In illustrative implementations of this invention, a crucible kiln heats glass such that the glass becomes or remains molten. A nozzle extrudes the molten glass while one or more actuators actuate movements of the nozzle, a build platform or both. A computer controls these movements such that the extruded molten glass is selectively deposited to form a 3D glass object. The selective deposition of molten glass occurs inside an annealing kiln. The annealing kiln anneals the glass after it is extruded. In some cases, the actuators actuate the crucible kiln and nozzle to move in horizontal x, y directions and actuate the build platform to move in a z-direction. In some cases, fluid flows through a cavity or tubes adjacent to the nozzle tip, in order to cool the nozzle tip and thereby reduce the amount of glass that sticks to the nozzle tip.

One aspect is an oven including a melting crucible with a crucible wall, a solids feed with an outlet, a gas inlet and a gas outlet, wherein in the melting crucible the gas inlet is arranged below the solids feed outlet and the gas outlet is arranged at the same height as or above the solids feed outlet. One aspect further relates to a process for making a quartz glass body, including providing and introducing a bulk material selected from silicon dioxide granulate and quartz glass grain into the oven and providing a gas, making a glass melt from the bulk material, and making a quartz glass body from at least a part of the glass melt. One aspect relates to a quartz glass body obtainable by this process and a light guide, an illuminant and a formed body which are each obtainable by processing the quartz glass body further.

One aspect is an oven including a melting crucible with a crucible wall, a solids feed with an outlet, a gas inlet and a gas outlet, wherein in the melting crucible the gas inlet is arranged below the solids feed outlet and the gas outlet is arranged at the same height as or above the solids feed outlet. One aspect further relates to a process for making a quartz glass body, including providing and introducing a bulk material selected from silicon dioxide granulate and quartz glass grain into the oven and providing a gas, making a glass melt from the bulk material, and making a quartz glass body from at least a part of the glass melt. One aspect relates to a quartz glass body obtainable by this process and a light guide, an illuminant and a formed body which are each obtainable by processing the quartz glass body further.

The present invention relates to a submerged combustion furnace for melting ceramic frits by means of a submerged combustion process, said furnace comprising at least one control loop with feedback of the overall weight regulating at least one process variable of the furnace for producing ceramic frit. The invention also relates to a regulating method for a submerged combustion furnace having these features, whereby obtaining a batch production of a ceramic frit having certain characteristics. The regulating method is implemented in the system by means of regulating process variables relating to the production of molten material during production.

The present invention relates to a submerged combustion furnace for melting ceramic frits by means of a submerged combustion process, said furnace comprising at least one control loop with feedback of the overall weight regulating at least one process variable of the furnace for producing ceramic frit. The invention also relates to a regulating method for a submerged combustion furnace having these features, whereby obtaining a batch production of a ceramic frit having certain characteristics. The regulating method is implemented in the system by means of regulating process variables relating to the production of molten material during production.

A prefiner (28) is described and includes a chamber (34) for receiving molten glass exiting a submerged combustion melter. The prefiner (28) also includes a foam breaker (36) and an exit conduit (38). The molten glass holding chamber includes a top portion (42), a bottom portion (40), and an enclosing sidewall (44). The top portion (42) includes an opening to accommodate the foam breaker (36), which is positioned to break the glass bubbles within the chamber. The exit conduit (38) resides within the chamber (34) and is in fluid communication with an outlet (68) in the sidewall (44). The exit conduit (38) is positioned to permit molten glass to flow from the lower section of the chamber to the outlet (68) and to the next stage of processing, typically a finer.

A prefiner (28) is described and includes a chamber (34) for receiving molten glass exiting a submerged combustion melter. The prefiner (28) also includes a foam breaker (36) and an exit conduit (38). The molten glass holding chamber includes a top portion (42), a bottom portion (40), and an enclosing sidewall (44). The top portion (42) includes an opening to accommodate the foam breaker (36), which is positioned to break the glass bubbles within the chamber. The exit conduit (38) resides within the chamber (34) and is in fluid communication with an outlet (68) in the sidewall (44). The exit conduit (38) is positioned to permit molten glass to flow from the lower section of the chamber to the outlet (68) and to the next stage of processing, typically a finer.

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.

This invention relates to using a production glass furnace to melt waste glass and other glass constituents thereby providing a radiant heat source within the furnace to efficiently gasify organic waste materials recovered from a variety of waste streams to thereby produce a synthesis gas (Syngas) that is comprised mostly of carbon monoxide, hydrogen, and carbon dioxide that can be further refined and sold as a high value fuel. The gasification of the organic waste within the production glass furnace has minimal impact on the composition of the glass melt thus allowing for the production of the same range of glass products as if no organic waste was added to the furnace.

This invention relates to using a production glass furnace to melt waste glass and other glass constituents thereby providing a radiant heat source within the furnace to efficiently gasify organic waste materials recovered from a variety of waste streams to thereby produce a synthesis gas (Syngas) that is comprised mostly of carbon monoxide, hydrogen, and carbon dioxide that can be further refined and sold as a high value fuel. The gasification of the organic waste within the production glass furnace has minimal impact on the composition of the glass melt thus allowing for the production of the same range of glass products as if no organic waste was added to the furnace.