Study on the uniformity of internal flow field of air knife

Abstract The uniformity of the flow in the air knives play a crucial role for the quality of the galvanized anti-corrosion coating. Simulations of the flow are carried out to study the uniformity. To simplify the simulations, the air knife is segmented into two parts: the ends- and the periodic-segments. The velocity, vorticity, and turbulent kinetic energy both around the air distribution plates and the outlet are analyzed. Results show that the uniformity in downstream of the air distribution plates is higher in the periodic segment than that in the ends segment. While the uniformity around the outlet is found similar in the ends- and the periodic- segments. When the opening degree of the knife lip decreasing, the uniformity increases in downstream of the air distribution plates and decreases around the outlet. In such way, the present study sheds some light for the internal flow field of the air knife, and provides technical support for the design of air knife.