| 摘要 |
In a known method for producing a tube of quartz glass by elongating a hollow cylinder of quartz glass having an outer diameter AD, said cylinder is continuously supplied to a heating zone with a vertically oriented heating tube having an inner diameter d, with the proviso that the diameter ratio d/AD is set to a value ranging from 1.02 to 1.7. The hollow cylinder is softened therein zonewise, and a tubular strand is drawn off from the softened region and shortened to obtain the tube. Starting therefrom, in order to optimize the dimensional stability of the quartz glass tube obtained, it is suggested according to the invention that the heating zone should have a length L which is set such that the ratio L/d is smaller than 0.9.. |
