Quickly Understand The Working Principle Of Ultraviolet Ozone Lamp

The principle of ultraviolet sterilization lamp is the same as that of fluorescent lamp and energy-saving lamp. The mercury atom in the lamp tube is excited to produce the characteristic spectral line of mercury. [instantaneous high-voltage breakdown of mercury vapor, making it a conductive ionization state and emitting light.] Low pressure mercury vapor mainly produces 254 nm and 185 nm ultraviolet rays.

Fluorescent lamps and energy-saving lamps are made of ordinary glass, and the tube wall is coated with phosphor. Ultraviolet rays cannot be penetrated, and they emit visible light after being absorbed by phosphor;

The sterilization lamp tube is made of purple money glass or quartz glass. Ultraviolet rays are transmitted through the glass tube wall.

Ultraviolet light with the wavelength of 254 nm is easily absorbed by organisms and acts on the genetic material DNA of organisms, causing DNA damage and bacterial death.

Ultraviolet rays with a wavelength of 200 ~ 290nm can penetrate the cell membrane of bacteria and viruses, damage nucleic acid (DNA), make cells lose their reproductive ability and achieve the effect of rapid sterilization. Short wavelength ultraviolet rays with wavelengths below 200 nm can decompose O2 molecules, and the generated o * combines with O2 to produce ozone O3. Ozone has a strong ability to decompose and oxidize organic odor molecules, including UV / O3.

The 185nm ultraviolet ray can produce ozone with strong oxidation effect by interacting with air, which can effectively kill bacteria.

The reason why the ultraviolet sterilization lamp produces ozone is that the short wavelength ultraviolet with a wavelength below 200nm can decompose o Ω molecules, and the generated o * is combined with O Ω to produce ozone o ₃. The specific reaction process is as follows.

3O Ω + HV = 2O З, where HV is the appropriate wavelength energy.

Ultraviolet light is light with a wavelength of 10 ~ 400 nm in sunlight. It can be divided into UVA (ultraviolet A, wavelength 320 ~ 400 nm, long wave), UVB (wavelength 280 ~ 320 nm, medium wave) and UVC (wavelength 100 ~ 280 nm, short wave).

Only when the wavelength of ultraviolet light is no more than 200 nm can it be absorbed by O Ω in the air, resulting in reaction to produce o З.

UV band category

Ultraviolet rays can be divided into near ultraviolet UVA, far ultraviolet UVB and ultrashort ultraviolet UVC.

(1) Short wave UVC

Short wave ultraviolet (UVC) is ultraviolet light with a wavelength of 200 ~ 280nm (nm). Short wave ultraviolet rays are absorbed by the ozone layer when passing through the stratosphere of the earth's surface and cannot reach the earth's surface. The destructive power of short wave ultraviolet rays to microorganisms is extremely strong. When the ultraviolet rays of this band irradiate the bacterial body, the nuclear protein and deoxyribonucleic acid (DNA) of the cell strongly absorb the energy of this band, and the chain between them is opened and broken, resulting in the death of bacteria. For example, ultraviolet mercury lamp or metal halide lamp is used to sterilize air and food.

Ozone can absorb ultraviolet rays, because its molecular structure makes it resonate with ultraviolet rays of a certain energy. Strictly speaking, the energy of ultraviolet rays is also in a certain range. Ozone is good at absorbing only a specific part of it. However, the part it absorbs happens to be the "killer" who is prone to skin cancer.

In fact, such resonance is common for many kinds of molecules, but the absorbed electromagnetic waves are different. Molecules absorb electromagnetic waves mainly from a physical phenomenon called "resonance". For example, we used to say that when large troops walk across a bridge, they must not walk in unison, because they are afraid of the vibration of the step and the inherent vibration of the bridge (the vibration always exists objectively, but some weak ones are difficult for us to feel, but the instrument can measure them.) "Superposition" intensifies the bridge vibration and leads to collapse. This is a common "resonance" phenomenon. Similarly, the internal motion of molecules also has "vibration" equivalent to different energy levels. When the external energy (such as the electromagnetic wave of a specific energy) is exactly equal to the energy difference between two different energy levels, the molecules will absorb the external energy, which is the "resonance" at the atomic atomic level.

(2) Medium wave UVB

UVB, short for UVB, is ultraviolet with a wavelength of 280 ~ 320nm. UVB has certain physiological effects on human skin. A large part of such ultraviolet rays are absorbed by the skin epidermis and cannot penetrate into the skin. However, due to its high energy level, it can cause strong light damage to the skin, dilate the dermal blood vessels at the irradiated part, and the skin can have symptoms such as redness, swelling, blisters and so on.

Long term irradiation of the skin will cause erythema, inflammation and skin aging. In severe cases, it can cause skin cancer. Therefore, UVB, also known as the sunburn (red) section of ultraviolet, is the ultraviolet band that should be focused on prevention.

(3) Long wave UVA

UVA is ultraviolet with a wavelength of 315 ~ 400nm. The penetration of UVA to clothing and human skin is much stronger than UVA. It can reach the depth of dermis and act on the melanin in the epidermis, so as to cause skin melanin deposition and darken the skin, which plays a role in defending ultraviolet rays and protecting the skin.

Positive effect of ultraviolet light

(1) Sterilization

Ultraviolet sterilization: short wave ultraviolet rays have strong destructive power on microorganisms. When the ultraviolet rays of this band irradiate the bacterial body, the nuclear protein and deoxyribonucleic acid (DNA) of the cell strongly absorb the energy of this band, and the chain between them is opened and broken, so as to kill the bacteria. For example, ultraviolet mercury lamp or metal halide lamp is used to sterilize air and food.

(2) Health care function

After the human body is irradiated with monthly ultraviolet rays with the wavelength of 280 ~ 320 nm, it can cause the photochemical process and photoelectric reaction of the skin and body, and make the skin produce many active substances, so as to play the role of health care. Ultraviolet radiation is used to regulate the function of advanced nerves, improve sleep and reduce blood pressure. Regular exposure to ultraviolet radiation can strengthen the phagocytosis of white blood cells and enhance human immune function.

(3) Decompose organic matter

Adding (or coating) a small amount of nano titanium dioxide powder on the surface of building materials or household appliance materials can adsorb VOC (such as formaldehyde, benzene, toluene, ethanol, chloroform, etc.), which can be decomposed after ultraviolet irradiation.