Method for tin bath monitoring and control
AssigneeAir Products and Chemicals, Inc.
InventorsReed Jacob Hendershot, Liang He, Michael J. Gallagher, Ranajit Ghosh
Life of this patent
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Abstract
A method of controlling defects in a glass product produced in a tin bath furnace includes measuring at least one parameter of an atmosphere associated with the tin bath furnace, wherein the parameter is selected from the group consisting of dew point and density, correlating the measured parameter with defects in the glass product, and controlling the measured parameter in a direction corresponding to decreased defects in the glass product by controlling a flow rate of a process gas relative to the furnace wherein the process gas includes one or more of hydrogen and nitrogen.
Claims22
A method of controlling defects in a glass product produced in a tin bath furnace, comprising:
- measuring at least one parameter of an atmosphere associated with the tin bath furnace, wherein the parameter includes a dew point of the atmosphere and/or a density of the atmosphere;
- correlating the measured parameter with defects in the glass product;
- controlling the measured parameter in a direction corresponding to decreased defects in the glass product by controlling a flow rate of a process gas relative to the tin bath furnace such that a flow rate of a purge gas exiting the tin bath furnace is increased to lower the dew point of the atmosphere to control the dew point of the atmosphere and the flow rate of the purge gas is decreased to increase the dew point of the atmosphere to control the dew point of the atmosphere;
- wherein the process gas includes one or more of hydrogen and nitrogen;
- and
- controlling a line speed of glass production to adjust a width of a ribbon of the glass product positioned on a tin bath of the tin bath furnace to decrease defects in the glass product.
A method of controlling defects in a glass product produced in a tin bath furnace, comprising:
- measuring at least one parameter of an atmosphere associated with the tin bath furnace, wherein the parameter is selected from the group consisting of a dew point of the atmosphere and a density of the atmosphere and wherein the atmosphere is of a vent flow from the tin bath furnace;
- correlating the measured parameter with defects in the glass product;
- controlling the measured parameter in a direction corresponding to decreased defects in the glass product by controlling a flow rate of a process gas relative to the furnace wherein the process gas includes one or more of hydrogen and nitrogen;
- correlating a line speed of glass production with defects in the glass product and controlling the flow rate of the process gas in a direction corresponding to decreased defects in the glass product;
- measuring a pressure differential and a temperature differential in the vent flow;
- and
- based on the measured pressure differential and the measured temperature differential, determining vent flow direction and vent flow rate.
A method of controlling defects in a glass product produced in a tin bath furnace, comprising:
- measuring a dew point of an atmosphere associated with the tin bath furnace;
- correlating the measured dew point with defects in the glass product;
- controlling the dew point in a direction corresponding to decreased defects in the glass product by controlling a flow rate of a process gas relative to the furnace such that the flow rate of a purge gas exiting the tin bath furnace is increased to lower the dew point of the atmosphere to control the dew point of the atmosphere and the flow rate of the purge gas is decreased to increase the dew point of the atmosphere to control the dew point of the atmosphere, wherein the dew point corresponds to a water vapor concentration in the atmosphere, and wherein the process gas includes one or more of hydrogen and nitrogen;
- measuring a density of the atmosphere associated with the tin bath furnace, wherein the measured density corresponds to a hydrogen concentration in the atmosphere;
- and
- controlling a ratio of hydrogen to water vapor concentrations in the atmosphere in a direction corresponding to decreased defects in the glass product by controlling the flow rate of the process gas relative to the furnace to increase the ratio of the hydrogen to the water vapor concentrations in response to the measured dew point being above a pre-selected threshold.
Dependencies are inferred from the claim text.