February 2006 - Evaporator operating costs are largely determined by energy
consumption.
Over time, the means of reducing these costs has led from
multiple-effect arrangements and the application of thermal vapour
recompression (TVR), to the use of mechanical vapour recompression (MVR).
GEA Wiegand is leading in this technology, which they have impressively
shown just recently by successfully commissioning a plant for the production of
Marmite at Unilever UK’s site in Burton-upon-Trent.
Autolysed brewer's yeast extract had previously been concentrated from 6 to
45 % TS using two steam heated, 3- and 5-effect evaporators - one of which
having originally been supplied by GEA Wiegand in 1957 and still in daily use!
GEA Wiegand has now replaced these plants with a state-of-the-art,
single-effect evaporator using the highly efficient mechanical vapour
recompression technology.
A high-pressure fan recompresses the flashed vapours so as to reuse them for
heating, thus dramatically reducing the energy costs.