Ultraviolet disinfection lamp solution development

1. The principle of ultraviolet disinfection

At present, disinfection methods can be divided into two categories, namely chemical disinfection and physical disinfection. Chemical disinfection methods include chlorine disinfection and ozone disinfection, etc.; physical disinfection methods include ultraviolet disinfection. The principle of ultraviolet disinfection is to use ultraviolet rays of appropriate wavelengths to destroy the molecular structure of DNA (deoxyribonucleic acid) or RNA (ribonucleic acid) in the cells of microorganisms, causing growth cell death and (or) regenerative cell death, to achieve sterilization Effect. After testing, the effective wavelength range of ultraviolet sterilization can be divided into four different bands: UVA (400-315nm), UVB (315-280nm), UVC (280-200nm) and vacuum ultraviolet (200-100nm). Among them, only UVA and UVB parts can reach the earth's surface through the ozone protective layer and clouds. In terms of sterilization speed, UVC is within the range of microbial absorption peaks, and can kill viruses and bacteria by destroying the DNA structure of microorganisms within 1 second, while UVA and UVB are outside the range of microbial absorption peaks, and the sterilization speed is very slow. It often takes several hours to play a bactericidal effect. In the hydraulic retention (irradiation) time of several seconds in the actual project, this part actually belongs to the invalid ultraviolet part. The penetration ability of vacuum ultraviolet light is extremely weak, and the lamp tube and casing need to use quartz with extremely high light transmittance. Generally, it is used in the semiconductor industry to degrade TOC in water, and is not used for sterilization. Therefore, the ultraviolet light disinfection mentioned in the water supply and drainage project actually refers to UVC disinfection. Ultraviolet light disinfection technology is based on modern epidemiology, medicine and photodynamics. It uses specially designed high-efficiency, high-intensity and long-life UVC band ultraviolet light to irradiate flowing water to sterilize various bacteria, viruses, parasites and algae in the water. And other pathogens are directly killed to achieve the purpose of disinfection.

Studies have shown that ultraviolet rays mainly kill microorganisms through the radiation damage of microorganisms (bacteria, viruses, spores and other pathogens) and the function of destroying nucleic acids, so as to achieve the purpose of disinfection. The effect of ultraviolet rays on nucleic acids can lead to bond and chain breaks, inter-strand crosslinks, and formation of photochemical products, etc., thereby changing the biological activity of DNA and making microorganisms unable to replicate themselves. This ultraviolet damage is also fatal damage. Ultraviolet disinfection is a physical method. It does not add any substances to the water and has no side effects. This is where it is superior to chlorination disinfection. It is usually used in combination with other substances.

Ultraviolet light is a kind of light wave invisible to the naked eye. It exists outside the ultraviolet end of the spectrum, so it is called ultraviolet light. According to different wavelength ranges, it is divided into three bands: A, B, and C. Among them, the wavelength of ultraviolet light in the C band is 240 -260nm is the most effective sterilization band.

Modern ultraviolet disinfection technology is based on modern epidemiology, optics, biology and physical chemistry, using a specially designed high-efficiency, high-intensity and long-life C-band ultraviolet light generating device to generate strong ultraviolet C light to irradiate the air or On the surface of objects, when various bacteria, viruses, parasites, algae and other pathogens in the air or solid surface are irradiated by a certain dose of ultraviolet C light, the DNA structure in the cells is destroyed, so that the DNA structure in the cells can be destroyed without using any chemical drugs. Kill bacteria, viruses, and other pathogens under certain conditions to achieve the purpose of disinfection and purification. It has the advantages of high efficiency, broad spectrum, low price, long life, easy operation, low operating cost and no secondary pollution.

Ultraviolet light is a light with a shorter wavelength than visible light. It can be divided into three types according to the wavelength: A light: short-term effects will cause redness, tanning, and photosensitivity reactions, and long-term effects will cause wrinkles, dark spots, and skin aging. B light: The short-term effect is sunburn, tanning, and sunburn, and the long-term effect will be wrinkles, dark spots, and skin cancer. C light: Because the ozone layer cannot reach the surface, it cannot be seen in the short term, but it will cause skin cancer in the long term.

