Continuous Annealing Line (CAL) by United Enterprises is a continuous annealing process which integrates seven processes of un-coiling, welding, heating, annealing, cooling, shearing, and coiling.
After cold rolling, continuous annealing lines (CAL) are utilized to soften the material.
The Continuous Annealing Line (CAL) provides continuous and reliable operation for high yield, with annealing process speeds up to 800 m/min and entry/exit speeds up to 1,000 m/min.
In contrast to the batch process, the continuous annealing of steel strip provides some undeniable quality advantages, particularly in terms of heating and cooling homogeneity.
Un-coiler: The Entry level Un-coiler uncoils the cold-rolled sheet so that it can be fed into the bridle roller and processed further.
Welding machine: The Welding machine enables continuous strip feeding by automatically welding two strips together.
De-greasing unit: This is where the strip is cleaned of residual rolling oil, iron dust, and other impurities. It begins with an alkaline solution spray cleaning and an electrolytic cleaning process, followed by brushing. The strip is then rinsed with hot water to remove the solution before being dried with hot air.
Entry Accumulator: The strip looper compensates interruptions in strip feeding such as welding the coils together. A vertical or horizontal accumulator is created to meet the needs of the client to maximize space utilization.
Annealing Furnace: The Annealing Furnace heats the strip to between 750 and 850 °C. This is the temperature range required for re-crystallization of formed and solidified grains. The oxides on the surface are also reduced by annealing. The strip is cooled in stages to approx. 460 to 480 °C after it has been properly annealed.
Ammonia Cracker: The Ammonia Cracker is used to provide an inert reducing atmosphere inside the Annealing Furnace. The capacity of Ammonia Cracker used is 60 Nm3/Hr.
Exit Accumulator: A Vertical or Horizontal accumulator is also put at the exit area to enable uninterrupted operation even during maintenance or coil changes.
Coiler: The strip is continuously coiled into coils on a coiler when it reaches the end of the Continuous Annealing Line (CAL), and then is transported away.
||Length ~50m to 120m
||Annealing of low carbon & SS sheets
||680°C to 1080°C
||(0.250 to 5.0) MT/Hr.
||(200 to 950) kW
||400V - 50/60 Hz - 3 phase
||(0.1 to 2.0) mm
||300mm/ 550mm/ 1100mm