Research on an Environment-Friendly Automated Equipment Applied to Hot-Phosphating for Drill Collar Coupling Screw Thread

Based on the present situations and requirements of the hot-phosphating for the oil drill collar coupling screw thread, one type of environment-friendly automated equipment has been studied, the corresponding hot-phosphating process has been consummated and one new implementation scheme has been designed in which some key technologies such as total-closed circuit and autocontrol have been accomplished. Comparing with the open-type phosphating trough instrument, this equipment has total-closed structure in which all function solutions such as degreasing and descaling, surface conditioning, phosphating, passivation and cleaning can circulate continuously which means phosphating solution is easy to maintain and there is no pollution to it and its service life is prolonged accordingly, all that avoid the glaring drawbacks in open-style one. In addition, this device has low processing and operating cost, efficiency is high and the quality of the phosphating coat is reliable. Specially, there is no harm to environment and operators. And the control system is based on PLC which is applied usually in industrial control, it is easy to build and has reliable performance. The whole installation needs a low capital investment relatively and is operated and maintained simply and conveniently which implies a widespread application in drill collar coupling screw thread hot-phosphating.