BENCHMARK

Furnace Benchmarking means to compare the energy consumption of one furnace with that of others. The theory can be found in the papers written by Beerkens [1,2, etc]. glass global consulting decided to compare the specific energy consumption of a furnace with a normalised international average.

As every benchmark is only as good as the reference, large effort is spent to ensure an up to date data base of international furnace data. From the furnace data the specific energy consumption is normalised to the same cullet ration, inlet temperature of the media, electric boosting and furnace age by a self developed energy balancing software.

The software is able to consider complex relationships and adjusts furnace values like the fuel consumption, flue gas volumes, wall losses and more. Based on the normalisation, the results can be filtered by furnace type, glass type, combustion air preheating and type of oxidiser. The figure shows an example of a furnace benchmark.

Figure: Benchmark results of a glass melting furnaces

The green squares represent the normalised specific energy consumption of furnaces of the same type while the blue triangle represents the specific energy consumption of the customer's furnace. The dotted black line represents the interpolated specific energy consumption. All furnaces above the black line are requiring more energy than the international average. With a benchmark, underperforming furnaces can be identified quickly and easily and a rough estimation of the energy reduction potential could be made.

The table shows the data of a typical container and a float glass furnace are summarised and the saving potentials were estimated.

Of course, energy reductions can also be realised at furnaces performing better than the average. The profit increase, which can be reached in practice, depends on many factors. These are not included in the benchmark, especially factors related to economic issues, employee skills or product quality. Thus, the benchmark has to be seen as the first step in the process chain of furnace optimisation, and an on-site audit is indispensable.

However, a furnace benchmark is a perfect reference point for the following furnace optimisation.

For further information please contact our engineering team at consulting@glassglobal.com.