1.
1) sources of dry air-space disinfection, tap water treatment, swimming pool water, aquaculture water, production circulating water, reclaimed water reuse, etc.
2) Oxygen-enriched sources-places with high ozone concentration demand, such as pure water, mineral water, sewage treatment, pharmaceutical and food workshops, etc.
3) Industrial oxygen sources-places with high requirements on purity and concentration, and applications with small gas volume.
2. For large-scale space disinfection applications, such as workshop disinfection in medicine, food and other industries, it is generally necessary to install special pipes to distribute the ozone to the workshop, so that some of them are connected to the air duct of the central air conditioner, but this way sometimes leads to corrosion of the air duct metal parts and ozone consumption.
3. Water treatment is mainly equipped with dosing devices for dissolving ozone in water, which are generally divided into aeration type (direct aeration or oxidation tower), venturi jet type, vortex negative pressure suction type or HICHINE pump mixing type. The water solubility efficiency is improved in turn, and the pump efficiency can reach more than 95%.
4.
1) aeration type: tap water, aquaculture water, production circulating water, domestic sewage, industrial wastewater, etc.
2) Venturi jet: secondary water supply, purified water, mineral water, aquaculture water cooling, swimming pool water, etc.
3) Negative suction type: small water body application.
4) Gas-liquid mixed pump type: small water body application or ozone disinfection water application.
Supplement:
Household air disinfection: transplant the ozone generator into the air conditioner, and install an ozone catalytic decomposition adsorption device at the air outlet, which can not only cool and heat, but also disinfect and purify the air together with indoor circulating air. The decomposed oxygen and negative ions can keep the indoor air fresh. In addition, the ozone generator used for air disinfection can also be used in hotels, restaurants, shopping malls, theaters and other public places.
Sterilization inside the refrigerator: Experiments show that there are a lot of low-temperature bacteria in the refrigerator, as well as Listeria, Yersinia and Staphylococcus aureus, which make people seriously ill. Through random sampling, it is found that there are 7850 bacteria per square centimeter in ordinary refrigerators, which is higher than the concentration of bacteria in toilet seats. In some refrigerators where leftovers are often placed, there are 129000 bacteria per square centimeter. Putting the ozone generator into the refrigerator can kill all kinds of low-temperature bacteria. The ozone concentration required to kill bacteria on the surface of objects and refrigerator partitions is dozens of times that of bacteria in the air. Wokesmart refrigerator can handle different bacterial strains separately.
GMP verification of air disinfection in pharmaceutical industry: central air conditioning purification system, ozone sterilization cabinet and other production spaces without central air conditioning system are sterilized in clean production areas. A considerable number of pharmaceutical enterprises in China use ozone as the main means of disinfection and air sterilization, such as Shenyang Jishi Pharmaceutical Co., Ltd., Dalian Zhen 'ao Pharmaceutical Co., Ltd., Shanghai Qing 'an Pharmaceutical Co., Ltd., Jilin Aodong Pharmaceutical Group Yanji Co., Ltd., Fujian Xing 'an Pharmaceutical Co., Ltd., etc. As the main means of air disinfection, ozone has made important contributions to GMP verification of these enterprises.
Hospital air disinfection: hospital wards, outpatient operating rooms, treatment rooms, etc. In Japan, 28 hospitals use ozone as air disinfection, including Sapporo Self-Defense Force Hospital and Nagoya Health University. As many as 53 units and hospitals use ozone technology to treat food and health care. There are 5/kloc-0 hospitals using ozone in Taiwan Province province, and there are Beijing Hospital and Beijing You 'an Hospital in China.
Military air disinfection: Western countries have developed military ozone air disinfection products, such as installing ozone generating devices in the cabins of military vehicles and ships such as space capsules, submarines and tanks to purify the space environment and disinfect and sterilize. This product is powered by batteries or photovoltaic cells. The main ways of ozone generation are corona method, electrolysis method, ultraviolet method, nuclear radiation method, plasma method and so on. The ozone generation technologies that have been put into use in food, hospitals and pharmaceutical enterprises mainly include corona discharge and low-voltage electrolysis.
