Apparatus for producing a glass tube or rod comprises a blowpipe, a heating sleeve, a nozzle for applying a glass stream to the surface of the blowpipe and a number of heating elements

摘要

Apparatus for producing a glass tube or rod comprises a blowpipe (1); a heating sleeve (2); a nozzle for applying a glass stream (4) to the surface of the blowpipe at one end to form a glass film (4.1) at high temperature and at the other end as a dome (4.2) at low temperature; and a number of heating elements (3). The heat stream density and/or the spatial arrangement of the blowpipe and the heating sleeve are selected so that the temperature of the glass film is kept constant on its periphery. Preferred Features: A screen (5) is arranged between the blowpipe and the heating elements.