electrostatic spray electrode 4 move in a high electric field in the drift space 13, so that the negative charged fine particles 6 are accelerated by the electric field and applied to the filter 1. Irradiated. When the process is continued for several tens of seconds to several tens of minutes in this state, the entire portion including the valley portion 21 of the filter 1 is charged, and the dust collection rate is recovered.

  Thus, by using the foam metal electrode 4c having a protruding shape in part, it is possible to perform stable water supply without using a supply facility such as a pump, and to stably perform electrostatic spraying. it can.

As described above, according to the second embodiment, the filter electrification apparatus applies a voltage between the electrodes to form a pair of electrodes that form a drift electric field between the electrodes and the drift electric field from electrons and ions. A charged fine particle generation unit that generates and supplies charged fine particles having a small specific charge, and irradiates the charged fine particles drifted by a drift electric field toward a filter to be processed installed between the electrodes, Charge the filter.
Therefore, as in the first embodiment, when the filter is charged, charged particles can reach the deep part of the three-dimensional filter, and the entire filter can be uniformly charged.

The electro fine particle generation unit has an electrostatic spray electrode composed of a foam metal electrode and a perforated electrode, and generates charged fine particles by electrostatic spraying of droplets.
Therefore, the solution can be supplied to the electrostatic spray electrode uniformly and uniformly, and charged fine particles can be generated stably.

Embodiment 3 FIG.
FIG. 7 is a cross-sectional view showing a configuration of a filter charging apparatus 50B according to Embodiment 3 of the present invention. In the third embodiment of the present invention, the fine particle generator 15 is used to generate liquid or powdery fine particles, the fine particles are charged by discharging and charged, and the charged fine particles 6 are generated. 2 and different.

  As shown in FIG. 7, the filter electrification processing device 50 </ b> B includes a fine particle generator 15 provided in the upper part of the device and a discharge electrode 47 provided in the lower part of the fine particle generator 15. The discharge electrode 47 includes a discharge high-voltage electrode 47a and a discharge ground electrode 47b. Here, the discharge electrode 47 employs a wire for the discharge high-voltage electrode 47 a in order to perform corona discharge, and this wire is connected to the discharge power source 16.

  The discharge ground electrode 47b is a plate-like electrode and is electrically connected to the ground. The discharge high-voltage electrodes 47a and the discharge ground electrodes 47b are alternately arranged in parallel and alternately, and as a whole, the discharge portions are arranged so as to cover an area larger than the upper surface of the filter 1.

  A metal grid electrode 48 is provided below the discharge electrode 47. Further, the drift electrode 2 is provided below the grid electrode 48, and the drift space 13 is formed between the grid electrode 48 and the drift electrode 2. Note that the description of the same configuration as that of the first embodiment is omitted.

  Next, the operation of the filter charging apparatus 50B will be described with reference to FIG. First, a positive drift voltage is applied from the first power supply 11 to the drift electrode 2 as in the first embodiment. Further, the filter 1 placed between the drift electrode 2 and the grid electrode 48 is placed in a high electric field by applying the drift voltage.

  Subsequently, by applying a high voltage of about 7 kV from the discharge power supply 16 to the discharge high voltage electrode 47a, a corona discharge is formed. Here, powder particles such as colloidal silica powder are generated from the particle generator 15 and supplied toward the discharge electrode 47.

  At this time, when the fine particles from the fine particle generator 15 pass through the discharge part, the charged fine particles 6 are generated by being charged. The generated powdery charged fine particles 6 are supplied into the drift space 13 after passing through the grid electrode 48.

  By the above operation, the powdery fine particles generated by the fine particle generator 15 are charged by discharge to generate charged fine particles 6, and the charged fine particles 6 are supplied to the drift space 13. As described above, the negative charged fine particles 6 move in a high electric field of the drift space 13, whereby the negative charged fine particles 6 are accelerated to the electric field and irradiated to the filter 1. When the process is continued for several tens of seconds to several tens of minutes in this state, the entire portion including the valley portion 21 of the filter 1 is charged, and the dust collection rate is recovered.

  At this time, electrons and ions generated by corona discharge at the discharge high-voltage electrode 47a are also supplied to the drift space 13 and irradiated to the filter 1, so that the charging process using only the charged fine particles 6 as shown in FIG. Compared with, the peak portion of the filter 1 is more highly charged.

  In this way, charging by electron or ion irradiation and charging by the charged fine particles 6 can be performed simultaneously, and a higher charging effect can be obtained as compared with the case where the charging process is performed only by the charged fine particles 6. it can.

  In addition, by separating the generation of fine particles from the charging of the fine particles, it is not limited to charging with fine particles of droplets, and even fine particles that are difficult to be charged by electrostatic spraying, such as fine particles of powder, are relatively simple. With such a configuration, the filter 1 can be efficiently charged and irradiated as the charged fine particles 6.

