Safety Mechanisms for High Temperature/Pressure Refractory Lined Vessels

[carlosfrm]

I'm working on a project that requires fabrication of a Refractory Lined Test Vessel (It's a Reformer) with design conditions 500 psi @ 2200 F that has the potential to spontaneously ignite an increase pressure up to 1500 psi. Usually for lower temperature/pressures I'm familiar with using rupture disks and explosion doors. But this being a refractory lined vessel I'm unsure on how to proceed as the metallurgy of a rupture disk can't withstand exposure to the high heat.

I've been doing lots of research but can't find a solution to this issue, is there such a thing as refractory lined rupture disks? I was thinking that I could add a nozzle to the vessel, give it a certain length and put the rupture disk at the end and just plug the line with a ceramic fiber that could isolate it from the heat but at bursting moment it would just blow through the pipe without much restriction. Has some of you encountered this situation before or are familiar with how to overcome this? I know there's many Reformers out there that should have a solution for this, I just can't find the right literature.

Thanks in advance for your help/advice

 

[Trestala]

You might want to look at NFPA 68.

NFPA 68, "Standard on Explosion Protection by Deflagration Venting", issue effective with the applicable Addenda of the ASME Boiler and Pressure Vessel Code.

You might also want to check what local rules applies to your case.

 

[carlosfrm]

Raymond, thanks for your response, I had already taken a look at NFPA 68, it just doesn't seem to be helpful when you talk about venting high pressure vessels (at least not for an explosion scenario). I talked with people from Fike and they told me that that's is usually how they do it, they put a heat shield and then some loose refractory to protect the disk from the temperature but not the pressure. But now my worry with rupture disks are the response time when we have an over pressure caused by an internal explosion since it all happens in fractions of a second. Our worst case scenario would be, since this is an autothermal reformer, starting to insert methane and oxygen into the vessel but the burner failing, once the vessel has more pressure with the mixture it ignites causing and explosion instead of a constant combustion... Are rupture disks adequate for relieving explosions? I know that prevention is the best tool and we are talking measurements to prevent it from happening, but if it ever happens we want to be sure it can be relieved safely.