Ifunction At\Jd Description Of The Sterilga.t~D'ii Cabinet; Airflow Inside The Biological Safety Cabinet; S Peg 1Cahons; Fig. 1 Airflow Inside Cabinet - Baker SterilGARD II SG400STD Operator's Manual

I -FUNCTION AND DESCRIPTION OF THE STERILGARD®II
CABINET
The SterilGARD"'II is a biological safety cabinet
of original design. It features vertical laminar
airflow and a front access opening. The ru1it is
designed to protect not only the environment and
the people using the cabinet, but also the product
within from airborne contaminants.
Airflow Inside the Biological Safety Cabinet
The SterilGARD® II cabinet features The Baker
Company's zoned airflow principle. See Fig. 1.
The stainless steel metal diffuser just below the
supply filter creates a faster airflow at the front of
the work zone than at the center. The protective
faster airflow in front makes an extremely
effective air barrier.
A feature of the unique Baker design is the high
volume return air slots, which maximize the
cabinet's protective capability. It is generally
accepted that maintaining containment and a
particle free work area is most difficult in the area
in whim airflow turbulence is greatest- at the
intersection of the side walls, the front access
opening and the work surface. Turbulence
caused by friction will also be found along a
cabinet's side walls. ln cabinets without high-
velocity return air slots, this turbulence may allow
contaminants to escape from the work area, or it
may make it possible for unfiltered room air to
enter the work area.
The Baker high-velocity retu.m air slots are
located along the side walls of the work area. Air
is dravv:n into the slots at very high speed,
preventing the escape of particulates and
ensuring that no unfiltered air enters the work
area. Additional hjgh-velocity return air slots are
located at the top and sides of the viewscreen to
prevent gases, \'·apors or particulates from con1ing
up behlnd the vie\vscreen and escaping into the
laboratory. In the same \va.L they' prevent room
air .frorn do>A'T1
behJnd tl1e \/ie'i\rscreen
and contarninatLTlg the work area.
1
P!enum
~
~
<}
t ;;J
-
Blower
v v v
v v v
t::J;;J
-
Room air
negative pressure
+
Contaminated air
positive pressure
<>
Clean air
.qp.
Contamina~ed air
negative pressure
Exhaust
)I>
filter
Supply
filter
~
8" access
----
opening
Fig. 1 Airflow Inside Cabinet