An Experimental Study on Residence Time of Tobacco Particles in Rotary Dryers

Rotary dryer has been widely used because of its strong adaptability to various materials, easy operation and reliability. The mean residence time (MRT) of the particles for particle transportation in the rotary drum is important. Due to the limitation of the early reports, the influences of operational and structural parameters on the particle hold-up and MRT of tobacco particles in rotary dryers are presented on an experimental rotary drum in this paper. The influences of rotation velocity, drum slop, gas flow rate, and material flow rate were discussed. Experimental results show that MRT is proportional to particle hold-up, and the increases of rotation velocity, gas flow rate and drum slope reduce MRT and MRT increases with the increasing of material feed rate if other variables are fixed. The results could give good predictions over the range of parameters considered for rotary dryers used in the tobacco industry.