Publish Time: 2021-10-18 Origin: Site
At the heart of ductless fume hood, workstation or enclosure is a gas phase filtration system constructed with prefilters and main carbon and/or HEPA filters. Prefilters are installed at the inlets of every filtration system to remove gross material from the air stream and prevent main filter clogging. Main filters could be one layer of one kind, 2 layers of one kind or two layers of two kinds of activated carbon filters and HEPA filters. Carbon filters are the most popular variety installed in ductless fume hoods and enclosures to remove the chemicals from the air flow, while HEPA filters are used in the applications with particulate or aerosol to be captured as well.
The prefilter is an electrostatically charged fiber filter which effectively removes submicron particulates. Prefilter protects the main adsorption filters, carbon and/or HEPA, from smoke, acid mists and other micron particulates.
Xunling manufactures gas phase bonded carbon filters that are available using standard coconut shell carbon or chemically impregnated carbon for increased load capacity. Compared with traditional entirely granular carbon filters which have uneven distribution with hills and valleys in carbon and lead to breakthrough points and dust leakage, our unique bonded carbon filters have unparalleled advantages. Our filters utilize our unique bonded carbon filtration media to minimize potentially hazardous carbon dust found in traditional granular carbon filters. Our proprietary bonding process holds carbon in a predictable matrix, preventing carbon shift that can lead to “dead spots” common in traditional granular filters.
Our activated carbon has been soaked by special chemical additives, making it higher capacity for compounds that are not strongly adsorbed by general carbon, such as hydrogen sulfide, mercaptans, sulfur dioxide, chlorine, hydrogen chloride, nitrogen oxides, formaldehyde and ammonia.
HEPA (High Efficiency Particulate Air) and ULPA (Ultra Low Penetration Air) filters are the most popular varieties to isolate the aerosol and particulate in many applications, especially in pharmaceutical enterprises, hospitals, fine chemistry plants, CDC and forensic laboratories. HEPA filters can be used to contain particulate with diameter as small as 0.3 microns while ULPA filters for smaller particulate up to 0.1 microns diameter.
HEPA filters are produced with high quality fabric materials and in sophisticated processes, which can capture aerosol and particulate at 99.997% or higher collection efficiency for 0.3 microns diameter. This ensures HEPA filters effectively block the most of fine powders and ducts as well as the biological aerosol containing toxic bacteria and viruses.
In case that the aerosol or particulate is too small for HEPA filter to remove, ULPA filter which can capture aerosol and particulate at 99.9995% or higher collection efficiency for 0.1 microns diameter, may be an ideal alternative solution.
In the HEPA-Carbon filtration, HEPA filters remove the smaller particulate in the airflow being primarily cleaned by the prefilters and then entering the bonded carbon filters to have the chemicals in the airflow adsorbed. The HEPA and bonded carbon filters are monitored separately by different specific detectors as installed in the single layer systems. Please notice only for the applications simultaneously emitting toxic chemical gases and particulate are the HEPA and bonded carbon filtration imperative.
Here is a fact that with the using time moves, the performance of filters gradually declines and they should be replaced once the filters are saturated to ensure the safety and reliability of the ductless equipment. And it is imperative to notify the operator. The gas detectors monitor pollution in real-time, together with temperature, humidity and filters loading detectors to monitor comprehensively. The alarming system will let you know visually and audibly in advance when filters need a replacement.
Xunling ductless fume hoods, workstations and enclosures are equipped with all these three types of filters, to form a combined filtration system of much higher adsorption capacity. We strongly suggest you tell us your application requirements in detail before you order our units. Our application specialists will recommend the most appropriate configurations based on the information you provided to ensure the ultimate safety, the best effects and the highest efficiency.