Patent ID: 7045737

Claim:
A glass-processing method incorporating the heating of a glass body by using a thermal plasma torch that comprises: (a) a main body provided with a plurality of ports from which a gas issues; and (b) a device for applying a high-frequency electric field to the gas fed into the main body; the method comprising the steps of: (1) adjusting the size of a plasma flame produced by the torch perpendicular to the center axis of the main body of the torch by controlling the flow rate of the gas fed into each of the ports in accordance with at least one of (1a) the size of the glass body and (1b) the processing condition; and (2) heating the glass body, wherein: (a) a gas to be transformed into a plasma is fed into a port or ports positioned at the inner portion of the arrangement of the ports: (b) a gas to be used as a sealing gas is fed into a port or ports positioned at the outer portion of the arrangement of the ports, and (c) in the step of adjusting the size of a plasma flame, the size is adjusted by varying the flow rate between the gas to be transformed into a plasma and the gas to be used as a sealing gas.