Process and device for surface treatment of strips with liquids

Abstract

A device for surface treatment of continuously moving strip, particularly for pickling rolled metal strip, includes a trough-shaped tank containing a treating liquid bath. The trough includes a panel mounted therein and submerged in the liquid, and aligned approximately parallel to the strip. The panel divides the treatment bath into a treatment area underneath the panel through which the strip being treated passes and a return flow sector for the liquid above the panel. The treating liquid is collected in the return flow sector at a discharge end of the trough and is directed along the return flow sector to a receiving end of the trough.

What is claimed is:  
     
       1. An apparatus for immersing a strip material in a liquid bath, the apparatus comprising: 
       a trough having a longitudinal dimension with a bottom wall, first and second side walls, a strip material receiving end and a strip material discharge end, said trough being dimensioned to receive a treating liquid and contain a liquid bath; and  
       at least one panel mounted within said trough and submerged in the liquid bath, said at least one panel having a bottom surface spaced from said bottom wall of said trough for defining a contact zone between said panel and bottom wall of said trough and extending substantially the length of said trough, said at least one panel further having a top surface defining a return zone for receiving liquid from said discharge end of said trough and directing said liquid along said top surface from said discharge end to said receiving end of said trough;  
       wherein said at least one panel extends substantially a length of said trough from said receiving end to said discharge end, and extends from said first side wall to said second side wall to separate said contact zone from said return zone.  
     
     
       2. The apparatus of  claim 1 , further comprising 
       a strip material feed device for feeding a strip material to said trough and for conveying said strip material from said receiving end through said contact zone to said discharge end of said trough.  
     
     
       3. The apparatus of  claim 1 , further comprising 
       a cover enclosing said trough.  
     
     
       4. The apparatus of  claim 3 , wherein said 
       cover is coupled to said at least one panel whereby said at least one panel is raised by raising said cover.  
     
     
       5. The apparatus of  claim 1 , wherein said at least one panel is substantially parallel to a direction of travel of the strip material through said contact zone. 
     
     
       6. The apparatus of  claim 1 , wherein said at least one panel contacts said first and second side walls to prevent liquid from passing between said at least one panel and said first and second side walls. 
     
     
       7. The apparatus of  claim 1 , wherein said 
       at least one panel includes a plurality of holes therein for forming liquid passages between said contact zone and said return zone.  
     
     
       8. The apparatus of  claim 1 , 
       wherein said at least one panel has a substantially V-shaped cross-section.  
     
     
       9. The apparatus of  claim 1 , further comprising 
       a plurality of spaced-apart fins extending from said at least one panel into said contact zone.  
     
     
       10. The apparatus of  claim 9 , wherein said fins extend substantially perpendicular to said at least one panel, and are disposed substantially transverse to said longitudinal dimension of said trough. 
     
     
       11. The apparatus of  claim 1 , further comprising 
       a plurality of fluid inlets disposed in said side walls of said trough for directing treating liquid into said contact zone.  
     
     
       12. The apparatus of  claim 11 , further comprising 
       at least one fluid inlet disposed in said bottom wall of said trough for directing treating liquid into said contact zone.  
     
     
       13. The apparatus of  claim 1 , further comprising 
       at least one fluid inlet in said trough for directing treating liquid into said contact zone in a direction against an advancing direction of said strip material at an angle with respect to said longitudinal dimension of said trough.  
     
     
       14. The apparatus of  claim 1 , wherein said at least one panel is movable away from said contact zone by contact with said strip material. 
     
     
       15. The apparatus of  claim 14 , further comprising 
       a cover for closing said trough, and wherein said at least one panel is coupled to and supported by said cover.  
     
     
       16. An apparatus for immersing a strip material in a liquid bath, the apparatus comprising: 
       a trough having a longitudinal dimension with a bottom wall, first and second side walls, a strip material receiving end and a strip material discharge end, said trough being dimensioned to receive a treating liquid and contain a liquid bath;  
       a plurality of panels mounted within said trough and submerged in the liquid bath, said at least one panel having a bottom surface spaced from said bottom wall of said trough for defining a contact zone in said trough, said at least one panel further having a top surface defining a return zone for receiving liquid from said discharge end of said trough and directing said liquid along said top surface from said discharge end to said receiving end of said trough; and  
       said panels being spaced apart along a length of said trough and being spaced apart a distance to define a liquid passage between said contact zone and said return zone.  
     
     
       17. An apparatus for immersing a strip material in a liquid bath, the apparatus comprising: 
       a trough containing a liquid bath, said trough having a longitudinal dimension, first and second side walls, a bottom wall, and a first end wall at a strip material receiving end and a second end wall at a discharge end for said strip material;  
       a divider positioned in said trough extending substantially parallel to said bottom wall and defining a contact zone in a bottom section of said trough and a liquid return zone in an upper section of said trough for directing liquid from said discharge end to said receiving end of said trough, wherein said divider extends from said first side wall to said second side wall to separate said contact zone from said return zone; and  
       a feed device for feeding strip material from said receiving end to said discharge end through said contact zone.  
     
