Air shower

Air shower
 
Air shower room (AIR SHOWER) is also called clean air shower room, clean air shower room, air shower room, blowing shower room, air shower door, dust room, blowing shower room, air shower channel, air shower room.
 
The air shower is a necessary channel to enter the clean room, which can reduce the pollution problems caused by entering and leaving the clean room.
 
The air shower is a highly versatile local purification equipment installed between the clean room and the non-clean room. When people and goods enter the clean area, they need to be blown in the air shower. The clean air blown out can remove the dust carried by people and goods, and can effectively block or reduce the dust source from entering the clean area. The front and rear doors of the air shower/cargo shower room are electronically interlocked, which can also act as an air lock to prevent unpurified air from entering the clean area.
 
 
Structural configuration of the air shower

1. Automated control, the single-person single-air shower room system adopts PLC intelligent control methods, and the LED display on the control panel can correctly display the operating status of the air shower, the interlocking status of the double doors, the air shower cycle progress and the delayed door opening state. It is equipped with a photoelectric sensor and a one-way air shower room. It enters from a non-clean area. After the door is closed, the infrared sensor detects people and blows it.
2. Single-person single-blowing shower room mainboard soft key touch time relay, LED display and setting the blowing time, the range is adjustable from 10-99s, and the blowing time can be adjusted according to the difference of the outside environment of the wind shower room;
3. Modular structure, single-person single-blowing shower cabinet adopts modular design scheme;
4. High performance, high sealing, imported electronic components, stable and reliable operation performance, advanced noise reduction and mute device system and EVA sealing material, high sealing performance
 
 
The development trend of air shower
The intelligent voice air shower room is equipped with a voice prompt system. When blowing, the automatic voice system prompts people to complete the entire blowing and dust removal process in an orderly manner to achieve an effective purification effect. The clean air flow filtered by the high-efficiency filter can be rotated The nozzle sprays onto the body from all directions to effectively and quickly remove dust particles. The removed dust particles are filtered by the primary and high-efficiency filters and recirculated to the air shower area.
 
Intelligent voice features
Fully automatic control, electronic interlocking, double doors are locked when blowing, and infrared induction automatic blowing. Stainless steel semi-glass door automatic door closer, transparent window, inner low plate is made of stainless steel; software test controller, LED display and setting of the blowing time, adjustable from 0 to 99 seconds, with a round involute air duct inside, High wind speed, low noise.
1. Humanized control panel design, clear indicator light, and clear air shower process instructions. Soft key touch time relay;
2. High cleanliness and high wind speed: Adopt AAF primary and high efficiency filter two-stage filtration system, no partition and low resistance high efficiency filter, filtration efficiency: 99.99%, to ensure the purification level. Equipped with all-stainless steel multi-angle adjustable nozzles, double-volute outer-rotor high-volume low-noise fan, the wind speed of the nozzle outlet is up to 25m/s, and the wind speed of blowing on the person is above 18m/s.
3. Modular structure, the air shower box adopts a modular design scheme, which can be assembled into various lengths of air shower size according to actual needs. An air shower is composed of one or more air shower units. For large-volume air shower equipment, it can be divided into multiple modules, making production, transportation, and installation particularly convenient and fast;
4. High performance and high sealing: using imported electronic components, stable and reliable operation performance, advanced noise reduction and mute device system and EVA sealing material, high sealing performance.
 
 
Acceptance method of air shower room
1 General requirements
1.1 Test environment
The performance test should be carried out in a laboratory that meets the following environmental requirements:
a) Temperature: 5℃~35℃;
b) Relative humidity: 35%~85%;
1.2 Power supply
1.2.1 Power supply voltage deviation: ±10% of the rated voltage;
1.2.2 Power frequency deviation: ±2Hz (based on rated frequency).
2 Test equipment (air shower circuit board)
2.1 The test equipment should be sent to a qualified measurement and testing organization for verification on a regular basis. The test equipment can be put into use only after it has been verified and calibrated, and used within the specified validity period.
2.2 The test requires the following instruments:
a) Particle counter (the particle size resolution starts from 0.3μm);
b) Hot bulb anemometer, measurement error ≤±3% of full scale;
c) Sound level meter, the measuring range should be 40 dB(A)~100dB(A);
d) Illuminance meter, measuring range is 0 lx ~1000lx;
e) Leakage current measuring instrument;
f) Grounding resistance tester;
g) Withstand voltage tester, the output is 50Hz, the basic sine wave voltage is 1500V, and the duration can be set in the range of 1s to 60s.
3 Appearance requirements
The appearance requires visual inspection.
 
