| 摘要 |
In order to burn a mixture of fuel and combustion air, in the starting phase of combustion, a reduced proportion of combustion air is supplied in order to improve the combustibility of the mixture, the low supply level being held in a pre-scavenging phase and being continued during the ignition phase to the end of a predetermined safety period, after which the supply of combustion air is increased in one or more stages. In the case of a burner (4) provided with a fan (1) suitable for working the method, the proportion of combustion air may be reduced by reducing the speed of the fan motor (1) by means of a switching circuit (2) with a by-passable resistor 11 preferably controlled by a temperature sensor (19). Alternatively a temperature responsive resistor (Fig. 4, not shown) or ionization detector may replace the sensor (15). <IMAGE> |
