| 摘要 |
1,164,629. Moulding combustion elements. AMERICAN THERMOCATALYTIC CORP. 25 Nov., 1966 [3 Feb., 1966], No. 52971/66. Heading B5A. [Also in Divisions C7 and F4] A combustion element capable of promoting the substantially flameless infra-red radiation generating combustion of gases flowing therethrough comprises a gas-permeable ceramic mat of amorphous fibres in combination with powdered, metallic aluminium in amount from 20 to 80% by weight of the ceramic material. The mat may be formed on a foraminous support with said fibres of silica-alumina, and alumina also present. The element may be formed in the following manner. A gallon of gel is made using 1À0 grams of colloidal alumina and 78À9 grams of aluminium nitrate-9 hydrate per gallon of water. To form a slurry 8À5 grams of ceramic pre-chopped fibres are then added together with, after a suitable time lapse and agitation, 93À5 grams of methyl methacrylate and 6À5 grams of powdered aluminium. A foraminous support is then inserted in the slurry and connected to a source of vacuum to cause accretion of solids thereon. A layer “ inch thick is accreted and the element then dried for a sufficient time to vaporize all the methyl methacrylate. In a further method of forming the element a layer 0À275 inch thick is accreted on the support from a slurry not containing the powdered aluminium. The element is then dusted with the aluminium powder. The slurry may alternatively be prepared using 120 grams of colloidal alumina, 78À9 grams of Al(NO 3 ) 3 - 9H 2 O, 8À5 grams of fibres and 93.5 grams of methyl methacrylate. To 800 ml. of this was added 0À1% by weight of aluminium. The elements were then formed by accretion of a support. |
