Abstract: In a previously known method for producing a hollow cylinder made of synthetic quartz glass, a silicon-containing compound is flame-hydrolyzed and SiO2 particles are deposited layer by layer on a rotating support, resulting in the production of an elongate porous soot body (5) having a central internal bore. Said soot body is dehydrated, doped, or vitrified, a process during which the soot body is held in a vertical direction inside a treatment oven by means of a holding device (9) comprising an elongate holding body (1) which protrudes into the internal bore of the soot body and is made of a material having a higher softening temperature than quartz glass. The aim of the invention is to create a method which is based on the previously known method and by means of which the purity of the hollow cylinder is maintained during said heating process while requiring little time and material for aftertreating the internal bore.

Abstract: According to a previously known method for producing a cylindrical quartz glass body having a low OH content, first an elongate, porous soot body is produced on a rotating support by flame-hydrolyzing a silicon-containing compound and removing layers of SiO2 particles, whereupon said soot body is subjected to a dehydration treatment and is vitrified in a vitrification furnace. The aim of the invention is to create a simple method which is based on said method and makes it possible to produce a quartz glass cylinder having a low OH content while evenly distributing the OH concentration without additional technical complexity. Said aim is achieved by subjecting the soot body to a pretreatment in protective gas and/or a vacuum in the vitrification furnace following the dehydration treatment but prior to the vitrification thereof, the soot body being heated to a temperature ranging between 100° C. and 1350° C. in a heating area.