SU736435A1 - Device for applying powder materials in electric field - Google Patents

Abstract

1. A DEVICE FOR DRAWING POWDER MATERIALS IN AN ELECTRIC FIELD containing a fluidized bed chamber with high-voltage electrodes placed in it, connected to a high voltage source, a ground circuit of the product and a powder material dispenser, which has that, in order to ensure the stability of the coating process on products of complex configuration, it is equipped with a current recorder, connected to the ground circuit of the product, and galvanically not connected with the sensitive element, the interaction vuyuschim particulate material to the dispenser. 2. The device under item 1 ,. This is because the sensing element is designed as a nonlinear optical device. .

Description

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The invention relates to a technique of applying polymer coatings to products in an electric field and can be used to obtain the insulation of low-power electric machines, preferably in automatic conveyor lines. A device for applying powdered materials is known, comprising a fluidized bed chamber with a porous partition, ionizers, a high voltage source, a device for feeding and withdrawing powder, made with injectors. connected by means of pipelines with spray nozzles, and screening nets mounted above the powder extraction device. The disadvantage of this device is that it does not provide for maintaining - a constant concentration of particles in the fluidization chamber, due to which the particle charge varies considerably and makes it unstable the process of applying. . Closest to the proposed. is a device for applying. powder materials in the electric field, containing a fluidized bed chamber with non-high-voltage electrodes connected to a high voltage source, a ground circuit from the material and before the powder material jam. The disadvantage of this device is that continuous feed / powder without taking into account its actual quantitative demand and mechanically removing excess powder from the top of the fluidized bed does not allow maintaining a constant charge density of the cloud of charged particles near the printed product, which is especially It is important in the case of the deposition of powder on products of such a complex configuration as are the stators and rotors of electric machines with closed closed grooves. As a result, in a known device the stability process is violated, which prevents it from being used in automatic mode. The aim of the invention is to increase the stability of the coating process on products of complex configuration. This goal is achieved by the fact that a device for applying powder materials in an electric field, containing fluidized bed chambers with high-voltage electrodes connected to a high voltage source, an earthing circuit of the product and a powder metering device, is included in the current recorder; in the ground circuit of the product, and galvanically unrelated to Him unrelated sensing element, interacting with the dispenser of powder material. ... ;. / At the same time, the sensing element is made in the form of a nonlinear optical device. The drawing schematically shows the described device. The device contains a fluidization chamber 1 with a porous bottom 2 separating it from the chamber 3, a screw metering device 4, equipped with a control circuit including an amplifier 5, a switch 6 and p, barely time (not shown), and a high source voltage 7. In the lower part of the pseudo-liquefaction chamber 1, high-voltage electrodes 8 are placed, connected to a high voltage source 7, to the grounded output of which is a 9 dp suspension mounted at the top of the fluidisation chamber. A current recorder 11 is connected to the grounding circuit 10, as which a micrometer meter with light illumination of the scale is used. A nonlinear optical element, a photodiode i2, connected to the control circuit of the screw metering unit 4 through the amplifier 5, is fixed above the scale. The device works as follows. In the fluidization chamber 1 of the dispenser 4 pour a portion of the powder, which is. The transfer to a fluidized state is achieved by supplying air under the porous bottom. The powder is taken in such an amount that the layer above the electrodes in a fluidized state is 10-12 mm. When a high voltage of 40-50 kV is applied to the high-voltage electrodes 8 from the high voltage source 7, the charged particles of the powder material rush along the power lines to the grounded stator suspension 9, penetrate deep into the slots and deposit on their surface. The specified mode parameters provide high-quality coverage and uniformity. In the process of applying a stator to the ground circuit of the stator, a current flows due to the transfer of charge by particles and deposition on the coated surface. This current is recorded by microammeter 11, its value in the normal mode is 15-20. MCA. According to Mei5e, the powder consumption decreases its level above the electrodes 8 and at the same time the current in the ground circuits of the suspension 9 starts to grow due to the appearance of an ionic component in it. The current increase is detected by microammeter 11, and at the moment when the level of the powder layer above the electrodes 8 drops from the initial 2-4 mm, and the arrow on the scale of the microammeter 11 shows 25 µA, the photodiode 12 triggers, the signal from which goes through the amplifier 5 to switch 6 The latter gives a co35 4. manda for turning on the dispenser 4, the next portion of the powder enters the fluidization chamber 1, and its level above the electrodes 8 returns to its original position. The electrical parameters of the floor are restored, c. by virtue of which the arrow on the scale of the microammeter 11 also returns to its original position. After 20–40 s (this time is determined experimentally), the time relay triggers, and dispenser 4 is turned off. The fluctuation of the fluidized bed level above the electrodes 8 is 2 mm, which has practically no effect on the stability of the application process. The proposed device allows powder to be supplied to the keme. Fluidization in strict accordance with the requirements of maintaining a constant optimum parameters of the electric field, which determine the qualitative application of powder, especially on products of complex configuration, and makes it possible to use a device for applying powder materials in automatic mode.

Claims (2)

1. DEVICE FOR THE APPLICATION OF POWDER MATERIALS IN AN ELECTRIC FIELD, containing a fluidized bed chamber with high-voltage electrodes placed in it, connected to a high voltage source, the product grounding circuit and a powder material dispenser, characterized in that, in order to increase stability the process of coating products with complex configurations, it is equipped with a current recorder included in the product grounding circuit and galvanically unrelated to it with a sensitive element interacting with wort powder material. 2. The device according to p. Characterized in that the sensitive element is made in the form of a nonlinear optical device. . . ® SU. ,,. 736435