Closed loop operation of power plant equipment can result in concentration of selected ions. In order to illustrate the concentration phenomina that occurs in closed loop operation, an analogy is being made to a flue gas desulfurization system in this paper. The information presented in this paper was obtained on the closed loop operation of a flue gas desulfurization (FGD) system is described with all streams In and out of the closed loop defined and monitored. The composition of the coal remained uniform during the test period of 60 days. The water balance of the FGD system was maintained clcsed loop during the test period. Closed loop FGD operation means the only water leaving the FGD system is through evaporation in the cooling and saturating of. The flue gas and the loss of water in the solids which are removed from the FGD system.
Keywords: Closed-loop operation, flue gas desulfurization, water balance, chlorides, fluorides, sulfate, sulfite