JP2997835B2 - Ionization static eliminator with gas ejection mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ionization static eliminator having a gas ejection mechanism.

This static eliminator is made of, for example, plastic,
Used in the production or processing of paper, fiber, glass, etc., to remove static electricity from charged objects (objects of static elimination), such as products, to prevent obstacles due to static electricity such as adhesion of dust and generation of sparks. You.

[0003]

2. Description of the Related Art As this type of static eliminator, for example, as disclosed in Japanese Utility Model Publication No. 59-38382, a discharge electrode, a ground electrode and a gas ejection mechanism are provided, and a corona between the discharge electrode and the ground electrode is provided. 2. Description of the Related Art There is known an apparatus in which ions generated by discharge are sprayed on a charged object by a gas ejected from a gas ejection mechanism to remove the charge of the charged object.

Generally, a high voltage is applied to a discharge electrode of a static eliminator, and a ground electrode is arranged around the discharge electrode. It is necessary to keep a certain gap between the discharge electrode and the ground electrode due to the dielectric strength. If the gap between the discharge electrode and the ground electrode is too small, the originally performed corona discharge shifts to a spark discharge, causing extreme wear of the electrode, generation of discharge noise, etc., and the original charge elimination cannot be performed. If the gap is not sufficient, creeping discharge occurs due to the aging of the insulating resin, and the product life of the static eliminator is extremely shortened. For this reason, there are certain restrictions on the shapes and dimensions of the static elimination electrodes (discharge electrodes and ground electrodes) themselves.

[0005] The ions generated by corona discharge are very unstable, and easily return to the original stable state, that is, the state of neutral molecules that have not been ionized. Also, the time required for static elimination is determined by how many ionized gases reach the electrostatically charged material. For this reason, there is a limit to the position where the static eliminator is installed, and accurate static elimination cannot be performed unless the static eliminator can be installed at an appropriate position on a processing or production line.

As is clear from the above description, it is necessary to make a large number of ions reach a charged material as quickly as possible in order to efficiently remove static electricity. The gas ejection mechanism is provided for that purpose, and ejects a gas such as air from the vicinity of the charge removing electrode, puts ions for charge removal on this gas flow, and reaches a distant charged material. Thus, the amount and speed of arrival of ions to the charged material are increased. In a conventional static eliminator equipped with a gas ejection mechanism, the shape of the casing is devised so that gas passes through the gap between the discharge electrode and the ground electrode, or a gas ejection mechanism is separately provided to provide a vicinity of the static eliminator. Gas is made to pass through.

[0007]

In the conventional static eliminator provided with the gas ejection mechanism, as described above, the gas is allowed to pass through the gap between the discharge electrode and the ground electrode, or the gas ejection mechanism is provided separately. Since the gas passes through the vicinity of the static eliminator, it is difficult to reduce the size of the static eliminator. In particular, it is difficult to reduce the size of a static eliminator provided with a plurality of discharge electrodes, which limits the installation position of the static eliminator in a process requiring static elimination in each industry.

Further, since a high voltage is applied to the discharge electrode of the static eliminator, the surrounding dust is attracted and adheres to and accumulates on the discharge electrode, and the dust weakens the electric field at the tip of the discharge electrode. The performance of the static eliminator deteriorates. In order to recover from this performance deterioration, it is essential to periodically clean the discharge electrode as a regular maintenance of the static eliminator. On the other hand, there is a demand for a static eliminator that does not require maintenance because of the human cost of maintenance work and the workability of cleaning depending on the installation position.

An object of the present invention is to provide a device in which a static eliminator equipped with a gas ejection mechanism is compactly integrated, to facilitate installation of the static eliminator in an accurate position, and to improve the productivity and economy of various industries. And so on.

Another object of the present invention is to enhance the static elimination effect,
Et al, the adhesion of dust to the discharge electrodes is reduced, to minimize degradation due to aging of static elimination is greatly extend that the maintenance period of static eliminator.

