Mechanical Filters
Mechanical air filters are also called media air filters. They use some
filter media to remove particles from the air stream. At the microscopic
level the filter media consists of an interlocking network of fibers, which
is quite porous. The porosity of the media is necessary and is responsible
to allow air to pass through the unit with minimal pressure drop. The
particles in the air stream is caught by the web, formed by the interlocking
fibers of the material.
Characteristics
The main characteristics of mechanical filters are:
- These types of filters use some kind of media to trap the impurities.
- Before the air is inhaled by an individual, the air is forced through
a specially designed screen to trap allergens like dust mites, pollens,
pet dander and other particles.
- They are also useful in capturing the irritant particles like tobacco
smoke, which can create allergy.
Principles of Filtration
All the filtration technologies are based on some principles or other. In
mechanical air filters, particles come into contact with the surface of
fibers in the filter media and cling to the fibers. It is totally a
mechanical process and don't require any chemical involvement. All
mechanical air filters operate on two basic filtration principles. First is
primary air filtration or impingement of the dust on the media itself. And
the second one is secondary air filtration, which removes or filter out
smaller dust particles.
Maintenance
The mechanical filters purify the air by trapping the impurities present in
the air. The trapped particles are accumulated in the filter and constrict
the efficiency of the filter. It will lead to problems in free air flow,
thus depreciation in performance of the filters. Due to these limitations,
the mechanical filters require proper care and maintenance. Some of the
mechanical filters are washable, which make the maintenance easy. Those
which are not washable require to changed after specified period of use.
Types of Mechanical Filters
Mechanical air filters can be man made or natural fiber filter. The most
common mechanical filters, which are widely used are:
