Method and apparatus for making fused quartz and for forming glass tubing.

摘要

A furnace for making glass comprising a first chamber (10) and a hopper (11) for feeding glass making ingredients (12) into the first chamber (10) with a heater (37) for melting the ingredients (12). A second chamber (16) cnnected to a transfer tube (51) leading to the first chamber and including an extruder (17) for extruding the molten glass. An on-off valve (15) in the transfer tube (51) allows sealing between the chambers and the controlling of the individual pressures in each chamber such that vacuum melting can be effected in the first chamber (10) and the pressure in the second chamber (16) regulated to control the extrusion process while batch melts are periodically fed from the first (10) to the second chamber (16).