Corona high voltage discharge method
The principle of ozone generation by corona discharge is that a dielectric (usually made of hard glass or ceramic or stainless steel) is placed in parallel between two parallel high-voltage electrodes, and a certain discharge gap is maintained. When high voltage alternating current is applied between two electrodes, a uniform blue-purple corona discharge is formed in the discharge gap. Air or oxygen passes through the discharge gap, and oxygen molecules are excited by electrons to gain energy, which elastically collide with each other and polymerize into ozone molecules.
Low pressure electrolysis
The principle of ozone generation by low-voltage electrolysis is to decompose deionized water by connecting the anode and cathode of solid membrane electrode with low-voltage direct current. Water is separated into hydrogen and oxygen molecules in the form of proton exchange at the special anode solution interface, and hydrogen is directly discharged from the cathode solution interface. Excited by electrons generated by high-density current, oxygen molecules gain energy at the anode interface and polymerize into ozone. Electro-oxidation is a sampling low-pressure electrolysis method. The low-pressure electrolytic ozone generator uses pure water as raw material, solid precious metal polymer as electrolyte, and combines cation exchange mode to obtain ozone through low-pressure electrolysis without adding any auxiliary materials and additives. The generated ozone concentration is as high as 20% or more, and the generated ozone gas is accompanied by oxygen, without any secondary pollution. Ozone is most suitable for systems with stable water quality and water consumption, and the amount of ozone should be adjusted in time when it changes. In actual production, it is difficult to adjust in time.
Another problem to be considered is the content of organic matter in water. When the turbidity of water is less than 5 mg/L, it has little effect on ozone disinfection and sterilization, and the turbidity increases, which affects the disinfection effect. If the organic matter content is high, the ozone consumption will increase and the disinfection ability will decrease, because the ozone will be consumed on the organic matter first instead of killing bacteria.
Therefore, foreign pharmaceutical companies have added monitoring items of switchboard carbon (TOC) in pharmaceutical water systems. Unfortunately, after the seriously polluted water is treated by ozone, organic macromolecules will break into the nutrient source of microbial metabolism. Therefore, if the ozone concentration in the pipe network is not maintained, the sludge will increase and the water quality will deteriorate.
In many aspects, ozone and chlorine have complementary advantages as disinfectants. Ozone can quickly sterilize and inactivate viruses, and generally has a good effect on smell, taste and chromaticity. Chlorine, on the other hand, has a durable, flexible and controllable sterilization effect and can be used continuously in the pipe network system. Therefore, the combination of ozone and chlorine seems to be the most ideal method to disinfect the water system.
Advantages of ozone disinfection method
1. is superior to chemical disinfection: ozone, as an efficient, broad-spectrum gas disinfectant with no residual pollution, has special advantages over disinfectants commonly used in food industry. Compared with chemical disinfectants such as peracetic acid, potassium permanganate, formaldehyde (formalin) and sulfur dioxide, its bactericidal ability is equivalent to peracetic acid and higher than other disinfectants.
Ozone will decompose into oxygen by itself, without residual pollution, and there is no need for ventilation after disinfection. Conventional disinfection needs ventilation or chemical neutralization, which is troublesome and reduces the disinfection effect. Ozone can directly sterilize or prevent mildew and keep food fresh. It is a dry disinfection method, which is simple and easy to implement. Ozone sterilization concentration is extremely weak oxidation concentration for food, which is harmless to food.
2. Better than ultraviolet irradiation
(1) Ozone is everywhere, with no dead ends. Only when ultraviolet rays reach the surface of an object and reach a certain irradiation intensity standard can they play a bactericidal role. Generally, food workshops are relatively high, which leads to insufficient ultraviolet radiation intensity, especially for long distance and large dead angle, such as processing the lower part of the chopping board. Ozone is a gas with strong permeability, good diffusivity, uniform concentration and no dead angle.
(2) the sterilization speed is fast. Ultraviolet irradiation takes a long time to sterilize, generally more than 6 hours, while ozone with standard concentration only needs to be turned on 1 hour or more.
(3) The sterilization effect is better under high humidity. When the relative humidity of the environment reaches more than 60%, the disinfection effect drops sharply, and when the humidity reaches more than 80%, bacteria can be induced to revive. Ozone is the opposite, and the higher the humidity, the better the sterilization effect. This is because the cell membrane swells and thins under high humidity, and its tissue is easily destroyed by ozone, which is especially suitable for the high humidity environment common in food industry.
