The US-based Glenro Inc’s new high velocity hot air impingement dryer is used to dry a waterbased silicone finish on a spunbonded polyester nonwoven web that is 210 inches wide. The gas-fired dryer system uses high velocity hot air impingement nozzles mounted beneath the product to apply hot air to the web at a right angle. Hot air impingement breaks through the boundary layer of air that surrounds the moving web and transfers heat to the product to vaporise liquids in the coating or finish.
The turbulence created also helps to exhaust vapour from the process, which speeds further drying. Impingement air is exhausted from the dryer through return tubes, which are evenly spaced across the dryer. High velocity hot air impingement is extremely effective in applications where large quantities of water must be removed from a saturated or coated product.
The complete dryer system measures 11.75-ft-long by 21-ft-wide by 11.8-ft-high, including the dryer enclosure, blowers, ductwork and structural steel support frames.