We can clearly understand that it is B light that is likely to cause sunburn; that is to say, when you happily go to the beach and get red and painful, and come back with a layer of skin off, it is the short-term effect of ultraviolet B light. The "indoor ultraviolet tanning method" is to use the principle of "seeking good luck and avoiding evil" to avoid ultraviolet B light and only use ultraviolet A light, so that the effect of tanning can be achieved in a short period of time, but there is no concern about sunburn. That is, in a machine equipped with many ultraviolet A light tubes, gradually increase the exposure time to achieve the purpose of gradually darkening.

2.The advantages of ultraviolet disinfection

Ultraviolet disinfection does not require chemicals and does not produce THMs disinfection by-products. The bactericidal effect is fast and the effect is good. No odor, no noise, does not affect the taste of water. It is easy to operate, simple to manage, and low in operation and maintenance costs.

Most ultraviolet devices use traditional low-pressure ultraviolet lamp technology, and some large water plants use low-pressure high-intensity ultraviolet lamp systems and medium-pressure high-intensity ultraviolet lamp systems. Due to the generation of high-intensity ultraviolet rays, the number of lamp tubes may be reduced by more than 90%, thus Reduced footprint, saving installation and maintenance costs.

3. The scope and conditions of ultraviolet disinfection

(1) Ultraviolet rays can kill various microorganisms, including bacterial propagules, spores, mycobacteria, viruses, fungi, rickettsia and mycoplasma, etc. All surfaces, water and air contaminated by the above microorganisms can be sterilized by ultraviolet rays.

(2) Ultraviolet radiation has low energy and weak penetrating power, and can only kill directly irradiated microorganisms. Therefore, the disinfection site must be fully exposed to ultraviolet rays during disinfection.

(3) When using ultraviolet rays to disinfect rough surfaces such as paper and fabrics, the irradiation time should be extended appropriately, and both sides should be irradiated.

(4) The most suitable temperature range for ultraviolet disinfection is 20-40°C. If the temperature is too high or too low, the disinfection effect will be affected. The disinfection time can be extended appropriately. When used for air disinfection, the relative humidity of the disinfection environment should be lower than 80%. , otherwise the irradiation time should be extended appropriately.

(5) When using ultraviolet rays to kill microorganisms protected by organic matter, the irradiation dose should be increased. Suspended particles in the air can also affect the disinfection effect.

4.The use of ultraviolet disinfection lamp

The intelligent controller pre-sets the combination password, which is as simple as possible and easy for the staff to remember. At this time, if the password is not entered, the ultraviolet light will not be powered on when the switch is pressed, so as to prevent patients and family members from accidentally pressing the switch and turning it on.

When irradiating, all kinds of personnel leave the disinfection place and close the door. Enter the preset combination password, set the irradiation time, the switch is closed, the timer starts counting, the ultraviolet disinfection light is on, the screen displays the irradiation time, and the cumulative timer starts to work. When the irradiation time is up, the timing switch is closed. During the irradiation process, if the door is pushed open to enter the room, the ultraviolet switch will automatically turn off the disinfection lamp and an alarm will sound. At this time, first close the door, and then press the prompt on the LCD screen on the panel to turn on the ultraviolet lamp again (continue to disinfect according to the remaining time) or completely turn off the ultraviolet lamp to end the alarm.

(1) Disinfection method for the surface of the article: it is best to use a portable ultraviolet sterilizer for close-range mobile irradiation, or a suspended ultraviolet lamp for irradiation. Small items can be irradiated in an ultraviolet disinfection box.

Exposure dose and time Different types of microorganisms have different sensitivities to ultraviolet rays. When disinfecting with ultraviolet rays, the irradiation dose must be used to achieve the irradiation dose required to kill the target microorganisms. When killing general bacterial propagules, the irradiation dose should reach 10000uW. s/em2; when killing bacterial spores, it should reach 100000uW. s/Cm; the resistance of viruses to ultraviolet rays is between that of bacterial propagules and spores; the resistance of fungal spores is stronger than that of bacterial spores, and sometimes it needs to be irradiated to 600000uW. s/Cm2; when the target microorganisms for disinfection are unknown, the irradiation dose should not be lower than 100000uW. s/Cm2. The radiation dose is the product of the radiation intensity and the radiation time of the ultraviolet lamp used at the surface of the irradiated object. Therefore, according to the irradiation intensity of the ultraviolet light source, the required irradiation time can be calculated. For example, use an ultraviolet surface sterilizer with an irradiation intensity of 70uW/Cm2 to irradiate the surface of the object at close range; the selected irradiation dose is -100000uW. s/Cm; the time to be irradiated is: 100000uW. s/Cm2÷70uW/Cm2=24 minutes.

