論 文
スロットノズル先端角度のワイピング性能への影響
キーワード:
Impact Pressure,
Shear Stress,
CFD,
Jet Wiping,
Continuous Galvanizing Line,
Obtuse Tip Angle,
Weber Number
2015 年 15 巻 3 号 p. 217-224
詳細
2015 年 15 巻 3 号 p. 217-224
From the viewpoint of surface quality, the jet wiping method, that is a non-contact type, is used to control the coating thickness in a continuous galvanizing line. In this paper, in order to study influences of nozzle tip angles on the wiping ability, we conducted wiping tests using a wiping simulator and CFD analysis to examine the jet properties. Furthermore, we observed the shape of the liquid film in the vicinity of jet impingement. The wiping tests revealed that the nozzle tip angle had a large influence on film thickness. A thickness increase of approximately 20% was observed at a tip angle of 90° compared to 50°. But there were no changes in impingement pressures and shear stresses in both measurements and CFD analysis. On the other hand, the film shapes changed, becoming thicker when the tip angle was increased. Therefore, the change of liquid film thickness is inferred as the main reason for wiping performance changes by nozzle shape.
