How does a detonation arrester differ from a deflagration arrester?
In short, the deflagration Flame Arrester is designed to stop the initial phase of the explosion and is shorter and lighter than the unstable detonation arrestor, but the Deflagration Flame Arrester has restrictions on its placement within the pipework regarding distance from the source of ignition.
How does a detonation arrester work?
How Detonation Flame Arresters Work. Flame arresters are passive devices with no moving parts. They prevent the propagation of flame from the exposed side of the unit to the protected side by the use of metal matrix creating a tortuous path called a flame cell or element.
What is the purpose of flame arrester?
A flame arrester (also spelt arrestor) is a safety device that is fitted to the opening of an enclosure, or to the connecting pipe work of a system of enclosures, and whose intended function is to allow flow but prevent the transmission of flame in the event an ignition takes place.
What is end of line flame arrester?
END OF LINE DEFLAGRANTION FLAME ARRESTORS They protect the tank or the pipe from the possible recoil of the flame coming from the outside in case of aspiration during the emptying of the tank. They are installed in the vents or at the end of the pipes.
Where are flame arrestors required?
Flame arresters are typically used wherever there is the potential for an explosion arising from flammable gas or vapour being mixed with air. Accidental ignition of a flammable mixture will result in a flame that will travel through the unburnt mixture until the fuel is consumed by the reaction.
What is the difference between spark arrestor and flame arrestor?
Most spark arresters generally perform in the high 90 percent spark arresting effectiveness range. A flame arrestor is a mesh or perforated metal insert within a flammable storage container (safety can, cabinet) which protects its contents from external flames or ignition. It also dissipates heat.
Are flame arrestors directional?
These arresters are bi-directional and capable of stopping a flame approaching from either direction in a piping system and can be mounted vertically or horizontally in the pipeline.
What is the difference between detonation and combustion?
Detonation differs from normal combustion in its ignition mechanism and in the supersonic velocity of 2–5 kilometres per second for gases and 8–9 kilometres per second for solid and liquid explosives. Detonation is impossible when the energy loss from the reaction zone exceeds a certain limit.
When should a flame arrestor be installed?
Every point of discharge of methane from a pipeline into the atmosphere or into a compressor or pump should be fitted with a flame arrestor. 2.
What is difference between NRV and flashback arrestor?
A flashback arrestor should not be confused with a non-return valve, which has no particular flame stopping properties. A non-return valve can reduce the probability of a flashback, as it serves to prevent reverse flow of oxygen into fuel lines and fuel into oxygen lines.
Where are flame arrestors used?
Some common objects that have flame arresters are:
- Fuel storage tank vents.
- Fuel gas pipelines.
- Safety storage cabinets for paint, aerosol cans, and other flammable mixtures.
- The exhaust system of internal combustion engines.
- The air intake of marine inboard engines.
- Davy lamps in coal mining.
Is detonation same as explosion?
Discovered in 1881 by French scientists, detonation is the result of a supersonic wave initiating a secondary explosion.
Does LPG require flashback arrestor?
If the LPG or fule cylinder is coupled with oxygen cylinder, there is pressure difference which may cause flash back in any of the cylinder due to blockage of nozzels. Hence flash back arrestor is required.
When should flashback arrestors be used?
A flashback arrestor or flash arrestor is a gas safety device most commonly used in oxy-fuel welding and cutting to stop the flame or reverse flow of gas back up into the equipment or supply line. It protects the user and equipment from damage or explosions.
Is detonation the same as combustion?
Detonation is spontaneous combustion inside the cylinder AFTER the spark plug fires. It is similar to Pre-Ignition, but it is different. During normal ignition, the spark plug fires just before the piston reaches TDC. The flame travels across the combustion chamber igniting the Air/Fuel Mixture.
Is knocking and detonation same?
In general, detonation is the cause and knocking is the after effect. Those who deal the terms knocking and detonation as a separate phenomenon, do so by referring auto-ignition theory as knocking and detonation theory as detonation. So, depending on the context it can mean the same thing or different thing.
What are the four components of a flashback arrestor?
The following safety valves are built into the flashback arrestor:
- A reverse-flow check valve.
- A pressure-sensitive cut-off valve that cuts off gas flow if an explosion occurs.
- A stainless steel filter that stops the flame.
- A heat-sensitive check valve that stops the gas flow if the arrestor reaches 220°F (104°C).
What is the difference between flashback arrestor and check valve?
Check Valves and Flashback Arrestors are safety devices for protecting workers using oxyfuel cutting and welding equipment. A check valve is a device that is designed to prevent the unintentional backflow of gases. A flashback (flame) arrestor is a device that prevents the propagation of a flame upstream.
What is the difference between detonation and preignition?
Preignition is caused by the presence of something in the cylinder hot enough to act as an ignition source. Detonation is caused by anything that adds heat to the last small volumes of unburned mixture out near the cylinder wall.
Are flame and detonation arresters rated for use with chemical vapors?
Flame and detonation arresters are rated for use with chemical vapors of appropriate groups defined by the National Electric Code (NEC) and the International Electrotechnical Commission (IEC). The suitability of the arrester for service with a particular vapor group must be verified.
How do detonation flame arresters work?
How Detonation Flame Arresters Work. Flame arresters are passive devices with no moving parts. They prevent the propagation of flame from the exposed side of the unit to the protected side by the use of metal matrix creating a tortuous path called a flame cell or element.
What are the classifications for a detonation arrestor?
A list from Protectoseal (www.protectoseal.com) derived from National Electric Code (NEC) Article 500 is shown below: Detonation Arrestor Certification Classes Group A- acetylene Group B- butadiene, ethylene oxide, hydrogen, manufactured gases containing more than 30% hydrogen by volume and propylene oxide
What type of detonation arrestor is suitable for methanol?
Note that a detonation arrestor certified for Group B hydrocarbons is also suitable for Group C and D hydrocarbons. There is some evidence that methanol belongs in Group C or B, but recertification is not complete.
https://www.youtube.com/watch?v=6pBBhtb8Ma0