| 摘要 |
<p>PURPOSE:To maintain pH at a target value in all operating states by installing a computing element which predicts the concn. of the absorbent in a liquid absorbent and can calculate the supply rate of the absorbent at which the pH can be maintained at the target value. CONSTITUTION:The predicted value 12 of the concn. of the absorbent in the liquid absorbent in an absorption column at the present point of time is calculated from the supply rate and withdrawal rate of the absorbent slurry and the absorption rate of the sulfur oxide in the absorption column and a dissolution rate constant 13 of the absorbent is determined in accordance with the sulfur oxide absorption rate and the concn. of the total Ca ions in the liquid absorbent in the absorption column and the predicted value 12 in the computing element 7. Further, the predicted value 14 of the concn. of the absorbent in the absorption column 14 after n-minutes is calculated from the sulfur oxide absorption rate calculated by the predicted load after n-minutes of the prescribed time and the predicted value 14 of the concn. of the absorbent in the absorption column necessary after n-minutes is calculated from the intensity of the hydrogen ions after n-minutes, the sulfur oxide absorption rate in the absorption column, the constant 13 and the concn. of the total Ca ions in the liquid absorbent are calculated in the computing element 11. The supply rate of the absorbent slurry to the absorption column is controlled in accordance with the deviation between the predicted values 14 and 15 in a coefft. device 17.</p> |
