Machine for the production of a fiber web

Abstract

The current invention relates to a machine for the production of a fiber web, specifically a paper or cardboard web, from at least one fiber stock suspension comprising at least one porous belt, specifically a wire belt, a felt belt, or similar belt, running continuously in the direction of web travel. Further including at least one suction box, including a closed box that can be connected to a vacuum source. On its upper surface that is in contact with the belt, a multitude of cover strips are mounted at certain distances from each other and vertical to the direction of travel L of the belt, forming suction slots. At least one suction box cover strip at which a pressure differential exists due to various prevailing ambient pressures, and has a width making contact with the wire, viewed vertically to the direction of travel of the belt, and having a value factor a* of the average width of the cover strips that are contacting the wire, whereby the value factor takes on a numerical value in the range of 0.05 to 0.95, preferably of 0.1 to 0.9 and whereby the average wire-contacting width of the cover strips is in the range of 10 mm to 30 mm.

What is claimed is:  
     
         1 . A machine for the production of a fiber web from at least one fiber stock suspension, comprising: 
 at least one porous belt movable in a direction of travel;    at least one suction box including a closed box connected to a vacuum source and an upper surface proximate to said belt, said suction box including a plurality of adjacent cover strips on said upper surface defining a plurality of suction slots therebetween, each said cover strip having a height orthogonal to a direction of travel of said belt, each said cover strip having an atmospheric side at prevailing ambient pressure and a vacuum side at prevailing vacuum pressure of said vacuum source thereby creating a pressure differential between said atmospheric side and said vacuum side, said belt side having a wire-contacting width being said direction of travel, at least one said wire-contacting width being between approximately 10 mm to 30 mm, and a value factor associated with at least one said wire-contacting width between approximately 0.05 to 0.95.    
     
     
         2 . The machine of  claim 1 , wherein said value factor is between approximately 0.1 to 0.9.  
     
     
         3 . The machine of  claim 1 , wherein a single said cover strip has said wire-contacting width between approximately 10 mm to 30 mm, and a value factor associated with said wire-contacting width between approximately 0.05 to 0.95, said single cover strip being a last cover strip as viewed in said direction of travel.  
     
     
         4 . The machine of  claim 1 , wherein one of said cover strip has said wire-contacting width between approximately 10 mm to 30 mm, and a value factor associated with said wire-contacting width between approximately 0.05 to 0.95, said one cover strip being a first cover strip as viewed in said direction of travel.  
     
     
         5 . The machine of  claim 1 , wherein each said cover strip has a form, a majority of said plurality of cover strips having a same form.  
     
     
         6 . The machine of  claim 1 , wherein at least one said cover strip has a contour of horizontal plane form, facing said belt.  
     
     
         7 . The machine of  claim 6 , wherein said contour has at least one of an ascending radius and a descending radius, both said ascending radius and said descending radius having a value between approximately 1 mm to 10 mm.  
     
     
         8 . The machine of  claim 7 , wherein both said ascending radius and said descending radius are between approximately 2.5 mm to 7.5 mm.  
     
     
         9 . The machine of  claim 1 , wherein at least one said cover strip has a contour facing said belt of one of stable curved, arched, parabolic and polygon.  
     
     
         10 . The machine of  claim 9 , wherein said contour is located in one of said central position and off-center position.  
     
     
         11 . The machine of  claim 9 , wherein said off-center position is offset in said direction of travel.  
     
     
         12 . The machine of  claim 9 , wherein at least one said cover strip also has a meander shape as viewed vertical to said direction of travel.  
     
     
         13 . The machine of  claim 9 , wherein at least one said cover strip having a contour includes at least one reinforcing rib in contact with said belt.  
     
     
         14 . The machine of  claim 13 , wherein at least one said reinforcing rib has a width in said direction of travel of between approximately 1 mm to 15 mm, at least one said reinforcing rib includes at least one of an ascending radius and a descending radius, both said ascending radius and said descending radius being between approximately 0.5 mm to 10 mm.  
     
     
         15 . The machine of  claim 14 , wherein said width is between approximately 2 mm to 12 mm.  
     
     
         16 . The machine of  claim 14 , wherein both said ascending radius and said descending radius are between approximately 1 mm to 7.5 mm.  
     
     
         17 . The machine of  claim 13 , wherein said reinforcing strips are positioned at approximately uniform distances as viewed in said direction of travel across preferably an entire length of at least one said cover strip.  
     
     
         18 . The machine of  claim 13 , wherein at least one said cover strip has a center area and two edge areas bounding said center area, at least one said reinforcing rib being positioned at an approximately uniform first distance in said direction of travel in said center area and an approximately uniform second distance in said direction of travel in said edge areas, said uniform second distance smaller than said uniform first distance.  
     
     
         19 . The machine of  claim 13 , wherein at least one said cover strip has two edge areas, said at least one reinforcing ribs are positioned an approximately uniform distance in said direction of travel in said edge areas.  
     
     
         20 . The machine of  claim 13 , wherein at least one said cover strip includes a basic body located a distance orthogonal to said direction of travel from said belt of between approximately 2 mm to 20 mm.  
     
     
         21 . The machine of  claim 20 , wherein said orthogonal distance is between approximately 5 mm to 15 mm.  
     
     
         22 . The machine of  claim 1 , wherein said belt is a wire in one of a twin wire former, an endless wire former and a hybrid former.  
     
     
         23 . The machine of  claim 1 , wherein said belt is a felt in a press section.  
     
     
         24 . The machine of  claim 1 , wherein at least one said suction box is part of one of a forming suction box, a wet suction box and a HiVac box of a twin wire former.  
     
     
         25 . The machine of  claim 1 , wherein at least one said suction box is part of one of a wet suction box, a flat suction box and a HiVac box in one of an endless wire former and a hybrid former.  
     
     
         26 . The machine of  claim 1 , wherein at least one said suction box is a component for intermediate conditioning of press felts that are running in a tandem configuration.  
     
     
         27 . A machine for the production of a fiber web from at least one fiber stock suspension, comprising: 
 at least one porous belt movable in a direction of travel;    at least one suction couch roll connected to a vacuum source and including a surface proximate to said belt; and    at least one cover strip on said surface, each said cover strip having a height vertical to a direction of travel of said belt, each said cover strip having an atmospheric side at prevailing ambient pressure and a vacuum side at prevailing vacuum pressure of said vacuum source thereby creating a pressure differential between said atmospheric side and said vacuum side, said belt side having a wire-contacting width in said direction of travel, at least one said wire-contacting width being between approximately 10 mm to 30 mm, and a value factor associated with at least one said wire-contacting width is between approximately 0.05 to 0.95.