(2) Disinfection method for indoor air: high-intensity ultraviolet air sterilizer is the first choice for indirect irradiation method. Not only the disinfection effect is good, but also it can be used when there are people in the room. 30rain can reach the disinfection standard. Under the condition of no one in the room, the direct irradiation method can adopt the suspended or mobile direct irradiation of ultraviolet lamps. When using indoor suspended ultraviolet disinfection, the number of ultraviolet disinfection lamps installed indoors (30W ultraviolet lamps, the intensity at 1.0 meters > 70uW/cm) is not less than 1.5W per cubic meter and the irradiation time is not less than 30min.

5. Precautions for using ultraviolet disinfection lamps

(1) During use, the surface of the UV lamp should be kept clean. Generally, it should be wiped once a week with a 95% absolute alcohol cotton ball. If there is dust or oil on the surface of the lamp tube, it should be wiped at any time.

(2) When disinfecting indoor air with ultraviolet light. The room should be kept clean and dry to reduce dust and water mist, the temperature should be lower than 20°C or higher than 40°C, and the irradiation time should be extended appropriately when the relative humidity is greater than 60%.

(3) When using ultraviolet rays to disinfect the surface of articles, the irradiated surface should be directly irradiated by ultraviolet rays, and the irradiation dose should be sufficient. Do not let the ultraviolet light source irradiate people, so as not to cause injury.

6. Design and realization of ultraviolet disinfection lamp

Ultraviolet disinfection lamp is a common tool for air disinfection in many hospitals in China. It is the most convenient and economical disinfection method, and it is also an important facility for controlling hospital infection. Ultraviolet rays can kill various microorganisms, including bacterial propagules, bacterial spores, Mycobacterium tuberculosis, fungi, viruses and Rickettsia, etc., and are widely used in hospitals and other public places, especially primary hospitals. But ultraviolet rays have the adverse reaction of killing normal cells, so the human body should not be exposed to ultraviolet light directly. A survey of many hospitals found that the switch of the ultraviolet lamp is the same as that of the ordinary fluorescent lamp and adjacent to it. Patients or their family members mistakenly turn on the ultraviolet lamp and cause human injury. In addition, when nursing staff use ultraviolet lamps for disinfection, they must control the disinfection time and record the cumulative exposure time of the lamp. In response to the above situation, we have developed an intelligent controller for ultraviolet disinfection lamps, which is introduced as follows.

The design function of the intelligent controller of the ultraviolet disinfection lamp is to prevent accidental opening, alarm when entering the room and automatically shut down, set the irradiation time, record the cumulative irradiation time of the lamp, etc. The design size of the switch panel is the same as that of the national standard 86 switch, and it is powered by a single live wire, which can be refitted on an ordinary switch. There are LED lights and LCD screen on the switch panel. The appearance is shown in Figure 1 and has the following functions:

(1) Timing irradiation design. Design a timer switch, half an hour or one hour after the start of irradiation (multiple irradiation times can be set and selected), it will automatically shut down when the timing ends; it can also be turned off manually through the switch on the panel. There are LED lights and LCD screen on the switch panel to indicate the working status of the UV disinfection lamp.

(2) Automatically record the cumulative use time of the ultraviolet lamp. The UV lamp will automatically accumulate timing after it is turned on, and will stop timing when the light is turned off. The original timing data will not be lost when the power is turned off. Timing will continue on the original timing data after power on; the timing accuracy is less than 15min, and the timing range is 0~6000h (general UV The lamp service life is 4000h) and can be set to zero (replace the lamp); the cumulative usage hours (h) of the ultraviolet lamp can be displayed in real time on the LCD screen of the switch panel.

