Long Burning Proof End Of Line Flame Arrestors, In Line Flame Arrestors, Confined Deflagration Flame Arrestors, In Line Confined Deflagration Flame Arrestors

TYPES OF FLAME ARRESTORS

• End Of Line ( Un Confined Deflagration ) Flame Arrestors.
• End Of Line Long Burning Proof Flame Arrestors.
• In Line ( Confined Deflagration ) Flame Arrestor.  

The main point of concern when selecting an arrestor for end of line application are as follows—

Long burning proof end of line flame arrestors are designed for atmospheric explosion or unconfined deflagration. they simply boltedor screwed on to the vessel or tank vent.

These design incorporate advance technology. Most use multy element or crimped wound metal ribbon with a radiation gap between each element which provides the heat transfer by two different ways. Heat transfer by conduction & by radiation.

A confined detonation is result of an explosion in a pipe line where the flame moves increasingly compressed by the increased volume os unburnt gases. The flame velocity increases rapidly and combustion process changes after a certain distance from an explosion to a detonation due to the residual unburnt gases being compressed to the point of self ignition. Starting from on initial pressure of 1 bar, flame front velocities more than 2000 meters / sec, with air gas mixtures are possible and pressure peaks with a static load more than 80 bars may occur in the direction of detonation wave. The point of change from explosion to detonation is in part dependent up on the relation ship between the pipe length & it’s diameter.

If a flame arrestor is installed in a pipe line at a distance from the possible point of ignition is not more than 20 times nominal pipe diameter, an explosion will occur and not a detonation .but if, a flame arrestor is installed in a pipe line at a distance from possible point of ignition is more than 20 times nominal pipe diameter or minimum length of 2 meters detonation will occur, and a detonation proof flame arrestor must be installed.

The flame arrestor that are intended to be mounted on a pipe line caused a more confined space as a pipeline, the propagation of flame front is defined as a deflagration. a confined deflagration is a flame front travelling at a speed less than the speed of sound in the area where the flame front is constrained by external boundary. in this case the pipe accelerate rapidly, this acceleration is the result of the turbulence of unburnt vapours directly in front of the flame. this happen fast and can turn catastrophic. this stated dynamic condition resulted to provide a flame arrestor product which stop the propagation of flame front and with stand the enourmous pressure caused by explosions within the confined piping.

The very wide range of possible behavior for confined flame causes two particular problems or the flame arrestor products. first , the high pressure deflagration & stable detonation states have very stable kinetics of burning and the flame is moving very fast. therefore the arrestor must be able to absorb the flame’s heat much faster than required by standard low- to – medium pressure deflagration conditions.

Second , the instantaneous impulse pressure caused by the shock waves of overdriven detonation subject the arrestor to force of up to 40 bar. thus the arrestor must be structurally superiors standard low pressure deflagration arrestors.

Elements consists of alternate layers of crimped and uncrimped metal built into a circular frame in either case this results in structure with many approximately triangular shaped apparatus.

This types of arrestors can be made to very close tolerance & dimensions can be varied over a range . the pressure drop across the arrestor is low and they can be constructed to with stand to mot severe explosion.