| 摘要 |
PROBLEM TO BE SOLVED: To sufficiently sterilize liquid with ultraviolet rays even if the liquid has low ultraviolet transmittance.SOLUTION: In a liquid sterilization method where liquid is made to pass in front of an ultraviolet irradiator 11 and irradiated with ultraviolet rays to be sterilized, while the thickness of the liquid in a part irradiated with the ultraviolet rays is restricted so that the illuminance ratio of ultraviolet illuminance on the surface of the liquid to ultraviolet illuminance at the farthest point from the surface is 20% or more, the ultraviolet rays are irradiated at an irradiation intensity or for an irradiation time capable of obtaining the ultraviolet irradiation amount, reducing the survival rate of microorganisms to be sterilized to a predetermined value or less, in the part irradiated with the ultraviolet rays. |
