| 摘要 |
PURPOSE:To prevent occurrence of flash back by such a structure that a fan is made to be small by providing flame holes and air holes in an angled convex- concave pattern and shortening the length between the air holes opposing to each other and mixture passages and air passages are arranged alternately in a unit integrally molded of a material of high conductivity. CONSTITUTION:A combustion part is constituted by an plurality of units each having an angled convex-concave pattern. The air holes are formed on the both sides of the convex part of the pattern, with the length between the opposing secondary air holes 10 being shortened in the length l, and the flame holes 9 are arranged in the concave surfaces between the convex parts. The mixture passages are provided, each having a mixture gas passage 6, a mixture gas box 7 and a flame hole 9, and the air passages are also provided, each having a secondary air supply port 13, a secondary air supply pipe 5, and an air hole 10. Shortly before reaching the flame holes and air holes 10, both passages are constituted by the unit integrally molded of the material of a high conductivity, with the length few times as long as the depth of the flame hole. By this, the fan can be made to be as small as possible and the occurrence of flash backs can be prevented. |
