AUTOMATIC ANTI-CORROSION COATING PROCESS AND PRODUCTION LINE FOR LARGE SIZE STEEL PIPE

摘要

Automatic anti-corrosion coating process and production line for large size steel pipe are provided. The coating process involves placing steel pipe on a steel pipe transmission mechanism, the steel pipe is subjected to dehumidifying and dirt separating, surface treatment and preheating, and then it is sprayed with coating, the coated pipe is cured and cooled, wherein the coating is heated before it is sprayed onto the surface of steel pipe, the heated temperature is between curing temperature of the coating minus 40℃ and curing temperature of the coating minus 20℃ which is same to the preheating temperature of the steel pipe; the production line includes steel pipe transmission mechanism, dehumidifying and dirt separating machine, automatic shot-blasting machine and preheating chamber, the automatic shot-blasting machine is arranged between the dehumidifying and dirt separating machine and preheating chamber, it is characterized in that coating cure unit is positioned behind the preheating chamber, the coating cure unit consists of spraying chamber, coating cure chamber and cooling chamber which is arranged in a line in turn, and there is spraying machine for spraying coating onto the surface of steel pipe in the spraying chamber, the spraying machine is connected with automatic heating apparatus for coating. And the coating cure chamber is provided with hot air recycle system. The coating process is automatically performed through a production line, and it provides high production efficiency and good coating quality without environmental pollution.