Patent ID: 8590344

Claim:
A method for producing a cylinder of quartz glass, said method comprising: sintering a SiO 2 body that comprises a porous SiO 2 soot layer and has a lower end, an upper end and an outer jacket, said SiO 2 body having an inner bore with an upper end, in a vitrification furnace so as to obtain the quartz glass cylinder; wherein said SiO 2 body is held using a holding device in a vertical orientation, wherein the holding device comprises an upper holding element that engages the upper end of the SiO 2 body in the upper end of the inner bore, and a lower holding element arranged on the lower end of the SiO 2 body; and wherein the holding device comprises dimensionally stable connection members that each extends inside the vitrification furnace along the outer jacket of the SiO 2 body and interconnects the upper holding element and the lower holding element; and, wherein the dimensionally stable connection members are holding rods interconnecting the upper holding element and the lower holding element.