The sterilization effect of the module depends on the dose of UV light. How to design a good sterilization module?
Dr. Meng Nan pointed out: UVC LED module design is ultimately the design of UV dose, and UVC dose is the key to the success or failure of the sterilization module.
Dose refers to the ultraviolet energy received by a unit area in a unit time. At present, 30 millijoules per square centimeter is the hard indicator of ultraviolet sterilization stipulated by the state. Irradiation time and irradiation intensity are two factors that affect the dose, which should be considered when designing the sterilization module.
For example, the UVC dose distribution of the water sterilization module, due to the different distances from the bottom LED light board, the water sterilization module receives different UV radiation doses. With the help of professional ray tracing tools, the radiation dose at different distances can be roughly known. For example, according to the characteristics of flowing water sterilization, the received radiation dose can be controlled by controlling the size of the structure.
Dr. Meng Nan said that under the premise that the overall cost of the sterilization module is relatively high, the simplest and most feasible way to increase the sterilization rate is to extend the LED lighting time, that is, the irradiation time. For example, on the premise of meeting the customer flow rate requirements, the water flow can be slightly slower by changing the module structure.
In terms of illumination intensity, LED is a point light source, and the light intensity distribution within its illumination range is usually concentric ring type. In addition, according to different illumination requirements, the LED light distribution structure must be adjusted accordingly. To treat them differently, it is also necessary to consider the absorption of space rays to reduce the loss of light energy.