Views: 0 Author: Site Editor Publish Time: 2020-05-14 Origin: Site
Ultraviolet radiation (UV for short) is light radiation with a shorter wavelength than visible light, and ultraviolet rays in the wavelength range of 100 to 400 nanometers (nm) are generally divided into three categories:
1.UV-A (wavelength 315 ～ 400nm)
2.UV-B (wavelength 280 ～ 315nm)
3.UV-C (wavelength 100 ～ 280nm)
In the natural sunlight, UV-A accounts for about 98.1% and UV-B accounts for about 1.1%. UV-C is almost absent due to absorption by the ozone layer.
UV-A has a strong penetrating power, can pass through the ozone layer and clouds to reach the surface of the earth, regardless of whether it is cloudy or not, it stimulates the skin to generate free radicals, degrades collagen and elastin in the skin, and The skin melanin is calm, and the accumulation of skin will cause the skin to relax and darken.
UV-B has moderate penetration, and it is particularly strong in summer and afternoon, which causes skin redness and sunburn in a short time. Reasonable irradiation can promote the formation of mineral metabolism and vitamin D in the body, and promote bone development, but long-term or excessive exposure can cause skin redness and peeling. Most sunscreens on the market are used to protect against UV-B ultraviolet rays.
UV-C has the weakest penetration, and UV-C is absorbed by the ozone layer before reaching the ground in sunlight.
What is UV Sterilization?
The principle of UV Sterilization: Ultraviolet sterilization is the use of ultraviolet light of appropriate wavelength to destroy the molecular structure of DNA (deoxyribonucleic acid) or RNA (ribonucleic acid) in the cells of microorganisms, causing growth cell death and / or regenerative cell death to achieve sterilization.
Insect trap lights, graphite glue curing, ore identification, stage decoration, banknote verification
Plant growth lamp, ultraviolet health lamp, phototherapy, anti-counterfeiting identification
□Surface sterilization: UV surface sterilization devices are widely used in food, electronics, semiconductors, liquid crystal displays, plasma TVs, crystal vibrators, precision devices, chemicals, medicine, health care, biology, beverages, agriculture and other fields.
□Water treatment: Submerged and over-flow methods. Directly put the UV lamp into the water, called the submerged type; the UV lamp is used in the sleeve, called the over-flow type.
□Medical and health fields: static air direct irradiation method and flowing air disinfection method.
It should be pointed out that not all ultraviolet bands have inactivation functions against microorganisms. Among them, only ultraviolet rays in the UVC band in the range of 240 ~ 260nm are easily absorbed by bacteria and effectively act on the DNA of bacteria, interfering with their normal replication, resulting in The bacteria die, and UVA and UVB are outside the range of the microbial absorption peak, so the sterilization efficiency is very low, which belongs to the ultraviolet part that is not effective for disinfection.
What is UVC Led Sterilization?
The Advantages of UVC LED compared with traditional methods:
Compared with other sterilization methods such as chlorine, ozone and ultraviolet mercury lamp sterilization, UV LED disinfection has many advantages:
1. High-efficiency sterilization: The UVC segment of ultraviolet rays emitted by UV LEDs can kill bacteria and viruses within a few seconds. Traditional water sterilization methods such as chloride and ozone generally require 20 minutes to 1 hour to achieve sterilization.
2. Extensive sterilization: Because bacteria, virus antigens and other microorganisms are not resistant to ultraviolet light, so deep ultraviolet light can efficiently kill almost all bacteria and viruses, and ultraviolet LED sterilization technology can also It inhibits the growth of some higher aquatic organisms, such as algae, red insects, and paramecium.
3. Safe and environmentally friendly (without mercury): The most obvious advantage of UV LED devices over mercury-excited ultraviolet lamps on the market is that their sterilization light source does not contain mercury, and mercury is a heavy metal substance, commonly known as mercury, and mercury can be used at room temperature Evaporation, mercury vapor and mercury compounds are highly toxic (chronic). During the sterilization process of the traditional ultraviolet mercury lamp sterilization lamp, once the lamp tube is broken, it will cause serious water pollution, and the deep ultraviolet LED device is a safe and reliable device. No heavy metals, simple operation, safe and reliable operation
4. Small size, flexible design: Easy installation, UV LED device, small size, flexible sterilization device design, can be applied in the narrow space where traditional ultraviolet mercury lamp cannot
Analysis of UVC LED Application:
1. Water treatment disinfection and purification:
(1) Static water irradiation: In static water irradiation, there are two ways to improve the sterilization efficiency of UV LEDs: increase the irradiation time and increase the intensity of UV LED irradiation.
(2) Dynamic water irradiation: For dynamic water sterilization, the exposure time of ultraviolet LED to dynamic water is determined by the amount of water flow. In the case of a certain ultraviolet intensity, the greater the water flow, the shorter the irradiation time, the lower the radiation dose received by the bacteria and the worse the sterilization effect.
2. Air purification: As a new generation of green light source, UV LED provides an effective solution for air purification with its unique safety and economic advantages. The UV LED air sterilization and disinfection treatment system can also be used on any equipment that requires fresh and fresh air, such as air purifiers and refrigerators.
3. Food preservation(Surface disinfection): Without the use of other chemical reagents, only one UV LED can increase the freshness preservation ability of fresh vegetables and fruits at room temperature by 10-20 times, which greatly reduces the loss caused by decay.