초록 ▼

The invention features methods and apparatus for obtaining silicon carbide whiskers on a continuous basis. Rice hulls or other carbon and silicon containing feed materials are continuously fed to a conversion zone in an unagitated state in order to promote whisker growth. The conversion zone is cont

The invention features methods and apparatus for obtaining silicon carbide whiskers on a continuous basis. Rice hulls or other carbon and silicon containing feed materials are continuously fed to a conversion zone in an unagitated state in order to promote whisker growth. The conversion zone is continuously purged, preferably with an inert gas such as nitrogen. The purging gas is vented directly out of the conversion zone and carries away gaseous reaction products and impurities, prevents oxidation of the whiskers and keeps glasses from condensing and depositing on the furnace surfaces. The feed materials are fed in a dry state to the conversion zone in order to prevent erosion of the furnace walls. After conversion and cooling the whiskers are separated from the mass of particulate silicon carbide. The whiskers find use as reinforcements.

대표청구항 ▼

A method of obtaining silicon carbide whiskers on a substantially continuous basis from feed materials comprising carbon and silicon, comprising the steps of: (a) substantially continuously feeding to a dehydrating zone materials comprising carbon and silicon and producing dehydrated materials which

A method of obtaining silicon carbide whiskers on a substantially continuous basis from feed materials comprising carbon and silicon, comprising the steps of: (a) substantially continuously feeding to a dehydrating zone materials comprising carbon and silicon and producing dehydrated materials which have a water content by weight of less than approximately one percent of the total composition of said materials; (b) substantially continuously feeding the dehydrated materials formed in step (a) to a conversion zone; (c) substantially continuously passing said dehydrated materials in an unagitated state through said conversion zone at temperatures of above approximately 1000°C. for a time sufficient for a portion of said materials to react to form silicon carbide whiskers; (d) substantially continuously purging said conversion zone of gaseous reaction products; and (e) exhausting said gaseous reaction products directly from said conversion zone before said products deposit on the interior surfaces of said zone or any adjacent processing zones.