| 摘要 |
The surface appearance of a wire or tube coated with a liquid metal may be improved by the use of a gas jet wiping nozzle of defined shape to wipe excess molten metal from the wire or tube. The nozzle has an upper annular part and a lower annular part, each of the annular parts has an upper and a lower annular surface meeting in an annular edge. Adjacent surfaces of the upper and lower annular parts define between them an annular gas passage terminating in an annular gas orifice adapted to surround a wire or tube being wiped. The included angle between the upper surface of the upper annular part and the direction of travel of gas leaving the gas orifice being smaller than (80-x).degree. and the included angle between the lower surface of the lower annular part and the direction of travel of gas leaving the gas passage being smaller than (70+x).degree. where x is the included angle between a plane normal to the direction of movement of the wire or tube through the gas jet wiping nozzle and the direction of travel of gas leaving the gas passage. The lower surface of the lower annular part directly faces the liquid bath and is so disposed that the minimum included angle between that surface and the direction of movement of the wire or tube through the gas jet wiping nozzle is at least 20.degree.. The upper surface of the upper annular part is so disposed that the minimum included angle between the surface and the direction of movement of the wire or tube through the gas jet wiping nozzle is at least 10.degree.. |
