| 摘要 |
1384873 Porous refractives SHELL INTERNATIONAL RESEARCH MAATSCHAPPIJ NV 7 Feb 1972 [8 Feb 1971] 4167/71 Heading C1J A porous radiant heater element is obtained by casting a permeable core in a frame type mould from a mixture of one or more grain sizes of a refractory cement and water, air curing, sintering, cooling and then casting at least one lay of a non permeable refractory casing in a mould around the core from a mixture of dense grading of a different refractory, cement and water, air curing, and sintering each such easing layer, and allowing the formed element to cool ZrO 2 , ZrSiO 4 , Al 2 O 3 and alumina silicates are specified. |