 
Use of air shower
The ultraviolet germicidal lamp is actually a low-pressure mercury lamp. The low-pressure mercury lamp emits ultraviolet light by being excited by lower mercury vapor pressure. There are two main emission spectral lines: one is 253.7nm wavelength; the other is 185nm wavelength, both of which are invisible to the naked eye. Because ultraviolet rays can kill cells, be careful not to directly irradiate human skin, especially eyes, when sterilizing ultraviolet rays. Do not look directly at the lamp when the ultraviolet germicidal lamp is on. Since short-wave ultraviolet rays do not pass through ordinary glass, it can be avoided by wearing glasses Eye injuries. Infrared automatic induction air shower room means that after the infrared sensor is cut off from the light sensor at the other end, the entire intelligent circuit board system detects people standing in the induction area and automatically starts all the devices, so as to achieve automatic showering. Therefore, it is not advisable to turn on the UV germicidal lamp for a long time when using the UV germicidal lamp in the air shower. Set the jog switch to turn on the UV germicidal lamp to protect the operator and reduce human damage.
 

 
Operating procedures
The use of air shower:
1. After opening the stainless steel air shower door and entering the air shower room, the air shower door will automatically close the outer door immediately, infrared (sound control / human heat) induction, the air shower will automatically start, blowing for 15 seconds (factory set). Note: The two stainless steel doors of the air shower room cannot be opened at the same time when the shower is blown. Forcible opening will damage the electronic lock. The two doors of the air shower room are controlled by electronic interlocking.
2. After blowing in the air shower room, open the door and enter the clean room.
 
 
Install
When the air shower room is installed at the entrance of the clean room, there should be no gap between it and the wall panel of the clean room. If there is air leakage, please trim it with a caulking agent, and pay attention to the level of the equipment installation, otherwise it will affect the door opening And durability. The equipment is divided into base type and non-base type. The base type can be adjusted directly after leveling, and then filled and decorated with silica gel. The baseless type needs to be fixed with expansion screws and then filled with silica gel for modification. For the wiring of the power supply, please connect it to the R, S, T, and E terminals of the terminal block in the junction box above the equipment according to the voltage shown in the specification.
 
 
Maintenance party

1. Pre-filter (PRE-FILTER): The pre-filter is under the equipment. Please remove the circulating air return air vent to easily pull out the pre-filter. The blockage of the pre-filter varies according to the frequency of use and cleanliness. Please observe the blockage time at the beginning of use, and then clean it with compressed air, water washing, vacuum cleaning, etc. on a regular basis. It is necessary to clean 2-3 times a month according to normal usage.
2. Main filter (MAIN FILTER) This filter is located after AIR NOZZLE. The renewal period can be based on the wind speed value detected by the anemometer (the wind value is halved) or the pressure difference measured by the pressure difference meter (the pressure difference value is doubled) to determine the replacement and No, the inspection cycle is about two to four times a year.
3. Because the return air part of the equipment is located under the machine, there will be large dirt on the bottom plate that will accumulate in the corners, so please use a vacuum cleaner to clean it more than once a week. Please confirm whether the rotation direction of the blower is correct. If you find that the fan rotates in the opposite direction (the wind speed is obviously insufficient), please swap any 2-phase power cords in the three-phase power supply to make sure it rotates in the positive direction.
 
 
Control maintenance
The control of the number of dust particles in the clean room, and the environmental control and daily maintenance of the air shower room in the clean room are very important. The air purification system plays a very key role. When the air cleanliness required for injection production is level 100, vertical and horizontal unidirectional flow patterns are used, and the airflow velocity is greater than 0.25 m/s and 0.35 m/s respectively; when the air cleanliness requirements are 10,000 and 100,000, use Non-unidirectional flow, the air exchange frequency is greater than 25 times/hour and 15 times/hour (300,000 air exchange frequency is not less than 12 times/hour), in order to take away the dust and dust generated in the production process in time, and maintain a clean room environment Cleanliness.
 
Clean rooms are divided into biological clean rooms and non-biological clean rooms. The biological clean room air purification system must be continuously operated; the air purification system should be turned on 4 hours in advance before the use of the non-biological clean room. The dust particle counter used to detect dust particles is carried out after buffering for 0.5 to 1 hour after environmental sanitation and cleaning. In order to avoid man-made pollution, there are only two persons in the clean room during static testing. The key control points should be dynamically monitored during the production process of injections. Control of microbial content. The control of the microbial content in the clean room environment still relies on good air purification system facilities, and its filtration efficiency can reach 99.9% to 99.99% to filter out bacteria and dust in the air. In the production, the temperature in the clean room is strictly controlled at 18～26℃, and the relative humidity is controlled at 45%～65% to destroy the growth conditions that are conducive to bacteria, plus the cleaning and disinfection of the disinfectant. Regarding the daily disinfection of the disinfectant, after the daily production, use 75% ethanol or 2‰ neo-germite solution to wipe the machine, desktop, doors and windows, automatic air shower, purification workbench, clean shed, FFU fan filter unit, wall, etc. 3%～5% of Lysurer wipes and disinfects the floor. After every 3 days of production, use 75% ethanol or 2‰ neocerin solution to wipe and disinfect the surfaces of all facilities, ceilings, and lighting in the clean room, and 3% to 5% of Lysurer to disinfect the ground.
 
