Premix burner for furnace with gas enrichment

摘要

An improved premixed gaseous fuel burner (10) for a metal processing furnace includes an axially adjustable gas supply tube (26) concentrically positioned within the burner body (22) for delivering a flow of oxidant or other gaseous fuel component (16) to the combustion chamber (28) of the furnace. Axial repositioning of the air tube controls the spread of oxidant at the core of the flame, thereby controlling flame temperature and the operating environment of the combustion chamber (28) and furnace. A flow mixer (46) having a pair of helically arranged vanes (48) provided in the annular space (20) between the supply tube (16) and the burner body imparts turbulent swirl (A) to the premixture flow to cause enhanced mixing of the premixture. The gas supply tube (26) is externally adjustable and includes a peep sight (34) for externally viewing the flame in the furnace.