JPH0139009B

PURPOSE:To enable automatic control of a quantity of oxygen supplied, by a method wherein the number of revolutions of an internal-combustion engine for driving a suction pump is regulated so that a value detected by an oxygen concentration detector is equalized to a value determined corresponding to a combustion load. CONSTITUTION:Air, oxygen-enriched by an oxygen enriching air generating means 6 having an oxygen selection permeating film 5, is sucked by a suction pump 7, and it is further boosted by a blower 8 to feed it to a burner 2. An internal-combustion engine 9, for example, gas engine, is coupled to a rotary shaft 7a of the suction pump 7. A value detected by an oxygen concentration detector 14 is provided to a controlling means 16. In the controlling means 16, an oxygen concentration previously determined corresponding to the combustion load of the burner 2 is stored, and the controlling means 16 controls the number of revolutions of the engine 9 so that the value detected by the oxygen concentration detector 14 is equalized to the set value. This enables to obtain a stable burning condition.