| 摘要 |
PROBLEM TO BE SOLVED: To prevent the generation of coating defects that are caused when a powder floating around a powder nozzle adheres to the nozzle, or the like, to become a molten drop at the time of the application of powder coating to the inner surface of a pipe. SOLUTION: A powder coating apparatus is formed into an integrated triple structure by a sheath pipe 3 covering a part of the rear portion of a powder nozzle 1 or the whole of a lance 2, and an annular space formed by the inner peripheral surface 31 of the sheath pipe 3 and the outer peripheral surface of an outer pipe 22 of the lance 2 is set to a reflux circuit 23 communicating with a suction device 4 generating air streams in the direction reverse to the feed direction of powder paint P. Adhering paint or floating powder paint ready to adhere is always removed by air streams in the direction always sucking air around the powder nozzle. If a structure making the axial line C1 of the lance 2 eccentric downwardly with respect to the axial line Cs of the sheath pipe 3 is set, the excessive flow of air under the powder nozzle is suppressed even in a suction state not only to minimize the influence on a coating pattern but also to obtain balance enhancing the removal effect on adhering paint.
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