Efficiency of the combustion that is carried out in the forehearth of a glass manufacturing facility is improved by replacing air-fuel burners with a smaller number of air-fuel injectors and oxygen injectors.

Forehearth constructions are described in which means are provided to heat the sides of the stream of molten glass (27) passing along the forehearth from a glass-making furnace to one or more molten glass outlets by way of flames emerging from a series of substantially horizontal slots. The slots are located in the side walls of the channel above the level of the molten glass surface when the forehearth is operating, and the ribbon of flame provides improved heat transfer to the molten glass stream. Burner blocks are disclosed for use in constructing a forehearth of this type, each consisting of a block of refractory material having an internal cavity (3) of generally wedge-shaped construction and having an elongated outlet in. the form of a slot (4) in the face of the block. A combustible gaseous mixture, or the components to form a combustible gaseous mixture, are fed into the cavity remote from the slot.

The invention relates to a method for heating flowable molten glass in a feed channel which is enclosed by lateral walls and a cover and into which a plurality of fuel lances and oxidizing agent lances that are mutually spaced in the flow direction of the molten glass open above the molten glass, fuel or an oxidizing agent being supplied through said lances and being brought into reaction with each other in the feed channel. The invention is characterized in that in order to combust the fuel with the oxidizing agent, a flame is produced in front of the opening of each fuel lance, said flame being designed such that adjacent or opposite flames do not contact one another.

A coaxial fuel and oxygen pipe apparatus can include a fuel pipe and an oxygen pipe, wherein the fuel pipe is contained within the oxygen pipe and the oxygen pipe comprises an internal diameter that is continuous without diameter changes along a length of the oxygen pipe. The fuel pipe can include an internal diameter that is continuous without diameter variations along a length of the fuel pipe. A discharge block includes a diverging section and a discharge that forms a final outlet with respect to the fuel pipe and the oxygen pipe. The discharge block is configured with two angles that can facilitate conditions for eliminating recirculation, wherein the two angles are matched to an expansion rate of the products of combustion to maintain a positive pressure throughout a final discharge from the final outlet.

A coaxial fuel and oxygen pipe apparatus can include a fuel pipe and an oxygen pipe, wherein the fuel pipe is contained within the oxygen pipe and the oxygen pipe comprises an internal diameter that is continuous without diameter changes along a length of the oxygen pipe. The fuel pipe can include an internal diameter that is continuous without diameter variations along a length of the fuel pipe. A discharge block includes a diverging section and a discharge that forms a final outlet with respect to the fuel pipe and the oxygen pipe. The discharge block is configured with two angles that can facilitate conditions for eliminating recirculation, wherein the two angles are matched to an expansion rate of the products of combustion to maintain a positive pressure throughout a final discharge from the final outlet.

A method for heating a liquid glass channel of a glass fiber tank furnace. The method comprises: passing oxygen gas and a fuel, via a burner (1), into a channel space (3) for combustion to heat the channel space (3) and a liquid glass (2), wherein the flow rate of the fuel is V.sub.F and the flow rate of the oxygen gas is V.sub.OX such that the relative velocity difference D=(V.sub.FV.sub.OX)/V.sub.F. The temperature of the channel is 0-1500 C., and the relative velocity difference D is kept to 25% or more. A pure oxygen combustion method is used for heating a tank furnace channel to reduce waste gas emission and heat loss, thereby achieving the goals of energy conservation, reduced carbon emissions, and improve environment friendliness. The fuel flow rate, relative velocity difference, and related parameters can be controlled according to the temperature of the channel, providing excellent uniformity and accurate control of the temperature of the channel.

A method for heating a liquid glass channel of a glass fiber tank furnace. The method comprises: passing oxygen gas and a fuel, via a burner (1), into a channel space (3) for combustion to heat the channel space (3) and a liquid glass (2), wherein the flow rate of the fuel is V.sub.F and the flow rate of the oxygen gas is V.sub.OX such that the relative velocity difference D=(V.sub.FV.sub.OX)V.sub.F. The temperature of the channel is 0-1500 C., and the relative velocity difference D is kept to 25% or more. A pure oxygen combustion method is used for heating a tank furnace channel to reduce waste gas emission and heat loss, thereby achieving the goals of energy conservation, reduced carbon emissions, and improve environment friendliness. The fuel flow rate, relative velocity difference, and related parameters can be controlled according to the temperature of the channel, providing excellent uniformity and accurate control of the temperature of the channel.

A method of forming high strength glass fibers in a refractory-lined glass melter, products made there from and batch compositions suited for use in the method are disclosed. The glass composition for use in the method of the present invention is up to about 64-75 weight percent SiO.sub.2, 16-24 weight percent Al.sub.2O.sub.3, 8-12 weight percent MgO and 0.25-3 weight percent R.sub.2O, where R.sub.2O equals the sum of Li.sub.2O and Na.sub.2O, has a fiberizing temperature less than about 2650 F., and a T of at least 80 F. By using oxide-based refractory-lined furnaces the cost of production of glass fibers is substantially reduced in comparison with the cost of fibers produced using a platinum-lined melting furnace. High strength composite articles including the high strength glass fibers are also disclosed.

The present invention concerns a glass fibre manufacturing plant comprising a forehearth (31) comprising a longitudinal wall provided with at least one burner assembly comprising: (A) a burner block (20) made of a refractory material and comprising a through-passage and comprising a hot surface (20H) forming a portion of the longitudinal wall (31 L); and (B) a burner sub-assembly comprising: (a) an oxy-burner (1) comprising a downstream end ending at a free end of the downstream end, wherein a cross-sectional area of said downstream end of the oxy-burner body decreases towards the free end of the downstream end; characterized in that, the burner sub-assembly further comprises: (b) a cooling unit (3) comprising: a cooling plate (5) comprising an aperture which geometry matches the geometry of the downstream end of the oxy-burner which is inserted in said aperture to form a thermal contact therewith; a cooling channel (3C) defined by walls and comprising an inlet (3U) and an outlet (3D) for circulating a refrigerating fluid, wherein a cooling wall (5W) of said cooling channel is formed by a portion of the cooling plate, and in that, the cooling plate is encased in the through-passage.

A method of forming high strength glass fibers in a refractory-lined glass melter, products made there from and batch compositions suited for use in the method are disclosed. The glass composition for use in the method of the present invention is up to about 64-75 weight percent SiO.sub.2, 16-24 weight percent Al.sub.2O.sub.3, 8-12 weight percent MgO and 0.25-3 weight percent R.sub.2O, where R.sub.2O equals the sum of Li.sub.2O and Na.sub.2O, has a fiberizing temperature less than about 2650 F., and a T of at least 80 F. By using oxide-based refractory-lined furnaces the cost of production of glass fibers is substantially reduced in comparison with the cost of fibers produced using a platinum-lined melting furnace. High strength composite articles including the high strength glass fibers are also disclosed.