Abstract:

In the #1 absorption tower of a power plant wet flue gas desulfurization (WFGD) system, a large number of slurry overflowed from effluent pit, the gypsum moisture content beyond index and mist eliminator was blocked. Through analysis, the main reasons were the high load of absorption tower, the fast flow rate of the tower, the insufficient oxidation of calcium sulfite, the high slurry density in the absorption tower and the less desulfurization absorption slurry atomization particles. Combined with the ultra-low renovation project of the desulfurization system, some equipment expansion was implemented such as increasing the spray layer and backup swirl, switching to the one-way double-headed nozzle and three-roof ridge efficient demisters, installing the stainless-steel tray and synergistic ring on tower wall. Meanwhile, some improvement measures were put forward, such as controlling the pH value and density of the absorption tower, adding desulfurization synergist, increasing the number of oxidation fan operation and improving the demister cleaning frequency.

Key words: wet flue gas desulfurization (WFGD), slurry overflow, eliminator blockage, ultra-low emissions