The operating costs of direct, steam-heated evaporators can significantly be reduced by revamping with mechanical vapor recompressors (MVRs), according to this company. For example, a four-effect, directly steam-heated evaporation plant, designed for 30 ton/h of water evaporation initially had a heating steam requirement of 8 ton/h of live steam. By revamping and heating with MVR, the energy demand could be reduced to 760 kW — an operating-cost savings of approximately €1.3 million/yr (based on prices of approx. €30/ton of steam and €0.1/kWh and about 8,000 h/yr operation). With an investment of less than €1.5 million, a return on sales after only 14 months is expected, says the company. This technology could be of interest for existing, as well for new evaporation plants. — GEA Wiegand GmbH, Ettlingen, Germany