摘要 |
The system of the invention is used for removal of impurities from shredded tobacco recovered from defective cigarettes, especially activated carbon particles. In a transport zone for a mixture of shredded tobacco, paper and impurities, directly downstream the device (5) for final tearing of the cigarette paper, said zone constituting a turbulent flow zone for the mixture of shredded tobacco, paper and impurities, a separating device (6) is installed which constitutes a first purification zone. The device comprises a grid (6'), a vacuum system (6'') for maintaining turbulent flow of the mixture of shredded tobacco, paper and lightweight impurities, positioned above the grid (6') having a mesh size larger than the size of heavy impurities, and a vacuum system (6''') for receiving heavy impurities. In a second purification zone, a vibrating sieve (10) is built in having a mesh size larger than the size of heavy and lightweight impurities. A vacuum dust removing device (17), constituting a third purification zone, comprises a transport pipe (18) with flow disturbing elements (22), a rotational sieve (19) having a grid of a mesh size suitable for suction of volatile impurities, a flow guide means (23) adjacent the sieve (19) and constituting at the same time a flow disturbing element, and a rotary chamber valve (20) positioned under the sieve (19).
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