| 摘要 |
Apparatus for feeding and classifying tobacco wherein a distributor feeds a mixture of lighter and heavier tobacco particles into an intermediate portion of a vertical duct wherein an ascending current of air entrains lighter particles but permits heavier particles to drop by gravity. The upper portion of the duct is closed by the rotor of a suction drum which accumulates lighter particles and transfers them into the upper end of a vertical chute wherein the lighter particles form a column. The material of the column is evacuated at the lower end of the chute and is converted first into a carpet of uniform height and width and thereupon into a narrow tobacco rope or stream. The rate at which the distributor delivers tobacco particles into the duct can be regulated as a function of the height of the column in the chute and/or as a function of density of tobacco particles in the lower part of the column. Furthermore, the height of the column can be regulated as a function of density of tobacco particles in the lower end of the chute and/or the density of tobacco particles in the chute can regulated as a function of the results of measurement of density in the lower region of the column.
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