The YLW series thermal oil heater, with its horizontal layout and square coil tube design, uses a chain grate system for efficient fuel combustion. It incorporates mechanical features for solid fuel feeding, ventilation, and slag removal. During operation, fuel undergoes radiation and convection heat exchanges, proceeds to the waste heat boiler, and subsequently moves to the air preheater and dust remover. The remaining flue gas is then expelled into the atmosphere, resulting in optimal heat transfer and efficient industrial heating.