Process and apparatus for reordering expanded tobacco

Abstract

A process reorders tobacco that has been expanded by impregnating the tobacco under pressure with liquid carbon dioxide, forming a frozen mass of the tobacco and carbon dioxide, and heating the frozen mass in an expansion zone to sublimate the carbon dioxide and thereby expand the tobacco. The expanded tobacco is discharged from the expansion zone and before the temperature of the expanded tobacco is below about 80° F. and preferably when the expanded tobacco is at an elevated temperature of between about 180° F. and about 212° F., the tobacco is contacted with humidifying air having a temperature of about 80° F. to about 91° F. and a relative humidity of about 58% to about 88%.

What is claimed is:  
     
         1 . A process for increasing the moisture content of expanded tobacco comprising contacting expanded tobacco having an initial moisture content of less than about 8% and an initial temperature of at least about 180° F. with an air stream having a relative humidity of from about 58% to about 88% and a temperature of from about 68° F. to about 91° F.  
     
     
         2 . The process of  claim 1 , wherein the expanded tobacco is disposed on a vibrating conveyor having an air permeable floor, the air stream flowing upwardly through the floor before contacting the expanded tobacco.  
     
     
         3 . The process of  claim 2 , wherein the expanded tobacco forms a tobacco bed on the floor of the conveyer, the tobacco bed having a depth of from about 0.10 inches to about 20 inches.  
     
     
         4 . The process of  claim 2 , wherein the air stream flows at a velocity of from about 10 CFM to about 120 CFM per square foot of the conveyor floor.  
     
     
         5 . The process of  claim 1 , wherein the moisture content of the expanded tobacco is increased from less than about 8% to at least about 12% in less than 20 minutes after first being contacted by the air stream.  
     
     
         6 . The process of  claim 1 , wherein the moisture content of the expanded tobacco is increased from less than about 8% to at least about 12% in from about 6 minutes to about 20 minutes after first being contacted by the air stream.  
     
     
         7 . The process of  claim 1 , wherein the expanded tobacco is cut tobacco filler.  
     
     
         8 . The process of  claim 1 , wherein the relative humidity of the air stream is from about 68% to about 78%.  
     
     
         9 . The process of  claim 1 , wherein the relative humidity of the air stream is about 78%.  
     
     
         10 . The process of  claim 9 , wherein the temperature of the air stream is about 90° F.  
     
     
         11 . A process for increasing the moisture content of expanded tobacco comprising contacting the expanded tobacco with an air stream having a temperature of from about 68° F. to about 91° F. and a relative humidity of from about 58% to about 88% as the temperature of the expanded tobacco decreases from an elevated temperature of at least about 180° F. to ambient temperature.  
     
     
         12 . The process of  claim 11 , wherein the expanded tobacco is disposed on a vibrating conveyor having an air permeable floor, the air stream flowing upwardly through the floor before contacting the expanded tobacco.  
     
     
         13 . The process of  claim 12 , wherein the expanded tobacco forms a tobacco bed on the floor of the conveyer, the tobacco bed having a depth of from about 0.10 inches to about 20 inches.  
     
     
         14 . The process of  claim 12 , wherein the air stream flows at a velocity of from about 10 CFM to about 120 CFM per square foot of the conveyor floor.  
     
     
         15 . The process of  claim 11 , wherein the moisture content of the expanded tobacco is increased from less than about 8% to at least about 12% in less than 20 minutes after first being contacted by the air stream.  
     
     
         16 . The process of  claim 11 , wherein the moisture content of the expanded tobacco is increased from less than about 8% to at least about 12% in from about 6 minutes to about 20 minutes after first being contacted by the air stream.  
     
     
         17 . The process of  claim 11 , wherein the expanded tobacco is cut tobacco filler.  
     
     
         18 . The process of  claim 11 , wherein the relative humidity of the air stream is from about 68% to about 78%.  
     
     
         19 . The process of  claim 11 , wherein the relative humidity of the air stream is about 78%.  
     
     
         20 . The process of  claim 19 , wherein the temperature of the air stream is about 90° F.  
     
     
         21 . A process for increasing the moisture content of expanded tobacco having an elevated temperature of at least about 180° F. when discharged from an expansion chamber, comprising contacting the expanded tobacco with an air stream having a temperature of from about 68° F. to about 91° F. and a relative humidity of from about 58% to about 88% before the temperature of the expanded tobacco decreases to ambient temperature.  
     