     
       18. The apparatus of  claim 17 , wherein said 
       divider includes a plurality of holes therein for forming a liquid passage between said contact zone and said return zone.  
     
     
       19. The apparatus of  claim 17 , 
       wherein said divider has a substantially V-shaped cross-section.  
     
     
       20. The apparatus of  claim 17 , further comprising 
       a plurality of spaced-apart fins extending substantially perpendicular to said divider, and disposed substantially transverse to said longitudinal dimension of said trough.  
     
     
       21. The apparatus of  claim 17 , further comprising 
       a plurality of fluid inlets disposed in said side walls of said trough for directing treating liquid into said contact zone.  
     
     
       22. The apparatus of  claim 21 , further comprising 
       at least one fluid inlet disposed in said bottom wall of said trough for directing treating liquid substantially upward into said contact zone.  
     
     
       23. The apparatus of  claim 17 , further comprising 
       at least one fluid inlet in said trough for directing treating liquid into said contact zone in a direction against an advancing direction of said strip material and at an angle with respect to said longitudinal dimension of said trough.  
     
     
       24. The apparatus of  claim 17 , further comprising a cover for enclosing said trough and being coupled to said divider, wherein said divider is movable away from said contact zone by contact with said strip material. 
     
     
       25. An apparatus for immersing a strip material in a liquid bath, said apparatus comprising: 
       a trough containing a liquid bath and having a longitudinal dimension, first and second side walls, a bottom wall, and a first end wall at a strip material receiving end and a second end wall at a discharge end for said strip material;  
       a divider comprising a plurality of panels positioned in said trough defining a contact zone and a liquid return zone for directing liquid from said discharge end to said receiving end of said trough, wherein said panels are substantially parallel to said bottom wall;  
       said panels being spaced apart along said longitudinal dimension of said trough and being spaced apart a distance to define a liquid passage between said treating zone and said return zone; and  
       a feed device for feeding strip material from said receiving end to said discharge end through said contact zone.  
     
     
       26. A process for contacting a strip material with a liquid bath, comprising the steps of 
       feeding a strip material to a receiving end of a trough and directing said strip material to a discharge end of the trough, wherein said trough contains a liquid bath between said receiving and discharge ends, said trough including a divider extending from said receiving end to said discharge end and contacting opposite side walls of said trough for preventing liquid from passing between said divider and side walls for defining a strip material contact zone in a bottom section of said trough and a liquid return zone in a top section of said trough;  
       conveying said strip material through said contact zone and creating a current of said liquid through said contacting zone from said receiving end to said discharge end of said trough;  
       directing said current of liquid at said discharge end to said return zone and returning said liquid to said receiving end of said trough; and  
       discharging said material strip from said discharge end of said trough.  
     
     
       27. The process of  claim 26 , further comprising 
       injecting a liquid into said contacting zone in a direction counter to an advancing direction of said strip material.  
     
     
       28. The process of  claim 26 , further comprising 
       injecting a liquid into said contact zone in a substantially upward direction toward said strip material.  
     
     
       29. The process of  claim 26 , wherein said divider includes a plurality of holes and said process comprises transferring liquid between said return zone and said contact zone. 
     
     
       30. The process of  claim 26 , wherein said strip material is a metal strip and said liquid is a pickling bath, and said process comprises pickling said metal strip. 
     
     
       31. The process of  claim 26 , comprising 
       providing a plurality of holes in said divider and forming a liquid passage between said contacting zone and said return zone.  
     
     
       32. The process of  claim 26 , wherein said divider has a substantially V-shaped cross-section. 
     
     
       33. The process of  claim 26 , further comprising 
       providing a plurality of spaced-apart fins extending substantially perpendicular from said divider, and disposed substantially transverse to said longitudinal dimension of said trough.  
     
     
       34. A process for contacting a strip material with a liquid bath comprising the steps of 
       feeding a strip material to a receiving end of a trough and directing said strip material to a discharge end of said trough, wherein said trough contains a liquid bath between said receiving and discharge ends, said trough including a divider defining a strip material contact zone in a bottom section of said trough and a liquid return zone in a top section of said trough;  
       wherein said divider comprises a plurality of panels spaced apart along a length of said trough, said panels being spaced apart a distance to define a liquid passage between said contacting zone and said return zone;  
       conveying said strip material through said contact zone and creating a current of said liquid through said contacting zone from said receiving end to said discharge end;  
       directing said current of liquid at said discharge end to said return zone and returning said liquid to said receiving end; and  
       discharging said material strip from said discharge end of said trough.  
     
