A process for the preparation of a pipe made of quartz glass, tubular semi-finished product made of porous quartz glass and the use of the same

摘要

A method of manufacturing a tube made of quartz glass by flame hydrolysis of a silicon-containing starting component, comprising process steps, in which the starting component a is fed to the deposition burners, by means of this sio₂ particles containing produced, the particles, under formation of a soot tube with a porous soot wall with a predetermined radial soot - density profile on a carrier rotating about its longitudinal axis are separated, the soot tube in a chlorine-containing atmosphere, and the treated soot tube is glazed, characterized in that, in an inner region (1) of the soot wall a higher density (4) of at least 25% of the density of quartz glass, in an outer region (3) of the soot wall a lower density, and in any one of the inner region (1) subsequent transition region (2) a to the outer region (3) is set back decreasing density, with the proviso that the transition region (2) via at least 70% of the thickness of the soot wall extends.