Explosion Protection; Method 1: Explosion Relief Venting; Method 2: Explosion Suppression System; Pre Installation - Nederman FlexFilter EX Manual De Instrucciones

Chapter 13 Electrical installation
EN
tion.
Figure 21 shows the components of the TVFD EX
Valve.
1 Upper Slide Valve, USV
2 Lower Slide Valve, LSV
3 Container
4 Outlet
5 Slide Valve Covers (x4)
6 Terminal box Cover
7 Terminal box
8 Nipple (compressed air)
9 Stop switch
10 Manometer
11 Reset button
12 Silenced exhaust regulators (regulates valve clos-
ing speed)
13 Quick exhaust valve
14 Manual override
Figure 22 shows a compressed air diagram for the
FlexFilter EX with TVFD.

9 Explosion protection

The CE and ATEX markings on the FlexFilter EX en-
sure both a high level of safety and protection against
the ignition of possible explosive atmospheres. How-
ever, if an explosion occurs due to misuse, insufficient
maintenance or faulty installation, the FlexFilter EX is
equipped with additional protection methods to avoid
dangerous pressure build-up in the filter.
FlexFilter EX comes equipped with either an Explosion
Relief Panel or an Explosion Suppression System.
The Suppression System is normally only used if vent-
ing is impossible due to the placement of the filter,
dangerous material properties or resulting flame and
pressure risk area.
FlexFilter EX is not a barrier and must not be used in-
doors. Outdoor use with explosion relief venting. Feed
out into a big bag or open container (enclosures that
cannot retain pressure).

9.1 Method 1: Explosion relief venting

The harmful effects of an explosion are minimized by
venting the pressure and flame of the explosion via
a relief panel. In case of an explosion, the resulting
flame and pressure escape out the relief panel which
must be directed to a safe, unmanned area. This area
will be referred to as the "risk area"
The risk area must be clearly marked, for example
with a fence, warning lines and signs, and is to be off-
limits during the time the filter is in operation. The
area shall be free of any flammable or combustible
36
FlexFilter EX
for detailed informa- material or other things in danger of being damaged
by the flames and explosion pressure.
The general size of the risk area with or without de-
flector (accessory) is shown in
rule the following dimensions apply:
A 12 m (39.4 ft)
B 3 m (9.8 ft)
C 5 m (16.4 ft)
D 6 m (19.7 ft)
E 6 m (19.7 ft)
F 6 m (19.7 ft)
G 6 m (19.7 ft)
The risk area can extend beyond the above-
given values. The final risk area must be evalu-
ated with regards to affecting factors found in
standard EN 14491.
9.2 Method 2: Explosion suppression
system
With an Explosion Suppression System, the early
stage of an explosion is detected with optical and/
or pressure devices, and an extinguishing agent is
quickly dispersed into the filter. The suppression of
the explosion is initiated in an extremely short time
after the explosion's detection (in milliseconds), and
stops the pressure rise and extinguishes (suppresses)
the flame/flames of the explosion.
This ensures that the filter is not stressed to a danger-
ous level by the explosion.
The key components of the Explosion Suppression
System are:
• An explosion detection device (pressure/optical)
• Computer operated control unit
• Action elements such as pressure cylinders with ex-
tinguish agent contained with an extra fast opening
valve.
Detailed information regarding system function, op-
eration and maintenance can be found in the suppres-
sion system manual.

10 Pre Installation

WARNING! Risk of personal injury
Always use proper lifting equipment and pro-
tective gear.
WARNING! Risk of personal injury
Explosion risk. Do not open the connection
box when an explosive atmosphere or dust is
present.
Always follow local regulations and legislations
for all steps in the installation process.
Figure 9. As a general