[0011]

A static eliminator according to the present invention includes a discharge electrode, a ground electrode, and a gas ejection mechanism, and ions generated by corona discharge between the discharge electrode and the ground electrode are ejected from the gas ejection mechanism. In the ionization static eliminator, which discharges the object to be neutralized by spraying the object with the gas, the discharge electrode is formed into a hollow shape with an electric conductor, and the gas discharge port is formed inside the discharge electrode at the tip. Contact with the gas passage of the gas ejection mechanism is formed with a
In addition, a sharp portion is formed at the tip of the discharge electrode .

As the gas ejected from the gas ejection mechanism, for example, dry air, nitrogen or the like is used.

For example, a sharp portion is provided at the tip of the discharge electrode.
Are formed at two places.

For example, the outer surface of the discharge electrode is covered with an insulating coating layer made of an electric insulator .

For example, the insulating coating layer is projected in the gas ejection direction within a range of 2 mm or less from the tip of the discharge electrode.

For example, an electric good conductor is formed outside the discharge electrode.
Casing is arranged, and this casing
The poles are configured.

For example, a cable fixing mechanism for fixing a high-voltage cable for supplying a high voltage from a high-voltage power supply to a casing constituting a ground electrode, a high-pressure joint for electrically connecting the high-voltage cable and the discharge electrode, and a gas A tube fixing mechanism for fixing the supply tube is provided integrally .

[0018]

Since the discharge electrode is formed in a hollow shape, a gas passage is formed inside the discharge electrode, and a gas ejection port is formed at the tip of the discharge electrode, there is no need to separately provide a gas ejection section. Is simplified, and downsizing is possible.

A sharp portion is formed at the tip of the discharge electrode.
Therefore, a sufficient static elimination effect can be obtained.

Two sharp portions at the tip of the discharge electrode
When formed, the static elimination effect can be enhanced.

Further, since the jetted gas always passes through the inside of the discharge electrode, it is possible to prevent dust from adhering to the inner surface of the discharge electrode. In addition, if the outer surface of the discharge electrode is covered with an insulating coating made of an electrical insulator, the insulation between the discharge electrode and the ground electrode can be improved, and dust on the outer surface of the discharge electrode can be improved. Adhesion can be prevented. Therefore, it is possible to maintain good static elimination performance over a long period of time, simplify maintenance of the discharge electrode, and greatly extend the maintenance period .

The insulating coating layer is 2 mm from the tip of the discharge electrode.
In the following range, the electrode and the worker can be protected when projected in the gas ejection direction.

A cable fixing mechanism for fixing a high voltage cable for supplying a high voltage from a high voltage power supply to a casing constituting a ground electrode, a high voltage joint for electrically connecting the high voltage cable and the discharge electrode, and a gas supply When the tube fixing mechanism for fixing the tube is integrally provided, the static eliminator can be compactly integrated .

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a configuration of a main part of the static eliminator, and FIG. 2 shows a part of the apparatus further enlarged. In the following description, up, down, left, and right refer to FIG.

As shown in FIG. 1, the static eliminator includes one casing (2) which also serves as two discharge electrodes (1) and a ground electrode.
It has.

