| 摘要 |
1,084,030. Resistance heating elements. KOKUSAI DENKI KABUSHIKI KAISHA. Nov. 30, 1965 [Dec. 14, 1964], No. 50805/65. Heading H5H. An electric heating device comprises a hollow cylindrical element 1 having an internal coating 2 of a substance with a maximum emissivity in the far infra-red region and an external coating 3 of a substance with a minimum emissivity in the near infra-red region, and a surrounding cylinder 4 having low emissivity and high reflectivity for near infra-red, the element 1 having a slit 6 the two sides of which are provided with means whereby a power source S can be connected thereacross. The coatings 2 and 3 may be of powdered Fe 2 O 3 or Al 2 O 3 respectively, bonded and secured with water glass (Na 2 SiO 3 ). The cylinder 4 may be of aluminium. The device is shown surrounding a billet 5 to be heated. The element 1 may alternatively be a metal ribbon wound into a helix with a gap between adjacent turns forming the slit, and supported by six bars. |
