JP2606102Y2 - Static eliminator - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a static eliminator for removing dust or the like adhering to a charged body such as plastics and ceramics.

[0002]

2. Description of the Related Art A charged body such as plastics or ceramics is charged with static electricity by friction and attracts dust floating in the air by electrostatic attraction. By the way, when a product is assembled by applying a paint to a charged body to which dust has adhered, problems such as poor appearance of the product arise. In order to solve such a problem, there is known a static eliminator and a dust remover in which a nozzle of an air gun is provided with a discharge electrode for generating positive and negative air ions by corona discharge. According to the static eliminator, by blowing positive and negative air ions together with the compressed air onto the charged body, the air ions neutralize the static electricity of the charged body and the dust adhering to the charged body, thereby reducing the adhesion of the dust. The weakened and weakened dust is blown off with compressed air and removed.

However, in such a static eliminator and dust remover, the reach of compressed air ejected from a nozzle is short,
Therefore, there is a disadvantage that the air flow containing the air ions is attenuated on the way and dust or the like attached to the charged body cannot be effectively removed.

[0004] Here, as a result of intensive studies by the present inventors,
It has been found that the reason why the air flow attenuates in the middle is that the compressed air is ejected from the nozzle in a turbulent state. More specifically, a dimensionless number that distinguishes a laminar flow and a turbulent flow in a gas flow is a Reynolds number Re = u × d / ν (hereinafter referred to as Expression (1)) represented by a ratio of an inertial force to a viscous force. U: flow rate (mm / s), d: nozzle diameter (m
m), ν: kinematic viscosity coefficient (mm ² / s)), laminar flow when the Re number is 2300 to 3000 or less, and turbulent flow when the Re number is more than 2300.
In the conventional air gun, the nozzle diameter is usually 2 m.
m, and air at a pressure of 2-3 kg / cm ² is blown at an air volume of 20 liter / min. The flow velocity u in this case
Is the air flow rate of 20 liters / min.
14 mm ² ≒ 106 × 10 ³ mm / s. Therefore,
Substituting u and d in the above-mentioned air gun into the above equation (1) with the kinematic viscosity coefficient ν of the air being 10.5 mm ² / s,
The Re number was 106 × 10 ³ × 2 / 10.5 ≒ 20190, which resulted in complete turbulence, which caused the air flow to attenuate on the way.

[0005]

SUMMARY OF THE INVENTION The present invention has been made based on such knowledge, and has been made so that an air flow containing air ions blown out from a nozzle can fly far without being attenuated on the way. It is an object of the present invention to provide a static elimination device capable of effectively removing dust and the like attached to a body.

[0006]

According to the present invention, in order to achieve the above object, an air supply port for supplying compressed air is formed at a base end portion, and a nozzle for jetting compressed air is provided at a distal end portion. Device body, air supply means for supplying compressed air to the air supply port, a discharge electrode that is provided at the tip of the device body and generates a corona discharge when a voltage is applied, and a discharge electrode Voltage supply means for applying a voltage, wherein positive and negative air ions generated by the corona discharge of the discharge electrode are sprayed on the charged body together with compressed air ejected from the nozzle, whereby dust adhering to the charged body is discharged. in neutralization filtration apparatus for removing such, the nozzle, the flow of the compressed air injected is formed in a cylindrical shape to have a nozzle diameter such that a laminar flow, and compressed air
Are provided and arranged in parallel with each other so as to form a uniform band-like flow .

The compressed air inflow portion of the nozzle has a bell mouth shape.

The interval between the nozzles is set to be 2 to 3 times the diameter of the nozzle.
And the length of the nozzle is at least 1.6 times the diameter of the nozzle.

[0009]

According to the present invention, a laminar air flow is blown in parallel from a plurality of nozzles, so that an air flow containing positive and negative air ions can be blown far without being attenuated on the way. . In this case, in order to obtain a laminar air flow, it is necessary to reduce the diameter of the nozzle. Therefore, by providing a plurality of nozzles, an air volume equivalent to that of a conventional air gun is obtained. The air volume is set by adjusting the number of nozzles. Further, by arranging the respective nozzles in parallel and blowing out the laminar air flows in parallel, the respective air flows can be merged on the way to obtain a belt-like flow.

