METHOD FOR COATING THE INNER SURFACE OF LONG TUBER OF SMALL DIAMETER

摘要

A copper alloy condenser tube of small diameter is coated internally by inserting a spray nozzle(12) connected to coaxial inner(14) and outer hoses(15) that supply paint and compressed air, respectively. The nozzle is then retracted while spraying the paint at a predetermined speed. The inner hose for the paint is compressible using compressed air in the outer hose and is restorable when the pressure is released. The double hose(11) can be fed out from a drum by a pair of pinching rollers to prevent slackening in the hose.