Stirrers for minimizing erosion of refractory metal vessels in a glass making system

• US 8,256,951 B2
• Filed: 12/21/2006
• Issued: 09/04/2012
• Est. Priority Date: 12/21/2006
• Status: Expired due to Fees

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Adelsberg, Lee Martin, Goller, Martin Herbert, Lineman, David Myron, Murphy, James Patrick
• Primary Examiner(s): Cooley, Charles E
• Application Number:
  US11/643,059
• Publication Number:
  US 20080151687A1
• Time in Patent Office: 2,084 Days
• Field of Search: 65178-180, 366/325.1, 366/328.1, 366/328.2, 366/279, 366342-343, 366262-265, 366/270
• US Class Current: 366/328.1
• CPC Class Codes: B01F 27/0531 with particular surface characteristics, e.g. coated or rough
• CPC Class Codes: B01F 27/1123 sickle-shaped, i.e. curved in at least one direction
• CPC Class Codes: B01F 27/1152 with separate elements other than discs fixed on the discs, e.g. vanes fixed on the discs
• CPC Class Codes: B01F 27/50 Pipe mixers, i.e. mixers wherein the materials to be mixed flow continuously through pipes, e.g. column mixers
• CPC Class Codes: B01F 27/80 with stirrers rotating about a substantially vertical axis
• CPC Class Codes: C03B 5/1675 Platinum group metals
• CPC Class Codes: C03B 5/187 with moving elements

Abstract

Stirring apparatuses for stirring molten glass are disclosed. The method includes stirring a molten glass with a stirrer comprising a layer containing at least about 50% iridium. An apparatus comprising an iridium-containing layer is also presented. In one embodiment, an apparatus for stirring molten glass includes a cylinder comprising a bore. A stirrer may be disposed in the bore. The stirrer may include a platinum or platinum alloy shaft coaxial with the cylinder. A plurality of impellers may project radially from the shaft into close proximity of a wall of the cylinder. Each impeller may include an arcuate distal end portion farthest from the shaft. The distal end portion of each impeller consists of iridium or an iridium alloy and the remainder of the impeller consists of platinum or a platinum alloy. The stirring apparatuses reduce metal loss from the refractory metal of the stirring apparatus.

Claims

1. An apparatus for stirring molten glass comprising:

a cylinder comprising a bore;

a stirrer disposed in the bore, the stirrer comprising;

a platinum or platinum alloy shaft coaxial with the cylinder;

a plurality of impellers projecting radially from the shaft into close proximity of a wall of the cylinder, each impeller including an arcuate distal end portion farthest from the shaft; and

wherein the distal end portion of each impeller consists of iridium or an iridium alloy and the remainder of the impeller consists of platinum or a platinum alloy.

2. The apparatus according to claim 1 wherein the distal end portion of each impeller defines a plurality of holes extending through a thickness thereof.

3. The apparatus according to claim 1 wherein the distal end portion of each impeller comprises a plurality of grooves in a surface thereof, the plurality of grooves aligned parallel to the long axis of the platinum or platinum alloy shaft and perpendicular to a flow direction of the molten glass over the surface of the distal end portion.

4. The apparatus according to claim 1 further comprising a plurality of impeller sets, each impeller set comprising three impellers, and each impeller comprising two impeller blades anchored to each other to form a substantially circular impeller.

5. The apparatus according to claim 1 wherein an inside surface of the cylinder wall comprises a plurality of grooves aligned parallel to the shaft.

6. The apparatus according to claim 5 wherein the cylinder wall comprises iridium.

7. A stirrer for stirring molten glass comprising:

a platinum alloy shaft;

a plurality of impellers extending radially from the shaft, each impeller comprising an arcuate distal end portion farthest from the shaft; and

wherein the distal end portion of each impeller consists of iridium or an iridium alloy and the remainder of each impeller consists of platinum or a platinum alloy.