Patent ID: 7866189
Filing Date: 2011-01-11
Classification: C03B

Abstract:
1. A dehydration-sintering furnace for an optical fiber preform comprising: a cylindrical muffle configured to house the optical fiber preform; a heater arranged around a periphery of the muffle and configured to heat the muffle for dehydrating or sintering the optical fiber preform; a pressure fluctuation absorbing apparatus to suppress fluctuations of a gas pressure in the muffle; a duct connected to an upper portion of the muffle, the duct connected between the muffle and the pressure fluctuation absorbing apparatus to allow a gas flow from the muffle to the pressure fluctuation absorbing apparatus or vise versa; an outer pipe coaxially surrounding the duct so as to form a double tube, thereby allowing heat transfer medium to be present between said duct and said outer pipe to heat said duct; and a container configured to house the pressure fluctuation absorbing apparatus, and the container has an inlet and an outlet to supply the heat transfer medium to said container to heat said pressure fluctuation absorbing apparatus, wherein the container and the double tube are configured to maintain vapor in the pressure fluctuation absorbing apparatus and the duct at 100 degrees Celsius or higher, the vapor containing substances produced in the dehydration and sintering process.