Closed system cooled covered roll and methods of forming and operating cooled covered roll

Abstract

Roll, method of forming roll and method of operating roll. Roll includes a roll body, a deformable cover coupled to the roll body, a pluggable input, a pluggable output, and a coolant contained within the roll body at least in an amount sufficient for a rimming mode to occur during normal operation of the roll. The present abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

1 . A roll comprising:
 a roll body;   a deformable cover coupled to the roll body;   at least one pluggable input; and   a coolant contained within the roll body at least in an amount to provide cross-machine direction heat transfer during normal operation of the roll.   
   
   
       2 . The roll in accordance with  claim 1 , wherein the roll is a cooled roll operable as a closed system. 
   
   
       3 . The roll in accordance with  claim 1 , wherein the at least an amount of coolant to provide cross-machine direction heat transfer comprises an amount greater than an amount of coolant sufficient for at least a rimming mode to occur. 
   
   
       4 . The roll in accordance with  claim 1 , wherein the at least an amount of coolant to provide cross-machine direction heat transfer is determined by a difference in steady state power between operation of the roll with fluid flowing through the input and output of the roll and operation of the roll without coolant. 
   
   
       5 . The roll in accordance with  claim 1 , wherein the at least an amount of coolant to provide cross-machine direction heat transfer provides a volume fraction of greater than or equal to 1%. 
   
   
       6 . The roll in accordance with  claim 5 , wherein the volume fraction comprises a volume of the coolant inside the roll divided by a total inner volume of the roll body. 
   
   
       7 . The roll in accordance with  claim 1 , further comprising a siphon with a siphon pick-up shoe positioned near an inner surface of the roll body, wherein the at least an amount of coolant to provide cross-machine direction heat transfer is greater than or equal to a distance between the inner surface of the roll body and a tip of the siphon pick-up shoe. 
   
   
       8 . The roll in accordance with  claim 1 , wherein the at least an amount of coolant to provide cross-machine direction heat transfer is determined by the following equation: 
     Where: Δ [m 3 ] represents the fluid volume in the roll body
 D 0  [m] represents the outer diameter of the covered roll; 
 L [m] represents the length of the internal cavity inside the roll body; 
 t c  [m] represents the total cover thickness; 
 t s  [m] represents the roll shell thickness of the roll body; 
 V [m/sec] represents the surface speed of the covered roll; 
 ν [m 2 /sec] represents the dynamic viscosity of coolant; and 
 g [m/sec 2 ] represents the standard acceleration of gravity (9.80665 m/sec 2 .). 
 
   
   
       9 . A method for forming a cooled roll composed of a single shell covered roll having an open internal cavity, comprising:
 adding coolant into the internal cavity at least in an amount to provide cross-machine direction heat transfer during normal operation of the roll; and   plugging a pluggable input of the roll.   
   
   
       10 . The method in accordance with  claim 9 , wherein the at least an amount of added coolant comprises an amount greater than an amount of coolant sufficient for at least a rimming mode to occur. 
   
   
       11 . The method in accordance with  claim 9 , wherein, before the adding of coolant, the method further comprises:
 determining a steady state power for operating with fluid flowing through the roll;   determining a steady state power for operating the roll without coolant; and   determining the difference in steady state power between operation of the roll with fluid flowing through the roll and operation of the roll without coolant,   wherein the at least an amount of coolant added to the cavity is found when steady state power to the roll with the added amount is at least equal to the determined difference in steady state power.   
   
   
       12 . The method in accordance with  claim 9 , wherein the at least an amount of added coolant provides a volume fraction of greater than or equal to 1%. 
   
   
       13 . The method in accordance with  claim 12 , wherein the volume fraction comprises a volume of the coolant inside the roll divided by a total inner volume of the roll body. 
   
   
       14 . The method in accordance with  claim 9 , wherein the roll is further composed of a siphon with a siphon pick-up shoe positioned near an inner surface of the roll body, and
 wherein the at least an amount of added coolant is greater than or equal to a distance between the inner surface of the roll body and a tip of the siphon pick-up shoe.   
   
   
       15 . The method in accordance with  claim 9 , wherein the at least an amount of added coolant is determined by the following equation: 
     Where: Δ [m 3 ] represents the fluid volume in the roll body
 D 0  [m] represents the outer diameter of the covered roll; 
 L [m] represents the length of the internal cavity inside the roll body; 
 t c  [m] represents the total cover thickness; 
 t s  [m] represents the roll shell thickness of the roll body; 
 V [m/sec] represents the surface speed of the covered roll; 
 ν [m 2 /sec] represents the dynamic viscosity of coolant; and 
 g [m/sec 2 ] represents the standard acceleration of gravity (9.80665 m/sec 2 ). 
 
   
   
       16 . The method in accordance with  claim 9 , wherein the cooled roll is operated as a closed system. 
   
   
       17 . A method for operating a roll of a paper machine composed of a single shell covered roll having an open internal cavity, comprising:
 adding an amount of coolant into the internal cavity in an amount greater than an amount for operating in a rimming mode during normal operation of the roll;   plugging a pluggable input of the roll; and   rotating the roll.   
   
   
       18 . The method in accordance with  claim 17 , wherein the roll includes a roll cover and the coolant cools heat created by deforming the roll cover. 
   
   
       19 . The method in accordance with  claim 17 , wherein rotation of the roll provides cooling in a machine direction and in a cross-machine direction. 
   
   
       20 . The method in accordance with  claim 17 , wherein the coolant has a dynamic viscosity of less than 10 −5  m 2 /sec.