Further, if the shape of the compressed air inflow portion of the nozzle is a bell mouth, the pressure loss of the compressed air flowing into the inflow portion can be reduced, so that the air flow can be blown farther. .

Further, when the interval between the nozzles is set to two to three times the diameter of the nozzle and the length of the nozzle is set to 1.6 times or more the diameter of the nozzle, the laminar air flow is generated from the nozzle. It is possible to obtain a uniform belt-like flow by merging at about 50 mm, and to fly the air flow farther.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an overall schematic view of a static eliminator and dust remover according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of a tip end of the apparatus main body, and FIG. 3 is a view for explaining a flow of compressed air blown out from each nozzle. FIG.

In FIG. 1, reference numeral 1 denotes a static eliminator and a dust remover, and the static eliminator and dust remover 1 includes an apparatus main body 2. The device main body 2 is made of, for example, an insulating material such as engineering plastic, and is formed widely from the base end portion to the tip end portion to have a substantially fan shape. An air supply port 3 to which compressed air is supplied is formed at a base end of the apparatus main body 2, and the air supply port 3 is connected to an air compressor 5 via an air hose 4. A plurality of nozzles 6 are provided at the front end of the apparatus main body 2 at equal intervals in the width direction and in parallel with each other. Further, as shown in FIG. 2, the shape of the compressed air inflow portion 6a of the nozzle 6 is a bell mouth shape in order to reduce pressure loss.

Here, the diameter d of the nozzle 6 is set to about 1 mm so that a laminar air flow is blown out from the nozzle 6 in the above-mentioned formula (1), and the number of the nozzles 6 is the same as that of the conventional air gun. 10 to 20 airflows (20 liters / min) are obtained. In addition, each nozzle 6
The pitch of the nozzle 6 is set to 2d to 3d so that the blown compressed air joins at about 50 mm from the tip of the nozzle 6 to form a uniform two-dimensional free jet W (band-like flow: see FIG. 3). The length is about 1.6d to 2d in order to obtain a stable laminar flow state.

Each nozzle 6 is provided with a plurality of alternate needle electrodes 7. Each of the needle electrodes 7 extends rearward in the apparatus main body 2, and thereafter is bundled into a single piece to form a wiring 8, and is drawn out of the apparatus main body 2 as a high-voltage cable 9.
The high voltage cable 9 is connected to an AC high voltage power supply 10. A ground electrode 11 is provided on the outer periphery of the distal end portion of the apparatus main body 2 along the circumferential direction, and the ground electrode 11 is grounded via a lead wire 12.

Next, the operation will be described. Air compressor 5
Is operated to supply compressed air to the air supply port 3 of the apparatus main body 2, the compressed air is blown out of each nozzle 6 in parallel through the inside of the apparatus main body 2, and merges on the way to form a uniform belt-like flow. . At this time, as described above, compressed air is blown out from each nozzle 6 in a laminar flow state, and since the shape of the inflow portion 6a of the nozzle 6 is formed as a bell mouth to reduce pressure loss, the air is blown out from each nozzle 6. The air flow is blown far without being attenuated on the way.

At the same time, an AC high voltage is applied to the needle electrode 7 from the AC high voltage power supply 10 via the high voltage cable 9, and a high electric field is formed between the needle electrode 7 and the ground electrode 11. As a result, the electric field is concentrated at the tip of each needle electrode 7, an alternating current corona discharge is generated, and positive and negative air ions are generated alternately. Then, the generated positive and negative air ions ride on a laminar airflow blown out in parallel from each nozzle 6 and are blown away with the airflow. For this reason, compared with the case of using the conventional air gun, the air flow containing positive and negative air ions can reach far without being attenuated on the way,
Accordingly, by blowing the air flow onto the charged body (not shown) to which dust is attached, the static electricity between the charged body and dust is neutralized by positive and negative air ions, and the compressed air is applied to the surface of the charged body by compressed air. The attached dust is blown off and removed effectively.

