Secondary Cooling Device The secondary cooling device, otherwise called as spary-rinsing tubes, is mounted right below the crystallizer. The spray-rinsing tubes are in the shape of an arc. The secondary cooling device is comprised of nozzles of different model and flow rate, carriage, flexible tie-in, and fixation block. The fixation block and carriage are inside the secondary cooling room. The upper part of the arc-shape rinsing tubes is inserted into the flexible tie-ins while the tie-ins are sealed by the sealing ring. The molten steel is turned into billets through first cooling in the crystallizer. The fresh billet shell is usually 8-15mm thick when it is withdrawn from the crystallizer, and it still has molten steel core inside the billet shell. For better solidification and withdrawal of the billets, the continuous casting machine is equipped with secondary cooling device and guidance device. The secondary cooling device is controlled automatically.
The cooling strength has a great influence on the billet quality, such as central star cracks, center segregation, and looseness. The secondary cooling device cools the billets from top to bottom, and the cooling strength is from strong to weak. Different billet type should be cooled at different strength. The nozzles for the secondary cooling device are atomization ones with the advantage of high jetting speed, complete atomization, high cooling efficiency, large coverage area, and cooling evenness.