More Efficient Forehearts

Performance of the forehearth is rated by the range of pull rates and gob temperatures within which the system is able to maintain an acceptable degree of homogeneity, the speed of response of the forehearth, and its ability to maintain temperature stability. Its roofblock shape, the number, the position and the size of exhausts, the degree of controllability of the combustion and cooling exhausts, and uniformity in temperature and viscosity distribution are important parameters in designing an efficient forehearth. In general, electric or new forehearths are more energy efficient than older models.

One efficient design is electric forehearth with indirect cooling. Heat is generated by electrodes in the glass melt while cooling is provided via indirect radiation by feeding cool air through the forehearth in ducts. Control systems regulate both the heating and cooling ((Worrell et al., 2008. p.71).

Development Status Products
Commercial
Glass

More Efficient ForeheartsCosts & Benefits

Parent Process: Conditioning and Forming
Energy Savings Potential

By installing the efficient design of forehearth, a plant in Norway was able to replace 3000 MWh/y natural gas consumption by 350 MWh/y of electricity consumption (~ 1078 MWh/y primary energy), providing an energy saving of 65% – in terms of primary energy (Worrell et al., 2008. p.71).

CO2 Emission Reduction Potential
Costs

In the Norwegian plant, installation of efficient forehearths required US $ 120 000 investment and provided annual savings of $ 95 000 – resulting in a payback time of 1.5 years [1987 values] (Worrell et al., 2008. p.71).

More Efficient Forehearts Publications

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