PURPOSE: To perform more accurate controlling by applying the correction by the cooling effect of off nozzles upon the injection rates of refrigerant and effective cooling length calculated by model equations when controlling the cooling end point temp. and cooling rates for materials to be cooled to desired values.
CONSTITUTION: To control a high temp. strip 10 to a desired cooling rate CR* and a cooling end point temp. T*o, the water flow density W* and effective cooling length le* of the equationsI, II (ρ, Cp, h, u: the density, specific heat, thickness and speed of the strip 10, K: constant, G: wind flow density, Tw: water temp., Tg: wind temp. αWδ: constants, Ti: cooling start temp.) are set. here, if the le* is shorter than the cooling length lo, the nozzles 12, 14W on, for example, inlet side, are turned off, and gas of the extent of preventing overheating is flowed to these. Here, the equation III holds, and if the coefft. of heat transfer for cooling with the gas alone is defined as Hg, the Ti is lowered by the equation IV (Tx: the temp. of the strip 10 at the inlet of a cooler). This Ti is substituted in the equation II, whereby the le* is determined.
SANO YUUJI
RIYUURAKU NORIMOTO
SUEHIRO KATSUMI
