Abstract: In 4 650 kW heat medium heater system, the dust accumulated over the external of TL heat exchanger's barbed pipe and internal of flue duct of air preheater will effect on the efficiency of heat exchanger, resulting in raising smoke discharging temperature and declining in heat efficiency. Applying dynamic rotat-able pulse dust blowers to can reduce smoke temperature by 30℃, smoke discharging temperature by 50℃ and average oil consumption by about 4. 55%. The overall purging operation shall be program controlled by PLC programable controller.