Evaporation plants using the ESCHER WYSS system have been built for more than 80 years. The first contract to supply a multistage compressor for mechanical vapour recompression in a salt plant dates back to the mid-twenties. Escher Wyss manufactured the compressors in their own workshops and were also asked to fabricate the evaporator for this plant which recovered salt from brine on a continuous basis. This project initiated Escher Wyss's activities in the field of evaporation technology and manufacture of the corresponding equipment.

The first salt plant was followed by contracts for further salt plants as well as evaporation plants for other liquors, known frequently as concentrators. The scope of supply was limited to the main vessels, which were assembled in our own workshops exclusively until the mid-fifties. By installing a circulation pump in the centre of the calandria type evaporator the forced circulation system was created. This evaporator became famous for its excellent heat transfer rates and salt slurry handling characteristics. The drive was mounted at the top of the vapour dome and connected by a shaft to the propeller in the base.

Experience grew from the widening range of applications in this special thermal separation technique. Through research and development new technologies were established and ESCHER WYSS was transformed from being a manufacturer of vessels into a contractor and supplier of technology and complete plants.

The implementation of this process technology and the associated equipment was characterised by its fast progress in developing new markets, for example, in the basic chemical industry, in the treatment of wastewater from flue gas scrubbers, to name only a few. In all these plants the design was based upon achieving optimum energy utilization whilst fulfilling the environmental requirements.

Evaporation plants based upon ESCHER WYSS technology were designed and supplied under the company names:

1924 – 1981 Escher Wyss
1981 – 1991 Sulzer-Escher Wyss
1992 – 1996 Sulzer Chemtech
1996 – 1999 CT Environment
1999 – 2000 VA TECH WABAG
2001 – 2004 Messo AG
Since 2004 GEA Messo AG

Since August, 2004 GEA Messo AG, has been incorporated in the GEA group, one of Europe largest technologies group. ESCHER WYSS evaporation and crystallization plants are now designed and supplied by GEA Messo AG.

In 1999 the well known Chloralkali Technology of KREBS SWISS Ltd. has been taken over and the wide range of different technologies incl. complete plants for the Chloralkali industry are now designed and supplied by GEA Messo AG. KREBS SWISS founded in 1946 by late Mr. Eduard C. Krebs was active as a company of chemical engineering consultants and process plant contractor of international reputation and one of the leading providers of the Chloralkali Technology.