Energy efficiency benchmarking of glass furnaces

Abstract

A method for a comparison of data on the specific energy consumption of a large set of glass melting furnaces is presented. This benchmarking of the energy efficiency levels takes the effect of the cullet fraction in the batch into account. The investigated energy consumption data, including electric boosting and oxygen consumption, are normalized to the primary energy equivalent (primary energy consumption of electricity and oxygen generation). A ranking of the energy efficiency of about 130 container glass furnaces has been derived. The difference in the specific energy consumption of the most energy efficient container glass furnaces and the furnace ranking the position 50% is only about 20 to 25%. The effect of furnace age, specific pull, total pull rate, type of furnace, cullet fraction and glass colour on energy consumption levels of container glass furnaces has been derived from a set of energy consumption data of more than 130 furnaces. From these data, the most energy efficient container glass furnace has been identified and a typical energy balance for such a furnace is given. Based on primary energy equivalent and 50 % cullet in the glass forming batch, the most energy efficient container glass furnaces show energy consumption levels close to 3.8 MJ/kg of molten glass. Results of a benchmarking analysis of the specific energy consumption of float glass furnaces are also presented. The energy consumption levels of these furnaces depend strongly on the size of the furnace, pull rate and furnace age, correlations for these factors have been derived.