The invention provides methods of making man-made vitreous fibres (MMVF), comprising incorporating metallic aluminium into the mineral charge, with the benefit of reduced shrinkage of consolidated MMVF products.

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.

The present invention refers to a method for producing a glass body with high silicic-acid content by drawing a softened glass mass from an elongated, substantially cylindrical crucible in that SiO.sub.2 granules are supplied from above into the crucible, the SiO.sub.2 granules are heated to a softening temperature, so that the softened glass mass which comprises a melt surface is formed, the softened glass mass is drawn off via a bottom opening of the crucible so as to form a glass strand, and the glass strand is cut to length to obtain the glass body, wherein due to the supply of the SiO.sub.2 granules a bulk heap is formed that covers the melt surface in part while leaving a melt edge, and wherein the melt surface is optically detected. To improve the fusion behavior of the granules and to suppress or altogether prevent the formation of a sinter crust, it is suggested according to the invention that during the optical detection of the melt surface the width of at least a sub-section of the melt edge is determined consecutively and is set to a value within a target width range through the supply rate of the SiO.sub.2 granules.

The present invention refers to a method for producing a glass body with high silicic-acid content by drawing a softened glass mass from an elongated, substantially cylindrical crucible in that SiO.sub.2 granules are supplied from above into the crucible, the SiO.sub.2 granules are heated to a softening temperature, so that the softened glass mass which comprises a melt surface is formed, the softened glass mass is drawn off via a bottom opening of the crucible so as to form a glass strand, and the glass strand is cut to length to obtain the glass body, wherein due to the supply of the SiO.sub.2 granules a bulk heap is formed that covers the melt surface in part while leaving a melt edge, and wherein the melt surface is optically detected. To improve the fusion behavior of the granules and to suppress or altogether prevent the formation of a sinter crust, it is suggested according to the invention that during the optical detection of the melt surface the width of at least a sub-section of the melt edge is determined consecutively and is set to a value within a target width range through the supply rate of the SiO.sub.2 granules.

A glass furnace includes a furnace chamber for containing glass melt and a screw conveyor for receiving glass batch material and feeding the glass batch material to the furnace chamber. A dam wall is disposed with respect to the screw conveyor such that batch material from the screw conveyor must flow upward over the dam wall before entering the furnace chamber. The top of the dam wall may be below the level of the melt pool in the furnace chamber.

A melter apparatus includes a floor, a ceiling, and a wall connecting the floor and ceiling at a perimeter of the floor and ceiling, a melting zone being defined by the floor, ceiling and wall, the melting zone having a feed inlet and a molten glass outlet positioned at opposing ends of the melting zone. Melter apparatus include an exit end having a melter exit structure for discharging turbulent molten glass formed by one or more submerged combustion burners, the melter exit structure fluidly and mechanically connecting the melter vessel to a molten glass conditioning channel. The melter exit structure includes a fluid-cooled transition channel configured to form a frozen glass layer or highly viscous glass layer, or combination thereof, on inner surfaces of the fluid-cooled transition channel and thus protect the melter exit structure from mechanical energy imparted from the melter vessel to the melter exit structure.

A method for supplying pre-heated particulate mineral material from a separating cyclone to a cyclone furnace inlet includes receiving the mineral material in a material receiving conduit from a bottom outlet of the separating cyclone. There is a first pressure in the receiving conduit. The mineral material is fluidised in the receiving conduit and flows upwards in an inclined elongated gas-lock valve from a lowermost section of the receiving conduit to an uppermost section of an outlet conduit. The mineral material is supplied from the outlet conduit to the inlet of the cyclone furnace, wherein there is a second pressure that is higher than the first pressure. A fluidisation unit in the gas-lock valve maintains the particulate mineral material in a fluidised state, such that the fluidised particulate mineral material flows due to gravity from the material receiving conduit, upwards through the gas-lock valve and to the outlet conduit.

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 glass melting furnace including a melt chamber configured to receive a glass melt which forms a glass melt top surface; at least one batch feeder configured to feed batch material into the melt chamber below a level of the glass melt top surface, the batch feeder arranged at a side wall, a back wall, or a bottom of the melt chamber, plural electrodes arranged in the melt chamber below the level of the glass melt top surface and configured to heat the glass melt, the electrodes spaced apart from each other, wherein the electrodes are arranged so that a flow with a horizontal and a vertical component of movement is created in the glass melt, wherein the electrodes are arranged so that a helical flow in the glass melt is created with an axis of rotation substantially perpendicular to the glass melt top surface.