Patent ID: 7905112

Claim:
A process of reforming a quartz glass crucible, wherein the quartz glass crucible is reformed by an arc discharge generated by electrodes positioned around a rotational axis and configured to heat an inside surface of the crucible while the crucible is rotated, the process comprising: using an electrode structure having 3 n electrodes with 3-phase alternating electric current, n being equal to or larger than 2, wherein neighboring electrodes are positioned at regular intervals from each other in a ring-like configuration so as to form a stable ring-like arc between the neighboring electrodes, without generating a continuous arc between electrodes facing each other across a central portion of the ring-like configuration; heating the inside surface of the crucible while the crucible is rotated, wherein a diameter of the crucible is 28 inches or more, and a radius r of the ring-like configuration around the rotational axis is at least ¼ of a radius R of an open portion of the crucible, but not greater than R, for at least a fixed time during arc heating, wherein air is passed on an outer face of the crucible at a time of the arc heating to perform air cooling; and removing one of a foreign substance located on the inside surface and a bubble located under the inside surface by arc discharge.