GB806445A - Improvements in or relating to the treatment of distilled water - Google Patents

Abstract

Distilled water is rendered more palatable and non-corrosive to metal by chlorinating the water, introducing temporary hardness into the water and subsequently dechlorinating the water. The chlorination may be effected prior to or subsequent to the introduction of temporary hardness, employing sodium hypochlorite solution as the chlorinating agent, while the dechlorination may be effected by passage of the water through a bed of activated carbon. The temporary hardness may be introduced into the water by passage through a bed of calcium carbonate (e.g. limestone chippings) in the presence of dissolved carbon dioxide. The carbon dioxide may be extraneously introduced or may result through the use of sea-water, containing magnesium and calcium bicarbonates, as the raw water which is distilled. The taste of the water may be improved by dissolving air therein before or after the treatment. Alternatively, the air may be introduced during the treatment by admitting the water into the air space in the vessel containing the bed of activated carbon in the form of a spray, and also supplying compressed air to the air space, so that air is dissolved in the water. Means may be provided for periodically reversing the flow of water through the bed of activated carbon, or through the beds of activated carbon and calcium carbonate. Means may also be provided for sterilising and reactivating the carbon bed by periodic injection of steam. Apparatus for carrying out the process of the invention is described. Specification 801,011 is referred to.