Heated cylinder

Abstract

Disclosed is a heated cylinder ( 1 ) for heating a paper web, cardboard web, tissue web, or another fiber web in a machine used for producing and/or refining the fiber web. Said heated cylinder ( 1 ) comprises a cylinder sleeve which is impinged upon at least in part from the inside by a hot fluid and is provided with at least one inner and an outer sleeve layer ( 5, 6 ). The inventive heated cylinder ( 1 ) is characterized in that the two sleeve layers ( 5, 6 ) are separated from each other by a hollow space into which the fluid can be introduced.

1 . A heated cylinder comprising: 
 a cylinder sleeve having at least one inner sleeve layer and one outer sleeve layer,    wherein the at least one inner sleeve layer and one outer sleeve layer are separated from each other by a hollow space into which the fluid can be introduced.    
   
   
       2 . The heated cylinder according to  claim 1 , wherein the inner sleeve layer is thicker than the outer sleeve layer.  
   
   
       3 . The heated cylinder according to  claim 1 , wherein the outer sleeve layer has a wall thickness from 8 to 15 mm.  
   
   
       4 . The heated cylinder according to  claim 1 , wherein the fluid is steam and the steam in the hollow space between the two sleeve layers has a positive pressure of between 2 and 13 bar.  
   
   
       5 . The heated cylinder according to  claim 1 , further comprising: 
 a rib structure selected from at least one of ribs extending in axial or circumferential direction or having a helical shape, a honeycomb structure, or a lattice structure,    and wherein the ribs are formed on to the inner surface of the outer sleeve layer facing the hollow space.    
   
   
       6 . The heated cylinder according to  claim 5 , wherein the rib, honeycomb or lattice structure is comprised of a material with a high thermal conductivity.  
   
   
       7 . The heated cylinder according to  claim 5 , wherein the surface area of the rib, honeycomb or lattice structure is ten to one hundred times greater than the inner surface of the outer sleeve layer.  
   
   
       8 . The heated cylinder according to  claim 1 , wherein the outer sleeve layer comprises a material with a high thermal conductivity.  
   
   
       9 . The heated cylinder according to  claim 8 , wherein the outer sleeve layer is comprises boiler steel.  
   
   
       10 . The heated cylinder according to  claim 1 , wherein the inner sleeve layer has a high modulus of elasticity.  
   
   
       11 . The heated cylinder according to  claim 1 , wherein the pipes between the inner and the outer sleeve layer are connected via rotary bushings to a fixed steam supply or an exhaust steam and condensed water tank.  
   
   
       12 . The heated cylinder according to  claim 1 , wherein the inner sleeve layer comprises a rigid core which absorbs loads acting on the outer sleeve layer.  
   
   
       13 . The heated cylinder according to  claim 1 , wherein the inner and the outer sleeve layer are connected by at least one of bars, pins, screws, and rivets.  
   
   
       14 . The heated cylinder according to  claim 1 , further comprising platelets are attached between the inner and the outer sleeve layer.  
   
   
       15 . The heated cylinder according to  claim 14 , wherein the platelets are arranged parallel to each other, crosswise, helically, or in a honeycomb or lattice structure.  
   
   
       16 . The heated cylinder according to  claim 14 , wherein the platelets have a flat or a profiled surface.  
   
   
       17 . The heated cylinder according to  claim 14 , wherein the platelets become wider in the direction of the outer sleeve layer.  
   
   
       18 . The heated cylinder according to  claim 5 , wherein the surface of the rib, honeycomb or lattice structure on the inner side of the outer sleeve layer at the circumferential end becomes smaller near the end faces of the cylinder.  
   
   
       19 . A heated cylinder comprising: 
 one outer cylinder sleeve,    wherein the outer cylinder sleeve is supported by struts inside the heated cylinder.    
   
   
       20 . The heated cylinder according to  claim 6 , wherein the material having high thermal conductivity is selected from copper or aluminum.  
   
   
       21 . The heated cylinder according to  claim 15 , wherein the platelets are further arranged in an axial direction of the cylinder.  
   
   
       22 . A machine for producing and/or refining a paper web, cardboard web, tissue web or some other fiber web, comprising the heated cylinder according to  claim 1 .  
   
   
       23 . A machine for producing and/or refining a paper web, cardboard web, tissue web or some other fiber web, comprising the heated cylinder according to  claim 19.