The filtration process in an industrial extraction plant

The industrial filtration process exploits different physical and mechanical principles with the ultimate aim of separating and cleaning the oily micro particles from the air flow, returning clean and healthy air into the working environment and into the atmosphere.

There are three main techniques of industrial filtration::

  • filtration with centrifugal separation
  • electrostatic filtration
  • mechanical-static filtration

The first principle exploits the centrifugal force of an impeller that re-condensates the micro particles of oil; in fact, according to the physical phenomenon of coalescence, the surface tension of the oil/water droplets tends to unite them, forming agglomerates of greater size and weight, which are more subject to the gravity force, making the totality of them return from the aeriform state to the original liquid state.

With electrostatic filtration, the flow of polluted air passes through special filter cells which polarize the oil mists by releasing a magnetic field. The immediate impact with another filter cell of opposite pole attracts them exactly like a magnet, blocking and separating from the air flow, purifying them. It should be noted, however, that, according to the strongest Italian regulations in force (D.D.U.O. n.12772 of 23/12/11), electrostatic equipment without HEPA filters is not in accordance with that norms.

With static mechanical filtration, the flow of polluted air passes through a sequence of filter elements, which retain particles and micro-dust with a diameter greater than the distance of the fibres making up the industrial filter, just like a sieve.

The process of oil mist filtration
Showcase: The process of oil mist filtration and smoke during machining processing

The maximum expression in terms of efficiency of the mechanical-static filtration principle is the HEPA filter. In order to obtain excellent results in terms of filtration and air health, it is necessary to use High and Very High Efficiency (EPA-HEPA) filters regulated by the European Standards EN 1822, as stated in the technical annex 32 - D.D.U.O. n.12772 of 23/12/11 of the Lombardy Region.

EPA / HEPA filters

The EPA filters of class E10 - E11 - E12 with high filtration efficiency, are suitable for clean rooms, pharmaceutical and mechanical industries, operating rooms and intensive therapies.

The HEPA filters with very high efficiency effective at 99,995% for particles > 0,01 micron, are suitable for tobacco fumes, oil combustion fumes, fine metallurgical fumes and viruses carried.

From an ecological point of view, the positive impact on the environment of an air cleaner with internal recycling mechanism is substantial. The company philosophy of AR Filtrazioni is not to focus the attention on problems, but on their total solution.

For more details please consult the website or the attachment of the Lombardy Region.