primary air filter

    With the continuous development of science and technology, the air quality of our life is getting worse and worse, making modern industrial production and scientific experiment activities of indoor air cleanliness is getting higher and higher. In particular, the medical industry requires miniaturization, refinement, high purity, high quality and high reliability of the indoor environment, which has high requirements for the performance of air filters.     At present, the main way to achieve this requirement is to widely use air filters in clean air conditioning systems.     The performance of various types of air filters is directly related to the grade of clean operating room. So, what are the types of air filters? What about its performance and adaptability?  Classification of air filters in clean operating rooms      Removing dust from the air relies on air filters. Filter is the core equipment in the process of air purification. The purification system is usually equipped with three stage air filtration. The first stage is at the fresh and return air outlets, the second stage is at the positive pressure section of the system, and the third stage is at the supply air end.     There are many kinds of filter, according to our national standard GB50073-2013 "clean factory design specification", the air filter is divided into four categories according to the following indicators:   Categories Filter object Initial resistance Primary air filter Particle size ≥5μm <30(Pa) Medium effect air filter Particle size 1um~5um <90(Pa) HEPA filter Particle size 0.3μm <150(Pa) ULPA filter Particle size 0.12um <220(Pa)    First, the primary air filter      Primary filter is the first level filter in air conditioning and purification system. It can also be used alone, as an air intake filter for ordinary air conditioning systems. All ventilation, air conditioning and purification systems with medium and high efficiency filters should be installed with primary filters.       The primary filter is mainly used to filter dust with particle size of more than 5um and various foreign bodies. It is suitable for the primary filtration treatment of simple air conditioning purification system and ventilation system and the occasions with high dust concentration.       Paper frame pleated filter, filter media is made of non-woven cotton and synthetic fiber by special blend, has the advantages of high dust capacity, low initial pressure loss, large air volume. The composite metal mesh provides the largest filter area for the air flow, and its filter area is 5 times that of the general plane filter. Humidity resistance up to 99%; Temperature resistance 80℃.     Mainly filter dust particles ≥5μm, used in commercial and industrial ventilation system, air conditioning system pre- filtration.  Second, medium effect air filter      In the air conditioning system, the medium effect filter is commonly used in the back of the primary effect air filter to improve purification efficiency, and in front of the high efficiency filter to extend the service life of the high efficiency filter.     The filter object of medium-effect filter is 1μm~5μm dust. The filter materials of medium effect filter mainly include polyester non-woven fabric, polypropylene non-woven fabric, medium cell foam plastic, fine cell foam plastic and medium effect glass fiber filter paper. The outer frame adopts special aluminum profile and galvanized steel frame.       Medium effect filter has the characteristics of strong tension, small resistance, large air volume and large filter area. It is suitable for intermediate filtration of air conditioning and air conditioning purification and occasions with high dust concentration. Medium filter is the most used bag structure, cleaning or replacement cycle is long.       Bag medium effect filter is suitable for intermediate filtration of air conditioning system, located in front of high efficiency filter, mainly used to filter 1-5μm dust particles, in order to protect the system filter and the system itself. It has the advantages of small resistance and large air volume. The optional styles are bag deep, frame type, combined type, etc.    Product features:  1. The filter material is made of high performance non-woven fabric with heat melting process, to avoid the discomfort of old glass fiber materials may cause to the human body; 2. The filter material contains electrostatic fiber, which has a particularly good filtering effect on sub-micron dust, with high dust capture rate, high air permeability, high dust load and high service life; 3. Filter material density increased step by step to increase the amount of dust, improve the service life of the product 4. Low initial resistance, high efficiency; 5. The appearance color uses uniform identification, easy to identify.    Third, HEPA filter      High efficiency air filter is the last stage filter in the purification system. The filter object is mainly 0.3μm~1μm dust.       For particles greater than or equal to 0.3um, the filtration efficiency is greater than or equal to 99.9%. Specifically can be divided into: V-bank filter, separator filter, mini-pleated filter.     V-bank filter, using acrylic filter paper and glass fiber filter paper as filter material, hot melt glue and silk wire as separator, outer frame plastic and plastic frame glued together. It has a large filtration area, low resistance, rated air volume and other characteristics, the general filtration efficiency of 99.97%~99.99%.       Mini-pleat HEPA filter, using thin glass fiber as filter material, hot melt adhesive as separator, metal protective mesh and filter material frame configuration, with high filtration efficiency. HEPA filter efficiency is 99.995% (0.3μm particles), ULPA filter efficiency is 99.9995% (0.1μm~0.2μm particles). Suitable for Class100-Class1000 class clean room and clean room terminal filtration device with high cleanliness rate requirement.    Fourth, electrostatic air filter      Electrostatic air filter can effectively collect dust of different particle sizes suspended in the air. In particular, 0.1μm~0.01μm particles that are difficult to be removed by ordinary air filtration can be removed by electrostatic filters.       Electrostatic filters also have the function of sterilization. Experiments show that the bacterial cysts are negatively charged. When entering the electrostatic filter's high voltage electric field, they are first polarized and positively charged. Then they enter the dust collection area and are absorbed by the high voltage electric field, and the bacterial cysts are neutralized and decomposed, thus achieving the effect of sterilization.       In order to ensure the good effect of surgical cleanliness, professional businesses should be consulted in the design of clean operating rooms. Understanding the performance of various air filters, reasonable optimization combination, in order to ensure the purification efficiency under the premise of achieving a reasonable cost performance.       And before installation, all kinds of filters are scanned for leak detection. After installation, leakage detection is carried out on the connection and compaction sealing parts to ensure the absolute reliability of the seal. Check the primary, medium and high filters regularly during use to ensure the normal operation of the filter system.

