Flame arrester
Flame arresters are fixtures that are designed to prevent the propagation of an explosion in other parts of the plant. They must be installed in particular when an explosive gas -air mixture can form and an explosion can propagate in containers or plant parts that are not designed explosion-proof. These facilities should be limited to a manageable level in the event of an explosion the effect. Flame arresters are devices for explosion protection. They are also referred to as a flame arrester or Kito. Kito is the abbreviation for gravel pot. This is the original design of the flame arrester.
Flame arresters are typically on the European standard EN ISO 16852:2010 defines which was adopted as the German standard. The EN ISO 16852:2010 EN 12874:2001 replaced the former.
The effect is based on that a flame front is cooled by internals (eg wound sieve plates, gravel ) to the extent that a flame can not spread further behind the flame arrester. A distinction is made between:
- Deflagration and
- Detonation arresters.
Which type is used by flame arresters depends in practice on media, distance to source of ignition and of the application ( tube fuse, end stop ) from.
Definitions
The deflagration is to prevent the spread of an " explosion " in a piping system ( a certified only for deflagration flame arrester must be monitored by a temperature sensor ) Upstream and downstream straight pipe lines shall have a ratio of diameter to length (D / L) of 1:50 not exceed.
The duration of fire safety secures the system against deflagration ( explosion ), post-and endurance burning.
The detonation safety stops / destroyed the effect of a gas explosion and prevents the spread of a Nachbrandes. A condition for a detonation can only in a straight pipe from a ratio D / L result of greater than 1:200 - straight pipes between the D / L ratios 1:50 - 1:200 and should be avoided (these may be unstable - uncontrollable deflagration / detonation conditions lead ). Characterized by a detonation flame speeds in the supersonic range (about 1600-2000 m / s). Deflagrationsrohrsicherungen have very close behind the potential ignition source ( max. distance 30 x 50 x DN or DN [ depending on the medium and the authorization ] ) must be installed. The flames spread through a detonation in the more distant parts of the plant can be prevented by detonation flame arresters.
Flame arresters that are shipped with a temperature sensor and used, are short time burning and endurance burning. Flame arresters that are supplied with two temperature sensors per fitting and used are suitable for bi -directional use.
Endsicherungen ( on tanks and vent lines ), however, are deflagration, as they are installed at the source of ignition at the junction of ventilation duct to the atmosphere. Endsicherungen are often permanently fire-resistant, that is a longer lasting fire does not lead to a deterioration of the security device due to the heating of the valve. Endsicherungen who are not endurance burning, can be equipped with a temperature sensor which automatically initiates the interruption of the gas flow, eg by closing a valve or a pump shutdown.
Areas of application
- Biogas plants
- Sewage gas
- Mine gas utilization
- Ventilation of tank farms
- ATEX 94/9/EC
- EN ISO 16852:2010
- EN 12874:2001
- EN 1127-1:1997
- Eccentric
- Concentric
- 30 ° taper
- 2xDN larger filter element
Other embodiments
- Wassertauchungen,
- Fluid closures ( with liquid product as a barrier; structure as a siphon )
- High-speed valves (so-called dynamic flame arrester )
- Automatic extinguishing barriers and
- Rotary.
On immersions a potentially explosive gas mixture is passed through water at a safe minimum height. The water seal prevents so backward propagation of an explosion.
Automatic Chemical barriers are used in conjunction with infrared flame detectors that initiate the release of the pressurized extinguishing agent and therefore put out a fire and possibly prevent the further influx of the explosive mixture.
- Pyrotechnics
- Brand doctrine
- Explosion protection