continuous hot dip galvanizing line
We provide carbon steel and alloy steel hot-dip galvanizing line which can produce sheet with small spangles or without spangles. The product has good performance of corrosion resistance and coating adhesion, it is widely used for manufacturer of automobile, household electric appliance, building construction and base plate for color coating etc.
The line consisted of an entry section with two uncoiler paths to the horizontal accumulator, a process section with a horizontal furnace with carry-over rolls to support the strip. The hot strip then progressed through the furnace exit snout into the molten zinc. The exit of the zinc was provided with an air knife with controlled airflow to remove excess zinc before passing through the cooling section to a skin pass mill, then through a leveller, a coater for anti-fingerprint laquer and into the vertical exit accumulator.
The process includes:
degreasing
annealing from furnace
zinc coating
quenching
shearing.
Galvanizing coating process begins with the cleaning of coil .it is done by de greasing process .this process contains alkaline liquid combined with brushing, rinsing and drying.
After this process the coil enters to the furnace for annealing process. in this coil is passed through various section which contains compostion of hydrogen and nitrogen to remove any oxide on the surface of coil.
At the exit of coil from the furnace , coil pass through snout. After this coil is immersed in the molten zinc pot where coating of coil takes place at particular temperature.
As the coil is withdrawn from the pot, high pressure knives is used to remove excess amount of zinc to control coating thickness. for better quality zinc pot composition analysis is done.
To achieve flatness and required elongation coil passed through skin pass mill or tension leveler line.
At the end chrome coating is done to prevent coil from white rust .
Mainly in various industries the annealing process of continuous galvanizing line is done by Non-ox furnace.
Non-ox Furnace:
This furnace includes various section:
PHF
RTF
SOAKING
JCF
Firstly the coil passed though PHF(PREHEATING FURNACE). In this burners are placed to provide fixed air gas ratio to enable an oxidizing atmosphere in the first zones .
Then the coil pass through RTF (RADIANT TUBE FURNACE).In this electrical heaters are placed that provide particular temperature to the coil. it contains annealing temperature in the presence of protective atmosphere of nitrogen and hydrogen. the temperature range between 550-750 deg celsius.
The coil is then go through soaking point to achieve desired properties. before entering the zinc pot
JCF(JET COOLING FAN) brings down the temperature of coil through
cooling fan. at the end coil enters the zinc pot and zinc coating takes
place.
Today many steels users and manufacturers automobiles and appliance inclined towards coated products.
*Your email address will not be published. Required fields are marked.