Next, in order to clarify the difference between the static eliminator and dust remover 1 of the present embodiment and a conventional air gun, a detailed description will be given with reference to FIGS. In FIG. 4, reference numeral 13 is 15
0 mm × 150 mm charging plate 13 a (capacitance 2
0 pF ± 2 pF), and the nozzles 6 of the apparatus main body 2 are opposed to each other at a position separated by a predetermined distance L (mm) from the charging plate 13a. Here, the nozzle diameter is 1 mm, and the number of nozzles is 16
The pitch between the nozzles is 2.6 mm, the nozzle length is 1.8 mm, and the AC voltage applied to the needle electrode 7 is ± 7.5 kV.
And

Then, a voltage of ± 5 kV is applied to the charging plate 13a, and the distance L is gradually increased so that compressed air (2 kg / cm ² ) is discharged from each nozzle 6 to the charging plate 13a.
And the time t (sec) required for the voltage on the charging plate 13a to reach ± 100 V for each of the positive and negative sides.
Was measured. The conventional air gun (nozzle diameter 2)
mm and a nozzle length of 3.6 mm) were measured under the same conditions. FIG. 5 shows the measurement results.

FIG. 5 shows the distance L (horizontal axis) and the charging plate 1.
5 is a graph showing a relationship between time t (vertical axis) required for the voltage at 3a to become ± 100 V for each of positive and negative. As is apparent from this figure, in the conventional air gun, when the distance L exceeds 500 mm, the time t gradually increases as compared with the device 1 of the present embodiment, and becomes nearly double at the time of 1200 mm. It can be seen that when the distance L is 1200 mm, the charge elimination of the charging plate 13a is not performed.
This means that the air flow containing the air ions blown out from the air gun begins to attenuate at a distance L of around 500 mm.
It means that it can only reach up to 200mm. On the other hand, in the static elimination device 1 of the present embodiment, the distance L is 2
It can be seen that even when the distance reaches 000 mm, the relationship between the distance L and the time t is linearly maintained, and the charge elimination of the charging plate 13a is successfully performed. This means that the air flow including the air ions blown out from each nozzle 6 reaches far without being attenuated on the way.

The present invention is not limited to the above embodiment, but can be changed as appropriate without departing from the gist of the present invention. For example, in the above embodiment, the ground electrode 11 is provided along the circumferential direction on the outer periphery of the distal end portion of the apparatus main body 2. Instead, as shown in FIG. The lower end of the device 2 may be provided with its tip protruding from the tip of the apparatus body 2.

In the above embodiment, the shape of the apparatus main body 2 is substantially fan-shaped, which is formed wide from the base end to the front end. Instead, as shown in FIG. , A cylindrical device main body 15,
Nozzles 6 may be provided on the end face of the nozzle 5 at equal intervals around the entire circumference.

Further, in the above embodiment, an AC corona discharge in which an AC voltage is applied to the needle electrode 7 to generate positive and negative air ions alternately is employed. As described above, a pair of needle electrodes 16 and 17 are provided in the nozzle 6 at a predetermined interval, and each of the needle electrodes 16 and 17 is connected via a high-voltage cable 18 or 19 to a positive DC high-voltage power supply (not shown). To the needle electrodes 16 and 17 to apply positive and negative DC voltages to the needle electrodes 16 and 17, respectively.
DC corona discharge, which generates a high electric field between the needle electrode 6 and the needle electrode 17 to generate positive air ions at the needle electrode 16 and negative air ions at the needle electrode 17, may be employed.

In the above embodiment, the needle electrode 7 is provided inside the nozzle 6. However, the present invention is not limited to this. Needless to say, the needle electrode 7 can be provided near the nozzle 6. is there.

