Most industrial ventilation systems in factories, data centers, and office buildings adopt a return air design where polluted air from the indoor production area is filtered through the regeneration filter and fine particles are removed before returning the air to the working environment. Returning the air in this way helps to provide clean air to the room that meets hygienic specifications and occupational exposure limits for hazardous agents in the workplace.
In normal working environments, there can be more than 500,000 fine dust particles (including PM2.5) per cubic inch suspended in the indoor ambient air. The surface of the particles has a developed pore structure, making it is easy to adhere to bacteria and viruses of nanometer size nominally less than 0.1µm (1/15000 of hair diameter). These particles combined with bacteria and viruses enter the trachea through breathing and deposit in the lungs, which can seriously affect human health. Improving the filtration efficiency of the return air system together with correct maintenance of the central air-conditioning ventilation system, can help to reduce the chance of cross-infection caused by bacteria or viruses.
Industrial air conditioning and ventilation system efficiency for mixed air or fresh air filtration can be improved with Donaldson Nanofiber technology filter cartridges. Donaldson provides improved filtration efficiency, long-term low-pressure operation, no washing, and increased filter life. Donaldson's Nanofiber technology filter cartridge for the regeneration filter can be used to improve the efficiency of filtering mixed air or fresh air. Donaldson Nanofiber technology can also run at low pressure for a long time without washing, thereby greatly extending the life of the filter cartridge and creating additional economic value for customers.
Donaldson filter media is covered with a layer of Nanofibers, that is, an Ultra-web® membrane on the conventional filter substrate. According to the ASHRAE 52.2 test results of the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Donaldson Ultra-Web® filter cartridges can achieve MERV15 dust removal efficiency. According to GB / T14295-2008 standard test results, Donaldson ULTRA-Web® filter cartridges can achieve sub-high filtration efficiency and can completely filter fine dust particles (including PM2.5) in indoor air.
Donaldson filter cartridges can block and filter out small bacteria-containing droplets with a particle size of about 3um-100um to ensure that the plant air is safer and cleaner.
Tiny droplets in the ambient air, like mist droplets, with a particle size of about 3 um-100um, can be captured by Donaldson filter cartridges. Smaller dust particles can also be captured in the larger interception area in Donaldson Nanofiber Ultrafine fiber layer. This can enhance filtration efficiency through molecular adsorption or similar electrostatic adsorption.
Donaldson does not recommend washing the filter cartridge with water. Purchasing high-quality filter cartridges improve air filtration efficiency and ensure air safety.
When a domestic filter cartridge for an air-conditioning return air system uses water washing to extend service life, the filters' initial filtration efficiency is gradually reduced. After four washes of a brand filter cartridge by Donaldson Labs, the initial filter efficiency of the filter cartridge is 27.34%, which is far lower than the minimum requirement of 35% corresponding to the initial filter efficiency of the same level standard. At the same time, the resistance of the filter cartridge increases and the dust holding capacity decreases after each washing.
The conclusion is that it is not recommended to wash the filter cartridge with water. Water washing not only destroys the fibrous tissue and reduces the filtration efficiency of the filter cartridge, but also stirs up the dust that may contain viruses on the surface of the filter cartridge that are potentially hazardous to cleaning staff and the environment. When washed, particles will also enter the water where bacteria and viruses can contaminate water bodies and cause further negative effects.
Compared with other brands of filter cartridges, Donaldson filter cartridges have the following advantages:
- High filtration efficiency: The filtration efficiency can reach MERV15, which meets the hygienic standards of indoor air and effectively optimizes the health and health of the work environment of employees.
- Long-term low-pressure operation: can greatly reduce the power consumption of the induced draft fan and the consumption of compressed air, and reduce the power consumption of the air compressor.
- Less maintenance: means that the entire system can continue to run, improve the production efficiency of the enterprise, and reduce the economic loss caused by frequent startup and shutdown.
- Long service life: can reduce the number of replacement of filter cartridges, reduce the number of workers exposed to dusty environments (including bacteria or viruses), and help protect human health.
Donaldson air-conditioning filter section has high filtration efficiency and less maintenance work. One filter section can replace the traditional primary and intermediate-effect filter system; because of its nano-layer, it can remove dust and viruses attached to the surface and fly. The foam is completely intercepted, and the filtered air meets the indoor cleaning requirements. At the same time, because of the surface nano-layers, the dust is directly blocked on the surface of the filter material and easily peeled back. It can maintain a very low operating pressure difference and maintain a relatively low Long life, usually can be used for 2-4 years. For new projects, Donaldson can provide customized services such as the overall design of dust removal and equipment selection (including filter cartridges). For filter cartridge replacement projects, it can provide products with better performance and reduce the total cost of ownership of customers.
