COOLING OF A METAL STRIP USING A POSITION-CONTROLLED VALVE DEVICE

摘要

In order to cool a metal strip (1), a liquid coolant (5) is supplied to said strip by means of a supply device (9). The coolant (5) is fed to the supply device (9) via a feed line (10). A valve device (13) is arranged in the feed line (10). By setting the valve device (13) to a respective opening position (s), the coolant flow (F) which is supplied to the metal strip (1) by the supply device (9) per unit of time can be adjusted continuously or in several stages. An upstream condition detection device (14) is located upstream of the valve device (13) in the feed line (10) and is used to detect an upstream condition (ZV) of the coolant (5) upstream of the valve device (13) in the feed line (10). A control unit (6) determines a set point (s*) for an opening position (s) of the valve device (13) corresponding to the set point (F*) for the coolant flow (F), on the basis of a set point (F*) for the coolant flow (F*), the upstream condition (ZV) of the coolant (5) and a valve characteristic (C) of the valve device (13). The valve characteristic (C) follows a characteristic curve (K) of the coolant flow (F) as a function of the opening position (s) of the valve device (13), relative to a reference condition (ZR) of the coolant (5) upstream of the valve device (13) in the feed line (10). The control unit (6) sets the opening position (s) of the valve device (13) according to the set point (s*) that has been determined.