With filters being exposed to a much broader range of particle sizes, which requires higher levels of filtration maintenance, filter technology manufacturer Freudenberg Filtration Technologies (FFT) says attention should be drawn to the new ISO 16890 standard for filter testing and assessment.

With the new standard, implemented at the end of last year, filter efficiencies will be determined with regard to the particulate classes PM1, PM2.5 and PM10, says FFT MD Andrew Hersey.

“The old EN 779 test standard applied exclusively to the particle size 0.4 μm. ISO 16890 considers a range of particle sizes between 0.3 μm and 10 μm. With the introduction of the new ISO 16890 standard, actual operating conditions will be more effectively taken into account,” Hersey says.

FFT offers a maintenance service to prepare filtration systems for extended shutdown and quick start-up after the holiday season, he adds.

“During filtration system maintenance, the filter differential pressure status needs to be checked to determine the filter’s estimated life span. The maintenance team needs to remove and clean the filter unit, inlet and out sections, as well as clean filter elements and wash [them] in the case of fully washable FFT Viledon filters.”

Further, the differential pressure instrumentation needs to be cleaned and maintained, while the fan and motor units need to be assessed and maintained in accordance with original-equipment manufacturer maintenance instructions.

Hersey explains that, before starting a filtration system after the holiday season or long periods during which the system was offline, certain steps should be followed. “The intake of the filtration system should be free of any obstructions, the filter elements should be installed and sealed, and all of the electrical and rotating equipment should be secure and installed correctly.”

To further ensure that the process is done effectively, the FFT Service division offers a service and maintenance proposal to ensure that all systems installed on a specific site are maintained correctly during the production span, but are also prepared and maintained during the off season.

However, he points out that FFT installations of industrial applications are in use 24/7 and would be shut down only for critical maintenance.

Extended Work Times
Hersey notes that, as filtration systems are nonoperating for an extended period, filtration systems face the risk of degeneration in terms of filters being destroyed by vermin, thus facing the possibility of dust bypass and zero filtration efficiency.

“One could isolate the intake or open ends of such systems to ensure that this does not occur. Also, bearings of mechanical and electrical equipment that have not been operational for extended periods might fail, owing to degenerated lubrication, and should be inspected prior to start-up.”

With regard to filter elements not being properly maintained, Hersey mentions that they are almost always prone to overloading – leading to filters reaching the maximum allowed differential pressure much sooner, subsequently causing filter failure and, ultimately, electrical circuit burnout.

Such failures would lead to the pollution of the workspace or atmosphere and catastrophic failures would lead to excessive contamination of workspaces or areas that are intended to remain clean, and can affect the staff working in those areas, he explains.

“One could imagine the effects of a high efficiency particulate filter bursting in a laboratory or hospital, contaminating the area with high concentrations of bacteria, owing to inadequate maintenance,” he warns.

Hersey points out that the FFT Viledon filter elements are manufactured from synthetic materials, which mitigate natural degeneration. He emphasises that care should still be taken when using the FFT Viledon filter elements, noting that, for example, they should not be exposed to the elements unnecessarily.

FFT is working with an industry leader in the hard-rock mining sector to develop and install a vacuum-based filter system. The company also provides its services, through branches and exports, in Tanzania, Botswana, the Democratic Republic of Congo and Ghana.