[0025]

As is apparent from the above description, according to the present invention, a band-like air flow containing positive and negative air ions from a plurality of nozzles can be made to fly far without being attenuated on the way. In addition, dust and the like attached to the charged body can be effectively removed.

When the pressure loss of the compressed air flowing into the inflow portion is reduced by setting the shape of the inflow portion of the compressed air of the nozzle to a bell mouth, the air flow can be made to fly farther, so that it adheres to the charged body. Dust and the like can be more effectively removed.

Further, the interval between the nozzles is set to be two to three times the diameter of the nozzle, and the length of the nozzle is set to be 1.6 times or more the diameter of the nozzle, so that the laminar air flow is five times from the nozzle.
The air stream can be made to fly farther by merging at about 0 mm to form a band-like uniform flow.

[Brief description of the drawings]

FIG. 1 is an overall schematic view of a static eliminator and dust remover according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a distal end portion of the apparatus main body.

FIG. 3 is an explanatory diagram for explaining a flow of compressed air blown out from each nozzle.

FIG. 4 is an explanatory schematic diagram for explaining an experimental example of the static elimination and dust removal apparatus of the present embodiment.

FIG. 5 is a graph showing a relationship between a distance L (horizontal axis) and a time t (vertical axis) required for the voltage at the charging plate to become ± 100 V for each of positive and negative.

FIG. 6 is an overall schematic view of a static eliminator and dust remover according to another embodiment of the present invention.

FIG. 7 is an overall schematic view of a static eliminator and dust remover according to another embodiment of the present invention.

FIG. 8 is an overall schematic view of a static eliminator and dust remover according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Static electricity removal dust removal apparatus, 2 ... Device main body, 3 ... Air supply port, 5
... air compressor, 6 ... nozzle, 6a ... inflow section, 7 ...
Needle electrode, 10: AC high-voltage power supply, 11: Ground electrode

Continued on the front page (72) Inventor Hidemi Nagata 1-10-8 Motomiya, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Shisiido Electrostatic Co., Ltd. Yokohama Plant (72) Inventor Kenkichi Izumi 1-10-8 Motomiya, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture (56) References JP-A-3-53498 (JP, A) JP-A-6-203993 (JP, A) JP-A-62-200733 (JP, A) JP-A-55- 162379 (JP, A) Fully open sho 57-189113 (JP, U) Fully open sho 60-193285 (JP, U) Fully open sho 53-9974 (JP, U) Fully open sho 60-4337 (JP, U) Japanese Utility Model Application No. 2-121149 (JP, U) Japanese Utility Model Application No. Sho 52-14773 (JP, U) Japanese Patent Publication No. 43-14520 (JP, B1) Japanese Utility Model Publication No. Sho 42-17512 (JP, Y1) Japanese Patent Publication No. 2-503349 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B08B 7/00

Claims (3)

(57) [Scope of request for utility model registration] 1. An apparatus body having an air supply port formed at a base end thereof for supplying compressed air and a nozzle provided at a distal end thereof for jetting compressed air, and supplying compressed air to the air supply opening. An air supply unit, a discharge electrode provided at a tip end of the apparatus main body to generate a corona discharge when a voltage is applied, and a voltage supply unit for applying a voltage to the discharge electrode; A positive / negative air ion generated by the discharge is blown to the charged body together with the compressed air blown out from the nozzle to thereby remove dust and the like attached to the charged body. flow of compressed air is formed in a cylindrical shape to have a nozzle diameter such that a laminar flow, and pressure
A static eliminator and dust remover , wherein a plurality of compressed air flows are arranged parallel to each other so as to be a band-like uniform flow . 2. The static eliminator and dust remover according to claim 1, wherein the shape of the compressed air inflow portion of the nozzle is a bell mouth. 3. An interval between each nozzle is set to a value of 2 to 3 of the diameter of the nozzle.
The static eliminator according to claim 1 or 2, wherein the length of the nozzle is 1.6 times or more the diameter of the nozzle.