     
         22 . The process of  claim 21 , wherein the expanded tobacco is discharged from the expansion chamber onto a vibrating conveyor having an air permeable floor, the air stream flowing upwardly through the floor before contacting the expanded tobacco.  
     
     
         23 . The process of  claim 22 , wherein the expanded tobacco forms a tobacco bed on the floor of the conveyer, the tobacco bed having a thickness of from about 0.10 inches to about 20 inches.  
     
     
         24 . The process of  claim 22 , wherein the air stream flows at a velocity of from about 10 CFM to about 120 CFM per square foot of the floor.  
     
     
         25 . The process of  claim 21 , wherein the expanded tobacco is discharged from the expansion chamber into a heated chamber before being contacted with the humidified air stream.  
     
     
         26 . The process of  claim 25 , wherein the heated chamber comprises an enclosed heated conveyor.  
     
     
         27 . The process of  claim 21 , wherein the moisture content of the expanded tobacco is increased from less than about 8% to at least about 12% in less than 20 minutes after first being contacted by the air stream.  
     
     
         28 . The process of  claim 28 , wherein the moisture content of the expanded tobacco is increased from less than about 8% to at least about 12% in from about 6 minutes to about 20 minutes after first being contacted by the air stream.  
     
     
         29 . The process of  claim 21 , wherein the expanded tobacco is cut tobacco filler.  
     
     
         30 . The process of  claim 21 , wherein the relative humidity of the air stream is from about 68% to about 78%.  
     
     
         31 . The process of  claim 21 , wherein the relative humidity of the air stream is about 78%.  
     
     
         32 . The process of  claim 31 , wherein the wherein the temperature of the air stream is about 90° F.  
     
     
         33 . A process for increasing the moisture content of expanded tobacco, comprising: 
 (a) disposing expanded tobacco having an initial moisture content of less than about 8% and an initial temperature of at least about 180° F. on a conveyor having an air permeable floor, the tobacco forming a tobacco bed having a depth of about 9 inches; and    (b) contacting the expanded tobacco for about 11 minutes with an air stream having a relative humidity of about 78%, a temperature of about 91° F. and a velocity of about 110 CFM per sq. ft. of the floor.    
     
     
         34 . An apparatus for increasing the moisture content of expanded tobacco, comprising: 
 (a) an expansion zone for increasing the fill value of cut tobacco filler, the expansion zone having an outlet for discharging expanded tobacco having a moisture content of less than about 8% and an elevated temperature of at least about 180° F.; and    (b) a reordering zone downstream of the expansion zone for receiving the expanded tobacco discharged from the expansion zone outlet, the reordering zone having a blower for blowing an air stream having a relative humidity of from about 58% to about 88% and a temperature of from about 68° F. to about 91° F. through expanded tobacco having an initial moisture content of less than about 8% and an initial temperature of at least about 180° F.    
     
     
         35 . The apparatus of  claim 34 , wherein the reordering zone comprises a conveyor having an air permeable floor, the air stream flowing upwardly through the floor before flowing through the expanded tobacco.  
     
     
         36 . The apparatus of  claim 35 , wherein the conveyor is a vibrating conveyor.  
     
     
         37 . The apparatus of  claim 35 , wherein the conveyor is a moving belt conveyor.  
     
     
         38 . The apparatus of  claim 35 , wherein the air stream has a relative humidity of about 78%, a temperature of about 90° F. and a velocity of about 110 CFM per sq. ft. of the conveyor floor.  
     
     
         39 . The apparatus of  claim 34  further comprising a heated chamber for receiving the expanded tobacco discharged from the expansion zone and delivering the expanded tobacco to the reordering zone.  
     
     
         40 . The apparatus of  claim 39 , wherein the heated chamber comprises an enclosed heated conveyor.  
     
     
         41 . A process for preventing the propagation of fire in a bed of expanded tobacco discharged from an expansion zone, comprising: 
 (a) forming a bed of expanded tobacco having a depth of between about 0.10 inch and about 20 inches on a conveyor having an air permeable floor; and    (b) contacting the expanded tobacco with an air stream having a velocity of from about 10 CFM to about 120 CFM per square foot of the conveyor floor to create a fluidized bed of expanded tobacco.    
     
     
         42 . The process according to  claim 41 , wherein the bed of expanded tobacco has a depth of about 9 inches and the air stream has a velocity of about 110 CFM per sq. ft. of the conveyor floor.