Calender and method for controlling such a calender

Abstract

A calender includes a rotatable roller, and a belt, co-acting with the roller with a determined belt pressure. At least one material for feeding through the calender is situated between the roller and the belt for a determined contact time during throughfeed through the calender. The calender also includes heating means for heating the fluid and/or the roller, control means for controlling the heating means and/or the belt pressure and/or the contact time, and flow influencing means for initiating and/or influencing a flow of the fluid in the internal space. The control means are configured to control the flow influencing means and thereby the flow of the fluid in the internal space in freely settable manner. A set with a plurality of such calenders and a method for controlling such a calender.

1 - 25 . (canceled) 
     
     
         26 . A calender, comprising:
 a rotatable roller, which roller is hollow and thereby defines an internal space which is configured to be filled at least partially with a heatable fluid;   a belt, co-acting with the roller, with a determined belt pressure, wherein at least one material for feeding through the calender is situated between the roller and the belt for a determined contact time during throughfeed through the calender;   heating means for heating the fluid, which heating means are disposed in the internal space; and   one or more control means for controlling the heating means and/or the belt pressure and/or the contact time,   wherein the calender comprises flow influencing means for initiating and/or influencing a flow of the fluid in the internal space, wherein a further control means are configured to control the flow influencing means and thereby the flow of the fluid in the internal space in freely settable manner, such that a flow speed of the fluid can be set.   
     
     
         27 . The calender according to  claim 26 , wherein the control means are configured to control the flow influencing means such that a direction of the flow of the fluid is substantially opposite to a rotation direction of the roller. 
     
     
         28 . The calender according to  claim 26 , wherein the control means are configured to control the flow influencing means such that the flow regime of the fluid is variable between turbulent and laminar. 
     
     
         29 . The calender according to  claim 26 , wherein the flow influencing means comprise a rotatable rotor with a number of blades which are disposed in the roller, and further wherein:
 the calender comprises first drive means for rotatably driving the roller and second drive means for rotatably driving the rotor, wherein the control means are configured to control the first and second drive means separately of each other; and/or   the rotor comprises a cylindrical body disposed in the internal space of the roller, wherein the fluid is situated between the rotor and the roller, at least during use of the calender, wherein the blades extend outward from the cylindrical body, substantially in the direction of the roller.   
     
     
         30 . The calender according to  claim 26 , wherein the flow influencing means comprise at least one fluid conduit extending into the internal space and having at least one opening for supplying fluid from the at least one fluid conduit via the at least one opening to the internal space of the roller, and comprising at least one fluid discharge for discharging fluid from the internal space. 
     
     
         31 . The calender according to  claim 26 , further comprising:
 at least one first temperature sensor for measuring the temperature of an outer periphery of the roller, wherein the control means are configured to control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time on the basis of the measured outer periphery temperature; and   at least one second temperature sensor for measuring the temperature of the fluid, wherein the control means are further configured to control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time on the basis of the measured fluid temperature.   
     
     
         32 . The calender according to  claim 26 , comprising a database in which at least one of the following data is stored:
 a measured outer periphery temperature of the roller;   a or the measured fluid temperature;   the contact time;   the belt pressure;   a power of the heating means;   number of revolutions of the roller since the start of a calendering process;   at least one property of the at least one material being fed through the calender;   at least one property of a transfer paper being fed through the calender;   an ambient temperature;   an air humidity;   which calender is used;   a power of drive means of the calender; and   at least one property of a belt of the calender,   and wherein the control means are further configured to control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time on the basis of at least one of the data contained in the database.   
     
     
         33 . The calender according to  claim 32 , wherein the control means are configured to determine on the basis of at least periodically recorded settings of the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time of a plurality of prior calendering processes and on the basis of at least the at least one property of the same material how the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time must be set, and to control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time in the determined manner; and wherein the database and the control means are connectable to each other wirelessly or via a computer network. 
     
     
         34 . A set with a plurality of calenders according to  claim 26 , wherein the control means of at least one of the calenders are configured to control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time of that one calender on the basis of periodically registered data of calendering processes performed with the calenders of the set. 
     
     
         35 . A method for controlling a calender according to  claim 26 , which method comprises the following steps:
 a) setting or determining a setting of the flow influencing means; and   b) controlling the flow influencing means and thereby the flow of the fluid in the internal space by means of the control means so as to achieve the setting set or determined in step a), wherein a flow speed of the fluid is settable by the control in step b).   
     