The casing (2) is made of, for example, a metal pipe, which is a good electrical conductor, and is horizontally arranged so as to extend in the left-right direction. In this embodiment, the casing
A round pipe made of stainless steel was used for (2). casing
Inside the left end of (2), a columnar cable support material (support block) (3) made of an insulator is fitted and fixed. Inside the right end of the casing (2), a cylindrical support member (support block) (4) made of insulating material is fitted and fixed. In this embodiment, the support block
(3) A highly insulating fluororesin was used for (4). Each support block
In (3) and (4), holes (5) and (6) penetrating the center in the axial direction are formed. The holes (5) and (6) on the end faces of the support blocks (3) and (4) facing each other have round holes (5a) and (6a) for electrode support material insertion of the same diameter, and the opposite end faces. Holes (5) and (6) are round holes
(5a) (6a) has a thread part (5b) (6b) with a larger diameter than that of the round hole (5a) (6a) and the thread part (5b) (6b). Department
(5a) It becomes smaller than that of (6a). The left and right ends of the electrode support material (support pipe) (7) made of a pipe-shaped electric conductor arranged horizontally so as to extend in the left and right direction are round holes (5a) in the left and right support blocks (3) and (4). ) (6a) and fixed. In this example, an electrolytically polished stainless steel pipe having an outer diameter of about 6.4 mm and an inner diameter of about 4.4 mm was used as the support pipe (7). The discharge electrode (1) is fixed vertically upward at a predetermined pitch above the support pipe (7) between the left and right support blocks (3) and (4). A circular hole (8) having a vertical axis passing through the center of the discharge electrode (1) is formed at two places in the upper part of the casing (2).
The lower end of the discharge electrode (1) penetrates the support pipe (7) and reaches the inside thereof. The upper end of the discharge electrode (1) extends in the center of the corresponding hole (8) to a portion radially inward from the inner surface of the casing (2) when there is no hole (8), and Tip (upper end) of electrode (1) and casing
A predetermined gap is formed between the peripheral edge of the corresponding hole (8) of (2). The outer surface of the discharge electrode (1) projecting above the support pipe (7) is covered with an insulating coating layer (9) made of an electric insulator. The discharge electrode (1) is formed in a hollow shape by, for example, a metal that is a good electrical conductor. In this example,
Electrolytically polished stainless steel pipe having an outer diameter of about 1.1 mm and an inner diameter of about 0.7 mm is used for the discharge electrode (1), and the insulating coating layer (9) is made of highly insulating fluorine having an outer diameter of about 2 mm and an inner diameter of about 1 mm. It was formed by press-fitting a discharge electrode (1) inside a resin tube. The insulating coating layer (9) protrudes upward within a range of 2 mm or less from the tip (upper end) of the discharge electrode (1). In this embodiment, it protrudes by about 0.5 mm. Further, in this embodiment, about 1.2 mm is attached to the peripheral wall of the support pipe (7).
A through-hole (10) having a diameter of 1 mm was formed, and the discharge electrode (1) was inserted into the hole (10), and was fixed by welding so that no gap was formed.
Although not shown, the casing (2) is grounded with a ground resistance of 100Ω or less via a metal fitting and a ground wire.

Screw part (5b) of cable support block (3)
A tube connector (11) is screwed and fixed, and a portion near the tip (right end) of the high-voltage cable (12) is inserted into the center of the connector (11). Cable (12)
a) and a silicone rubber covering (12b) covering the same. Cable protruding to the right from connector (11)
The right end of (12) is inserted into the inside of the left end of the support pipe (7) through the hole (5) of the support block (3), and two diametrically pierced through the support pipe (7). The metal high-pressure joint pin (13) fixes the cable (12) to the support pipe (7), and secures electrical continuity between the cable core wire (12a) and the support pipe (7). The left end of the pipe (7) is sealed by the cable (12) and
(12a) and the discharge electrode (1) are electrically connected.
The cable (12) is covered with a silicone rubber protective tube (14) to prevent damage.
The tip (right end) of 4) is inserted and fixed inside the left end of the connector (11). Although not shown, the other end of the cable (12) is connected to an AC high-voltage power supply.
The cable support block (3) and the connector (11) constitute a cable fixing mechanism for fixing the cable (12) to the casing (2). Also, joint pin (13)
Thus, a high-pressure joint for electrically connecting the cable (12) and the discharge electrode (1) is formed.

