Abstract: Heating apparatuses and methods for glass tubing manufacturing are disclosed. A heating apparatus for glass tubing manufacturing includes a bowl configured to receive molten glass and a plurality of heating elements thermally coupled to the bowl. The bowl has a bowl height and includes a tub portion configured to hold the molten glass, a bowl well extending beneath the tub portion, and an orifice at a distal end of the bowl well. The plurality of heating elements include a first heating element disposed at a first vertical location along the bowl height, a second heating element disposed at a second vertical location along the bowl height, wherein the first vertical location is vertically spaced apart from the second vertical location.

Abstract: A glass manufacturing apparatus includes a delivery tube terminating at a lower end in a delivery slot. A stream of molten material is delivered along a travel plane in a travel direction. A first plate is positioned adjacent the lower end of the delivery tube on a first side of the travel plane. The first plate includes a first edge extending adjacent the travel plane and a first thermal expansion slot extending from the first edge to a first interior. A second plate is positioned adjacent the lower end of the delivery tube on a second side of the travel plane. The second plate includes a second edge extending adjacent the travel plane and a second thermal expansion slot extending from the second edge to a second interior. The second edge is spaced apart from the first edge to define a delivery opening through which the delivery tube extends.

Abstract: An apparatus for producing composite glass tube with a plurality of glass layers includes a plurality of cylindrical containers of increasing inner dimensions concentrically arranged and stationary. Each cylindrical container includes a side wall, bottom wall, and a delivery ring. Adjacent cylindrical containers define an annular chamber, a flow control region, and an annular flow channel therebetween. The apparatus includes at least one flow control valve positioned in the flow control region and translatable relative to the adjacent cylindrical containers. Translation of the flow control valves relative to the cylindrical containers is operable to change an impedance to flow of molten glass through the flow control region, thereby modifying an overall flow rate or circumferential distribution of molten glass from the cylindrical containers. Systems and methods for producing composite glass tube using the apparatus are also disclosed.

Abstract: An apparatus for producing composite glass tube with a plurality of glass layers includes a plurality of cylindrical containers of increasing inner dimensions concentrically arranged and stationary. Each cylindrical container includes a side wall, bottom wall, and a delivery ring. Adjacent cylindrical containers define an annular chamber, a flow control region, and an annular flow channel therebetween. The apparatus includes at least one flow control valve positioned in the flow control region and translatable relative to the adjacent cylindrical containers. Translation of the flow control valves relative to the cylindrical containers is operable to change an impedance to flow of molten glass through the flow control region, thereby modifying an overall flow rate or circumferential distribution of molten glass from the cylindrical containers. Systems and methods for producing composite glass tube using the apparatus are also disclosed.

Abstract: An apparatus for producing composite glass tube with a plurality of glass layers includes a plurality of cylindrical containers of increasing inner dimensions concentrically arranged and stationary. Each cylindrical container includes a side wall, bottom wall, and a delivery ring. Adjacent cylindrical containers define an annular chamber, a flow control region, and an annular flow channel therebetween. The apparatus includes at least one flow control valve positioned in the flow control region and translatable relative to the adjacent cylindrical containers. Translation of the flow control valves relative to the cylindrical containers is operable to change an impedance to flow of molten glass through the flow control region, thereby modifying an overall flow rate or circumferential distribution of molten glass from the cylindrical containers. Systems and methods for producing composite glass tube using the apparatus are also disclosed.

Abstract: An apparatus for producing composite glass tube with a plurality of glass layers includes a plurality of cylindrical containers of increasing inner dimensions concentrically arranged and stationary. Each cylindrical container includes a side wall, bottom wall, and a delivery ring. Adjacent cylindrical containers define an annular chamber, a flow control region, and an annular flow channel therebetween. The apparatus includes at least one flow control valve positioned in the flow control region and translatable relative to the adjacent cylindrical containers. Translation of the flow control valves relative to the cylindrical containers is operable to change an impedance to flow of molten glass through the flow control region, thereby modifying an overall flow rate or circumferential distribution of molten glass from the cylindrical containers. Systems and methods for producing composite glass tube using the apparatus are also disclosed.

Abstract: Heating apparatuses and methods for glass tubing manufacturing are disclosed. A heating apparatus for glass tubing manufacturing includes a bowl configured to receive molten glass and a plurality of heating elements thermally coupled to the bowl. The bowl has a bowl height and includes a tub portion configured to hold the molten glass, a bowl well extending beneath the tub portion, and an orifice at a distal end of the bowl well. The plurality of heating elements include a first heating element disposed at a first vertical location along the bowl height, a second heating element disposed at a second vertical location along the bowl height, wherein the first vertical location is vertically spaced apart from the second vertical location.

Abstract: A glass melting furnace is operated under a set of control parameters. A glass batch is fed into the glass melting furnace and melted into molten glass. During the melting, a surface layer comprising a portion of the glass batch and foam forms over the molten glass. A plurality of thermograms of the interior of the glass melting furnace is obtained. The thermograms are analyzed to determine whether there is instability in the thermodynamics of the surface layer. The set of control parameters are then adjusted to reduce a determined instability in the thermodynamics of the surface layer.

Abstract: A glass melting furnace is operated under a set of control parameters. A glass batch is fed into the glass melting furnace and melted into molten glass. During the melting, a surface layer comprising a portion of the glass batch and foam forms over the molten glass. A plurality of thermograms of the interior of the glass melting furnace is obtained. The thermograms are analyzed to determine whether there is instability in the thermodynamics of the surface layer. The set of control parameters are then adjusted to reduce a determined instability in the thermodynamics of the surface layer.

Abstract: A mandrel 1 includes a top support 10, a first edge support 20, a bottom support 30, and a second edge support 40. The top support and first edge support make-up a first support section. The bottom support and second edge support make-up a second support section. The first support section and the second support section are disposed relative to one another so as to form an outer circumference. A jack 50 is coupled to the first and second support sections and is configured to move the first and second support sections relative to one another so as to adjust the outer circumference of the mandrel. A locking element 60 removably is coupled to the first and second support sections to selectively prevent relative movement between the first and second support sections.

Abstract: A mandrel 1 includes a top support 10, a first edge support 20, a bottom support 30, and a second edge support 40. The top support and first edge support make-up a first support section. The bottom support and second edge support make-up a second support section. The first support section and the second support section are disposed relative to one another so as to form an outer circumference. A jack 50 is coupled to the first and second support sections and is configured to move the first and second support sections relative to one another so as to adjust the outer circumference of the mandrel. A locking element 60 removably is coupled to the first and second support sections to selectively prevent relative movement between the first and second support sections.