Airflow preheating device

An airflow preheating device, comprising a heating pipe and a flow guide pipe, wherein a lower end of the flow guide pipe is provided with an opening and an upper end of the flow guide pipe is closed;

• upper and lower ends of the heating pipe are separately provided with an opening;
• the flow guide pipe is embedded in the heating pipe;
• an outer wall of the flow guide pipe is provided with a flow guide device;
• a lower end wall of the flow guide pipe is provided with an air flow hole;
• a ventilation pipe is provided inside the flow guide pipe;
• the ventilation pipe is a hollow pipe, two ends of which are separately provided with an opening;
• an outer diameter of the ventilation pipe is less than an inner diameter of the flow guide pipe, so as to form an air flow space between an outer wall of the ventilation pipe and an inner wall of the flow guide pipe;
• a maximum outer diameter of the flow guide device on the outer wall of the flow guide pipe is less than or equal to an inner diameter of the heating pipe;
• air enters the ventilation pipe from a lower end;
• an air flow enters an area between the inner wall of the flow guide pipe and the outer wall of the ventilation pipe from a top end of the ventilation pipe, and then enters a space formed between the outer wall of the flow guide pipe and an inner wall of the heating pipe via the air flow hole on the wall of the flow guide pipe, and the flow guide device guides the air flow to flow out from a top end of the flow guide pipe from bottom to top.