PURPOSE: To prevent the crystallization of calcium carbonate as well as to raise the utilization rate of carbon dioxide in making drinking water by the method in which slaked lime is added to distilled water and then the distilled water is brought into contact with carbon dioxide to dissolve calcium carbonate and calcium bicarbonate in the distilled water.
CONSTITUTION: Distilled water containing slaked lime is introduced through the line 7 into the lower part of the bubbling tower 8 and also carbon dioxide gas is supplied through the porous material tube 10 from the line 9 into the lower part of the bubbling tower 8 while being dispersed in fine bubbles, where the slaked lime- containing distilled water and the carbon dioxide gas are flowed in parallel in the bubbling tower 8 so as to make a vapor-liquid contact, whereby slaked lime and carbon dioxide are reacted to form calcium carbonate and calcium bicarbonate. The water containing the calcium carbonate and calcium bicarbonate is drawn out of the upper part of the bubbling tower 8 through the line 12 to obtain a drinking water.
KUWABARA HARUO
OOTA KIYOMICHI
