Paper Machine Control

With Emerson's DeltaV™ distributed control system (DCS) we can implement an adavnced paper machine control strategy that stabilizes the sheet machine direction basis weight and air dry content by employing a model-based, multivariable control strategy. The model is based on machine speed, thick stock flow, headbox pressure or level, and dryer pressure and can easily be extended to include disturbances such as broke addition.

Features:

• Maximizing production is inherently included, so that the system will automatically default to air dry control over basis weight control if the process is dryer limited
• Fully automated production ramping is included
• Disturbance rejection is a key part of the system
• Intelligent use of scanner data is built into the system
• Flexible use of smart instrumentation is part of the design
• Model deadtime varies based on the production rate, so that as the machine slows down, the feedback slows
• Model predictive and expert system logic for decision-making provides flexibility and the ability to respond effectively to the widest possible variety of real-time conditions