| 摘要 |
PURPOSE:To enable sufficient, rapid and clean heating of quartz glass in heating the quartz glass by using microwave, utilizing heat plasma as a preheating means and preheating the quartz glass in a microwave impressed part. CONSTITUTION:A quartz glass tube 2 of a size capable of containing a quartz glass material 5 is inserted into a microwave irradiating part 1 and a plasma forming gas 3 such as Ar is introduced into the glass tube 2. In the operation, when an electrically conductive rod which is made of C or W and has high heat resistance is separately inserted into the microwave irradiating part in the tube 2, microwave irradiation is started and powder is increased, electric discharge is generated at the tip of the electrically conductive rod and the gas 3 is ignited to produce heat plasma 4. In this state, when the quartz glass material 5 to be heated is introduced into the tube 2, the glass material 5 can be preheated to a given temperature by the heat plasma 4. Then when introduction of the gas 3 is stopped and the tube 2 is removed from the irradiating part 1, microwave can be absorbed in the glass material 5, which is heated. |
