Rotary feeder (also called star dust discharge valve, rigidity impeller feeder) is mainly composed of machine body, star rotor, side cover etc. material will fall into the impellers inside rotor from the top of inlet. Rotate it in constant velocity with the driving of the motor. Make material convey to the bottom outlet. According to the installation type, rotary feeder is used as discharger of positive pressure conveying system or negative pressure conveying system.Also use as feeder for providing material in conveying system. In all system, sealing system avoids of air leakage and provides material at the same time.