Application of a Microwave Mass Flow Meter in a Dense Phase Pneumatic Conveying System of Pulverized Coal

A gas-solid bi-phase mass flow rate measurement technology based on microwave transmission is presented to meet the demand of online flow measurement of pulverized coal in gasification plant. Unlike the methods based on capacitance senor, radiometric sensor and microwave reflection principle, the microwave mass flow meter transmitted microwave through the pulverized coal flow and received on the opposite by antennas. The energy of microwave was absorbed by coal particles. The attenuation degree of the microwave indicated the concentration of the pulverized coal flow. Comparative experiments of microwave mass flow meter and a commercial capacitance mass flow meter were conducted in pilot-scale gasification plant. Experimental results demonstrate the microwave mass flow meter has better dynamic performance than the capacitance mass flow meter in tracking transient fluctuations of pulverized coal flow, especially at start and stop sections during conveying procedure.