SU1452606A1 - Arrangement for applying thin-layer coating by electrostatic method - Google Patents

Description

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about:

The invention relates to electrospray spraying and coating devices and can be used to disperse solutions of metal compounds and produce active or protective metal or metal oxide covers on surfaces of grounded metal. 1 Line transported by a conveyor.

The purpose of the invention is to increase the uniformity of coatings from solutions containing metal salts, reduce the loss of sprayed material and increase plant capacity.

FIG. 1 shows an electrostatic thin layer coating device; in fig. 2 - device variant; in fig. 3 shows the node I in FIG. 2

A device for applying thin layer openings contains a container 1 for liquid i pacTBOpa), a sprayer in the form of a capillary 3, a isolator {) isolated from the capillary 3, a focusing electrode 4 and a high-voltage source 5 connected to it via a hose 2.

The capillary tube 3 is made of a dielectric material, for example polypropylene, the focusing electrode 4 is made in the form of a metal cylinder coaxially located relative to the capillary 3 mounted on the holder 5.

One of the poles (negative) of the voltage source 5 is electrically connected to the focusing electrode 4 and is connected to the liquid in the tank 1. The other pole (positive) of the voltage source 5 is ground. The workpiece 6 is installed (woven on the conveyor 7 and grounded.

In the case of FIG. In the second version of the device, the nebulizer is made in the form of a tube 8 with a capacitance 1 of 1, in the side wall of which there are installed capillaries 3, each of which has a focusing electrode 4 mounted on a tubular holder of a dielectric material A gap t | cabin 8 with capillaries 3, each focusing electrode 4 is electrically connected to the ungrounded pole of the voltage source 5.

At the ends of the holder 5, high-voltage insulators 9 and nuts 10 are installed, which are part of the screw drive 11 of the vertical movement of the sprayer (not shown).

The device for applying thin coatings works as follows.

The dispersible liquid from the tank 1 under pressure enters the hose 2 into the tube 8 and then is distributed through the capillaries 3 with the outlet diameter of 0.3 mm, leaves the capillaries 3 with a volume velocity of 0.01-0.5 directed to the surface processed product moved by conveyor.

At the time of a steady flow of fluid through the capillaries 3, the focusing electrodes 4 and the capacitance 1 are supplied with a voltage of 50-100 kV from the source 5. At the same time, the liquid acquires an electric charge, disperses to form a unipolarly charged fog, which, under the action of an electrostatic field deposited on the surface of grounded products.

The implementation of capillaries from a dielectric material contributes to the formation and stabilization of a dispersible liquid drawn in jets of an electric field, the elimination of corona discharges and secondary effects of corrosion, which allows an increase in the operating voltage and performance of the device. The connection of the focusing electrode with the non-grounded pole of the voltage source causes the creation of similarly charged air particles around liquid streams flowing out of the capillaries, which contributes to an increase in the degree of dispersion of the aerosol and to an increase in the uniformity of the coating.

Making the sprayer in the form of a tube, in the side wall of which there are capillaries with focusing electrodes and providing it with a drive of reciprocating movement in a vertical plane, makes it possible to apply the coating with a wide front with uniform distribution along the height of the product.

The invention allows to obtain coatings of ruthenium and titanium salts with a thickness of about 2 microns with a deviation from the average thickness of ± 0.3 microns.

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Claims (2)

1. DEVICE FOR APPLICATION OF THIN-LAYER COATINGS BY ELECTROSTATIC METHOD, containing a liquid container, a spray gun in communication with it, including a capillary and a focusing electrode isolated from the capillary in the form of a metal cylinder with a rounded edge coaxially relative to the capillary and one of which is supplied with a high voltage source under one of the voltage fields to the liquid, and the other is grounded, characterized in that, in order to increase the uniformity of the coating from solutions containing metal salts, reduce losses dusted material and increase the productivity of the device, the capillary is made of dielectric material, and the focusing electrode is electrically connected to the ungrounded pole of the voltage source. 2. The device according to π. 1, characterized in that the device is equipped with a reciprocating drive in the vertical plane of the atomizer, and the atomizer - additional capillaries with focusing electrodes, while the atomizer is made in the form of a tube connected to the tank, in the side wall of which there are capillaries, and covering the tube with a gap a holder made of a dielectric material in which the focusing electrodes are mounted. 4 ^ SP u f f