WET TYPE FLUE-GAS DESULFURIZATION APPARATUS AND APPLICATION METHOD OF THE WET TYPE FLUE-GAS DESULFURIZATION APPARATUS

PROBLEM TO BE SOLVED: To provide a wet type flue-gas desulfurization apparatus capable of reducing the consumed amount of a washing liquid and the treated amount of a waste liquid in the washing of a pH meter at an absorption tower in the wet type flue-gas desulfurization apparatus installed in a thermal power station and the like and stably controlling the limestone supply amount, and to provide an application method of the same.SOLUTION: The adhesion of manganese over a specified quantity on the electrode surface of a pH meter is determined when the pH value of an absorption liquid slurry measured by the pH meter at an absorption tower in an exhaust gas desulfurizer using a wet lime stone-gypsum method exceeds a predetermined specific variation range. The pH meter is taken out from the absorption liquid slurry and the electrode of the pH meter is washed with a washing liquid. The pH meter after washing is immersed again in the absorption liquid slurry and the supply amount control of the absorption liquid slurry is performed so that the pH value of the absorption liquid slurry maintains an up-to-date pH value just after washing the electrode of the pH meter. 【課題】火力発電所等に設置する湿式排煙脱硫装置における吸収塔ｐＨ計の洗浄について、洗浄液消費量、廃液処理量の削減と、石灰石供給量の安定制御を図ることができる湿式排煙脱硫装置とその運用方法を提供すること。【解決手段】湿式石灰石-石膏法を利用した排煙脱硫装置における吸収塔ｐＨ計による吸収液スラリのｐＨ測定値が予め決められた所定の変動範囲を超えると、ｐＨ計の電極表面に所定量以上のマンガンが付着したものと判断して、ｐＨ計を吸収液スラリから取り出してｐＨ計の電極を洗浄液で洗浄し、洗浄後のｐＨ計を再び吸収液スラリに浸漬し、吸収液スラリｐＨ値が、ｐＨ計の電極洗浄直後の最新のｐＨ値を維持するように吸収液スラリの供給量制御を行う。【選択図】図１