Burner for nitrogen-bearing fuels, with coaxial primary air ducts - has furnace gas recirculating ducts to these ducts, pref. entering at restriction

摘要

The burner for nitrogen-bearing fuels is based on one with a central air tube housing one or more fuel pipes, enclosed by another with at its inlet an axially-movable swirler ring and a conically divergent outlet end. One air supply duct feeds both. Around the outlet (8) one or more gas-recirculating ducts (13) are arranged from the furnace (17) to the air duct, pref. discharging into the latter where it has a restriction. If (controllable) secondary-air nozzles (10) are fitted, concentrically around the burner, the recirculating-duct apertures lie outside their pitch circle.