     
         36 . The method according to  claim 35 , comprising controlling a calender comprising:
 a rotatable roller, which roller is hollow and thereby defines an internal space which is configured to be filled at least partially with a heatable fluid;   a belt, co-acting with the roller, with a determined belt pressure, wherein at least one material for feeding through the calender is situated between the roller and the belt for a determined contact time during throughfeed through the calender;   heating means for heating the fluid, which heating means are disposed in the internal space; and   one or more control means for controlling the heating means and/or the belt pressure and/or the contact time,   wherein the calender comprises flow influencing means for initiating and/or influencing a flow of the fluid in the internal space, wherein a further control means are configured to control the flow influencing means and thereby the flow of the fluid in the internal space in freely settable manner, such that a flow speed of the fluid can be set,   wherein the control means are configured to control the flow influencing means such that a direction of the flow of the fluid is substantially opposite to a rotation direction of the roller; and   wherein a direction of the flow of the fluid is set by the control in step b) to a direction which is substantially opposite to a rotation direction of the roller.   
     
     
         37 . The method according to  claim 35 , comprising controlling a calender comprising:
 a rotatable roller, which roller is hollow and thereby defines an internal space which is configured to be filled at least partially with a heatable fluid;   a belt, co-acting with the roller, with a determined belt pressure, wherein at least one material for feeding through the calender is situated between the roller and the belt for a determined contact time during throughfeed through the calender;   heating means for heating the fluid, which heating means are disposed in the internal space; and   one or more control means for controlling the heating means and/or the belt pressure and/or the contact time,   wherein the calender comprises flow influencing means for initiating and/or influencing a flow of the fluid in the internal space, wherein a further control means are configured to control the flow influencing means and thereby the flow of the fluid in the internal space in freely settable manner, such that a flow speed of the fluid can be set;   wherein the control means are configured to control the flow influencing means such that the flow regime of the fluid can vary between turbulent and laminar; and   wherein a flow regime of the fluid can be varied between turbulent and laminar by the control in step b).   
     
     
         38 . The method according to  claim 36 , wherein during a start-up phase and/or shutdown phase of a calendering process the flow influencing means are controlled by the control means in step b) such that the direction of the flow of the fluid is the first direction and/or the flow regime is turbulent. 
     
     
         39 . The method according to  claim 35 , comprising controlling a calender comprising:
 a rotatable roller, which roller is hollow and thereby defines an internal space which is configured to be filled at least partially with a heatable fluid;   a belt, co-acting with the roller, with a determined belt pressure, wherein at least one material for feeding through the calender is situated between the roller and the belt for a determined contact time during throughfeed through the calender;   heating means for heating the fluid, which heating means are disposed in the internal space; and   one or more control means for controlling the heating means and/or the belt pressure and/or the contact time,   wherein the calender comprises flow influencing means for initiating and/or influencing a flow of the fluid in the internal space, wherein a further control means are configured to control the flow influencing means and thereby the flow of the fluid in the internal space in freely settable manner, such that a flow speed of the fluid can be set;   wherein the flow influencing means comprise a rotatable rotor with a number of blades which is disposed in the roller, and further wherein:   the calender comprises first drive means for rotatably driving the roller and second drive means for rotatably driving the rotor, wherein the control means are configured to control the first and second drive means separately of each other; and/or   the rotor comprises a cylindrical body disposed in the internal space of the roller, wherein the fluid is situated between the rotor and the roller, at least during use of the calender, wherein the blades extend outward from the cylindrical body, substantially in the direction of the roller; and   wherein the first and second drive means are controlled separately of each other by the control means in step b).   
     
     
         40 . The method according to  claim 35 , comprising controlling a calender comprising:
 a rotatable roller, which roller is hollow and thereby defines an internal space which is configured to be filled at least partially with a heatable fluid;   a belt, co-acting with the roller, with a determined belt pressure, wherein at least one material for feeding through the calender is situated between the roller and the belt for a determined contact time during throughfeed through the calender;   heating means for heating the fluid, which heating means are disposed in the internal space; and   one or more control means for controlling the heating means and/or the belt pressure and/or the contact time,   wherein the calender comprises flow influencing means for initiating and/or influencing a flow of the fluid in the internal space, wherein a further control means are configured to control the flow influencing means and thereby the flow of the fluid in the internal space in freely settable manner, such that a flow speed of the fluid can be set;   at least one first temperature sensor for measuring the temperature of an outer periphery of the roller, wherein the control means are configured to control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time on the basis of the measured outer periphery temperature; and   at least one second temperature sensor for measuring the temperature of the fluid, wherein the control means are further configured to control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time on the basis of the measured fluid temperature;   which method further comprises the step c) of measuring the temperature of an outer periphery of the roller with the at least one first temperature sensor, and the control means control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time on the basis of the outer periphery temperature measured in step c).   
     
