Monday, November 7, 2011

Re: Flare and Degassing Stacks

On 11/7/2011 6:31 PM, Harold Sprague wrote:
I am not aware of any significant thrust loads from the startup or operation of a gas flare.  The operational pressures are low.  The thrust from ignition is minimal.  A petrochemical blast from a vapor cloud in the general area could create some unintended loads.  A deflagration load can approach about 4 psi. 
I presume you are designing to STS 1?

Yes I am. The client had their junior engineers draw it up for fabrication. I pointed out that it MIGHT be a good idea if they would check the shell thickness as well. Silence.

"Um, well, they're mechanical engineers."

"Well, mechanical engineers typically design equipment structures."

"Our guys don't even know what that is."


"All right, but you'll have to pay me for it."

"No problem! Thanks!"

I had never even seen STS-1 - I thought that was the name of the first Space Shuttle mission. Anyway, I located a copy online - 2006, not 2010 or 11 or whatever. Close enough.

Wind loads are the only biggie, and I've got that covered by ASCE 7-10. STS-1 has wind load criteria but it looks like ASCE 7-95 or -98 or so.

I'm finished with the degas stack, a 45-footer. Now I hear the flare stack may be between 200 and 300 feet. They claim it's to be free-standing.

At V = 150 mph? I don't think so.