vent stack

[ratash]

Where can I find sizing procedure for vent stack diameter and height determination. I have my max blowdow rate at 1,500,000 lb/hr (799 MMscfd). Thanks.
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[MJCronin]

Suggest that you repost on the "Piping & fluid mechanic's forum"

What, exactly is being blown down...?

A boiler..? A relief valve or what..?


-MJC

 

[mizzoueng]

If this is a steam vent coming off a relief valve, height is part of the equation, so you need to know that first.

I would suggest looking up the G.S. Liao procedure. His paper is titled "Analysis of Power Plant Safety and Relief Valve Vent Stacks". It is very informative and follows ASME code for vent stack design.

 

[ratash]

Thanks. It is natural gas. We normally blowdown stations in 3 minutes, but my load is huge and would require an unreasonable stack height.

 

[RotatinSpecialist]

API RP 521 has some very useful recommendations, which are of widespread use for engineering design of vent stacks, from pressure drop calculations on vent gas lines to vent stack tip design taking into account the minimum velocity for gas dispersion. Radiation also must be taken into account, and API covers it. Even if it is a stack designed for gas dispersion with no ignition, there is always the risk of ignition, and the posible flame radiation must be considered into your design.