Sterilization principle of ultraviolet
UV sterilization is to destroy and change the DNA structure of microorganisms through UV irradiation, so that bacteria can die or not reproduce immediately, and achieve the purpose of sterilization. UVC ultraviolet is the real bactericidal effect, because the ultraviolet of C band is easily absorbed by the DNA of organism, especially the ultraviolet of 253.7nm is the best.
UV sterilization is a pure physical disinfection method, which has the advantages of simple and convenient, wide spectrum and high efficiency, no secondary pollution, easy management and automation. With the introduction of various new designed UV lamps, the application scope of UV sterilization is also expanding.
Structure of ultraviolet germicidal lamp
In fact, UV lamp is a kind of low-pressure mercury lamp. Like ordinary fluorescent lamp, it uses low-pressure mercury vapor (< 10-2Pa) to emit ultraviolet after being excited. The difference is that the fluorescent tube of the fluorescent lamp is made of ordinary glass. The ultraviolet light at 254 nm can't be penetrated, and can only be absorbed by the fluorescent powder on the inner wall of the lamp tube to excite the visible light. If we change the composition and proportion of the phosphor, it can emit different colors of light as we usually see. Generally, the tubes of germicidal lamps are made of quartz glass, because quartz glass has a very high transmittance to UV waves, up to 80% - 90%, which is the best material for germicidal lamps.
254nm ultraviolet rays kill bacteria by irradiating their DNA. This band has high energy. It can destroy the nucleic acid structure of microorganisms and has strong bactericidal effect, so as to achieve the goal of disinfection.