No replies to this topic

[shvet]

Hi, forum

 

Now I'm in charge of feasibility study of a flare unit on a new gasoil hydrotreating unit. It is some kind of expansion/reconstruction of existing small plant and there is not so much available built-up area. The type and specifications of new flare significantly impacts on the whole plant layout. Moreover client has already chosen preliminary plant layout and based on this - flare type. The only suitable flare type to comply with this layout is enclosed flare. Now I have to find this kind of flare (and get a draft proposal(s)) or to give proof this impossible. All sounds good, but the capacity...

 

Preliminary there will be 2 key cases:

1st one - main fractionator fire ~100 t/h of gasoil vapors at ~200°C

2nd one - emergency depressuring ~120 Nm3/h of hydrogen-rich gas at 40°C@3.5 mol. weight

 

Friendly speaking 100 t/h of gasoil is based on API 537-2008 statement "The largest enclosed-flame flares now operating are rated at capacities above 90 000 kg/h (200 000 lb/h)" and preliminary firecase calculation shows up to 200 t/h of gasoil. I'm going to reduce flare load using instrumentation on HAZID stage.

 

So my questions are:

 

1. Did I understand right and enclosed flares require rather high pressure in flare header? As I understood for good work of flare burners static pressure in knock-out separator should be ~1 barg. All this leads to high back pressure in PSV.

 

2. Can you share contacts of experienced enclosed flare manufacturers who supplied enclosed flares and they are on work?

Edited by shvet, 30 July 2016 - 07:35 AM.