The utility model discloses a
natural convection drying box without a fan, which comprises a box body, a wind collecting cover, a heater and a storage rack, the storage rack is arranged in the box body, the wind collecting cover can be transversely arranged in the box body and is positioned above the storage rack, an
exhaust pipe joint is arranged at the top of the box body, a flexible air
pipe is arranged between the
exhaust pipe joint and the wind collecting cover, and the flexible air
pipe is connected with the heater. A first partition plate and a second partition plate located above the first partition plate are arranged at the bottom of the box body, an air inlet chamber is defined by the bottom face of the first partition plate and the inner wall, below the first partition plate, of the box body, a heating chamber is formed between the first partition plate and the second partition plate, and the heater is arranged in the heating chamber. Through reciprocating transverse movement of the air collecting cover, the path of air flow can be changed, S-shaped ascending air flow is formed, the air collecting cover can make contact with more materials, the uniformity of heating and
drying of the materials is improved, and the
drying time is shortened.