Machine for washing fibrous suspensions

Abstract

A machine for washing fibrous suspensions has a pair of cylindrical drums; and a flexible belt with through holes carried by the drums. A conveyor carries the suspension to a contact line between the flexible belt and the first drum. A drive rotates at least one of the drums; and a collection received and pollutant agents; and another collection recess of the cellulose fibres. The conveyer has a head box below the flexible belt and upstream the first drum. The head box has a conveying conduit and) an outlet mouth transversally disposed with respect to the flexible belt. A flow conveyor, disposed between the head box and the first drum, has a laminar body with an inlet edge, downstream the outlet mouth, and an outlet edge, immediately upstream the contact line of the flexible belt with the first drum.

1 . A machine for washing fibrous suspensions composed by cellulose fibres and pollutant agents dispersed in a liquid, comprising: 
 a frame;    at least a pair of cylindrical drums with substantially parallel and mutually spaced axes;    a flexible belt provided with through holes and wound as a loop ring on said pair of cylindrical drums;    conveying means able to carry said fibrous suspension at the zone of incipient contact between said flexible belt and a first drum of said at least a pair of drums;    driving means able to put in rotation at least one of said drums to move forward said flexible belt;    collecting means of said liquid and said pollutant agents which are filtered through said flexible belt by the centrifugal force impressed to said fibrous suspension by the rotation of said first drum;    collecting means of said cellulose fibres contained in said fibrous suspension which are transferred from said flexible belt on the lateral surface of a second drum of said at least pair of drums,    wherein said conveying means comprise:    a head box disposed below said flexible belt and above said first drum, said head box comprising a conveying conduit of said fibrous suspension provided with an outlet mouth transversally disposed with respect to said flexible belt for at least a portion of its width;    a flow conveyor disposed between said head box and said first drum, said flow conveyor comprising a laminar body in which an inlet edge, disposed downstream said outlet mouth of said head box, and an outlet edge, disposed immediately upstream the contact line of said flexible belt with said first drum, are provided.    
   
   
       2 . The machine according to  claim 1 , wherein said laminar body has a shaped surface turned toward said flexible belt in which, starting from said inlet edge, a bent portion with the convexity turned toward said flexible belt is present, followed by a straight portion which ends with said outlet edge.  
   
   
       3 . The machine according to  claim 2 , wherein said straight portion is parallel disposed with respect to said flexible belt.  
   
   
       4 . The machine according to  claim 1 , wherein said laminar body is fixed to said conveying conduit of said head box.  
   
   
       5 . The machine according to  claim 1 , wherein said laminar body is joined to opening adjustment means of said outlet mouth of said conveying conduit.  
   
   
       6 . The machine according to  claim 5 , wherein said opening adjustment means of said outlet mouth comprise a sliding blade disposed on the width of said conveying conduit and provided on one side with screw means to fix connection means to said laminar body on said conveying conduit and on the opposite side.  
   
   
       7 . The machine according to  claim 6 , wherein the surface of said sliding blade turned toward the opposite side of said flexible belt is inclined with respect of said flexible belt at an angle having double amplitude with respect to the inclination angle of the corresponding surface of said laminar body, it too turned toward the opposite side of said flexible belt.  
   
   
       8 . The machine according to  claim 7 , wherein said surface of said laminar body turned toward the opposite side of said flexible belt abuts against a support structure fixed to said conveying means.  
   
   
       9 . The machine according to  claim 8 , wherein said surface of said laminar body has a substantially intermediate area abutting against said support structure.  
   
   
       10 . The machine according to  claim 6 , wherein said screw means comprise a plurality of screws, each of them being provided with a control wheel, passing through a corresponding slot obtained in said sliding blade and being screwed in a corresponding threaded hole obtained in said conveying conduit.  
   
   
       11 . The machine according to  claim 1 , wherein said flow conveyor is provided with side shoulders, applied to said laminar body, to contain said suspension of cellulose fibres.  
   
   
       12 . The machine according to  claim 1 , wherein it comprises thrust elastic means put in contact with the outer surface of said flexible belt on the opposite side with respect to said laminar body.  
   
   
       13 . The machine according to  claim 1 , wherein the outer surface of said first cylindrical drum comprises circumferential grooves.  
   
   
       14 . The machine according to  claim 1 , wherein said collecting means of said liquid and said pollutant agents filtered through said flexible belt consist of a first collecting tank placed below said first drum.  
   
   
       15 . The machine according to  claim 14 , wherein it further comprises a second collecting tank placed below said second drum.  
   
   
       16 . The machine according to  claim 1 , wherein said driving means comprise a motor coupled with a kinematic mechanism formed by a first pulley keyed to said motor, a second pulley keyed to said first drum and a transmission belt wound between said pulleys.  
   
   
       17 . The machine according to  claim 1 , wherein said collecting means of said cellulose fibres comprise at least a scraper, put in contact with the lateral surface of said second drum, and a container for collecting the fibres detached from said scraper, placed under said scraper.  
   
   
       18 . The machine according to  claim 17 , wherein said collecting container is provided with means for extracting said fibres.  
   
   
       19 . The machine according to  claim 18 , wherein said means for extracting said fibres consist of an auger.  
   
   
       20 . The machine according to  claim 1 , wherein said first drum is disposed at a higher level with respect to said second drum.  
   
   
       21 . (canceled)