High-efficiency exhaust unit

The following is a detailed introduction to the high-efficiency exhaust unit:
Definition and Usage
Definition: A high-efficiency exhaust unit is a device used for processing and discharging air. It can effectively filter, purify, and control pollutants in the exhaust air, ensuring that the discharged air meets relevant standards and requirements.
Application: It is widely used in various high-risk or highly isolated places, such as biosafety laboratories, hospital isolation wards, pharmaceutical factories, nuclear power plants, etc. In these places, it plays a crucial role in preventing the leakage of harmful biological factors, chemical substances, or radioactive materials into the external environment, and protecting the safety of personnel and the environment.
Structural composition
The box body: It usually adopts an airtight design. The main body is an airtight box body, with rounded corners around it, which can withstand certain pressure and prevent internal gas leakage. The box is also equipped with aerosol injection ports, sampling ports, interfaces for disinfection equipment, etc., facilitating various operations and tests.
Filters: Generally, they include primary filters and high-efficiency filters (HEPA filters). The primary filter can filter out larger particles of dust and impurities, protecting the high-efficiency filter. High-efficiency filters can achieve a filtration efficiency of over 99.97% for tiny particles, such as 0.3μm particles, effectively intercepting pathogenic microorganisms, dust, and other pollutants.
Scanning device: It can perform in-situ scanning leak detection on high-efficiency filters. If line scanning technology is adopted, it should be as wide as the air outlet surface of the filter, and the sampling port should be in a line shape. This can quickly and accurately detect whether there is a leak in the filter, avoiding human errors caused by manual scanning.
Disinfection equipment: Equipped with gas disinfection ports, disinfection verification ports, disinfection pressure relief ports, etc. It can adopt the local gas circulation disinfection method or the overall laboratory gas circulation disinfection method to thoroughly disinfect the filter and the interior of the box, ensuring the elimination of residual pathogenic microorganisms.
Differential pressure detection instrument: It monitors the differential pressure changes of the filter in real time. By monitoring the pressure difference at both ends of the filter, the degree of clogging of the filter can be determined, so as to carry out maintenance or replacement of the filter in a timely manner.
Biosafety airtight valve: Installed at the air inlet and outlet of the exhaust unit, it can achieve safety isolation and protection of the ventilation duct during system operation, fault shutdown, or disinfection process, preventing gas backflow and pollutant leakage.
Working principle
Filtration principle: Air containing pollutants enters the high-efficiency exhaust unit from the air inlet. It first passes through the primary filter to remove larger particles of impurities, and then through the high-efficiency filter. By taking advantage of its special fiber structure and filtration mechanism, it intercepts, adsorbs, and filters the tiny particles and pathogenic microorganisms in the air. The purified air is then discharged from the air outlet.
Disinfection principle: When disinfection is required, close the biological airtight isolation valves at both ends of the unit, connect the disinfectant generator and the circulating disinfection device to the gas disinfection port of the high-efficiency exhaust unit, start the disinfectant generator and the circulating disinfection device, and let the gas disinfectant circulate back and forth in the box, penetrating the high-efficiency filter, thereby achieving disinfection and sterilization of the filter and the interior of the box.
Selection and installation
Selection: Choose based on factors such as the biosafety level of the usage site, air volume requirements, and spatial layout. For biosafety level 3 and 4 laboratories, it is usually necessary to select pipe-type exhaust high-efficiency filtration devices with in-situ disinfection and leak detection functions. According to the air volume and specific needs of the laboratory, various combinations of single-unit and multi-unit, single-stage and double-stage filtration can be adopted.
High-efficiency exhaust air filtration devices for biosafety level 3 and 4 laboratories should be installed at the indoor exhaust air outlet or immediately adjacent to it. During installation, attention should be paid to the placement and fixation method of the equipment to ensure its firmness and reliability. At the same time, it is necessary to ensure that the replacement and detection space of the box filter is at least 1.0 meters. Use flexible connection sleeves to connect the air inlet and exhaust outlet of the high-efficiency exhaust unit to the laboratory pipeline, respectively, and secure them with clamps.