| 摘要 |
PURPOSE:To improve high temperature strength, by a method wherein a double cylinder, disposed in a heating furnace, is formed by silicone nitride ceramic. CONSTITUTION:In an outer cylinder 3 and an inner cylinder 4 of a single end type radiant tube burner 2 are formed by silicone nitride ceramic. Bending strength is increased about 2 times as high as that of a cylinder formed by silicon carbide ceramic, and the coefficient of thermal expansion is about 0.75 of that of a cylinder formed by silicone carbide ceramic. Thereby, deformation due to external stress or under its own weight and thermal deformation can be reduced, and when the outer cylinder 5 is disposed in a condition that both ends are secured, durability can be improved. Further, since thermal conductivity is increases about 1.8 time as high as that of a product formed by silicon carbide ceramic, temperature distribution of the outer cylinder 3 can be uniformized. A combustion heat is radiated from the outer cylinder 3 to the outside, and this enables improvement of thermal efficiency prevailing during heating of an object to be heated in a heating furnace 1. |
