Technical features of 3A2C
The 3A2C technology of the Guard A2 Series Biosafety Cabinets is significantly characterized by its innovative adjustment of the relationship between the system gas flow and static pressure characteristics, discarding the limitations of the traditional technology where the decrease of the total gas flow is less than 10% and the fluctuation range of the air flow is ±20%. This technology achieves the constant maintenance of the total gas flow and the air flow velocity vector by optimizing the system design and control strategy. The technology increases the service life of the HEPA filter of the safety cabinet to more than four times the current standard requirements, reflecting extremely high durability and stability.
The performance characteristics of the Guard A2 series biosafety cabinet are the linear relationship between static pressure and gas flow rate, that is, the total gas flow rate of the system is controlled in a small range when the static pressure increases monotonously, showing excellent airflow stability. At the same time, the series safety cabinet has a high static pressure upper limit, which can maintain a constant flow rate and speed vector over a wider pressure range.
Particularly important features are as follows: From the initial activation of the system to the end of the service life of the HEPA filter, the deviation degree of the velocity vector of the inflow air flow and the downflow air flow is always maintained at an extremely low level. This feature effectively reduces the risk of microbial contamination and provides a safer and more stable working environment for biological laboratories.
In summary, the 3A2C technology used in the Guard A2 series biological safety cabinet, with its unique automation function and conservation principle, provides a safer and more stable working environment for biological laboratories, effectively reducing the risk of microbial contamination of personnel and products.
Effectiveness and Economics
The technical effectiveness and economics of 3A2C are reflected in the following aspects:
First of all, in terms of system performance, the total static pressure range of the technology is excellent, its static pressure lower limit is controlled at 100 Pa ± 10 Pa, and the static pressure upper limit is not less than 300 Pa, which is more than four times higher than the current standard requirements. This significant improvement not only enhances the stability and reliability of the system, but also ensures outstanding performance in a variety of operating environments.
Secondly, in terms of gas flow management, the 3A2C technology ensures that the total gas flow is conserved within the total static pressure of the system. This feature effectively ensures the balance between the inflow velocity vector and the downdraft velocity vector, thus eliminating the possible personnel hazards caused by the total gas flow rate dropping too much, and significantly improving the safety and reliability of the system.
In addition, the technology also gives the system an isolation barrier function, making its capabilities more effective and reliable. The implementation of this function not only improves the protection performance of the system, but also enhances its ability to cope with complex environments.
Finally, from an economic point of view, the application of 3A2C technology significantly reduces the frequency of HEPA filter replacement, effectively reducing equipment maintenance costs. At the same time, the detection frequency and the detection cost are reduced, and the overall economic benefits are further improved.
To sum up, 3A2C technology, with its excellent performance, excellent safety and reliability, and significant economic advantages, is a strong support for biosafety laboratory.
Adding the Second Isolation Barrier-Layer Descending Air Curtain
The laminar-type descending air curtain is an important part in the design of reshaping the airflow organizational structure of the Guard A2 series biosafety cabinets. It is located on the inner side of the perspective glass, within the space from the air inlet grille to the orthogonal projection area. The airflow of the air curtain flows from top to bottom, and the velocity vector along the inner side of the upper edge of the front opening is 0.5 m/s ± 0.05 m/s. After the convergence of the air curtain and the inflow airflow, they pass through the front grille and enter the negative pressure zone. In previous designs, the spatial range from the air inlet grille to the orthogonal projection area was the blind zone of the descending airflow. The airflow of the laminar-type descending air curtain is taken from the air purified by the high-efficiency air filter, and the air quality is better than level 3 @ 0.3 μm.
Causes of inflow air voids
Structure of New Downdraft Airflow Structure
The newly designed downdraft airflow structure of the Guard A2 series biosafety cabinets is elaborately crafted to significantly reduce the potential risks brought about by the traditional "loop" airflow structure. The core design concept is to establish a work platform with downdraft airflow covering the entire area, thereby enhancing the air quality in the working area to level 3 @ 0.3 μm. Compared with the original level 5 @ 0.5 μm, it has witnessed a remarkable improvement, ensuring a sterile environment within the working area. The realization of this design goal relies on the construction of a downdraft airflow system with full coverage, the optimization of HEPA filter performance technology, the achievement of zero leakage (at the junction of the HEPA filter frame and the cabinet) control technology, and the comprehensive application of current sharing technology.
Guard A2 Series Biosafety Cabinet Cabin Features
●The cross-section of the operating compartment is completely covered by the HEPA filter element (with no downdraft blind area).
●There is zero leakage between the filter and the cabinet structure to ensure that the airflow filtered by the HEPA filter is pure.
●Filter bacterial particle groups @ 0.5μm to 10μm threshold size.
● Class 3 @ 0.3 μm air mass.
Rigorous Operating Cabin Air Quality Inspection and Evaluation Procedures
●Sampling point: the intersection point 30mm from the rear side wall and the left side wall respectively; 150 mm from the inside of the front window perspective glass, 30 mm from the intersection of the left and right side walls; Geometric center of mesa; A total of 5 sampling points. Sampling was performed at a cross section 300 mm upward of the table.
● Sampling rate: ≥ 28.3L.
● Sampling volume: The amount of air (196.08 L) that can collect 20 pc of particles is corrected to 200 L.
Analysis: The Defects of the "Loop"-Shaped Airflow Structure in the Cross-Section
The existing planar organizational structure of the operating chamber of Class II biosafety cabinets is equivalent to a "loop" shape. The middle area between the two "square" shapes is the downdraft blind area. See the view:
● The shaded areas are the specific physical spaces where aerosols can be detained. In this region, the existing "hot wall effect" provides the prerequisite for aerosols to rise within this spatial range. Meanwhile, due to the airflow blind area at the top of the shaded area, an airflow vortex is formed, and aerosols move along with it and the concentration accumulation occurs here. Some aerosols, after being affected by the downdraft, are introduced and landed, which may lead to the contamination of the products.
The inherent filtration efficiency of the HEPA filter in the biological safety cabinet is 99.99% @ 0.3μm, but the actual air quality in the operating chamber is reduced to 5 @ 0.5μm, which constitutes a technical obstacle to the application of biological aseptic work.
Emphasis needs to be placed on the scope of the product protection area inside the operation chamber. However, due to the existence of non-protected product areas in the same space, the actual scope of product protection is reduced. This airflow organization not only increases the complexity of management, but also enhances the risk of product contamination.
Stainless steel seamless integrated cabinet structure
The biosafety cabinet, as a negative pressure airflow enclosure, has a notable feature in an incomplete state of the cabinet that external air penetrates unexpectedly into the cabinet environment through leakage points. This leakage mode directly causes a reduction in the inflow air volume and velocity vector, thereby increasing the risk of personnel contamination. To effectively avoid such risks, the Guard A2 series biosafety cabinets adopt a seamless stainless steel integrated cabinet design to ensure that the cabinet is equivalent to a negative pressure pressure vessel, thereby significantly improving the safety performance of the system. It is worth mentioning that this design feature of the Guard A2 series biosafety cabinets, namely the seamless integration of the inner and outer walls, is the key to its excellent performance.