Evap Advanced Control for the Evaporator/Concentrator Process   Objectives       Reduce Process Variation Minimize Solids Variation Coordinate Load Change Provide consistent operation from shift to shift

The Evaporator/Concentrator System developed by Automation Applications Inc, LLC (AAI) maximizes the throughput and efficiency of the Evaporator/Concentrator process in pulp manufacturing operations. Using the hardware and software tools found in a modern Distributed Control System, and the instrumentation typical of an Evaporator Set, the system provides the automatic functionality necessary to reduce process variation and significantly improve evaporator control.

• Automatic Evaporator/Concentrator Start-Up
• Control Based on Energy Balance Model
• Coordinated Load Change (Single Knob Control)
• Automatic Vessel Boilout (Valving Must be in Place)
• Inlet and Outlet Liquor Sweetening Capability
• Complete Process Data Monitoring, Trending, and Historical Logging
• Protection Against Vessel Baking

AAI's Evap system can be installed on new Evaporator Sets and as a retrofit to existing Evaporator/Concentrator Processes. In cases where an existing control scheme has been replaced, pulp mill owners have typically realized the following improvement:

• Improved Unit Stability Over Wide Operating Range
• 1-2% Thermal Efficiency Increase
• Minimized Fouling
• ±1% Liquor Solids Control
• Reduced Water Load on Recovery Boiler
• Full Automatic Control 95% of the Time or Greater
• Complete Operator Acceptance of Control System

AAI believes that competitive advantage can be gained by Pulp and Paper Industry Manufacturers through the proper application and use of today's computer and control equipment. This is proven every day by AAI engineers who leverage their technical systems knowledge with process experience to provide clients with significant dollar savings through higher process throughputs and efficiencies. The AAI Evap system is a specific example of this.

AAI optimizes the Evaporator Process using a model which balances thermal load and Btu supply to provide a 'sweet spot' in the center of the Evaporator Set. Instability in the 'sweet spot' results in a wave effect that cycles through the system and affects both evaporator levels and final solids output. The Evaporator/Concentrator System maximizes operating throughput while minimizing unit fouling.