16 questions about the depth of UVC-LED disinfection
1. What is ultraviolet sterilization?
Ultraviolet sterilization is the use of appropriate wavelengths of ultraviolet light to destroy the molecular structure of DNA (deoxyribonucleic acid) or RNA (ribonucleic acid) in the cells of microorganisms, resulting in growth cell death and / or regenerative cell death. effect. Ultraviolet disinfection technology is based on modern epidemiology, medicine and photodynamics, and uses specially designed high-efficiency, high-strength and long-life UVC band ultraviolet light to irradiate flowing water to expose various bacteria, viruses, parasites, algae Other pathogens are killed directly.
2. The disinfection mechanism of ultraviolet sterilization
Studies have shown that ultraviolet rays mainly kill microorganisms by radiating damage to microorganisms (bacteria, viruses, spores and other pathogens) and destroying the function of nucleic acids, thereby achieving the purpose of disinfection. The action of ultraviolet rays on nucleic acids can lead to the breaking of bonds and chains, cross-strand crosslinking and the formation of photochemical products, etc., thereby changing the biological activity of DNA and preventing the microorganisms from replicating themselves. This ultraviolet damage is also a lethal damage.
3. The advantages of ultraviolet sterilization
a. The sterilization is fast and efficient. The sterilization of ultraviolet rays on bacteria and viruses can reach a sterilization rate of 99% -99.9% in one to two seconds, and can kill some bacteria (spores and viruses) that cannot be inactivated by chlorine disinfection It can also control some higher aquatic organisms such as algae and red insects to a certain extent;
b. Broad-spectrum sterilization. Ultraviolet technology has the highest sterilization broad-spectrum among all current disinfection technologies. It can kill almost all bacteria and viruses with high efficiency.
c. The integrated equipment is simple in structure, small and light, and takes up little space;
d. The operation and management are relatively safe, and there are basically no potential safety hazards caused by the use, transportation and storage of other chemicals that may be highly toxic, flammable, explosive and corrosive;
e. Completely silent.
4. Will the ultraviolet sterilization and disinfection products cause radiation or harm to the human body?
Our products are built-in chips, all work is done in a closed environment, the shell is metal packaging, there is absolutely no risk of leakage. In addition, our products have passed the UV leak test and are in full compliance with the National Health and Family Planning Commission's regulations on the hygiene and safety evaluation of printed and disinfected products.
5. Will drinking water sterilized by ultraviolet rays cause harm to human body?
Because the ultraviolet disinfection technology does not need to add any chemicals, it will not cause secondary pollution to water and the surrounding environment. Even if it is over-treated, it will not cause water quality problems. The physical and chemical properties of the water will remain basically the same. It will not increase the taste of the water and will not produce disinfection by-products such as trihalomethane.
6. Who is suitable for UV disinfection products?
Ultraviolet disinfection products are suitable for all people, especially those with poor resistance, such as the elderly, children, pregnant women, etc., to provide a higher quality of life. It is also very suitable for areas with high humidity, such as the rainy season in the south, the cost of tableware and tableware is prone to mold, and mold is not easy to clean and kill, which is easy to endanger human health.
7. Compared with other disinfection methods, what are the advantages of ultraviolet sterilization products?
a. A lot of germs need to be killed under certain temperature and a certain period of time. For example, the common hepatitis B virus needs to be killed for more than 20 minutes at 120 ° C or more. Therefore, boiling water and boiling and boiling can not completely kill germs. However, the ultraviolet disinfection method directly reaches the molecular structure of DNA or RNA in the cell, which can more efficiently achieve the disinfection and disinfection effect.
b. For example, traditional households will use cupboards to store tableware, but the traditional cupboards are not sealed or not well sealed, and will be subject to secondary pollution from dust, sewage, insects, ants, mice, etc. Secondly, traditional cupboards do not have a drying function and the humidity is relatively high. In high areas, the cost of wooden tableware is prone to mold, and aspergillus flavus in mold is a carcinogenic pathogen, and it is more difficult to kill, which poses a great hidden danger to human health. The use of ultraviolet sterilization products can sterilize any items that need sterilization anytime and anywhere.
8. The relationship between the power of ultraviolet sterilization and disinfection products and the effective disinfection area
4W small ultraviolet disinfection lamp, reliable disinfection space is 6 square meters of space, but because the space is small light will reflect, the sterilization effect will increase by about 50%.
