Abstract: A glass delivery system is disclosed which includes a molybdenum delivery pipe surrounded by molten glass and inductively heated by a water cooled induction heating coil surrounding the molybdenum pipe and spaced apart therefrom by means of refractory material.

Abstract: An apparatus for mixing or homogenizing viscous material is disclosed. Stirrers, comprising multiple vane mixing blades are mounted on a pair of parallel shafts in corresponding spaced apart parallel tiers. Each vane has a working surface inclined relative to the shaft and offset relative to the vanes of an immediately adjacent blade. One shaft is advanced relative to the other so that the vanes intermesh. The inclination of the vanes in one blade is mirrored in sense to the other blade on the adjacent shaft, and the shafts are rotated in opposite sense so that the stirrers in each tier pump the material in the same relative direction when the shafts are so rotated.

Abstract: A glass delivery system is disclosed having a central glass conducting pipe enclosed within a heat exchange structure. Heat shields reflect energy back to the pipe for reducing heat losses from the pipe and heaters are located about the pipe to add heat energy as required. Heaters which may be immersed in surrounding glass, are provided externally of the pipe at connections into and out of the pipe, and a bellows arrangement for accommodating expansion due to thermal cycling is provided in at least one of such connections. In a preferred embodiment, oxidizable refractory metals are used which may be protected from contamination by providing inert or reducing purging atmospheres or vacuum. Heat losses may also be regulated by atmospheric control of the purging atmosphere as well as control of a working fluid for the heat exchange structure. Means may be provided for shielding or insulating refractory components from intense radiation.