Method for producing rotationally symmetrical quartz glass crucibles

A process for producing a rotationally symmetrical quartz glass crucible, said process comprising:

• creating electric arcs by means of plurality of electrode arrangements each comprising a cathode and one or more anodes, and each heating in a respective healing zone a wall of the quartz glass crucible while said quartz glass crucible is rotated about a rotational axis thereof;
• and
• the heating zones of the electrode arrangements being spaced from each other in relation to a periphery of the quartz glass crucible;
• and
• the heating zones of the electrode arrangements being evenly distributed about the periphery of the quartz glass crucible.

A process for producing a quartz glass crucible, said process comprising:

• rotating the crucible about a rotational axis at a rate of rotation;
• supplying SiO2 particulate material into the crucible while it is being rotated;
• creating electric arcs using a plurality of electrode arrangements, wherein each electrode arrangement has a cathode and one or more anodes, each electrode arrangement heating a wall of the quartz glass crucible in a respective heating zone while said quartz glass crucible is rotated so as to heat the SiO2 particulate material pressed against the wall by centrifugal force from the rotation so as to form a glass surface on said wall, the electrode arrangements being located evenly distributed rotatively about the periphery of the quartz glass crucible;
• the electric arcs being created such that points on the wall are heated at least twice per revolution so as to reduce temperature differences therein.