The Multiple-Effect Humidification (MEH) process for the extraction of water from salt-, brackish and well water represents a thermal method that is based on the well-known principle of evaporation (humidifier) and subsequent condensation (dehumidifier). The performance of this natural process was improved in the MEH process such that a major portion of the used evaporation energy remains within the process, permitting the low-temperature extraction of drinking water effectively and reasonably, without much waste heat, even in smaller units. The technical design of the process describes the natural water cycle, from evaporation (sea surface to atmosphere) to condensation (warm air in contact with cold air = rain). Thus, in a closed module, air is forced into circulation by a ventilator at atmospheric pressure. During its cycle inside the module, the air passes through the two main chambers of the system, the humidifier and the condenser, and it transports purest water (in gaseous form) from the humidifier to the condenser where it is retrieved as drinking water in liquid form. Through its various energy use options, the MEH is unique in terms of environmental sustainability. Due to the comparatively low operating temperatures, the energy required for such heating may be obtained as waste heat from operational processes or renewable energies, such as solar or geothermal power.

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