Together, the Yankee dryer and Yankee hoods provide the final drying of a tissue sheet before it is wound up by the reel. Some of the drying energy is provided by steam condensing inside the dryer, and the rest is provided by hot air being blown onto the sheet by the Yankee hoods. This module describes the equipment and processes responsible for supplying dry, heated air to, and removing humid exhaust air, from the Yankee hoods on a typical, modern Yankee dryer.
Learning Objectives
- Describe the design of Yankee hoods
- Describe Yankee hood air system equipment and flows
- Describe cross-machine moisture profiling in Yankee hoods
- Describe supply, recirculation, and exhaust air flows
- Identify heat recovery
- Gas burner modes, permissives, and interlocks
- "Balancing" the hoods