Abstract：In order to solve the problem of black spot defect on the surface of the strip after cleaning, which was caused by the degreasing agent level drop, the degreasing agent residue, the bubbling and sol- gel of degreasing agent. By site investigation and analyzing the occurrence of leakage based on the field test and putting forward the concept of adding the overflow valve on overflow pipe was put forward based on the site investigation and analysis of the occurrence of leakage. And after the optimization, the rate of the degreasing agent level drop was decreased from 0.12%/s to 0.02%/s (cleaning speed of 500 m/min). Through the establishment of a pollutant model, the residual oil and residual iron contents in the degreasing agent under different working conditions were quantitatively calculated. And then the optimal amount of the degreaser emission and defoamer addition was determined. A calculation model of degreasing agent content in the hot water rinsing system was established. It was concluded that the discharge of the desalted water in the hot rinse section should not be less than 11.47 m3/h. Through the above measures, the black spot defect on the surface of the strip after the high- speed vertical cleaning was successfully solved.
2018, Vol. 28 
