Method for desalinating saline water, multi-effect distillation device and modular element suitable for multi-effect distillation device.

摘要

The invention relates to a method of desalinating salt-containing water by a single-effect or multiple-effect distillation process. The raw water (5) to be treated is successively fed to each effect in order to be at least partly evaporated by film evaporation in each effect at an essentially constant pressure level in each effect. Each effect comprises at least one channel system (12) having channels which have flow from top to bottom, which channels are heated and through which the raw water is passed in such a way that there is formed along the channel walls a film of raw water which at least partly evaporates during the passage through the channel system (12). The evaporation takes place stage-by-stage in each effect in an above-mentioned channel system for each stage and, between two successive stages, vapour formed in the first of said two successive stages is removed from the effect. The invention furthermore relates to an apparatus which is suitable for performing the method according to the invention. For this purpose, said apparatus is provided between two successive stages with removal means (13) for the interim removal of vapour from the effect between two successive stages. In this connection, each effect is accommodated in a process space which is sealed off essentially in a pressure-tight manner with respect to the environment. The multiple-effect distillation apparatus may at the same time be built up in a modular manner from one layer of modular elements (10) per stage.