Apparatus for fabricating porous glass preform

摘要: The present invention provides an apparatus for fabricating porous glass preforms, in which any damages of a reaction vessel due to the increase thermal load can be controlled without enlarging vessel. A wall includes plurality rectangular inner metal plates that defines at least apart side walls vessel, adjacent being weld bonded their edges, and frame members having higher stiffness than arranged along each edge region opposite surface fixed by tightening or welding means.