| 摘要 |
<p>PURPOSE:To reduce an amt. of basic aluminum sulfate to be used remarkably, by digitally grasping data on characteristics of a stack gas and operation states of absorption, oxidation, and neutralization steps, using the data and controlling them, and always maintaining stable operation. CONSTITUTION:An aq. soln. of basic aluminum sulfate (b) is delivered from an absorbing tower 1 through a tank 1' for an intermediate pump to an oxidation tower 2, and during the stay in the tank 1' its basicity is analyzed. This value is used as basicity control data; a digital value of a process state value is thus grasped, and it is fed to each calculation formula corresponding to each step to excute calculation. The results including time lag of control and preestimation of variation of the steps are obtained as set values to control air feed rate to the tower 2 and CaCO3 slurry feed rate to a neutralization vessel 3. In addition, a flow rate F of a stack gas (a) entering the tower 1 and its SOx content S are measured in an operator section 7.</p> |
