German
French
Italian
Portuguese
Japanese
Korrean
Russian
The core difference between a DOP laminar flow pass box and a clean pass box
The core difference between a DOP laminar flow pass box and a clean pass box(1) The principle of purification is very differentThe purification principle of the DOP laminar Flow pass box is like "special training" for the air. It pumps the air through an internal fan and forces it through an H14 class HEPA filter. These HEPA filters are like a strict "level", capable of intercepting small dust particles ≥0.3μm in the air, with a filtration efficiency of more than 99.995%. After such a strict filtration of clean air, it will be in the form of laminar flow, that is, like a neatly arranged team, uniform and stable flow from the top to the bottom, in the pass box to form a one-way, almost no turbulence in the clean air channel. In this way, both the transferred items and the internal air can maintain a high degree of cleanliness under the "protection" of this pure air flow. The self-cleaning transfer window in the clean pass box also has its own set of "logic" for its purification principle. It first uses a coarse filter to preliminarily filter the incoming air and intercepts some large dust particles, hair, and other impurities. The initially filtered air is then pressed into a static chamber by a low-noise centrifugal fan, where it is buffered and stabilized. The air then passes through a HEPA filter for a second fine filtration to remove even smaller dust particles. After these two stages of filtration, the clean air will pass through the work area at a uniform wind speed, forming a relatively clean environment. At the same time, the ventilation gap between the inner bladder of the transfer window and the outer frame enables the air to circulate inside and be continuously purified, thus maintaining the cleanliness of the work area. (2) Competition in cleanliness levels In terms of cleanliness level, the DOP laminar Flow pass box is called "king". It can easily meet the high cleanliness standard of ISO Level 5, which means that the number of particles ≥0.5μm per cubic meter of air is no more than 3,520, and the number of particles ≥5μm is even fewer, no more than 20. Such a high level of cleanliness makes it the perfect choice for sterile drug production areas in the pharmaceutical industry, high-precision experiments in biological laboratories, and other places where cleanliness requirements are nearly demanding. For example, in the production of some high-end injectable drugs, any small dust particles may affect the quality of the drug, and the DOP laminar flow transfer window can ensure that the materials and equipment are transferred in an ultra-clean environment to ensure the safety and effectiveness of the drug. The cleanliness level of a clean pass box varies by type. The cleanliness level of the ordinary clean pass box is relatively lower, mainly used in places where the cleanliness requirement is not particularly extreme, such as the material transfer area of the ordinary food processing workshop, although it also needs to maintain a certain degree of cleanliness, relatively more dust particles are allowed. The air shower clean pass box can effectively reduce the introduction of dust particles by blowing and dusting items in the transfer process, and its cleanliness level can generally reach ISO 7-8, which can meet the clean needs of most electronic manufacturing workshops, general medical device production workshops, and other places. (3) Comparison of details of structure and function In the interlocking device, the DOP laminar flow pass box usually adopts an electronic interlocking device, which is sensitive and reliable. When a door is opened, the electronic induction and control system will immediately cut off the opening signal of the other door, ensuring that the two sides of the door will never be opened at the same time, effectively avoiding air cross-pollution in different clean areas. In addition to the electronic interlock, the clean pass box has a mechanical interlock device. Mechanical interlock is mainly achieved through the mutual restriction of mechanical structure, such as the use of pins, connecting rods, and other mechanical components, when one side door is opened, the mechanical structure of the other side door is locked and cannot be opened. Although mechanical interlock relative to electronic interlock, in terms of operational flexibility may be slightly inferior, it is good stability, some electronic equipment has special requirements or the environment is more complex places, which can also play an important role. In terms of detection port, the DOP laminar flow transfer window is equipped with a PAO dust port and a DOP detection port. The PAO dust port can periodically release aerosol particles of a certain size into the system, and then detect the aerosol concentration downstream of the HEPA filter through the DOP detection port to determine whether there is leakage of the HEPA filter and whether the filtration effect is up to standard. This detection method can find the problem of the filter in time to ensure that the purification performance of the pass box is always in the best state. Most of the clean transfer Windows do not have such a detection port configuration, and they mainly ensure the normal operation and clean effect of the equipment by regularly replacing the filter and daily cleaning and maintenance. For lighting and germicidal lamp configurations, the DOP laminar flow pass box is generally equipped with individually controlled lighting fixtures to facilitate the operator to observe the transfer of items in low-light environments. In terms of germicidal lamps, the ultraviolet germicidal lamps it uses usually have strong germicidal ability, and can effectively kill bacteria, viruses, and other microorganisms in the air and on the surface of items in the transfer window in a short time. The clean transfer window also has lighting and germicidal lamp configurations, but in some common clean pass boxes, the brightness of the lighting fixture may be relatively low, and the power and germicidal effect of the germicidal lamp may also be slightly weaker. (4) Small details of appearance and material In terms of appearance design, the DOP laminar flow pass box usually pays more attention to the overall fluency and line beauty, and the Windows are generally made of double-layer tempered glass of larger size, which not only has a clear vision but also can effectively prevent external dust and water vapor from entering the interior of the pass box. The handle design is also more ergonomic, more comfortable, and convenient to operate. The appearance design of the clean pass box is relatively more simple and practical, the size and style of the window and handle may vary according to different manufacturers and application scenarios, but generally more focused on meeting the basic needs of use. Material selection, both commonly used stainless steel materials. To ensure better corrosion resistance and stability, most of them use 304 or even higher grades of stainless steel, and the thickness of the plate is relatively thick, generally between 1.5mm and 2mm. In addition to stainless steel, some products will be made of painted steel plate material, which is relatively low in cost can also meet certain clean and beautiful requirements, and is suitable for some projects with strict cost control. |
