A method of reducing bubble lifetime on the free surface of a volume of molten glass contained within or flowing through a vessel including a free volume above the free surface, thereby minimizing re-entrainment of the bubbles back into the volume of molten glass and reducing the occurrence of blisters in finished glass products. The method includes vaporizing a volatile material, entraining the vapor in a carrier gas to form an enrichment gas, and flowing the enrichment gas into the free volume to increase a concentration of the volatile material at the surface of the molten glass in the vessel.

A glass composition includes, as main content components, by mass %, a TeO.sub.2 content percentage of 50% to 80%, a Bi.sub.2O.sub.3 content percentage of 0% to 30%, a WO.sub.3 content percentage of 0% to 30%, a ZnO content percentage of 0% to 30%, a BaO content percentage of 0% to 30%, a GeO.sub.2 content percentage of 0% to 30%, and a Ga.sub.2O.sub.3 content percentage of 0% to 30%, wherein at least any one of additive target elements is introduced, the additive target elements including, Si.sup.4+ of 1 mg/kg to 1,500 mg/kg, B.sup.3+ of 1 mg/kg to 1,500 mg/kg, P.sup.5+ of 1 mg/kg to 1,500 mg/kg, Li.sup.+ of 1 mg/kg to 1,500 mg/kg, Na.sup.+ of 1 mg/kg to 1,500 mg/kg, K.sup.+ of 1 mg/kg to 1,500 mg/kg, Mg.sup.2+ of 1 mg/kg to 1,500 mg/kg, Ca.sup.2+ of 1 mg/kg to 1,500 mg/kg, Al.sup.3+ of 1 mg/kg to 1,500 mg/kg, and Sr.sup.2+ of 1 mg/kg to 1,500 mg/kg.

A glass composition includes, as main content components, by mass %, a TeO.sub.2 content percentage of 50% to 80%, a Bi.sub.2O.sub.3 content percentage of 0% to 30%, a WO.sub.3 content percentage of 0% to 30%, a ZnO content percentage of 0% to 30%, a BaO content percentage of 0% to 30%, a GeO.sub.2 content percentage of 0% to 30%, and a Ga.sub.2O.sub.3 content percentage of 0% to 30%, wherein at least any one of additive target elements is introduced, the additive target elements including, Si.sup.4+ of 1 mg/kg to 1,500 mg/kg, B.sup.3+ of 1 mg/kg to 1,500 mg/kg, P.sup.5+ of 1 mg/kg to 1,500 mg/kg, Li.sup.+ of 1 mg/kg to 1,500 mg/kg, Na.sup.+ of 1 mg/kg to 1,500 mg/kg, K.sup.+ of 1 mg/kg to 1,500 mg/kg, Mg.sup.2+ of 1 mg/kg to 1,500 mg/kg, Ca.sup.2+ of 1 mg/kg to 1,500 mg/kg, Al.sup.3+ of 1 mg/kg to 1,500 mg/kg, and Sr.sup.2+ of 1 mg/kg to 1,500 mg/kg.

A glass furnace including a refractory portion defining a hot face in contact or intended to be in contact with molten glass or with a gaseous environment in contact with molten glass, and a cold face at a distance from the hot face, and a temperature measurement device. The temperature measurement device including a waveguide that includes a measurement portion including at least one temperature measurement sensor configured to send a response signal in response to the injection of an interrogation signal into the waveguide. The temperature measurement device including an interrogator connected to an input of the waveguide and configured to inject the interrogation signal into the input, to receive the response signal returned by the sensor in response to the injection of the interrogation signal, to analyze the response signal received and to transmit a message according to the analysis.

A glass furnace including a refractory portion defining a hot face in contact or intended to be in contact with molten glass or with a gaseous environment in contact with molten glass, and a cold face at a distance from the hot face, and a temperature measurement device. The temperature measurement device including a waveguide that includes a measurement portion including at least one temperature measurement sensor configured to send a response signal in response to the injection of an interrogation signal into the waveguide. The temperature measurement device including an interrogator connected to an input of the waveguide and configured to inject the interrogation signal into the input, to receive the response signal returned by the sensor in response to the injection of the interrogation signal, to analyze the response signal received and to transmit a message according to the analysis.

The present invention provides for synthesizing high optical quality multicomponent chalcogenide glasses without refractive index perturbations due to striae, phase separation or crystal formation using a two-zone furnace and multiple fining steps. The top and bottom zones are initially heated to the same temperature, and then a temperature gradient is created between the top zone and the bottom zone. The fining and cooling phase is divided into multiple steps with multiple temperature holds.

The present invention provides for synthesizing high optical quality multicomponent chalcogenide glasses without refractive index perturbations due to striae, phase separation or crystal formation using a two-zone furnace and multiple fining steps. The top and bottom zones are initially heated to the same temperature, and then a temperature gradient is created between the top zone and the bottom zone. The fining and cooling phase is divided into multiple steps with multiple temperature holds.

An apparatus for the production of a mineral melt burns combustible material in the presence of inorganic material to form a melt. The apparatus includes a circulating combustion chamber which receives a fuel, pre-heated mineral material and a combustion gas so as to melt the mineral material and generate exhaust gases which are separated from the melt. The gases pass through an exhaust pipe to a conduit of a heat exchange system. The apparatus includes a quenching hood for quenching the exhaust gases by drafting a cooling fluid, such as ambient air, into the flow of exhaust gases around the exhaust pipe, and wherein the exhaust gases exit the exhaust pipe inside the hood.

An apparatus for the production of a mineral melt burns combustible material in the presence of inorganic material to form a melt. The apparatus includes a circulating combustion chamber which receives a fuel, pre-heated mineral material and a combustion gas so as to melt the mineral material and generate exhaust gases which are separated from the melt. The gases pass through an exhaust pipe to a conduit of a heat exchange system. The apparatus includes a quenching hood for quenching the exhaust gases by drafting a cooling fluid, such as ambient air, into the flow of exhaust gases around the exhaust pipe, and wherein the exhaust gases exit the exhaust pipe inside the hood.

A manufacturing method for a glass article includes a supply step of supplying a glass raw material onto a surface of a molten glass accommodated in a melting chamber of a glass melting furnace from a supply unit mounted to a front wall of the melting chamber, and a melting step of melting the supplied glass raw material through heating with an electrode immersed in the molten glass in the melting chamber. The method also includes an outflow step of causing the molten glass to flow outside the melting chamber from an outflow port provided at a rear wall of the melting chamber, wherein 60% to 95% of an area of the surface of the molten glass in the melting chamber is covered with the glass raw material supplied in the supply step.