Burner

摘要

The invention relates to a gas or multi-purpose burner with a central outlet for core air as a first combustion-air fraction, with an annular second outlet, surrounding the first outlet, for primary air as a second combustion-air fraction, and with an annular third outlet, surrounding the second outlet, for secondary air as a third combustion-air fraction, a first part of the gaseous fuel being capable of being introduced, within the burner, into the primary-air stream and the second remaining part of the gaseous fuel being capable of being introduced into the secondary-air stream, and the supplied quantities of core air and primary air on the one hand and of secondary air on the other hand being adjustable independently of one another, and the adjustment of the air-stream quantities and the division of the fuel quantities taking place in such a way that primary-air/fuel mixture emerging from the second outlet, together with the core air, is sub-stoichiometric and the secondary-air/fuel mixture is super-stoichiometric, and, furthermore, means being provided for sucking up flue gases independently by means of the combustion air. The NOx values can be reduced considerably by means of the specified measures.