Source: Power-X

Desalination units of the multiple-effect type use the distillation process to produce fresh water

Multiple-Effect Desalination (MED) Plant

Desalination units of the multiple-effect type use the distillation process to produce fresh water. This technique was developed for its reliability and greatly eliminates the problems of filtration, corrosion, pretreatment and scaling.

MED units are manufactured in a range of standard outputs from 2,500 gallons per day and larger. These units are packaged up to 1,000,000 gallons per day depending on site transportation limitations.

Thus, multi-effect (MED) distillation offers a number of unparalleled advantages which will result in reduced investment as well as low operation and maintenance cost.


  • Low operating temperature limits scaling and corrosion.
  • Low energy consumption.
  • Production of high purity distillate.
  • Tolerance of high sea water salinity and temperature.
  • Tolerance of sea water chlorination and the bacteria contained in sea water.
  • Absence of sophisticated pretreatment of the incoming sea water, resulting in a low cost sea water intake.
  • Compact design allowing a skid-mounted concept which minimizes associated civil and site erection work.
  • Absence of brine recirculating pump.
  • Excellent flexibility of operation.
  • Resistance to hot and humid climate even in outdoor installations.
  • Simplified procedure for preservation when the units are shutdown for extended periods.

Heat input to the evaporator module can be achieved either by condensing low pressure-steam or by the circulation of hot water. The latter can be - for example - the cooling water of an engine or of a chemical process.

The evaporator produces, on request, a distilled water with a particularly low salinity, suitable for any industrial process requiring high purity water.

If the product water is intended for domestic use, very simple remineralization equipment is added.

These units are designed to treat water with a high salt content without requiring complex chemical pretreatment, which is difficult to handle and costly. The evaporator will operate well on any water to be treated - underground water, surface water, and sea water of medium (35 g/l) (35,000 ppm) or high salinity (55 g/l) (55,000 ppm).

Power-X, P.O. Box 8520, Stockton, CA 95206. Tel: 209-465-0296; Fax: 209-465-1605.