High-efficiency air outlets are ideal terminal filtration devices, widely used in medicine, health, electronics, chemicals and other industries. In order to verify whether the clean room can meet the cleanliness requirements, it is necessary to test the clean room and high-efficiency air outlets, so its detection is very important.    How to measure the air volume of high-efficiency air outlets:  1. You can use the air volume hood to directly aim at the nozzle for one-time measurement, direct measurement. Since your nozzle has many small holes (to make the air volume uniform) and there is a grille, then your anemometer can be kept 3-5 cm away from the nozzle. If you have a thermal anemometer, try to face the gap instead of the grille, and measure the average value by the grid method. The same cross-section can be measured. 2. You can measure at multiple points at a distance of 2 times the width of the diffuser from the air outlet. The measuring points should be like a grid and then the wind speed is averaged. The sizes of these vents are similar. Use tinplate or even plastic board to make a barrel that is slightly larger than the cross-section of the air outlet. When measuring, cover the barrel on the air outlet and use the anemometer to measure the nozzle of the barrel at multiple points and then calculate the average value. 3. Through the clean air conditioning circulation fan, through the high-efficiency air filter, medium-efficiency filter, and primary air filter, clean air can be obtained. The cleanliness is different and the wind flow direction is different. Of course, it is also necessary to supplement some fresh air through the fresh air outlet, otherwise people will feel stuffy inside.    Air volume measurement of high-efficiency air outlet:  1. The detection method of high-efficiency air outlet uses active sampling and passive sampling. Active sampling uses filtering method and impact method. Filtration method allows a certain amount of air to pass through an analytical filter. 2. The impact method can use Anderson sampler, Lute centrifugal sampler, and slit sampler. Passive sampling uses the landing method. Use the principle of diffusion of the open agar plate of suspended particles. 3. Of course, with the development of science and technology today, some more sophisticated detection instruments can also be used to quickly detect it.

The main materials of clean booth directly affect the cleanliness and effect of clean booth. Whether the maintenance is proper directly affects the service life of clean booth.    What materials are used in clean booth:  1. There are generally three types of frame materials for clean booth: stainless steel square tubes, iron square tubes, and aluminum profiles. 2. There are generally three types of materials for the top of clean booth: stainless steel plates, cold-rolled steel plates sprayed with plastic, anti-static mesh curtains, and organic glass. 3. For the clean air supply part, FFU laminar flow hoods (FFU fan filter units) are generally selected. 4. The enclosure materials of clean sheds generally include: anti-static curtains, (anti-static) organic glass. The functional definition of the design concept of clean booth has mentioned that "controlling the main production process in a smaller environment is also a choice for clean booth design." In fact, this is the application concept of clean booth, with low investment and control of the main process. Since the control point is higher, the cleanliness level of the clean work booth is generally designed to be very high, generally ISO level 5 and level 4, and a few use level 6.     Clean booth is an air purification equipment for local high clean environment. Clean booth is mainly composed of box, fan, primary air filter, damping layer, lamps, etc., and the outer shell is sprayed. Clean booth can be hung or supported on the ground, with compact structure and convenient use. It can be used alone or connected in multiples to form a strip-shaped clean area.   Clean booth is generally referred to as clean booth, dust-free room, etc. Generally, film enclosure is used, so it is more appropriate to call it clean booth. It is also most appropriate to understand it as clean booth if it is not polluted.