A large melting furnace suitable for borosilicate glass. Which has a melting area, a reinforcing area, an ascending area and a clarifying area. The melting area and the reinforcing area are separated by a partition wall, and a lower end of the partition wall goes deep below a surface of molten glass but is not in contact with a bottom of the melting furnace, so as to guarantee that the molten glass in the two areas is interconnected. The structures of the melting area and reinforcing area can also improve the problem of boron volatilization of the borosilicate glass caused by flame melting during a melting process. The molten glass flows out from a throat of the reinforcing area, passes through the ascending area and enters the shallower clarifying area.

A heating element for use in a system for melting materials during the production of a glass or ceramic material may include a first coupling member which may couple to a first side of the interior of a melt tank; a second coupling member which may 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. During a heating operation, current may flow 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.

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.