What is the influence of the nozzle Angle on the thickness of galvanized layer?How?
Generally, the working range of the spray Angle of the nozzle is between 0 and 10, while other factors remain unchanged, the coating thickness decreases with the increase of the nozzle Angle.Adjust the Angle of nozzle, must pay attention to, the injection Angle on both sides of the strip can't completely consistent, according to the experience, should be 10 ~ 2, because: if the same on both sides of the nozzle Angle, is the intersection of a plane just two strands of airflow on the strip, is beyond the airflow can produce spiral of strip width, the strip edge of normal zinc interference, resulting in uneven thickness, nodular edge defects.But, tell to the galvanized sheet of general use, always hope the plating layer of two sides of strip steel is same thick, and both sides gush blow Angle is unequal, can cause the difference of two sides of plating layer thickness, so in production practice, always let strip steel do not produce the principle of knot knot, shrink as far as possible, the difference of nozzle Angle of strip steel two sides.
Briefly describe the air cooling method of strip steel in hot galvanizing?
(1) air cooling of the strip before entering the first steering roller of the cooling tower: generally, two or more sets of vertical cooling bellows are set below the first steering roller, and some units are set between the top of the air knife and the vertical cooling bellows with multiple external cooling nozzles.In the production of thin specification strip steel, due to the small tension, in order to avoid due to the cooling bellows strong airflow caused by the jitter of the thin strip steel caused by the consequences of poor air knife spray effect, generally do not use vertical cooling bellows for cooling, here, mainly rely on the cold air nozzle above the air knife for cooling the strip steel.Only in the case of the thickness of 1.0mm strip steel, only the use of cooling bellows for cooling.
(2) horizontal cooling air cooling section at the top of cooling tower: after the first steering roller of cooling tower, 4-5 sets of cooling bellows are generally provided, each set of bellows has its own air supply system.The strip is guided by small idlers through each group of steel boxes in the horizontal cooling section, and the bellows are cooled by high-efficiency nozzles arranged up and down.