Air disinfection is an important measure to prevent hospital infections. The use of an air disinfector can effectively clean the air in the operating room, purify the operating environment, reduce surgical infections, and increase the success rate of surgery. It is suitable for air disinfection in operating rooms, treatment rooms, wards and other spaces.
working principle:
There are many types of air disinfection machines, and there are many principles. Some use ozone technology, some use ultraviolet lamps, some use filters, some use photocatalysis, and so on.
1. Primary filtration, medium and high efficiency filtration, electrostatic adsorption filtration: effectively remove particles and dust in the air.
2. Activated carbon net: deodorizing function.
3. Photocatalyst network
Antibacterial mesh assists in disinfection. Generally, nano-level photocatalyst materials (mainly titanium dioxide) are used in conjunction with the irradiation of a violet lamp to produce positively charged "holes" and negatively charged negative oxygen ions on the surface of titanium dioxide, "holes" and water in the air The steam combines to produce strong alkaline "hydroxide radicals", which decompose formaldehyde and benzene in the air, turning them into harmless water and carbon dioxide. Negative oxygen ions combine with oxygen in the air to form "active oxygen", which can decompose bacterial cell membranes and oxidize virus proteins to achieve the purpose of sterilization, detoxification and decomposing harmful gases.
4. Ultraviolet
To achieve the inactivation of bacteria in the air, the closer the ultraviolet lamp tube is to the object to be disinfected, the more bacteria will be killed and faster. In the range of ultraviolet radiation, the mortality rate of bacteria can be guaranteed to be 100%, and no bacteria can escape.
The principle of sterilization is to use ultraviolet rays to irradiate bacteria, viruses and other microorganisms to destroy the structure of DNA (deoxyribonucleic acid) in the body, causing it to immediately die or lose its ability to reproduce. Quartz UV lamps have advantages, so how to identify true and false. Different wavelengths of ultraviolet light have different sterilization capabilities. Only short-wave ultraviolet (200-300nm) can kill bacteria. Among them, the sterilization ability is the strongest in the range of 250-270nm. The cost and performance of ultraviolet lamps made of different materials are different. Really high-intensity, long-life UV lamps must be made of quartz glass. This type of lamp is also called quartz germicidal lamp. It is divided into two types: high-ozone type and low-ozone type. High-ozone type is generally used in disinfection cabinets. Quartz ultraviolet lamp has a remarkable feature compared with other ultraviolet lamps. In addition, it produces high ultraviolet intensity, which is more than 1.5 times that of high-boron lamps, and the ultraviolet radiation intensity has a long life. The most reliable way to distinguish is to use the 254 nm probe of an ultraviolet irradiance meter. For the same power, the quartz ultraviolet lamp has the highest ultraviolet intensity at 254 nm. The second is the high boron glass ultraviolet lamp. The ultraviolet light intensity of the high boron glass lamp is easily attenuated. After hundreds of hours of lighting, its ultraviolet light intensity drops sharply, down to 50%-70% of the initial. In the user's hand, although the lamp is still on, it may no longer work. The light attenuation of quartz glass is much smaller than that of high-boron lamps. Lamp tubes coated with phosphors, no matter what kind of glass they are made of, it is impossible to emit short-wave ultraviolet rays, let alone ozone, because the spectral lines emitted by phosphor conversion have a shortest wavelength of around 300 nm, which is in the disinfection cabinet. What can often be seen is the mosquito killer lamp, which can only produce 365nm spectrum and a part of blue light. It has no disinfection effect at all except for attracting mosquitoes [2].
5. Negative ion generator
It can efficiently remove dust, sterilize, and purify the air. At the same time, it can activate oxygen molecules in the air to form oxygen-carrying negative ions. Negative oxygen ions combine with oxygen in the air to form "active oxygen, which can decompose bacterial cell membranes and oxidize virus proteins, achieving the purpose of sterilization, detoxification, and decomposition of harmful gases.
