Method and apparatus for separating tobacco mixture into lighter and heavier fractions

Apparatus for separating a tobacco mixture comprising a lighter and a heavier fraction into the respective fractions thereof, said apparatus comprising:

• a housing, including a pair of opposed generally upright walls;
• means for introducing the tobacco mixture through one said wall into said housing;
• means for feeding an airstream flow through the other said wall and upward into said housing at the bottom thereof, through the region into which the tobacco mixture is introduced, at a velocity and flow rate sufficient to entrain the lighter fraction of the tobacco mixture but insufficient to retain the heavier fraction, allowing the heavier fraction to fall toward the bottom of said housing carrying some of the lighter fraction with it;
• means disposed in said housing for causing the falling heavier fraction to be traversed by the same airstream flow a second time for separating from the heavier fraction any of the lighter fraction carried down by the heavier fraction;
• means for maintaining a suction lift in the upper portion of said housing to increase the velocity of the airstream flow therethrough;
• a separator unit;
• means for conveying the airstream flow from said housing to said separator unit;
• and
• means for collecting the heavier fraction in said housing.

Apparatus for separating a tobacco mixture comprising a lighter and a heavier fraction into the respective fractions thereof, said apparatus comprising:

• a housing, including a pair of opposed generally upright walls;
• means for introducing the tobacco mixture through one said wall into said housing;
• means for feeding an airstream flow through the other said wall and upward into said housing at the bottom thereof, through the region into which the tobacco mixture is introduced, at a velocity and flow rate sufficient to entrain the lighter fraction of the tobacco mixture but insufficient to retain the heavier fraction, allowing the heavier fraction to fall toward the bottom of said housing carrying some of the lighter fraction with it;
• means disposed in said housing for causing the falling heavier fraction to be traversed by the airstream flow a second time for separating from the heavier fraction any of the lighter fraction carried down by the heavier fraction;
• means for maintaining a suction lift in the upper portion of said housing to increase the velocity of the airstream flow therethrough;
• a separator unit;
• means for conveying the airstream flow from said housing to said separator unit;
• and
• means for collecting the heavier fraction in said housing;
• said means for introducing the tobacco mixture into said housing comprising a torus ripper fan unit having a suction entry for receiving the tobacco mixture, and having a discharge and an injection duct connecting said rotary fan unit discharge to said one wall.

Apparatus for separating a tobacco mixture comprising a lighter and a heavier fraction into the respective fractions thereof, said apparatus comprising:

• a housing, including a pair of opposed generally upright walls;
• means for introducing the tobacco mixture through one said wall into said housing;
• means for feeding an airstream flow through the other said wall and upward into said housing at the bottom thereof, through the region into which the tobacco mixture is introduced, at a velocity and flow rate sufficient to entrain the lighter fraction of the tobacco mixture but insufficient to retain the heavier fraction, allowing the heavier fraction to fall toward the bottom of said housing carrying some of the lighter fraction with it;
• directing means disposed in said housing for causing the falling heavier fraction to be traversed by the airstream flow a second time for separating from the heavier fraction any of the lighter fraction carried down by the heavier fraction;
• means for maintaining a suction lift in the upper portion of said housing to increase the velocity of the airstream flow therethrough;
• a separator unit;
• means for conveying the airstream flow from said housing to said separator unit;
• and
• means for collecting the heavier fraction in said housing;
• said means for introducing the tobacco mixture into said housing comprising a rotary fan unit having a suction entry for receiving the tobacco mixture, and having a discharge and an injection duct connecting said rotary fan
• said directing means comprising sawtooth means disposed in said housing and on said other wall for receiving downward flow of the heavier tobacco fraction and directing that flow toward the bottom of said housing.