Chapter 5. Operation of a Cullet Preheating System
- John B. Wachtman Jr
Published Online: 26 MAR 2008
Copyright © 1990 The American Ceramic Society, Inc.
Proceedings of the 50th Conference on Glass Problems: Ceramic Engineering and Science Proceedings, Volume 11, Issue 1,2
How to Cite
Cole, W. E., Becker, F., Donaldson, L. and Panahe, S. (1990) Operation of a Cullet Preheating System, in Proceedings of the 50th Conference on Glass Problems: Ceramic Engineering and Science Proceedings, Volume 11, Issue 1,2 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470312841.ch5
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 1990
Print ISBN: 9780470374894
Online ISBN: 9780470312841
- cullet fraction;
Tecogen Inc. has developed a gas-fired cullet preheater that will benefit glass manufacturers by increasing furnace production and reducing specific NOx emissions. In addition, compared to electric boost, energy costs can be reduced by over 20% for equivalent thermal inputs to the furnace, after accounting for electrical energy use of the preheater. The technology utilizes a direct-contact counterflow heat exchanger in which the cullet particles are heated by the products of combustion. Since the cullet enters the furnace at a temperature greater than ambient, less energy is required to raise the cullet temperature to its melting point, resulting in additional throughput at the same firing rate. Using 50% cullet preheated to 900°F, furnace production could typically be increased up to 17% over that available using unpreheated cullet. This number will vary depending on the furnace and type of glass. This increase in production will also yield a reduction in the specific NOx emissions. With a 50% preheated cullet throughput, a reduction in specific NOx emissions of approximately 16% can be expected. The payback of the cullet preheater varies typically from six months to two years.
This paper reports on the operation of the cullet preheater feeding cullet to a production flint glass container furnace. Furnace pull was 240 tons day (TPD); up to 80 TPD of cullet was preheated to 500°F and charged to the furnace. Furnace fossil energy use was reduced approximately 10% during the test period.