A new industrial drying oven developed by Glenro Inc. has been placed in service to dry solvent-based ink on food packaging film webs. Glenro engineers designed the new drying oven to allow thorough, high-speed processing of the web without damaging the film substrate.

High velocity hot air impingement nozzles inside the process dryer direct a perpendicular stream of air at the web's surface. The high velocity air breaks through the boundary layer of air that surrounds the moving web, which facilitates heat transfer to the product. At the same time, the turbulence created also helps vapors to break away from the product surface, aiding vapor exhaust and further evaporation.

Inside the dryer, the web makes several 90° turns over idler rolls, which allows the product to be exposed to a maximum number of high velocity air impingement nozzles in a comparatively small space. The drying oven measures only 40 inches long by 48 inches wide by 48 inches high. A door on the front facilitates easy product access. The system includes an air circulation blower and complete supply and return ductwork. An electric duct heater supplies heat for the oven.

Glenro augments the high velocity air impingement heating with one six-tube quartz infrared heater at the product entrance end of the dryer. The company's laboratory research (and extensive installations in the field) have shown that the strategic addition of infrared heat in a hot air dryer can "kick off" the drying process and allow far faster web processing speeds without sacrifices in product quality.

Power controls and operator interface components for the drying oven are built into a NEMA 12 enclosure, which includes a ventilation blower, wire ways, and number coding of leads.