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Improved Refractories and Insulation

Furnace insulation material, which reduces heat losses by about 55 to 65%, may have problems including higher corrosion rates and and "rat holes" in the silica crown. Over the life cycle of the campaign the heat losses increase as the insulation material wears off. It is estimated that deteriorating refractories may lead to increasing energy losses of 0.1- 0.2%/month – put differently, energy use at the end of campaign life may be as much as 20% higher than at the beginning due to refractory deterioration (Worrell et al., 2008. p.20). The heat losses from the silica crown are about 5% of the total heat loss in a glass-melting furnace. New refractories are being developed that demonstrate a better resistance to the aggressive environment in the glass tank, increase lifetime (and hence campaign life) while providing improved insulation over the campaign life. There are ongoing R&D efforts to develop improved refractories for different glass compositions. Heat exchange intensity of the regenerator can also be increased by replacing the refractory bricks in the regenerator by specially shaped fusion materials. To be economic, any changes in the insulation of an existing furnace should be considered at the time of furnace design, or at the end of the campaign life when rebuilding a furnace. 

One such refractory material with higher efficiency and longer service life is offered by Lubislov Engineering Co., whose crown insulation reportedly uses a high quality silica refractory and eliminates loose joints to avoid negative effects on the furnace. Another company based in Sweden (Kanthal AB) has developed heating elements with fiber insulation in complete modules that have demonstrated energy savings, increased pot furnace life, and improved product quality and flexibility (Worrell et al., 2008. p.61)

Development Status Products

Improved Refractories and InsulationCosts & Benefits

Parent Process: Melting and Refining
Energy Savings Potential

According to one advanced refractory material producer, their products can reduce the fuel budget by 1 – 1.5% with upgrading the crown insulation, and by up to 4.5% when the crown insulation is newly applied (Worrell et al., 2008. p.61).

Typical energy savings of about 7% can be achieved by replacing refractory bricks in the regenerator by specially shaped fusion materials ((Worrell et al., 2008. p.61).

CO2 Emission Reduction Potential


Quantitative information not available. 


Quantitative information not available. 

Improved Refractories and Insulation Publications

Page Number: 

20, 61