An end-fired melting furnace and a method of melting raw materials by an end-fired melting furnace are provided, where the furnace includes a melting tank, a melting chamber, first and second ports, at least one burner, and at least one auxiliary fuel injector arranged in the end-fired melting furnace in a roof or in first and second side walls so that the at least one auxiliary fuel injector introduces a fraction X2 of auxiliary fuel, in a direction of re-circulating combustion products, without additional oxidiser, into the re-circulating combustion products in a direction of a flow of the re-circulating combustion products, and with a chosen velocity such that the fraction X2 of auxiliary fuel mixes with the re-circulating combustion products before being combusted by oxidiser entering the furnace.

A cover plate structure for a glass fiber tank furnace forehearth includes chest wall bricks at two sides of the forehearth, cover plate bricks each spanning between a top end of at least one of the chest wall bricks at one of the two sides of the forehearth and a top end of at least one of the chest wall bricks at another one of the two sides of the forehearth, a thermal insulation layer covering outer surfaces of the cover plate bricks and the chest wall bricks, and a gap-covering brick fixed between the cover plate bricks and the thermal insulation layer and covering a gap between adjacent ones of the cover plate bricks.

A cover plate structure for a glass fiber tank furnace forehearth includes chest wall bricks at two sides of the forehearth, cover plate bricks each spanning between a top end of at least one of the chest wall bricks at one of the two sides of the forehearth and a top end of at least one of the chest wall bricks at another one of the two sides of the forehearth, a thermal insulation layer covering outer surfaces of the cover plate bricks and the chest wall bricks, and a gap-covering brick fixed between the cover plate bricks and the thermal insulation layer and covering a gap between adjacent ones of the cover plate bricks.

An apparatus and method for producing a glass article includes a melting vessel, a fining vessel located downstream from the melting vessel, and a bubbling vessel that is downstream from the melting vessel and upstream from the fining vessel. The fining vessel may include at least a first zone and a second zone downstream from the first zone, wherein the average temperature of the first zone is higher than the average temperature of the second zone.

An apparatus and method for producing a glass article includes a melting vessel, a fining vessel located downstream from the melting vessel, and a bubbling vessel that is downstream from the melting vessel and upstream from the fining vessel. The fining vessel may include at least a first zone and a second zone downstream from the first zone, wherein the average temperature of the first zone is higher than the average temperature of the second zone.

Disclosed is an apparatus for conditioning molten glass. The apparatus includes a connecting tube assembly having a conduit for conveying the molten glass, the conduit including at least two flanges and a sealing member disposed between the at least two flanges around an outer peripheral region of the flanges, thereby forming an enclosed volume between an outer wall of the conduit, the at least two flanges and the sealing member. An atmosphere within the volume may be controlled such that a predetermined partial pressure of hydrogen or a predetermined partial pressure of oxygen may be maintained within the volume. A current may be established between the at least two flanges to heat the conduit.

Disclosed is an apparatus for conditioning molten glass. The apparatus includes a connecting tube assembly having a conduit for conveying the molten glass, the conduit including at least two flanges and a sealing member disposed between the at least two flanges around an outer peripheral region of the flanges, thereby forming an enclosed volume between an outer wall of the conduit, the at least two flanges and the sealing member. An atmosphere within the volume may be controlled such that a predetermined partial pressure of hydrogen or a predetermined partial pressure of oxygen may be maintained within the volume. A current may be established between the at least two flanges to heat the conduit.

According to the present invention, provided is a heater including a heat generating member being conductive and configured to radiate heat rays by being fed with electric power, a tubular member constituted by a metal and accommodating the heat generating member, and an intermediate member arranged between the heat generating member and the tubular member and constituted by an electrically insulating material, wherein the intermediate member is arranged and/or configured to allow, among the heat rays radiated from the heat generating member, at least light having a wavelength of from 1 m to 2 m to pass through the intermediate member to reach the tubular member.

According to the present invention, provided is a heater including a heat generating member being conductive and configured to radiate heat rays by being fed with electric power, a tubular member constituted by a metal and accommodating the heat generating member, and an intermediate member arranged between the heat generating member and the tubular member and constituted by an electrically insulating material, wherein the intermediate member is arranged and/or configured to allow, among the heat rays radiated from the heat generating member, at least light having a wavelength of from 1 m to 2 m to pass through the intermediate member to reach the tubular member.

A gradient fining tank and a method of operating the tank to refine foamy molten glass is disclosed. The gradient fining tank includes a floor, a roof, and two laterally-spaced sidewalls that at least partially define an interior chamber of the tank. The floor of the tank is profiled to provide the tank with an extended shallow portion that defines an inlet to the interior chamber and a deep holding portion that defines an outlet from the interior chamber. An entry section of the floor provides the extended shallow portion of the tank and a transition section and exit section of the floor provide the deep holding portion. A depth of the interior chamber at an outlet end of the deep holding portion is greater than a depth of the interior chamber at the outlet end of the extended shallow portion.