6. Plasma generator
Low-temperature plasma is usually produced by gas discharge. In addition to ground-state neutral particles, it is rich in electrons, ions, free radicals and excited molecules (atoms). It has extraordinary molecular activation ability and can effectively kill microorganisms and bacteria. The plasma is electrically neutral as a whole. However, there are a large number of positive and negative charges inside. Due to the Coulomb and polarization forces of the charges, they collectively exhibit a huge electric field, which is the most significant feature of the existence of plasma.
The bipolar plasma electrostatic field is used to decompose and break the negatively charged bacteria, polarize and adsorb the dust, and combine components such as drug-impregnated activated carbon, electrostatic net, photocatalyst catalytic device and other components for secondary sterilization and filtration. The clean air after treatment is large and fast Circulating flow keeps the controlled environment at the standard of "sterile clean room".
Plasma air disinfection and purification technology is a brand-new technology integrating physics, chemistry, biology and environmental science. Plasma is also known as the fourth state of matter. Low-temperature plasma is usually produced by gas discharge. In addition to ground-state neutral particles, it is rich in electrons, ions, free radicals and excited molecules (atoms). It has extraordinary molecular activation ability and can effectively kill microorganisms and bacteria. The plasma is electrically neutral as a whole. However, there are a large number of positive and negative charges inside. Due to the Coulomb and polarization forces of the charges, they collectively exhibit a huge electric field, which is the most significant feature of the existence of plasma.
Under the action of an external high-voltage electric field, the escaping electrons and free electrons are accelerated to obtain high energy. In the movement of high-energy electrons, it collides with gas molecules and atoms inelastically, and its kinetic energy is converted into the internal energy of ground-state molecules (atoms), which triggers super-excitation, dissociation and ionization processes to form plasma. On the one hand, the huge internal electric field acts. It causes serious breakdown and damage to the bacterial cell membrane; on the other hand, it opens the gas molecular bonds to generate some monoatomic molecules and negative oxygen ions, OH ions and free oxygen atoms and other free radicals, which have the ability of activation and strong oxidation, and the excited particles can also Radiation of ultraviolet rays, this is the mechanism of plasma disinfection. Using this principle, a high voltage is applied to the needle-shaped or wire-shaped electrode to generate a corona discharge, and a large-scale stable plasma is generated to kill bacteria, viruses, and decompose harmful organic matter.
7. Ozone generator:
The ozone produced by the ozone generator is an allotrope of oxygen. It is a light blue and unstable gas. It consists of three oxygen atoms and has a molecular formula of O3. It decomposes into nascent oxygen at room temperature. It is a strong oxidant. , Its oxidizing ability is second only to fluorine.
The ozone generator in the air disinfection machine is mainly made by electrolysis. Generally, large and medium-sized ozone generators have two types of oxygen source and air source, which directly electrolyze oxygen into ozone. The ozone produced by the ozone generator can instantly complete oxidation at low concentration; it has a fresh smell when it is small in amount, and it has a strong smell of bleaching powder when it is high in concentration. Ozone, organic and inorganic substances can both produce oxidized melons. Practice has proved that ozonized gas is used for water treatment, decolorization, deodorization, sterilization, algae and virus inactivation; removal of manganese, removal of sulfide, removal of phenol, removal of chlorine, removal of pesticide odor, petroleum products, and disinfection after synthetic washing; Oxidant, used in the synthesis of certain spices, refining drugs, synthesis of grease, and the manufacture of synthetic fibers; as a catalyst for quick drying of inks and coatings, combustion-supporting and wine fermentation, various fiber pulp bleaching, decolorization of full detergents, fur processing Deodorization and sterilization of parts; it plays a role in disinfection and deodorization in hospital wastewater treatment. In terms of wastewater treatment, it can remove phenol, sulfur, cyanide oil, phosphorus, aromatic hydrocarbons and metal ions such as iron and manganese.