Laminar Flow Cooling Behavior of Wide Heavy-thickness Coils

摘要

The modification of the bottom headers increases the capacity of the laminar flow system to cool wide heavy-gauge coils without inducing a canoe shape. Installation of sand filters and header caps provides convenience to maintain cooling efficiency. The ratio of the bottom flow to the top laminar flow has a significant impact on the transverse shape, i.e., canoe and crossbow. For a mill with an upcoller, increasing the flow ratio can reduce canoe. The calculated result displays: Control of canoe or crossbow is very sensitive to adjustment of the laminar flow ratio for the early banks because the critical temperature differences are smaller. Canoe shape will disappear when the ratio of laminar flow is over 1.5. However, even if its value is much greater than 1.5 and crossbow appears at the ROT, the CTL processor has the capability to correct it. Mechanical properties of wide heavy-gauge coils can be adjusted through selection of proper laminar flow pattern, cooling rate, and temperature difference between finishing and cooling.