Glass, Ceramic frits and Glazes

Continuous analysis of O₂% in regenerative / recuperative melting furnaces is essential to ensure the overall performance of the melting process. This analysis guarantees a defined oxidizing atmosphere that allows the quality of the product to be controlled, solving the appearance of quality defects such as the appearance of bubbles and infusions. It also avoids the existence of high concentrations of CO₂, unburned as well as possible structural damage to the furnace refractory.

A good regulation of the air / fuel ratio and its balance with the internal pressure of the oven can reduce O₂% in ranges from 1% to 2%, which implies standard savings of 3% to 4% of fuel.

On the other hand, the amount of CO₂ emissions produced depends, among other factors, on the excess air introduced into the combustion process. It is estimated that for every 1% reduction in the flow of unburnt gases through the furnace, the reduction in CO₂ emissions from combustion will be around 2% - 3%. Furthermore, reducing NOx emissions below allowable levels (500 mg / Nm3) requires O₂% levels below 1.5%.

In those furnaces with gas / O₂ burners, the control of the oxidation level of the furnace atmosphere allows a finer adjustment to be made in the combustion O₂ and fuel consumptions. In addition, in plants with their own O₂ production, there are frequent variations in its purity (90% - 95%), making the continuous control of the combustion atmosphere even more crucial.

In general, a melting furnace without continuous control of the combustion atmosphere generates:

• Greater fuel consumption
• Structural damage to the furnace refractory
• Possible problems in the quality of the final product (bubbling, shades, etc.).
• Greater contamination (CO₂, CO, unburned, etc.).