| 摘要 |
PURPOSE:To exclude removal work of devitrification, by providing a large number of inflammable gas jets in such a distribution state wherein an upper part side becomes coarse and a lower part side becomes dense. CONSTITUTION:A large number of inflammable gas jets 2 is provided on a burner 3 for processing a quartz glass tube, whose distribution is in such a state wherein it is coarse in its upper side part and dense in its lower side part. If a part A of the quartz glass tube which is to be a sealed part and a part B upper than that are heated by the burner 3 provided with the inflammable gas jets 2 at the time of sealing of the edge of the quartze glass tube 5, a temperature at the part B can be increased higher than usual and a cooled part of the quartz glass tube can be prevented from occurring. With this, even if vapour is generated through heating of the quartz glass tube 5, devitrification is not generated on the surface of the quartz glass tube 5 as the vapour is not deposited on not only the part A but also the part B. |
