Speaker
MICHEL DUBOIS
(CMI INDUSTRY)
Description
After some review of typical surface defects observed in CGL running at low speed and sometimes heavy coating, the solution of the Navier Stokes equation in that process window is analyzed and discussed. The liquid velocity profile is computed from NO wiping situation to classical wiping. The question of back flow in relation with line speed and coating weight is addressed. From the analysis, the max coating weight that can reached industrially on wide and smooth strip is proposed in relation with the line speed
The question of special behavior of the liquid back flow at the edge is also discussed with the impact on the surface quality of the final coating.
Finally, the liquid flow down after wiping is analyzed. The surface velocity as well as the flow are strongly depending on the coating thickness. A technological solution is proposed to minimize the impact of down flow on the finished product
Keywords
Galvanizing, wiping, low speed, surface defect, thick coatings
Author
MICHEL DUBOIS
(CMI INDUSTRY)