Process for operation of a burner with controlled axial central air mass flow

A process for the operation of a burner, comprising the steps of:

• providing a burner for a heat generator, the burner including a swirl generator for receiving and swirling at least part of a combustion air flow, the swirl generator defining a central burner axis and having an internal space, the swirl generator configured and arranged for tangentially introducing the combustion air flow into the internal space, the internal space defining a cross sectional throughflow area;
• providing means for the introduction of at least one fuel into the combustion air flow, means at a downstream end of the swirl generator for forming an abrupt widening of the cross sectional throughflow area, and an injection device configured and arranged for the introduction of an axial central air flow along the central burner axis, the injection device including an adjustable element configured and arranged for altering a throughflow cross section of the injection device and for the control of the mass flow of the axial central air flow;
• and
• controlling the axial central air mass flow, thereby controlling an axial position of a recirculation zone, in (i) strongly throttling the axial central air mass flow at low burner load, and (ii) weakly throttling or no throttling of the axial central air mass flow at high burner load.