The Guard A2 biosafety cabinet incorporates a variety of intelligent technologies, including the ability to automatically identify the relationship between power and air volume and static pressure, a mechanism to automatically sense changes in air flow and static pressure, and the ability to automatically adjust wind speed (3A). This integrated design aims at expanding the system static pressure range and conserving the total gas flow rate and the airflow velocity vector, avoiding the actual harm to personnel and products caused by the fluctuation and monotonous decline of the total gas flow rate, so as to ensure the safety of personnel and products in the microbiological experimental operation.
Intelligent Technology and Biosecurity
● The comprehensive application of 3A technology is the key design strategy to achieve the total gas flow conservation and the flow velocity vector conservation of the system, and is also an effective means to correct the flow fluctuations and excessive monotonic decline. In the biosafety cabinet system, the performance of the barrier is highly dependent on the maintenance of kinetic energy, especially at the personnel protection level, the stability of kinetic energy is directly reflected by the velocity vector of the inflow air flow. When the airflow fluctuates or decreases monotonously, the kinetic energy of the system will show a downward trend. By quantitative analysis, when the total flow fluctuation reaches ± 20%, the average flow velocity of the system will deviate significantly to the level of II A1 (0.4 m / s) or less. In addition, when the inflow airflow velocity vector decreases by 10%, the kinetic energy of the system will be less than the spraying velocity vector (0.5 m / s) in the microbial challenge, which may increase the risk of human hazards. It is important to note that the risk of human hazards will be adjusted as the inflow airflow velocity vector deviates from the minimum flow rate (0.5 m / s). It should be emphasized that both fluctuating airflow and excessive monotonic decline are inherent risks of the system and can cause potential harm before the system alerts. The Guard A2 biosafety cabinet successfully eliminates airflow fluctuations by lifting the internal technology of the system, and controls the monotonous decline of airflow within 3%, significantly improving the stability and safety of the system.
● The physical principle of the monotonic descent of the system airflow is that as the adsorbed particles in the hepa filter accumulate, The resistance of passing air increases gradually, which causes the fan to convert more kinetic energy into static pressure energy in the process of adapting to the change of resistance of HEPA filter, which leads to the decrease of system kinetic energy and the increase of static pressure energy. Therefore, the function of "automatic identification of the relationship between power and air volume, static pressure, automatic induction of gas flow and static pressure changes, automatic adjustment of wind speed" aims to expand the dynamic range of system static pressure, and reduce the conversion of kinetic energy to static pressure energy.
It is worth noting that a monotonic decrease of 10% of the system's total air flow rate is regarded as an important risk point, because the system will face varying degrees of personnel hazards when the nominal value of the inflow air flow rate is less than 0.54 m / s. It must be emphasized that in the field of medical clinical testing, personnel pollution incidents caused by excessive decline in total air flow have occurred many times, and these cases should cause us to reflect deeply. In addition, from a technical perspective, this risk pattern highlights a mismatch between wind turbine performance and system requirements.
The Guard A2 biosafety cabinet has been designed to increase the system's static pressure limit to 300 pa, demonstrating four times the static pressure increment capability of existing technology. At the same time, the airflow velocity vector reduction is effectively controlled within -3%, which fully demonstrates the excellent performance of the Guard A2 biosafety cabinet in terms of airflow velocity vector stability and microbial isolation barrier capability.
● In the vertical section of the front window of the system, it can be found that the airflow velocity vector in the lower region is significantly higher, and in sharp contrast, the airflow velocity vector in the upper region is significantly lower, showing a significant asymmetry. It is particularly alarming that the airflow velocity vector along the upper edge of the opening reaches a minimum value. This relative minimum inflow airflow velocity (0.5 m / s) is practically equivalent to the formation of an airflow cavity, which exposes the inadequacy of the system's airflow organization structure to meet the requirements of personnel protection. It is therefore reasonable to infer that this area is a critical point of risk to the safety of personnel. To meet this challenge, the Guard A2 Biosafety Cabinet introduces for the first time a laminar descending air curtain design. This innovative technology effectively fills the void in the inflow air flow in the system, with a speed vector controlled within the range of 0.5 m / s ± 0.05 m / s and perfectly integrated with the inflow air flow. This is designed to be an efficient and reliable means of preventing the escape of microorganisms.
● In the safe operation of negative pressure airflow enclosure, once leakage occurs, its remarkable characteristic is that the external airflow penetrates into the enclosure, which causes the inflow airflow velocity vector to decrease obviously. This phenomenon highlights the significant increase in the probability of personal contamination when the integrity of the cabinet is compromised. Unmelted cabinet materials, such as stainless steel inner wall and surface coating of carbon steel outer wall, because of the unmelted characteristics and there is a connection gap; At the same time, the spot welding connection between the two intersecting sides in the external wall of the cabinet and the silica gel plugging technology may cause leakage due to stress during the handling process. For systems equipped with butterfly valves, the exposure gap caused by the butterfly valve shaft passing through the cabinet may also be a potential risk point for leakage. Although these gaps may not be visible visually, they are real enough to cause a severe drop in inflow.
In order to effectively reduce such risks, the Guard A2 biosafety cabinet uses a highly complete stainless steel seamless cabinet structure to ensure that the inner and outer walls of the cabinet form a seamless integration of stable construction, thereby reducing the probability of personal contamination to a minimum. In addition, the Guard A2 Biosafety Cabinet has significantly improved the design of the operating chamber airflow structure, Designed to increase the air quality in the operating cabin to Class 3 @ 0.3 μm, ensuring that the entire operating cabin constitutes an effective area to protect the product and to minimize the bacterial particle population. This improvement provides a safer and more reliable platform for the biological industry and its research field.
