Method and coating device for coating a metal strip

Abstract

Within a coating device, a metal strip first runs through a coating container with a liquid coating agent and then a stripping nozzle device for stripping off excess coating agent from the surface of the strip. After the stripping nozzle device, the strip runs through a strip stabilizing device with a plurality of magnets on both broad sides of the strip. A form control deviation is determined as the difference between an actual form of the strip and a desired form of the strip and this form control deviation is used for activating the magnets in order to transform the actual form of the strip into the desired form. The magnets of the strip stabilizing device may be moved in the widthwise direction of the strip into a traversing position in relation to the magnets on the respectively opposite broad side of the strip.

1 . A coating device for coating a metal strip with a liquid coating medium, comprising:
 a coating container filled with the liquid coating medium;   a stripping nozzle device;   a strip stabilizing device with a plurality of magnets on the two wide sides of a slot of the strip stabilizing device;   at least one sensor for detecting the actual shape and/or or the actual position of the metal strip in the slot of the stripping nozzle device; and   a control device for determining a shape regulation difference as a difference between the actual shape of the metal strip and a predetermined target shape of the metal strip in a region of the stripping nozzle device and for controlling the magnets by way of a magnet actuator,   wherein the control device and the magnet actuator are further constructed to offset at least one of the magnets in dependence on the shape regulation difference in width direction of the metal strip relative to at least one of the magnets on an opposite wide side of the metal strip and displace it into a moved position where it is at least approximately opposite a trough in the actual shape of the strip.   
     
     
         2 . The coating device according to  claim 1 , wherein the control device and the magnet actuator are further constructed to displace the at least one magnet also in dependence on a position regulation deviation of the metal strip in width direction. 
     
     
         3 . The coating device according to  claim 1 , wherein the control device is further constructed to also control an actuator of a correction roller in such a way that the strip stabilizing device is operable within its operating limits. 
     
     
         4 . The coating device according to  claim 1 , wherein the control device is further constructed to also set a current (l) through the at least one magnet in such a way in dependence on the actual shape and/or the actual position of the metal strip that the target shape and the target position is or are achieved as far as possible. 
     
     
         5 . The coating device according to  claim 1 , wherein a number of magnets per wide side is uneven.