Headbox for a machine for producing a fibrous material web, in particular a paper or cardboard web

Abstract

A headbox for a machine for producing a fibrous material web, in particular a paper or cardboard web, includes: a central assembly preferably forming the carrier elements of a turbulence generator, said assembly having a table leaf on the bottom side; and a headbox nozzle adjoining directly downstream in the machine running direction and extending in the machine transverse direction, said nozzle comprising at least one lower and one upper continuous nozzle wall extending over the machine width. The lower nozzle wall of the headbox nozzle of the headbox includes a lower lip plate, in particular a lower lip carrier plate, which is connected, in particular welded, to the table leaf of the central assembly by means of ribs extending in the machine running direction and spaced apart in the machine transverse direction. The ribs are designed in an elastic or pliable manner in the machine transverse direction.

What is claimed is: 
     
         1 . A headbox for a machine for producing a web of fibrous material, the web being one of a paper web and a cardboard web, said headbox comprising:
 a central assembly including a bottom side and having a table leaf on said bottom side;   a plurality of ribs; and   a headbox nozzle adjoining said central assembly directly downstream in a machine direction and extending in a cross machine direction, said headbox nozzle including at least one continuous lower nozzle wall and at least one continuous upper nozzle wall extending across a machine width, said at least one continuous lower nozzle wall of said headbox nozzle including a lower lip plate which is connected to said table leaf of said central assembly by way of said plurality of ribs extending in said machine direction and spaced apart in said cross machine direction, said plurality of ribs being one of pliable and flexible in said cross machine direction.   
     
     
         2 . The headbox according to  claim 1 , further including a turbulence generator, said central assembly forming a plurality of carrier elements of said turbulence generator. 
     
     
         3 . The headbox according to  claim 1 , wherein said lower lip plate is welded to said table leaf. 
     
     
         4 . The headbox according to  claim 1 , wherein said lower lip plate is a lower lip support plate. 
     
     
         5 . The headbox according to  claim 4 , wherein said lower lip support plate of said at least one continuous lower nozzle wall of said headbox nozzle includes an upper and outlet side, said lower lip support plate being equipped on said upper and outlet side with a lower lip. 
     
     
         6 . The headbox according to  claim 5 , wherein said lower lip is positionable. 
     
     
         7 . The headbox according to  claim 1 , wherein individual ones of said plurality of ribs extend at least partially generally vertically and thereby perpendicular to said at least one continuous lower nozzle wall of said headbox nozzle and said table leaf of said central assembly. 
     
     
         8 . The headbox according to  claim 1 , wherein individual ones of said plurality of ribs have a rib thickness in a range of 10 mm to 75 mm. 
     
     
         9 . The headbox according to  claim 1 , wherein individual ones of said plurality of ribs have a rib thickness in a range of 15 mm to 60 mm. 
     
     
         10 . The headbox according to  claim 1 , wherein individual ones of said plurality of ribs have a rib thickness in a range of 20 mm to 50 mm. 
     
     
         11 . The headbox according to  claim 1 , wherein individual ones of said plurality of ribs have a rib separation in a range of 100 mm to 500 mm. 
     
     
         12 . The headbox according to  claim 1 , wherein individual ones of said plurality of ribs have a rib separation in a range of 125 mm to 400 mm. 
     
     
         13 . The headbox according to  claim 1 , wherein individual ones of said plurality of ribs have a rib separation in a range of 150 mm to 250 mm. 
     
     
         14 . The headbox according to  claim 1 , wherein said table leaf of said central assembly includes a first region facing said lower lip plate, said table leaf in said first region facing said lower lip plate including a first chamfer forming a first bevel, said first chamfer having a first length of at least 25 mm. 
     
     
         15 . The headbox according to  claim 14 , wherein said lower lip plate is a lower lip support plate. 
     
     
         16 . The headbox according to  claim 14 , wherein said first length is at least 40 mm. 
     
     
         17 . The headbox according to  claim 14 , wherein said first length is at least 50 mm. 
     
     
         18 . The headbox according to  claim 14 , wherein said lower lip plate includes a second region facing said table leaf of said central assembly, said lower lip plate including a second chamfer forming a second bevel in said second region facing said table leaf of said central assembly, said second chamfer having a second length of at least 25 mm. 
     
     
         19 . The headbox according to  claim 18 , wherein said lower lip plate is a lower lip support plate. 
     
     
         20 . The headbox according to  claim 18 , wherein said second length is at least 40 mm. 
     
