| 摘要 |
To ensure the maximum efficiency in the regeneration of the ion-exchange material used in the treatment of a liquid, e.g. water containing both salts of weak acids, e.g. bicarbonates and salts of strong acids, e.g. sulphates by an ion-exchange process operating on the hydrogen cycle, at least two cation exchange materials containing differing proportions of weakly acidic active exchange groupings, e.g. sulphonic are so associated that all the cations of the salts of weak acids will be exchanged for hydrogen ions on the weakly acidic groupings and the cations of the salts of strong acids will be exchanged for hydrogen ions on the strongly acidic groupings. Preferably, at least one cation exchange material contains a preponderance of weakly acid groupings and at least another contains a preponderance of strongly acidic groupings. At least one of the materials may contain groupings of substantially only one character. The overall ratio between the weakly acid groupings and the strongly acid groupings in the associated exchange materials should preferably be substantially the same as the ratio between the salts of weak acids and the salts of strong acids in the liquid to be treated. The materials may constitute a common bed or they may be distributed between two beds in a single vessel or in two vessels so as to be traversed in series by the liquid under treatment and so that substantially all the weakly acidic groupings are found in the bed encountered first by the liquid. In this latter case the volumes of the respective materials should preferably be such that the material in one bed will require regeneration in a period of time which is an integral multiple of the period of time at the end of which the material in the other bed will require regeneration. The Provisional Specification refers to Specification 450,308. |
