Press arrangement

Abstract

Press arrangement for dewatering a paper, board, tissue or other fibrous web in a machine for producing and/or finishing the same. Arrangement includes only one elongated dewatering nip, through which the fibrous web, having at least one endlessly circulating water-absorbing dewatering belt arranged on each web surface, is led. After the dewatering nip, the fibrous web runs through a smoothing nip. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

1 . A press arrangement for dewatering a paper, board, tissue or other fibrous web in a machine for producing and/or finishing the same, having only one dewatering nip, which is of extended design and through which, in addition to the fibrous web, on both sides in each case at least one endlessly circulating water-absorbing dewatering belt is led, wherein the fibrous web runs through a smoothing nip after the dewatering nip.  
   
   
       2 . The press arrangement as claimed in  claim 1 , wherein the dewatering nip is formed by a shoe press roll having a flexible roll shell, which is pressed against a cylindrical mating roll by a pressing element with a concave press surface.  
   
   
       3 . The press arrangement as claimed in  claim 1 , wherein the press nip is at least 300 mm, preferably at least 350 mm, long in the web running direction.  
   
   
       4 . The press arrangement as claimed in  claim 1 , wherein the dewatering belts are at least 25 m long.  
   
   
       5 . The press arrangement as claimed in  claim 1 , wherein the dewatering belt running under the fibrous web, after discharging the fibrous web, wraps around at least one deflection guide roll located in the loop of this dewatering belt, after which the fibrous web runs onward counter to the web running direction.  
   
   
       6 . The press arrangement as claimed in  claim 5 , wherein the lower dewatering belt, after the deflection guide roll, wraps around an outer guide roll located outside the loop of this dewatering belt.  
   
   
       7 . The press arrangement as claimed in  claim 6 , wherein the outer guide roll is assigned a doctor.  
   
   
       8 . The press arrangement as claimed in  claim 1 , wherein the fibrous web, after being led away from the dewatering belts, runs unsupported over a free section as far as the smoothing nip.  
   
   
       9 . The press arrangement as claimed in  claim 8 , wherein a knock-off device severing the fibrous web as required is arranged in the region of the free section.  
   
   
       10 . The press arrangement as claimed in  claim 1 , wherein the smoothing nip is formed by two smoothing rolls and the lower smoothing roll of the smoothing nip can preferably be moved vertically.  
   
   
       11 . The press arrangement as claimed in  claim 1 , wherein, after the smoothing nip, the fibrous web is led to at least one following drying group, in which the fibrous web preferably comes into contact with heated drying cylinders for the purpose of drying and is supported by at least one dryer fabric.  
   
   
       12 . The press arrangement as claimed in  claim 11 , wherein the fibrous web is dried on two sides in the drying group.  
   
   
       13 . The press arrangement as claimed in  claim 11 , wherein the fibrous web is dried on one side in the drying group.  
   
   
       14 . The press arrangement as claimed in  claim 11 , wherein the fibrous web runs unsupported between the smoothing nip and the pick-up by the dryer fabric.  
   
   
       15 . The press arrangement as claimed in  claim 1 , wherein at least one smooth, endlessly circulating transfer belt is led through the smoothing nip.  
   
   
       16 . The press arrangement as claimed in  claim 15 , when the transfer belt transfers the fibrous web to the dryer fabric.  
   
   
       17 . The press arrangement as claimed in  claim 11 , wherein there is a pulper under the press arrangement and the start of the first drying group.  
   
   
       18 . The press arrangement as claimed in  claim 1 , wherein the fibrous web is led through a coating apparatus after the drying.