Heating element composition and method for preparing tube fillings of high electrical resistance from fused magnesium oxide for tubular electric heating elements
US4048119A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1976 |
| Grant date | Sep 13, 1977 |
| Priority date | — |
| Expiry date | Jun 1, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01B3/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electrical heating element composition comprising crystals of fused magnesium oxide improved by the inclusion of 0.05 to 5% by weight, based on the weight of said fused magnesium oxide, of an additive composition which has excellent lubricating properties in respect of the magnesium oxide crystals and reacts at 800.degree. to 1050.degree. C with active conductivity centers at the surface of one or more adjacent magnesium oxide crystals; an improvement in the preparation of an electrical heating element wherein a granular fused magnesium oxide composition is subjected to mechanical shaping and calcination which comprises employing as the electrical heating element composition a composition comprising crystals of fused magnesium oxide and 0.05 to 5% by weight, based on the weight of said fused magnesium oxide, of an additive composition which has excellent lubricating properties in respect of the magnesium oxide crystals and reacts at 800.degree. to 1050.degree. C with the active conductivity centers at the surface of one or more adjacent magnesium oxide crystals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.