Many of our spray drying plants are supplied with indirect fired air heaters for either light or heavy oil or gas. This air heaters specially designed for spray drying plants in order to ensure the best possible economy and reliability. The HAG has high overall thermal efficiency of 86 ± 1% on gross calorific value (GCV) of fuel oil & 93 ± 1% on net califoric value (NCV) of fuel oil/stack temperature of less than 200oC and compared to electrical heating saves 80% energy