Strictly controlling the pressure difference between the clean room and the adjacent room is also an important part of ensuring the cleanliness of the air in the production room. The pressure difference between the clean room and the clean area and the non-clean area of ​​different cleanliness should be greater than 5 Pascals, the pressure difference between the clean area and the outdoor should be greater than 10 Pascals, and the opening and closing of the supply air, return air and exhaust air flow should be connected Lock and operate in sequence, which can avoid air backflow and reduce the pollution of clean room environment by low-level dust. Before each production and after a certain production cycle, the number of dust particles in the clean room after cleaning must be tested under static conditions to evaluate and grasp the content of dust particles in the clean room.
 

The purpose of environmental control and daily maintenance of the air shower room in the clean room is to kill the bacterial propagule produced during the production process and control the microbial content in the clean room. These measures can only control the amount of bacteria and the types of bacteria in the air in the clean room. If there are more molds, you must first spray the room with 5% carbolic acid, and then fumigate with formaldehyde to achieve sterile effect, and only in this way can it be killed. Bacteria, spores of miscellaneous bacteria. At the end of each production cycle, before the next cycle of production, the clean room with aseptic requirements shall be disinfected with disinfectant. After the number of dust particles in the clean room meets the requirements, the clean room is fumigated with formaldehyde gas. The results of the long-term test See, this environmental sterilization method works well.
 
Formaldehyde gas sterilization technology. Formaldehyde fumigation not only has a good sterilization effect on molds that are not easy to kill, but also has a better killing effect on bacterial spores in the environment. Attention should be paid to the operation of formaldehyde fumigation: firstly, ensure that the room temperature is above 35℃ and the relative humidity is above 60%; secondly, ensure that the amount of formaldehyde reaches the ratio of 10 g/m3 of room volume; in addition, the room disinfection time is not less than 12 hours; it is especially worthwhile It is reminded that the same proportion of ammonia should be used for neutralization before the formaldehyde replacement, which will minimize the harm to the human body and the pollution to the environment. In order to prevent bacteria from developing resistance to formaldehyde, it is better to use ozone for alternation.
Reduce the impact of people on the sterile environment.
 
People are the biggest source of pollution in a sterile environment. Therefore, the number of people working in the clean area and the operating room, the range of operations, and the style, texture, and wear of work clothes have a significant impact on the content of particles and bacteria.
 

 
Blowing system
Generally speaking, the principle of the infrared automatic induction blowing shower system in the air shower room can be divided into two categories. The first category, in simple terms, uses the photoelectric effect of semiconductor materials. For example, when infrared radiation enters a semiconductor PN junction, it will cause The excitation of the current carriers in the semiconductor produces the migration of electrons and holes under the action of the built-in electric field of the PN junction. If a wire is added to both ends of the PN junction and a load is applied, the voltage change can be measured at both ends of the load. This achieves the purpose of infrared induction.
 
This type is called photon infrared detection (induction). It is known that infrared radiation must be accompanied by thermal effects. When some objects absorb infrared radiation, it will cause the temperature of the object to change.
The principle of the second type of infrared sensing is designed by using infrared radiation to cause the temperature of the object to change, which is called thermal infrared detection.
 
The entire intelligent circuit board system of the automatic induction system detects people standing in the induction zone and automatically starts all the devices, so as to achieve automatic blowing. The automatic door induction system of the non-automatic door air shower room referred to above.
 
Air shower room infrared automatic induction blowing system work flow: Generally, when people enter the air shower room to blow shower area, the system will automatically sense the blowing shower. After the infrared automatic induction blowing, the fan introduces air from the outside through the primary filter and then is pressed into the static pressure box of the air shower room by the centrifugal fan, and then filtered by the high efficiency filter, the clean air is sprayed from the nozzle of the air shower room at high speed to achieve Purpose of air shower room purification.
 