(4) It has low concentration cleaning function. Production personnel must leave the site when ultraviolet radiation is applied, and it is impossible to use low-power ultraviolet radiation for cleaning after irradiation is completed; During ozone disinfection, the production personnel must leave the site. After disinfection is completed, the amount of ozone produced can be reduced, and the air in the production workshop can be kept clean with low concentration ozone that meets the national hygiene standards.
3. Excellent deodorizing and purifying effects
With its strong oxidation performance, ozone can quickly decompose organic or inorganic substances that produce odor and other odors to achieve deodorization effect, and decompose odor root substances into harmless substances. For example, ammonia is oxidized to carbon dioxide and water.
It is mainly composed of feed gas (compressed air or oxygen) supply system, ozone generator host, ozone delivery system and ozone generator cooling system.
Concentration The ozone concentration of air source can reach 3% ~ 6% wt, and the oxygen source can reach 6% ~ 14% wt. The gas source is18 ~ 30kw h/kgo3.
The common data of oxygen source ozone is 9 ~15 kw h/kgo3.
1. The specifications of the ozone generator are divided according to the weight units produced by ozone. The unit of ozone generation is mg/h or g/h (mg/h, g/h), that is, how many weight units of ozone can be generated when the ozone generator works 1 hour.
2. The concentration unit of ozone in the air is ppm or; The unit of ozone concentration in water is ppm or mg/L. Conversion method: in air,1ppm = 2.144; In water, 1 ppm = 1 mg/liter.
When ozone reaches a certain concentration in the atmosphere, it will cause environmental pollution. According to China's regulations, when the ozone concentration exceeds 0. 16 in the living environment, it constitutes air pollution; In the workplace, ozone concentration exceeding 0.2 constitutes pollution.
1. The basic principle of ozone concentration detector comes from Ansrose company in Germany.
1. 1 detection principle
We know that there is ozone layer in the earth's atmosphere. Scientists found that the ozone layer can absorb ultraviolet rays. The results show that ozone has the maximum absorption coefficient only for ultraviolet rays with the wavelength of 253.7nm, and ultraviolet rays will be attenuated by ozone at this wavelength, which conforms to lamport-Beer law. In the United States and other countries, this method has been used as the standard ozone analysis method.
Ozone detector adopts the principle of ultraviolet absorption, uses a stable ultraviolet light source to generate ultraviolet light, and uses a light wave filter to filter out ultraviolet light with other wavelengths, allowing only light with a wavelength of 253.7nm to pass through. After passing through the sampling photoelectric sensor and ozone absorption cell, it reaches the sampling photoelectric sensor. The ozone concentration can be calculated by comparing the electrical signals of the sample photoelectric sensor and the sampling photoelectric sensor, and then by mathematical model.
Realization of 1.2 circuit principle
The basic circuit consists of six parts: power supply, ultraviolet lamp control, ultraviolet sampling detection, ultraviolet sampling detection, logarithmic amplifier Log 100, analog output and display.
2. Ozone concentration detector
Basic structure
The detector is mainly composed of low-voltage ultraviolet lamp, light wave filter, incident ultraviolet reflector, ozone absorption cell, sample photoelectric sensor, sampling photoelectric sensor, output display and circuit elements. (as shown in figure 2)
3. Main technical indicators
3. 1 Displayable unit: O3g/m3, mg/m3; parts per million
3.2 measuring range: 0 ~ 10o3g/m, 0 ~ 10o3g/m, 0 ~ 200o3g/m.
4. 1 calibration instrument calibration
The ozone detector of GM-PRO standard of Ansrose Company in Germany is adopted, and the distribution of the produced ozone detector is compared with that of 10 test points, and the error range is controlled within 1% to be qualified.
conclusion
The ozone concentration detector developed in this paper adopts ultraviolet absorption method, single light source and double light path detection, with small volume, high precision and good stability, and can work continuously. Its measuring range is wide, with the maximum measuring range of 300 o3g/m. In addition, the detector also has an analog output of 0/4-20 Ma, which can form an ozone closed-loop automatic control system with an ozone generator and a PID regulator.
References:
1. Handbook of Ozone Technology and Application, RICE, RIPG, NETZER ANN ARBIR SCIENCE, 1982.
2. Ansrose Company, Wang Wei. Handbook of ozone technology and application abroad.