| 摘要 |
<p>PROBLEM TO BE SOLVED: To inexpensively provide a high quality gypsum by measuring a free water content of a gypsum obtained by dehydrating a waste water after the desulfurization of a waste gas from a lime-gypsum system flue gas desulfurizer and returning it to a gas absorption system for regeneration when the stuck water content is equal to or above a certain value. SOLUTION: The untreated waste gas is introduced to the gas inlet 1-1 of an absorbing tower 1 of the lime-gypsum system flue gas desulfurizer and desulfurized by bring it into contact with a lime slurry sprayed from a spraying device 1-2 arranged at the top of the absorbing tower 1. The lime slurry subjected to the desulfurization treatment is stored in a secondary liquid absorbent tank 3, is subjected to aeration treatment with a compressed air jetted from an air jetting device 3-1 for diffusing oxidation, is supplied to a clarifier 5 through a primary liquid absorbent tank 2 and a waste liquid absorbent tank 4 to be concentrated and is dehydrated by a centrifugal separator 6 to obtain the gypsum. The free water content of the gypsum is measured with a moisture meters 7-1, 7-2 provided on a belt conveyer 8 and compared with a reference value by a water content comparing device 12 and the gypsum having a value equal to or above the reference value is returned to the liquid absorbent tank 2 through a tank 9.</p> |
