A process and apparatus for manufacturing glass. A mixture of solid glass-forming materials comprising at least one fining agent are introduced into a doghouse located upstream of an elongated tank. The glass-forming materials are melted in the doghouse at a temperature at or above a fining-onset temperature of the at least one fining agent by application of heat from one or more submerged combustion burners. The resulting molten glass is relatively foamy and may comprise greater than 25 vol. % gas bubbles. The molten glass is directed from the doghouse into an upstream end of the tank where it is refined to produce molten glass having on average less than 20 seeds per ounce.

A method for producing a glass product is provided. The method includes providing a glass melt; hot forming the glass melt to obtain a glass product; and transferring the glass melt from a first region to a second region through a tube. The tube has a part that protrudes with a length into the glass melt in the first region. The part being at a distance from an inner base lying directly thereunder. The length and the distance are configured so that little defective glass gets into the tube and is transferred to the second region.

A method for reconditioning a glass manufacturing system includes establishing a reducing atmosphere in a glass melting vessel and draining a glass melt composition from the melting vessel while the reducing atmosphere is in the vessel. The pressure of the reducing atmosphere is greater than the pressure of the atmosphere surrounding the melting vessel and the reducing atmosphere is established by operating at least one combustion burner in the melting vessel in a fuel-rich condition.

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.

An apparatus and methods of refining glass, in a multi-stage, downwardly cascading manner, include a melting chamber housing molten glass and having an outlet, a first refining chamber downstream from the melting chamber and having a first outlet and a first inlet below the outlet of the melting chamber, and a second refining chamber downstream from the first refining chamber and having a second outlet and a second inlet below the first outlet of the first refining chamber. The first refining chamber has a first negative pressure and the second refining chamber has a second negative pressure.

A process and apparatus for manufacturing glass. A mixture of solid glass-forming materials comprising at least one fining agent are introduced into a doghouse located upstream of an elongated tank. The glass-forming materials are melted in the doghouse at a temperature at or above a fining-onset temperature of the at least one fining agent by application of heat from one or more submerged combustion burners. The resulting molten glass is relatively foamy and may comprise greater than 25 vol. % gas bubbles. The molten glass is directed from the doghouse into an upstream end of the tank where it is refined to produce molten glass having on average less than 20 seeds per ounce.

An apparatus and method of refining molten glass are disclosed. An upstream vessel contains molten glass, a downstream vessel is arranged downstream of the upstream vessel, and vacuum refining vessels are located between the upstream vessel and the downstream vessel and are in separate, alternating fluid communication with the upstream vessel and in separate, alternating fluid communication with the downstream vessel.

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.

A glass manufacturing apparatus includes a dissolving vessel configured to dissolve a glass raw material to produce a molten glass, a forming vessel configured to form the molten glass into a predetermined shape, and glass supply tubes configured to convey the molten glass from the dissolving vessel to the forming vessel. The glass supply tubes each include a tube body, a flange portion, which is arranged in an outer circumferential portion of the tube body and has first and second parts, an electrode portion arranged in the first part, and a temperature difference setting portion configured to cause a temperature difference between the first and second parts. The temperature difference setting portion sets a temperature of the first part to be higher than that of the second part.

Method and apparatus for removing bubbles from a molten substrate. The molten substrate from a furnace passes through a downtube to reach additional manufacturing tools, such as an extrusion bushing. One or more ultrasonic sensors are arranged along the downtube. The ultrasonic sensor(s) transmit ultrasonic energy into the molten substrate and measure a characteristic of the ultrasonic energy, such as a propagation time for the ultrasonic energy to be reflected back to the ultrasonic sensor(s). A bubble is detected when a change in the characteristic of the ultrasonic energy is detected. When a bubble is detected, flow through the downtube is diverted to a duct to remove a slug of molten substrate that includes the bubble.