Paper machine

Abstract

A paper machine for stable high-speed papermaking without slackness of wet web, the paper machine including the most downstream press unit along the transfer path of the wet web in the press part, and the most upstream dryer unit and the second upstream dryer unit along the transfer path of the wet web in the dryer part are associated with three different belt mechanisms, respectively, so that the driving units of the three driving units associated with the most downstream press unit and the first and second upstream dryer units are individually controlled so that a transfer speed of the wet web along each of the most downstream press unit and the first and second upstream dryer units is individually set.

What is claimed is:  
     
         1 . A paper machine comprising: 
 a plurality of belt mechanisms for transferring a wet web which is formed by a wire part, each of said belt mechanisms having a belt for supporting the wet web and a driving unit for driving said belt together with the wet web;    a press part including one or more press units, arranged along a transfer path of the web, for pressing the wet web so that the wet web is dewatered; and    a dryer part including a plurality of dryer units, arranged along the transfer path of the wet web, for drying the wet web, which has been dewatered in said press part, by heat; wherein 
 a last press unit, that is the most downstream one of the one or more press units along the transfer path of the wet web in said press part, a first dryer unit, that is the most upstream one of the plural dryer units along the transfer path of the wet web in said dryer part, and a second dryer unit, that is the second upstream one of the plural dryer units along the transfer path of the wet web in said dryer part, are associated with three of said belt mechanisms, respectively, and  
 said driving units of the last-named three belt mechanisms, which are associated with said last press unit, said first dryer unit and said second dryer unit, respectively, are individually controlled so that a transfer speed of the wet web along each of said last press unit, said first dryer unit and said second dryer unit is individually set.  
   
     
     
         2 . Paper machine according to  claim 1 , wherein: 
 the transfer speed of the wet web along said first dryer unit is set to be higher than the transfer speed of the wet web along said last press unit; and    the transfer speed of the wet web along said second dryer unit is set to be higher than the transfer speed along said first dryer unit.    
     
     
         3 . A paper machine according to  claim 1 , wherein the transfer speed of the wet web along said first dryer unit is set to be higher than the transfer speed of the wet web along said last press unit by a factor equal to or less than 1.04.  
     
     
         4 . A paper machine according to  claim 2 , wherein the transfer speed of the wet web along said first dryer unit is set to be higher than the transfer speed of the wet web along said last press unit by a factor equal to or less than 1.04.  
     
     
         5 . A paper machine according to  claim 1 , wherein the transfer speed of the wet web along said second dryer unit is higher than the transfer speed of the wet web along said first dryer unit by a factor equal to or less than 1.01.  
     
     
         6 . A paper machine according to  claim 2 , wherein the transfer speed of the wet web along said second dryer unit is higher than the transfer speed of the wet web along said first dryer unit by a factor equal to or less than 1.01.  
     
     
         7 . A paper machine according to  claim 3 , wherein the transfer speed of the wet web along said second dryer unit is higher than the transfer speed of the wet web along said first dryer unit by a factor equal to or less than 1.01.  
     
     
         8 . A paper machine according to  claim 4 , wherein the transfer speed of the wet web along said second dryer unit is higher than the transfer speed of the wet web along said first dryer unit by a factor equal to or less than 1.01.  
     
     
         9 . A paper machine according to  claim 1 , wherein: 
 said dryer part has one or more other dryer units other than said first and second dryer units, which other dryer units are arranged downstream of said first and second dryer units;    said second dryer unit and one of said other dryer units are associated with two of said belt mechanisms, respectively; and    a transfer speed of the wet web along said last-named one dryer unit is set to be higher than the transfer speed of the wet web along said second dryer unit by a factor equal to or less than 1.01.    
     
     
         10 . A paper machine according to  claim 2 , wherein: 
 said dryer part has one or more other dryer units other than said first and second dryer units, which other dryer units are arranged downstream of said first and second dryer units;    said second dryer unit and one of said other dryer units are associated with two of said belt mechanisms, respectively; and    a transfer speed of the wet web along said last-named one dryer unit is set to be higher than the transfer speed of the wet web along said second dryer unit by a factor equal to or less than 1.01.    
     
     
         11 . A paper machine according to  claim 3 , wherein: 
 said dryer part has one or more other dryer units other than said first and second dryer units, which other dryer units are arranged downstream of said first and second dryer units;    said second dryer unit and one of said other dryer units are associated with two of said belt mechanisms, respectively; and    a transfer speed of the wet web along said last-named one dryer unit is set to be higher than the transfer speed of the wet web along said second dryer unit by a factor equal to or less than 1.01.    
     
     
         12 . A paper machine according to  claim 4 , wherein: 
 said dryer part has one or more other dryer units other than said first and second dryer units, which other dryer units are arranged downstream of said first and second dryer units;    said second dryer unit and one of said other dryer units are associated with two of said belt mechanisms, respectively; and    a transfer speed of the wet web along said last-named one dryer unit is set to be higher than the transfer speed of the wet web along said second dryer unit by a factor equal to or less than 1.01.    
     
     
         13 . A paper machine according to  claim 5 , wherein: 
 said dryer part has one or more other dryer units other than said first and second dryer units, which other dryer units are arranged downstream of said first and second dryer units;    said second dryer unit and one of said other dryer units are associated with two of said belt mechanisms, respectively; and    a transfer speed of the wet web along said last-named one dryer unit is set to be higher than the transfer speed of the wet web along said second dryer unit by a factor equal to or less than 1.01.    
     
     
         14 . A paper machine according to  claim 6 , wherein: 
 said dryer part has one or more other dryer units other than said first and second dryer units, which other dryer units are arranged downstream of said first and second dryer units;    said second dryer unit and one of said other dryer units are associated with two of said belt mechanisms, respectively; and    a transfer speed of the wet web along said last-named one dryer unit is set to be higher than the transfer speed of the wet web along said second dryer unit by a factor equal to or less than 1.01.    
     
     
         15 . A paper machine according to  claim 7 , wherein: 
 said dryer part has one or more other dryer units other than said first and second dryer units, which other dryer units are arranged downstream of said first and second dryer units;    said second dryer unit and one of said other dryer units are associated with two of said belt mechanisms, respectively; and    a transfer speed of the wet web along said last-named one dryer unit is set to be higher than the transfer speed of the wet web along said second dryer unit by a factor equal to or less than 1.01.    
     
     
         16 . A paper machine according to  claim 8 , wherein: 
 said dryer part has one or more other dryer units other than said first and second dryer units, which other dryer units are arranged downstream of said first and second dryer units;    said second dryer unit and one of said other dryer units are associated with two of said belt mechanisms, respectively; and    a transfer speed of the wet web along said last-named one dryer unit is set to be higher than the transfer speed of the wet web along said second dryer unit by a factor equal to or less than 1.01.