Processing line for the continuous processing of metal strips having a dual purpose of producing strips that are annealed and dip-coated or not coated, and corresponding cooling tower and method for switching from one configuration to the other

Abstract

Disclosed is a treatment line for the continuous treatment of metal strips having a dual purpose, i.e. for producing strips that are annealed and dip-coated with a metal alloy and for producing strips that are annealed and not coated, comprising a dual-purpose cooling tower, i.e. for cooling strips that are annealed and not coated in a non-oxidizing atmosphere and for air-cooling strips that are annealed and coated.

1 . Cooling tower for a continuous treatment line for metal strips having a dual purpose, which has a configuration for producing strips that are annealed and dip-coated and a configuration for producing strips that are annealed and not coated, characterized in that it is intended to operate in both line configurations and it comprises blowing means for cooling the strip selectively under a non-oxidizing atmosphere in the configuration for uncoated annealed strips and under air in the configuration for annealed and coated strips. 
     
     
         2 . Cooling tower according to  claim 1 , further comprising cooling sections connected together to form a sealed cooling tunnel. 
     
     
         3 . Cooling tower according to  claim 2 , wherein the sealed cooling tunnel is further formed by connecting tunnels interposed between two cooling sections and/or other elements. 
     
     
         4 . Cooling tower according to  claim 2 , wherein the sealed tunnel extends only over a rising strand. 
     
     
         5 . Cooling tower according to  claim 2 , wherein the sealed tunnel extends over a rising strand and a descending strand. 
     
     
         6 . Cooling tower according to  claim 1 , further comprising, in the direction of travel of the strip, in the configuration for producing uncoated annealed strips, means for sampling a non-oxidizing atmosphere present at the strip upstream of the blowing means, means for recirculating and cooling said sampled atmosphere, the blowing means being arranged to blow the sampled, cooled and recirculated atmosphere. 
     
     
         7 . Method for switching from one configuration to another of a cooling tower according to  claim 1 , characterized in that it comprises the following steps:
 for switching to the configuration for producing strips that are annealed and not dip-coated with a metal alloy, connecting the blowing means to a non-oxidizing atmosphere,   for switching to the configuration for producing annealed and coated strips: connecting the blowing means to air.   
     
     
         8 . Cooling tower for a continuous treatment line for metal strips having a dual purpose, which has a configuration for producing strips that are annealed and dip-coated and a configuration for producing strips that are annealed and not coated, comprising a cooling tower according to  claim 1 . 
     
     
         9 . Line according to  claim 8 , comprising, successively in the direction of travel of the strip, an immersion tunnel, a bath area provided with equipment in said configuration for producing strips that are annealed and dip-coated in a metal alloy, wherein the bath area is removable and can be replaced by a box designed to provide a sealed fluid connection between the immersion tunnel and the cooling tower. 
     
     
         10 . Line according to  claim 8 , not comprising a final cooling section. 
     
     
         11 . Method for switching from one configuration to another of a treatment line for the continuous treatment of metal strips having a dual purpose according to  claim 8 , comprising the steps of the method for switching from said configuration to said other configuration of a cooling tower according to  claim 7  and further comprising the following steps:
 to switch to the configuration for producing annealed strips not dip-coated in a metal alloy:
 removing equipment from the bath area, and 
 replacing said equipment with the box, 
 
 to switch to the configuration for producing annealed strip dip-coated with a metal alloy:
 removing the box, and 
 replacing with the equipment of the bath area.