Abstract: In retrofitting project of wet FGD for coalfired power plants, the original stack need to be upgraded for corrosion resistance due to that the GGH will be eliminated. In order to avoid its influence to the operation of main units, it is necessary to construct a temporary stack. In this article, two methods for construction of temporary stack widely used in actual projects were introduced, and the methods can also be used as good reference for similar project.

Key words: wet flue-gas desulphurization, technical reformation project, gas-gas heater (GGH), stack anticorrosion, temporary stack