Membran cell electrolysis units with reduction of brine
By the membrane cell electrolysis method there is no additional or only a small enrichment of chloride in the process water respective swimming pool water, compared with standard units respectively continuous flow electrolysis units.

That enrichment of chloride at least corresponds to the quantity of chloride which is formed by the germ removal with chlorine gas. As is generally known hypochlorous acid and hydrochloric acid originates when reacting with water (Cl2 + H2O ? HOCl + HCl).

The water doesn’t become more aggressive by the dosage of a low-level alkaline-reacting NaOCl solution. So membrane cell electrolysis units with reduction of brine can be used in swimming pools without hesitation.

The chlorine content of the produced sodium hypochlorite is about 30 g/l. The stoichiometric reaction of chloride to active chlorine within the electrolysis unit and the high concentration of chlorine in the solution is possible because of the semipermeable membrane between the electrodes which is transparent only for sodium ions but not for chlorine ions.

This prevents the immediate reaction of the originating chlorine with sodium hydroxide (NaOH) to sodium hypochlorite (NaOCl).
So the unreacted brine can be kept in the circulation and returned to the process.

The brine will not be returned to the swimming pool water or to the water for products in the commercial and industrial field as with standard method. A salinization of the water doesn’t take place.

The interference of the arised gaseous chlorine into the sodium hydroxide (NaOH) solution happens after the electrolysis process, so that not until then the sodium hypochlorite (NaOCl) is generating.

The membrane cell process with brine circuit and respectively reduction of lean salt water is suitable for swimming pool technology, whose system components cannot tolerate a raised chloride content in the pool water.

The inserted salt is fully utilized by a stoichiometric reaction of the sodium chloride to free chlorine.
NaOCl-unit with a performance of 2,500 grams chlorine per hour (2,500 g chlorine/h)

The reactions are as follows:
in the electrolysis cell: 2 NaCl + 2 H2O <> 2 NaOH + H2 + Cl2
in the reaction chamber: 2 NaOH + Cl2 <> NaOCl + H2O + NaCl

Technical Data