Screw part (6b) of tube support block (4)
An air joint (15) is screwed in and fixed, and a distal end (left end) of an air tube (16) for supplying gas is inserted into a right end of the joint (15) and fixed. Although not shown, the other end of the tube (16) is connected to a dry air supply source. The inside of each discharge electrode (1) is a gas passage
(1a), the tip (upper end) is a gas outlet (1b). The support block (4) and the joint (15) constitute a tube fixing mechanism for fixing the tube (16). The tube (16), the joint (15), the support block (4), the support pipe (7), and the gas passage (1a) and the gas outlet (1b) of the discharge electrode (1) make a part of the gas ejection mechanism. It is configured. As shown in detail in FIG.
Is cut-edge portion is obliquely pole (1), the sharp portion (1c) is 1箇
Is formed. As shown in FIG. 4, the discharge electrode (1)
Two sharp portions (1d) may be formed at the tip. In addition,
3 and 4, the same parts as those in FIG.
No. is attached.

In the above static eliminator, the high voltage output from the AC high-voltage power supply passes through the core wire (12a) of the cable (12), passes through the joint pin (13) and the support pipe (7), and discharges the discharge electrode (1). Is applied to For this reason, a large potential difference occurs between the discharge electrode (1) and the casing (2), and the discharge electrode
A high electric field is applied via the insulating coating layer (9) of (1), and the discharge electrode
Corona discharge occurs at the tip of (1). On the other hand, dry air supplied from a dry air supply source via a tube (16) is supplied to the inside of the joint (15), the hole (6) of the support block (4), the inside of the support pipe (7), and the discharge electrode (1). ) Through the gas passage (1a), and is blown upward from the gas outlet (1b). At that time, due to the corona discharge generated at the tip of the discharge electrode (1), the dry air is electrically excited and ionized, and is converted into positive and negative ions. Then, these ions are blown against a charged object (not shown) by dry air blown out from the ejection port (1b), and the charged object is discharged.

Dry air is supplied to the above static eliminator by a tube (1).
6), and an AC high voltage whose waveform was controlled was applied via a cable (12). Further, the insulated and held metal plate was used as a pseudo-charged plate, and the same was charged for 500
It was charged to 0V. Then, the ionized air blown out of the static eliminator was sprayed on the pseudo-charging plate, and the state of the static elimination of the charging plate was observed using an electrostatic measurement device. As a result, it was confirmed that the use of the above-described static eliminator ensures that the pseudo-charging plate was neutralized.

Further, the use of medium-empty-shaped discharge electrode (1), I'm <br/> to form sharp edges on the leading end portion of the electrode (1), it is to apply a high electric field It was confirmed that corona discharge which did not lead to spark discharge was performed, and that positive and negative ions required for static elimination could be sufficiently generated. That is , as shown in FIG. 3, the tip of the discharge electrode (1) is cut obliquely to form one sharp portion (1c), or as shown in FIG. by sharp portion at the front end portions of the electrodes (1) to (1d) to or formed in two places, it is possible to enhance the static elimination effect.

The installation distance between the pseudo charging plate and the gas outlet (1b) at the tip of the discharge electrode (1) of the static eliminator is 50 m.
m or less, the time required to remove the charge from 5000 V to 500 V or less was 1 second or less, regardless of whether the charging polarity of the pseudo charging plate was positive or negative. In addition, the time required for static elimination increases as the installation distance increases,
As the supply air pressure increased, the time required for static elimination was shortened. Further, as shown in FIG. 3 or FIG.
By processing the tip of (1) into an appropriate shape, the static elimination time could be reduced slightly.

When a sine wave AC high voltage without waveform control is applied, even if the charged object is processed by the above-described static eliminator, due to residual charging or reverse charging, complete static elimination up to around 0 V can be achieved. Not done.

When the above static eliminator is used in the actual static elimination step, the function of the AC high voltage power supply and the voltage applied to the electrodes, the installation distance to the object, the pressure of the supplied gas, and the like are sufficiently determined. Need to consider.

[0036]

According to the static eliminator of the present invention, as described above, there is no need to separately provide a gas ejection section, and the apparatus can be simplified and downsized. Therefore, the space can be reduced, the problem of installation on an actual line is greatly reduced, and the static elimination device can be arranged at an appropriate position to perform an accurate static elimination.

Moreover, a sharp portion is formed at the tip of the discharge electrode.
Since it is formed, a sufficient static elimination effect can be obtained
You.

