1.Carbon steel used. 2.compared the rotary dryer, whose products' color more fresh and the moisture of the good keeping ... Production Description Carbon steel used.compared the rotary dryer, whose products' color more fresh and the moisture of the good keeping ... dust, biogases, wood chips, rice husk, coffee husk, coir pith, jute sticks, groundnut shells, Bamboo , wood , straw dust, Mustard stalk and ...