Ultraviolet radiation sterilization principle 2013-3-7

A ultraviolet sterilization principle
Ultraviolet light is a kind of invisible to the naked eye light wave, in the spectrum of the purple ray, it is called the ultraviolet. Ultraviolet radiation from the sun is one of the electromagnetic wave, usually according to the wavelength uv fall into four categories as follows

Material is a kind of special form in operation, it is pointless unconnected particles. Every grain 253.7 nm wavelength of ultraviolet photons have 4.9 eV energy. When ultraviolet radiation to the microorganism, they happen energy transfer and accumulation, accumulated as a result of microbial inactivation, so as to achieve the purpose of disinfection. When bacteria, viruses absorb more than 3600 ~ 65000 uw/c ㎡ dose to bacteria, viruses to oxygen ribonucleic (DNA) and ribonucleic (RNA) with a strong destructive power, can make the bacteria, viruses lose viability and fecundity and destroy bacteria, viruses, achieve disinfection sterilization effect. Ultraviolet radiation on the one hand can make nucleic acid mutation, hinder its replication, transcription blockade and protein synthesis, On the other hand, generates free radicals can cause photoionization, leading to cell death.

Uv sterilizer sterilization principle is to use ultraviolet lamp irradiation intensity, namely ultraviolet germicidal lamp issued by the irradiation intensity, and the distance of the object as disinfection is inversely proportional. When irradiation intensity must, be as disinfection things stay the longer, the more close from sterilization tube, the sterilization effect is good, and the poor.

Two uv sterilizer classification

According to the different tube heat Yin level low pressure mercury vapour lamp, cathode low pressure mercury vapour lamp.

Thermal Yin level low pressure mercury vapour lamp from appearance can be divided into direct type, H type, U type pipe, etc.

In order to different needs, and can be divided into low (no ozone), ozone, high ozone etc.

Three sterilization efficiency

Ultraviolet disinfection technology with other technologies incomparable sterilization efficiency. Sterilization efficiency can reach 99% 99.9%. The table below lists ultraviolet technology on common several bacterial virus sterilization time typically require less than 1 second.

While the traditional chlorine, ozone and chemical disinfection methods to achieve ultraviolet C bactericidal effect of general need twenty minutes to 1 hour of time.

Table 1 ultraviolet C technology on common bacteria virus sterilization efficiency (ultraviolet radiation intensity: 30000 μ W/cm2)
Four use characteristics and range

Ultraviolet sterilizing instruments have flow uniformity, no dead Angle, light conditions are good, sterilizing thoroughly, low energy consumption, installation agile is convenient wait for a characteristic, the subject material made of stainless steel, no metal ion infection problem, the product structure is sealed container quartz sleeve type, with electric control device. The key of the UV lamp theory life up to 10000 hours, reached the international advanced level. Product appearance elegant appearance, compact structure, convenient operation and maintenance, widely used in industrial and mining enterprises, residents life, hotel hotel, organ school; A field army, food processing, pharmaceutical industry, high pure water preparation, public places or directly for drinking leisure travel and the water not allowed to have more chlorine beverage or other industries.

Five matters need attention

A uv germicidal lamp should pay attention to picture tubes according to the strength of the recession

Use after period of time, I doors tube still with fluorescent lamp concept to evaluate to visual visible light intensity to judge not visible light intensity, such methods appear easily error, and the sterilization effects. To judge from the following aspects

1 each kind of microorganism has its specific uv kill, death dose standard, and

K (sterilization dose) = I (irradiation intensity) X T (irradiation time)

From the formula, it is known that high strength short time and low intensity and long time effect is same, so tube after recession (using a long time later) should be extended sterilization time, ensure the quality of disinfection.

2 the ultraviolet penetration ability is not as imagination of the high, any scraps of paper, plastic, ordinary glass can greatly reduce the radiation intensity, so tube and glass casing should be kept clean (often use 75% alcohol to wipe, if the water hardness (calcium or magnesium) material, iron and manganese, then quartz tube need periodic cleaning. Cleaning quartz tube shall be put on the special plastic gloves will quartz tube carefully into the reactor, and put the seal to check for leakage phenomenon, plugged in, make sure to detect light stable luminous)

If you use the water quality is turbidity, turbidity was 5 degrees should add treated as flocculation, sedimentation, filtration, etc, for the removal of various impurities in water, or sterilization effect will sell at a discount greatly.

3 to choose material to pledge

Tube and casing should choose to natural crystal as the raw material of the quartz glass, its price, although longer than ordinary high borax glass your several times, but its ultraviolet penetration rate is more than 80% and high borax glass is less than 50%

So life not consider equipment outside, should choose quartz glass tube, casing for material

Two pay attention to protection

Rays of bacteria have great damage to the human body also has certain harm human body, the most easily injured parts is the eye cornea, so at any time, do not use the eyes look straight into the light of the lamp, in order to avoid injury, one thousand must be to see, the application of common glass (wear glasses) or light plastic film, as a protective mask. Do not misuse quartz glass, because ordinary glass to ultraviolet almost completely not through. Once hurt, don't panic, facial burn skin, after a few days off, not heal. Eye injuries will be red, tears, tingling, about three or four days to heal. However, a hurt, still recommend that seek medical advice immediately calls