12W is suitable for less than 20 square meters
30W is suitable for 20-35 square meters
40W is suitable for 30-45 square meters
9. Service life of ultraviolet lamp
10. The effective life of the hot cathode is 8000 hours, and the cold cathode is more than 20,000 hours
11. Material classification of ultraviolet sterilization products
The classification of ultraviolet sterilization lamp tubes: quartz glass tube, high borax glass tube, ordinary glass. The quartz glass tube material actually belongs to a low-pressure mercury lamp. Like ordinary fluorescent lamps, low-pressure mercury vapor (<10, 2pa) is used to emit ultraviolet rays after being excited. The tubes of general sterilization lamps are made of quartz glass, because quartz glass has a high transmittance of ultraviolet bands of 80% and 90%, which is the best material for sterilization lamps. Although quartz is relatively expensive, all mercury vapor lamps used for uv polymerization are made of quartz, and the material of the lamp cap is mostly bakelite, plastic or ceramic. The main reason is that quartz has three important properties that are very suitable for making UV lamps: (1) it is transparent to UV, does not absorb or rarely absorb UV; (2) is a poor conductor of heat; (3) the coefficient of thermal expansion is low, quartz The purity and the presence of other trace compounds will affect the emission characteristics of the lamp. The lamp tube is a fused silica tube.The thickness of the tube wall is about 1mm, the outer diameter is 20 ~ 25mm, the total length of the arc lamp is 2m, and the complex electrode layout (electron emitter, base, conductor, etc.) is sealed at both ends of the quartz tube The quartz tube contains mercury used to emit energy and a starting gas, usually argon. When the lamp is energized, an arc is generated between the two poles. As the voltage between the electrodes increases, the temperature of the gas rises, causing mercury to evaporate, producing mercury vapor arcs and emitting characteristic ultraviolet light. When working at full power, the lamp will also emit visible light and some infrared light. 2. The material of high borax glass tube is different due to the cost relationship and use, and the high borax glass tube with ultraviolet transmittance <50% can also be used to replace quartz glass. The production process of high boron glass is the same as energy-saving lamps, so the cost is very low, but its performance is far inferior to the ultraviolet sterilization lamp made of quartz glass tubes, and its sterilization effect is quite different. The ultraviolet light intensity of the high-boron tube is easily attenuated. After hundreds of hours of lighting, the ultraviolet light intensity drops to 50% and 70% of the initial value. While the quartz lamp is ignited for 2000 and 3000 hours, the UV intensity is only reduced to 80% and 70% of the original, and the light attenuation is much less than that of the high-boron lamp. 3. The ordinary glass material is a kind of ordinary glass with high ultraviolet light transmission, which is much higher than high boron glass and slightly lower than quartz glass. The light attenuation is still larger than that of quartz germicidal lamps, and it cannot produce ozone.
12. Will the human body be allergic to ultraviolet rays?
Ultraviolet allergy is allergy to the sun, because the skin is exposed to ultraviolet rays in the sun, which causes skin redness, itching and other abnormal reactions, resulting in skin allergies. In general, most people with ultraviolet allergies are allergic, so as long as the skin is exposed to a little sunlight, allergies may occur. The symptoms of ultraviolet allergy are mainly redness, burning, pain, itching, and erythema after sun exposure. The allergies are more serious, and even headache, fever, nausea, fatigue, and vomiting may occur. However, general ultraviolet sterilization and disinfection products will have a protective layer, which generally will not affect such people.
13. How does the ultraviolet germicidal lamp produce ozone
When ultraviolet rays are irradiated, uneven ions will be generated on the periphery of the rays, so that the oxygen molecules in the air can be ionized to recombine them into ozone
14. What is the difference between UV LED and UV mercury lamp
UV LED has the advantages of high efficiency, energy saving, environmental protection and long life:
High efficiency: ready to use, no need to preheat, can be set to light when the product passes;
Energy saving: The UV mercury lamp is a wide range of bands, and the curing or sterilization function is mainly one of the wavelengths. The other bands are useless and wasteful. They are absorbed by the product and converted into heat energy. This is also a product irradiated by the mercury lamp Will be higher than the temperature of LED irradiation. The LED is a single wavelength, for UV coatings, choose the matching LED wavelength curing; compared with traditional UV mercury lamps, UV LED can save 60% of energy;
Environmental protection: The mercury lamp contains mercury and other harmful substances, and the low-wave ultraviolet in the mercury lamp will react the oxygen in the air to ozone, which makes it necessary to install an exhaust exhaust system when using the mercury lamp, and the mercury lamp is low Ultraviolet radiation has a great radiation to people, and it needs to be completely sealed and shading. The LED has no noise pollution and chemical pollution to the environment, and no harm to the human body.
