| 摘要 |
PURPOSE:To obtain excellent burning of the titled heater and to prevent the heater from overheating by providing in a frame case a second partitioning plate positioned on the upper side of a partitioning plate and having first, second and third distribution holes. CONSTITUTION:The second partioning plate 11 positioned on the upper side of a partioning plate 6 is provided within the frame case 1, said partitioning plate 11 having a first distribution hole 12 at its center, a plurality of second distribution holes 13 at both sides of the first distribution hole, and a plurality of third distribution holes 14 at both outer sides thereof. Secondary air streams on respective sides led from the blasting chamber to the upper side thereof are divided to be led at their upper sides into first air streams C at the innermost sides, second air streams D at the outer side of the streams C and third air streams E at the outer sides of the streams D. By this organization, a burner group 4 is supplied on its substantially entire surface with secondary air substantially uniformly by the first and second air streams C and D. Hence, turning of the burner group 4 is excellently carried out. Further, since the burner group 4 is air-cooled by the second and third air streams D and E, the frame case 1 can be prevented from being overheated. |
