Chapter 7. Induction-Heated Molybdenum Delivery Systems (MODES)

  1. John B. Wachtman Jr.
  1. M. A. Smith and
  2. R. R. Thomas

Published Online: 26 MAR 2008

DOI: 10.1002/9780470313237.ch7

Proceedings of the 51st Conference on Glass Problems: Ceramic Engineering and Science Proceedings, Volume 12, Issue 3/4

Proceedings of the 51st Conference on Glass Problems: Ceramic Engineering and Science Proceedings, Volume 12, Issue 3/4

How to Cite

Smith, M. A. and Thomas, R. R. (2008) Induction-Heated Molybdenum Delivery Systems (MODES), in Proceedings of the 51st Conference on Glass Problems: Ceramic Engineering and Science Proceedings, Volume 12, Issue 3/4 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470313237.ch7

Author Information

  1. Corning Incorporated Corning, NY 14831

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1991

ISBN Information

Print ISBN: 9780470374986

Online ISBN: 9780470313237

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Keywords:

  • molybdenum;
  • thermal conditioning;
  • coupling;
  • contamination;
  • mechanism

Summary

Molybdenum glass delivery systems (MODES) replace conventional electric or gas-fired refractory delivery systems (channel, connector, forehearth, etc.) with a heated molybdenum pipe. MODES was developed at Corning in the late 70s, offering improved life, inclusion levels, and temperature control over conventional applications in borosilicate, alumino-borosilicate, and opal borosilicate glasses, totaling eight different installations. These applications have proven the benefits envisioned during the development. The technology originally used silicon carbide resistance heating elements, protected by an inert gas atmosphere, to heat the moly pipe. Design progressed to molybdenum resistance heating elements in which all moly parts were protected from oxidation by glass. The weakness of these designs was the short life of the heating elements. Failure of the molybdenum wire resistance heaters occurred in days or months in many cases. Induction heating was developed beginning in 1987 to replace moly wire heaters. After prototype trials, the first induction-heated MODES was installed in 1988 and the second in 1989. Both have met all performance requirements, with the promise of long life.