Abstract: The coarse coal powder separator of the coal supply system of Hunjiang power plant boiler No.3 was modified improve the separating efficiency and reduce the flow resistance. The modification was summarized as: at the upper part, 36 slices of barriers were added in stead of original radial barriers; at the lower part, two rows of inertial separating plank (8 slices per row) were added.The gas-solid two-phase flow simulation by means of CFD software FLUENT6.0 was performed for original construction and modified one. The flow field, the powder volume fraction distribution and the pressure field were simulated. Numerical simulation was verified by in-situ test data and the results show that the separator construction modification is successful: the separating efficiency increases by more than 20%,the flow resistance reduces by about 500 Pa.Taking the No.3 boiler as an example, if the boiler works 6000h per year, the electricity of 1.8 million kW·h can be saved,that is equivalent to 450000 RMB.

Key words: coarse coal power separator, gas-solid two-phase flow, separating efficiency, flow resistance