SU887012A1 - Apparatus for electrostatic depositing of powder-like materials on cylindrical article inner surface - Google Patents

Description

According to the invention, molded along the axis of the product, a reflector, rigidly connected to the end of the electrode, sonlon, iodachi and powder suction system and source of high penetration, and the reflector - in the form of a hollow para oolic body and mounted from the spray nozzle at a distance equal to the diameter of the workpiece, while the electrode cavity and the reflector are interconnected.

The form of the reflector is made in accordance with the dependency:

 X

at TP at 9th ZOH,

2 d

where b is the gap between the product and the maximum diameter of the reflector. RX is the radius of the circle on the reflector surface at point A; D is the diameter of the workpiece;

X - coordinates of the plane of the cross section of the reflector from its top along the axis of the electrode.

FIG. 1 shows a general view of the device; in fig. 2 - reflector in a larger scale.

The device comprises a desoldering unit comprising a metal body 1 with an insulating sleeve 2, a metal high-voltage electrode 3 with a reflector 4 rigidly fixed at the end, made in the form of a hollow parabolic body of dielectric material, a nozzle 5. The atomizer is attached to the rod 6 with centering supports 7. Device also contains a powder supply system 8, a system of suction of an unsettled powder with an inlet 10, and a source of high voltage I.

The device works as follows.

Parabolic shape of the reflector 4

selected by Rx / X

in accordance with the diameter of the product to be coated 12. The reflector is removed from the nozzle 5 at a distance equal to the diameter of the product to be coated. The reflector is fixed at the end of the rod 6 and is inserted into the stationary product 12, which is located on the wheel roller table (not indicated in the drawing), over its entire length and with the help of ball bearings 7 is centered along its axis. From the high voltage source 11, the high voltage electrode 3 is energized. An air-powder mixture is fed from supply system 8 to the sprayer and divided into two streams. One flow passes through the gap between electrode 3 and insulating sleeve 2. Here, between electrode 3

A corona discharge field is created in the housing 1, where the powder particles are charged and out of the atomizer through the nozzle 5. The second stream passes inside the electrode 3 and the parabolic reflector 4, where the powder particles acquire charge by contact and are directed toward the first stream, b the deposition chamber formed by the nozzle

5, a parabolic reflector 4 and the product 12 to be covered, the oncoming flows of the air-powder mixture form a vortex field, as a result of which the powder is in a suspended state of the SRI, and between the grounded product 12 and the high-voltage electrode 3 an electric field is formed, under the action of which the charged Powder particles are deposited on the surface of the product. 12. Unsettled

Powder particles through the inlet 10 of the suction system 9 are fed in to the powder supply system 8. Article 12 in the process of spraying, having made a rotational-translational motion on the roller table,

comes down from the rod 6 and thus the entire inner surface passes through the deposition zone successively.

The use of this device allows to increase the powder deposition rate by 20% -227 °,

get a coating more uniform in thickness; the spread of coating thickness is reduced by 2 times.

Claims (2)

1. A device for electrostatic spraying of powder materials on the inner surface of cylindrical articles, containing a sprayer with a nozzle and an electrode installed in it, made in the form of a body of rotation and placed along the axis of the product, a reflector rigidly connected to the end of the electrode, a powder supply and suction system and A high voltage source, characterized in that, in order to increase the powder deposition rate and ensure uniform coating, the electrode is hollow, and the reflector is in the form of hollow parabolic body and installed from the nozzle of the sprayer at a distance equal to the diameter of the workpiece, while the electrode cavity and the reflector communicate with each other. 2. The device according to claim 1, characterized in that the shape of the reflector is made in accordance with the dependence R ,.) at 0 | -2S-f, where R (x) is the radius of the circle on the outer surface of the reflector at 65 points X; D - X - b - 56 diameter of the item being processed - Sources of information, whether; the coordinates of the sectional plane of the reflector from its tip no1, taken into account during the examination. USSR Copyright Certificate axis; 5 No. 584900, cl. On 05B 5/08, 1972. the gap between the product and the area of the reflector, having a max-2. USSR author's certificate the maximum diameter. № 187562, cl. In 05B 5/06, 1965 (prototype). 887012