Burner arrangement for heater

A burner arrangement for a mobile heater operated with liquid fuel, said arrangement comprising:

• a combustion chamber converting fuel with combustion air in a flaming combustion, said combustion chamber extending along a longitudinal axis in a main flow direction;
• a pre-mixing chamber in which a flame does not form during regular heating operation, arranged upstream of the combustion chamber, formed separate from the combustion chamber and generating a fuel-combustion air-mixture, said pre-mixing chamber including a side wall tapering in the main flow direction;
• a fuel evaporation surface arranged in the pre-mixing chamber and provided by an absorbent material evaporator body being arranged in the pre-mixing chamber;
• a fuel supply supplying liquid fuel to said pre-mixing chamber;
• and
• a first combustion air supply having a swirl body and supplying a combustion air flow into the pre-mixing chamber with a swirl such that the combustion air is guided along the fuel evaporation surface with a tangential flow component, wherein a neck portion is formed at a transition from the pre-mixing chamber to the combustion chamber at which a flow cross-section abruptly widens in the main flow direction.