| 摘要 |
PURPOSE:To make possible the optimum temp. control of metal strip in the slow cooling zone of a continuous annealing furnace, by setting the number of revolutions of a blower in accordance with the estimated value of heat quantity which the metal strip loses while passing the slow cooling zone of the continuous annealing furnace, and by correcting the number of revolution in accordance with other measured values. CONSTITUTION:The heat quantity taken away from metal strip with air while the strip passing a slow cooling zone is estimated by using a formula for calculating heat quantity, the formula which includes the thickness, breadth, transferring speed of the strip, and the temps. of the strip at the inlet side and the outlet side of the slow cooling zone. The flow rate of air in a pipe required for making the strip attain desired temp. at the outlet side of the slow cooling zone is calculated by using a formula for calculating the flow rate of air in the pipe, the formula which includes said estimated heat quantity and the temp. of air at the inlet side of cooling pipe. The number of revolutions of a blower is set by using said required quantity of air, and is corrected on the basis of the values obtained by measuring transferring speed, temp. of the strip during operation, and air temp. Said formula for calculating air flow rate in the cooling pipe is corrected dynamically on the basis of these measured values. |
