ULTRAVIOLET IRRADIATION DEVICE AND OPERATION METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To enable continuous operation over a long period of time by enhancing the output keeping ratio of ultraviolet rays of a discharge lamp for emitting ultraviolet rays with a region of 240 nm or less to achieve the conservation of maintenance and resources. SOLUTION: The ultraviolet irradiation device is equipped with the discharge lamp 30 having a light emitting tube 11 made of synthetic quartz glass and emitting ultraviolet rays with a region of 240 nm or less and a treatment device 1 for irradiating a continuously flowing liquid to be treated with ultraviolet rays emitted from the discharge lamp. A plurality of the discharge lamps are arranged in the treatment device and a predetermined number of the discharge lamps among the arranged discharge lamps are put out while the remainder is lighted and a combination of the discharge lamps put out and lighted is altered according to a temporal elapse.