The WRFL series horizontal hot air furnace is an integrated unit of a mechanical chain grate combustion device and a heat exchanger designed for specific operating conditions. It is specifically designed for use with drying systems, providing a high-purity hot air up to 550℃ and mixed air up to 750℃ as a energy-saving heat source. It features pollution-free heating, stable and adjustable output temperature, and high thermal efficiency (up to 80% or more). The technical specifications of the equipment meet the most advanced domestic standards. It is widely used in industries such as chemicals, grain, medicine, minerals, mining, food, building materials, etc., serving as an ideal heat source for heating, drying, baking, heat setting, heating, greenhouse breeding, and warehouse dehumidification applications. The furnace uses coal and biomass as fuel sources, employs a horizontal layout and mechanized combustion method, reducing labor intensity, improving combustion efficiency, and is uniquely designed for indirect heating with a horizontal plate structure. It boasts simple structure, high heat exchange efficiency, significant energy saving, less dust pollution to the heat exchanger, uniform thermal stress, avoiding dead corners in heat exchange, and long lifespan.