Summary

The energy in the flue gases from glass furnaces is often not explored. Heye-Glas in Moerdijk has executed a project that demonstrates the efficient use of energy out of the hot flue gases (appr. 1450 °C).
The flue gases pass through a steam boiler and the generated steam drives two turbines. Air blowers are connected to the shafts of these turbines and supply air to the hollow glass machines. The remaining heat is used for preheating broken glass material that is used as input raw material for the glass furnaces.
The energy conservation reaches 746,000 Nm³ natural gas equivalent.
The investment in boiler, turbines and other apparatus amounts to € 590,000.
The economic benefits in energy saving are € 107,000. Conversely the maintenance costs are raised by approximately € 2,300 pro year. Conclusively the pay-back period is 6.2 year. However, taking into account the recommendations and learning's, the pay-back period can be shortened to 3.5 years in future cases.