| 摘要 |
PURPOSE:To obtain a large-sized quartz glass block having a required shape with one step by depositing and melting quartz glass in a vessel having the prescribed dimension and shape in the case of producing synthetic quartz glass by hydrolysis of silicon halide under high temp. CONSTITUTION:A synthetic quartz block is formed by hydrolyzing silicon halide (preferably SiCl4) under high temp. to generate fine silica and depositing it on/into a base body and simultaneously melting and vitrifying it with its sensible heat. In this case, the base body having the prescribed dimension and shape is used as a starting member and the large-sized quartz block having the required dimension and shape is obtained by melting and depositing quartz glass on the base body. The temp. of the melted and deposited face of quartz glass is regulated to about 1,800-1,950 deg.C. As the above-mentioned base body, it consists of an outer structural body 13 and an inner structural body 12 and also this inner structural body 12 is preferably divided into four or more pieces. Furthermore a gap having >=5mm width is provided between the inner structural body 12 and the outer structural body 13 and inactive fine particles (e.g. SiC) 14 are packed in this gap and thereby the thermal expansion difference of quartz and the material of the vessel can be absorbed. |
