Solvents are evaporated from solutions to obtain the desired product, to
recover certain substances or to reduce the volume. Such plants consist of a
variety of systems for evaporating solutions by heat input or vacuum
cooling.
During the planning phase of an evaporation plant for concentration various
systems are evaluated. The process design must be economic and take into
account energy savings as well as local conditions and the environment.
Choosing the appropriate system for an evaporation plant today often means that
important parameters are now viewed differently than in the past. Today,
fluctuating energy costs, difficulty in obtaining cooling water and the
stricter regulations concerning environmental protection are crucial factors.
GEA Messo AG has designed and supplied more than 400 process plants
worldwide. The extensive know-how that has been gained in realizing these
plants gives GEA Messo AG the depth of experience needed to design new plants
which are tailored to the client’s exact requirements and which minimise
investment and operating costs.
Characteristics of the Evaporation Processes
In the technology of evaporation two processes are mainly applied: The
multiple-effect and evaporation with thermo-compression. From time to time
combinations of these two processes are adopted. It has been found that,
despite its lower investment costs, the multiple-effect evaporation process
that previously predominated must nowadays be replaced in many cases by the
thermo-compression process.
Apart from the above mentioned processes and their combination, there are
also single-stage plants and special processes such as multiple-stage flash
evaporators. The various systems each have important characteristic features: