The units described are an extension of IDE's present range of MVC units of which more than 200 are operating world-wide in single and multi-effect configuration. The plants are available in capacities of up to 3,000 m3/d (0.8 mgd) in a single unit and up to 30,000 m3/d (8 mgd) in modular installations. The units consist of two or three evaporator-condenser effects coupled to a high volumetric compressor. The paper describes the development of large capacity high efficiency Mechanical Vapor Compression desalination units based on the low temperature distillation technology using the multi-effect, horizontal tube, falling film configuration. In addition to the increase in die individual capacity output, these MVC units have an improved operational performance with lower specific electrical consumption and minimal requirements for maintenance, manpower and chemical treatments. The combination of the economics of scale related to the increased units' size and the reduced operating costs associated with the lower utilities consumption, offer attractively low total water cost which compete with those of similar as well as alternative technologies. An additional advantage can be derived from the high purity of the product water (less than 5 ppm TDS). This allows the water to be used directly for industrial processes where boiler feed water quality is required or reduce further the production costs by blending the product with local brackish water and satisfy the potable water standards.