Lifespan: UVLED light source is a cold light source with a small amount of heat. The lifespan of LED is more than 20,000 hours, while the life of mercury lamp is about 1000 hours
15. The development history of UV LED
UV LED is ultraviolet light emitting diode. The core part of the light-emitting diode is a wafer composed of a P-type semiconductor and an N-type semiconductor. There is a transition layer between the P-type semiconductor and the N-type semiconductor, called a PN junction. In the PN junction of some semiconductor materials, the injected minority carriers and majority carriers will release excess energy in the form of light, thereby directly converting electrical energy into light energy. This kind of diode made by the principle of injection electroluminescence is called light-emitting diode, commonly known as LED. When it is in the forward working state (that is, the forward voltage is applied to both ends), when the current flows from the anode to the cathode of the LED, what is the history of the development of light emitting diodes in semiconductors?
In 1907, electroluminescence was first discovered by Henry Joseph Round on a piece of silicon carbide, but the light emitted was too dim and the difficulties in the experiment of silicon carbide at the time did not continue to study.
In 1920, German physicists Bernard Gooden and Robert Wichard Pohl obtained phosphorus materials from copper-doped zinc sulfide, and further carried out experiments, but in the end, the light emitted was too dim and stopped again.
In 1936, George Destriau published a report on the luminescence of zinc sulfide powder, and it was widely believed that he coined the term "electroluminescence".
In 1950, British scientists used gallium arsenide to create the first "modern" light-emitting diode in early 1960, and the first commercial diode was produced in 1960. LED is the abbreviation of English light emitting diode (light emitting diode). Its basic structure is a piece of electroluminescent semiconductor material, placed on a leaded rack, and then sealed with epoxy resin around it to protect the internal core wire. Function, so the seismic performance of LED is good.
In the middle of 1970, gallium phosphide itself was used as a luminous body and quickly emitted a very pale green light. The light-emitting diode uses a double gallium phosphide chip to be able to emit yellow light. Yellow light-emitting diodes were probably manufactured by the Russians using silicon carbide at this time.
In the mid-1980s, gallium aluminum phosphorous arsenide was used to make the first generation of super bright LEDs, first red light, then yellow light and finally green light.
In the early 1990s, indium gallium aluminum phosphorous was used to produce ultra-bright light-emitting diodes that could emit orange-red light, orange light, yellow light and green light. The first blue light-emitting diode was also manufactured using silicon carbide in 1990
It was only in the mid-1990s that GaN was used to make ultra-bright blue light-emitting diodes, and then indium gallium nitride was soon used to make high-intensity green and blue light-emitting diodes. The ultra-bright blue chip is the basis of white light-emitting diodes. The light-emitting chip uses a fluorescent phosphor coating that absorbs blue light and emits it as white light. Finally, always use the same technology to create any color
16. So what are the main features of UVLED as a light-emitting diode?
a. There is no or very little organic solvent volatilization, UV is cured by UV light source, and the UV light source does not contain mercury, which is an environmentally friendly product;
b. The UV LED curing system does not generate heat. The UV LED technology can significantly reduce the heat generated during the curing process, so that people can perform UV printing on thin plastics and other materials;
c. UV LED curing technology can also reduce the two-way drag phenomenon during the curing process. In general, LED curing technology can not only simplify the printing process, but also enable those end users who do not have knowledge of screen printing to get the ideal printing effect;
d. Since the ultraviolet light emitted by the UV LED can immediately cure the ink, the drying time required by other technologies is saved, and the production efficiency is greatly improved;
e. Suitable for a variety of substrates: flexible or rigid, absorbable non-absorbent materials;
f. Energy saving and cost reduction, UV light source also has a variety of advanced functions and environmental protection. Compared with traditional metal halide lamps, UVLED can save 2/3 of the energy. The service life of LED chips is many times that of traditional UV lamps Another important advantage of the technology is that UVLED does not need to be preheated and can be turned on or off at any time as needed.