Dryer Felt System Operations

On conventional paper and board machines, the energy required to dry the sheet to the desired moisture target at the reel is supplied by a series of rotating steam-heated dryer cylinders or cans that are grouped together into drive sections. Each drive section is equipped with one or two dryer felts to hold the sheet tightly against the heated dryer cans. This improves heat transfer to maximize drying, and also helps control cross-machine direction shrinkage and other sheet distortions. This course discusses the importance of dryer felts, how they operate, typical installation steps, felt guiding components, and the safety hazards that are present around dryer felt systems.

•List the main operating requirements for paper and board machine dryer felts •Describe typical dryer can arrangements, felt runs, and locations of single-tiered and double-tiered dryer sections •List the major steps required to install a new dryer felt •Identify which felt seam types are less likely to mark the sheet •Identify and describe typical felt guiding system components •Explain how felts are guided and tensioned •Explain how seams are straightened •Describe common felt contaminants and how they can be removed •Identify safety hazards and safety guidelines related to dryer felt systems