     
         41 . The method according to  claim 40 , further comprising the step d) of setting or determining a target temperature for the outer periphery of the roller, and wherein in step a) the desired setting is determined on the basis of the difference between the outer periphery temperature measured in step c) and the target temperature set in step d); and
 controlling a calender comprising:
 a rotatable roller, which roller is hollow and thereby defines an internal space which is configured to be filled at least partially with a heatable fluid; 
 a belt, co-acting with the roller, with a determined belt pressure, wherein at least one material for feeding through the calender is situated between the roller and the belt for a determined contact time during throughfeed through the calender; 
 heating means for heating the fluid, which heating means are disposed in the internal space; and 
 one or more control means for controlling the heating means and/or the belt pressure and/or the contact time, 
   wherein the calender comprises flow influencing means for initiating and/or influencing a flow of the fluid in the internal space, wherein a further control means are configured to control the flow influencing means and thereby the flow of the fluid in the internal space in freely settable manner, such that a flow speed of the fluid can be set;   wherein the control means are configured to control the flow influencing means such that a direction of the flow of the fluid is substantially opposite to a rotation direction of the roller; and   wherein the flow influencing means are controlled by the control means in step b) such that the direction of the flow of the fluid is the direction opposite to the rotation direction of the roller and/or the flow regime is turbulent if the difference between the outer periphery temperature measured in step c) and the target temperature set or determined in step d) is greater than a determined value, and, that the flow regime is laminar or the speed of the flow is almost 0 m/s if the difference between the outer periphery temperature measured in step c) and the target temperature set or determined in step d) is smaller than a determined value.   
     
     
         42 . The method according to  claim 35 , comprising controlling a calendar comprising:— a rotatable roller, which roller is hollow and thereby defines an internal space which is configured to be filled at least partially with a heatable fluid;
 a belt, co-acting with the roller, with a determined belt pressure, wherein at least one material for feeding through the calender is situated between the roller and the belt for a determined contact time during throughfeed through the calender; 
 heating means for heating the fluid, which heating means are disposed in the internal space; and 
 one or more control means for controlling the heating means and/or the belt pressure and/or the contact time, 
 wherein the calender comprises flow influencing means for initiating and/or influencing a flow of the fluid in the internal space, wherein a further control means are configured to control the flow influencing means and thereby the flow of the fluid in the internal space in freely settable manner, such that a flow speed of the fluid can be set; 
 at least one first temperature sensor for measuring the temperature of an outer periphery of the roller, wherein the control means are configured to control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time on the basis of the measured outer periphery temperature; and 
 at least one second temperature sensor for measuring the temperature of the fluid, wherein the control means are further configured to control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time on the basis of the measured fluid temperature; 
 which method further comprises the step e) of measuring the temperature of the fluid with the at least one second temperature sensor, and wherein the control means control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time on the basis of the fluid temperature measured in step e). 
 
     
     
         43 . The method according to  claim 35 , comprising controlling a calendar comprising:
 a rotatable roller, which roller is hollow and thereby defines an internal space which is configured to be filled at least partially with a heatable fluid;   a belt, co-acting with the roller, with a determined belt pressure, wherein at least one material for feeding through the calender is situated between the roller and the belt for a determined contact time during throughfeed through the calender;   heating means for heating the fluid, which heating means are disposed in the internal space; and   one or more control means for controlling the heating means and/or the belt pressure and/or the contact time,   wherein the calender comprises flow influencing means for initiating and/or influencing a flow of the fluid in the internal space, wherein a further control means are configured to control the flow influencing means and thereby the flow of the fluid in the internal space in freely settable manner, such that a flow speed of the fluid can be set; the calender further comprising a database in which at least one of the following data is stored:   a measured outer periphery temperature of the roller;   a or the measured fluid temperature;   the contact time;   the belt pressure;   a power of the heating means;   number of revolutions of the roller since the start of a calendering process;   at least one property of the at least one material being fed through the calender;   at least one property of a transfer paper being fed through the calender;   an ambient temperature;   an air humidity;   which calender is used;   a power of drive means of the calender; and   at least one property of a belt of the calender,   wherein the control means are further configured to control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time on the basis of at least one of the data contained in the database; and   wherein the control means control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time on the basis of the data contained in the database.   
     
     
         44 . The method according to  claim 35 , comprising controlling a calendar comprising:
 a rotatable roller, which roller is hollow and thereby defines an internal space which is configured to be filled at least partially with a heatable fluid;   a belt, co-acting with the roller, with a determined belt pressure, wherein at least one material for feeding through the calender is situated between the roller and the belt for a determined contact time during throughfeed through the calender;   heating means for heating the fluid, which heating means are disposed in the internal space; and   one or more control means for controlling the heating means and/or the belt pressure and/or the contact time,   wherein the calender comprises flow influencing means for initiating and/or influencing a flow of the fluid in the internal space, wherein a further control means are configured to control the flow influencing means and thereby the flow of the fluid in the internal space in freely settable manner, such that a flow speed of the fluid can be set;   wherein the control means of at least one of the calenders are configured to control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time of that one calender on the basis of periodically registered data of calendering processes performed with the calenders of the set; and   wherein the control means of said one calender control the flow influencing means and/or the heating means and/or the belt pressure and/or the contact time on the basis of periodically registered data from calendering processes performed with a plurality of calenders of the set.   
     
     
         45 . The method according to  claim 35 , wherein at least one step of the method is performed iteratively.