DEVELOPMENT of its production techniques followed by close monitoring of energy consumption has enabled German glass producer Walther-Glas GmbH, in cooperation with heating specialists Kanthal AB, to record a 40 per cent reduction in consumption on its forehearth feeder systems.
Walther-Glas presses mainly domestic and all purpose glassware for the gift sector, and diffusing screens for automotive headlights.
It operates three production tanks each with a capacity of 24-30 tonnes a day. The forehearths convey molten glass at temperatures of 1450°C to processing machinery consisting of four sliding tables and twelve circular table presses. Processing temperature is around 1150°C.
In cooperation with Kanthal, Walther-Glas developed a forehearth channel system using Kanthal's Superthal flat panel heating modules to replace a conventional vertical heating system.
As a result, the heating area has been reduced by 55 per cent - an inner cross section of 100mm x 244mm is now sufficient whereas 250mm x 400mm was required previously.
The panels are rated at 5kW and are customised by Kanthal to a specified length and width. Rebuilding of the first new forehearth system was completed in three days, minimising production downtime.
An immediate effect on energy consumption has led to a reduction of 40 per cent from 63000kW/h per month to approximately 38000 kW/h. The ongoing benefit is that any general increase in energy charges is also reduced since the installed power and the peak values of power consumption are smaller.
It has also been found that, compared with conventional heating systems, a change of heating elements is rarely required. It is estimated that investment payback is around 15 months.
Not all of the benefits are cost related. Another result of the Kanthal system is that the ambient temperature of the forehearth is now lower by around 40°C to only 50°C. The smaller heat load in the area has improved working conditions.