LEVEL CONTROLLING PROCESS OF ABSORPTION TOWER IN STACK GAS DESULPFURIZATION APPARATUS FOR WET SLAKING GYPSUM PRODUCTION

摘要

PURPOSE:To control the level of an absorption tower at a fixed level for the sudden change of a boiler load by inputting the measured signal of the boiler load or fuel flow rate into a function generator and operating a control valve provided in a pipe line for discharging the washing liq. from the absorption tower with the output signal from the function generator and a level controller. CONSTITUTION:The load of a boiler 11 is sensed by a sensor 12 and the signal is fed to the function generator 12 generating a function expressed by the relation between the boiler load and the total amt. of absorbent of the absorption tower and make-up water. An amt. of CaCO3 as the absorbent equivalent to the amt. of absorbed SO2 is fed to the washing liq. in the absorption tower 3 from a pipe 7. The level of the washing liq. in the absorption tower 3 is sensed and fed to a level sensing controller 9. The sensed signal and the output signal from the function generator 12 are added in an adder 14, and a control valve 10 provided to a pipeline 8 for discharging the washing liq. from the absorption tower 3 is operated by the output signal from the adder 14. Thus, the level of the absorption tower is held at an almost fixed level.