August 2008 – In nearly all industrial sectors, from the food industry via the chemical-pharmaceutical industry up to the environmental industry evaporation plants are used for the concentration of the most different products.
The advantages of the separation of substances by means of evaporation are the reason for this variety of applications of evaporation plants. According to physical principles, one kilogram of heating steam is required to evaporator one kilogram of solvent. In times of increasing energy prices, this results in the fact that at first, evaporation plants are not interesting under economical aspects.
GEA Wiegand engineers have been facing this challenge during the past decades, and the result of their work is really impressive. Three recent examples shall illustrate this.
In Germany, a two-effect evaporation plant with mechanical vapour recompression for a capacity of 150 to/h was installed. Thanks to the energy-optimized design of the recompressors, annual savings of nearly 5,600 MW can be achieved.
The reconstruction of a five-effect evaporation plant in Indonesia from thermal to mechanical vapour recompression leads to savings of more than 34,00 MW.
The largest potential can be achieved, if – as realized in the Netherlands – a plant is heated by dryer vapour and is equipped with a mechanical vapour recompressor. With an evaporation rate of 24 to/h the energy consumption can be reduced by 42,600 MW. Converting these values to CO2 equivalents, this implies a reduction of up to 11,000 tons per year which is an important contribution to climate protection.