Dryer head heat losses

A study was made of heat losses from both insulated and uninsulated dryer heads. To determine head losses, convective heat transfer coefficients were measured on a 5-ft (1.5-m) test dryer at speeds from 500 to 4000 ft/min (152-1220 m/min). These empirical data were then utilized to predict head losses as a function of pressure, speed, diameter, and ambient temperature. The analytical results indicate that insulating the dryer heads substantially reduces heat losses. However, determining net gain in energy savings requires a careful analysis of the overall system. A reduction in dryer head losses may result in a corresponding increase in hood energy usage.