Direct baking type energy-saving hot air furnace

The utility model relates to an energy-saving air heating furnace with a direct-fired type, which relates to a furnace used for supplying heating air. Heat loss is little and temperature of flue gas is low; the utility model has high thermal efficiency and convenient manufacture and use; air enters from an upper part and is exhausted from a lower part; the heat is dissipated by a plurality of rows of diffracted circular tubes; the flue gas passes through the tubes and carries out heat exchanging with cooled air entering at the outer wall of the tubes; water is used for cleaning the ash in the radiating tubes. The utility model is widely applicable to fields of desiccation and dehydration of articles, indoor heat supply, cultivation heat supply, etc.