摘要 |
PURPOSE:To permit the saving of chemicals used in desalination and regeneration by jointly providing an OH type strongly basic anionic exchange resin tower and an alkaline earth metal salt solution to a desalter of an outside-tower regeneration type, consisting of a desalting tower, a separating tower, an anion regenerating tower, and a mixing tower. CONSTITUTION:The OH type strongly basic anionic exchange resin tower 5 is separately provided to the desalter of an outside-tower regeneration type for condensed water, consisting of the desalting tower 1, the separating and cation regenerating tower 2, the anion regenerating tower 3, and the mixing tower 5, and the waste alkaline solution 7 for regenerating the anion regenerating tower is utilized for the resin present in the OH type strongly basic anionic exchange resin tower 5. Also, the alkaline earth metal salt aqueous solution 8 is passed through the OH type strongly basic anionic exchange resin 5 to convert it into an aqueous solution of hydroxide and then utilized for the anion regenerating tower 3 in order to eliminate the harmfulness by removing Na by converting a small amt. of cation exchange resin mixed in the aq. solution 8 to an alkaline earth ion type. Thus, chemicals can be compensated with each other and advantageously utilized, therefore the needs for fresh caustic soda can be eliminated. |