The fuel burns through the burner to produce high temperature gas. With the help of the hot blast stove with enhanced heat exchange measures, the heat of high-temperature gas is transferred to the heated air, and the temperature of high-temperature gas is reduced to 250 ℃ after heat dissipation and then discharged into the atmosphere. The air to be heated is forced into the hot blast stove through the fan of the selected drum. After heat absorption, the temperature rises to the rated value and is sent out from the hot air outlet. When the hot air temperature reaches the upper limit of the rated temperature, the burner will automatically stop burning or automatically switch to small flame combustion. When the hot air temperature drops to the rated lower limit temperature, the burner will re ignite or turn to high fire combustion, and the heating speed is OK Adjust the opening of the air inlet valve to achieve.