Submerged combustion burners having a burner body, a burner tip connected thereto. Submerged combustion melters including the burners and methods of using them to produce molten glass. The burner body has an external conduit and first and second internal conduits substantially concentric therewith, forming first and second annuli for passing a cooling fluid therethrough. The burner tip body is connected to the burner body at ends of the external and second internal conduits. The burner tip includes a generally central flow passage for a combustible mixture, the flow passage defined by an inner wall of the burner tip. The burner tip includes a crown portion defining a circumferential concavity.

Submerged combustion glass manufacturing systems and methods include a melter having a floor, a roof, a wall structure connecting the floor and roof, and one or more submerged combustion burners mounted in the floor, roof, and/or wall structure discharging combustion products including water vapor under a level of material being melted in the melter and create turbulent conditions in the material. The floor, roof, or wall structure may include fluid-cooled refractory material and an optional metallic external shell, or the metallic shell may include coolant passages. One or more conduits drain water condensed from the water vapor from regions of refractory material substantially saturated with the water, and/or from burner supports.

A submerged combustion melter and system are disclosed. The submerged combustion melter includes a bottom wall, at least one side wall extending upwardly from the bottom wall, a crown extending inwardly with respect to the at least one side wall and over the bottom wall to establish a melting chamber, an exhaust port configured to exhaust gas from the melting chamber, at least one baffle extending from the at least one side wall to divide the melting chamber into melting sub-chambers that share the exhaust port, at least one inlet configured for introducing a glass batch into the submerged combustion melter, and at least one outlet configured to remove molten glass from the at least one melting chamber.

A method of of fining low-density submerged combustion glass includes introducing unfined molten glass produced in a submerged combustion melter into a fining chamber of a fining tank and, further, introducing additive particles into the fining chamber that comprise a glass reactant material and one or more fining agents. The one or more fining agents are released into the molten glass bath upon consumption of the additive particles in the molten glass bath to chemically fine the molten glass bath and the glass reactant material includes one or more materials that integrate into the molten glass bath upon melting. Additionally, the method includes discharging fined molten glass out of the fining chamber of the fining tank. The discharged fined molten glass has a volume percentage of gas bubbles that is less than the volume percentage of gas bubbles in the unfined molten glass introduced into the fining chamber.

The present invention relates to a process and a facility for the continuous vitrification treatment of fibrous materials, and in particular of asbestos and/or of asbestos-containing materials.

According to the invention, this process comprises the following steps: a bath of molten glass at a temperature of 1300° C. to 1600° C. is prepared; introduced into said bath of molten glass are said fibrous materials and optionally melting additives chosen so that said bath has, after addition of these fibrous materials and melting additives, the following composition: SiO.sub.2: between 30% and 55% by weight; FeO: between 25% and 45% by weight; alkali and alkaline-earth metal oxides: between 15% and 25% by weight; an oxidizer and a fuel are injected under pressure into said molten bath by means of at least one lance, one end of which is immersed in said bath; said oxidizer being introduced in a molar amount greater than or equal to the molar amount of fuel needed to maintain the temperature of the bath between 1300° C. and 1600° C.; and the temperature of at least one portion of the molten glass is lowered so as to render it solid.

A for melting batch material includes a furnace equipped with a submerged burner, a system for supplying the submerged burner with fuel gas and with oxidizer, a system for supplying the furnace with raw material including fragments of mineral wool below the surface of the molten batch materials, a system for supplying the furnace with raw material including a vertical duct for receiving raw material through its upper side and for conveying this raw material downward toward the molten batch materials. The duct receives the combustion flue gases originating from the furnace and conveys them upward through the raw material in the duct. A system supports the solid raw material in the duct and is positioned above the surface of the molten batch material and retains the solid raw material in the duct and lets descending molten raw material pass through to fall into the molten batch material.

A method of melting glass and glass-ceramics that includes the steps: conveying a batch of raw materials into a submerged combustion melting apparatus, the melting apparatus having liquid-cooled walls and a floor; directing a flame into the batch of raw materials and the melted batch with sufficient energy to form the raw materials into the melted batch; and heating a delivery orifice assembly in the floor of the submerged melting apparatus to convey the melted batch through the orifice assembly into a containment vessel. The melted batch has a glass or glass-ceramic composition that is substantially reactive to a refractory material comprising one or more of silica, zirconia, alumina, platinum and platinum alloys.

A method of fining low-density submerged combustion glass is disclosed. The method involves introducing unfined molten glass produced in a submerged combustion melter into a fining chamber of a downstream fining tank. Additionally, additive particles are also introduced into the fining chamber to release one or more fining agents into the molten glass bath contained in the fining chamber to accelerate the removal of bubbles from the molten glass bath. The fining of the molten glass bath as assisted by the one or more fining agents allows for fined glass to be discharged from the fining tank that has fewer bubbles and a greater density than that of the unfined molten glass introduced into the fining tank. Additive particles that include a physical mixture of a glass reactant material and the fining agent(s) are also disclosed.

A forehearth system includes a superstructure including refractory bricks that frame a molten glass tank, with a burner block including a discharge throat that extends its distal end formed from a refractory material that is within the superstructure above the molten glass tank. At least one oxygen fuel forehearth burner is within the burner block including a burner body, a fuel pipe within the burner body having a fuel inlet for receiving fuel and a fuel outlet, and an oxygen pipe within the burner body having an oxygen inlet for receiving oxygen and an oxygen outlet. The oxygen pipe is positioned coaxially outside the fuel pipe. The fuel outlet extends beyond the oxygen pipe and beyond the burner body so that the oxygen first reaching the fuel and thus a flame when operating is delayed until the discharge throat.

In a process for manufacturing glass, a mixture of solid glass-forming materials may be melted by application of heat from one or more submerged combustion burners to produce a volume of unrefined molten glass comprising, by volume, 20% to 40% gas bubbles. A refining agent may be introduced into the unrefined molten glass to promote gas bubble removal from the molten glass. The unrefined molten glass including the refining agent may be heated at a temperature in the range of 1200° C. to 1500° C. to produce a volume of refined molten glass. The refined molten glass may comprise, by volume, fewer gas bubbles than the unrefined molten glass. A colorant material may be introduced into the refined molten glass to produce a volume of molten glass having a final desired color.