Hot Dip Galvanizing Line and Galvalume Line (for Strip Steel)
The hot dip galvanizing line or galvalume line is where a layer of zinc coating or zinc-aluminum coating is applied to the surface of cold-rolled steel plate through a process known as hot dipping. The resulting steel plate exhibits enhanced corrosion resistance and obtains a more attractive surface. The galvanizing equipment typically involves treatments such as degreasing, annealing, chemical reduction, hot-dip galvanizing or galvalume, and fabrication.
Hot dip galvanizing line, one of our most popular coil processing lines, is widely used method of protecting metals from rust. The corrosion protection method for steel generally takes two forms: in-situ and ex-situ. During the in-situ annealing process, the cold- or hot-rolled coil steel has its grains in the lattice structure re-arranged. This recrystallization annealing process is done in a protective atmosphere of nitrogen, hydrogen and water vapor. After that, the annealed steel is dipped into a pot of molten zinc or zinc-aluminum to receive a protective coating.
Processes that are similar to what is described above include the Sendzimir Process, Modified Sendzimir Process, and UEC Hot Dip Galvanizing Process. The above process is essentially a variation on the UEC process.
At our hot-dip galvanizing line and galvalume line, the original coil stock is firstly uncoiled, subsequently goes through cleaning, annealing, galvanizing or galvalume, chromizing, and oiling processes, and finally rewound to form finished products.
According to the process requirements, the whole hot dip galvanizing line or galvalume line is divided into seven sections. At each section, the steel strip needs to be tightly stretched. The continuous galvanizing line or continuous galvalume line can also be split into three working zones, each for uncoiling, processing, and rewinding.
Donghe Compay has accumulated much experience after working with the strip processing line for over a decade. All our technicians are working at the forefront of product design and manufacture, taking responsibilities and have opportunities to get the hands on experience. Most of our technical specialists have been working in the hot dip galvanizing line industry for eight years. From design, through manufacture, to installation and after-sales service, our men take responsibilities for all the processes to ensure customer needs are satisfied. Throughout the years of production, we have patented our 5 partition cooling system for the continuous annealing furnace. This cooling system can blow air evenly across the furnace.
Main Application Areas
Our hot dip galvanizing lines and galvalume lines are widely used for steel processing in industries such as automobile, construction and household appliances.
Process Flow of the Hot Dip Galvanizing Line / Galvalume Line
Coil Car—Pay-Off Reel—Pinch Roll—Shear—Welding Machine—Material Storage Device—Steering Roll—Bridle Roll—Cleaning Unit (including the brusher roll, cleaning system, chemical degreasing, electrolytic degreasing, and squeegee roll) —Hot Air Blowpipe—Steering Roll—Bridle Roll—Tension Meter—Annealing Furnace—Thermal Tensioner—Annealing Furnace Bull Nose Section—Pot of Molten Zinc / Aluminum-zinc —Three Rolls with Six Arms—Air Knife—Cooling Tower—Deflector Roll—Air Cooling Device—Deflector Roll—Water Cooling Device—Hot Air Blowpipe—Steering Roll—Bridle Roll—Skin Pass Roll—Bridle Roll—Tension Leveler—Bridle Roll—Passivation Device—Drying Oven—Bridle Roll—Material Storage Device—Bridle Roll—Electrolytic Oiler—Shear—Pinch Roll—Rewinder—Coil Transfer Car
Major Coil Processing Equipment for Composing the Hot Dip Galvanizing Line / Galvalume Line
The annealing furnace used for consisting of our hot dip galvanizing line has a key role to play in the production process. It is comprised of the pre-heating section, heating section, uniform heating section and rapid cooling section.
The tension leveler is a piece of strip steel finishing equipment. It stretches, bends, and straightens the strip, thereby eliminating edge wave, coil set, cross bow, camber, and a combination of defects. The result is that the steel strip obtains improved quality.
Steel Storage Unit
The steel storage unit is an indispensable item in our coil processing line to ensure there is always enough stock of steel coil available for continuous production. According to different circumstances on the production line, this coil processing equipment can be made into floor-standing type or horizontal version.
During the continuous galvanizing or galvaluming process, the head of one carbon steel coil being loaded onto the production line needs to be welded to the tail of coil being processed by the line.
The electrostatic coating machine supports flexible control on the amount of oil to be applied to the steel strip surface. The oil amount varies in response to the speed at which the strip is moved, so that the oiling speed remains constant. The excess oil will be recycled.