Multiple Effect Evaporators ( MEE ) designed and manufactured by Voice Engineers economize the consumption of energy. In MEE only first vessel requires the source of external heat.
This process involves continuous evaporation of solution by passing steam into it and condensation of vapour for recovery of useful water. For economizing the steam consumption, multiple units are used in series, each held at lower pressure than the preceding one , so that the vapour generated from one unit be used in the next effect for effecting the evaporation, thus eliminating the need for generation of fresh steam. This process is continued for a number effects, so that the every kg of steam generated for the first effect produces a number of kgs of vapour from the succeeding effects. Vapour from the last effect is condensed in a condenser using water from cooling tower. The entire plant is initially under vacuum, and thereafter the pressure in the entire system is thermodynamically stabilized. Vacuum is generated by using a suitable vacuum pump. The number of effects depends upon the capacity of the plant, so that optimized economy is achieved at minimum investment.
Depending upon the movement of feed from one effect to the next, there can be either Backward Feed Evaporators or the Forward feed Evaporators. Voice Engineers offer various types of evaporators, namely, Falling Film Evaporator, Rising Film Evaporator, Thin Film Evaporators and Forced Circulation Evaporators.