(3) Safety automatic protection function. A magnetic sheet and a magnetic sensor are installed on the door of the disinfection room to detect the opening and closing status of the door, so as to prevent the accidental entry of personnel and cause injury during the disinfection process of the ultraviolet lamp. When the door is closed, the indoor ultraviolet disinfection lamp can be turned on through the ultraviolet switch (designed to be installed outside the disinfection room). When the ultraviolet light is turned on for disinfection, if someone opens the door by mistake, the ultraviolet switch will automatically turn off the disinfection light and an alarm will sound. At this time, first close the door, and then press the prompt on the LCD screen on the panel to turn on the ultraviolet lamp again (continue to disinfect according to the remaining time) or completely turn off the ultraviolet lamp to end the alarm.

(4) Switch password anti-mis-opening function. In order to prevent non-staff personnel from accidentally turning on the disinfection lamp outdoors and causing harm to indoor patients, the switch is designed with a power-on password function. That is, after turning on the switching power supply, you need to input the preset key combination first, then you can enter the function interface and use the switching function.

7. Advantages of UV disinfection lamp controller

(1) Prevent patients and family members from turning on the UV light switch by mistake: The traditional UV disinfection switch is an ordinary switch device placed indoors, which is easily injured by patients or family members by misoperation. Ultraviolet rays are harmful to human skin and eyes, and can cause skin damage. Burns, corneal inflammation, skin cancer, etc.; ozone produced by ultraviolet rays can make people age, and its smell is unacceptable, and inhaling too much can cause poisoning. Ozone enters the blood and competes with hemoglobin for oxygen, so air disinfection can only be performed in an unmanned state.

The device switch has a power-on password function, that is, after turning on the switch power, you need to enter the preset combination key first to enter the function interface and use the switch function. Prevent patients or family members from accidentally turning on the ultraviolet disinfection lamp outdoors to cause iatrogenic and occupational injuries to indoor patients.

(2) Automatically protect the human body from ultraviolet radiation: Install a magnetic sheet and a magnetic sensor on the corresponding position of the door and the door frame to detect the opening and closing status of the door. During the disinfection process of the ultraviolet lamp, if a person enters the irradiation area by mistake, the ultraviolet switch will automatically turn off the disinfection lamp and an alarm will sound. Close the door, press the prompts on the LCD screen on the panel to turn on the ultraviolet light again (continue to disinfect according to the remaining time) or completely turn off the ultraviolet light to end the alarm.

(3) Automatic timing and time-consuming irradiation time to ensure the quality of disinfection and convenient for staff to record: the traditional ultraviolet disinfection mode is a manual switch, manual timing, from turning on the light - timing - turning off the light - recording, each lamp is registered daily Disinfection time and cumulative use time increase the workload of nurses. This completely manual and mechanical operation mode is not only cumbersome, but also the nursing staff has to take care of other tasks. After turning on the light, they often forget to count the time, causing the ultraviolet irradiation time to be too long or too short, which is random and affects the quality of disinfection. After installing the intelligent control switch, it will automatically turn off and accumulate automatically after the set irradiation time is completed. The timing range is 0~6000h (the service life of the general ultraviolet lamp is 4000h). After replacing the lamp, it can be reset and restarted. The accumulated usage hours (h) of the ultraviolet lamp can be displayed on the LCD screen of the switch panel in real time, realizing complete automation. Just record the time to install or replace the UV lamp to design the timing switch.

Summarize

To sum up, the intelligent controller of ultraviolet disinfection lamp in this study can improve the safety of ultraviolet lamp disinfection, reduce the workload of people, and provide a safe, effective and convenient way of disinfection work.

The above are the details of the ultraviolet disinfection lamp solution introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. for you. If you have requirements for the development and design of UV sterilizers, you can rest assured to entrust them to us. We have rich experience in customized development of electronic products, and can evaluate the development cycle and IC price as soon as possible, and can also calculate PCBA quotations. We are agents of many domestic and foreign chips: Songhan, Yingguang, Jieli, Ankai, Quanzhi, realtek, including MCU, voice IC, Bluetooth IC and modules, and wifi modules. Our development capabilities cover software and hardware design such as PCB design, microcontroller development, Bluetooth technology development, software customization development, APP customization development, WeChat public account development, etc. It can also undertake the research and development of smart electronic products, home appliance solution design, beauty instrument development, Internet of Things application development, smart home solution design, TWS headset development, Bluetooth headset speaker development, children's toy solution development, and electronic education product development.