Ceev kom nkag siab txog Txoj Cai Ua Haujlwm ntawm Ultraviolet Ozone Teeb
Feb 23, 2022
Lub hauv paus ntsiab lus ntawm ultraviolet sterilization teeb yog tib yam li lub teeb fluorescent thiab lub zog- txuag teeb. Lub mercury atom nyob rau hauv lub teeb raj yog zoo siab los tsim cov yam ntxwv spectral kab ntawm mercury. instantaneous high-voltage breakdown of mercury vapor, ua rau lub xeev conductive ionization thiab emitting lub teeb. Tsawg siab mercury vapor feem ntau tsim 254 nm thiab 185 nm ultraviolet rays.
Fluorescent teeb thiab lub zog- txuag lub teeb yog ua los ntawm cov iav zoo tib yam, thiab lub raj phab ntsa yog coated nrog phosphor. Ultraviolet rays tsis tuaj yeem nkag mus, thiab lawv tawm lub teeb pom kev tom qab tau nqus los ntawm phosphor;
Lub sterilization teeb lub raj yog ua los ntawm ntshav nyiaj iav los yog quartz iav. Ultraviolet rays kis tau los ntawm lub iav raj phab ntsa.
Ultraviolet lub teeb nrog lub wavelength ntawm 254 nm tau yooj yim nqus los ntawm cov kab mob thiab ua rau cov khoom siv caj ces DNA ntawm cov kab mob, ua rau DNA puas thiab cov kab mob tuag.
Ultraviolet rays nrog lub wavelength ntawm 200 290nm tuaj yeem nkag mus rau hauv cov cell membrane ntawm cov kab mob thiab cov kab mob, kev puas tsuaj rau nucleic acid (DNA), ua rau cov hlwb plam lawv lub peev xwm ua me nyuam thiab ua tiav cov txiaj ntsig ntawm kev ua kom tsis muaj menyuam sai. Luv wavelength ultraviolet rays nrog wavelengths hauv qab 200 nm tuaj yeem decompose O2 molecules, thiab cov generated o ua ke nrog O2 los tsim ozone O3. Ozone muaj peev xwm ua kom decompose thiab oxidize organic tsw molecules, suav nrog UV / O3.
185nm ultraviolet rays tuaj yeem tsim ozone nrog cov nyhuv oxidation muaj zog los ntawm kev cuam tshuam nrog huab cua, uas tuaj yeem tua cov kab mob zoo.
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 plus HV = 2O З, where HV is the appropriate wavelength energy.
Ultraviolet lub teeb yog lub teeb nrog lub wavelength ntawm 10 400 nm nyob rau hauv tshav ntuj. Nws tuaj yeem muab faib ua UVA (ultraviolet A, wavelength 320 400 nm, yoj ntev), UVB (wavelength 280 320 nm, nruab nrab yoj) thiab UVC (wavelength 100 280 nm, luv yoj).
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 qeb
Ultraviolet rays tuaj yeem muab faib ua ze ntawm ultraviolet UVA, deb ultraviolet UVB thiab 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) Nruab nrab yoj UVB
UVB, luv luv rau UVB, yog ultraviolet nrog lub wavelength ntawm 280 320nm. UVB muaj qee yam cuam tshuam rau tib neeg cov tawv nqaij. Ib feem loj ntawm cov hluav taws xob ultraviolet yog absorbed los ntawm daim tawv nqaij epidermis thiab tsis tuaj yeem nkag mus rau hauv daim tawv nqaij. Txawm li cas los xij, vim nws lub zog siab, nws tuaj yeem ua rau lub teeb muaj zog rau ntawm daim tawv nqaij, nthuav tawm cov hlab ntsha ntawm cov hlab ntsha ntawm qhov irradiated, thiab daim tawv nqaij tuaj yeem muaj cov tsos mob xws li liab, o, hlwv thiab lwm yam.
Lub sij hawm ntev irradiation ntawm daim tawv nqaij yuav ua rau erythema, o thiab tawv nqaij laus. Thaum mob hnyav, nws tuaj yeem ua rau mob qog noj ntshav. Yog li ntawd, UVB, tseem hu ua sunburn (liab) seem ntawm ultraviolet, yog ultraviolet band uas yuav tsum tau tsom rau kev tiv thaiv.
(3) Ntev yoj UVA
UVA yog ultraviolet nrog lub wavelength ntawm 315 400nm. Kev nkag mus ntawm UVA rau khaub ncaws thiab tib neeg cov tawv nqaij muaj zog dua li UVA. Nws tuaj yeem ncav cuag qhov tob ntawm dermis thiab ua rau melanin nyob rau hauv lub epidermis, thiaj li ua rau cov tawv nqaij melanin deposition thiab darken ntawm daim tawv nqaij, uas plays lub luag hauj lwm nyob rau hauv tiv thaiv ultraviolet rays thiab tiv thaiv daim tawv nqaij.
Cov nyhuv zoo ntawm ultraviolet lub teeb
(1) Sterilization
Ultraviolet sterilization: luv yoj ultraviolet rays muaj zog puas tsuaj rau cov kab mob. Thaum cov kab hluav taws xob ultraviolet ntawm cov kab no irradiate cov kab mob hauv lub cev, cov protein ntau thiab deoxyribonucleic acid (DNA) ntawm lub xov tooj ntawm tes txhawb nqa lub zog ntawm cov kab no, thiab cov saw hlau ntawm lawv qhib thiab tawg, thiaj li tua cov kab mob. Piv txwv li, ultraviolet mercury teeb lossis hlau halide teeb yog siv los ua kom tsis muaj cua thiab khoom noj.
(2) Kev saib xyuas kev noj qab haus huv muaj nuj nqi
Tom qab tib neeg lub cev yog irradiated nrog lub hli ultraviolet rays nrog lub wavelength ntawm 280 320 nm, nws tuaj yeem ua rau cov txheej txheem photochemical thiab photoelectric cov tshuaj tiv thaiv ntawm daim tawv nqaij thiab lub cev, thiab ua rau daim tawv nqaij tsim ntau yam khoom siv, thiaj li ua lub luag haujlwm ntawm kev noj qab haus huv. saib xyuas. Ultraviolet hluav taws xob yog siv los tswj kev ua haujlwm ntawm cov hlab ntsha siab, txhim kho kev pw tsaug zog thiab txo cov ntshav siab. Kev raug ultraviolet hluav taws xob tsis tu ncua tuaj yeem ntxiv dag zog rau phagocytosis ntawm cov qe ntshav dawb thiab txhim kho tib neeg lub cev tiv thaiv kab mob.
(3) Decompose organic teeb meem
Ntxiv (lossis txheej) me me ntawm nano titanium dioxide hmoov rau ntawm qhov chaw ntawm cov khoom siv hauv tsev lossis cov khoom siv hauv tsev tuaj yeem adsorb VOC (xws li formaldehyde, benzene, toluene, ethanol, chloroform, thiab lwm yam), uas tuaj yeem decomposed tom qab ultraviolet irradiation. .