ABSTRACT
Linear and in-duct burners were used for many years to heat air in drying operations before their general use in cogeneration systems. Some of the earliest systems premixed fuel and air in an often complicated configuration that fired into a recirculating process air stream. The first uses in high temperature, depleted oxygen streams downstream of gas turbines in the early 1960s provided additional steam for process use in industrial applications and for electrical peaking plants operating steam turbines. As gas turbines have become larger and more efficient, duct burner supplemental heat input has increased correspondingly.
