| 摘要 |
PURPOSE:To enlarge a portion making cntact with fuel and to improve a firing efficiency, by a method wherein a ceramic heating body is connected in a condition to protrude from the surface of an electric insulating ceramic center rod to increase a surface area of a heating part. CONSTITUTION:A heating part 102 consists of a ceramic center rod 108 coaxially protruding downward from a lower end of a housing 103 and a ceramic heating body 112 having an appropriate pitch at a surface thereof and being monolithically coupled in a double spiral. The ceramic center rod 108, being of an electric insulating material, is made of chemically stable alumina which is prevented from being oxidated or varying in properties even in a high-temperature high- pressure combustion gas atmosphere. Meanwhile, the ceramic heating material 112 heated by energizing it is made of a material in which titanium carbide is used as a main component and which is sintered after adding alumina thereto and is excellent in not only resistance to heat but also resistance to oxidation. |
