Abstract: A furnace for fining molten glass is provided in which glass flows in a substantially vertical direction prior to exiting the furnace. As it flows vertically, the glass is allowed to cool. This cooling, in turn, allows the glass to be removed from the furnace through a narrow passageway without producing excessive wear of the passageway. Preferably, vertical flow of the molten glass at the exit end of the furnace is produced across the furnace's full width. In this way, the molten glass does not stagnate within the furnace and undesirable scums on the top surface of the glass are avoided. In certain preferred embodiments, the vertical flow is achieved by a trough which has sloped sides and which connects with and extends downward from the bottom surface of the furnace.

Abstract: A furnace for fining molten glass is provided in which glass flows in a substantially vertical direction prior to exiting the furnace. As it flows vertically, the glass is allowed to cool. This cooling, in turn, allows the glass to be removed from the furnace through a narrow passageway without producing excessive wear of the passageway. Preferably, vertical flow of the molten glass at the exit end of the furnace is produced across the furnace's full width. In this way, the molten glass does not stagnate within the furnace and undesirable scums on the top surface of the glass are avoided. In certain preferred embodiments, the vertical flow is achieved by means of a trough which has sloped sides and which connects with and extends downward from the bottom surface of the furnace.

Abstract: A method is set forth for controlling the height of batch material on the surface of a molten bath in a cold-crown or vertical melting furnace by measuring the level of the upper surface of the batch material, the level of the fusion line between the batch and bath, and the effective hydrostatic head of the molten glass and batch material thereon over a predetermined height at such known fusion line level. The thickness of the batch blanket is then determined from the level of the fusion line and the measured level of the top of the batch blanket, and power input and rate of batch distribution are controlled to maintain such desired levels and accordingly a predetermined batch thickness, by continuously monitoring the level of the batch material and the effective hydrostatic head.

Abstract: A glass delivery system is disclosed having a glass conducting pipe enclosed within a refractory structure. The refractory structure is spaced about the pipe and defines a closed space for receiving therein a quantity of the glass. Flow control means is provided for regulating flow through the pipe. Means is further provided for isolating the flow control device from glass in the closed space to thereby avoid a bypass of said flow control device. A method for operating a glass delivery system is also disclosed.

Abstract: A glass delivery system is disclosed having a glass conducting pipe enclosed within a refractory structure. The refractory structure is spaced about the pipe and defines a closed space for receiving therein a quantity of the glass. Heat input devices are located in the closed space for supplying heat to the pipe. The refractory structure may include heat exchange passages for circulation of a first heat exchange fluid therethrough. Means may be included for introducing a second gaseous fluid within the closed space between the refractory structure and the pipe for removing heat given up by the glass and under certain conditions the first fluid may act as an inert atmosphere or purge gas for protecting certain components of the system from deleterious ambience. The first heat exchange fluid removes a relatively greater portion of the heat energy given up by the glass than the second fluid.

Abstract: In an apparatus for conditioning a supply of molten thermoplastic material, preferably glass, a chamber in flow communication with the supply of glass is mounted for rotation about an axis. The chamber has a flow control surface having at least two regions, each uniquely oriented for influencing the flow of the molten glass therealong. In one region the glass experiences delayed flow to enable it to give up heat and in a region downstream of the first, the glass experiences accelerated flow to enable it to counteract changes in viscosity resulting from previous heat loss. The chamber is rotated so that a fresh supply of glass at an elevated temperature is deposited circumferentially on the flow control surface in order to moderate the influence of heat loss as the glass flows through the chamber.