PROCESS FOR MAINTAINING HIGH OUTPUT OF LOW PRESSURE ULTRAVIOLET RAY LAMP USED IN ULTRAVIOLET RAY TREATMENT OF SERVICE WATER AND WASTE WATER AND LOW PRESSURE ULTRAVIOLET RAY LAMP THEREFOR

摘要

PURPOSE:To maintain the dose of short wavelength ultraviolet rays at high output level by controlling voltage and intensity of current to be supplied to a low pressure ultraviolet ray lamp basing on the detected temp. of the water to be treated at the lower temp. side than the peak value of the dose of a short wavelength ultraviolet ray lamp of low pressure. CONSTITUTION:A temp. detector 5 is provided to the inside of a treating tank 1 and connected to a temp. detecting unit 6 provided to the outside of the tank 1. The temp. in the treating tank 1 detected by the temp. detector 5 is used as the control signal for the temp. detecting unit 6 which is added to a dimmer device 7 provided to a low pressure mercury lamp 2. The voltage or intensity of current to be supplied to the low pressure mercury lamp 2 is controlled in the dimmer device 7 by the above described signal and is supplied to a lighting device 8 of the low pressure mercury lamp 2. The waste to be treated is fed at ca. 10-40 deg.C water temp. to the treating tank 1 in the above described water treating apparatus. On one hand, the operation of the low pressure mercury lamp 2 is preferred to be set to result 20-30 deg.C temp. as optimum temp.