Research Of Microwave Electrodeless Ultraviolet Light Source And The Excitation Control

Ultraviolet light is widely used in all aspects of life and production as a kind of special light source. It can be carried out on the material surface, water and air disinfection and purification; also can be used to make corrosion resistant surface, age pigment, paint, etc. Using light oxidation of uv light source, can also decompose the harmful gas in air, medical water, etc. Traditional uv light source adopts the electrode stimulating way, make the material inside the light emit ultraviolet light, in this method, electrode is easy to be oxidized, service life of the lamp is short, less availability filler, the shape of light is single. Aiming at this situation, this article set out to study microwave uv light source, make its meet the demand of ultraviolet light, and greatly extend the service life, open up broad prospects for UV applications in various fields.In this paper, electrodeless uv lamp structure, internal metal type, content, and types of gas and air pressure in electrodeless lamp were studied, analyzed, and verified by experiments, in order to determine the appropriate type and quantity of metal materials in the lamp, as well as the inert gas filler types and pressure strength.In the case of fixed microwave power and frequency, to examine some of the parameters of the lamp, such as Ar pressure, the amount of mercury, the volume of the lamp’s influence on the spectral characteristics of light, lighting time and lighting temperature of wet lamp. Experiments show:when the Ar pressure inside the microwave electrodeless uv lamp, the amount of mercury in the lamp and the volume of the lamp increasing, the lamp’s ultraviolet light intensity and the total light intensity will increase. but ultraviolet light grabs the proportion of the total light intensity will decrease continuously. The lighting time of wet lamp will decrease, but it will extend when more than a certain value. The lamp’s volume increases and the amount of mercury increases, will reduce the lighting temperature of the lamp, the increase of Ar pressure can make the lamp’s lighting temperature rise. When the amount of mercury is5-20mg, inert gas content is1.5～40torr, the length of the lamp is110～160mm (u-shaped lamp is25mm in diameter), the lamp can light up in the water at room temperature.By the ultraviolet spectrum distribution experiment of microwave electrodeless uv lamp and high pressure mercury lamp, get the ultraviolet spectrum distribution data of them, we can see that microwave electrodeless uv lamp’s performance is better than that of high pressure mercury lamp, microwave electrodeless ultraviolet lamp’s uv light intensity at254nm is better than high pressure mercury lamp.At the same time of developing electrodeless uv lamp, in order to effectively stimulate the electrodeless uv lamp to work properly, adjust the intensity of uv light in a certain range, we developed a microwave power controller of adjustable output power, which provides guarantee for stimulating the electrodeless uv lamp intensity output effectively and getting different levels of ultraviolet light intensity.