Filter System - Thermo Scientific Safe 2020 Operating Instructions Manual

Operating Instructions Safety Cabinet Safe 2020 / Maxisafe 2020
4. Unit description
• Position monitoring
The position sensors monitor the position of the front
cover as well as the movement of the front window; it will
indicate when the front window is in the working position.
• Performance Factor
The Performance Factor (PER) is a value that indicates the
safety state of the safety cabinet. This value is calculated
from data determined by the safety system and from
values captured empirically by service personnel during
safety checks. This data is entered into a parameter list of
the control software and interconnected. The result can be
indicated by the display.
4.3

Filter system

Model Safe 2020:
Fig. 4a: The filter system consists of two HEPA filters [2] and
[5] for the circulating air and for the exhaust air and of a coarse
filter for the aspired air.
HEPA filters: Room air [10] is drawn into the sample
chamber through the working opening. In the air duct, room
air and the downflow within the chamber [7] are then blended
to make up the blend air [9]. The blend air is then:
• filtered proportionally by the downflow filter [5] and
supplied as ultrapure air [6] evenly into the sample chamber
of the device,
• filtered by the exhaust air filter [2] and released as
ultrapure air [1] to the exterior of the device.
Inlet air protection: The air duct between the sample chamber
and the device plenum has an inlet air protection [8] below the
working surface to prevent coarse particles from entering the
plenum where they may impair blower [3] und [4] and filter
functions.
18
Fig. 4a
Filter system with downflow
filter and exhaust air filter /
model Safe 2020