Dynamic Drainage Control
The completely automated and integrated approach to maintaining optimum dewatering and formation.
A typical Dynamic Drainage Control System. This closed-loop system constantly senses any changes in sheet formation and consistency, and then increases or reduces vacuum levels to maintain optimum sheet consistency.
Features/Benefits
- Real-time vacuum control - instant response to process changes, to maintain proper consistency
- "Set-and-forget" vacuum level control - automatically controls sheet/board properties through changing conditions
- Reduced consistency variations - improved sheet quality, reduced wet end web breaks, minimized fabric wear
- Compensates for changes in furnish, refining activity, headbox consistency, and forming zone activity/drainage - maintains forming dry end control and wet end operating flexibility
- Compatible with mill DCS or process sensors - fully integrates dewatering control into the mill-wide papermaking process
- Remote setpoint input/readout - operator convenience and safety
Applications
Linerboard Machines
DDC Process Improvements:
- Better base sheet consistency control - to optimize ply bond
- Prevents base sheet overdrying
- Prevents wet streaks from carrying to the couch
- Proper consistency prevents liner or white top bleed-through
- Better base sheet condition allows top line to drain through
- Changes in furnish, refining, primary headbox consistency and forming zone activity/drainage will not affect consistency at second headbox
Dandy Rolls
DDC Process Improvements:
- Improves formation by accurately maintaining consistency into dandy roll at optimum level (1.8 - 3.5%)
- Minimizes formation variances to provide continuous, optimum consistency to dandy roll
- Maintains consistent dry sheet to couch. Eliminates wet streaks at the couch -and minimizes wet end breaks
- Changes in furnish, refining, primary headbox consistency and forming zone activity/drainage will not affect consistency to dandy roll
- Better consistency control eliminates dandy picking
Top Wire Hybrid Formers
DDC Process Improvements:
- Cures poor formation by accurately maintaining optimum consistency (1.8 - 3.5%) into the top wire unit
- Minimizes MD formation variances by providing continuously controlled consistency into the top wire unit
- Changes in furnish, refining, primary headbox consistency and forming zone activity/drainage will have no effect on consistency into the top wire through the normal range
- Eliminates the tendency for sheet to pick or follow top former wire