Abstract: A glass tube manufacturing apparatus for manufacturing glass tubing includes a glass delivery tank with molten glass. The glass delivery tank has a bottom opening. A bell has an upper portion with an outer diameter located at the bottom opening. A heating apparatus is at least partially disposed around the bell. The heating apparatus includes a heated portion and a muffle portion located below the heated portion. A lower extended muffle structure extends downwardly from the muffle portion. The lower extended muffle structure extending about the glass tubing on all sides to manage convective airflow therethrough.

Abstract: A muffle for a glass tube forming process includes an inlet end coupled to a bowl, an outlet end having an inner dimension larger than an inner dimension of the inlet end, and a sidewall extending from inlet end to the outlet end. A radial distance from a center axis of the muffle to an inner surface of the sidewall increases from the inlet end to the outlet end and the sidewall is substantially free of abrupt changes in the radial distance that produce instability regions within the muffle. The muffle includes a channel between an outer surface of a portion of the sidewall and an insulating layer disposed about the sidewall, the channel being operable to pass a heat transfer fluid into thermal communication with the sidewall to provide cooling to the muffle. Glass forming systems including the muffle and glass tube forming processes are also disclosed.

Abstract: A muffle for a glass tube forming process includes an inlet end coupled to a bowl, an outlet end having an inner dimension larger than an inner dimension of the inlet end, and a sidewall extending from inlet end to the outlet end. A radial distance from a center axis of the muffle to an inner surface of the sidewall increases from the inlet end to the outlet end and the sidewall is substantially free of abrupt changes in the radial distance that produce instability regions within the muffle. The muffle includes a channel between an outer surface of a portion of the sidewall and an insulating layer disposed about the sidewall, the channel being operable to pass a heat transfer fluid into thermal communication with the sidewall to provide cooling to the muffle. Glass forming systems including the muffle and glass tube forming processes are also disclosed.

Abstract: A glass tube manufacturing apparatus for manufacturing glass tubing includes a glass delivery tank with molten glass. The glass delivery tank has a bottom opening. A bell has an upper portion with an outer diameter located at the bottom opening. A heating apparatus is at least partially disposed around the bell. The heating apparatus includes a heating portion and a muffle portion located below the heating portion. A lower extended muffle structure extends downwardly from the muffle portion. The lower extended muffle structure extending about a periphery of the glass tubing to manage convective airflow therethrough.

Abstract: A bell positioning apparatus for glass tubing manufacturing includes a bell and a support connected to the bell. A bell positioning apparatus is attached to the support and configured to move the support and the bell with at least three degrees of freedom. The bell positioning apparatus includes a platform, a platform frame, and one or more frame legs. A frame leg dimensional stability apparatus maintains a temperature variation within 6.5° C. per meter of distance between each frame leg for an extended period of time, e.g. 4 hours.

Abstract: A bell positioning apparatus for glass tubing manufacturing includes a bell and a support connected to the bell. A bell positioning apparatus is attached to the support and configured to move the support and the bell with at least three degrees of freedom. The bell positioning apparatus includes a platform, a platform frame, and one or more frame legs. A frame leg dimensional stability apparatus maintains a temperature variation within 6.5° C. per meter of distance between each frame leg for an extended period of time, e.g. 4 hours.

Abstract: Methods for producing a glass ribbon include the step of drawing a glass ribbon from a quantity of molten glass and detecting an instability in the glass ribbon. In response to the detected instability, the method can further include the step of automatically adjusting an operating variable for each of a plurality of stabilizing elements simultaneously with a controller to at least partially counter the detected instability.

Abstract: Methods for producing a glass ribbon include the step of drawing a glass ribbon from a quantity of molten glass and detecting an instability in the glass ribbon. In response to the detected instability, the method can further include the step of automatically adjusting an operating variable for each of a plurality of stabilizing elements simultaneously with a controller to at least partially counter the detected instability.

Abstract: A method and apparatus for forming a glass sheet using a fusion down-draw process, wherein the heating powers of the heating elements are managed such that in case of a failure of one heating element, the heating power of the adjacent heating element is immediately increased. The method decreases the thermal stress the forming body is exposed to due to the failure of the heating element.