Headbox for a paper machine

Abstract

The invention relates to a headbox for a paper machine, comprising: a plurality of distributor-dampening devices; each distributor-dampening device comprising an upright vessel, said vessel having at its bottom a central inlet for feeding of a pulp suspension, a plurality of sectional flow pipes, each being located at the same height and arranged unitormly around the circumference of the said vessel, further comprising dilution water lines for metering of dilution water into each sectional flow pipe; a forming unit having a slit shaped outlet channel extending at least approximately over the width of the paper machine for dispensing of a flat stream of pulp suspension; the sectional flow pipes of each of the distributors being connected to the outlet channel, each of the said sectional flow pipes at least of approximately have the same length.

1 . Headbox for a paper machine, comprising: 
 a plurality of distributor-dampening devices;    each distributor-dampening device comprising an upright vessel, said vessel having at its bottom a central inlet for feeding of a pulp suspension, a plurality of sectional flow pipes, each being located at the same height and arranged uniformly around the circumference of the said vessel, furthor comprising dilution water lines for metering of dilution water into each sectional flow pipe;    a forming unit having a slit shaped outlet channel extending at least approximately over the width of the paper machine for dispensing of a flat stream of pulp suspension;    the sectional flow pipes of each of the distributors being connected to the outlet channel, each of the said sectional flow pipes at least of approximately have the same length.    
   
   
       2 . Headbox according to  claim 1 , characterized in that the width of the outlet channel is divided into a number of portions corresponding to the number of distributors, and that one of each said distributors feeds a sectional flow of pulp suspension to a respective portion.  
   
   
       3 . Headbox according to  claim 1 , characterized in that the said distributors are identical or approximately identical with regard to design and dimensions.  
   
   
       4 . Headbox according to  claim 1 , characterized in that pulp suspension is delivered by a main feed pipe which is branching into a number of pipes corresponding to the number of distributors, each branching pipe being connected to one of the said distributors.  
   
   
       5 . Headbox according to  claim 1 , characterized that there is provided a main distributor-dampening device located upstream of the said distributor-damping devices and being of similar or identical design, but bigger in size than the same.  
   
   
       6 . Headbox according to  claim 1 , characterized in that the distributors are connected to each other by a liquid level equalizing line connected above the outlets of the sectional flow pipes to the dome.  
   
   
       7 . Headbox according to one of  claims 1  to  6   claim 1  characterized that neighboured distributors are connected to each other by liquid level equalizing lines.  
   
   
       8 . Headbox according to  claim 7 , characterized in that at least one of the said liquid level equalizing line comprises a pressure equalizing vessel.  
   
   
       9 . Combination of a plurality of headboxes according to  claim 1  for a paper machine intended for the formation of multi layer sheets, comprising forming units for each layer, each forming unit being connected to the same number or different numbers of distributors.  
   
   
       10 . Headbox according to  claim 2 , characterized in that the said distributors are identical or approximately identical with regard to design and dimensions.  
   
   
       11 . Headbox according to  claim 2 , characterized in that pulp suspension is delivered by a main feed pipe which is branching into a number of pipes corresponding to the number of distributors, each branching pipe being connected to one of the said distributors.  
   
   
       12 . Headbox according to  claim 3 , characterized in that pulp suspension is delivered by a main feed pipe which is branching into a number of pipes corresponding to the number of distributors, each branching pipe being connected to one of the said distributors.  
   
   
       13 . Headbox according to  claim 2 , characterized that there is provided a main distributor-dampening device located upstream of the said distributor-damping devices and being of similar or identical design, but bigger in size than the same.  
   
   
       14 . Headbox according to  claim 3 , characterized that there is provided a main distributor-dampening device located upstreams of the said distributor-damping devices and being of similar or identical design, but bigger in size than the same.  
   
   
       15 . Headbox according to  claim 4 , characterized that there is provided a main distributor-dampening device located upstreams of the said distributor-damping devices and being of similar or identical design, but bigger in size than the same.  
   
   
       16 . Headbox according to  claim 2 , characterized in that the distributors are connected to each other by a liquid level equalizing line connected above the outlets of the sectional flow pipes to the dome.  
   
   
       17 . Headbox according to  claim 3 , characterized in that the distributors are connected to each other by a liquid level equalizing line connected above the outlets of the sectional flow pipes to the dome.  
   
   
       18 . Headbox according to  claim 4 , characterized in that the distributors are connected to each other by a liquid level equalizing line connected above the outlets of the sectional flow pipes to the dome.  
   
   
       19 . Headbox according to  claim 5 , characterized in that the distributors are connected to each other by a liquid level equalizing line connected above the outlets of the sectional flow pipes to the dome.  
   
   
       20 . Headbox according to  claim 2 , characterized that neighboured distributors are connected to each other by liquid level equalizing lines.