4 replies to this topic

[Afshin445]

Dear Experts,

 

Currently I am working in project which is contain designing of a new diesel storage tank

for gravity feeding to new Diesel Engine Generator (DEG) (Refer to attached sketch).

 

The tank is provided with an atmospheric vent including Flame Arrester(F.A.). Tank also located in

Non-Hazardous Area (safe area).In this regards, I need to decide about type of flame arrester as

per below:

 

1- F.A. should be deflagration or detonation type

2- F.A. should be In-line or End of Line design

 

Appreciated if somebody can help me to finalize our F.A. selection as per above request.

Attached Files

•  Storage Tank Sketch.xlsx   65.1KB   39 downloads

Edited by Afshin, 13 May 2014 - 03:18 AM.

[fallah]

Afshin,

 

Regarding the type of the arrester to be used, as far as i know it depends on the distance between the arrester installation point and the ignition source. If mentioned distance is so short, let say less than 3 m, a deflagration arrester should be applied otherwise a detonation arrester shall be used. I think appears in your case detonation type should be used.

 

About the installation location, in my opinion in your case in which there is free venting to the atmosphere it's better using end of line design because in the in line design the goose neck can promote the turbulency of the probable flowing back might affect negatively on arrester performance to prevent the flame passing through it... 

[Afshin445]

Fallah,

 

First thanks for your response. Refer to first part of your responce appreciated if you can introduce me any reference or standard for F.A. selection in view of detonation or deflagration type.

 

Refer to 2nd part of your responce I am totally agree with you about end of line design but my understanding about the reason of choosing this type is different.

 

In my understanding in line F.A. only can be used if equipment which vent installed on that is located in Hazardous Area and vent need to routed to safe area perhaps with long piping,but in case same as my case which equipment located in safe area end of line design can be selected.

 

Appreciated if you can correct me if I am wrong.

Edited by Afshin, 13 May 2014 - 05:19 AM.

[fallah]

Afshin,

 

Actually i don't know about any standard for arrester type selection if it there is. But basically the deflagration type prevents the flame back due to "rapid burning" which is the consequence of close ignition source and the detonation type prevents that of due to "explosion" which is the consequence of not close ignition source.

 

About the installation type i just proposed end of line for your case and using in line one for long pipe away vent could be logical.

[NBD3000]

Detonation type F.A. can be used only when there is a long pipeline, where the velocity of the flame entering can reach to supersonic speed. At these speed special arrangements are made in detonation F.A. for withstanding the force. Deflagration F.A. is used for general purpose, like in tank open vent.

 

In line F.A. is used where your venting to a far place form the source and end of line is used for open venting.