Top air sealing device for optical fiber drawing

Abstract

The invention relates to a top air sealing device for optical fiber drawing. The top air sealing device is characterized by comprising a self-tightening spring, an annular bottom plate, graphite air sealing rings and an upper pressing ring; a high concave opening and a low concave opening are formed in the annular bottom plate from outside to inside in a sequence; a plurality of equant kerfs are arranged at an inner ring opening of each graphite air sealing ring along the circumference direction; a plurality of graphite air sealing rings are overlapped, and then the outer sides of the graphite air sealing rings are arranged on the high concave opening and compressed through the annular bottom plate; the self-tightening spring is arranged at the low concave opening at the lower side of the inner ring opening of each graphite air sealing ring. The top air sealing device for the optical fiber drawing has the advantages of simple structure, high reliability, convenient maintain and low cost.

Description

technical field [0001] The invention relates to a high-temperature gas sealing device, in particular to a furnace top gas sealing device for optical fiber drawing. Background technique [0002] The process of optical fiber manufacturing is to put the quartz preform into the melting furnace and heat it until the quartz softens, then pull out the thin quartz fiber (that is, the optical fiber) from the bottom of the furnace. The melting furnace uses graphite heating elements, and it is necessary to pass protective gas into the furnace ( Usually argon), so that the flow of argon in the furnace will have a great impact on the optical fiber drawn under the furnace, especially the diameter of the optical fiber, so most of the current optical fiber manufacturers use quartz preforms with uniform diameters (Note: after extension , Finishing, also known as fine rod) drawing, its diameter deviation is usually less than 5mm. [0003] With the intensification of competition, each optical...

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Problems solved by technology

However, the disadvantages of this scheme are as follows: complex structure, increased tower height and rod feeding stroke, inconvenient disassembly and assembly of the furnace, expensive helium gas is required for the protective gas in the furnace, etc.

[0006] 2. The quartz wool scheme, the method is to adapt to the change of the outer diameter of the rod, choose soft high-purity quartz wool at the upper furnace mouth and wrap it in the gap to block the gas. This method is simple and practical, but the operation is cumbersome, and the consistency of use and Poor stability

The disadvantages of this scheme are: complex structure and low reliability

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