METHOD FOR FORMING SPRAYED COATING ON INNER SURFACE OF METAL TUBE, AND THERMAL SPRAYING GUN AND THERMAL SPRAYING APPARATUS FOR FORMING SPRAY COATING

摘要

PROBLEM TO BE SOLVED: To considerably increase the corrosion resistance and durability by depositing, in place of a conventional vinyl chloride lining, a sprayed coating on the inner surface of a metal tube having a diameter of ≤450 mm used for water supply pipes in general homes and buildings.;SOLUTION: An angle is formed between a torch and a sprayed coating forming surface by bending the torch 2 side of a thermal spraying gun 1. A wear resistant coating layer 36 is formed on the inner surface of a bent portion of a powder feed pipe 5 in the inside of the thermal spraying gun 1. The torch 2 is cooled with water. The powder feeding apparatus 15 comprises a powder chamber 16, a gear 17, a variable motor 18, a powder charging port 19, a carrier gas inlet 20, a vibrator air inlet 21, a powder discharging port 22, and a powder feeder 23. The film is deposited by using nozzles 4 of the plurality of thermal spraying guns 1 in a manner displaced like comb teeth or by making the thermal spraying guns 1 face each other from openings at both ends in the long metal pipe 5.;COPYRIGHT: (C)2002,JPO