Automatic moisture control
The ANDRITZ automatic moisture control system controls the moisture by means of steam control valves at the steam blow box, based on scanner moisture profiles in cross direction.
Moisture MD control
- Closed control loop
- Based on dry-end scanner moisture profiles in MD
- Web moisture is controlled by the dryer
- The dryer uses heated air to dry the web. Steam coils heat the air and fans distribute the air to the blow boxes
- The temperature of the heated air is varied
- The moisture in MD of the resulting web can be controlled in this way
Moisture CD control
- Closed control loop
- Based on dry-end scanner moisture profiles in CD
- Moisture controlled by steam control valves at steam blow box
- The steam box is a metal fabrication whose only purpose is to distribute steam as required to a moving web
- The key to maximum process efficiency is to optimize the condensation rate of steam at the point of application
