A glass melting furnace and method for introducing batch feed material into a glass melter tank of the glass melting furnace are disclosed. The glass melting furnace comprises the glass melter tank, a feeder tank, and at least one conduit. The glass melter tank defines at least one melter tank inlet, a molten glass outlet, and an exhaust gas outlet, and the feeder tank, which is separate from the glass melter tank, defines a batch feed inlet and a feeder tank outlet. The at least one conduit is in fluid communication with the feeder tank outlet and the melter tank inlet. Moreover, the melter tank inlet is defined below a melt level of a glass melt contained within the glass melter tank and at least partially filling the at least one conduit.

A heating element for use in a system for melting materials during the production of a glass or ceramic material is disclosed. A method for melting materials during the production of a glass or ceramic material is also disclosed. The heating element comprises a first coupling member configured to couple to a first side of the interior of a melt tank; a second coupling member configured to couple to a second side of the interior of the melt tank; and at least one elongate strip extending between the first coupling member and the second coupling member. The at least one elongate strip is integral with the first coupling member and the second coupling member. The heating element is configured such that during a heating operation, current flows between the first coupling member and the second coupling member of the heating element, along the at least one elongate strip to thereby radiate heat to materials located within the interior of the melt tank.

An alkali-free glass of the present invention includes as a glass composition, in terms of mass %, 55% to 70% of SiO.sub.2, 15% to 25% of Al.sub.2O.sub.3, 0% to 1% of B.sub.2O.sub.3, 0% to 0.5% of Li.sub.2O+Na.sub.2O+K.sub.2O, 2% to 6% of MgO, 2% to 8% of CaO, 0% to 4% of SrO, and 6% to 12% of BaO, and has a strain point of more than 720° C.

An alkali-free glass of the present invention includes as a glass composition, in terms of mass %, 55% to 70% of SiO.sub.2, 15% to 25% of Al.sub.2O.sub.3, 0% to 1% of B.sub.2O.sub.3, 0% to 0.5% of Li.sub.2O+Na.sub.2O+K.sub.2O, 2% to 6% of MgO, 2% to 8% of CaO, 0% to 4% of SrO, and 6% to 12% of BaO, and has a strain point of more than 720° C.

An apparatus for transferring molten glass includes a wall including a refractory material and a metal layer provided on an inside of the refractory material, the metal layer coming into contact with the molten glass, and the metal layer being configured to guide the molten glass, the apparatus including a heater including a metal cover protruding to an inside of the wall, the metal cover coming into contact with the molten glass, the heater including a heat generating element electrically insulated from the metal cover, and the heat generating element receiving electric power to radiate heat rays to heat the metal cover from an inside.

A system for melting materials during the production of a glass or ceramic material is disclosed. A method for melting materials during the production of a glass or ceramic material is also disclosed. The system comprises a melt tank having an interior with a width and a length; and an electrode array comprising a plurality of elongate electrodes each extending at least partially across the width of the interior of the melt tank in a direction substantially perpendicular to the length of the interior of the melt tank. Each electrode within the electrode array is spaced apart from an adjacent electrode within the electrode array by from about 5 mm to 100 mm. The electrode array is configured such that during a heating operation, current flows between adjacent electrodes within the electrode array, such that heat is radiated from the electrodes to materials located within the interior of the melt tank.

An alkali-free glass of the present invention includes as a glass composition, in terms of mass %, 55% to 70% of SiO.sub.2, 15% to 25% of Al.sub.2O.sub.3, 0% to 1% of B.sub.2O.sub.3, 0% to 0.5% of Li.sub.2O+Na.sub.2O+K.sub.2O, 2% to 6% of MgO, 2% to 8% of CaO, 0% to 4% of SrO, and 6% to 12% of BaO, and has a strain point of more than 720 C.

A glass fining system, multi-stage vacuum housing, and method are disclosed. The glass fining system includes a multi-stage vacuum housing comprising a first melt receipt tank configured to receive molten material, where the first melt receipt tank is disposed in a first vacuum chamber; a first refining channel configured to flow the molten material from the first melt receipt tank through a second vacuum chamber; a second melt receipt tank configured to receive the molten material from the first refining channel, where the second melt receipt tank is disposed in a third vacuum chamber; and a second refining channel configured to flow the molten material from the second melt receipt tank and through a fourth vacuum chamber; and a glass melter coupled to the multi-stage vacuum housing.

A system for melting materials during the production of a glass or ceramic material is disclosed. A method for melting materials during the production of a glass or ceramic material is also disclosed. The system comprises a melt tank having an interior with a width and a length; and an electrode array comprising a plurality of elongate electrodes each extending at least partially across the width of the interior of the melt tank. Each electrode within the electrode array is spaced apart from an adjacent electrode within the electrode array by from about 5 mm to 100 mm. The electrode array is configured such that during a heating operation, current flows between adjacent electrodes within the electrode array, such that heat is radiated from the electrodes to materials located within the interior of the melt tank.

A glass melting furnace and method for introducing batch feed material into a glass melter tank of the glass melting furnace are disclosed. The glass melting furnace comprises the glass melter tank, a feeder tank, and at least one conduit. The glass melter tank defines at least one melter tank inlet, a molten glass outlet, and an exhaust gas outlet, and the feeder tank, which is separate from the glass melter tank, defines a batch feed inlet and a feeder tank outlet. The at least one conduit is in fluid communication with the feeder tank outlet and the melter tank inlet. Moreover, the melter tank inlet is defined below a melt level of a glass melt contained within the glass melter tank and at least partially filling the at least one conduit.