Electrodialyser with superimposed alternate cells - for desalination and effluent enrichment contains square membranes

摘要

The two sets of cells are piped in independent circuits and connected electrically in series to a power supply. Each cell has opposed cationic and anionic membranes the direction of hydraulic flow through the desalination cells crosses the direction of flow through the enrichment cells, pref. at right angles. Both cationic and anionic membranes are pref. square and of the same surface area. Each pile of cells comprises spacer frames between each pair of membranes. The frames are square and of the same size as the membranes. Each membrane has a set of flow passage perforations along each of its four edges. Each spacer frame has a set of flow passage perforations along two opposed edges only. The other two opposed edges of the same frame are much narrower in order to allow flow between adjacent membranes and the frame flow space. The electrodialyser is for the desalination of seawater etc., e.g. for the prodn. of drinking water. The elimination of divergent and convergent, diffuser passages at the flow entry and exit of the frame spaces of previous rectangular section cells increases the effective surface area of the membranes. This in turn, enhances the output capacity of the dialyser.