Apparatus for improving city water

摘要

The present invention lies in a method of improving a Langelier index and pH of city water wherein undissolved matter (calcium carbonate and slaked lime covered with calcium carbonate) slurry produced in a slaked lime dissolving vessel is mixed and reacted with carbonic acid-containing water in a mixing and reacting vessel to make a calcium hydrogen carbonate aqueous solution so as to continuously add to water in a water-receiving vessel together with a slaked lime aqueous solution, with which a utilization percentage of undissolved matter which has hitherto had a low utilization percentage is increased, and the Langelier index can be improved.