     
       35. An apparatus for immersing a strip material in a liquid bath, the apparatus comprising: 
       
         a trough containing a liquid bath, said trough having a longitudinal dimension, first and second side walls, a bottom wall, and a first end wall at a strip material receiving end and a second end wall at a discharge end for said strip material;  
       
         a divider positioned in said trough extending substantially parallel to said bottom wall and defining a contact zone in a bottom section of said trough and a liquid return zone in an upper section of said trough for directing liquid from said discharge end toward said receiving end of said trough in a substantially unidirectional flow, wherein said divider comprises a plurality of spaced - apart panels, said divider extending between said receiving end and said discharge end and extending from said first side wall to said second side wall to separate said contact zone from said return zone; and    
       
         a feed device for feeding strip material from said receiving end to said discharge end through said contact zone. 
       
     
     
       36. The apparatus of  claim 35 , wherein said divider is substantially solid without holes. 
     
     
       37. An apparatus for contacting a strip material in a liquid bath, the apparatus comprising: 
       
         a trough having a longitudinal dimension with a bottom wall and first and second side walls, a receiving end and a discharge end, said trough being dimensioned to receive a treating liquid and contain a liquid bath;  
       
       
         a strip material conveying device for conveying a strip through said trough,  
       
         a plurality of spaced - apart panels extending substantially from said receiving end to said discharge end of said trough, each of said panels mounted within said trough and submerged in the liquid bath, each of said panels having a top surface, a bottom surface, a receiving end and a discharge end, said bottom surface being spaced from said bottom wall of said trough for defining a contact zone in said trough and directing said liquid in a substantially unidirectional flow from a receiving end of said contact zone to a discharge end of said contact zone by movement of said strip though said contact zone, said top surface of said panel defining a return zone for receiving liquid from said discharge end of said contact zone and directing said liquid along said top surface from said discharge end in a substantially unidirectional flow to said receiving end of said contact zone; and    
       
         said panels being spaced apart a distance to define a gap which allows liquid to flow from said contact zone through said gap into said return zone above said panel, and as a result of fluid pressure said liquid flows back towards said receiving end of said trough. 
       
     
     
       38. The apparatus of  claim 37 , further comprising a cover for closing said trough, wherein said panels are coupled to and suspended by said cover. 
     
     
       39. The apparatus of  claim 37 , wherein said panels are solid panels without openings. 
     
     
       40. The apparatus of  claim 37 , wherein said panels extend between said side walls of said trough to separate said contact zone from said return zone. 
     
     
       41. The apparatus of  claim 37 , wherein said discharge end of said panels is substantially parallel to said receiving end of an adjacent panel. 
     
     
       42. A process for contacting a strip material with a liquid bath comprising the steps of 
       
         feeding a strip material to a receiving end of said liquid bath in a trough and directing said strip material to a discharge end of said liquid bath, wherein said bath includes a plurality of panels spaced apart along a length of said liquid bath substantially from said receiving end to said discharge end, each of said panels having a top surface, a bottom surface, a receiving end and a discharge end, each said panel forming a contact zone below said panel and a return zone above said panel, said panels being spaced apart a distance to define a gap between adjacent panels;  
       
       
         conveying said strip material through said contact zone and creating a substantially unidirectional flow of said liquid through said contact zone from said receiving end to said discharge end of each of said panels, and directing at least a portion of liquid at said discharge end of said contact zone through said gap to said return zone and directing said liquid back in a substantially unidirectional flow toward said receiving end of said panel; and  
       
       
         discharging said material strip from said downstream end of said liquid bath. 
       
     
     
       43. The process of  claim 42 , wherein each of said panels are solid panels without openings. 
     
     
       44. The process of  claim 42 , wherein said panels extend between said side walls of said trough for preventing liquid from passing between said panels and said side walls between said contact zone and said return zone. 
     
     
       45. An apparatus for contacting a strip material in a liquid bath, the apparatus comprising: 
       
         a trough having an open top end with first and second side walls, and a bottom wall, said trough containing a liquid bath for contacting a strip material;  
       
       
         a cover member for closing said open top end of said trough;  
       
         a plurality of panels coupled to and suspended by said cover, each said panels being positioned in said liquid bath spaced from said bottom wall and defining a contact zone between each of said panels and said bottom wall of said trough, each of said panels having a receiving end defining a receiving end of said contact zone and a discharge end defining a discharge end of said contact zone, each of said panels further defining a liquid return zone above a respective panel for directing liquid from said discharge end of said panel to said receiving end of said panel, wherein said panels extend between said first side wall and said second side wall to separate said contact zone from said return zone, said panels being spaced - apart a distance to define a gap therebetween; and    
       
         a feed device for feeding a strip material from said receiving end to said discharge end through each of said contact zones thereby producing a substantially unidirectional flow of liquid through said contact zone from said receiving end of each of said panels to said discharge end of each of said panels, and producing a substantially unidirectional flow of said liquid from said discharge end of each of said panels through said return zone to said receiving end of said panels, said feed device further producing a fluid pressure in said contact zone to direct a flow of liquid through said gap to said return zone and back towards said receiving end of each of said panels. 
       
     
     
       46. The apparatus of  claim 45 , wherein said panels are spaced apart along a length of said trough between a receiving end of said trough and a discharge end of said trough.