Further, a sharp portion is formed at the tip of the discharge electrode.
The formation of two places enhances the static elimination effect.
Can be.

Further, since the gas to be ejected always passes through the inside of the discharge electrode, it is possible to prevent dust from adhering to the inner surface of the discharge electrode, and furthermore, the outer surface of the discharge electrode is made of an electric insulator. By being covered with the insulating coating layer, insulation between the discharge electrode and the ground electrode can be improved, and adhesion of dust to the outer surface of the discharge electrode can be prevented. Therefore, it is possible to maintain good static elimination performance over a long period of time, simplify maintenance of the discharge electrode, and greatly extend the maintenance period .

The insulating coating layer is 2 mm from the tip of the discharge electrode.
The electrode and the worker can be protected by being projected in the gas ejection direction in the following range.

A cable fixing mechanism for fixing a high voltage cable for supplying a high voltage from a high voltage power supply to a casing constituting a ground electrode, a high voltage joint for electrically connecting the high voltage cable and the discharge electrode, and a gas supply Since the tube fixing mechanism for fixing the tube is integrally provided, the static eliminator can be compactly integrated .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a static eliminator showing an embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along line II-II of FIG.

FIG. 3 is a partially cutaway perspective view showing the tip shape of a discharge electrode in detail .

4 is a cutaway perspective view partially showing a modification Katachirei the tip shape of the discharge electrode.

[Explanation of symbols]

 (1) Discharge electrode (1a) Gas passage (1b) Gas outlet (1c) (1d) Sharp part (2) Casing (ground electrode) (3) Cable support (support block) (4) Tube support (Support block) (5) (6) Hole (7) Electrode support (Support pipe) (9) Insulation coating layer (11) Tube connector (12) High voltage cable (13) Joint pin (15) Air joint (16) Air tube

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-47488 (JP, A) JP-A-4-370697 (JP, A) JP-A-5-47490 (JP, A) JP-A-2-47 284396 (JP, A) JP-A-6-37121 (JP, A) JP-A-59-142156 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B08B 5/02 B08B 6 / 00 H05F 3/04 H05F 3/06 H01T 19/00 H01T 19/04 B67C 3/00

Claims (6)

(57) [Claims] A discharge electrode, a ground electrode, and a gas ejection mechanism, wherein ions generated by corona discharge between the discharge electrode and the ground electrode are sprayed on an object to be neutralized by a gas ejected from the gas ejection mechanism, thereby eliminating static electricity. In an ionization static eliminator configured to perform static elimination of an object, a discharge electrode is formed in a hollow shape with an electric conductor, and a gas passage of a gas ejection mechanism having a gas ejection port at a tip portion is formed inside the discharge electrode. And a sharp part at the tip of the discharge electrode.
An ionization static eliminator equipped with a gas ejection mechanism, wherein a gas is formed . 2. The discharge electrode has two sharp portions at its tip.
2. A gas ejection mechanism according to claim 1, wherein
An ionization static eliminator equipped with: Wherein the outer surface of the discharge electrode and being covered with an electrical insulator made of an insulating coating layer according to claim 1 or 2
Ionization static eliminator equipped with a gas ejection mechanism. 4. The insulating coating layer is 2 mm from the tip of the discharge electrode.
The ionization static eliminator provided with a gas ejection mechanism according to claim 3 , wherein the ionization charge removal device is projected in the gas ejection direction in the following range. 5. outwardly good electrical conductors made of the casing of the discharge electrodes are arranged, the ionization static eliminator having a gas ejection mechanism according to claim 1 or 2, characterized in that the ground electrode is constituted by the casing. 6. A cable fixing mechanism for fixing a high-voltage cable for supplying a high voltage from a high-voltage power supply to a casing constituting a ground electrode, a high-pressure joint for electrically connecting the high-voltage cable and the discharge electrode, and a gas. The ionization static eliminator according to claim 5 , wherein a tube fixing mechanism for fixing the supply tube is provided integrally .