Method and apparatus for expanding tobacco material

Abstract

A tobacco material expansion method includes the steps of wetting and swelling a tobacco material by bringing the tobacco material into contact with a water vapor stream at 100 to 160° C., and drying the tobacco material by bringing the wetted swelled tobacco material into contact with a superheated water vapor stream at a temperature higher than that of the water vapor.

1 . A tobacco material expansion method comprising the steps of:
 wetting and swelling a tobacco material by bringing the tobacco material into contact with a water vapor stream at 100 to 160° C.; and   drying the wetted swelled tobacco material by bringing the tobacco material into contact with a superheated water vapor stream at a temperature higher than that of the water vapor.   
     
     
         2 . The tobacco material expansion method according to  claim 1 , wherein the tobacco material before contacting the water vapor stream is humidified to 15 to 50 wt %. 
     
     
         3 . The tobacco material expansion method according to  claim 1 , wherein the wetted swelled tobacco material has a water content equal to or higher by not more than 5 wt % than that of the tobacco material before contacting the water vapor stream. 
     
     
         4 . The tobacco material expansion method according to  claim 1 , wherein the step of wetting and swelling is performed by rotating the tobacco material together with the water vapor stream. 
     
     
         5 . The tobacco material expansion method according to  claim 4 , wherein a residence time during the rotation is 0.5 to 5 s. 
     
     
         6 . The tobacco material expansion method according to  claim 1 , wherein the tobacco material is re-humidified after the step of drying. 
     
     
         7 . The tobacco material expansion method according to  claim 6 , wherein the re-humidification is performed by spraying water against the tobacco material. 
     
     
         8 . The tobacco material expansion method according to  claim 6 , wherein the re-humidification is executed on the tobacco material having a water content reduced to not more than 10 wt % in the drying. 
     
     
         9 . The tobacco material expansion method according to  claim 1 , wherein the tobacco material comprises cut midribs. 
     
     
         10 . A tobacco material expansion apparatus comprising:
 a first cyclone including an inlet, an exhaust port, and an outlet;   a first supply-side duct connected to the inlet of the first cyclone;   a first exhaust-side duct connected to the exhaust port of the first cyclone;   a first water vapor supply unit connected to the first supply-side duct;   a first tobacco material supply unit connected to the first supply-side duct positioned between a connecting portion of the first water vapor supply unit and the inlet of the first cyclone;   a second cyclone including an inlet, an exhaust port, and an outlet;   a second supply-side duct connected to the inlet of the second cyclone;   a second exhaust-side duct connected to the exhaust port of the second cyclone;   a heating member placed in the second supply-side duct;   a second water vapor supply unit connected to the second supply-side duct positioned downstream of the heating member;   a second tobacco material supply unit connected to the second supply-side duct positioned between the inlet of the second cyclone and the heating member; and   a conveyor member configured to convey the tobacco material discharged from the outlet of the first cyclone to the second tobacco material supply unit.   
     
     
         11 . The tobacco material expansion apparatus according to  claim 10 , wherein a first circulation duct is formed by connecting the first supply-side duct and first exhaust-side duct connected to the first cyclone, a second circulation duct is formed by connecting the second supply-side duct and second exhaust-side duct connected to the second cyclone, and the first circulation duct positioned near the exhaust port of the first cyclone and the second circulation duct positioned near the exhaust port of the second cyclone are connected by a connection duct. 
     
     
         12 . The tobacco material expansion method according to  claim 2 , wherein the tobacco material comprises cut midribs. 
     
     
         13 . The tobacco material expansion method according to  claim 3 , wherein the tobacco material comprises cut midribs. 
     
     
         14 . The tobacco material expansion method according to  claim 4 , wherein the tobacco material comprises cut midribs. 
     
     
         15 . The tobacco material expansion method according to  claim 5 , wherein the tobacco material comprises cut midribs. 
     
     
         16 . The tobacco material expansion method according to  claim 6 , wherein the tobacco material comprises cut midribs. 
     
     
         17 . The tobacco material expansion method according to  claim 7 , wherein the tobacco material comprises cut midribs. 
     
     
         18 . The tobacco material expansion method according to  claim 8 , wherein the tobacco material comprises cut midribs.