DOCUMENT NO: M40 ISSUE NO: 3 ISSUE DATE: 11/07/18
4
PRINCIPLES OF OPERATION
Air is drawn into the cupboard at the working aperture
A
below the hinged clear acrylic
front window, at a velocity high enough to ensure entrainment of any fumes/odours given
off by the processes carried out within the cupboard.
The fumes from within the cupboard are drawn either upwards as in the case of lighter
than air fumes
B
to the extract slot
D
, or drawn across the work surface to the secondary
extract slot
E
created by the back baffle, as in the case of heavier than air
fumes/particulates*
C
.
The combination of extract slots
D
and
E
ensure that all fumes/particulates* are carried
by the moving body of air to the pre-filter
F
and
main filter
G
to be absorbed before being
expelled by the exhaust fan
H
as clean air
J
The fan
H
, which is mounted above the main filter exerts a negative pressure on the
internal space within the cupboard. This in turn pulls external air into the cabinet through
the working aperture
A
and keeps a constant circulation of pre-filtered clean air passing
through the cupboard whilst ensuring that fumes/particulates* are trapped and adsorbed
by the main filter.
*dependent on main filter type fitted.
