| 摘要 |
PURPOSE:To control cooling rates to desired values together with target temps. by regulating the flow rate of refrigerant by control valves and the number of nozzles in accordance with the relations between parameters in injecting refrigerant from nozzles to materials to be cooled. CONSTITUTION:A hot strip 10 is cooled by the steam and water injection from nozzes 12, 14.... A flow rate transmitter 32, a flow rate control valve 34, and if necessary, a shutoff valve 36 are inserted to a water supply pipe 22. The same holds true of other nozzles. The quantity of water Qi of one piece of the nozzle is determined by the equationI(leo is the effective cooling length per piece of the nozzles, b is the length of the nozzle in the width direction of the strip 10, rho, Cp, h are the density, specific heat and thickness of the strip 10, CR is a cooling rate, K is a constant, G: the density of wind flow, Tw is a water temp., Tg is the temp. of the strip, alpha-delta are constants), and the number of nozzles N in the transfer direction injecting the quantity of water Qi is determined by the equation II (Ti, To are cooling start and end temps., v is the transfer speed of the strip 10). |