As described above, according to the third embodiment, the filter electrification apparatus applies a voltage between the electrodes to form a pair of electrodes that form a drift electric field between the electrodes and the drift electric field from electrons and ions. A charged fine particle generation unit that generates and supplies charged fine particles having a small specific charge, and irradiates the charged fine particles drifted by a drift electric field toward a filter to be processed installed between the electrodes, Charge the filter.
Therefore, as in the first embodiment, when the filter is charged, charged particles can reach the deep part of the three-dimensional filter, and the entire filter can be uniformly charged.

The charged particle generation unit includes a particle generator and a discharge electrode, and generates charged particles by charging the particles generated by the particle generator by discharging at the discharge electrode.
Therefore, charging with electrons and ions and charging with charged fine particles can be performed simultaneously, and a higher charging effect can be obtained as compared with the case where the charging process is performed with only charged fine particles.

  In the third embodiment, an example in which colloidal silica powder is used as the powder generated from the fine particle generator 15 is shown, but the present invention is not limited to this. For example, a ferroelectric material such as barium titanate is used. Powder may be used. Ferroelectric material powders are charged with a high amount of charge, so a higher charge can be obtained compared to the case where the filter is charged with colloidal silica powder and the charge is maintained for a longer period of time. can do.

  In the third embodiment, the fine particle generator 15 includes, for example, a configuration including a sieve that continuously discharges a certain amount of particles per unit time, and a configuration including a fan for transporting the particles to the discharge electrode 47. This can be realized by supplying an arbitrary powder to the fine particle generator 15.

  In the third embodiment, as shown in the first and second embodiments, the charging process can be performed with fine particles of droplets. Specifically, for example, the fine particle generator 15 includes a nebulizer and a fan, and water, ethanol, colloidal silica aqueous solution is used as a mist from the nebulizer to generate droplet fine particles. This can be realized by transporting the droplet fine particles to the discharge electrode 47 and charging them.

  DESCRIPTION OF SYMBOLS 1 Filter, 2 Drift electrode, 4 Electrostatic spray electrode, 4a Needle nozzle electrode, 4b Hole electrode, 4c Foam metal electrode, 5 Filter support material, 6 Charged fine particle, 7 Aqueous solution, 8 Pump, 9 Insulator, 10 Device housing Body, 11 first power source, 12 second power source, 13 drift space, 14 insulating container, 15 particulate generator, 16 discharge power source, 18 filter frame, 20 filter media, 21 filter shaped valley, 32 electrons and ions, 33 Charged fine particle, 41 Electric field, 42 Charged particle, 42a Charged particle, 44 Coulomb force, 45a, 45b Orbit, 47 Discharge electrode, 47a Discharge high voltage electrode, 47b Discharge ground electrode, 48 Grid electrode, 50, 50A, 50B Filter electrification processing device .

Claims (7)

A pair of electrodes that form a drift electric field between the perforated electrode and the drift electrode by applying a voltage to the drift electrode, comprising a perforated electrode and a plate-shaped drift electrode;
A charged fine particle generation unit that generates and supplies charged fine particles having a smaller specific charge than electrons and ions to the drift electric field, and
A filter charging apparatus that charges the filter by irradiating charged fine particles drifted by the drift electric field toward a processing target filter disposed between the electrodes. The filter charge processing apparatus according to claim 1, wherein a specific charge of the charged fine particles is in a range of 10 ⁻³ C / kg to 10 ⁷ C / kg . The charged particle generation unit includes an electrostatic spray electrode configured by a needle nozzle electrode and a perforated electrode, and generates the charged particle by electrostatic spraying of a droplet. Filter electrification device. 3. The charged fine particle generation unit includes an electrostatic spray electrode including a foam metal electrode and a perforated electrode, and generates the charged fine particle by electrostatic spraying of droplets. Filter electrification device. The charged particle generation unit includes a particle generator and a discharge electrode, and generates the charged particle by charging the particle generated by the particle generator by discharging at the discharge electrode. The filter electrification processing apparatus according to claim 2. An electric field forming step comprising a holed electrode and a plate-like drift electrode, and forming a drift electric field between the holed electrode and the drift electrode by applying a voltage to the drift electrode;
A generation step for generating charged fine particles having a specific charge smaller than that of electrons and ions;
Supplying the charged fine particles to the drift electric field;
A charging step for charging the filter by irradiating the charged fine particles drifted by the drift electric field toward the processing target filter installed between the electrodes,
A method for charging a filter. The filter charging method according to claim 6, wherein the charged fine particles are generated from a ferroelectric material.

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