Optical fiber drawing furnace

Abstract

The invention relates to an optical fiber drawing furnace comprising a furnace body, a heating element, a heat preservation element, a middle casing pipe, a flow guide pipe, an extension pipe and a furnace top gaseous disc. The optical fiber drawing furnace is characterized by further comprising a lantern ring, an elastic graphite ring and a gas guide disc. The gas guide disc is mounted on the furnace top gaseous disc. The elastic graphite ring is mounted on a hollow ring plate. The lantern ring is arranged between the flow guide pipe and the extension pipe. A plurality of first air inlet holes can be formed in the side wall of the extension tube at the upper end of the lantern ring. The optical fiber drawing furnace has the advantages of being applicable to drawing prefabricated bars in large diameter and optical fiber prefabricated bars with large diameter fluctuation, meanwhile ensuring that graphite dust has less possibility of being adhered to the prefabricated bars, and effectively controlling the air flow state in the drawing furnace.

Description

technical field [0001] The invention relates to a device for optical fiber manufacturing, in particular to an optical fiber drawing furnace suitable for drawing preformed rods with larger diameters and optical fiber preformed rods with larger diameter fluctuations. Background technique [0002] The current optical fiber drawing furnace includes a furnace body, a heating element, an insulating body, a middle casing, a flow guide pipe, an extension pipe, and a furnace top gas tray; the upper and lower walls of the furnace body respectively have an upper drawing hole and a lower drawing hole. The middle casing is installed in the furnace body through the upper drawing hole and the drawing hole, the heat preservation body is arranged in the furnace body, the heating element is arranged in the furnace body between the middle casing pipe and the heat preservation body, and the top gas pan is arranged on the upper drawing hole , one end of the extension tube is connected to the fur...

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Problems solved by technology

There is also the design of directly sealing the preform rod and the wire drawing furnace mouth through the graphite soft felt; the invention patent 200810134932.x discloses a graphite sheet sealing structure of two sealing units, which is sealed by the elasticity of the specially designed graphite sheet However, in these designs, since the drawing furnace adopts a downward airflow direction, the sealing material used at the furnace mouth is under the action of high temperature and friction, causing some graphite soft felt carbon powder to enter the drawing furnace, which will cause the strength of the optical fiber to decrease; In the structure of the two-unit graphite sheet seal in the invention patent 200810134932.x, the elasticity of the graphite sheet is very small at high temperature, and for the preform rod with a large diameter change, it will cause air leakage and cause oxidation of the drawing furnace

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