Conditioning and/or cleaning device

Abstract

Device for conditioning, cleaning, and/or keeping clean at least one of a rotating roll and a circulating belt of a paper machine. The device includes at least two doctors arranged behind one another in a roll and/or belt travel direction and spaced at a distance from one another. The at least two doctors are assigned to the at least one of the rotating roll and the circulating belt.

What is claimed:  
     
         1 . A device for conditioning, cleaning, and/or keeping clean at least one of a rotating roll and a circulating belt of a paper machine, comprising: 
 at least two doctors arranged behind one another in a roll and/or belt travel direction and spaced at a distance from one another, wherein said at least two doctors are assigned to the at least one of the rotating roll and the circulating belt.    
     
     
         2 . The device in accordance with  claim 1 , wherein said at least two doctors are located before a take-on point at which at least one felt is guided onto the at least one of the roll and the belt.  
     
     
         3 . The device in accordance with  claim 2 , further comprising a boundary layer doctor positioned adjacent said at least one felt before the take-on point, 
 wherein a rear doctor of said at least two doctors, when viewed in the travel direction, is connected to said boundary layer doctor.    
     
     
         4 . The device in accordance with  claim 3 , further comprising a low-pressure suction device arranged for suctioning a wedge-shaped opening formed at least by the at least one of the roll and the belt, said at least one felt, said rear doctor, and said boundary layer doctor.  
     
     
         5 . The device in accordance with  claim 3 , wherein a distance between said boundary layer doctor and the take-on point is less that approximately 500 mm.  
     
     
         6 . The device in accordance with  claim 5 , wherein said distance is less than about 400 mm.  
     
     
         7 . The device in accordance with  claim 5 , wherein said distance is less than approximately 300 mm.  
     
     
         8 . The device in accordance with  claim 1 , further comprising: 
 a press arranged before the at least one of the roll and the belt; and    a low pressure suction device arranged for suctioning a space between said press and the at least one of the roll and the belt.    
     
     
         9 . The device in accordance with  claim 1 , wherein the at least one of the roll and the belt comprises a suction felt guidance roll.  
     
     
         10 . The device in accordance with  claim 9 , further comprising a first press of a pressing section of a paper machine, wherein said suction felt guidance roll is provided subsequently to said first press.  
     
     
         11 . The device in accordance with  claim 10 , wherein said first press comprises a roll press.  
     
     
         12 . The device in accordance with  claim 10 , wherein said first press comprises an extended nip press.  
     
     
         13 . The device in accordance with  claim 10 , further comprising a spray guard positioned between said suction felt guidance roll and said first press.  
     
     
         14 . The device in accordance with  claim 13 , wherein said spray guard is arranged to extend substantially across a width of the machine.  
     
     
         15 . The device in accordance with  claim 1 , further comprising at least one cleaning device acting on a surface of the at least one of the roll and the belt.  
     
     
         16 . The device in accordance with  claim 15 , wherein said at least one cleaning device is positioned between said at least two doctors.  
     
     
         17 . The device in accordance with  claim 15 , wherein said at least one cleaning device comprises at least one jet cleaning or spray device arranged to direct a pressurized medium at said surface.  
     
     
         18 . The device in accordance with  claim 17 , wherein said pressurized medium comprises a fluid or air.  
     
     
         19 . The device in accordance with  claim 18 , wherein said fluid comprises water.  
     
     
         20 . The device in accordance with  claim 15 , wherein said at least one cleaning device comprises a combined blowing or spraying device and suction device.  
     
     
         21 . The device in accordance with  claim 15 , wherein said at least one cleaning device comprises at least one rotatable spray head arranged to traverse crosswise to the travel direction and arranged to rotate around an axis.  
     
     
         22 . The device in accordance with  claim 15 , wherein said at least one cleaning device emits a medium onto said surface under a pressure that is greater than approximately 20 bar.  
     
     
         23 . The device in accordance with  claim 22 , wherein said medium is under pressure less than about 30 bar.  
     
     
         24 . The device in accordance with  claim 22 , wherein said medium is under pressure less than about 25 bar.  
     
     
         25 . The device in accordance with  claim 15 , wherein said at least one cleaning device comprises a spray head which is rotatable around an axis, said spray head including at least one nozzle which is inclined relative to said axis.  
     
     
         26 . The device in accordance with  claim 25 , further comprising a vapor suctioning device, 
 wherein said spray head is assigned to said vapor suctioning device.    
     
     
         27 . The device in accordance with  claim 15 , further comprising a housing which is open to the at least one of the roll and the belt, wherein said at least one cleaning device is enclosed and/or surrounded by said housing.  
     
     
         28 . The device in accordance with  claim 27 , wherein said housing is sealed off from said surface by said at least two doctors.  
     
     
         29 . The device in accordance with  claim 1 , wherein the at least one of the roll and the belt comprises a grooved and/or blind bored surface, and is arranged to form a pressing nip, and said device further comprises a unit for evening out an amount of water supplied to said pressing nip.  
     
     
         30 . The device in accordance with  claim 29 , wherein said evening out unit comprises one of said at least two doctors.  
     
     
         31 . The device in accordance with  claim 30 , wherein in the one doctor is the first of the at least two doctors in the travel direction.  
     
     
         32 . The device in accordance with  claim 29 , wherein said evening out unit comprises a blowing device for blowing out grooves and/or blind bores in said surface with a pressurized medium.  
     
     
         33 . The device in accordance with  claim 32 , wherein said pressurized medium is pressurized air.  
     
     
         34 . The device in accordance with  claim 29 , wherein said evening out unit includes a suction device for suctioning water out of said surface.  
     
     
         35 . The device in accordance with  claim 29 , wherein said evening out unit includes a combined blowing and suction device.  
     
     
         36 . The device in accordance with  claim 29 , wherein said evening out unit includes a device for applying a hydrodynamically produced underpressure to said surface.  
     
     
         37 . The device in accordance with  claim 36 , wherein said device for applying hydrodynamically produced underpressure includes at least one of said at least two doctors.  
     
     
         38 . The device in accordance with  claim 37 , wherein said at least one doctor comprises a foil doctor arranged diagonally.  
     
     
         39 . The device in accordance with  claim 1 , wherein the at least one of the roll and the belt comprises a grooved and/or blind bored surface, and the device further comprises a unit for removing water from said grooved and/or blind bored surface, thereby increasing a dry content of a fibrous material web to be dewatered.  
     
     
         40 . The device in accordance with  claim 39 , wherein the fibrous material web comprises a paper or a cardboard web.  
     
     
         41 . The device in accordance with  claim 39 , wherein said water removal unit includes a blowing device for blowing out grooves and/or blind bores of said surface with a pressurized medium.  
     
     
         42 . The device in accordance with  claim 41 , wherein said pressurized medium comprises pressurized air.  
     
     
         43 . The device in accordance with  claim 39 , wherein said water removal unit includes a suction device for suctioning water out of said surface.  
     
     
         44 . The device in accordance with  claim 39 , wherein said water removal unit includes a combined blowing and suction device.  
     
     
         45 . The device in accordance with  claim 39 , wherein said water removal unit includes a device for applying a hydrodynamically produced underpressure to said surface.  
     
     
         46 . The device in accordance with  claim 45 , wherein said device for applying hydrodynamically produced underpressure includes at least one of said at least two doctors.  
     
     
         47 . The device in accordance with  claim 46 , wherein said at least one doctor comprises a foil doctor arranged diagonally.