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The desalination process of MED-TVC (Multi Effect Desalination With Thermal Vapour Compression) is based on evaporation and condensation of  sea water under a high vacuum, this process takes place in some evaporators. These evaporators are often called effects or cells.

Sea water is spread as thin film over the horizontal tubes installed inside the evaporators. This water is evaporated by heat transferred from the steam passing inside the tubes. The vapour inside the tubes transfers its thermal energy to sea water and is condensed. The evaporated sea water is then passed through demisters, to prevent carryover of salt. The pure steam then moves to the next effect and transfers heat to the sea water. The generated vapour in this effect is condensed inside the next effect tubes. The product water in each effect (distillate) is cumulated with the subsequent effects’ distillate water. This process continues till the last effect.

The vapour generated in the last effect is divided in two parts:

A portion of it is sucked by thermocompressor because of a supersonic nozzle on it and after mixing with the motive steam enters the first effect tubes.
Using the thermocompressor decrease the amount of energy consumption by recycling a part of steam inside the system.

The other portion of it enters the condenser and is distillated by the inlet water passing through the condenser tubes.

Increasing the number of effects results in more distilled water produced for constant heat energy consumption. Also less sea water and steam is used by increasing the number of effects

The proposed desalination unit mainly consists of 4 effects, a condenser and a thermo compressor, which is a large recycling steam ejector to recover a portion of last effect produced vapour energy that is going to be removed in condenser.

Process Flow Lines
1- Inlet steam to the desalination unit
2- Sea water flow
3- Product water and condensate water
4- Brine flow
5- Non condensable Gasses (NCG) flow