Electrodialysis unit for water treatment

Abstract

An electrodialysis unit 8 comprises a plurality of cathodes 68, a plurality of anodes 70 and a plurality of membranes 71; the cathodes 68 and anodes 70 being arranged alternately in an electrode stack, with membranes 71 in between each cathode 68 and anode 70, anode flow paths 74 formed between the membranes 71 and anodes 70 and cathode flow paths 72 formed between the membranes 71 and cathodes 68; the electrodialysis unit 8 further comprising: an inlet manifold 56 for distributing water to the anode flow paths 74 or to the cathode flow paths 72, wherein the inlet manifold 56 comprises a first tube 58 provided with holes along its length, the holes being connected to the flow paths, and a second tube 60 located within and enclosed by the first tube 58, the second tube 60 having an inlet at one end and being closed at its second end and the second tube 60 being provided with holes 62 along its length that open into the first tube 58.

Description

Technical field

[0001] The present invention relates to water treatment by electrodialysis, such as treatment to kill microorganisms, preferably seawater treatment, such as ballast water treatment. Background technique

[0002] Ballast water is water transported by ships in ballast tanks or sometimes in other suitable spaces, such as cargo holds or oil tanks. Pump it into the tank at the location of the water "donor" to compensate for the change in the center of gravity caused by the unloading / consumption of cargo and / or fuel, and thus maintain stability. Correct ballasting is necessary from a structural point of view, and is also used for performance reasons to ensure proper thruster and rudder immersion, proper bridge considerations, and maintain desired ship movement and operating characteristics. Ballast water is transported to a water "holding" location, which is usually at the location where the ship loads cargo, which is potentially outside the biogeographic area of ​​the...

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