초록 ▼

A glass melting tank has a melting chamber, a shallow uniflow conditioning chamber, a shallow refining chamber and a riser chamber between the melting chamber and refining chamber. Heat is input to glass in the riser chamber by electrodes located centrally in the riser chamber near the base of the r

A glass melting tank has a melting chamber, a shallow uniflow conditioning chamber, a shallow refining chamber and a riser chamber between the melting chamber and refining chamber. Heat is input to glass in the riser chamber by electrodes located centrally in the riser chamber near the base of the riser chamber. Temperature sensors sense the temperature entering the riser chamber through a throat and near the base of a downstream wall of the riser chamber and the heat input is controlled to produce torroidal flow in the riser chamber.

대표청구항 ▼

A method of forming molten glass in a glass melting tank comprising heating batch material in a melting chamber to produce molten glass, and supplying heat in a riser chamber that is provided downstream of the melting chamber and which riser chamber has walls and a bottom, wherein refining takes pla

A method of forming molten glass in a glass melting tank comprising heating batch material in a melting chamber to produce molten glass, and supplying heat in a riser chamber that is provided downstream of the melting chamber and which riser chamber has walls and a bottom, wherein refining takes place in a refining chamber to reduce impurities and release bubbles, and conditioning then takes place by cooling in a conditioning chamber connected to an outlet from the glass melting tank, which method further comprises: (a) passing the molten glass from the melting chamber through a throat outlet into the bottom of the riser chamber which is provided with an upstream cooling wall adjacent the outlet of the throat to the riser chamber, a downstream cooling wall remote from the melting chamber and facing said upstream cooling wall, and two side walls connecting the bottom, the upstream cooling wall, and the downstream cooling wall; (b) flowing the molten glass through the riser chamber before entering the refining chamber, while inputting heat to the molten glass in the riser chamber, by use of electrodes located in a lower part of the riser chamber in a central zone spaced from said walls of the riser chamber, to raise the temperature of the forward flowing glass leaving the riser chamber to an elevated, maximum, temperature which is greater than the temperature of the forward flowing glass entering the riser chamber and which is suitable for refining; (c) cooling both said upstream and downstream cooling walls of the riser chamber whereby an inhomogeneous temperature distribution is formed in the molten glass and an upward central flow of molten glass from said electrodes is caused in said central zone of the riser chamber, well spaced from said walls of the riser chamber, with a cooler downward outer glass flow adjacent the walls of the riser chamber, so that glass entering the riser chamber through the throat may rise in the central flow together with recirculated glass that has descended in the downward outer glass flow; (d) effecting a first temperature detection of molten glass on the side of said central zone which is adjacent said downstream cooling wall at the bottom of the riser chamber downstream of the central zone, and effecting a second temperature detection of molten glass flowing into the riser chamber from the throat; (e) controlling the heat input from the electrodes in the riser chamber in dependence on both said first and second temperature detections (i) to raise the temperature of the molten glass in the riser chamber to said elevated, maximum, temperature, and (ii) to maintain a molten glass temperature at the bottom of the riser chamber downstream of the said central zone which is above the temperature of molten glass entering the riser chamber through the throat, thereby preventing a build-up of cold molten glass at the bottom of the riser chamber; and (f) passing the molten glass after leaving the riser chamber to the refining chamber and then from the refining chamber to the conditioning chamber, where the molten glass is cooled to a desired thermal condition prior to flowing continuously through the outlet from the glass melting tank.