The proportion of recycling cullets in hollow glass production in Germany is between 65% and 90%, depending on the produced glass colour. These recycled glass cullets are stored in the glassplants on open outdoor areas. Ice, snow and rainwater disrupt the production process significantly in winter and also increase energy consumption of the glass plant.
To use the waste heat potential in this case, hot air, with a temperature of 60 ° C, is extracted from the production hall above the melting furnace and energetically charged in a newly developed heat exchanger. The produced hot air with a temperature of 120 ° C can be used for a variety of purposes. In this application the hot air is used for the preconditioning of recycling cullets.
The goal of this preconditioning is defrosting, drying and preheating of the frozen glass cullets. For this preconditioning, an energy input of 200 kW, obtained from primary energy sources, is required without waste heat recovery. The newly developed technology saves this energy and avoids the corresponding amounts of exhaust gas. The described heat recovery system works with otherwise unused waste heat of the glass furnace.
Results / Benefit:
- CO2 reduction 334 tonnes p.a.
- Water reduction 166.5 ltr/h = 3,996 ltr./d
AND weather-related production troubles eliminated.