Rotary discharge tube is a gravity discharge or blow-through type valve. It is used when pneumatic conveying system is incorporated in plant. It is suitable for all types of dry bulk materials and handles large quantities of powder. They are composed of valve body, rotor, sealing ring system, bottom bin, automatic grease-feeding device and grease distributor. It is on the bottom of vibro feeder, dry quenching stove and coke outlet. Its rotor is driven by electric power and revolves according to prescriptive direction.