This product is a patent product, it integrated the advantages of all kinds of metal furnace is improved, has high thermal efficiency, save fuel (province more than two 5) than all kinds of furnace, long service life, heat up quickly, temperature stability, temperature adjustable, tea, food, no pollution, easy installation, the advantages of simple operation, can be widely used in the tea, melon seeds, peanut, walnut and so on food, Chinese herbal medicine, agricultural and sideline products, paper products, chemicals, timber in areas such as drying, baking operation.