| 摘要 |
A concentric burner comprising an inner burner and an outer burner surrounding the inner burner, with a slit flame hole (26), which is for ignition and the radial outward end part (26a) of which extends radially outward from the inner circumferential side and opens at the outer circumferential surface of the outer circumferential peripheral wall part (23a) of the outer burner cap, being opened on the upper wall part (23c) of the outer burner cap (23), wherein the ignition performance is improved by increasing the flow volume of the air-fuel mixture emitted from the outward end part of the slit flame hole. The central part of the slit flame hole (26) is formed in a groove-type flame hole part (26b) the lower surface of which is blocked off. Preferably, a protrusion (27) into which the groove-type flame hole part (26b) penetrates is formed in the lower surface of the upper wall part (23c) of the outer burner cap (23), and a recessed part (28), which receives the outer end part of the protrusion (27) with clearance remaining, is formed in the inner circumferential surface of the outer circumferential peripheral wall part (23a) of the outer burner cap (23), and the radial outward end part (26a) of the slit flame hole (26) is formed so as to communicate with the recessed part (28). |
