Hot air heater and method of operating same

摘要

A hot air heater having a burner tube surrounding a combustion area. The combustion gases travel from the burner tube through first and second circumferential and concentric annuluses surrounding the burner tube. Cool ambient air used for heating is blown over the outside surfaces of the annuluses and heat from the combustion gases is transferred to the ambient air used for heating by way of the surfaces of the jackets defining the annuluses.