     
         21 . The headbox according to  claim 18 , wherein said second length is at least 50 mm. 
     
     
         22 . The headbox according to  claim 18 , wherein said first bevel and said second bevel formed respectively by said first chamfer and said second chamfer encompass together an angle of 0 to 45°. 
     
     
         23 . The headbox according to  claim 22 , wherein said angle is 5 to 30°. 
     
     
         24 . The headbox according to  claim 22 , wherein said angle is 10 to 20°. 
     
     
         25 . The headbox according to  claim 22 , wherein individual ones of said plurality of ribs which connect said lower lip plate with said table leaf of said central assembly are structured to fill in in said first region and said second region respectively of said first chamfer and said second chamfer. 
     
     
         26 . The headbox according to  claim 25 , wherein said lower lip plate is a lower lip support plate. 
     
     
         27 . The headbox according to  claim 1 , wherein said table leaf of said central assembly and said lower lip plate have a perpendicular distance in a first range of 10 mm to 100 mm, said perpendicular distance being measured between a theoretic inside extension of said table leaf of said central assembly and a theoretic corner edge of said lower lip plate. 
     
     
         28 . The headbox according to  claim 27 , wherein said lower lip plate is a lower lip support plate. 
     
     
         29 . The headbox according to  claim 27 , wherein said first range is 20 mm to 80 mm. 
     
     
         30 . The headbox according to  claim 27 , wherein said first range is 25 mm to 65 mm. 
     
     
         31 . The headbox according to  claim 27 , wherein a minimum height of individual ones of said plurality of ribs between said table leaf of said central assembly and said lower lip plate assumes a value in a second range of 1.5 to 4 times said perpendicular distance between said table leaf of said central assembly and said lower lip plate. 
     
     
         32 . The headbox according to  claim 31 , wherein said lower lip plate is a lower lip support plate. 
     
     
         33 . The headbox according to  claim 31 , wherein said second range is 2 to 3 times said perpendicular distance between said table leaf of said central assembly and said lower lip plate. 
     
     
         34 . The headbox according to  claim 1 , wherein said table leaf includes a front side, individual ones of said plurality of ribs including a region facing said front side of said table leaf and a compensating gap in said region facing said front side of said table leaf, each respective said compensating gap having a height in a range of 2 mm to 15 mm. 
     
     
         35 . The headbox according to  claim 34 , wherein said range is 3 mm to 12 mm. 
     
     
         36 . The headbox according to  claim 34 , wherein said range is 5 mm to 10 mm. 
     
     
         37 . The headbox according to  claim 1 , wherein a plurality of joints at least one of (a) between said table leaf of said central assembly and respectively individual ones of said plurality of ribs and (b) between said lower lip plate and respectively said individual ones of said plurality of ribs which are formed as a plurality of welding seams have a welding seam thickness in a range of 3 to 15 mm. 
     
     
         38 . The headbox according to  claim 37 , wherein said lower lip plate is a lower lip support plate. 
     
     
         39 . The headbox according to  claim 37 , wherein said range is 4 mm to 12 mm. 
     
     
         40 . The headbox according to  claim 37 , wherein said range is 5 mm to 10 mm. 
     
     
         41 . The headbox according to  claim 1 , wherein individual ones of said plurality of ribs respectively are connected one of directly and indirectly by at least one hinged joint and at least one of a base plate and a pedestal with a bed plate. 
     
     
         42 . A machine to produce a web of fibrous material from at least one fibrous stock suspension, the web being one of a paper web, a cardboard web, and a tissue web, said machine comprising:
 at least one headbox including:
 a central assembly including a bottom side and having a table leaf on said bottom side; 
 a plurality of ribs; and 
 a headbox nozzle adjoining said central assembly directly downstream in a machine direction and extending in a cross machine direction, said headbox nozzle including at least one continuous lower nozzle wall and at least one continuous upper nozzle wall extending across a machine width, said at least one continuous lower nozzle wall of said headbox nozzle including a lower lip plate which is connected to said table leaf of said central assembly by way of said plurality of ribs extending in said machine direction and spaced apart in said cross machine direction, said plurality of ribs being one of pliable and flexible in said cross machine direction. 
   
     
     
         43 . The machine according to  claim 42 , further including a turbulence generator, said central assembly forming a plurality of carrier elements of said turbulence generator. 
     
     
         44 . The machine according to  claim 42 , wherein said lower lip plate is welded to said table leaf. 
     
     
         45 . The machine according to  claim 42 , wherein said lower lip plate is a lower lip support plate.