Deposition furnace for fused silica glass

Abstract

The invention relates to a deposition furnace for melting quartz glass. The outer wall of the deposition furnace is made of a heat insulation material. The inner wall of the deposition furnace is made of a fire-resistant material. Electric heating devices or a circulating water cooling device is arranged in the middle interlayer. The deposition furnace is a sectional heat insulation type deposition furnace and is divided into four parts, namely, a furnace body top section, a middle section, a furnace body lower-section and a furnace body bottom from top to bottom, wherein the furnace body top section is an arc-shaped top cover part, and the electric heating devices are arranged in the interlayer, the middle section is divided into 2-5 heat insulation sections, the electric heating devices assist in heating, the circulating water cooling device is arranged on the interlayer of the furnace body lower section, and a cover plate is arranged at the furnace body bottom. Flames and raw materials enter the deposition furnace from the top section of the deposition furnace. A deposition matrix conducts rotational motion along the axis of the deposition matrix, and wholly moves downwards in the deposition process. Heat radiation generated by high temperature of the top of the deposition furnace keeps the deposition surface at high temperature, deposition quality can be improved, and the diameter of the quartz glass can be increased. The quartz glass is slowly cooled from top to bottom through the controllable side wall temperature, the shape of the quartz glass can be maintained, the internal structure is uniform, and the quartz glass with the high size and uniformity can be synthesized.

Description

technical field [0001] The invention relates to a quartz glass manufacturing process, in particular to a deposition furnace for melting quartz glass. Background technique [0002] Quartz glass is SiO 2 One-component glass, with its unique structure, has physical and chemical properties that cannot be replaced by other materials, and occupies an irreplaceable position in the high-tech field. [0003] A method for preparing quartz glass using a plasma chemical vapor deposition (PCVD) process is proposed in the prior art. It uses high-frequency plasma as a heat source to directly produce quartz glass. The rotating quartz glass substrate is heated by flames in a deposition furnace, and silicon dioxide particles are deposited on the substrate and melted into quartz glass. The traditional deposition furnace has a furnace body composed of corundum and other refractory materials inside, and an insulation layer composed of insulation materials on the outside. This type of depositi...

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Problems solved by technology

This type of deposition furnace only plays the role of heat preservation, and the heat required for fused silica glass comes from the flame heat source, resulting in a large temperature gradient on the deposition surface, and the prepared quartz glass has a small diameter and poor structural uniformity; at the same time, the temperature of the traditional deposition furnace body Uncontrollable, there is no reasonable temperature gradient from top to bottom in the furnace, and the prepared quartz glass flows during the descent process, resulting in difficult control of the shape, the diameter does not exceed 150mm, and the optical uniformity is greater than 3×10 -5

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