Filtration Table of Contents
In figure 1,below, a fan draws dust, smoke
and other particulate into and through the electronic air
cleaner. Larger particles are trapped by a Pre-filter
Screen / Filter while smaller particles pass through into the
Charged Section, where the particles are positively charged
by a series of large diameter wires often made of tungsten.
The charged particles are then drawn into the
Collection Section which is composed of a series of positive
charged plates which propel the positively charged particles
into a series of negatively charged plates, which attract and
"hold" the particles.
Collected pollutants which are collected onto
the negatively charged plates are removed at cleaning.
Often, cleaned air is then circulated through a Charcoal
Filter where moisture / odors are absorbed.
Reference: ASHRAE Handbook of
Fundamentals, 1985; ASRAE Guide and Data Book application,
1987. Natural and Mechanical Ventilation, 1981