PLANT FOR TRIBOSTATIC SPRAYING OF POWDER POLYMER COATS Russian patent published in 2002 - IPC

FIELD: technology of applying powder-like polymer materials by means of pneumatic spraying for obtaining anticorrosive coats on machines and units of chemical industry. SUBSTANCE: plant is used for application of anticorrosive polymer coats on base of chemically stable thermoplastic polymers - fluoroplastics, pentaplastics and polyamides at chemical plants for protection of apparatus, reservoirs, agitators, fittings, pumps, fans, pipe lines, branches, T-pieces and other articles against aggressive media. Proposed plant includes powder feeder, two pairs of tribostatic sprayers made in form of guns, pneumatic equipment panel provided with four independent pneumatic distribution systems and switching-on unit. Feeder is provided with two bins built in it which are provided with four ejectors and two agitators. Tribostatic sprayers of first pair have housing made in form of hollow cylinder with electrizer mounted inside it and used for tribostatic charging of powder, quick-change nozzle and back plate with passage for powder-and-air mixture which is provided with inner cavity made in form of truncated cone where initial part electrizer made in form of two cylinders is located; cylinder of lesser diameter is interference fit inside larger hollow cylinder which is interference fit inside housing. Outer walls of both cylinders are provided with double-start helical passages for flow of air-and-powder mixture; at the butt of end section of barrel, parabolicrecess with tapped hole is provided for quick-change nozzle in center forming mixing cavity together with butts of electrizer cylinders and quick-change nozzle. Second pair of tribostatic sprayers has housing made in form of two round dielectric plates, electrizer mounted between these plates, quick-change nozzle, air passage, air-and-powder mixture passage and sprayer handle with microswitch. Electrizer is made in form of disk with spiral slots at their butts; beginning of these slots is connected with air- and-powder mixture passage running from center of electrizer to inlet pipe unions via handle; outlet of spiral slots are connected with air passage at angle of 52 deg. EFFECT: enhanced and smooth deposit of powder-like material without sinters; increased productivity; reduced danger for personnel engaged in this operation. 4 dwg