RU1780844C - Sprayer for powder material - Google Patents

Abstract

Usage: in the technique of applying coatings of powder materials using pneumatic spraying. It can be mainly used to produce coatings on products of various industries with an increase in the deposition coefficient nopbiuKii / SUMMARY OF THE INVENTION: the atomizer is equipped with a compressed ionization device 1vb d7x a7 bp filled in the form of a needle-ring electrode system installed in each compressed air supply connected. . .-.... search engine. with an annular chamber formed by the inner surface of the casing and the outer surface of the powder-air mixture supply means connected to it, made in the form of a sleeve with a nozzle having an axial bore with a narrowing such as a Venturi nozzle. and screw channels on the outer surface of the sleeve. The channels are in communication with the annular chamber forming an air flow stabilizer. The dielectric element is made with screw ribs on the outer surface with pointed ends, the pitch of the screw of which is equal to the pitch of the screw channels of the sleeve and has the same direction with it. A third grounded electrode made in the form of a conductive rod with needle-shaped ends is isolated along the entire length inside the dielectric element, in addition, the inner end of the dielectric element is conical. When a high voltage of negative polarity is applied to the electrode, a corona discharge arises at its tip, which generates negative ions. These ions are picked up in the narrowing of the air supply channel by a stream of compressed air and carried into the mixing chamber through the tangential channel of the annular chamber and the screw channels of the sleeve during swirling motion. 1 s.p. f-ly, 3 ill. Yo H 00 About 00 fe

Description

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The invention relates to a technique for applying coatings of powdered materials by means of pneumatic throttling apparatus. It can be advantageously used, & zk & .gЈl- ™

but for the production of coating on the product

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various industries.

A device for applying coatings of powdered materials is known, made in the form of a sprayer containing a cylindrical body with a triboelectric powder charging unit, made in the form of coaxial and eazo mounted one relative to the other inner outer tubes, with a conductive element placed along a helix on the surface of the inner tube, on the end sections of which holes are made, 5 riches after the holes at the inlet and plugs are installed in front of them at the outlet.

The disadvantage of this device is the uneven distribution of powder in the air stream, the presence of ag-10 omerates from undivided powder particles.

A device for spraying and applying powdered materials, a housing, a hollow cylinder, a barrel for a triboelectric powder charging mounted therein, a butt plate with a channel for supplying a powder-air mixture made with a truncated conical cavity in of which 20 the initial part of the barrel is located, made with a conical divider and ribs passing to the cylindrical part of the barrel, located on it along a helical line and forming channels with a hollow 25 cylinder for the passage of powder and at the end of the end part of the barrel a parabolic recess is made with a fairing in the center, forming a mixing cavity with end sections of the ribs and the cylinder, a nozzle containing a lock washer, a movable cylinder and a tip with a braking element fixed in the confuser-diffuser region of the tip , and electrically connected collectors of conductive material, one of which is made in the form of a fitting and installed in the back plate, and the other in the form of rings installed in a hollow cylinder.

In this device, a triboelectric charge of particles of powder occurs when they move along helical channels of electrical insulation material. Moreover, the charge of the powder particles depends on the friction force on the dielectric surface, the duration of exposure to this force, and the physical properties of the powder material.

The main disadvantage of this device is the presence of zones of a possible 50 accumulation of powder and movement through channels of agglomerates of undivided particles. Such zones exist at the junctions of the ribs of the conical divider with the hollow cylinder and at the points of installation of the rings of the current-conducting collector.

The deposition of powder in these zones leads, as it accumulates, to detachment of large-sized agglomerates, to their inefficient charging when passing through

channels, to poor quality coatings and high consumption of powder, part of which is not applied to the part.

An electric atomizer is also known, which contains units for tribo-charging the powder and for additionally charging it in the corona discharge field, the charging device located inside the atomizer, comprising a dielectric nozzle with a high-voltage electrode located therein, a conical divider.

The disadvantage of this sprayer is the insufficiently efficient powder charging, which significantly affects the process of applying dispersed materials and the quality of the formed coatings.

The purpose of the invention is to increase the powder deposition coefficient.

This goal is achieved in that a powder material atomizer comprising a hollow dielectric housing, a dielectric element installed in the housing to form a gap between it and the tribo-charging housing, a chamber in communication with the powder-air mixture supply means at the inlet and an exit divider, the supply channel compressed air in communication with the chamber, two grounded electrodes mounted on the housing, a corona electrode with a needle-shaped end and a high-voltage source, the atomizer is equipped with ionization means compressed air, made in the form of a needle-ring electrode system installed in a compressed air supply channel connected tangentially to an annular chamber formed by the inner surface of the housing and the outer surface of the powder-air mixture supply means, made in the form of a sleeve with a nozzle having an axial hole with a narrowing of the type of Venturi nozzle, and screw channels on the outer surface of the sleeve, in communication with the annular chamber, forming an air flow stabilizer, while the dielectric the cured element is made with screw ribs on the outer surface with pointed ends, the screw pitch of which is equal to the pitch of the screw channels of the sleeve and has the same direction with it, and a third grounded electrode is made in the form of a conductive rod with needle-shaped ends along the entire length of the dielectric element in addition, the inner end of the dielectric element is conical.

In FIG. 1 shows a general view of the atomizer (cross section); in FIG. 2 - section aa; in FIG. 3 - section BB.

The atomizer consists of a grounded frame 1 (or the first grounded electrode), a hollow dielectric casing 1, installed in the casing 2 of the dielectric element 3 with the formation of sampling between it and the casing 2 for the powder powder and mounted on the Btfx6 # riuWf6p-dielectric casing 2 of the At cover

screws.

