Abstract: | The progress of dust control technologies for thermal power plants accompanying with the successive revisions of emission standards are reviewed in this paper. Electrostatic precipitator (ESP), Bag Filter (BF) and ESP-BF integration (COPAC) are among those technologies adopted for meeting these standards. It is pointed out that to design the ESP with a migration velocity, it is not enough to consider only the dust resistivity and the chemical composition, which would involve a large error. One has to consider the influences of dust mineral composition and other properties such as microstructure, infiltration, adhesion, particle size distribution and apparent density, as well as the coal combustion method, furnace temperature, and combustion atmosphere. It is recommended to use the Specific Collection Area(SCA) of the ESP as an index of the dust precipitability for different fly ashes, produced from different coal combustions. Based on technical and economical comparisons between ESP, BF and COPAC, the following suggestions are made. (1) In case of stable coal supply, the ESP is preferred, when SCA<160m2/(m3·s-1) in order to meet the emission standard; (2) COPAC is preferred, when SCA≥160m2/(m3·s-1) is required with a variety of or changeable coal supplies or in case when it is necessary to obviously improve the existing ESP performance in order to meet the emission standard. COPAC can also collect M10 and PM2.5 fine particulates in the same manner as BF. (3) BF is preferred when SCA≥160m2/(m3·s-1) is required and in case of low sulfur coal, low inlet dust concentration, uniform gas/dust distribution and even air leakage. |