Nederman E-PAK 500 DX Hybrid Manuel D'instruction page 24

EN E-PAK 500 DX Hybrid
4.1.1
NOTE! The risk area may extend beyond the values given above. The final risk area is to
be evaluated with regards to affecting factors found in Standard EN 14491.
4.1.2
4.1.3
5
5.1
24
Method 1: Explosion relief venting
The harmful effects of an explosion are minimized by venting the pressure
and flame of the explosion through an explosion relief panel. In case of an
explosion, the resulting flame and pressure escape through the explosion relief
panel which is to be directed towards a safe area without any people. This
area is referred to as the 'risk area'.
The risk area is to be clearly marked, for example with a fence, warning lines
and signs, and entry is prohibited when the filter is in operation. The area is to
be free of any flammable or combustible material or other objects which may
be damaged by the flames and explosion pressure.
The general size of the risk area is shown in Figure 5. The following dimensions
apply:
• A = 10 m (32.8 ft)
• B = 5 m (16.4 ft)
Method 2: Explosion suppression system
With an explosion suppression system, the early stage of an explosion is
detected with optical and/or pressure-sensitive devices, and an extinguishing
agent is quickly dispersed into the filter. The suppression of the explosion
is initiated an extremely short time after detection of the explosion (in
milliseconds), and stops the pressure rising and extinguishes (suppresses) the
flames of the explosion.
This ensures that the filter is not stressed to a dangerous level by the
explosion.
The key components of the explosion suppression system are the following:
• An explosion detection device (optical/pressure-sensitive).
• A computer-operated control unit.
• Action elements such as pressure cylinders containing an extinguish
agent with an extra fast opening valve.
Detailed information regarding system installation, function, operation and
maintenance can be found in the suppression system manual.
Isolation device
An isolation device, see Figure 6, item 5, is to be installed to prevent a filter
explosion from propagating back into the plant through the connected duct.
The duct, see Figure 6, item 7, between the unit and the isolation device is to
be pressure-resistant to an overpressure of at least 0.5 bar (7.2 PSI) and have
a minimum length (Figure 6, item A) as specified in the manual of the isolation
device.
Description
Function
E-PAK 500 DX Hybrid has been designed to filter combustible and non-
combustible dust in a high vacuum system.