SU1725408A1 - Device to remove static electricity - Google Patents

Abstract

The invention relates to the removal of electrical charges using discharge devices and can be used in devices for neutralizing static electricity. The aim of the invention is to ensure the removal of static charges from photographic films without exposing them. The device consists of a crroning electrode, made in the form of a thin rod with an electrically conductive coating with a dendritic structure, connected to a source of constant or alternating high voltage, and the grounded electrodes are located on both sides of the high voltage electrode parallel to it at a distance approximately equal to the distance between the high voltage electrode and the charged surface. 2 Il.

Description

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WITH

The invention relates to the removal of electrical charges using discharge devices and can be used to neutralize static electricity on the surface of fabrics, sheets, films, mainly photographic films.

Various types of devices for neutralizing static electricity charges are used in which corona discharge is used. In these devices, electrodes for coronary discharge are usually in the form of wires or plates with pointed edges. Both a constant and alternating voltage of industrial or increased frequency can be applied to the electrode. The neutralization of the electrical discharge is carried out using a grounded electrode.

However, the effectiveness of such a neutralizer is low, because to excite

corona charge on the surface must have a sufficiently high potential,

It is also known a device in which, in order to increase the neutralization efficiency, the grounded needle corona electrodes are equipped with electrets with a polarity of charges on the working surface that coincides with the polarity of charges on the neutralized surface.

Also known are devices in which a part of the corona electrodes is grounded, and a part is connected to alternating or direct voltage generators, with the high-voltage electrodes located between the grounded electrodes. This also improves the neutralization efficiency, but it makes the device much more complicated, especially when it is necessary to install the necessary number of electrodes in a limited volume.

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Closest to the present invention is a device in which a static charge from a moving tape, which is a dielectric, is removed, passes a tape under a wire electrode, having the form of a rod with a diameter of 0.08 cm. The electrode is placed across the tape at a distance of 0.6- 8 cm from her. An alternating voltage of 3-10 kV with a frequency of 70 Hz is applied to the electrode. If necessary, a grounded electrode is placed parallel to the high-voltage electrode. The device is used to eliminate static electricity from plastic films, where an enamel wire is used as the high voltage electrode. This device is also provided with conductive elements connected to earth.

A disadvantage of the known device for removing static electricity is that it cannot remove static charges from the film, since the corona discharge causes the film to light up.

The aim of the invention is to enhance the functionality by providing for the removal of charge from the film without exposing it to the charge by reducing the electrical potential of the dark corona discharge.

The goal is achieved by using one or more corona wire electrodes in the form of rods arranged across the ribbon parallel to the neutralized surface. One of the electrodes is necessarily supplied with a high direct voltage of some polarity or alternating voltage. The remaining corona electrodes are grounded. One or two grounded electrodes are in parallel with a high voltage electrode from different sides of it and at a distance from it, approximately equal to the distance between the high voltage electrode and the charged surface.

All high voltage electrodes have conductive coatings of a dendritic structure.

Compared with analogues and prototypes, the proposed device is characterized by the presence of a conductive coating of a dendritic structure on the corona-carrying high-voltage electrodes, i.e. The surface of the wire of the high-voltage electrode is covered with random conductive dendritic needles, which contributes to the appearance of a dark discharge at a lower potential of high voltage.

Fig. 1 is a schematic diagram of the proposed device; Figure 2 shows electrodes with a conductive dendritic coating;

The proposed device consists of a corona electrode 1, made in the form of a thin rod coated with a conductive material. The electrodes are covered with a conductive material with a dendritic structure, connected to a source 3 of constant or alternating high voltage, and the remaining electrodes 2 are grounded and located on both sides of the high voltage electrode. Electrodes are housed in holders of dielectric material (not shown).

The device works as follows.

The corona electrodes 1 and 2 are arranged parallel to each other and the surface to be neutralized, across the movement of the ribbon 4. When the charged ribbon moves, a dark corona discharge appears near the surface of the electrodes, reducing the potential on the surface of the ribbon. When the tape passes under a high-voltage electrode, the potential on the tape decreases to less than 0.2 kV.

Were made of the corona electrodes of an alloy of nickel with chromium. The diameter of the electrode was 30 µm. A nickel-chromium alloy was taken to ensure the strength of the thin electrode. Electrode coating with a conductive carbon layer of a dendritic structure was carried out during pyrolysis of pentane vapor onto a heated to 1000 ° C electrode. The diameter of the coated electrode was 100 µm.

Tests of the device showed that when moving the film at a speed of 4 m / s and with an electrical potential on its surface of more than 25 kV, passing under a high-voltage electrode to which a constant voltage of 2.5 kV was applied, the potential decreased to less than 0 , 2 kV without any traces of illumination. The distance between the corona electrodes and the film surface was 10 mm.

The use of the proposed device for neutralizing static charge on photographic film during its production and exposure will ensure that static charge is removed to a safe value without mechanical damage and photo light.

Claims (1)

Invention Formula A device for eliminating static electricity from the surface of dielectric strips, including wire corona electrodes made in rods across the strip and parallel to its surface, with one of the electrodes connected to a high voltage source, and grounded electrodes are located on both sides of the high voltage electrode at a distance equal to the distance between the high voltage electrode and the grounded surface from l and IG Editor L.Gratillo Compiled by S.Hartov Tehred M. Morgental In order to extend the functionality by ensuring that the charge is removed from the film without exposing it by reducing the electrical potential of the dark corona discharge, the high-voltage corona electrode has an electrically conductive coating with a dendritic structure. 2 Proofreader M. Demchik