# US 2021/0276910 A1 · Glass manufacturing apparatus and methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0276910 A1 - Document ID: US20210276910A1 - Status: Published application - Kind: A1 - Application number: 16/327,092 - Filed: 2017-08-16 - Published: 2021-09-09 - Earliest claimed: 2016-08-24 - Assignees: Corning Incorporated - Applicants: Corning Incorporated - Inventors: Mark Alan Cook; Franck Olivier Hounkpevi; Pierre Laronze - Web page: https://patentgrep.com/patent/US20210276910A1 ## CPC - C03B 5/24: Automatically regulating the melting process - C03B 7/005: {Controlling, regulating or measuring} - C03B 5/187: with moving elements - C03B 17/064: {by the overflow downdraw fusion process; Isopipes therefor} - C03B: MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES ## Abstract A method of controlling a flowrate of molten material at a downstream location in a glass manufacturing process can include mixing the molten material at an upstream location positioned upstream from the downstream location relative to a flow direction of the molten material with a shaft including a plurality of protrusions. The method can also include measuring a torque of the shaft, measuring a level of the molten material at the upstream location, and calculating a viscosity of the molten material at the upstream location based on the measured torque and the measured level. In addition, the method can include estimating the flowrate based on the calculated viscosity, and controlling the flowrate at the downstream location based on the estimated flowrate. ## Claims ### Claim 1 A method of controlling a flowrate of molten material at a downstream location in a glass manufacturing process comprising: mixing the molten material at an upstream location positioned upstream from the downstream location relative to a flow direction of the molten material with a shaft comprising a plurality of protrusions; measuring a torque of the shaft; measuring a level of the molten material at the upstream location; calculating a viscosity of the molten material at the upstream location based on the measured torque and the measured level; estimating the flowrate based on the calculated viscosity; and controlling the flowrate of molten material at the downstream location based on the estimated flowrate. ### Claim 2 (depends on 1) The method of claim 1, wherein controlling the flowrate of molten material comprises comparing the estimated flowrate to a predetermined flowrate. ### Claim 3 (depends on 1) The method of claim 1, wherein controlling the flowrate of molten material comprises adjusting a temperature of the molten material at a midstream location positioned between the upstream location and the downstream location based on the estimated flowrate. ### Claim 4 (depends on 3) The method of claim 3, wherein adjusting the temperature of the molten material at the midstream location adjusts the flowrate of the molten material at the downstream location. ### Claim 5 (depends on 3) The method of claim 3, wherein adjusting the temperature of the molten material at the midstream location provides an adjusted flowrate of the molten material at the downstream location, the method further comprising forming a glass ribbon from the molten material at the adjusted flowrate. ### Claim 6 (depends on 1) The method of claim 1, wherein measuring the level of the molten material comprises measuring a height of the molten material relative to a length of the shaft. ### Claim 7 (depends on 1) The method of claim 1, wherein measuring the torque of the shaft comprises rotating a rotor mounted to the shaft relative to a stator, and wherein the stator is positioned to receive a signal from the rotor without physically contacting the rotor. ### Claim 8 (depends on 7) The method of claim 7, wherein the rotor is mounted to the shaft between two electrically nonconductive connectors. ### Claim 9 (depends on 7) The method of claim 7, wherein the rotor is mounted to the shaft with a double-flex coupler positioned between the rotor and the plurality of protrusions. ### Claim 10 A method of controlling a flowrate of molten material at a downstream location in a glass manufacturing process comprising: forming a glass ribbon from the molten material at the flowrate; calculating the flowrate of the molten material from which the glass ribbon was formed; calculating a viscosity of the molten material at an upstream location positioned upstream from the downstream location relative to a flow direction of the molten material; estimating the flowrate based on the calculated viscosity and the calculated flowrate; and controlling the flowrate of the molten material at the downstream location based on the estimated flowrate. ### Claim 11 (depends on 10) The method of claim 10, wherein calculating the flowrate of the molten material from which the glass ribbon was formed comprises separating a glass sheet from the glass ribbon and measuring a weight of the glass sheet. ### Claim 12 (depends on 10) The method of claim 10, wherein estimating the flowrate comprises estimating a first flowrate based on the calculated viscosity and estimating a second flowrate based on the calculated flowrate, and wherein controlling the flowrate comprises comparing the first estimated flowrate and the second estimated flowrate to a predetermined flowrate. ### Claim 13 (depends on 12) The method of claim 12, wherein controlling the flowrate of molten material comprises adjusting a temperature of the molten material at a midstream location positioned between the upstream location and the downstream location based on the first estimated flowrate and the second estimated flowrate. ### Claim 14 (depends on 13) The method of claim 13, wherein adjusting the temperature of the molten material at the midstream location comprises a first temperature adjustment based on the first estimated flowrate and a second temperature adjustment based on the second estimated flowrate ### Claim 15 (depends on 14) The method of claim 14, wherein the first temperature adjustment and the second temperature adjustment are performed at different times during the glass manufacturing process. ### Claim 16 (depends on 14) The method of claim 14, wherein the first temperature adjustment and the second temperature adjustment adjust the flowrate of the molten material at the downstream location. ### Claim 17 (depends on 14) The method of claim 14, wherein the first temperature adjustment and the second temperature adjustment provide an adjusted flowrate of the molten material at the downstream location, the method further comprising forming a glass ribbon from the molten material at the adjusted flowrate. ### Claim 18 (depends on 10) The method of claim 10, further comprising: mixing the molten material at the upstream location with a shaft comprising a plurality of protrusions; measuring a torque of the shaft; measuring a level of the molten material at the upstream location; and calculating the viscosity of the molten material at the upstream location based on the measured torque and the measured level. ### Claim 19 (depends on 18) The method of claim 18, wherein measuring the level of the molten material comprises measuring a height of the molten material relative to a length of the shaft. ### Claim 20 (depends on 18) The method of claim 18, wherein measuring the torque of the shaft comprises rotating a rotor mounted to the shaft relative to a stator, and wherein the stator is positioned to receive a signal from the rotor without physically contacting the rotor.