 
Troubleshooting
1. When the air shower room is used for a period of time, if the wind speed is very low, you should immediately check whether the filter in the air shower room can accumulate too much dust, if it is a new one, replace the filter. Usually it is necessary to exchange it every 1-6 months, and the high-efficiency filter is usually exchanged every 6-12 months.
2. If the air shower room cannot automatically sense the blowing, check the light sensor system at the lower right corner of the air shower room to see if the light sensor equipment is correct.
If the emergency stop button is red, it means that the air shower room will not blow, and you only need to press the emergency stop button from the beginning to work normally.
3. When the air shower is not in operation, first check whether the emergency switch of the outer box of a disadvantaged shower door can be blocked.
4. The fan in the air shower room is reversed. Perhaps the wind speed in the air shower room is very low. It is necessary to check whether the 380V three-phase four-wire line can be reversed. If the line source of the air shower is reversely connected, the lighter one will cause the fan in the air shower room to not operate or the wind speed of the reverse air shower room decreases, and the heavy one will burn the circuit board of the entire air shower room.
 
 
Nine maintenance
1. Use instruments to measure the technical indicators of the equipment on a regular basis. If the technical parameters do not meet the requirements, they should be dealt with in a timely manner.
2. According to actual usage, regularly remove the filter material in the primary air filter for cleaning.
3. When the wind speed is found to be small, first check whether the surface of the primary air filter is black. If it is black, it means that the pre-filter contains more dust and the resistance increases, that is, the non-woven in the primary air filter should be removed The cloth is cleaned or replaced.
4. When the non-woven fabric is exchanged or cleaned, the wind speed cannot be increased, which means that the high efficiency air filter has been blocked, causing increased resistance, and the high efficiency air filter should be replaced.
5. When replacing the high-efficiency filter, you must remove the spray ball plate, take out the high-efficiency filter, and replace the new high-efficiency air filter according to the specifications and models of the original high-efficiency filter. When installing, confirm the arrow mark on the high-efficiency filter, and the arrow should point to the direction of the airflow. And to ensure a good seal to prevent leakage.
6. After the high-efficiency filter is replaced, it is necessary to confirm that there is no leakage in the frame, and use a dust particle counter to detect it, and it can work normally after reaching the technical indicators.
7. Regularly check and repair the electrical circuit. If there is a fault, you can refer to the electrical schematic diagram for repair.
8. Enclose the door regularly to align the electronic lock with its lock hole to prevent the lock pin from jamming.
9. The use temperature should not exceed 50℃, and the use of open flames is strictly prohibited.
 
 
Common malfunctions
1. Power switch, usually there are four places in the air shower room to cut off the power:
1. The power switch of the outdoor cabinet of the air shower;
2. The control panel of the air shower chamber;
4. On the outer boxes on both sides of the air shower room (the power switch here can prevent the power supply from being cut off in an emergency, and effectively improve our personal safety). When the power indicator does not work, do not prevent to re-check the power supply of the above four air shower rooms.
 
2. When the fan of the air shower room is not working, check whether the emergency switch of the air shower outdoor cabinet is cut off at the first time.
 
3. If the fan in the air shower room is reversed or the wind speed in the air shower room is very small, please be sure to check whether the 380V three-phase four-wire line is reversely connected. Generally, a dedicated electrician will connect the wires during factory installation; if the air shower room is reversely connected The light source will cause the fan in the air shower room to not work or the wind speed of the reverse air shower room will decrease, and the severe one will burn the circuit board of the entire air shower room; we should not change the wiring lightly.
 
4. The air shower room does not blow. In addition to the above three points, it is necessary to check whether the emergency stop button inside the air shower room box is pressed. If the emergency stop button is in warp color, the air shower room will not blow; To press the emergency stop button again, it can work normally.
 
5. When the air shower cannot automatically sense the shower, check the light sensor system in the lower right corner of the air shower room to see if the light sensor device is installed correctly. If the light sensor is opposite and the light sensor is normal, the air shower can be automatically sensed. .
 
6. When the wind speed of the air shower room is very low for a period of time, please check whether the initial and high efficiency filters of the air shower room have too much dust. If so, please replace the filter. (The primary filter in the air shower room is generally replaced within 1-6 months, and the high-efficiency filter in the air shower room is generally replaced within 6-12 months)
 
 
Application

The air shower room is used in various dust-free workshops, non-dust-free workshops, and step cleanliness workshops such as microelectronics, optoelectronics, semiconductors, medicine, food, chemicals, aviation, automobiles, printing, laboratories, etc. In the process of entering a high-cleanliness room, remove dust particles larger than 0.3 microns from various parts of the person to avoid pollution after entering the clean room. At the same time, it also plays a role of airflow buffering, because in the process of opening the door, there is a flow of air, the air shower room well stops the air flow inside the air shower room, which avoids air pollution caused by air flow.