Inserted into the combustion chamber (8) is a dish (10) whose length (LE) is greater than a quarter of the length (L) of the combustion chamber (8) and whose angle of wrap around the flame (61) is at most 180@. One end (12) of the dish (10) is situated in the region of the flame root (63). In operation, the dish (10) is heated by heat radiation from the flame (61). The dish (10) thus radiates heat uniformly outwards towards the water-cooled wall (81) and likewise towards the flame (61), in particular at the root (63) thereof. Consequently, oil droplets which get into the combustion chamber (8) from the nozzle of the burner (6) evaporate and can burn. The brown to black covering at the burner is unable to arise and the NOx production is considerably lower than in the case of known pot-shaped inserts. <IMAGE>
