Real-Time Bath Ratio Cascade Control in Continuous Digester
What if the Continuous Digester could automatically respond to changes in bagasse feeding and steam flow—without waiting for operator intervention?
We have made this possible by implementing Real-Time Bath Ratio Calculation and Cascade Control in the Digester DCS.
Earlier, variations in bagasse feeding or steam flow could disturb the Bath Ratio and create tighter material conditions inside the digester. Corrective Black Liquor adjustment depended on manual intervention.
Now, the DCS continuously calculates Bath Ratio using Bagasse BD Flow, Plug Screw Consistency, Steam Flow, Black Liquor Flow and Caustic Flow.
The operator sets the desired Bath Ratio Set Point, while the Bath Ratio Controller acts as the Master Controller and automatically adjusts the Black Liquor Flow through cascade control.
A faster response to process fluctuations, smoother bagasse movement and more stable digester feeding—with less operator intervention.
The After-DCS screen demonstrates 230BTH_RTO – Bath Ratio Control operating in AUTO mode, with real-time Bath Ratio and Black Liquor flow control.
Key Benefits
- Automatic Bath Ratio control
- Improved feeding stability
- Reduced operator intervention
- Better digester liquid conditions
- Lower risk of feeding interruptions and production loss