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Inside the dielectric element Evil, its entire length is insulated by a third earthed electrode 5, made in the form of a conductive rod with Lig / Toob1- at different ends.

At the outlet of the spray gun, cover 4 is mounted with a splitter 6 with the possibility of axial movement of the direct connection of the threaded connection to the current supply rod Ttshl with rod 5 and a set of washers 7. f

The inner end 8 of the dielectric element 3 is conical and oriented towards the second ground electrode - the inlet pipe 9 of the powder-air mixture. - “the outer surface of the dielectric element 3 is made vINTOSHE ribs 10 with pointed ends located along a helical line on its only cylindrical part and forming channels 11 of the powder-air mixture with the hollow dielectric body 2.

The inner conical end 8 of the dielectric element 3 is placed in the mixing chamber 12 and is designed to distribute the supplied powder to the periphery of the dielectric element St 3.

Hollow dielectric housing. .2 comprises an inlet end cap 13 for receiving the nozzle 9, means for supplying the powder-air mixture, and means for ionizing the compressed air.

The powder-air mixture supply means is made in the form of an axial from the opening 14 with a narrowing of the type of Venturi nozzle in the flange sleeve 15 with the nozzle 9. The sleeve 15 is coaxially mounted relative to the nozzle 9 with grooves located along the helical line on its outer surface, forming with a hollow dielectric body 2 screw channels 16 connected to the annular chamber 17 forming an air flow stabilizer. The annular chamber 17 is formed by mating recesses on the outer surface of the sleeve 15 and the inner surfaces of the housing 2 and the inlet end cover 13 with a tangential channel 18 for supplying ionized compressed air, tangentially connected to the annular chamber 17, while the pitch of the screw channels of the sleeve 15 is

Step Y Screw Kayal 11 Dielectric

e / gem EnTa 3 and have one direction.

Remedy for compressed air

made in the form of a threaded pipe 19c

Connection to the front cover

13 hollow body 2 and feed kayal 20

c) fbi j a v;:; j:; t ..i 1; .; ,,,,

Channel 20 pbd chi of compressed air (you-;

more complete with constriction 21. Prior to constriction 21, a grounded Electrode 22 is installed, and after

 narrowing Шк ТШнШв about; a 23 corona electrode 24 with a needle-shaped end for applying a high voltage to (KOTop OMY ot of a high-voltage source (on

not shown) cable 25 is connected. The corona electrode 24 and the grounded electrode 22 are a system of needle-ring electrodes.

The compressed air supply channel 20 is, as it were, a continuation of the tangential channel 18 and is tangentially connected to the annular chamber 17. L

Metal frame 1, tocopro (driving rod 5, powder supply pipe 9,

air-gas mixture and the electrode 22 are electrically interconnected and grounded to each other and are four grounded electrodes.

Powder atomizer operates as follows.

When a high voltage of negative polarity is applied to the electrode 24, a corona discharge arises at its tip, which generates negative ions. These

ions are picked up in the narrowing of the 2Ch1 channel

20, the air supply is carried by a stream of compressed air and is carried out into the mixing chamber 12 through the tangential channel 18, the annular chamber 17 and the screw channels 16 of the flange sleeve 15, while acquiring a helical vortex motion. ,,, -. - The flow of particles of the coating of the sprayed material, by entering 1 pipe 1 through the pipe channel 9 with an opening 14 of the type of Venturi nozzle

in the mixing chamber 12, the conical ends 8 of the dielectric element 3 and ribs 10 with sharpened inlet ends are developed, supplemented by ionized compressed air coming out of the screw channels 16 and sent to the screw channels 11 of the dielectric element 3.

Thanks to the screw channels of the dielectric element 3, the powder, together with the ions of compressed air, moves along

him, receives a vortex motion, as a result of which all sides of the powder particles are on; are saturated by air ions and enter into resistance with the walls of the charging channels, while acquiring a charge. Current-conducting rod 5 to accelerate the flow

the charge from the inner surface of the triboelements is electrically connected to the pipe 9 and the frame 1, from which the charge is removed to the ground.

At the exit of the channels 11, the charged rotating separate streams are broken by a splitter and, in the form of a uniform torch, are thrown out and applied onto the product to be coated.

In this way, an increase in the powder deposition coefficient is achieved.

Claims (2)

1. A powder material sprayer comprising a hollow dielectric housing, a dielectric element installed in the housing to form a gap between it and the triboelectric housing, a chamber in communication with the powder-air mixture supply means at the inlet and an output divider, the feed channel is compressed - air in communication with the chamber, two grounded electrodes mounted on the housing, a corona electrode with a needle-shaped END, and a HIGH VOLTAGE SOURCE, characterized in that, in order to increase the deposition coefficient  . "And in Fia j cradle, it is equipped with a means of ionization of compressed air, made in the form of a needle-ring electrode system installed in a compressed air supply channel connected tangentially to an annular chamber formed by the inner surface of the housing and the front end cover, and the outer surface mating with it means for supplying a powder-air mixture made in the form of a Venturi nozzle, and screw channels on its outer surface, in communication with the annular chamber, forming an air flow stabilizer, while the dielectric the element is made with screw ribs on the outer surface with pointed ends, the screw pitch of which is equal to the pitch of the screw channels of the sleeve and has the same direction with it, and a third grounded electrode is made in the form of a conductive rod with needle-shaped ends along the entire length of the dielectric element. 2. The sprayer according to claim 1, from scratch, so that the inner end of the dielectric element is conical. , Ј4 / 9 F fae. 2 6-6  Qjiccf / nhjl / Ja34% fjc