| 摘要 |
<p>PROBLEM TO BE SOLVED: To stably produce caustic soda of target concentration without raising the temperature in a caustic soda tank. SOLUTION: A dilution control device for caustic soda is provided with a first integrating meter 27 which integrates flow rate signals 17 of high concentration caustic soda from a flow meter 15 for high concentration caustic soda, a second integrating meter 28 which integrates flow rate signals 22 of dilution water, which detect flow rates 13 of dilution water regulated by a control valve 14, a multiplier 19 which provides a flow rate signal 20 of dilution water by multiplying a integrated signal 17a of caustic soda by a coefficient 18, an adjuster 21 which outputs an adjustment signal 24 to the control valve 14 to eliminate a deviation between the signal 20 and an integrated signal 22a of dilution water, a switch 29 which opens the control valve 14 with an opening degree ofα% by an operation 35 for starting dilution, and a timer 32 which controls the control valve 14 by the adjustment signal 24 after passage of a set time.</p> |
