Hepa Filters; Paper Catch Grids - Thermo Scientific 1300 Series User Manual

Section 1
Description

HEPA Filters

Paper Catch Grids

1-4 1300 Series A2
The filter system consists of two HEPA filters for downflow (supply) and
exhaust air.
Room air is drawn into the sample chamber through the work position
window opening. The room air is drawn into the negative pressure drain
pan air duct, then
pulled into the air
plenum in the top
portion of the cabinet.
The room air is mixed
with recirculating
HEPA filtered air from
the chamber, and
filtered proportionally
by the downflow and
exhaust filters. The
filtered air is then
supplied as ultra-pure
air into the sample
chamber of the unit,
and exhausted as ultra-
pure air into the room
environment, or into
an external exhaust
system via an exhaust
transition.
Sectional paper catch grids are installed beneath the work tray in the air
duct between the inner and outer back wall of the unit. These grids
prevent large items such as paper towels and tissues from entering the
plenum where they may impair the function of the blowers or the filters.
The grids can be easily removed for cleaning.
Room air
Figure 1-2. Airflow Filtering System
Ultrapure air
Exhaust air filter
Exhaust blower
Supply blower
Supply filter
Ultrapure air
Downflow
in chamber
Blended air
Paper catch
screens
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